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Date:   Tue, 14 Jul 2020 16:10:42 -0500
From:   Bjorn Helgaas <helgaas@kernel.org>
To:     Shiju Jose <shiju.jose@huawei.com>
Cc:     linux-acpi@vger.kernel.org, linux-pci@vger.kernel.org,
        linux-kernel@vger.kernel.org, rjw@rjwysocki.net, bp@alien8.de,
        james.morse@arm.com, lenb@kernel.org, tony.luck@intel.com,
        dan.carpenter@oracle.com, zhangliguang@linux.alibaba.com,
        andriy.shevchenko@linux.intel.com, wangkefeng.wang@huawei.com,
        jroedel@suse.de, linuxarm@huawei.com, yangyicong@hisilicon.com,
        jonathan.cameron@huawei.com, tanxiaofei@huawei.com,
        Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Subject: Re: [PATCH v12 2/2] PCI: hip: Add handling of HiSilicon HIP PCIe
 controller errors
Message-ID: <20200714211042.GA419148@bjorn-Precision-5520>
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In-Reply-To: <20200713141019.904-3-shiju.jose@huawei.com>
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[+cc Lorenzo]

On Mon, Jul 13, 2020 at 03:10:19PM +0100, Shiju Jose wrote:
> From: Yicong Yang <yangyicong@hisilicon.com>
> 
> The HiSilicon HIP PCIe controller is capable of handling errors
> on root port and perform port reset separately at each root port.

s/perform/performing/ (to match "handling")

> Add error handling driver for HIP PCIe controller to log
> and report recoverable errors. Perform root port reset and restore
> link status after the recovery.
> 
> Following are some of the PCIe controller's recoverable errors
> 1. completion transmission timeout error.
> 2. CRS retry counter over the threshold error.
> 3. ECC 2 bit errors
> 4. AXI bresponse/rresponse errors etc.
> 
> The driver placed in the drivers/pci/controller/ because the
> HIP PCIe controller does not use DWC ip.

s/ip/IP/

> Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
> Signed-off-by: Shiju Jose <shiju.jose@huawei.com>

OK by me unless Lorenzo has any comments.

Acked-by: Bjorn Helgaas <bhelgaas@google.com>

Looks like Rafael is willing to merge it?

