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From:   Emmanuel Grumbach <emmanuel.grumbach@intel.com>
To:     gregkh@linuxfoundation.org, kvalo@codeaurora.org
Cc:     linux-wireless@vger.kernel.org, luca@coelho.fi,
        Emmanuel Grumbach <emmanuel.grumbach@intel.com>,
        Ayala Beker <ayala.beker@intel.com>,
        Luca Coelho <luciano.coelho@intel.com>
Subject: [PATCH RESEND 2/3] iwlwifi: mei: add the driver to allow cooperation with CSME
Date:   Mon, 12 Apr 2021 15:43:27 +0300
Message-Id: <20210412124328.24472-2-emmanuel.grumbach@intel.com>
In-Reply-To: <20210412124328.24472-1-emmanuel.grumbach@intel.com>
References: <20210412124328.24472-1-emmanuel.grumbach@intel.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
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iwlmei is a driver that handles the communication with the
Wireless driver of the CSME firmware.
More details in the documentation included in this patch.

Co-Developed-by: Ayala Beker <ayala.beker@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
---
 drivers/net/wireless/intel/iwlwifi/Kconfig    |   13 +
 drivers/net/wireless/intel/iwlwifi/Makefile   |    2 +
 .../net/wireless/intel/iwlwifi/mei/Makefile   |    8 +
 .../net/wireless/intel/iwlwifi/mei/internal.h |   20 +
 .../net/wireless/intel/iwlwifi/mei/iwl-mei.h  |  440 ++++
 drivers/net/wireless/intel/iwlwifi/mei/main.c | 2026 +++++++++++++++++
 drivers/net/wireless/intel/iwlwifi/mei/net.c  |  409 ++++
 drivers/net/wireless/intel/iwlwifi/mei/sap.h  |  736 ++++++
 .../wireless/intel/iwlwifi/mei/trace-data.h   |   69 +
 .../net/wireless/intel/iwlwifi/mei/trace.c    |   15 +
 .../net/wireless/intel/iwlwifi/mei/trace.h    |   62 +
 11 files changed, 3800 insertions(+)
 create mode 100644 drivers/net/wireless/intel/iwlwifi/mei/Makefile
 create mode 100644 drivers/net/wireless/intel/iwlwifi/mei/internal.h
 create mode 100644 drivers/net/wireless/intel/iwlwifi/mei/iwl-mei.h
 create mode 100644 drivers/net/wireless/intel/iwlwifi/mei/main.c
 create mode 100644 drivers/net/wireless/intel/iwlwifi/mei/net.c
 create mode 100644 drivers/net/wireless/intel/iwlwifi/mei/sap.h
 create mode 100644 drivers/net/wireless/intel/iwlwifi/mei/trace-data.h
 create mode 100644 drivers/net/wireless/intel/iwlwifi/mei/trace.c
 create mode 100644 drivers/net/wireless/intel/iwlwifi/mei/trace.h

diff --git a/drivers/net/wireless/intel/iwlwifi/Kconfig b/drivers/net/wireless/intel/iwlwifi/Kconfig
index 1085afbefba8..eb68f93bbe90 100644
--- a/drivers/net/wireless/intel/iwlwifi/Kconfig
+++ b/drivers/net/wireless/intel/iwlwifi/Kconfig
@@ -92,6 +92,19 @@ config IWLWIFI_BCAST_FILTERING
 	  If unsure, don't enable this option, as some programs might
 	  expect incoming broadcasts for their normal operations.
 
+config IWLMEI
+	tristate "Enable V-PRO for WLAN"
+	depends on INTEL_MEI
+	depends on IWLMVM
+	help
+	  Enable V-PRO. This allows to communicate with the CSME firmware.
+	  This is supported starting from Tiger Lake platforms and has been
+	  tested on 9260 devices only. Enabling this option on a platform that
+	  has a different device and has Wireless enabled on AMT can prevent
+	  WiFi from working correctly.
+
+	  If unsure, say N.
+
 menu "Debugging Options"
 
 config IWLWIFI_DEBUG
diff --git a/drivers/net/wireless/intel/iwlwifi/Makefile b/drivers/net/wireless/intel/iwlwifi/Makefile
index 14b0db28143b..ff4d4b651c3e 100644
--- a/drivers/net/wireless/intel/iwlwifi/Makefile
+++ b/drivers/net/wireless/intel/iwlwifi/Makefile
@@ -30,4 +30,6 @@ ccflags-y += -I$(src)
 obj-$(CONFIG_IWLDVM)	+= dvm/
 obj-$(CONFIG_IWLMVM)	+= mvm/
 
+obj-$(CONFIG_IWLMEI)	+= mei/
+
 CFLAGS_iwl-devtrace.o := -I$(src)
diff --git a/drivers/net/wireless/intel/iwlwifi/mei/Makefile b/drivers/net/wireless/intel/iwlwifi/mei/Makefile
new file mode 100644
index 000000000000..f897951ab21b
--- /dev/null
+++ b/drivers/net/wireless/intel/iwlwifi/mei/Makefile
@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: GPL-2.0
+obj-$(CONFIG_IWLMEI)	+= iwlmei.o
+iwlmei-y += main.o
+iwlmei-y += net.o
+iwlmei-$(CONFIG_IWLWIFI_DEVICE_TRACING) += trace.o
+CFLAGS_trace.o := -I$(src)
+
+ccflags-y += -I$(src)/../
diff --git a/drivers/net/wireless/intel/iwlwifi/mei/internal.h b/drivers/net/wireless/intel/iwlwifi/mei/internal.h
new file mode 100644
index 000000000000..1126c65998ec
--- /dev/null
+++ b/drivers/net/wireless/intel/iwlwifi/mei/internal.h
@@ -0,0 +1,20 @@
+// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+/*
+ * Copyright (C) 2021 Intel Corporation
+ */
+
+#ifndef __IWLMEI_INTERNAL_H_
+#define __IWLMEI_INTERNAL_H_
+
+#include <uapi/linux/if_ether.h>
+#include <linux/netdevice.h>
+
+#include "sap.h"
+
+rx_handler_result_t iwl_mei_rx_filter(struct sk_buff *skb,
+				      const struct iwl_sap_oob_filters *filters,
+				      bool *pass_to_csme);
+
+void iwl_mei_add_data_to_ring(struct sk_buff *skb, bool cb_tx);
+
+#endif /* __IWLMEI_INTERNAL_H_ */
diff --git a/drivers/net/wireless/intel/iwlwifi/mei/iwl-mei.h b/drivers/net/wireless/intel/iwlwifi/mei/iwl-mei.h
new file mode 100644
index 000000000000..cf965fa9b6b5
--- /dev/null
+++ b/drivers/net/wireless/intel/iwlwifi/mei/iwl-mei.h
@@ -0,0 +1,440 @@
+// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+/*
+ * Copyright (C) 2021 Intel Corporation
+ */
+
+#ifndef __iwl_mei_h__
+#define __iwl_mei_h__
+
+#include <linux/if_ether.h>
+#include <linux/skbuff.h>
+#include <linux/ieee80211.h>
+
+/**
+ * DOC: Introduction
+ *
+ * iwlmei is the kernel module that is in charge of the commnunication between
+ * the iwlwifi driver and the CSME firmware's WLAN driver. This communication
+ * uses the SAP protocol defined in another file.
+ * iwlwifi can request or release ownership on the WiFi device through iwlmei.
+ * iwlmei may notify iwlwifi about certain events: what filter iwlwifi should
+ * use to passthrough inbound packets to the CSME firmware for example. iwlmei
+ * may also use iwlwifi to send traffic. This means that we need communication
+ * from iwlmei to iwlwifi and the other way around.
+ */
+
+/**
+ * DOC: Life cycle
+ *
+ * iwlmei exports symbols that are needed by iwlwifi so that iwlmei will always
+ * be loaded when iwlwifi is alive. iwlwifi registers itself to iwlmei and
+ * provides the pointers to the functions that iwlmei calls whenever needed.
+ * iwlwifi calls iwlmei through direct and context-free function calls.
+ * It is assumed that only one device is accessible to the CSME firmware and
+ * under the scope of iwlmei so that it is valid not to have any context passed
+ * to iwlmei's functions.
+ *
+ * There are cases in which iwlmei can't access the CSME firmware, because the
+ * CSME firmware is undergoing a reset, or the mei bus decided to unbind the
+ * device. In those cases, iwlmei will need not to send requests over the mei
+ * bus. Instead, it needs to cache the requests from iwlwifi and fulfill them
+ * when the mei bus is available again.
+ *
+ * iwlmei can call iwlwifi as long as iwlwifi is registered to iwlmei. When
+ * iwlwifi goes down (the PCI device is unbound, or the iwlwifi is unloaded)
+ * iwlwifi needs to unregister from iwlmei.
+ */
+
+/**
+ * DOC: Memory layout
+ *
+ * Since iwlwifi calls iwlmei without any context, iwlmei needs to hold a
+ * global pointer to its data (which is in the mei client device's private
+ * data area). If there was no bind on the mei bus, this pointer is NULL and
+ * iwlmei knows not access to the CSME firmware upon requests from iwlwifi.
+ *
+ * iwlmei needs to cache requests from iwlwifi when there is no mei client
+ * device available (when iwlmei has been removed from the mei bus). In this
+ * case, all iwlmei's data that resides in the mei client device's private data
+ * area is unavailable. For this specific case, a separate caching area is
+ * needed.
+ */
+
+/**
+ * DOC: Concurrency
+ *
+ * iwlwifi can call iwlmei at any time. iwlmei will take care to synchronize
+ * the calls from iwlwifi with its internal flows. iwlwifi must not call iwlmei
+ * in flows that cannot sleep. Moreover, iwlwifi must not call iwlmei in flows
+ * that originated from iwlmei.
+ */
+
+/**
+ * DOC: Probe and remove from mei bus driver
+ *
+ * When the mei bus driver enumerates its devices, it calls the iwlmei's probe
+ * function which will send the %SAP_ME_MSG_START message. The probe completes
+ * before the response (%SAP_ME_MSG_START_OK) is received. This response will
+ * be handle by the Rx path. Once it arrives, the connection to the CSME
+ * firmware is considered established and iwlwifi's requests can be treated
+ * against the CSME firmware.
+ *
+ * When the mei bus driver removes the device, iwlmei loses all the data that
+ * was attached to the mei client device. It clears the global pointer to the
+ * mei client device since it is not available anymore. This will cause all the
+ * requests coming from iwlwifi to be cached. This flow takes the global mutex
+ * to be synchronized with all the requests coming from iwlwifi.
+ */
+
+/**
+ * DOC: Driver load when CSME owns the device
+ *
+ * When the driver (iwlwifi) is loaded while CSME owns the device,
+ * it'll ask CSME to release the device through HW registers. CSME
+ * will release the device only in the case that there is no connection
+ * through the mei bus. If there is a mei bus connection, CSME will refuse
+ * to release the ownership on the device through the HW registers. In that
+ * case, iwlwifi must first request ownership using the SAP protocol.
+ *
+ * Once iwlwifi will request ownership through the SAP protocol, CSME will
+ * grant the ownership on the device through the HW registers as well.
+ * In order to request ownership over SAP, we first need to have an interface
+ * which means that we need to register to mac80211.
+ * This can't happen before we get the NVM that contains all the capabilities
+ * of the device. Reading the NVM usually requires the load the firmware, but
+ * this is impossible as long as we don't have ownership on the device.
+ * In order to solve this chicken and egg problem, the host driver can get
+ * the NVM through CSME which owns the device. It can send
+ * %SAP_MSG_NOTIF_GET_NVM, which will be replied by %SAP_MSG_NOTIF_NVM with
+ * the NVM's content that the host driver needs.
+ */
+
+/**
+ * DOC: Driver load when CSME is associated and a session is active
+ *
+ * A "session" is active when CSME is associated to an access point and the
+ * link is used to attach a remote driver or to control the system remotely.
+ * When a session is active, we want to make sure it won't disconnect when we
+ * take ownership on the device.
+ * In this case, the driver can get the device, but it'll need to make
+ * sure that it'll connect to the exact same AP (same BSSID).
+ * In order to do so, CSME will send the connection parameters through
+ * SAP and then the host can check if it can connect to this same AP.
+ * If yes, it can request ownership through SAP and connect quickly without
+ * scanning all the channels, but just probing the AP on the channel that
+ * CSME was connected to.
+ * In order to signal this specific scenario to iwlwifi, iwlmei will
+ * immediately require iwlwifi to report RF-Kill to the network stack. This
+ * RF-Kill will prevent the stack from getting the device, and it has a reason
+ * that tells the userspace that the device is in RF-Kill because it is not
+ * owned by the host. Once the userspace has configured the right profile,
+ * it'll be able to let iwlmei know that it can request ownership over SAP
+ * which will remove the RF-Kill, and finally allow the host to connect.
+ * The host has then 3 seconds to connect (including DHCP). Had the host
+ * failed to connect within those 3 seconds, CSME will take the device back.
+ */
+
+/**
+ * DOC: Datapath
+ *
+ * CSME can transmit packets, through the netdev that it gets from the wifi
+ * driver. It'll send packet in the 802.3 format and simply call
+ * dev_queue_xmit.
+ *
+ * For Rx, iwlmei registers a Rx handler that it attaches to the netdev. iwlmei
+ * may catch packets and send them to CSME, it can then either drop them so
+ * that they are invisible to user space, or let them go the user space.
+ *
+ * Packets transmitted by the user space do not need to be forwarded to CSME
+ * with the exception of the DHCP request. In order to know what IP is used
+ * by the user space, CSME needs to get the DHCP request. See
+ * iwl_mei_tx_copy_to_csme().
+ */
+
+/**
+ * enum iwl_mei_nvm_caps - capabilities for MEI NVM
+ * @MEI_NVM_CAPS_LARI_SUPPORT: Lari is supported
+ * @MEI_NVM_CAPS_11AX_SUPPORT: 11AX is supported
+ */
+enum iwl_mei_nvm_caps {
+	MEI_NVM_CAPS_LARI_SUPPORT	= BIT(0),
+	MEI_NVM_CAPS_11AX_SUPPORT	= BIT(1),
+};
+
+/**
+ * struct iwl_mei_nvm - used to pass the NVM from CSME
+ * @hw_addr: The MAC address
+ * @n_hw_addrs: The number of MAC addresses
+ * @reserved: For alignment.
+ * @radio_cfg: The radio configuration.
+ * @caps: See &enum iwl_mei_nvm_caps.
+ * @nvm_version: The version of the NVM.
+ * @channels: The data for each channel.
+ *
+ * If a field is added, it must correspond to the SAP structure.
+ */
+struct iwl_mei_nvm {
+	u8 hw_addr[ETH_ALEN];
+	u8 n_hw_addrs;
+	u8 reserved;
+	u32 radio_cfg;
+	u32 caps;
+	u32 nvm_version;
+	u32 channels[110];
+};
+
+/**
+ * struct iwl_mei_conn_info - connection info
+ * @lp_state: link protection state
+ * @auth_mode: authentication mode
+ * @ssid_len: the length of SSID
+ * @ssid: the SSID
+ * @ucast_cipher: the cipher used for unicast packets
+ * @channel: the associated channel
+ * @band: the associated band
+ * @bssid: the BSSID
+ */
+struct iwl_mei_conn_info {
+	u8 lp_state;
+	u8 auth_mode;
+	u8 ssid_len;
+	u8 channel;
+	u8 band;
+	u8 ucast_cipher;
+	u8 bssid[ETH_ALEN];
+	u8 ssid[IEEE80211_MAX_SSID_LEN];
+};
+
+/**
+ * struct iwl_mei_colloc_info - collocated AP info
+ * @channel: the channel of the collocated AP
+ * @bssid: the BSSID of the collocated AP
+ */
+struct iwl_mei_colloc_info {
+	u8 channel;
+	u8 bssid[ETH_ALEN];
+};
+
+/*
+ * struct iwl_mei_ops - driver's operations called by iwlmei
+ * Operations will not be called more than once concurrently.
+ * It's not allowed to call iwlmei functions from this context.
+ *
+ * @me_conn_status: provide information about CSME's current connection.
+ * @rfkill: called when the wifi driver should report a change in the rfkill
+ *	status.
+ * @roaming_forbidden: indicates whether roaming is forbidden.
+ * @sap_connected: indicate that SAP is now connected. Will be called in case
+ *	the wifi driver registered to iwlmei before SAP connection succeeded or
+ *	when the SAP connection is re-established.
+ * @nic_stolen: this means that device is no longer available. The device can
+ *	still be used until the callback returns.
+ */
+struct iwl_mei_ops {
+	void (*me_conn_status)(void *priv,
+			       const struct iwl_mei_conn_info *conn_info);
+	void (*rfkill)(void *priv, bool blocked);
+	void (*roaming_forbidden)(void *priv, bool forbidden);
+	void (*sap_connected)(void *priv);
+	void (*nic_stolen)(void *priv);
+};
+
+#if IS_ENABLED(CONFIG_IWLMEI)
+
+/**
+ * iwl_mei_is_connected() - is the connection to the CSME firmware established?
+ *
+ * Return: true if we have a SAP connection
+ */
+bool iwl_mei_is_connected(void);
+
+/**
+ * iwl_mei_get_nvm() - returns the NVM for the device
+ *
+ * It is the caller's responsibility to free the memory returned
+ * by this function.
+ * This function blocks (sleeps) until the NVM is ready.
+ *
+ * Return: the NVM as received from CSME
+ */
+struct iwl_mei_nvm *iwl_mei_get_nvm(void);
+
+/**
+ * iwl_mei_get_ownership() - request ownership
+ *
+ * This function blocks until ownership is granted or timeout expired.
+ *
+ * Return: 0 in case we could get ownership on the device
+ */
+int iwl_mei_get_ownership(void);
+
+/**
+ * iwl_mei_set_rfkill_state() - set SW and HW RF kill states
+ * @hw_rfkill: HW RF kill state.
+ * @sw_rfkill: SW RF kill state.
+ *
+ * This function must be called when SW RF kill is issued by the user.
+ */
+void iwl_mei_set_rfkill_state(bool hw_rfkill, bool sw_rfkill);
+
+/**
+ * iwl_mei_set_nic_info() - set mac address
+ * @mac_address: mac address to set
+ * @nvm_address: NVM mac adsress to set
+ *
+ * This function must be called upon mac address change.
+ */
+void iwl_mei_set_nic_info(const u8 *mac_address, const u8 *nvm_address);
+
+/**
+ * iwl_mei_set_country_code() - set new country code
+ * @mcc: the new applied MCC
+ *
+ * This function must be called upon country code update
+ */
+void iwl_mei_set_country_code(u16 mcc);
+
+/**
+ * iwl_mei_set_power_limit() - set TX power limit
+ * @power_limit: pointer to an array of 10 elements (le16) represents the power
+ * restrictions per chain.
+ *
+ * This function must be called upon power restrictions change
+ */
+void iwl_mei_set_power_limit(const __le16 *power_limit);
+
+/**
+ * iwl_mei_register() - register the wifi driver to iwlmei
+ * @priv: a pointer to the wifi driver's context. Cannot be NULL.
+ * @ops: the ops structure.
+ *
+ * Return: 0 unless something went wrong. It is illegal to call any
+ * other API function before this function is called and succeeds.
+ *
+ * Only one wifi driver instance (wifi device instance really)
+ * can register at a time.
+ */
+int iwl_mei_register(void *priv, const struct iwl_mei_ops *ops);
+
+/**
+ * iwl_mei_start_unregister() - unregister the wifi driver from iwlmei
+ *
+ * From this point on, iwlmei will not used the callbacks provided by
+ * the driver, but the device is still usable.
+ */
+void iwl_mei_start_unregister(void);
+
+/**
+ * iwl_mei_unregister_complete() - complete the unregistration
+ *
+ * Must be called after iwl_mei_start_unregister. When this function returns,
+ * the device is owned by CSME.
+ */
+void iwl_mei_unregister_complete(void);
+
+/**
+ * iwl_mei_set_netdev() - sets the netdev for Tx / Rx.
+ * @netdev: the net_device
+ *
+ * The caller should set the netdev to a non-NULL value when the
+ * interface is added. Packets might be sent to the driver immediately
+ * afterwards.