> --
> drivers/pci/controller/Kconfig           |   8 +
> drivers/pci/controller/Makefile          |   1 +
> drivers/pci/controller/pcie-hisi-error.c | 336 +++++++++++++++++++++++++++++++
> 3 files changed, 345 insertions(+)
> create mode 100644 drivers/pci/controller/pcie-hisi-error.c
> ---
>  drivers/pci/controller/Kconfig           |   8 +
>  drivers/pci/controller/Makefile          |   1 +
>  drivers/pci/controller/pcie-hisi-error.c | 327 +++++++++++++++++++++++
>  3 files changed, 336 insertions(+)
>  create mode 100644 drivers/pci/controller/pcie-hisi-error.c
> 
> diff --git a/drivers/pci/controller/Kconfig b/drivers/pci/controller/Kconfig
> index adddf21fa381..b7949b37c029 100644
> --- a/drivers/pci/controller/Kconfig
> +++ b/drivers/pci/controller/Kconfig
> @@ -286,6 +286,14 @@ config PCI_LOONGSON
>  	  Say Y here if you want to enable PCI controller support on
>  	  Loongson systems.
>  
> +config PCIE_HISI_ERR
> +	depends on ARM64 || COMPILE_TEST
> +	depends on ACPI
> +	bool "HiSilicon HIP PCIe controller error handling driver"
> +	help
> +	  Say Y here if you want error handling support
> +	  for the PCIe controller's errors on HiSilicon HIP SoCs
> +
>  source "drivers/pci/controller/dwc/Kconfig"
>  source "drivers/pci/controller/mobiveil/Kconfig"
>  source "drivers/pci/controller/cadence/Kconfig"
> diff --git a/drivers/pci/controller/Makefile b/drivers/pci/controller/Makefile
> index efd9733ead26..90afd865bf6b 100644
> --- a/drivers/pci/controller/Makefile
> +++ b/drivers/pci/controller/Makefile
> @@ -30,6 +30,7 @@ obj-$(CONFIG_PCIE_TANGO_SMP8759) += pcie-tango.o
>  obj-$(CONFIG_VMD) += vmd.o
>  obj-$(CONFIG_PCIE_BRCMSTB) += pcie-brcmstb.o
>  obj-$(CONFIG_PCI_LOONGSON) += pci-loongson.o
> +obj-$(CONFIG_PCIE_HISI_ERR) += pcie-hisi-error.o
>  # pcie-hisi.o quirks are needed even without CONFIG_PCIE_DW
>  obj-y				+= dwc/
>  obj-y				+= mobiveil/
> diff --git a/drivers/pci/controller/pcie-hisi-error.c b/drivers/pci/controller/pcie-hisi-error.c
> new file mode 100644
> index 000000000000..9bd050cadb31
> --- /dev/null
> +++ b/drivers/pci/controller/pcie-hisi-error.c
> @@ -0,0 +1,327 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Driver for handling the PCIe controller errors on
> + * HiSilicon HIP SoCs.
> + *
> + * Copyright (c) 2020 HiSilicon Limited.
> + */
> +
> +#include <linux/acpi.h>
> +#include <acpi/ghes.h>
> +#include <linux/bitops.h>
> +#include <linux/delay.h>
> +#include <linux/pci.h>
> +#include <linux/platform_device.h>
> +#include <linux/kfifo.h>
> +#include <linux/spinlock.h>
> +
> +/* HISI PCIe controller error definitions */
> +#define HISI_PCIE_ERR_MISC_REGS	33
> +
> +#define HISI_PCIE_LOCAL_VALID_VERSION		BIT(0)
> +#define HISI_PCIE_LOCAL_VALID_SOC_ID		BIT(1)
> +#define HISI_PCIE_LOCAL_VALID_SOCKET_ID		BIT(2)
> +#define HISI_PCIE_LOCAL_VALID_NIMBUS_ID		BIT(3)
> +#define HISI_PCIE_LOCAL_VALID_SUB_MODULE_ID	BIT(4)
> +#define HISI_PCIE_LOCAL_VALID_CORE_ID		BIT(5)
> +#define HISI_PCIE_LOCAL_VALID_PORT_ID		BIT(6)
> +#define HISI_PCIE_LOCAL_VALID_ERR_TYPE		BIT(7)
> +#define HISI_PCIE_LOCAL_VALID_ERR_SEVERITY	BIT(8)
> +#define HISI_PCIE_LOCAL_VALID_ERR_MISC		9
> +
> +static guid_t hisi_pcie_sec_guid =
> +	GUID_INIT(0xB2889FC9, 0xE7D7, 0x4F9D,
> +		  0xA8, 0x67, 0xAF, 0x42, 0xE9, 0x8B, 0xE7, 0x72);
> +
> +/*
> + * We pass core id and core port id to the ACPI reset method to identify
> + * certain root port to reset, while the firmware reports sockets port
> + * id which occurs an error. Use the macros here to do the conversion

Maybe: 

  Firmware reports the socket port ID where the error occurred.  These
  macros convert that to the core ID and core port ID required by the
  ACPI reset method.

But even that doesn't quite make sense because you apparently get two
values (edata->core_id, edata->port_id) from firmware.

> + */
> +#define HISI_PCIE_CORE_ID(v)             ((v) >> 3)
> +#define HISI_PCIE_PORT_ID(core, v)       (((v) >> 1) + ((core) << 3))
> +#define HISI_PCIE_CORE_PORT_ID(v)        (((v) & 7) << 1)

These would make more sense reordered and with HISI_PCIE_PORT_ID()
rewritten like this:

  #define HISI_PCIE_PORT_ID(core, v)       (((core) << 3) | ((v) >> 1))
  #define HISI_PCIE_CORE_ID(v)             ((v) >> 3)
  #define HISI_PCIE_CORE_PORT_ID(v)        (((v) & 7) << 1)