+ * The caller should set the netdev to NULL when the interface is removed.
+ * This function will call synchronize_net() after setting the netdev to NULL.
+ * Only when this function returns, can the caller assume that iwlmei will
+ * no longer inject packets into the netdev's Tx path.
+ *
+ * Context: This function can sleep and assumes rtnl_lock is taken.
+ * The netdev must be set to NULL before iwl_mei_start_unregister() is called.
+ */
+void iwl_mei_set_netdev(struct net_device *netdev);
+
+/**
+ * iwl_mei_tx_copy_to_csme() - must be called for each packet sent by
+ * the wifi driver.
+ * @skb: the skb sent
+ * @ivlen: the size of the IV that needs to be skipped after the MAC and
+ *	before the SNAP header.
+ *
+ * This function doesn't take any lock, it simply tries to catch DHCP
+ * packets sent by the wifi driver. If the packet is a DHCP packet, it
+ * will send it to CSME. This function must not be called for virtual
+ * interfaces that are not monitored by CSME, meaning it must be called
+ * only for packets transmitted by the netdevice that was registered
+ * with iwl_mei_set_netdev().
+ */
+void iwl_mei_tx_copy_to_csme(struct sk_buff *skb, unsigned int ivlen);
+
+/**
+ * iwl_mei_host_associated() - must be called when iwlwifi associated.
+ * @conn_info: pointer to the connection info structure.
+ * @colloc_info: pointer to the collocated AP info. This is relevant only in
+ *	case of UHB associated AP, otherwise set to NULL.
+ */
+void iwl_mei_host_associated(const struct iwl_mei_conn_info *conn_info,
+			     const struct iwl_mei_colloc_info *colloc_info);
+
+/**
+ * iwl_mei_host_disassociated() - must be called when iwlwifi disassociated.
+ * @type: See &enum iwl_sap_notif_link_down_type.
+ */
+void iwl_mei_host_disassociated(u8 type);
+
+/**
+ * iwl_mei_device_down() - must be called when the device is down
+ */
+void iwl_mei_device_down(void);
+
+#else
+
+static inline bool iwl_mei_is_connected(void)
+{ return false; }
+
+static inline struct iwl_mei_nvm *iwl_mei_get_nvm(void)
+{ return NULL; }
+
+static inline int iwl_mei_get_ownership(void)
+{ return 0; }
+
+static inline void iwl_mei_set_rfkill_state(bool hw_rfkill, bool sw_rfkill)
+{}
+
+static inline void iwl_mei_set_nic_info(const u8 *mac_address, const u8 *nvm_address)
+{}
+
+static inline void iwl_mei_set_country_code(u16 mcc)
+{}
+
+static inline void iwl_mei_set_power_limit(__le16 *power_limit)
+{}
+
+static inline int iwl_mei_register(void *priv,
+				   const struct iwl_mei_ops *ops)
+{ return 0; }
+
+static inline void iwl_mei_start_unregister(void)
+{}
+
+static inline void iwl_mei_unregister_complete(void)
+{}
+
+static inline void iwl_mei_set_netdev(struct net_device *netdev)
+{}
+
+static inline void iwl_mei_tx_copy_to_csme(struct sk_buff *skb,
+					   unsigned int ivlen)
+{}
+
+static inline void iwl_mei_host_associated(const struct iwl_mei_conn_info *conn_info,
+					   const struct iwl_mei_colloc_info *colloc_info)
+{}
+
+static inline void iwl_mei_host_disassociated(u8 type)
+{}
+
+static inline void iwl_mei_device_down(void)
+{}
+
+#endif /* CONFIG_IWLMEI */
+
+#endif /* __iwl_mei_h__ */
diff --git a/drivers/net/wireless/intel/iwlwifi/mei/main.c b/drivers/net/wireless/intel/iwlwifi/mei/main.c
new file mode 100644
index 000000000000..43347f84eb74
--- /dev/null
+++ b/drivers/net/wireless/intel/iwlwifi/mei/main.c
@@ -0,0 +1,2026 @@
+// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+/*
+ * Copyright (C) 2021 Intel Corporation
+ */
+
+#include <linux/etherdevice.h>
+#include <linux/netdevice.h>
+#include <linux/rtnetlink.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/mei_cl_bus.h>
+#include <linux/rcupdate.h>
+#include <linux/debugfs.h>
+#include <linux/skbuff.h>
+#include <linux/wait.h>
+#include <linux/slab.h>
+#include <linux/mm.h>
+
+#include "internal.h"
+#include "iwl-mei.h"
+#include "trace.h"
+#include "trace-data.h"
+#include "sap.h"
+
+MODULE_DESCRIPTION("The Intel(R) wireless / CSME firmware interface");
+MODULE_LICENSE("GPL");
+
+#define CHECK_FOR_NEWLINE(f) BUILD_BUG_ON(f[sizeof(f) - 2] != '\n')
+
+#define IWL_MEI_DEBUG(c, f, a...)		\
+	do {					\
+		CHECK_FOR_NEWLINE(f);		\
+		dev_dbg(&(c)->dev, f, ## a);	\
+	} while (0)
+
+#define IWL_MEI_INFO(c, f, a...)		\
+	do {					\
+		CHECK_FOR_NEWLINE(f);		\
+		dev_info(&(c)->dev, f, ## a);	\
+	} while (0)
+
+#define IWL_MEI_ERR(c, f, a...)			\
+	do {					\
+		CHECK_FOR_NEWLINE(f);		\
+		dev_err(&(c)->dev, f, ## a);	\
+	} while (0)
+
+#define MEI_WLAN_UUID UUID_LE(0x13280904, 0x7792, 0x4fcb, \
+			      0xa1, 0xaa, 0x5e, 0x70, 0xcb, 0xb1, 0xe8, 0x65)
+
+/*
+ * Since iwlwifi calls iwlmei without any context, hold a pointer to the
+ * mei_cl_device structure here.
+ * Define a mutex that will synchronize all the flows between iwlwifi and
+ * iwlmei.
+ */
+static struct mei_cl_device *iwl_mei_global_cldev;
+static DEFINE_MUTEX(iwl_mei_mutex);
+static unsigned long iwl_mei_status;
+#if IS_ENABLED(CONFIG_DEBUG_FS)
+static bool defer_start_message;
+
+module_param_named(defer_start_message, defer_start_message, bool, 0644);
+MODULE_PARM_DESC(defer_start_message,
+		 "Defer the start message Tx to CSME (default false)");
+#endif
+
+enum iwl_mei_status_bits {
+	IWL_MEI_STATUS_SAP_CONNECTED,
+};
+
+bool iwl_mei_is_connected(void)
+{
+	return test_bit(IWL_MEI_STATUS_SAP_CONNECTED, &iwl_mei_status);
+}
+EXPORT_SYMBOL(iwl_mei_is_connected);
+
+#define SAP_VERSION	3
+#define SAP_CONTROL_BLOCK_ID 0x21504153 /* SAP! in ASCII */
+
+struct iwl_sap_q_ctrl_blk {
+	__le32 wr_ptr;
+	__le32 rd_ptr;
+	__le32 size;
+};
+
+enum iwl_sap_q_idx {
+	SAP_QUEUE_IDX_NOTIF = 0,
+	SAP_QUEUE_IDX_DATA,
+	SAP_QUEUE_IDX_MAX,
+};
+
+struct iwl_sap_dir {
+	__le32 reserved;
+	struct iwl_sap_q_ctrl_blk q_ctrl_blk[SAP_QUEUE_IDX_MAX];
+};
+
+enum iwl_sap_dir_idx {
+	SAP_DIRECTION_HOST_TO_ME = 0,
+	SAP_DIRECTION_ME_TO_HOST,
+	SAP_DIRECTION_MAX,
+};
+
+struct iwl_sap_shared_mem_ctrl_blk {
+	__le32 sap_id;
+	__le32 size;
+	struct iwl_sap_dir dir[SAP_DIRECTION_MAX];
+};
+
+/*
+ * The shared area has the following layout:
+ *
+ * +-----------------------------------+
+ * |struct iwl_sap_shared_mem_ctrl_blk |
+ * +-----------------------------------+
+ * |Host -> ME data queue              |
+ * +-----------------------------------+
+ * |Host -> ME notif queue             |
+ * +-----------------------------------+
+ * |ME -> Host data queue              |
+ * +-----------------------------------+
+ * |ME -> host notif queue             |
+ * +-----------------------------------+
+ * |SAP control block id (SAP!)        |
+ * +-----------------------------------+
+ */
+
+#define SAP_H2M_DATA_Q_SZ	48256
+#define SAP_M2H_DATA_Q_SZ	24128
+#define SAP_H2M_NOTIF_Q_SZ	2240
+#define SAP_M2H_NOTIF_Q_SZ	62720
+
+#define _IWL_MEI_SAP_SHARED_MEM_SZ \
+	(sizeof(struct iwl_sap_shared_mem_ctrl_blk) + \
+	 SAP_H2M_DATA_Q_SZ + SAP_H2M_NOTIF_Q_SZ + \
+	 SAP_M2H_DATA_Q_SZ + SAP_M2H_NOTIF_Q_SZ + 4)
+
+#define ROUND_UP_TO(x, y) (((x) + (y) - 1) / (y) * (y))
+
+#define IWL_MEI_SAP_SHARED_MEM_SZ \
+	(ROUND_UP_TO(_IWL_MEI_SAP_SHARED_MEM_SZ, PAGE_SIZE))
+
+struct iwl_mei_shared_mem_ptrs {
+	struct iwl_sap_shared_mem_ctrl_blk *ctrl;
+	void *q_head[SAP_DIRECTION_MAX][SAP_QUEUE_IDX_MAX];
+};
+
+struct iwl_mei_filters {
+	struct rcu_head rcu_head;
+	struct iwl_sap_oob_filters filters;
+};
+
+/**
+ * struct iwl_mei - holds the private date for iwl_mei
+ *
+ * @get_nvm_wq: the wait queue for the get_nvm flow
+ * @send_csa_msg_wk: used to defer the transmission of the CHECK_SHARED_AREA
+ *	message. Used so that we can send CHECK_SHARED_AREA from atomic
+ *	contexts.
+ * @get_ownership_wq: the wait queue for the get_ownership_flow
+ * @shared_mem: the memory that is shared between CSME and the host
+ * @cldev: the pointer to the MEI client device
+ * @nvm: the data returned by the CSME for the NVM
+ * @filters: the filters sent by CSME
+ * @got_ownership: true if we own the device
+ * @amt_enabled: true if CSME has wireless enabled
+ * @csa_throttled: when true, we can't send CHECK_SHARED_AREA over the MEI
+ *	bus, but rather need to wait until send_csa_msg_wk runs
+ * @csme_taking_ownership: true when CSME is taking ownership. Used to remember
+ *	to send CSME_OWNERSHIP_CONFIRMED when the driver completes its down
+ *	flow.
+ * @csa_throttle_end_wk: used when &csa_throttled is true
+ * @data_q_lock: protects the access to the data queues which are
+ *	accessed without the mutex.
+ * @sap_seq_no: the sequence number for the SAP messages
+ * @seq_no: the sequence number for the SAP messages
+ * @dbgfs_dir: the debugfs dir entry
+ * @debugfs_wq: used for the ping debugfs hook, waits for the response from
+ *	CSME.
+ * @ping_pending: used for the ping debugfs hook, waits for the response from
+ *	CSME.
+ */
+struct iwl_mei {
+	wait_queue_head_t get_nvm_wq;
+	struct work_struct send_csa_msg_wk;
+	wait_queue_head_t get_ownership_wq;
+	struct iwl_mei_shared_mem_ptrs shared_mem;
+	struct mei_cl_device *cldev;
+	struct iwl_mei_nvm *nvm;
+	struct iwl_mei_filters __rcu *filters;
+	bool got_ownership;
+	bool amt_enabled;
+	bool csa_throttled;
+	bool csme_taking_ownership;
+	struct delayed_work csa_throttle_end_wk;
+	spinlock_t data_q_lock;
+
+	atomic_t sap_seq_no;
+	atomic_t seq_no;
+
+#if IS_ENABLED(CONFIG_DEBUG_FS)
+	struct dentry *dbgfs_dir;
+	wait_queue_head_t debugfs_wq;
+	bool ping_pending;
+#endif
+};
+
+/**
+ * iwl_mei_cache - cache for the parameters from iwlwifi
+ * @ops: Callbacks to iwlwifi.
+ * @netdev: The netdev that will be used to transmit / receive packets.
+ * @conn_info: The connection info message triggered by iwlwifi's association.
+ * @power_limit: pointer to an array of 10 elements (le16) represents the power
+ *	restrictions per chain.
+ * @rf_kill: rf kill state.
+ * @mcc: MCC info
+ * @mac_address: interface MAC address.
+ * @nvm_address: NVM MAC address.
+ * @priv: A pointer to iwlwifi.
+ *
+ * This used to cache the configurations coming from iwlwifi's way. The data
+ * is cached here so that we can buffer the configuration even if we don't have
+ * a bind from the mei bus and hence, on iwl_mei structure.
+ */
+static struct {
+	const struct iwl_mei_ops *ops;
+	struct net_device __rcu *netdev;
+	const struct iwl_sap_notif_connection_info *conn_info;
+	const __le16 *power_limit;
+	u32 rf_kill;
+	u16 mcc;
+	u8 mac_address[6];
+	u8 nvm_address[6];
+	void *priv;
+} iwl_mei_cache = {
+	.rf_kill = SAP_HW_RFKILL_DEASSERTED | SAP_SW_RFKILL_DEASSERTED
+};
+
+static void iwl_mei_free_shared_mem(struct mei_cl_device *cldev)
+{
+	struct iwl_mei *mei = mei_cldev_get_drvdata(cldev);
+
+	WARN_ON(mei_cldev_dma_unmap(cldev));
+	memset(&mei->shared_mem, 0, sizeof(mei->shared_mem));
+}
+
+#define HBM_DMA_BUF_ID_WLAN 1
+
+static int iwl_mei_alloc_shared_mem(struct mei_cl_device *cldev)
+{
+	struct iwl_mei *mei = mei_cldev_get_drvdata(cldev);
+	struct iwl_mei_shared_mem_ptrs *mem = &mei->shared_mem;
+
+	mem->ctrl = mei_cldev_dma_map(cldev, HBM_DMA_BUF_ID_WLAN,
+				       IWL_MEI_SAP_SHARED_MEM_SZ);
+
+	if (IS_ERR(mem->ctrl)) {
+		int ret = PTR_ERR(mem->ctrl);
+
+		IWL_MEI_ERR(cldev, "Couldn't allocate the shared memory: %d\n",
+			    ret);
+		mem->ctrl = NULL;
+
+		return ret;
+	}
+
+	memset(mem->ctrl, 0, IWL_MEI_SAP_SHARED_MEM_SZ);
+
+	return 0;
+}
+
+static void iwl_mei_init_shared_mem(struct iwl_mei *mei)
+{
+	struct iwl_mei_shared_mem_ptrs *mem = &mei->shared_mem;
+	struct iwl_sap_dir *h2m;
+	struct iwl_sap_dir *m2h;
+	int dir, queue;
+	u8 *q_head;
+
+	mem->ctrl->sap_id = cpu_to_le32(SAP_CONTROL_BLOCK_ID);
+
+	mem->ctrl->size = cpu_to_le32(sizeof(*mem->ctrl));
+
+	h2m = &mem->ctrl->dir[SAP_DIRECTION_HOST_TO_ME];
+	m2h = &mem->ctrl->dir[SAP_DIRECTION_ME_TO_HOST];
+
+	h2m->q_ctrl_blk[SAP_QUEUE_IDX_DATA].size =
+		cpu_to_le32(SAP_H2M_DATA_Q_SZ);
+	h2m->q_ctrl_blk[SAP_QUEUE_IDX_NOTIF].size =
+		cpu_to_le32(SAP_H2M_NOTIF_Q_SZ);
+	m2h->q_ctrl_blk[SAP_QUEUE_IDX_DATA].size =
+		cpu_to_le32(SAP_M2H_DATA_Q_SZ);
+	m2h->q_ctrl_blk[SAP_QUEUE_IDX_NOTIF].size =
+		cpu_to_le32(SAP_M2H_NOTIF_Q_SZ);
+
+	/* q_head points to the start of the first queue */
+	q_head = (void *)(mem->ctrl + 1);
+
+	/* Initialize the queue heads */
+	for (dir = 0; dir < SAP_DIRECTION_MAX; dir++) {
+		for (queue = 0; queue < SAP_QUEUE_IDX_MAX; queue++) {
+			mem->q_head[dir][queue] = q_head;
+			q_head +=
+				le32_to_cpu(mem->ctrl->dir[dir].q_ctrl_blk[queue].size);
+		}
+	}
+
+	*(__le32 *)q_head = cpu_to_le32(SAP_CONTROL_BLOCK_ID);
+}
+
+static ssize_t iwl_mei_write_cyclic_buf(struct mei_cl_device *cldev,
+					struct iwl_sap_q_ctrl_blk *notif_q,
+					u8 *q_head,
+					const struct iwl_sap_hdr *hdr)
+{
+	u32 rd = le32_to_cpu(READ_ONCE(notif_q->rd_ptr));
+	u32 wr = le32_to_cpu(READ_ONCE(notif_q->wr_ptr));
+	u32 q_sz = le32_to_cpu(notif_q->size);
+	size_t room_in_buf;
+	size_t tx_sz = sizeof(*hdr) + le16_to_cpu(hdr->len);
+
+	if (WARN_ON(rd > q_sz || wr > q_sz))
+		return -EINVAL;
+
+	room_in_buf = wr >= rd ? q_sz - wr + rd : rd - wr;
+
+	/* we don't have enough room for the data to write */
+	if (WARN_ON(room_in_buf < tx_sz))
+		return -ENOSPC;
+
+	if (wr + tx_sz <= q_sz) {
+		memcpy(q_head + wr, hdr, tx_sz);
+	} else {
+		memcpy(q_head + wr, hdr, q_sz - wr);
+		memcpy(q_head, (u8 *)hdr + q_sz - wr, tx_sz - (q_sz - wr));
+	}
+
+	WRITE_ONCE(notif_q->wr_ptr, cpu_to_le32((wr + tx_sz) % q_sz));
+	return 0;
+}
+
+static bool iwl_mei_host_to_me_data_pending(const struct iwl_mei *mei)
+{
+	struct iwl_sap_q_ctrl_blk *notif_q;
+	struct iwl_sap_dir *dir;
+
+	dir = &mei->shared_mem.ctrl->dir[SAP_DIRECTION_HOST_TO_ME];
+	notif_q = &dir->q_ctrl_blk[SAP_QUEUE_IDX_DATA];
+
+	if (READ_ONCE(notif_q->wr_ptr) != READ_ONCE(notif_q->rd_ptr))
+		return true;
+
+	notif_q = &dir->q_ctrl_blk[SAP_QUEUE_IDX_NOTIF];
+	return READ_ONCE(notif_q->wr_ptr) != READ_ONCE(notif_q->rd_ptr);
+}
+
+static int iwl_mei_send_check_shared_area(struct mei_cl_device *cldev)
+{
+	struct iwl_mei *mei = mei_cldev_get_drvdata(cldev);
+	struct iwl_sap_me_msg_start msg = {
+		.hdr.type = cpu_to_le32(SAP_ME_MSG_CHECK_SHARED_AREA),
+		.hdr.seq_num = cpu_to_le32(atomic_inc_return(&mei->seq_no)),
+	};
+	int ret;
+
+	lockdep_assert_held(&iwl_mei_mutex);
+
+	if (mei->csa_throttled)
+		return 0;
+
+	trace_iwlmei_me_msg(&msg.hdr, true);
+	ret = mei_cldev_send(cldev, (void *)&msg, sizeof(msg));
+	if (ret != sizeof(msg)) {
+		IWL_MEI_ERR(cldev,
+			    "failed to send the SAP_ME_MSG_CHECK_SHARED_AREA message %d\n",
+			    ret);
+		return ret;
+	}
+
+	mei->csa_throttled = true;
+
+	schedule_delayed_work(&mei->csa_throttle_end_wk,
+			      msecs_to_jiffies(100));
+
+	return 0;
+}
+
+static void iwl_mei_csa_throttle_end_wk(struct work_struct *wk)
+{
+	struct iwl_mei *mei =
+		container_of(wk, struct iwl_mei, csa_throttle_end_wk.work);
+
+	mutex_lock(&iwl_mei_mutex);
+
+	mei->csa_throttled = false;
+
+	if (iwl_mei_host_to_me_data_pending(mei))
+		iwl_mei_send_check_shared_area(mei->cldev);
+
+	mutex_unlock(&iwl_mei_mutex);
+}
+
+static int iwl_mei_send_sap_msg_payload(struct mei_cl_device *cldev,
+					struct iwl_sap_hdr *hdr)
+{
+	struct iwl_mei *mei = mei_cldev_get_drvdata(cldev);
+	struct iwl_sap_q_ctrl_blk *notif_q;
+	struct iwl_sap_dir *dir;
+	void *q_head;
+	int ret;
+
+	lockdep_assert_held(&iwl_mei_mutex);
+
+	if (WARN_ON(!mei->shared_mem.ctrl))
+		return -EINVAL;
+
+	if (!iwl_mei_is_connected())
+		return -ENODEV;
+
+	hdr->seq_num = cpu_to_le32(atomic_inc_return(&mei->sap_seq_no));
+	IWL_MEI_DEBUG(cldev, "Sending %d\n", hdr->type);
+
+	dir = &mei->shared_mem.ctrl->dir[SAP_DIRECTION_HOST_TO_ME];
+	notif_q = &dir->q_ctrl_blk[SAP_QUEUE_IDX_NOTIF];
+	q_head = mei->shared_mem.q_head[SAP_DIRECTION_HOST_TO_ME][SAP_QUEUE_IDX_NOTIF];
+	ret = iwl_mei_write_cyclic_buf(q_head, notif_q, q_head, hdr);
+
+	if (ret < 0)
+		return ret;
+
+	trace_iwlmei_sap_cmd(hdr, true);
+
+	return iwl_mei_send_check_shared_area(cldev);
+}
+
+void iwl_mei_add_data_to_ring(struct sk_buff *skb, bool cb_tx)
+{
+	struct iwl_mei *mei =
+		mei_cldev_get_drvdata(iwl_mei_global_cldev);
+	struct iwl_sap_q_ctrl_blk *notif_q;
+	struct iwl_sap_dir *dir;
+	size_t room_in_buf;
+	size_t tx_sz;
+	size_t hdr_sz;
+	u32 q_sz;
+	u32 rd;
+	u32 wr;
+	void *q_head;
+
+	/*
+	 * We access this path for Rx packets (the more common case)
+	 * and from Tx path when we send DHCP packets, the latter is
+	 * very unlikely.