> +
> +struct hisi_pcie_error_data {
> +	u64	val_bits;
> +	u8	version;
> +	u8	soc_id;
> +	u8	socket_id;
> +	u8	nimbus_id;
> +	u8	sub_module_id;
> +	u8	core_id;
> +	u8	port_id;
> +	u8	err_severity;
> +	u16	err_type;
> +	u8	reserv[2];
> +	u32	err_misc[HISI_PCIE_ERR_MISC_REGS];
> +};
> +
> +struct hisi_pcie_error_private {
> +	struct notifier_block	nb;
> +	struct device *dev;
> +};
> +
> +enum hisi_pcie_submodule_id {
> +	HISI_PCIE_SUB_MODULE_ID_AP,
> +	HISI_PCIE_SUB_MODULE_ID_TL,
> +	HISI_PCIE_SUB_MODULE_ID_MAC,
> +	HISI_PCIE_SUB_MODULE_ID_DL,
> +	HISI_PCIE_SUB_MODULE_ID_SDI,
> +};
> +
> +static const char * const hisi_pcie_sub_module[] = {
> +	[HISI_PCIE_SUB_MODULE_ID_AP]	= "AP Layer",
> +	[HISI_PCIE_SUB_MODULE_ID_TL]	= "TL Layer",
> +	[HISI_PCIE_SUB_MODULE_ID_MAC]	= "MAC Layer",
> +	[HISI_PCIE_SUB_MODULE_ID_DL]	= "DL Layer",
> +	[HISI_PCIE_SUB_MODULE_ID_SDI]	= "SDI Layer",
> +};
> +
> +enum hisi_pcie_err_severity {
> +	HISI_PCIE_ERR_SEV_RECOVERABLE,
> +	HISI_PCIE_ERR_SEV_FATAL,
> +	HISI_PCIE_ERR_SEV_CORRECTED,
> +	HISI_PCIE_ERR_SEV_NONE,
> +};
> +
> +static const char * const hisi_pcie_error_sev[] = {
> +	[HISI_PCIE_ERR_SEV_RECOVERABLE]	= "recoverable",
> +	[HISI_PCIE_ERR_SEV_FATAL]	= "fatal",
> +	[HISI_PCIE_ERR_SEV_CORRECTED]	= "corrected",
> +	[HISI_PCIE_ERR_SEV_NONE]	= "none",
> +};
> +
> +static const char *hisi_pcie_get_string(const char * const *array,
> +					size_t n, u32 id)
> +{
> +	u32 index;
> +
> +	for (index = 0; index < n; index++) {
> +		if (index == id && array[index])
> +			return array[index];
> +	}
> +
> +	return "unknown";
> +}
> +
> +static int hisi_pcie_port_reset(struct platform_device *pdev,
> +				u32 chip_id, u32 port_id)
> +{
> +	struct device *dev = &pdev->dev;
> +	acpi_handle handle = ACPI_HANDLE(dev);
> +	union acpi_object arg[3];
> +	struct acpi_object_list arg_list;
> +	acpi_status s;
> +	unsigned long long data = 0;
> +
> +	arg[0].type = ACPI_TYPE_INTEGER;
> +	arg[0].integer.value = chip_id;
> +	arg[1].type = ACPI_TYPE_INTEGER;
> +	arg[1].integer.value = HISI_PCIE_CORE_ID(port_id);
> +	arg[2].type = ACPI_TYPE_INTEGER;
> +	arg[2].integer.value = HISI_PCIE_CORE_PORT_ID(port_id);
> +
> +	arg_list.count = 3;
> +	arg_list.pointer = arg;
> +
> +	s = acpi_evaluate_integer(handle, "RST", &arg_list, &data);
> +	if (ACPI_FAILURE(s)) {
> +		dev_err(dev, "No RST method\n");
> +		return -EIO;
> +	}
> +
> +	if (data) {
> +		dev_err(dev, "Failed to Reset\n");
> +		return -EIO;
> +	}
> +
> +	return 0;
> +}
> +
> +static int hisi_pcie_port_do_recovery(struct platform_device *dev,
> +				      u32 chip_id, u32 port_id)
> +{
> +	acpi_status s;
> +	struct device *device = &dev->dev;
> +	acpi_handle root_handle = ACPI_HANDLE(device);
> +	struct acpi_pci_root *pci_root;
> +	struct pci_bus *root_bus;
> +	struct pci_dev *pdev;
> +	u32 domain, busnr, devfn;
> +
> +	s = acpi_get_parent(root_handle, &root_handle);
> +	if (ACPI_FAILURE(s))
> +		return -ENODEV;
> +	pci_root = acpi_pci_find_root(root_handle);
> +	if (!pci_root)
> +		return -ENODEV;
> +	root_bus = pci_root->bus;
> +	domain = pci_root->segment;
> +
> +	busnr = root_bus->number;
> +	devfn = PCI_DEVFN(port_id, 0);
> +	pdev = pci_get_domain_bus_and_slot(domain, busnr, devfn);
> +	if (!pdev) {
> +		dev_info(device, "Fail to get root port %04x:%02x:%02x.%d device\n",
> +			 domain, busnr, PCI_SLOT(devfn), PCI_FUNC(devfn));
> +		return -ENODEV;
> +	}
> +
> +	pci_stop_and_remove_bus_device_locked(pdev);
> +	pci_dev_put(pdev);
> +
> +	if (hisi_pcie_port_reset(dev, chip_id, port_id))
> +		return -EIO;
> +
> +	/*
> +	 * The initialization time of subordinate devices after
> +	 * hot reset is no more than 1s, which is required by
> +	 * the PCI spec v5.0 sec 6.6.1. The time will shorten
> +	 * if Readiness Notifications mechanisms are used. But
> +	 * wait 1s here to adapt any conditions.
> +	 */
> +	ssleep(1UL);
> +
> +	/* add root port and downstream devices */
> +	pci_lock_rescan_remove();
> +	pci_rescan_bus(root_bus);
> +	pci_unlock_rescan_remove();
> +
> +	return 0;
> +}
> +
> +static void hisi_pcie_handle_error(struct platform_device *pdev,
> +				   const struct hisi_pcie_error_data *edata)
> +{
> +	struct device *dev = &pdev->dev;
> +	int idx, rc;
> +	const unsigned long valid_bits[] = {BITMAP_FROM_U64(edata->val_bits)};
> +
> +	if (edata->val_bits == 0) {
> +		dev_warn(dev, "%s: no valid error information\n", __func__);
> +		return;
> +	}
> +
> +	dev_info(dev, "\nHISI : HIP : PCIe controller error\n");
> +	if (edata->val_bits & HISI_PCIE_LOCAL_VALID_SOC_ID)
> +		dev_info(dev, "Table version = %d\n", edata->version);
> +	if (edata->val_bits & HISI_PCIE_LOCAL_VALID_SOCKET_ID)
> +		dev_info(dev, "Socket ID = %d\n", edata->socket_id);
> +	if (edata->val_bits & HISI_PCIE_LOCAL_VALID_NIMBUS_ID)
> +		dev_info(dev, "Nimbus ID = %d\n", edata->nimbus_id);
> +	if (edata->val_bits & HISI_PCIE_LOCAL_VALID_SUB_MODULE_ID)
> +		dev_info(dev, "Sub Module = %s\n",
> +			 hisi_pcie_get_string(hisi_pcie_sub_module,
> +					      ARRAY_SIZE(hisi_pcie_sub_module),
> +					      edata->sub_module_id));
> +	if (edata->val_bits & HISI_PCIE_LOCAL_VALID_CORE_ID)
> +		dev_info(dev, "Core ID = core%d\n", edata->core_id);
> +	if (edata->val_bits & HISI_PCIE_LOCAL_VALID_PORT_ID)
> +		dev_info(dev, "Port ID = port%d\n", edata->port_id);
> +	if (edata->val_bits & HISI_PCIE_LOCAL_VALID_ERR_SEVERITY)
> +		dev_info(dev, "Error severity = %s\n",
> +			 hisi_pcie_get_string(hisi_pcie_error_sev,
> +					      ARRAY_SIZE(hisi_pcie_error_sev),
> +					      edata->err_severity));
> +	if (edata->val_bits & HISI_PCIE_LOCAL_VALID_ERR_TYPE)
> +		dev_info(dev, "Error type = 0x%x\n", edata->err_type);
> +
> +	dev_info(dev, "Reg Dump:\n");
> +	idx = HISI_PCIE_LOCAL_VALID_ERR_MISC;
> +	for_each_set_bit_from(idx, valid_bits,