+	 * Take the lock already here to make sure we see that remove()
+	 * might have cleared the IWL_MEI_STATUS_SAP_CONNECTED bit.
+	 */
+	spin_lock_bh(&mei->data_q_lock);
+
+	if (!iwl_mei_is_connected()) {
+		spin_unlock_bh(&mei->data_q_lock);
+		dev_kfree_skb(skb);
+		return;
+	}
+
+	/*
+	 * We are in a RCU critical section and the remove from the CSME bus
+	 * which would free this memory waits for the readers to complete (this
+	 * is done in netdev_rx_handler_unregister).
+	 */
+	dir = &mei->shared_mem.ctrl->dir[SAP_DIRECTION_HOST_TO_ME];
+	notif_q = &dir->q_ctrl_blk[SAP_QUEUE_IDX_DATA];
+	q_head = mei->shared_mem.q_head[SAP_DIRECTION_HOST_TO_ME][SAP_QUEUE_IDX_DATA];
+
+	rd = le32_to_cpu(READ_ONCE(notif_q->rd_ptr));
+	wr = le32_to_cpu(READ_ONCE(notif_q->wr_ptr));
+	q_sz = le32_to_cpu(notif_q->size);
+	hdr_sz = cb_tx ? sizeof(struct iwl_sap_cb_data) :
+			 sizeof(struct iwl_sap_hdr);
+	tx_sz = skb->len + hdr_sz;
+
+	if (WARN_ON(rd > q_sz || wr > q_sz))
+		goto out;
+
+	room_in_buf = wr >= rd ? q_sz - wr + rd : rd - wr;
+
+	/* we don't have enough room for the data to write */
+	if (WARN_ON(room_in_buf < tx_sz))
+		goto out;
+
+	if (WARN_ON_ONCE(skb_headroom(skb) < hdr_sz))
+		goto out;
+
+	if (cb_tx) {
+		struct iwl_sap_cb_data *cb_hdr = skb_push(skb, sizeof(*cb_hdr));
+
+		cb_hdr->hdr.type = cpu_to_le16(SAP_MSG_CB_DATA_PACKET);
+		cb_hdr->hdr.len = cpu_to_le16(skb->len - sizeof(cb_hdr->hdr));
+		cb_hdr->hdr.seq_num = cpu_to_le32(atomic_inc_return(&mei->sap_seq_no));
+		cb_hdr->to_me_filt_status = cpu_to_le32(BIT(CB_TX_DHCP_FILT_IDX));
+		cb_hdr->data_len = cpu_to_le32(skb->len - sizeof(*cb_hdr));
+		trace_iwlmei_sap_data(skb, IWL_SAP_TX_DHCP);
+	} else {
+		struct iwl_sap_hdr *hdr = skb_push(skb, sizeof(*hdr));
+
+		hdr->type = cpu_to_le16(SAP_MSG_DATA_PACKET);
+		hdr->len = cpu_to_le16(skb->len - sizeof(*hdr));
+		hdr->seq_num = cpu_to_le32(atomic_inc_return(&mei->sap_seq_no));
+		trace_iwlmei_sap_data(skb, IWL_SAP_TX_DATA_FROM_AIR);
+	}
+
+	if (wr + tx_sz <= q_sz) {
+		skb_copy_bits(skb, 0, q_head + wr, tx_sz);
+	} else {
+		skb_copy_bits(skb, 0, q_head + wr, q_sz - wr);
+		skb_copy_bits(skb, q_sz - wr, q_head, tx_sz - (q_sz - wr));
+	}
+
+	WRITE_ONCE(notif_q->wr_ptr, cpu_to_le32((wr + tx_sz) % q_sz));
+
+out:
+	spin_unlock_bh(&mei->data_q_lock);
+}
+
+static int
+iwl_mei_send_sap_msg(struct mei_cl_device *cldev, u16 type)
+{
+	struct iwl_sap_hdr msg = {
+		.type = cpu_to_le16(type),
+	};
+
+	return iwl_mei_send_sap_msg_payload(cldev, &msg);
+}
+
+static void iwl_mei_send_csa_msg_wk(struct work_struct *wk)
+{
+	struct iwl_mei *mei =
+		container_of(wk, struct iwl_mei, send_csa_msg_wk);
+
+	if (!iwl_mei_is_connected()) {
+		IWL_MEI_ERR(mei->cldev,
+			    "Can't send SAP_ME_MSG_CHECK_SHARED_AREA, not connected\n");
+		return;
+	}
+
+	mutex_lock(&iwl_mei_mutex);
+
+	WARN_ON_ONCE(iwl_mei_send_check_shared_area(mei->cldev));
+
+	mutex_unlock(&iwl_mei_mutex);
+}
+
+/* Called in a RCU read critical section from netif_receive_skb */
+static rx_handler_result_t iwl_mei_rx_handler(struct sk_buff **pskb)
+{
+	struct sk_buff *skb = *pskb;
+	struct iwl_mei *mei =
+		rcu_dereference(skb->dev->rx_handler_data);
+	struct iwl_mei_filters *filters = rcu_dereference(mei->filters);
+	bool rx_for_csme = false;
+	rx_handler_result_t res;
+
+	/*
+	 * remove() unregisters this handler and synchronize_net, so this
+	 * should never happen.
+	 */
+	if (WARN_ON_ONCE(!iwl_mei_is_connected()))
+		return RX_HANDLER_PASS;
+
+	if (filters)
+		res = iwl_mei_rx_filter(skb, &filters->filters, &rx_for_csme);
+	else
+		res = RX_HANDLER_PASS;
+
+	/*
+	 * The data is already on the ring of the shared area, all we
+	 * need to do is to tell the CSME firmware to check what we have
+	 * there.
+	 */
+	if (rx_for_csme)
+		schedule_work(&mei->send_csa_msg_wk);
+
+	if (res != RX_HANDLER_PASS) {
+		trace_iwlmei_sap_data(skb, IWL_SAP_RX_DATA_DROPPED_FROM_AIR);
+		dev_kfree_skb(skb);
+	}
+
+	return res;
+}
+
+static void
+iwl_mei_handle_rx_start_ok(struct mei_cl_device *cldev,
+			   const struct iwl_sap_me_msg_start_ok *rsp,
+			   ssize_t len)
+{
+	struct iwl_mei *mei = mei_cldev_get_drvdata(cldev);
+
+	if (len != sizeof(*rsp)) {
+		IWL_MEI_ERR(cldev,
+			    "got invalid SAP_ME_MSG_START_OK from CSME firmware\n");
+		IWL_MEI_ERR(cldev,
+			    "size is incorrect: %ld instead of %lu\n",
+			    len, sizeof(*rsp));
+		return;
+	}
+
+	if (rsp->supported_version != SAP_VERSION) {
+		IWL_MEI_ERR(cldev,
+			    "didn't get the expected version: got %d\n",
+			    rsp->supported_version);
+		return;
+	}
+
+	IWL_MEI_INFO(cldev,
+		     "Got a valid SAP_ME_MSG_START_OK from CSME firmware\n");
+
+	mutex_lock(&iwl_mei_mutex);
+	set_bit(IWL_MEI_STATUS_SAP_CONNECTED, &iwl_mei_status);
+	/* wifi driver has registered already */
+	if (iwl_mei_cache.ops) {
+		WARN_ON(iwl_mei_send_sap_msg(mei->cldev,
+					     SAP_MSG_NOTIF_WIFIDR_UP));
+		iwl_mei_cache.ops->sap_connected(iwl_mei_cache.priv);
+	}
+
+	mutex_unlock(&iwl_mei_mutex);
+}
+
+static void iwl_mei_handle_csme_filters(struct mei_cl_device *cldev,
+					const struct iwl_sap_csme_filters *filters)
+{
+	struct iwl_mei *mei = mei_cldev_get_drvdata(iwl_mei_global_cldev);
+	struct iwl_mei_filters *new_filters;
+	struct iwl_mei_filters *old_filters;
+
+	IWL_MEI_DEBUG(cldev, "Got CSME filters\n");
+
+	old_filters =
+		rcu_dereference_protected(mei->filters,
+					  lockdep_is_held(&iwl_mei_mutex));
+
+	new_filters = kzalloc(sizeof(*new_filters), GFP_KERNEL);
+
+	/* Copy the OOB filters */
+	new_filters->filters = filters->filters;
+
+	rcu_assign_pointer(mei->filters, new_filters);
+
+	if (old_filters)
+		kfree_rcu(old_filters, rcu_head);
+}
+
+static void
+iwl_mei_handle_conn_status(struct mei_cl_device *cldev,
+			   const struct iwl_sap_notif_conn_status *status)
+{
+	struct iwl_mei *mei = mei_cldev_get_drvdata(cldev);
+	struct iwl_mei_conn_info conn_info = {
+		.lp_state = le32_to_cpu(status->link_prot_state),
+		.ssid_len = le32_to_cpu(status->conn_info.ssid_len),
+		.channel = status->conn_info.channel,
+		.band = status->conn_info.band,
+		.auth_mode = le32_to_cpu(status->conn_info.auth_mode),
+		.ucast_cipher = le32_to_cpu(status->conn_info.ucast_cipher),
+	};
+
+	IWL_MEI_DEBUG(cldev,
+		      "Got connection status: Link Protection Status: %d\n",
+		      !!status->link_prot_state);
+
+	if (!iwl_mei_cache.ops ||
+	    conn_info.ssid_len > ARRAY_SIZE(conn_info.ssid))
+		return;
+
+	memcpy(conn_info.ssid, status->conn_info.ssid, conn_info.ssid_len);
+	ether_addr_copy(conn_info.bssid, status->conn_info.bssid);
+
+	iwl_mei_cache.ops->me_conn_status(iwl_mei_cache.priv, &conn_info);
+
+	/*
+	 * Update the Rfkill state in case the host does not own the device:
+	 * if we are in Link Protection, ask to not touch the device, else,
+	 * unblock rfkill.
+	 * If the host owns the device, inform the user space whether it can
+	 * roam.
+	 */
+	if (mei->got_ownership)
+		iwl_mei_cache.ops->roaming_forbidden(iwl_mei_cache.priv,
+						     status->link_prot_state);
+	else
+		iwl_mei_cache.ops->rfkill(iwl_mei_cache.priv,
+					  status->link_prot_state);
+}
+
+static void iwl_mei_set_init_conf(struct iwl_mei *mei)
+{
+	struct iwl_sap_notif_host_link_up link_msg = {
+		.hdr.type = cpu_to_le16(SAP_MSG_NOTIF_HOST_LINK_UP),
+		.hdr.len = cpu_to_le16(sizeof(link_msg) - sizeof(link_msg.hdr)),
+	};
+	struct iwl_sap_notif_country_code mcc_msg = {
+		.hdr.type = cpu_to_le16(SAP_MSG_NOTIF_COUNTRY_CODE),
+		.hdr.len = cpu_to_le16(sizeof(mcc_msg) - sizeof(mcc_msg.hdr)),
+		.mcc = cpu_to_le16(iwl_mei_cache.mcc),
+	};
+	struct iwl_sap_notif_sar_limits sar_msg = {
+		.hdr.type = cpu_to_le16(SAP_MSG_NOTIF_SAR_LIMITS),
+		.hdr.len = cpu_to_le16(sizeof(sar_msg) - sizeof(sar_msg.hdr)),
+	};
+	struct iwl_sap_notif_host_nic_info nic_info_msg = {
+		.hdr.type = cpu_to_le16(SAP_MSG_NOTIF_NIC_INFO),
+		.hdr.len = cpu_to_le16(sizeof(nic_info_msg) - sizeof(nic_info_msg.hdr)),
+	};
+	struct iwl_sap_msg_dw rfkill_msg = {
+		.hdr.type = cpu_to_le16(SAP_MSG_NOTIF_RADIO_STATE),
+		.hdr.len = cpu_to_le16(sizeof(rfkill_msg) - sizeof(rfkill_msg.hdr)),
+		.val = cpu_to_le32(iwl_mei_cache.rf_kill),
+	};
+
+	iwl_mei_send_sap_msg(mei->cldev,
+			     SAP_MSG_NOTIF_HOST_ASKS_FOR_NIC_OWNERSHIP);
+
+	if (iwl_mei_cache.conn_info) {
+		link_msg.conn_info = *iwl_mei_cache.conn_info;
+		iwl_mei_send_sap_msg_payload(mei->cldev, &link_msg.hdr);
+	}
+
+	iwl_mei_send_sap_msg_payload(mei->cldev, &mcc_msg.hdr);
+
+	if (iwl_mei_cache.power_limit) {
+		memcpy(sar_msg.sar_chain_info_table, iwl_mei_cache.power_limit,
+		       sizeof(sar_msg.sar_chain_info_table));
+		iwl_mei_send_sap_msg_payload(mei->cldev, &sar_msg.hdr);
+	}
+
+	ether_addr_copy(nic_info_msg.mac_address, iwl_mei_cache.mac_address);
+	ether_addr_copy(nic_info_msg.nvm_address, iwl_mei_cache.nvm_address);
+	iwl_mei_send_sap_msg_payload(mei->cldev, &nic_info_msg.hdr);
+
+	iwl_mei_send_sap_msg_payload(mei->cldev, &rfkill_msg.hdr);
+}
+
+static void iwl_mei_handle_amt_state(struct mei_cl_device *cldev,
+				     const struct iwl_sap_msg_dw *dw)
+{
+	struct iwl_mei *mei = mei_cldev_get_drvdata(cldev);
+	struct net_device *netdev;
+
+	IWL_MEI_DEBUG(cldev, "Got AMT state: %d (was %d)\n",
+		      le32_to_cpu(dw->val), mei->amt_enabled);
+
+	/*
+	 * First take rtnl and only then the mutex to avoid an ABBA
+	 * with iwl_mei_set_netdev()
+	 */
+	rtnl_lock();
+	mutex_lock(&iwl_mei_mutex);
+
+	netdev = rcu_dereference_protected(iwl_mei_cache.netdev,
+					   lockdep_is_held(&iwl_mei_mutex));
+
+	if (mei->amt_enabled == !!le32_to_cpu(dw->val))
+		goto out;
+
+	mei->amt_enabled = dw->val;
+
+	if (mei->amt_enabled) {
+		if (netdev)
+			netdev_rx_handler_register(netdev, iwl_mei_rx_handler, mei);
+
+		iwl_mei_set_init_conf(mei);
+	} else {
+		if (iwl_mei_cache.ops)
+			iwl_mei_cache.ops->rfkill(iwl_mei_cache.priv, false);
+		if (netdev)
+			netdev_rx_handler_unregister(netdev);
+	}
+
+out:
+	mutex_unlock(&iwl_mei_mutex);
+	rtnl_unlock();
+}
+
+static void iwl_mei_handle_nic_owner(struct mei_cl_device *cldev,
+				     const struct iwl_sap_msg_dw *dw)
+{
+	IWL_MEI_DEBUG(cldev, "Got NIC owner: %s is owner\n",
+		      dw->val == cpu_to_le32(SAP_NIC_OWNER_ME) ? "me" : "host");
+}
+
+static void iwl_mei_handle_can_release_ownership(struct mei_cl_device *cldev,
+						 const void *payload)
+{
+	IWL_MEI_DEBUG(cldev, "Got Can release ownership\n");
+
+	/* We can get ownership and driver is registered, go ahead */
+	if (iwl_mei_cache.ops)
+		iwl_mei_send_sap_msg(cldev,
+				     SAP_MSG_NOTIF_HOST_ASKS_FOR_NIC_OWNERSHIP);
+}
+
+static void iwl_mei_handle_csme_taking_ownership(struct mei_cl_device *cldev,
+						 const void *payload)
+{
+	struct iwl_mei *mei = mei_cldev_get_drvdata(cldev);
+
+	IWL_MEI_INFO(cldev, "CSME takes ownership\n");
+
+	mei->got_ownership = false;
+
+	/*
+	 * Remember to send CSME_OWNERSHIP_CONFIRMED when the wifi driver
+	 * is finished taking the device down.
+	 */
+	mei->csme_taking_ownership = true;
+
+	if (iwl_mei_cache.ops)
+		iwl_mei_cache.ops->rfkill(iwl_mei_cache.priv, true);
+}
+
+static void iwl_mei_handle_nvm(struct mei_cl_device *cldev,
+			       const struct iwl_sap_nvm *sap_nvm)
+{
+	struct iwl_mei *mei = mei_cldev_get_drvdata(cldev);
+	const struct iwl_mei_nvm *mei_nvm = (const void *)sap_nvm;
+	int i;
+
+	IWL_MEI_DEBUG(cldev, "Got NVM data\n");
+
+	kfree(mei->nvm);
+	mei->nvm = kzalloc(sizeof(*mei_nvm), GFP_KERNEL);
+	if (!mei->nvm)
+		return;
+
+	ether_addr_copy(mei->nvm->hw_addr, sap_nvm->hw_addr);
+	mei->nvm->n_hw_addrs = sap_nvm->n_hw_addrs;
+	mei->nvm->radio_cfg = le32_to_cpu(sap_nvm->radio_cfg);
+	mei->nvm->caps = le32_to_cpu(sap_nvm->caps);
+	mei->nvm->nvm_version = le32_to_cpu(sap_nvm->nvm_version);
+
+	for (i = 0; i < ARRAY_SIZE(mei->nvm->channels); i++)
+		mei->nvm->channels[i] = le32_to_cpu(sap_nvm->channels[i]);
+
+	wake_up_all(&mei->get_nvm_wq);
+}
+
+static void iwl_mei_handle_rx_host_own_req(struct mei_cl_device *cldev,
+					   const struct iwl_sap_msg_dw *dw)
+{
+	struct iwl_mei *mei = mei_cldev_get_drvdata(cldev);
+
+	IWL_MEI_DEBUG(cldev, "Got ownership req response: %d\n", dw->val);
+
+	if (!dw->val) {
+		IWL_MEI_INFO(cldev, "Ownership req denied\n");
+		return;
+	}
+
+	mei->got_ownership = true;
+	wake_up_all(&mei->get_ownership_wq);
+
+	iwl_mei_send_sap_msg(cldev,
+			     SAP_MSG_NOTIF_HOST_OWNERSHIP_CONFIRMED);
+
+	/* We can now start the connection, unblock rfkill */
+	if (iwl_mei_cache.ops)
+		iwl_mei_cache.ops->rfkill(iwl_mei_cache.priv, false);
+}
+
+static void iwl_mei_handle_pong(struct mei_cl_device *cldev,
+				const void *payload)
+{
+#if IS_ENABLED(CONFIG_DEBUG_FS)
+	struct iwl_mei *mei = mei_cldev_get_drvdata(cldev);
+
+	mei->ping_pending = false;
+	wake_up_interruptible_all(&mei->debugfs_wq);
+#endif
+
+	IWL_MEI_DEBUG(cldev, "Got PONG\n");
+}
+
+static void iwl_mei_handle_ping(struct mei_cl_device *cldev,
+				const struct iwl_sap_hdr *hdr)
+{
+	iwl_mei_send_sap_msg(cldev, SAP_MSG_NOTIF_PONG);
+}
+
+static void iwl_mei_handle_sap_msg(struct mei_cl_device *cldev,
+				   const struct iwl_sap_hdr *hdr)
+{
+	u16 len = le16_to_cpu(hdr->len) + sizeof(*hdr);
+	u16 type = le16_to_cpu(hdr->type);
+
+	IWL_MEI_DEBUG(cldev, "Got a new SAP message: type %d, len %d, seq %d\n",
+		      le16_to_cpu(hdr->type), len,
+		      le32_to_cpu(hdr->seq_num));
+
+#define SAP_MSG_HANDLER(_cmd, _handler, _sz)				\
+	case SAP_MSG_NOTIF_ ## _cmd:					\
+		if (!WARN_ONCE(len < _sz, "%u < %u",			\
+			       (unsigned int)len, (unsigned int)_sz))	\
+			mutex_lock(&iwl_mei_mutex);			\
+			_handler(cldev, (const void *)hdr);		\
+			mutex_unlock(&iwl_mei_mutex);			\
+		break
+
+#define SAP_MSG_HANDLER_NO_LOCK(_cmd, _handler, _sz)			\
+	case SAP_MSG_NOTIF_ ## _cmd:					\
+		if (!WARN_ONCE(len < _sz, "%u < %u",			\
+			       (unsigned int)len, (unsigned int)_sz))	\
+			_handler(cldev, (const void *)hdr);		\
+		break
+
+	switch (type) {
+	SAP_MSG_HANDLER(PING, iwl_mei_handle_ping, 0);
+	SAP_MSG_HANDLER(CSME_FILTERS,
+			iwl_mei_handle_csme_filters,
+			sizeof(struct iwl_sap_csme_filters));
+	SAP_MSG_HANDLER(CSME_CONN_STATUS,
+			iwl_mei_handle_conn_status,
+			sizeof(struct iwl_sap_notif_conn_status));
+	SAP_MSG_HANDLER_NO_LOCK(AMT_STATE,
+				iwl_mei_handle_amt_state,
+				sizeof(struct iwl_sap_msg_dw));
+	SAP_MSG_HANDLER(PONG, iwl_mei_handle_pong, 0);
+	SAP_MSG_HANDLER(NVM, iwl_mei_handle_nvm,
+			sizeof(struct iwl_sap_nvm));
+	SAP_MSG_HANDLER(CSME_REPLY_TO_HOST_OWNERSHIP_REQ,
+			iwl_mei_handle_rx_host_own_req,
+			sizeof(struct iwl_sap_msg_dw));
+	SAP_MSG_HANDLER(NIC_OWNER, iwl_mei_handle_nic_owner,
+			sizeof(struct iwl_sap_msg_dw));
+	SAP_MSG_HANDLER(CSME_CAN_RELEASE_OWNERSHIP,
+			iwl_mei_handle_can_release_ownership, 0);
+	SAP_MSG_HANDLER(CSME_TAKING_OWNERSHIP,
+			iwl_mei_handle_csme_taking_ownership, 0);
+	default:
+	IWL_MEI_DEBUG(cldev, "Unsupported message: type %d, len %d\n",
+		      le16_to_cpu(hdr->type), len);
+	}
+
+#undef SAP_MSG_HANDLER
+}
+
+static void iwl_mei_read_from_q(const u8 *q_head, u32 q_sz,
+				u32 *_rd, u32 wr,
+				void *_buf, u32 len)
+{
+	u8 *buf = _buf;
+	u32 rd = *_rd;
+
+	if (rd + len <= q_sz) {
+		memcpy(buf, q_head + rd, len);
+		rd += len;
+	} else {
+		memcpy(buf, q_head + rd, q_sz - rd);
+		memcpy(buf + q_sz - rd, q_head, len - (q_sz - rd));
+		rd = len - (q_sz - rd);
+	}
+
+	*_rd = rd;
+}
+
+static void iwl_mei_handle_sap_data(struct mei_cl_device *cldev,
+				    const u8 *q_head, u32 q_sz,
+				    u32 rd, u32 wr, ssize_t valid_rx_sz,
+				    struct sk_buff_head *tx_skbs)
+{
+	struct iwl_sap_hdr hdr;
+	struct net_device *netdev =
+		rcu_dereference_protected(iwl_mei_cache.netdev,
+					  lockdep_is_held(&iwl_mei_mutex));
+
+	if (!netdev) {
+		IWL_MEI_INFO(cldev, "No netdevice, dropping the Tx packet\n");
+		return;
+	}
+
+	while (valid_rx_sz >= sizeof(hdr)) {
+		struct ethhdr *ethhdr;
+		unsigned char *data;
+		struct sk_buff *skb;
+		u16 len;
+
+		iwl_mei_read_from_q(q_head, q_sz, &rd, wr, &hdr, sizeof(hdr));
+		valid_rx_sz -= sizeof(hdr);
+		len = le16_to_cpu(hdr.len);
+
+		if (valid_rx_sz < len) {
+			IWL_MEI_ERR(cldev,
+				    "Data queue is corrupted: valid data len %ld, len %d\n",
+				    valid_rx_sz, len);
+			break;
+		}
+
+		if (len < sizeof(*ethhdr)) {
+			IWL_MEI_ERR(cldev,
+				    "Data len is smaller than an ethernet header? len = %d\n",
+				    len);
+		}
+
+		valid_rx_sz -= len;
+
+		if (le16_to_cpu(hdr.type) != SAP_MSG_DATA_PACKET) {
+			IWL_MEI_INFO(cldev, "Unsupported message: type %d, len %d\n",
+				     le16_to_cpu(hdr.type), len);
+			continue;
+		}
+
+		/* We need enough room for the WiFi header + SNAP + IV */
+		skb = netdev_alloc_skb(netdev, len + 26 + 8 + 8);
+
+		skb_reserve(skb, 26 + 8 + 8);
+		ethhdr = skb_push(skb, sizeof(*ethhdr));
+
+		iwl_mei_read_from_q(q_head, q_sz, &rd, wr,
+				    ethhdr, sizeof(*ethhdr));
+		len -= sizeof(*ethhdr);
+
+		skb_reset_mac_header(skb);
+		skb_reset_network_header(skb);
+		skb->protocol = ethhdr->h_proto;
+
+		/* we don't really want to get anything besides 802.3 packets */
+		WARN_ON_ONCE(!eth_proto_is_802_3(ethhdr->h_proto));
+
+		data = skb_put(skb, len);
+		iwl_mei_read_from_q(q_head, q_sz, &rd, wr, data, len);
+
+		/*
+		 * Enqueue the skb here so that it can be sent later when we
+		 * do not hold the mutex. TX'ing a packet with a mutex held is
+		 * possible, but it wouldn't be nice to forbid the TX path to
+		 * call any of iwlmei's functions, since every API from iwlmei
+		 * needs the mutex.
+		 */
+		__skb_queue_tail(tx_skbs, skb);
+	}
+}
+
+static void iwl_mei_handle_sap_rx_cmd(struct mei_cl_device *cldev,
+				      const u8 *q_head, u32 q_sz,
+				      u32 rd, u32 wr, ssize_t valid_rx_sz)
+{
+	struct page *p = alloc_page(GFP_KERNEL);
+	struct iwl_sap_hdr *hdr;
+
+	if (!p)
+		return;
+
+	hdr = page_address(p);
+
+	while (valid_rx_sz >= sizeof(*hdr)) {
+		u16 len;
+
+		iwl_mei_read_from_q(q_head, q_sz, &rd, wr, hdr, sizeof(*hdr));
+		valid_rx_sz -= sizeof(*hdr);
+		len = le16_to_cpu(hdr->len);
+
+		if (valid_rx_sz < len)
+			break;
+
+		iwl_mei_read_from_q(q_head, q_sz, &rd, wr, hdr + 1, len);
+
+		trace_iwlmei_sap_cmd(hdr, false);
+		iwl_mei_handle_sap_msg(cldev, hdr);
+		valid_rx_sz -= len;
+	}
+
+	/* valid_rx_sz must be 0 now... */
+	WARN_ON_ONCE(valid_rx_sz);
+
+	__free_page(p);
+}
+
+static void iwl_mei_handle_sap_rx(struct mei_cl_device *cldev,
+				  struct iwl_sap_q_ctrl_blk *notif_q,
+				  const u8 *q_head,
+				  struct sk_buff_head *skbs)
+{
+	u32 rd = le32_to_cpu(READ_ONCE(notif_q->rd_ptr));
+	u32 wr = le32_to_cpu(READ_ONCE(notif_q->wr_ptr));
+	u32 q_sz = le32_to_cpu(notif_q->size);
+	ssize_t valid_rx_sz;
+
+	if (WARN_ON_ONCE(rd > q_sz || wr > q_sz))
+		return;
+
+	if (rd == wr)
+		return;
+
+	valid_rx_sz = wr > rd ? wr - rd : q_sz - rd + wr;
+
+	if (skbs)
+		iwl_mei_handle_sap_data(cldev, q_head, q_sz, rd, wr,
+					valid_rx_sz, skbs);
+	else
+		iwl_mei_handle_sap_rx_cmd(cldev, q_head, q_sz, rd, wr,
+					  valid_rx_sz);
+
+	/* Increment the read pointer to point to the write pointer */
+	WRITE_ONCE(notif_q->rd_ptr, cpu_to_le32(wr));
+}
+
+static void iwl_mei_handle_check_shared_area(struct mei_cl_device *cldev)
+{
+	struct iwl_mei *mei = mei_cldev_get_drvdata(cldev);
+	struct iwl_sap_q_ctrl_blk *notif_q;
+	struct sk_buff_head tx_skbs;
+	struct iwl_sap_dir *dir;
+	void *q_head;
+
+	if (WARN_ON(!mei->shared_mem.ctrl))
+		return;
+
+	dir = &mei->shared_mem.ctrl->dir[SAP_DIRECTION_ME_TO_HOST];
+	notif_q = &dir->q_ctrl_blk[SAP_QUEUE_IDX_NOTIF];
+	q_head = mei->shared_mem.q_head[SAP_DIRECTION_ME_TO_HOST][SAP_QUEUE_IDX_NOTIF];
+
+	/*
+	 * Do not hold the mutex here, but rather each and every message
+	 * handler takes it.
+	 * This allows message handlers to take it at a certain time.
+	 */
+	iwl_mei_handle_sap_rx(cldev, notif_q, q_head, NULL);
+
+	mutex_lock(&iwl_mei_mutex);
+	dir = &mei->shared_mem.ctrl->dir[SAP_DIRECTION_ME_TO_HOST];
+	notif_q = &dir->q_ctrl_blk[SAP_QUEUE_IDX_DATA];
+	q_head = mei->shared_mem.q_head[SAP_DIRECTION_ME_TO_HOST][SAP_QUEUE_IDX_DATA];
+
+	__skb_queue_head_init(&tx_skbs);
+
+	iwl_mei_handle_sap_rx(cldev, notif_q, q_head, &tx_skbs);
+
+	if (skb_queue_empty(&tx_skbs)) {
+		mutex_unlock(&iwl_mei_mutex);
+		return;
+	}
+
+	/*
+	 * Take the RCU read lock before we unlock the mutex to make sure that
+	 * even if the netdev is replaced by another non-NULL netdev right after
+	 * we unlock the mutex, the old netdev will still be valid when we
+	 * transmit the frames. We can't allow to replace the netdev here because
+	 * the skbs hold a pointer to the netdev.
+	 */
+	rcu_read_lock();
+
+	mutex_unlock(&iwl_mei_mutex);
+
+	if (!rcu_access_pointer(iwl_mei_cache.netdev)) {
+		IWL_MEI_ERR(cldev, "Can't Tx without a netdev\n");
+		skb_queue_purge(&tx_skbs);
+		goto out;
+	}
+
+	while (!skb_queue_empty(&tx_skbs)) {
+		struct sk_buff *skb = __skb_dequeue(&tx_skbs);
+
+		trace_iwlmei_sap_data(skb, IWL_SAP_RX_DATA_TO_AIR);
+		dev_queue_xmit(skb);
+	}
+
+out:
+	rcu_read_unlock();
+}
+
+static void iwl_mei_rx(struct mei_cl_device *cldev)
+{
+	struct iwl_sap_me_msg_hdr *hdr;
+	u8 msg[100];
+	ssize_t ret;
+
+	ret = mei_cldev_recv(cldev, (u8 *)&msg, sizeof(msg));
+	if (ret < 0) {
+		IWL_MEI_ERR(cldev, "failed to receive data: %ld\n", ret);
+		return;
+	}
+
+	if (ret == 0) {
+		IWL_MEI_ERR(cldev, "got an empty response\n");
+		return;
+	}
+
+	hdr = (void *)msg;
+	trace_iwlmei_me_msg(hdr, false);
+
+	switch (le32_to_cpu(hdr->type)) {
+	case SAP_ME_MSG_START_OK:
+		BUILD_BUG_ON(sizeof(struct iwl_sap_me_msg_start_ok) >
+			     sizeof(msg));
+
+		iwl_mei_handle_rx_start_ok(cldev, (void *)msg, ret);
+		break;
+	case SAP_ME_MSG_CHECK_SHARED_AREA:
+		iwl_mei_handle_check_shared_area(cldev);
+		break;
+	default:
+		IWL_MEI_INFO(cldev, "got a RX message: %d\n",
+			     le32_to_cpu(hdr->type));
+		break;
+	}
+}
+
+static int iwl_mei_send_start(struct mei_cl_device *cldev)
+{
+	struct iwl_mei *mei = mei_cldev_get_drvdata(cldev);
+	struct iwl_sap_me_msg_start msg = {
+		.hdr.type = cpu_to_le32(SAP_ME_MSG_START),
+		.hdr.seq_num = cpu_to_le32(atomic_inc_return(&mei->seq_no)),
+		.hdr.len = cpu_to_le32(sizeof(msg)),
+		.supported_versions[0] = SAP_VERSION,
+		.init_data_seq_num = cpu_to_le16(0x100),
+		.init_notif_seq_num = cpu_to_le16(0x800),
+	};
+	int ret;
+
+	trace_iwlmei_me_msg(&msg.hdr, true);
+	ret = mei_cldev_send(cldev, (void *)&msg, sizeof(msg));
+	if (ret != sizeof(msg)) {
+		IWL_MEI_ERR(cldev,
+			    "failed to send the SAP_ME_MSG_START message %d\n",
+			    ret);
+		return ret;
+	}
+
+	IWL_MEI_DEBUG(cldev,
+		      "SAP_ME_MSG_START sent, waiting for the response...\n");
+
+	return 0;
+}
+
+static int iwl_mei_enable(struct mei_cl_device *cldev)
+{
+	int ret;
+
+	ret = mei_cldev_enable(cldev);
+	if (ret < 0) {
+		IWL_MEI_ERR(cldev, "failed to enable the device: %d\n", ret);
+		return ret;
+	}
+
+	ret = mei_cldev_register_rx_cb(cldev, iwl_mei_rx);
+	if (ret) {
+		IWL_MEI_ERR(cldev,
+			    "failed to register to the rx cb: %d\n", ret);
+		WARN_ON(mei_cldev_disable(cldev));
+		return ret;
+	}
+
+	return 0;
+}
+
+struct iwl_mei_nvm *iwl_mei_get_nvm(void)
+{
+	struct iwl_mei_nvm *nvm = NULL;
+	struct iwl_mei *mei;
+	int ret;
+
+	mutex_lock(&iwl_mei_mutex);
+
+	if (!iwl_mei_is_connected())
+		goto out;
+
+	mei = mei_cldev_get_drvdata(iwl_mei_global_cldev);
+
+	if (WARN_ON(!mei))
+		goto out;
+
+	ret = iwl_mei_send_sap_msg(iwl_mei_global_cldev,
+				   SAP_MSG_NOTIF_GET_NVM);
+	if (ret)
+		goto out;
+
+	mutex_unlock(&iwl_mei_mutex);
+
+	ret = wait_event_timeout(mei->get_nvm_wq, mei->nvm, 2 * HZ);
+	if (!ret)
+		return NULL;
+
+	mutex_lock(&iwl_mei_mutex);
+
+	if (!iwl_mei_is_connected())
+		goto out;
+
+	mei = mei_cldev_get_drvdata(iwl_mei_global_cldev);
+
+	if (WARN_ON(!mei))
+		goto out;
+
+	if (mei->nvm)
+		nvm = kmemdup(mei->nvm, sizeof(*mei->nvm), GFP_KERNEL);
+
+out:
+	mutex_unlock(&iwl_mei_mutex);
+	return nvm;
+}
+EXPORT_SYMBOL(iwl_mei_get_nvm);
+
+int iwl_mei_get_ownership(void)
+{
+	struct iwl_mei *mei;
+	int ret;
+
+	mutex_lock(&iwl_mei_mutex);
+
+	/* In case we didn't have a bind */
+	if (!iwl_mei_is_connected()) {
+		ret = 0;
+		goto out;
+	}
+
+	mei = mei_cldev_get_drvdata(iwl_mei_global_cldev);
+
+	if (WARN_ON(!mei)) {
+		ret = -ENODEV;
+		goto out;
+	}
+
+	if (!mei->amt_enabled) {
+		ret = 0;
+		goto out;
+	}
+
+	mei->got_ownership = false;
+
+	ret = iwl_mei_send_sap_msg(mei->cldev,
+				   SAP_MSG_NOTIF_HOST_ASKS_FOR_NIC_OWNERSHIP);
+	if (ret)
+		goto out;
+
+	mutex_unlock(&iwl_mei_mutex);
+
+	ret = wait_event_timeout(mei->get_ownership_wq,
+				 mei->got_ownership, HZ / 2);
+	if (!ret)
+		return -ETIMEDOUT;
+
+	mutex_lock(&iwl_mei_mutex);
+
+	/* In case we didn't have a bind */
+	if (!iwl_mei_is_connected()) {
+		ret = 0;
+		goto out;
+	}
+
+	mei = mei_cldev_get_drvdata(iwl_mei_global_cldev);
+
+	if (WARN_ON(!mei)) {
+		ret = -ENODEV;
+		goto out;
+	}
+
+	ret = !mei->got_ownership;
+
+out:
+	mutex_unlock(&iwl_mei_mutex);
+	return ret;
+}
+EXPORT_SYMBOL(iwl_mei_get_ownership);
+