> +			      HISI_PCIE_LOCAL_VALID_ERR_MISC + HISI_PCIE_ERR_MISC_REGS)
> +		dev_info(dev, "ERR_MISC_%d = 0x%x\n", idx - HISI_PCIE_LOCAL_VALID_ERR_MISC,
> +			 edata->err_misc[idx]);
> +
> +	if (edata->err_severity != HISI_PCIE_ERR_SEV_RECOVERABLE)
> +		return;
> +
> +	/* Recovery for the PCIe controller errors, try reset
> +	 * PCI port for the error recovery
> +	 */
> +	rc = hisi_pcie_port_do_recovery(pdev, edata->socket_id,
> +			HISI_PCIE_PORT_ID(edata->core_id, edata->port_id));
> +	if (rc)
> +		dev_info(dev, "fail to do hisi pcie port reset\n");
> +}
> +
> +static int hisi_pcie_notify_error(struct notifier_block *nb,
> +				  unsigned long event, void *data)
> +{
> +	struct acpi_hest_generic_data *gdata = data;
> +	const struct hisi_pcie_error_data *error_data = acpi_hest_get_payload(gdata);
> +	struct hisi_pcie_error_private *priv;
> +	struct device *dev;
> +	struct platform_device *pdev;
> +	guid_t err_sec_guid;
> +	u8 socket;
> +
> +	import_guid(&err_sec_guid, gdata->section_type);
> +	if (!guid_equal(&err_sec_guid, &hisi_pcie_sec_guid))
> +		return NOTIFY_DONE;
> +
> +	priv = container_of(nb, struct hisi_pcie_error_private, nb);
> +	dev = priv->dev;
> +
> +	if (device_property_read_u8(dev, "socket", &socket))
> +		return NOTIFY_DONE;
> +
> +	if (error_data->socket_id != socket)
> +		return NOTIFY_DONE;
> +
> +	pdev = container_of(dev, struct platform_device, dev);
> +	hisi_pcie_handle_error(pdev, error_data);
> +
> +	return NOTIFY_OK;
> +}
> +
> +static int hisi_pcie_error_handler_probe(struct platform_device *pdev)
> +{
> +	struct hisi_pcie_error_private *priv;
> +	int ret;
> +
> +	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
> +	if (!priv)
> +		return -ENOMEM;
> +
> +	priv->nb.notifier_call = hisi_pcie_notify_error;
> +	priv->dev = &pdev->dev;
> +	ret = ghes_register_vendor_record_notifier(&priv->nb);
> +	if (ret) {
> +		dev_err(&pdev->dev,
> +			"Failed to register hisi pcie controller error handler with apei\n");
> +		return ret;
> +	}
> +
> +	platform_set_drvdata(pdev, priv);
> +
> +	return 0;
> +}
> +
> +static int hisi_pcie_error_handler_remove(struct platform_device *pdev)
> +{
> +	struct hisi_pcie_error_private *priv = platform_get_drvdata(pdev);
> +
> +	ghes_unregister_vendor_record_notifier(&priv->nb);
> +
> +	return 0;
> +}
> +
> +static const struct acpi_device_id hisi_pcie_acpi_match[] = {
> +	{ "HISI0361", 0 },
> +	{ }
> +};
> +
> +static struct platform_driver hisi_pcie_error_handler_driver = {
> +	.driver = {
> +		.name	= "hisi-pcie-error-handler",
> +		.acpi_match_table = hisi_pcie_acpi_match,
> +	},
> +	.probe		= hisi_pcie_error_handler_probe,
> +	.remove		= hisi_pcie_error_handler_remove,
> +};
> +module_platform_driver(hisi_pcie_error_handler_driver);
> +
> +MODULE_DESCRIPTION("HiSilicon HIP PCIe controller error handling driver");
> +MODULE_LICENSE("GPL v2");
> -- 
> 2.17.1
> 
>