+void iwl_mei_host_associated(const struct iwl_mei_conn_info *conn_info,
+			     const struct iwl_mei_colloc_info *colloc_info)
+{
+	struct iwl_sap_notif_host_link_up msg = {
+		.hdr.type = cpu_to_le16(SAP_MSG_NOTIF_HOST_LINK_UP),
+		.hdr.len = cpu_to_le16(sizeof(msg) - sizeof(msg.hdr)),
+		.conn_info = {
+			.ssid_len = cpu_to_le32(conn_info->ssid_len),
+			.channel = conn_info->channel,
+			.band = conn_info->band,
+			.ucast_cipher = cpu_to_le32(conn_info->ucast_cipher),
+			.auth_mode = cpu_to_le32(conn_info->auth_mode),
+		},
+	};
+	struct iwl_mei *mei;
+
+	if (WARN_ON(conn_info->ssid_len > ARRAY_SIZE(msg.conn_info.ssid)))
+		return;
+
+	memcpy(msg.conn_info.ssid, conn_info->ssid, conn_info->ssid_len);
+	memcpy(msg.conn_info.bssid, conn_info->bssid, ETH_ALEN);
+
+	if (colloc_info) {
+		msg.colloc_channel = colloc_info->channel;
+		msg.colloc_band = colloc_info->channel <= 14 ? 0 : 1;
+		memcpy(msg.colloc_bssid, colloc_info->bssid, ETH_ALEN);
+	}
+
+	mutex_lock(&iwl_mei_mutex);
+
+	if (!iwl_mei_is_connected())
+		goto out;
+
+	mei = mei_cldev_get_drvdata(iwl_mei_global_cldev);
+
+	/* if mei is NULL, iwl_mei_global_cldev should have been NULL */
+	if (WARN_ON(!mei))
+		goto out;
+
+	if (!mei->amt_enabled)
+		goto out;
+
+	iwl_mei_send_sap_msg_payload(mei->cldev, &msg.hdr);
+
+out:
+	kfree(iwl_mei_cache.conn_info);
+	iwl_mei_cache.conn_info =
+		kmemdup(&msg.conn_info, sizeof(msg.conn_info), GFP_KERNEL);
+	mutex_unlock(&iwl_mei_mutex);
+}
+EXPORT_SYMBOL(iwl_mei_host_associated);
+
+void iwl_mei_host_disassociated(const u8 type)
+{
+	struct iwl_mei *mei;
+	struct iwl_sap_notif_host_link_down msg = {
+		.hdr.type = cpu_to_le16(SAP_MSG_NOTIF_HOST_LINK_DOWN),
+		.hdr.len = cpu_to_le16(sizeof(msg) - sizeof(msg.hdr)),
+		.type = type,
+	};
+
+	mutex_lock(&iwl_mei_mutex);
+
+	if (!iwl_mei_is_connected())
+		goto out;
+
+	mei = mei_cldev_get_drvdata(iwl_mei_global_cldev);
+
+	/* if mei is NULL, iwl_mei_global_cldev should have been NULL */
+	if (WARN_ON(!mei))
+		goto out;
+
+	iwl_mei_send_sap_msg_payload(mei->cldev, &msg.hdr);
+
+out:
+	kfree(iwl_mei_cache.conn_info);
+	iwl_mei_cache.conn_info = NULL;
+	mutex_unlock(&iwl_mei_mutex);
+}
+EXPORT_SYMBOL(iwl_mei_host_disassociated);
+
+void iwl_mei_set_rfkill_state(bool hw_rfkill, bool sw_rfkill)
+{
+	struct iwl_mei *mei;
+	u32 rfkill_state = 0;
+	struct iwl_sap_msg_dw msg = {
+		.hdr.type = cpu_to_le16(SAP_MSG_NOTIF_RADIO_STATE),
+		.hdr.len = cpu_to_le16(sizeof(msg) - sizeof(msg.hdr)),
+	};
+
+	if (!sw_rfkill)
+		rfkill_state |= SAP_SW_RFKILL_DEASSERTED;
+
+	if (!hw_rfkill)
+		rfkill_state |= SAP_HW_RFKILL_DEASSERTED;
+
+	mutex_lock(&iwl_mei_mutex);
+
+	if (!iwl_mei_is_connected())
+		goto out;
+
+	msg.val = cpu_to_le32(rfkill_state);
+
+	mei = mei_cldev_get_drvdata(iwl_mei_global_cldev);
+
+	/* if mei is NULL, iwl_mei_global_cldev should have been NULL */
+	if (WARN_ON(!mei))
+		goto out;
+
+	iwl_mei_send_sap_msg_payload(mei->cldev, &msg.hdr);
+
+out:
+	iwl_mei_cache.rf_kill = rfkill_state;
+	mutex_unlock(&iwl_mei_mutex);
+}
+EXPORT_SYMBOL(iwl_mei_set_rfkill_state);
+
+void iwl_mei_set_nic_info(const u8 *mac_address, const u8 *nvm_address)
+{
+	struct iwl_mei *mei;
+	struct iwl_sap_notif_host_nic_info msg = {
+		.hdr.type = cpu_to_le16(SAP_MSG_NOTIF_NIC_INFO),
+		.hdr.len = cpu_to_le16(sizeof(msg) - sizeof(msg.hdr)),
+	};
+
+	mutex_lock(&iwl_mei_mutex);
+
+	if (!iwl_mei_is_connected())
+		goto out;
+
+	ether_addr_copy(msg.mac_address, mac_address);
+	ether_addr_copy(msg.nvm_address, nvm_address);
+
+	mei = mei_cldev_get_drvdata(iwl_mei_global_cldev);
+
+	if (WARN_ON(!mei))
+		goto out;
+
+	iwl_mei_send_sap_msg_payload(mei->cldev, &msg.hdr);
+
+out:
+	ether_addr_copy(iwl_mei_cache.mac_address, mac_address);
+	ether_addr_copy(iwl_mei_cache.nvm_address, nvm_address);
+	mutex_unlock(&iwl_mei_mutex);
+}
+EXPORT_SYMBOL(iwl_mei_set_nic_info);
+
+void iwl_mei_set_country_code(u16 mcc)
+{
+	struct iwl_mei *mei;
+	struct iwl_sap_notif_country_code msg = {
+		.hdr.type = cpu_to_le16(SAP_MSG_NOTIF_COUNTRY_CODE),
+		.hdr.len = cpu_to_le16(sizeof(msg) - sizeof(msg.hdr)),
+		.mcc = cpu_to_le16(mcc),
+	};
+
+	mutex_lock(&iwl_mei_mutex);
+
+	if (!iwl_mei_is_connected())
+		goto out;
+
+	mei = mei_cldev_get_drvdata(iwl_mei_global_cldev);
+
+	if (WARN_ON(!mei))
+		goto out;
+
+	iwl_mei_send_sap_msg_payload(mei->cldev, &msg.hdr);
+
+out:
+	iwl_mei_cache.mcc = mcc;
+	mutex_unlock(&iwl_mei_mutex);
+}
+EXPORT_SYMBOL(iwl_mei_set_country_code);
+
+void iwl_mei_set_power_limit(const __le16 *power_limit)
+{
+	struct iwl_mei *mei;
+	struct iwl_sap_notif_sar_limits msg = {
+		.hdr.type = cpu_to_le16(SAP_MSG_NOTIF_SAR_LIMITS),
+		.hdr.len = cpu_to_le16(sizeof(msg) - sizeof(msg.hdr)),
+	};
+
+	mutex_lock(&iwl_mei_mutex);
+
+	if (!iwl_mei_is_connected())
+		goto out;
+
+	mei = mei_cldev_get_drvdata(iwl_mei_global_cldev);
+
+	if (WARN_ON(!mei))
+		goto out;
+
+	memcpy(msg.sar_chain_info_table, power_limit, sizeof(msg.sar_chain_info_table));
+
+	iwl_mei_send_sap_msg_payload(mei->cldev, &msg.hdr);
+
+out:
+	kfree(iwl_mei_cache.power_limit);
+	iwl_mei_cache.power_limit = kmemdup(power_limit,
+					    sizeof(msg.sar_chain_info_table), GFP_KERNEL);
+	mutex_unlock(&iwl_mei_mutex);
+}
+EXPORT_SYMBOL(iwl_mei_set_power_limit);
+
+void iwl_mei_set_netdev(struct net_device *netdev)
+{
+	struct iwl_mei *mei;
+
+	mutex_lock(&iwl_mei_mutex);
+
+	if (!iwl_mei_is_connected()) {
+		rcu_assign_pointer(iwl_mei_cache.netdev, netdev);
+		goto out;
+	}
+
+	mei = mei_cldev_get_drvdata(iwl_mei_global_cldev);
+
+	if (WARN_ON(!mei))
+		goto out;
+
+	if (!netdev) {
+		struct net_device *dev =
+			rcu_dereference_protected(iwl_mei_cache.netdev,
+						  lockdep_is_held(&iwl_mei_mutex));
+
+		if (!dev)
+			goto out;
+
+		netdev_rx_handler_unregister(dev);
+	}
+
+	rcu_assign_pointer(iwl_mei_cache.netdev, netdev);
+
+	if (netdev && mei->amt_enabled)
+		netdev_rx_handler_register(netdev, iwl_mei_rx_handler, mei);
+
+out:
+	mutex_unlock(&iwl_mei_mutex);
+}
+EXPORT_SYMBOL(iwl_mei_set_netdev);
+
+void iwl_mei_device_down(void)
+{
+	struct iwl_mei *mei;
+
+	mutex_lock(&iwl_mei_mutex);
+
+	if (!iwl_mei_is_connected())
+		goto out;
+
+	mei = mei_cldev_get_drvdata(iwl_mei_global_cldev);
+
+	if (WARN_ON(!mei))
+		goto out;
+
+	if (!mei->csme_taking_ownership)
+		goto out;
+
+	iwl_mei_send_sap_msg(mei->cldev,
+			     SAP_MSG_NOTIF_CSME_OWNERSHIP_CONFIRMED);
+	mei->csme_taking_ownership = false;
+out:
+	mutex_unlock(&iwl_mei_mutex);
+}
+EXPORT_SYMBOL(iwl_mei_device_down);
+
+int iwl_mei_register(void *priv, const struct iwl_mei_ops *ops)
+{
+	int ret;
+
+	/*
+	 * We must have a non-NULL priv pointer to not crash when there are
+	 * multiple WiFi devices.
+	 */
+	if (WARN_ON(!priv))
+		return -EINVAL;
+
+	mutex_lock(&iwl_mei_mutex);
+
+	/* do not allow registration if someone else already registered */
+	if (iwl_mei_cache.priv || iwl_mei_cache.ops) {
+		ret = -EBUSY;
+		goto out;
+	}
+
+	iwl_mei_cache.priv = priv;
+	iwl_mei_cache.ops = ops;
+
+	if (iwl_mei_global_cldev) {
+		struct iwl_mei *mei =
+			mei_cldev_get_drvdata(iwl_mei_global_cldev);
+
+		/* we have already a SAP connection */
+		if (iwl_mei_is_connected())
+			iwl_mei_send_sap_msg(mei->cldev,
+					     SAP_MSG_NOTIF_WIFIDR_UP);
+	}
+	ret = 0;
+
+out:
+	mutex_unlock(&iwl_mei_mutex);
+	return ret;
+}
+EXPORT_SYMBOL(iwl_mei_register);
+
+void iwl_mei_start_unregister(void)
+{
+	mutex_lock(&iwl_mei_mutex);
+
+	/* At this point, the wifi driver should have removed the netdev */
+	WARN_ON(rcu_access_pointer(iwl_mei_cache.netdev));
+
+	kfree(iwl_mei_cache.conn_info);
+	iwl_mei_cache.conn_info = NULL;
+	kfree(iwl_mei_cache.power_limit);
+	iwl_mei_cache.power_limit = NULL;
+	iwl_mei_cache.ops = NULL;
+	/* leave iwl_mei_cache.priv non-NULL to prevent any new registration */
+
+	mutex_unlock(&iwl_mei_mutex);
+}
+EXPORT_SYMBOL(iwl_mei_start_unregister);
+
+void iwl_mei_unregister_complete(void)
+{
+	mutex_lock(&iwl_mei_mutex);
+
+	iwl_mei_cache.priv = NULL;
+
+	if (iwl_mei_global_cldev) {
+		struct iwl_mei *mei =
+			mei_cldev_get_drvdata(iwl_mei_global_cldev);
+
+		iwl_mei_send_sap_msg(mei->cldev, SAP_MSG_NOTIF_WIFIDR_DOWN);
+	}
+
+	mutex_unlock(&iwl_mei_mutex);
+}
+EXPORT_SYMBOL(iwl_mei_unregister_complete);
+
+#if IS_ENABLED(CONFIG_DEBUG_FS)
+
+static int iwl_mei_dbgfs_ping_open(struct inode *inode, struct file *file)
+{
+	struct iwl_mei *mei = inode->i_private;
+	int ret;
+
+	file->private_data = inode->i_private;
+
+	mutex_lock(&iwl_mei_mutex);
+
+	mei->ping_pending = true;
+	ret = iwl_mei_send_sap_msg(mei->cldev, SAP_MSG_NOTIF_PING);
+
+	mutex_unlock(&iwl_mei_mutex);
+
+	return ret;
+}
+
+static ssize_t iwl_mei_dbgfs_ping_read(struct file *file, char __user *user_buf,
+				       size_t count, loff_t *ppos)
+{
+	struct iwl_mei *mei = file->private_data;
+	char buf[16];
+	int pos;
+	int ret = wait_event_interruptible_timeout(mei->debugfs_wq,
+						   !mei->ping_pending, HZ);
+
+	if (ret > 0)
+		pos = scnprintf(buf, sizeof(buf), "pong received\n");
+	else
+		pos = scnprintf(buf, sizeof(buf), "interrupted\n");
+
+	return simple_read_from_buffer(user_buf, count, ppos, buf, pos);
+}
+
+static const struct file_operations iwl_mei_dbgfs_ping_ops = {
+	.read = iwl_mei_dbgfs_ping_read,
+	.open = iwl_mei_dbgfs_ping_open,
+	.llseek = default_llseek,
+};
+
+static ssize_t
+iwl_mei_dbgfs_send_start_message_write(struct file *file,
+				       const char __user *user_buf,
+				       size_t count, loff_t *ppos)
+{
+	int ret;
+
+	mutex_lock(&iwl_mei_mutex);
+
+	if (!iwl_mei_global_cldev) {
+		ret = -ENODEV;
+		goto out;
+	}
+
+	ret = iwl_mei_send_start(iwl_mei_global_cldev);
+
+out:
+	mutex_unlock(&iwl_mei_mutex);
+	return ret ?: count;
+}
+
+static const struct file_operations iwl_mei_dbgfs_send_start_message_ops = {
+	.write = iwl_mei_dbgfs_send_start_message_write,
+	.open = simple_open,
+	.llseek = default_llseek,
+};
+
+static ssize_t iwl_mei_dbgfs_req_ownership_write(struct file *file,
+						 const char __user *user_buf,
+						 size_t count, loff_t *ppos)
+{
+	iwl_mei_get_ownership();
+
+	return count;
+}
+
+static const struct file_operations iwl_mei_dbgfs_req_ownership_ops = {
+	.write = iwl_mei_dbgfs_req_ownership_write,
+	.open = simple_open,
+	.llseek = default_llseek,
+};
+
+static void iwl_mei_dbgfs_register(struct iwl_mei *mei)
+{
+	mei->dbgfs_dir = debugfs_create_dir(KBUILD_MODNAME, NULL);
+
+	if (!mei->dbgfs_dir)
+		return;
+
+	init_waitqueue_head(&mei->debugfs_wq);
+
+	debugfs_create_ulong("status", S_IRUSR,
+			     mei->dbgfs_dir, &iwl_mei_status);
+	debugfs_create_file("ping", S_IRUSR, mei->dbgfs_dir,
+			    mei, &iwl_mei_dbgfs_ping_ops);
+	debugfs_create_file("send_start_message", S_IWUSR, mei->dbgfs_dir,
+			    mei, &iwl_mei_dbgfs_send_start_message_ops);
+	debugfs_create_file("req_ownserhip", S_IWUSR, mei->dbgfs_dir,
+			    mei, &iwl_mei_dbgfs_req_ownership_ops);
+}
+
+static void iwl_mei_dbgfs_unregister(struct iwl_mei *mei)
+{
+	debugfs_remove_recursive(mei->dbgfs_dir);
+	mei->dbgfs_dir = NULL;
+}
+
+#else
+
+static void iwl_mei_dbgfs_register(struct iwl_mei *mei) {}
+static void iwl_mei_dbgfs_unregister(struct iwl_mei *mei) {}
+
+#endif /* CONFIG_DEBUG_FS */
+
+/**
+ * iwl_mei_probe - the probe function called by the mei bus enumeration
+ *
+ * This allocates the data needed by iwlmei and sets a pointer to this data
+ * into the mei_cl_device's drvdata.
+ * It starts the SAP protocol by sending the SAP_ME_MSG_START without
+ * waiting for the answer. The answer will be caught later by the Rx callback.
+ */
+static int iwl_mei_probe(struct mei_cl_device *cldev,
+			 const struct mei_cl_device_id *id)
+{
+	struct iwl_mei *mei;
+	int ret;
+
+	mei = devm_kzalloc(&cldev->dev, sizeof(*mei), GFP_KERNEL);
+	if (!mei)
+		return -ENOMEM;
+
+	init_waitqueue_head(&mei->get_nvm_wq);
+	INIT_WORK(&mei->send_csa_msg_wk, iwl_mei_send_csa_msg_wk);
+	INIT_DELAYED_WORK(&mei->csa_throttle_end_wk,
+			  iwl_mei_csa_throttle_end_wk);
+	init_waitqueue_head(&mei->get_ownership_wq);
+	spin_lock_init(&mei->data_q_lock);
+
+	mei_cldev_set_drvdata(cldev, mei);
+	mei->cldev = cldev;
+
+	ret = iwl_mei_alloc_shared_mem(cldev);
+	if (ret)
+		goto free;
+
+	iwl_mei_init_shared_mem(mei);
+
+	ret = iwl_mei_enable(cldev);
+	if (ret)
+		goto free_shared_mem;
+
+	iwl_mei_dbgfs_register(mei);
+
+#if IS_ENABLED(CONFIG_DEBUG_FS)
+	/* Wait for the debugfs hook to start the SAP protocol */
+	if (defer_start_message) {
+		iwl_mei_global_cldev = cldev;
+		return 0;
+	}
+#endif
+
+	/*
+	 * We now have a Rx function in place, start the SAP procotol
+	 * we expect to get the SAP_ME_MSG_START_OK response later on.
+	 */
+	mutex_lock(&iwl_mei_mutex);
+	ret = iwl_mei_send_start(cldev);
+	mutex_unlock(&iwl_mei_mutex);
+	if (ret)
+		goto debugfs_unregister;
+
+	/* must be last */
+	iwl_mei_global_cldev = cldev;
+
+	return 0;
+
+debugfs_unregister:
+	iwl_mei_dbgfs_unregister(mei);
+	WARN_ON(mei_cldev_disable(cldev));
+free_shared_mem:
+	iwl_mei_free_shared_mem(cldev);
+free:
+	mei_cldev_set_drvdata(cldev, NULL);
+	devm_kfree(&cldev->dev, mei);
+
+	return ret;
+}
+
+static void iwl_mei_remove(struct mei_cl_device *cldev)
+{
+	struct iwl_mei *mei = mei_cldev_get_drvdata(cldev);
+	int i;
+
+	/*
+	 * We are being removed while the bus is active, it means we are
+	 * going to suspend/ shutdown, so the NIC will disappear.
+	 */
+	if (mei_cldev_enabled(cldev) && iwl_mei_cache.ops)
+		iwl_mei_cache.ops->nic_stolen(iwl_mei_cache.priv);
+
+	if (rcu_access_pointer(iwl_mei_cache.netdev)) {
+		struct net_device *dev;
+
+		/*
+		 * If we are suspending and the wifi driver hasn't removed it's netdev
+		 * yet, do it now. In any case, don't change the cache.netdev pointer.
+		 */
+		dev = rcu_dereference_protected(iwl_mei_cache.netdev,
+						lockdep_is_held(&iwl_mei_mutex));
+
+		rtnl_lock();
+		netdev_rx_handler_unregister(dev);
+		rtnl_unlock();
+	}
+
+	mutex_lock(&iwl_mei_mutex);
+
+	/*
+	 * Tell CSME that we are going down so that it won't access the
+	 * memory anymore, make sure this message goes through immediately.
+	 */
+	mei->csa_throttled = false;
+	iwl_mei_send_sap_msg(mei->cldev,
+			     SAP_MSG_NOTIF_HOST_GOES_DOWN);
+
+	for (i = 0; i < 10; i++) {
+		if (!iwl_mei_host_to_me_data_pending(mei))
+			break;
+
+		msleep(5);
+	}
+
+	/*
+	 * If we couldn't make sure that CSME saw the HOST_GOES_DOWN message,
+	 * it means that it will probably keep reading memory that we are going
+	 * to unmap and free, expect IOMMU error messages.
+	 */
+	if (i == 10)
+		IWL_MEI_ERR(mei->cldev,
+			    "Couldn't get ACK from CSME on HOST_GOES_DOWN message\n");
+
+	mutex_unlock(&iwl_mei_mutex);
+
+	/*
+	 * This looks strange, but this lock is taken here to make sure that
+	 * iwl_mei_add_data_to_ring called from the Tx path sees that we
+	 * clear the IWL_MEI_STATUS_SAP_CONNECTED bit.
+	 * Rx isn't a problem because the rx_handler can't be called after
+	 * having been unregistered.
+	 */
+	spin_lock_bh(&mei->data_q_lock);
+	clear_bit(IWL_MEI_STATUS_SAP_CONNECTED, &iwl_mei_status);
+	spin_unlock_bh(&mei->data_q_lock);
+
+	if (iwl_mei_cache.ops)
+		iwl_mei_cache.ops->rfkill(iwl_mei_cache.priv, false);
+
+	/*
+	 * mei_cldev_disable will return only after all the MEI Rx is done.
+	 * It must be called when iwl_mei_mutex is *not* held, since it waits
+	 * for our Rx handler to complete.
+	 * After it returns, no new Rx will start.
+	 */
+	WARN_ON(mei_cldev_disable(cldev));
+
+	/*
+	 * Since the netdev was already removed and the netdev's removal
+	 * includes a call to synchronize_net() so that we know there won't be
+	 * any new Rx that will trigger the following workers.
+	 */
+	cancel_work_sync(&mei->send_csa_msg_wk);
+	cancel_delayed_work_sync(&mei->csa_throttle_end_wk);
+
+	/*
+	 * If someone waits for the ownership, let him know that we are going
+	 * down and that we are not connected anymore. He'll be able to take
+	 * the device.
+	 */
+	wake_up_all(&mei->get_ownership_wq);
+
+	mutex_lock(&iwl_mei_mutex);
+
+	iwl_mei_global_cldev = NULL;
+
+	wake_up_all(&mei->get_nvm_wq);
+
+	iwl_mei_free_shared_mem(cldev);
+
+	iwl_mei_dbgfs_unregister(mei);
+
+	mei_cldev_set_drvdata(cldev, NULL);
+
+	kfree(mei->nvm);
+
+	kfree(mei->filters);
+
+	devm_kfree(&cldev->dev, mei);
+
+	mutex_unlock(&iwl_mei_mutex);
+}
+
+static struct mei_cl_device_id iwl_mei_tbl[] = {
+	{ KBUILD_MODNAME, MEI_WLAN_UUID, MEI_CL_VERSION_ANY},
+
+	/* required last entry */
+	{ }
+};
+
+/*
+ * Do not export the device table because this module is loaded by
+ * iwlwifi's dependency.
+ */
+
+static struct mei_cl_driver iwl_mei_cl_driver = {
+	.id_table = iwl_mei_tbl,
+	.name = KBUILD_MODNAME,
+	.probe = iwl_mei_probe,
+	.remove = iwl_mei_remove,
+};
+
+module_mei_cl_driver(iwl_mei_cl_driver);
diff --git a/drivers/net/wireless/intel/iwlwifi/mei/net.c b/drivers/net/wireless/intel/iwlwifi/mei/net.c
new file mode 100644
index 000000000000..55e59764da81
--- /dev/null
+++ b/drivers/net/wireless/intel/iwlwifi/mei/net.c
@@ -0,0 +1,409 @@
+// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+/*
+ * Copyright (C) 2021 Intel Corporation
+ */
+
+#include <uapi/linux/if_ether.h>
+#include <uapi/linux/if_arp.h>
+#include <uapi/linux/icmp.h>
+
+#include <linux/etherdevice.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <linux/ieee80211.h>
+
+#include <net/cfg80211.h>
+#include <net/ip.h>
+
+#include <linux/if_arp.h>
+#include <linux/icmp.h>
+#include <linux/udp.h>
+#include <linux/ip.h>
+#include <linux/mm.h>
+
+#include "internal.h"
+#include "sap.h"
+#include "iwl-mei.h"
+
+/*
+ * Returns true if further filtering should be stopped. Only in that case
+ * pass_to_csme and rx_handler_res are set. Otherwise, next level of filters
+ * should be checked.
+ */
+static bool iwl_mei_rx_filter_eth(const struct ethhdr *ethhdr,
+				  const struct iwl_sap_oob_filters *filters,
+				  bool *pass_to_csme,
+				  rx_handler_result_t *rx_handler_res)
+{
+	const struct iwl_sap_eth_filter *filt;
+
+	/* This filter is not relevant for UCAST packet */
+	if (!is_multicast_ether_addr(ethhdr->h_dest) ||
+	    is_broadcast_ether_addr(ethhdr->h_dest))
+		return false;
+
+	for (filt = &filters->eth_filters[0];
+	     filt < &filters->eth_filters[0] + ARRAY_SIZE(filters->eth_filters);
+	     filt++) {
+		/* Assume there are no enabled filter after a disabled one */
+		if (!(filt->flags & SAP_ETH_FILTER_ENABLED))
+			break;
+
+		if (compare_ether_header(filt->mac_address, ethhdr->h_dest))
+			continue;
+
+		/* Packet needs to reach the host's stack */
+		if (filt->flags & SAP_ETH_FILTER_COPY)
+			*rx_handler_res = RX_HANDLER_PASS;
+		else
+			*rx_handler_res = RX_HANDLER_CONSUMED;
+
+		/* We have an authoritative answer, stop filtering */
+		if (filt->flags & SAP_ETH_FILTER_STOP) {
+			*pass_to_csme = true;
+			return true;
+		}
+
+		return false;
+	}
+
+	 /* MCAST frames that don't match layer 2 filters are not sent to ME */
+	*pass_to_csme  = false;
+
+	return true;
+}
+
+/*
+ * Returns true iff the frame should be passed to CSME in which case
+ * rx_handler_res is set.
+ */
+static bool iwl_mei_rx_filter_arp(struct sk_buff *skb,
+				  const struct iwl_sap_oob_filters *filters,
+				  rx_handler_result_t *rx_handler_res)
+{
+	const struct iwl_sap_ipv4_filter *filt = &filters->ipv4_filter;
+	const struct arphdr *arp;
+	const __be32 *target_ip;
+	u32 flags = le32_to_cpu(filt->flags);
+
+	if (!pskb_may_pull(skb, arp_hdr_len(skb->dev)))
+		return false;
+
+	arp = arp_hdr(skb);
+
+	/* Handle only IPv4 over ethernet ARP frames */
+	if (arp->ar_hrd != htons(ARPHRD_ETHER) ||
+	    arp->ar_pro != htons(ETH_P_IP))
+		return false;
+
+	/*
+	 * After the ARP header, we have:
+	 * src MAC address   - 6 bytes
+	 * src IP address    - 4 bytes
+	 * target MAC addess - 6 bytes
+	 */
+	target_ip = (void *)((u8 *)(arp + 1) +
+			     ETH_ALEN + sizeof(__be32) + ETH_ALEN);
+
+	/*
+	 * ARP request is forwarded to ME only if IP address match in the
+	 * ARP request's target ip field.
+	 */
+	if (arp->ar_op == htons(ARPOP_REQUEST) &&
+	    (filt->flags & cpu_to_le32(SAP_IPV4_FILTER_ARP_REQ_PASS)) &&
+	    (filt->ipv4_addr == 0 || filt->ipv4_addr == *target_ip)) {
+		if (flags & SAP_IPV4_FILTER_ARP_REQ_COPY)
+			*rx_handler_res = RX_HANDLER_PASS;
+		else
+			*rx_handler_res = RX_HANDLER_CONSUMED;
+
+		return true;
+	}
+
+	/* ARP reply is always forwarded to ME regardless of the IP */
+	if (flags & SAP_IPV4_FILTER_ARP_RESP_PASS &&
+	    arp->ar_op == htons(ARPOP_REPLY)) {
+		if (flags & SAP_IPV4_FILTER_ARP_RESP_COPY)
+			*rx_handler_res = RX_HANDLER_PASS;
+		else
+			*rx_handler_res = RX_HANDLER_CONSUMED;
+
+		return true;
+	}
+
+	return false;
+}
+
+static bool
+iwl_mei_rx_filter_tcp_udp(struct sk_buff *skb, bool  ip_match,
+			  const struct iwl_sap_oob_filters *filters,
+			  rx_handler_result_t *rx_handler_res)
+{
+	const struct iwl_sap_flex_filter *filt;
+
+	for (filt = &filters->flex_filters[0];
+	     filt < &filters->flex_filters[0] + ARRAY_SIZE(filters->flex_filters);
+	     filt++) {
+		if (!(filt->flags & SAP_FLEX_FILTER_ENABLED))
+			break;
+
+		/*
+		 * We are required to have a match on the IP level and we didn't
+		 * have such match.
+		 */
+		if ((filt->flags &
+		     (SAP_FLEX_FILTER_IPV4 | SAP_FLEX_FILTER_IPV6)) &&
+		    !ip_match)
+			continue;
+
+		if ((filt->flags & SAP_FLEX_FILTER_UDP) &&
+		    ip_hdr(skb)->protocol != IPPROTO_UDP)
+			continue;
+
+		if ((filt->flags & SAP_FLEX_FILTER_TCP) &&
+		    ip_hdr(skb)->protocol != IPPROTO_TCP)
+			continue;
+
+		/*
+		 * We must have either a TCP header or a UDP header, both
+		 * starts with a source port and then a destination port.
+		 * Both are big endian words.
+		 * Use a UDP header and that will work for TCP as well.
+		 */
+		if ((filt->src_port && filt->src_port != udp_hdr(skb)->source) ||
+		    (filt->dst_port && filt->dst_port != udp_hdr(skb)->dest))
+			continue;
+
+		if (filt->flags & SAP_FLEX_FILTER_COPY)
+			*rx_handler_res = RX_HANDLER_PASS;
+		else
+			*rx_handler_res = RX_HANDLER_CONSUMED;
+
+		return true;
+	}
+
+	return false;
+}
+
+static bool iwl_mei_rx_filter_ipv4(struct sk_buff *skb,
+				   const struct iwl_sap_oob_filters *filters,
+				   rx_handler_result_t *rx_handler_res)
+{
+	const struct iwl_sap_ipv4_filter *filt = &filters->ipv4_filter;
+	const struct iphdr *iphdr;
+	unsigned int iphdrlen;
+	bool match;
+
+	if (!pskb_may_pull(skb, skb_network_offset(skb) + sizeof(*iphdr)) ||
+	    !pskb_may_pull(skb, skb_network_offset(skb) +
+			   sizeof(ip_hdrlen(skb) - sizeof(*iphdr))))
+		return false;
+
+	iphdrlen = ip_hdrlen(skb);
+	iphdr = ip_hdr(skb);
+	match = !filters->ipv4_filter.ipv4_addr ||
+		filters->ipv4_filter.ipv4_addr == iphdr->daddr;
+
+	skb_set_transport_header(skb, skb_network_offset(skb) + iphdrlen);
+
+	switch (ip_hdr(skb)->protocol) {
+	case IPPROTO_UDP:
+	case IPPROTO_TCP:
+		/*
+		 * UDP header is shorter than TCP header and we look at the first bytes
+		 * of the header anyway (see below).
+		 * If we have a truncated TCP packet, let CSME handle this.
+		 */
+		if (!pskb_may_pull(skb, skb_transport_offset(skb) +
+				   sizeof(struct udphdr)))
+			return false;
+
+		return iwl_mei_rx_filter_tcp_udp(skb, match,
+						 filters, rx_handler_res);
+
+	case IPPROTO_ICMP: {
+		struct icmphdr *icmp;
+
+		if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(*icmp)))
+			return false;
+
+		icmp = icmp_hdr(skb);
+
+		/*
+		 * Don't pass echo requests to ME even if it wants it as we
+		 * want the host to answer.
+		 */
+		if ((filt->flags & cpu_to_le32(SAP_IPV4_FILTER_ICMP_PASS)) &&
+		    match && (icmp->type != ICMP_ECHO || icmp->code != 0)) {
+			if (filt->flags & cpu_to_le32(SAP_IPV4_FILTER_ICMP_COPY))
+				*rx_handler_res = RX_HANDLER_PASS;
+			else
+				*rx_handler_res = RX_HANDLER_CONSUMED;
+
+			return true;
+		}
+		break;
+		}
+	case IPPROTO_ICMPV6:
+		/* TODO: Should we have the same ICMP request logic here too? */
+		if ((filters->icmpv6_flags & cpu_to_le32(SAP_ICMPV6_FILTER_ENABLED) &&
+		     match)) {
+			if (filters->icmpv6_flags &
+			    cpu_to_le32(SAP_ICMPV6_FILTER_COPY))
+				*rx_handler_res = RX_HANDLER_PASS;
+			else
+				*rx_handler_res = RX_HANDLER_CONSUMED;
+
+			return true;
+		}
+		break;
+	default:
+		return false;
+	}
+
+	return false;
+}
+
+static bool iwl_mei_rx_filter_ipv6(struct sk_buff *skb,
+				   const struct iwl_sap_oob_filters *filters,
+				   rx_handler_result_t *rx_handler_res)
+{
+	*rx_handler_res = RX_HANDLER_PASS;
+
+	/* TODO */
+
+	return false;
+}
+
+static rx_handler_result_t
+iwl_mei_rx_pass_to_csme(struct sk_buff *skb,
+			const struct iwl_sap_oob_filters *filters,
+			bool *pass_to_csme)
+{
+	const struct ethhdr *ethhdr = (void *)skb_mac_header(skb);
+	rx_handler_result_t rx_handler_res = RX_HANDLER_PASS;
+	bool (*filt_handler)(struct sk_buff *skb,
+			     const struct iwl_sap_oob_filters *filters,
+			     rx_handler_result_t *rx_handler_res);
+
+	/*
+	 * skb->data points the IP header / ARP header and the ETH header
+	 * is in the headroom.
+	 */
+	skb_reset_network_header(skb);
+
+	/*
+	 * MCAST IP packets sent by us are received again here without
+	 * an ETH header. Drop them here.
+	 */
+	if (!skb_mac_offset(skb))
+		return RX_HANDLER_PASS;
+
+	if (WARN_ON_ONCE(skb_headroom(skb) < sizeof(*ethhdr)))
+		return RX_HANDLER_PASS;
+
+	if (iwl_mei_rx_filter_eth(ethhdr, filters,
+				  pass_to_csme, &rx_handler_res))
+		return rx_handler_res;
+
+	switch (skb->protocol) {
+	case htons(ETH_P_IP):
+		filt_handler = iwl_mei_rx_filter_ipv4;
+		break;
+	case htons(ETH_P_ARP):
+		filt_handler = iwl_mei_rx_filter_arp;
+		break;
+	case htons(ETH_P_IPV6):
+		filt_handler = iwl_mei_rx_filter_ipv6;
+		break;
+	default:
+		*pass_to_csme = false;
+		return rx_handler_res;
+	}
+
+	*pass_to_csme = filt_handler(skb, filters, &rx_handler_res);
+
+	return rx_handler_res;
+}
+
+rx_handler_result_t iwl_mei_rx_filter(struct sk_buff *orig_skb,
+				      const struct iwl_sap_oob_filters *filters,
+				      bool *pass_to_csme)
+{
+	rx_handler_result_t ret;
+	struct sk_buff *skb;
+
+	ret = iwl_mei_rx_pass_to_csme(orig_skb, filters, pass_to_csme);
+
+	if (!*pass_to_csme)
+		return RX_HANDLER_PASS;
+
+	if (ret == RX_HANDLER_PASS)
+		skb = skb_copy(orig_skb, GFP_ATOMIC);
+	else
+		skb = orig_skb;
+
+	/* CSME wants the MAC header as well, push it back */
+	skb_push(skb, skb->data - skb_mac_header(skb));
+
+	/*
+	 * Add the packet that CSME wants to get to the ring. Don't send the
+	 * Check Shared Area HECI message since this is not possible from the
+	 * Rx context. The caller will schedule a worker to do just that.
+	 */
+	iwl_mei_add_data_to_ring(skb, false);
+
+	/*
+	 * In case we drop the packet, don't free it, the caller will do that
+	 * for us
+	 */
+	if (ret == RX_HANDLER_PASS)
+		dev_kfree_skb(skb);
+
+	return ret;
+}
+
+#define DHCP_SERVER_PORT 67
+#define DHCP_CLIENT_PORT 68
+void iwl_mei_tx_copy_to_csme(struct sk_buff *origskb, unsigned int ivlen)
+{
+	struct ieee80211_hdr *hdr;
+	struct sk_buff *skb;
+	struct ethhdr ethhdr;
+	struct ethhdr *eth;
+
+	/* Catch DHCP packets */
+	if (origskb->protocol != htons(ETH_P_IP) ||
+	    ip_hdr(origskb)->protocol != IPPROTO_UDP ||
+	    udp_hdr(origskb)->source != htons(DHCP_CLIENT_PORT) ||
+	    udp_hdr(origskb)->dest != htons(DHCP_SERVER_PORT))
+		return;
+
+	/*
+	 * We could be a bit less aggressive here and not copy everything, but
+	 * this is very rare anyway, do don't bother much.
+	 */
+	skb = skb_copy(origskb, GFP_ATOMIC);
+	if (!skb)
+		return;
+
+	skb->protocol = origskb->protocol;
+
+	hdr = (void *)skb->data;
+
+	memcpy(ethhdr.h_dest, ieee80211_get_DA(hdr), ETH_ALEN);
+	memcpy(ethhdr.h_source, ieee80211_get_SA(hdr), ETH_ALEN);
+
+	/*
+	 * Remove the ieee80211 header + IV + SNAP but leave the ethertype
+	 * We still have enough headroom for the sap header.
+	 */
+	pskb_pull(skb, ieee80211_hdrlen(hdr->frame_control) + ivlen + 6);
+	eth = skb_push(skb, sizeof(ethhdr.h_dest) + sizeof(ethhdr.h_source));
+	memcpy(eth, &ethhdr, sizeof(ethhdr.h_dest) + sizeof(ethhdr.h_source));
+
+	iwl_mei_add_data_to_ring(skb, true);
+
+	dev_kfree_skb(skb);
+}
+EXPORT_SYMBOL(iwl_mei_tx_copy_to_csme);
diff --git a/drivers/net/wireless/intel/iwlwifi/mei/sap.h b/drivers/net/wireless/intel/iwlwifi/mei/sap.h
new file mode 100644
index 000000000000..505e4333b904
--- /dev/null
+++ b/drivers/net/wireless/intel/iwlwifi/mei/sap.h
@@ -0,0 +1,736 @@
+// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+/*
+ * Copyright (C) 2021 Intel Corporation
+ */
+
+#ifndef __sap_h__
+#define __sap_h__
+
+/**
+ * DOC: Introduction
+ *
+ * SAP is the protocol used by the Intel Wireless driver (iwlwifi)
+ * and the wireless driver implemented in the CSME firmware.
+ * It allows to do several things:
+ * 1) Decide who is the owner of the device: CSME or the host
+ * 2) When the host is the owner of the device, CSME can still
+ * send and receive packets through iwlwifi.
+ *
+ * The protocol uses the ME interface (mei driver) to send
+ * messages to the CSME firmware. Those messages have a header
+ * &struct iwl_sap_me_msg_hdr and this header is followed
+ * by a payload.
+ *
+ * Since this messaging system cannot support high amounts of
+ * traffic, iwlwifi and the CSME firmware's WLAN driver have an
+ * addtional communication pipe to exchange information. The body
+ * of the message is copied to a shared area and the message that
+ * goes over the ME interface just signals the other side
+ * that a new message is waiting in the shared area. The ME
+ * interface is used only for signaling and not to transfer
+ * the payload.
+ *
+ * This shared area of memory is DMA'able mapped to be
+ * writable by both the CSME firmware and iwlwifi. It is
+ * mapped to address space of the device that controls the ME
+ * interface's DMA engine. Any data that iwlwifi needs to
+ * send to the CSME firmware needs to be copied to there.
+ */
+
+/**
+ * DOC: Initial Handshake
+ *
+ * Once we get a link to the CMSE's WLAN driver we start the handshake
+ * to establish the shared memory that will allow the communication between
+ * the CSME's WLAN driver and the host.
+ *
+ * 1) Host sends %SAP_ME_MSG_START message with the physical address
+ * of the shared area.
+ * 2) CSME replies with %SAP_ME_MSG_START_OK which includes the versions
+ * protocol versions supported by CSME.
+ */
+
+/**
+ * DOC: Host and driver state messages
+ *
+ * In order to let CSME konw about the host state and the host driver state,
+ * the host sends messages that let CSME know about the host's state.
+ * When the host driver is loaded, the host sends %SAP_MSG_NOTIF_WIFIDR_UP.
+ * When the host driver is unloaded, the host sends %SAP_MSG_NOTIF_WIFIDR_DOWN.
+ * When the iwlmei is unloaded, %SAP_MSG_NOTIF_HOST_GOES_DOWN is sent to let
+ * CSME know not to access the shared memory anymore since it'll be freed.
+ *
+ * CSME will reply to SAP_MSG_NOTIF_WIFIDR_UP by
+ * %SAP_MSG_NOTIF_AMT_STATE to let the host driver whether CSME can use the
+ * WiFi device or not followed by %SAP_MSG_NOTIF_CSME_CONN_STATUS to inform
+ * the host driver on the connection state of CSME.
+ *
+ * When host is associated to an AP, it must send %SAP_MSG_NOTIF_HOST_LINK_UP
+ * and when it disconnect from the AP, it must send
+ * %SAP_MSG_NOTIF_HOST_LINK_DOWN.
+ */
+
+/**
+ * DOC: Ownership
+ *
+ * The device can be controlled either by the CSME firmware or
+ * by the host driver: iwlwifi. There is a negotiaion between
+ * those two entities to determine who controls (or owns) the
+ * device. Since the CSME can control the device even when the
+ * OS is not working or even missing, the CSME can request the
+ * device if it comes to the conclusion that the OS's host driver
+ * is not operational. This is why the host driver needs to
+ * signal CSME that it is up and running. If the driver is
+ * unloaded, it'll signal CSME that it is going down so that
+ * CSME can take ownership.
+ */
+
+/**
+ * DOC: Ownership transfer
+ *
+ * When the host driver needs the device, it'll send the
+ * %SAP_MSG_NOTIF_HOST_ASKS_FOR_NIC_OWNERSHIP that will be replied by
+ * %SAP_MSG_NOTIF_CSME_REPLY_TO_HOST_OWNERSHIP_REQ which will let the
+ * host know whether the ownership is granted or no. If the ownership is
+ * granted, the hosts sends %SAP_MSG_NOTIF_HOST_OWNERSHIP_CONFIRMED.
+ *
+ * When CSME requests ownership, it'll send the
+ * %SAP_MSG_NOTIF_CSME_TAKING_OWNERSHIP and give some time to host to stop
+ * accessing the device. The host needs to send
+ * %SAP_MSG_NOTIF_CSME_OWNERSHIP_CONFIRMED to confirm that it won't access
+ * the device anymore. If the host failed to send this message fast enough,
+ * CSME will take ownership on the device anyway.
+ * When CSME is willing to release the ownership, it'll send
+ * %SAP_MSG_NOTIF_CSME_CAN_RELEASE_OWNERSHIP.
+ */
+
+/**
+ * DOC: Data messages
+ *
+ * Data messages must be sent and receives on a separate queue in the shared
+ * memory. Almost all the data messages use the %SAP_MSG_DATA_PACKET for both
+ * packets sent by CSME to the host to be sent to the AP or for packets
+ * received from the AP and sent by the host to CSME.
+ * CSME sends filters to the host to let the host what inbound packets it must
+ * send to CSME. Those filters are received by the host as a
+ * %SAP_MSG_NOTIF_CSME_FILTERS command.
+ * The only outbound packets that must be sent to CSME are the DHCP packets.
+ * Those packets must use the %SAP_MSG_CB_DATA_PACKET message.
+ */
+
+/**
+ * enum iwl_sap_me_msg_id - the ID of the ME message
+ * @SAP_ME_MSG_START: See &struct iwl_sap_me_msg_start.
+ * @SAP_ME_MSG_START_OK: See &struct iwl_sap_me_msg_start_ok.
+ * @SAP_ME_MSG_CHECK_SHARED_AREA: This message has no payload.
+ */
+enum iwl_sap_me_msg_id {
+	SAP_ME_MSG_START	= 1,
+	SAP_ME_MSG_START_OK,
+	SAP_ME_MSG_CHECK_SHARED_AREA,
+};
+
+/**
+ * struct iwl_sap_me_msg_hdr - the header of the ME message
+ * @type: the type of the message, see &enum iwl_sap_me_msg_id.
+ * @seq_num: a sequence number used for debug only.
+ * @len: the length of the mssage.
+ */
+struct iwl_sap_me_msg_hdr {
+	__le32 type;
+	__le32 seq_num;
+	__le32 len;
+} __packed;
+
+/**
+ * struct iwl_sap_me_msg_start - used for the %SAP_ME_MSG_START message
+ * @hdr: See &struct iwl_sap_me_msg_hdr.
+ * @shared_mem: physical address of SAP shared memory area.
+ * @init_data_seq_num: seq_num of the first data packet HOST -> CSME.
+ * @init_notif_seq_num: seq_num of the first notification HOST -> CSME.
+ * @supported_versions: The host sends to the CSME a zero-terminated array
+ * of versions its supports.
+ *
+ * This message is sent by the host to CSME and will responded by the
+ * %SAP_ME_MSG_START_OK message.
+ */
+struct iwl_sap_me_msg_start {
+	struct iwl_sap_me_msg_hdr hdr;
+	__le64 shared_mem;
+	__le16 init_data_seq_num;
+	__le16 init_notif_seq_num;
+	u8 supported_versions[64];
+} __packed;
+
+/**
+ * struct iwl_sap_me_msg_start_ok - used for the %SAP_ME_MSG_START_OK
+ * @hdr: See &struct iwl_sap_me_msg_hdr
+ * @init_data_seq_num: Not used.
+ * @init_notif_seq_num: Not used
+ * @supported_version: The version that will be used.
+ * @reserved: For alignment.
+ *
+ * This message is sent by CSME to the host in response to the
+ * %SAP_ME_MSG_START message.
+ */
+struct iwl_sap_me_msg_start_ok {
+	struct iwl_sap_me_msg_hdr hdr;
+	__le16 init_data_seq_num;
+	__le16 init_notif_seq_num;
+	u8 supported_version;
+	u8 reserved[3];
+} __packed;
+
+/**
+ * enum iwl_sap_msg - SAP messages
+ * @SAP_MSG_NOTIF_BOTH_WAYS_MIN: Not used.
+ * @SAP_MSG_NOTIF_PING: No payload. Solicitate a response message (check-alive).
+ * @SAP_MSG_NOTIF_PONG: No payload. The response message.
+ * @SAP_MSG_NOTIF_BOTH_WAYS_MAX: Not used.
+ *
+ * @SAP_MSG_NOTIF_FROM_CSME_MIN: Not used.
+ * @SAP_MSG_NOTIF_CSME_FILTERS: TODO
+ * @SAP_MSG_NOTIF_AMT_STATE: Payload is a DW. Any non-zero value means
+ *	that CSME is enabled.
+ * @SAP_MSG_NOTIF_CSME_REPLY_TO_HOST_OWNERSHIP_REQ: Payload is a DW. 0 means
+ *	the host will not get ownership. Any other value means the host is
+ *	the owner.
+ * @SAP_MSG_NOTIF_CSME_TAKING_OWNERSHIP: No payload.
+ * @SAP_MSG_NOTIF_TRIGGER_IP_REFRESH: No payload.
+ * @SAP_MSG_NOTIF_CSME_CAN_RELEASE_OWNERSHIP: No payload.
+ * @SAP_MSG_NOTIF_NIC_OWNER: Payload is a DW. See &enum iwl_sap_nic_owner.
+ * @SAP_MSG_NOTIF_CSME_CONN_STATUS: See &struct iwl_sap_notif_conn_status.
+ * @SAP_MSG_NOTIF_NVM: See &struct iwl_sap_nvm.
+ * @SAP_MSG_NOTIF_FROM_CSME_MAX: Not used.
+ *
+ * @SAP_MSG_NOTIF_FROM_HOST_MIN: Not used.
+ * @SAP_MSG_NOTIF_BAND_SELECTION: TODO
+ * @SAP_MSG_NOTIF_RADIO_STATE: Payload is a DW.
+ *	See &enum iwl_sap_radio_state_bitmap.
+ * @SAP_MSG_NOTIF_NIC_INFO: See &struct iwl_sap_notif_host_nic_info.
+ * @SAP_MSG_NOTIF_HOST_ASKS_FOR_NIC_OWNERSHIP: No payload.
+ * @SAP_MSG_NOTIF_HOST_SUSPENDS: Payload is a DW. Bitmap described in
+ *	&enum iwl_sap_notif_host_suspends_bitmap.
+ * @SAP_MSG_NOTIF_HOST_RESUMES: Payload is a DW. 0 or 1. 1 says that
+ *	the CSME should re-initialize the init control block.
+ * @SAP_MSG_NOTIF_HOST_GOES_DOWN: No payload.
+ * @SAP_MSG_NOTIF_CSME_OWNERSHIP_CONFIRMED: No payload.
+ * @SAP_MSG_NOTIF_COUNTRY_CODE: See &struct iwl_sap_notif_country_code.
+ * @SAP_MSG_NOTIF_HOST_LINK_UP: See &struct iwl_sap_notif_host_link_up.
+ * @SAP_MSG_NOTIF_HOST_LINK_DOWN: See &struct iwl_sap_notif_host_link_down.
+ * @SAP_MSG_NOTIF_WHO_OWNS_NIC: No payload.
+ * @SAP_MSG_NOTIF_WIFIDR_DOWN: No payload.
+ * @SAP_MSG_NOTIF_WIFIDR_UP: No payload.
+ * @SAP_MSG_NOTIF_HOST_OWNERSHIP_CONFIRMED: No payload.
+ * @SAP_MSG_NOTIF_SAR_LIMITS: See &struct iwl_sap_notif_sar_limits.
+ * @SAP_MSG_NOTIF_GET_NVM: No payload. Triggers %SAP_MSG_NOTIF_NVM.
+ * @SAP_MSG_NOTIF_FROM_HOST_MAX: Not used.
+ *
+ * @SAP_MSG_DATA_MIN: Not used.
+ * @SAP_MSG_DATA_PACKET: Packets that passed the filters defined by
+ *	%SAP_MSG_NOTIF_CSME_FILTERS. The payload is &struct iwl_sap_hdr with
+ *	the payload of the packet immediately afterwards.
+ * @SAP_MSG_CB_DATA_PACKET: Indicates to CSME that we transmitted a specific
+ *	packet. Used only for DHCP transmitted packets. See
+ *	&struct iwl_sap_cb_data.
+ * @SAP_MSG_DATA_MAX: Not used.
+ */
+enum iwl_sap_msg {
+	SAP_MSG_NOTIF_BOTH_WAYS_MIN			= 0,
+	SAP_MSG_NOTIF_PING				= 1,
+	SAP_MSG_NOTIF_PONG				= 2,
+	SAP_MSG_NOTIF_BOTH_WAYS_MAX,
+
+	SAP_MSG_NOTIF_FROM_CSME_MIN			= 500,
+	SAP_MSG_NOTIF_CSME_FILTERS			= SAP_MSG_NOTIF_FROM_CSME_MIN,
+	/* 501 is deprecated */
+	SAP_MSG_NOTIF_AMT_STATE				= 502,
+	SAP_MSG_NOTIF_CSME_REPLY_TO_HOST_OWNERSHIP_REQ	= 503,
+	SAP_MSG_NOTIF_CSME_TAKING_OWNERSHIP		= 504,
+	SAP_MSG_NOTIF_TRIGGER_IP_REFRESH		= 505,
+	SAP_MSG_NOTIF_CSME_CAN_RELEASE_OWNERSHIP	= 506,
+	/* 507 is deprecated */
+	/* 508 is deprecated */
+	/* 509 is deprecated */
+	/* 510 is deprecated */
+	SAP_MSG_NOTIF_NIC_OWNER				= 511,
+	SAP_MSG_NOTIF_CSME_CONN_STATUS			= 512,
+	SAP_MSG_NOTIF_NVM				= 513,
+	SAP_MSG_NOTIF_FROM_CSME_MAX,
+
+	SAP_MSG_NOTIF_FROM_HOST_MIN			= 1000,
+	SAP_MSG_NOTIF_BAND_SELECTION			= SAP_MSG_NOTIF_FROM_HOST_MIN,
+	SAP_MSG_NOTIF_RADIO_STATE			= 1001,
+	SAP_MSG_NOTIF_NIC_INFO				= 1002,
+	SAP_MSG_NOTIF_HOST_ASKS_FOR_NIC_OWNERSHIP	= 1003,
+	SAP_MSG_NOTIF_HOST_SUSPENDS			= 1004,
+	SAP_MSG_NOTIF_HOST_RESUMES			= 1005,
+	SAP_MSG_NOTIF_HOST_GOES_DOWN			= 1006,
+	SAP_MSG_NOTIF_CSME_OWNERSHIP_CONFIRMED		= 1007,
+	SAP_MSG_NOTIF_COUNTRY_CODE			= 1008,
+	SAP_MSG_NOTIF_HOST_LINK_UP			= 1009,
+	SAP_MSG_NOTIF_HOST_LINK_DOWN			= 1010,
+	SAP_MSG_NOTIF_WHO_OWNS_NIC			= 1011,
+	SAP_MSG_NOTIF_WIFIDR_DOWN			= 1012,
+	SAP_MSG_NOTIF_WIFIDR_UP				= 1013,
+	/* 1014 is deprecated */
+	SAP_MSG_NOTIF_HOST_OWNERSHIP_CONFIRMED		= 1015,
+	SAP_MSG_NOTIF_SAR_LIMITS			= 1016,
+	SAP_MSG_NOTIF_GET_NVM				= 1017,
+	SAP_MSG_NOTIF_FROM_HOST_MAX,
+
+	SAP_MSG_DATA_MIN				= 2000,
+	SAP_MSG_DATA_PACKET				= SAP_MSG_DATA_MIN,
+	SAP_MSG_CB_DATA_PACKET				= 2001,
+	SAP_MSG_DATA_MAX,
+};
+
+/**
+ * struct iwl_sap_hdr - prefixes any SAP message
+ * @type: See &enum iwl_sap_msg.
+ * @len: The length of the message (header not included).
+ * @seq_num: For debug.
+ * @payload: The payload of the message.
+ */
+struct iwl_sap_hdr {
+	__le16 type;
+	__le16 len;
+	__le32 seq_num;
+	u8 payload[0];
+};
+
+/**
+ * struct iwl_sap_msg_dw - suits any DW long SAP message
+ * @hdr: The SAP header
+ * @val: The value of the DW.
+ */
+struct iwl_sap_msg_dw {
+	struct iwl_sap_hdr hdr;
+	__le32 val;
+};
+
+/**
+ * enum iwl_sap_nic_owner - used by %SAP_MSG_NOTIF_NIC_OWNER
+ * @SAP_NIC_OWNER_UNKNOWN: Not used.
+ * @SAP_NIC_OWNER_HOST: The host owns the NIC.
+ * @SAP_NIC_OWNER_ME: CSME owns the NIC.
+ */
+enum iwl_sap_nic_owner {
+	SAP_NIC_OWNER_UNKNOWN,
+	SAP_NIC_OWNER_HOST,
+	SAP_NIC_OWNER_ME,
+};
+
+enum iwl_sap_wifi_auth_type {
+	SAP_WIFI_AUTH_TYPE_OPEN		= 0,
+	SAP_WIFI_AUTH_TYPE_SHARED	= 1,
+	SAP_WIFI_AUTH_TYPE_WPA		= 3,
+	SAP_WIFI_AUTH_TYPE_WPA_PSK	= 4,
+	SAP_WIFI_AUTH_TYPE_RSNA		= 6,
+	SAP_WIFI_AUTH_TYPE_RSNA_PSK	= 7,
+	SAP_WIFI_AUTH_TYPE_SAE		= 9,
+	SAP_WIFI_AUTH_TYPE_MAX,
+};
+
+/**
+ * enum iwl_sap_wifi_cipher_alg
+ * @SAP_WIFI_CIPHER_ALG_NONE: TBD
+ * @SAP_WIFI_CIPHER_ALG_WEP: TBD
+ * @SAP_WIFI_CIPHER_ALG_TKIP: TBD
+ * @SAP_WIFI_CIPHER_ALG_CCMP: TBD
+ * @SAP_WIFI_CIPHER_ALG_GCMP: TBD
+ */
+enum iwl_sap_wifi_cipher_alg {
+	SAP_WIFI_CIPHER_ALG_NONE	= 0,
+	SAP_WIFI_CIPHER_ALG_WEP		= 1,
+	SAP_WIFI_CIPHER_ALG_TKIP	= 2,
+	SAP_WIFI_CIPHER_ALG_CCMP	= 4,
+	SAP_WIFI_CIPHER_ALG_GCMP	= 8,
+};
+
+/**
+ * struct iwl_sap_notif_connection_info - nested in other structures
+ * @ssid_len: The length of the SSID.
+ * @ssid: The SSID.
+ * @auth_mode: The authentication mode. See &enum iwl_sap_wifi_auth_type.
+ * @ucast_cipher: The cipher used for unicast packets.
+ *	See &enum iwl_sap_wifi_cipher_alg.
+ * @channel: The channel on which we are associated.
+ * @band: The band on which we are associated.
+ * @reserved: For alignment.
+ * @bssid: The BSSID.
+ * @reserved1: For alignment.
+ */
+struct iwl_sap_notif_connection_info {
+	__le32 ssid_len;
+	u8 ssid[32];
+	__le32 auth_mode;
+	__le32 ucast_cipher;
+	u8 channel;
+	u8 band;
+	__le16 reserved;
+	u8 bssid[6];
+	__le16 reserved1;
+} __packed;
+
+/**
+ * enum iwl_sap_scan_request - for the scan_request field
+ * @SCAN_REQUEST_FILTERING: Filtering is requested.
+ * @SCAN_REQUEST_FAST: Fast scan is requested.
+ */
+enum iwl_sap_scan_request {
+	SCAN_REQUEST_FILTERING	= 1 << 0,
+	SCAN_REQUEST_FAST	= 1 << 1,
+};
+
+/**
+ * struct iwl_sap_notif_conn_status - payload of %SAP_MSG_NOTIF_CSME_CONN_STATUS
+ * @hdr: The SAP header
+ * @link_prot_state: Non-zero if link protection is active.
+ * @scan_request: See &enum iwl_sap_scan_request.
+ * @conn_info: Information about the connection.
+ */
+struct iwl_sap_notif_conn_status {
+	struct iwl_sap_hdr hdr;
+	__le32 link_prot_state;
+	__le32 scan_request;
+	struct iwl_sap_notif_connection_info conn_info;
+} __packed;
+
+/**
+ * enum iwl_sap_radio_state_bitmap - used for %SAP_MSG_NOTIF_RADIO_STATE
+ * @SAP_SW_RFKILL_DEASSERTED: If set, SW RfKill is de-asserted
+ * @SAP_HW_RFKILL_DEASSERTED: If set, HW RfKill is de-asserted
+ *
+ * If both bits are set, then the radio is on.
+ */
+enum iwl_sap_radio_state_bitmap {
+	SAP_SW_RFKILL_DEASSERTED	= 1 << 0,
+	SAP_HW_RFKILL_DEASSERTED	= 1 << 1,
+};
+
+/**
+ * enum iwl_sap_notif_host_suspends_bitmap - used for %SAP_MSG_NOTIF_HOST_SUSPENDS
+ * @SAP_OFFER_NIC: TBD
+ * @SAP_FILTER_CONFIGURED: TBD
+ * @SAP_NLO_CONFIGURED: TBD
+ * @SAP_HOST_OWNS_NIC: TBD
+ * @SAP_LINK_PROTECTED: TBD
+ */
+enum iwl_sap_notif_host_suspends_bitmap {
+	SAP_OFFER_NIC		= 1 << 0,
+	SAP_FILTER_CONFIGURED	= 1 << 1,
+	SAP_NLO_CONFIGURED	= 1 << 2,
+	SAP_HOST_OWNS_NIC	= 1 << 3,
+	SAP_LINK_PROTECTED	= 1 << 4,
+};
+
+/**
+ * struct iwl_sap_notif_country_code - payload of %SAP_MSG_NOTIF_COUNTRY_CODE
+ * @hdr: The SAP header
+ * @mcc: The country code.
+ * @source_id: TBD
+ * @reserved: For alignment.
+ * @diff_time: TBD
+ */
+struct iwl_sap_notif_country_code {
+	struct iwl_sap_hdr hdr;
+	__le16 mcc;
+	u8 source_id;
+	u8 reserved;
+	__le32 diff_time;
+} __packed;
+
+/**
+ * struct iwl_sap_notif_host_link_up - payload of %SAP_MSG_NOTIF_HOST_LINK_UP
+ * @hdr: The SAP header
+ * @conn_info: Information about the connection.
+ * @colloc_channel: The collocated channel
+ * @colloc_band: The band of the collocated channel.
+ * @reserved: For alignment.
+ * @colloc_bssid: The collocated BSSID.
+ * @reserved1: For alignment.
+ */
+struct iwl_sap_notif_host_link_up {
+	struct iwl_sap_hdr hdr;
+	struct iwl_sap_notif_connection_info conn_info;
+	u8 colloc_channel;
+	u8 colloc_band;
+	__le16 reserved;
+	u8 colloc_bssid[6];
+	__le16 reserved1;
+} __packed;
+
+/**
+ * enum iwl_sap_notif_link_down_type - used in &struct iwl_sap_notif_host_link_down
+ * @HOST_LINK_DOWN_TYPE_NONE: TBD
+ * @HOST_LINK_DOWN_TYPE_TEMPORARY: TBD
+ * @HOST_LINK_DOWN_TYPE_LONG: TBD
+ */
+enum iwl_sap_notif_link_down_type {
+	HOST_LINK_DOWN_TYPE_NONE,
+	HOST_LINK_DOWN_TYPE_TEMPORARY,
+	HOST_LINK_DOWN_TYPE_LONG,
+};
+
+/**
+ * struct iwl_sap_notif_host_link_down - payload for %SAP_MSG_NOTIF_HOST_LINK_DOWN
+ * @hdr: The SAP header
+ * @type: See &enum iwl_sap_notif_link_down_type.
+ * @reserved: For alignment.
+ * @reason_valid: If 0, ignore the next field.
+ * @reason: The reason of the disconnection.
+ */
+struct iwl_sap_notif_host_link_down {
+	struct iwl_sap_hdr hdr;
+	u8 type;
+	u8 reserved[2];
+	u8 reason_valid;
+	__le32 reason;
+} __packed;
+
+/**
+ * struct iwl_sap_notif_host_nic_info - payload for %SAP_MSG_NOTIF_NIC_INFO
+ * @hdr: The SAP header
+ * @mac_address: The MAC address as configured to the interface.
+ * @nvm_address: The MAC address as configured in the NVM.
+ */
+struct iwl_sap_notif_host_nic_info {
+	struct iwl_sap_hdr hdr;
+	u8 mac_address[6];
+	u8 nvm_address[6];
+} __packed;
+
+/**
+ * struct iwl_sap_notif_dw - payload is a dw
+ * @hdr: The SAP header.
+ * @dw: The payload.
+ */
+struct iwl_sap_notif_dw {
+	struct iwl_sap_hdr hdr;
+	__le32 dw;
+} __packed;
+
+/**
+ * struct iwl_sap_notif_sar_limits - payload for %SAP_MSG_NOTIF_SAR_LIMITS
+ * @hdr: The SAP header
+ * @sar_chain_info_table: Tx power limits.
+ */
+struct iwl_sap_notif_sar_limits {
+	struct iwl_sap_hdr hdr;
+	__le16 sar_chain_info_table[2][5];
+} __packed;
+
+/**
+ * enum iwl_sap_nvm_caps - capabilities for NVM SAP
+ * @SAP_NVM_CAPS_LARI_SUPPORT: Lari is supported
+ * @SAP_NVM_CAPS_11AX_SUPPORT: 11AX is supported
+ */
+enum iwl_sap_nvm_caps {
+	SAP_NVM_CAPS_LARI_SUPPORT	= BIT(0),
+	SAP_NVM_CAPS_11AX_SUPPORT	= BIT(1),
+};
+
+/**
+ * struct iwl_sap_nvm - payload for %SAP_MSG_NOTIF_NVM
+ * @hdr: The SAP header.
+ * @hw_addr: The MAC address
+ * @n_hw_addrs: The number of MAC addresses
+ * @reserved: For alignment.
+ * @radio_cfg: The radio configuration.
+ * @caps: See &enum iwl_sap_nvm_caps.
+ * @nvm_version: The version of the NVM.
+ * @channels: The data for each channel.
+ */
+struct iwl_sap_nvm {
+	struct iwl_sap_hdr hdr;
+	u8 hw_addr[6];
+	u8 n_hw_addrs;
+	u8 reserved;
+	__le32 radio_cfg;
+	__le32 caps;
+	__le32 nvm_version;
+	__le32 channels[110];
+} __packed;
+
+/**
+ * enum iwl_sap_eth_filter_flags - used in &struct iwl_sap_eth_filter
+ * @SAP_ETH_FILTER_STOP: Do not process further filters.
+ * @SAP_ETH_FILTER_COPY: Copy the packet to the CSME.
+ * @SAP_ETH_FILTER_ENABLED: If false, the filter should be ignored.
+ */
+enum iwl_sap_eth_filter_flags {
+	SAP_ETH_FILTER_STOP    = BIT(0),
+	SAP_ETH_FILTER_COPY    = BIT(1),
+	SAP_ETH_FILTER_ENABLED = BIT(2),
+};
+
+/**
+ * struct iwl_sap_eth_filter - a L2 filter
+ * @mac_address: Address to filter.
+ * @flags: See &enum iwl_sap_eth_filter_flags.
+ */
+struct iwl_sap_eth_filter {
+	u8 mac_address[6];
+	u8 flags;
+} __packed;
+
+/**
+ * enum iwl_sap_flex_filter_flags - used in &struct iwl_sap_flex_filter
+ * @SAP_FLEX_FILTER_COPY: Pass UDP / TCP packets to CSME.
+ * @SAP_FLEX_FILTER_ENABLED: If false, the filter should be ignored.
+ * @SAP_FLEX_FILTER_IPV4: Filter requires match on the IP address as well.
+ * @SAP_FLEX_FILTER_IPV6: Filter requires match on the IP address as well.
+ * @SAP_FLEX_FILTER_TCP: Filter should be applied on TCP packets.
+ * @SAP_FLEX_FILTER_UDP: Filter should be applied on UDP packets.
+ */
+enum iwl_sap_flex_filter_flags {
+	SAP_FLEX_FILTER_COPY		= BIT(0),
+	SAP_FLEX_FILTER_ENABLED		= BIT(1),
+	SAP_FLEX_FILTER_IPV6		= BIT(2),
+	SAP_FLEX_FILTER_IPV4		= BIT(3),
+	SAP_FLEX_FILTER_TCP		= BIT(4),
+	SAP_FLEX_FILTER_UDP		= BIT(5),
+};
+
+/**
+ * struct iwl_sap_flex_filter -
+ * @src_port: Source port in network format.
+ * @dst_port: Destination port in network format.
+ * @flags: Flags and protocol, see &enum iwl_sap_flex_filter_flags.
+ * @reserved: For alignment.
+ */
+struct iwl_sap_flex_filter {
+	__be16 src_port;
+	__be16 dst_port;
+	u8 flags;
+	u8 reserved;
+} __packed;
+
+/**
+ * enum iwl_sap_ipv4_filter_flags - used in &struct iwl_sap_ipv4_filter
+ * @SAP_IPV4_FILTER_ICMP_PASS: Pass ICMP packets to CSME.
+ * @SAP_IPV4_FILTER_ICMP_COPY: Pass ICMP packets to host.
+ * @SAP_IPV4_FILTER_ARP_REQ_PASS: Pass ARP requests to CSME.
+ * @SAP_IPV4_FILTER_ARP_REQ_COPY: Pass ARP requests to host.
+ * @SAP_IPV4_FILTER_ARP_RESP_PASS: Pass ARP responses to CSME.
+ * @SAP_IPV4_FILTER_ARP_RESP_COPY: Pass ARP responses to host.
+ */
+enum iwl_sap_ipv4_filter_flags {
+	SAP_IPV4_FILTER_ICMP_PASS	= BIT(0),
+	SAP_IPV4_FILTER_ICMP_COPY	= BIT(1),
+	SAP_IPV4_FILTER_ARP_REQ_PASS	= BIT(2),
+	SAP_IPV4_FILTER_ARP_REQ_COPY	= BIT(3),
+	SAP_IPV4_FILTER_ARP_RESP_PASS	= BIT(4),
+	SAP_IPV4_FILTER_ARP_RESP_COPY	= BIT(5),
+};
+
+/**
+ * struct iwl_sap_ipv4_filter-
+ * @ipv4_addr: The IP address to filer.
+ * @flags: See &enum iwl_sap_ipv4_filter_flags.
+ */
+struct iwl_sap_ipv4_filter {
+	__be32 ipv4_addr;
+	__le32 flags;
+} __packed;
+
+/**
+ * enum iwl_sap_ipv6_filter_flags -
+ * @SAP_IPV6_ADDR_FILTER_COPY: Pass packets to the host.
+ * @SAP_IPV6_ADDR_FILTER_ENABLED: If false, the filter should be ignored.
+ */
+enum iwl_sap_ipv6_filter_flags {
+	SAP_IPV6_ADDR_FILTER_COPY	= BIT(0),
+	SAP_IPV6_ADDR_FILTER_ENABLED	= BIT(1),
+};
+
+/**
+ * struct iwl_sap_ipv6_filter -
+ * @addr_lo24: Lowest 24 bits of the IPv6 address.
+ * @flags: See &enum iwl_sap_ipv6_filter_flags.
+ */
+struct iwl_sap_ipv6_filter {
+	u8 addr_lo24[3];
+	u8 flags;
+} __packed;
+
+/**
+ * enum iwl_sap_icmpv6_filter_flags -
+ * @SAP_ICMPV6_FILTER_ENABLED: If false, the filter should be ignored.
+ * @SAP_ICMPV6_FILTER_COPY: Pass packets to the host.
+ */
+enum iwl_sap_icmpv6_filter_flags {
+	SAP_ICMPV6_FILTER_ENABLED	= BIT(0),
+	SAP_ICMPV6_FILTER_COPY		= BIT(1),
+};
+
+/**
+ * enum iwl_sap_vlan_filter_flags -
+ * @SAP_VLAN_FILTER_VLAN_ID_MSK: TBD
+ * @SAP_VLAN_FILTER_ENABLED: If false, the filter should be ignored.
+ */
+enum iwl_sap_vlan_filter_flags {
+	SAP_VLAN_FILTER_VLAN_ID_MSK	= 0x0FFF,
+	SAP_VLAN_FILTER_ENABLED		= BIT(15),
+};
+
+/**
+ * struct iwl_sap_oob_filters - Out of band filters (for RX only)
+ * @flex_filters: Array of &struct iwl_sap_flex_filter.
+ * @icmpv6_flags: See &enum iwl_sap_icmpv6_filter_flags.
+ * @ipv6_filters: Array of &struct iwl_sap_ipv6_filter.
+ * @eth_filters: Array of &struct iwl_sap_eth_filter.
+ * @reserved: For alignment.
+ * @ipv4_filter: &struct iwl_sap_ipv4_filter.
+ * @vlan: See &enum iwl_sap_vlan_filter_flags.
+ */
+struct iwl_sap_oob_filters {
+	struct iwl_sap_flex_filter flex_filters[14];
+	__le32 icmpv6_flags;
+	struct iwl_sap_ipv6_filter ipv6_filters[4];
+	struct iwl_sap_eth_filter eth_filters[5];
+	u8 reserved;
+	struct iwl_sap_ipv4_filter ipv4_filter;
+	__le16 vlan[4];
+} __packed;
+
+/**
+ * struct iwl_sap_csme_filters - payload of %SAP_MSG_NOTIF_CSME_FILTERS
+ * @hdr: The SAP header.
+ * @mode: Not used.
+ * @mac_address: Not used.
+ * @reserved: For alignment.
+ * @cbfilters: Not used.
+ * @filters: Out of band filters.
+ */
+struct iwl_sap_csme_filters {
+	struct iwl_sap_hdr hdr;
+	__le32 mode;
+	u8 mac_address[6];
+	__le16 reserved;
+	u8 cbfilters[1728];
+	struct iwl_sap_oob_filters filters;
+} __packed;
+
+#define CB_TX_DHCP_FILT_IDX 30
+/**
+ * struct iwl_sap_cb_data - header to be added for transmitted packets.
+ * @hdr: The SAP header.
+ * @reserved: Not used.
+ * @to_me_filt_status: The filter that matches. Bit %CB_TX_DHCP_FILT_IDX should
+ *	be set for DHCP (the only packet that uses this header).
+ * @reserved2: Not used.
+ * @data_len: The length of the payload.
+ * @payload: The payload of the transmitted packet.
+ */
+struct iwl_sap_cb_data {
+	struct iwl_sap_hdr hdr;
+	__le32 reserved[7];
+	__le32 to_me_filt_status;
+	__le32 reserved2;
+	__le32 data_len;
+	u8 payload[];
+};
+
+#endif /* __sap_h__ */
diff --git a/drivers/net/wireless/intel/iwlwifi/mei/trace-data.h b/drivers/net/wireless/intel/iwlwifi/mei/trace-data.h
new file mode 100644
index 000000000000..9ee1c6072cd9
--- /dev/null
+++ b/drivers/net/wireless/intel/iwlwifi/mei/trace-data.h
@@ -0,0 +1,69 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright(c) 2021        Intel Corporation
+ */
+
+#if !defined(__IWLWIFI_DEVICE_TRACE_IWLWIFI_SAP_DATA) || defined(TRACE_HEADER_MULTI_READ)
+
+#ifndef __IWLWIFI_DEVICE_TRACE_IWLWIFI_SAP_DATA
+enum iwl_sap_data_trace_type {
+	IWL_SAP_RX_DATA_TO_AIR,
+	IWL_SAP_TX_DATA_FROM_AIR,
+	IWL_SAP_RX_DATA_DROPPED_FROM_AIR,
+	IWL_SAP_TX_DHCP,
+};
+
+static inline size_t
+iwlmei_sap_data_offset(enum iwl_sap_data_trace_type trace_type)
+{
+	switch (trace_type) {
+	case IWL_SAP_RX_DATA_TO_AIR:
+		return 0;
+	case IWL_SAP_TX_DATA_FROM_AIR:
+	case IWL_SAP_RX_DATA_DROPPED_FROM_AIR:
+		return sizeof(struct iwl_sap_hdr);
+	case IWL_SAP_TX_DHCP:
+		return sizeof(struct iwl_sap_cb_data);
+	default:
+		WARN_ON_ONCE(1);
+	}
+
+	return 0;
+}
+#endif
+
+#define __IWLWIFI_DEVICE_TRACE_IWLWIFI_SAP_DATA
+
+#include <linux/tracepoint.h>
+#include <linux/skbuff.h>
+#include "sap.h"
+
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM iwlmei_sap_data
+
+TRACE_EVENT(iwlmei_sap_data,
+	TP_PROTO(const struct sk_buff *skb,
+		 enum iwl_sap_data_trace_type trace_type),
+	TP_ARGS(skb, trace_type),
+	TP_STRUCT__entry(
+		__dynamic_array(u8, data,
+				skb->len - iwlmei_sap_data_offset(trace_type))
+		__field(u32, trace_type)
+	),
+	TP_fast_assign(
+		size_t offset = iwlmei_sap_data_offset(trace_type);
+		__entry->trace_type = trace_type;
+		skb_copy_bits(skb, offset, __get_dynamic_array(data),
+			      skb->len - offset);
+	),
+	TP_printk("sap_data:trace_type %d len %d",
+		  __entry->trace_type, __get_dynamic_array_len(data))
+);
+
+#endif /* __IWLWIFI_DEVICE_TRACE_IWLWIFI_SAP_DATA */
+
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH .
+#undef TRACE_INCLUDE_FILE
+#define TRACE_INCLUDE_FILE trace-data
+#include <trace/define_trace.h>
diff --git a/drivers/net/wireless/intel/iwlwifi/mei/trace.c b/drivers/net/wireless/intel/iwlwifi/mei/trace.c
new file mode 100644
index 000000000000..47ac32ef9f69
--- /dev/null
+++ b/drivers/net/wireless/intel/iwlwifi/mei/trace.c
@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2021 Intel Corporation
+ */
+
+#include <linux/module.h>
+
+/* sparse doesn't like tracepoint macros */
+#ifndef __CHECKER__
+
+#define CREATE_TRACE_POINTS
+#include "trace.h"
+#include "trace-data.h"
+
+#endif /* __CHECKER__ */
diff --git a/drivers/net/wireless/intel/iwlwifi/mei/trace.h b/drivers/net/wireless/intel/iwlwifi/mei/trace.h
new file mode 100644
index 000000000000..141dc0e64dd0
--- /dev/null
+++ b/drivers/net/wireless/intel/iwlwifi/mei/trace.h
@@ -0,0 +1,62 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright(c) 2021        Intel Corporation
+ */
+
+#if !defined(__IWLWIFI_DEVICE_TRACE_IWLWIFI_SAP_CMD) || defined(TRACE_HEADER_MULTI_READ)
+#define __IWLWIFI_DEVICE_TRACE_IWLWIFI_SAP_CMD
+
+#include <linux/tracepoint.h>
+
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM iwlmei_sap_cmd
+
+#include "mei/sap.h"
+
+TRACE_EVENT(iwlmei_sap_cmd,
+	TP_PROTO(const struct iwl_sap_hdr *sap_cmd, bool tx),
+	TP_ARGS(sap_cmd, tx),
+	TP_STRUCT__entry(
+		__dynamic_array(u8, cmd,
+				le16_to_cpu(sap_cmd->len) + sizeof(*sap_cmd))
+		__field(u8, tx)
+		__field(u16, type)
+		__field(u16, len)
+		__field(u32, seq)
+	),
+	TP_fast_assign(
+		memcpy(__get_dynamic_array(cmd), sap_cmd,
+		       le16_to_cpu(sap_cmd->len) + sizeof(*sap_cmd));
+		__entry->tx = tx;
+		__entry->type = le16_to_cpu(sap_cmd->type);
+		__entry->len = le16_to_cpu(sap_cmd->len);
+		__entry->seq = le32_to_cpu(sap_cmd->seq_num);
+	),
+	TP_printk("sap_cmd %s: type %d len %d seq %d", __entry->tx ? "Tx" : "Rx",
+		  __entry->type, __entry->len, __entry->seq)
+);
+
+TRACE_EVENT(iwlmei_me_msg,
+	TP_PROTO(const struct iwl_sap_me_msg_hdr *hdr, bool tx),
+	TP_ARGS(hdr, tx),
+	TP_STRUCT__entry(
+		__field(u8, type)
+		__field(u8, tx)
+		__field(u32, seq_num)
+	),
+	TP_fast_assign(
+		__entry->type = le32_to_cpu(hdr->type);
+		__entry->seq_num = le32_to_cpu(hdr->seq_num);
+		__entry->tx = tx;
+	),
+	TP_printk("ME message: %s: type %d seq %d", __entry->tx ? "Tx" : "Rx",
+		  __entry->type, __entry->seq_num)
+);
+
+#endif /* __IWLWIFI_DEVICE_TRACE_IWLWIFI_SAP_CMD */
+
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH .
+#undef TRACE_INCLUDE_FILE
+#define TRACE_INCLUDE_FILE trace
+#include <trace/define_trace.h>
-- 
2.25.1