This series add support the SSIF BMC driver which is to perform in-band
IPMI communication with their host in management (BMC) side.
SSIF BMC driver in this series is tested with Aspeed AST2500.
Discussion for v5: https://lkml.org/lkml/2021/7/13/868
v6:
+ Drop the use of slave_enable() [Wolfram]
+ Make i2c-aspeed to issue RxCmdLast command on all
I2C_SLAVE_WRITE_REQUESTED event to assert NAK when slave busy [Quan]
+ Make i2c slave to return -EBUSY when it's busy [Quan]
+ Drop the aborting feature as return Completion Code 0xFF may stop
host to retry and make ipmi_ssif.so fails to load [Quan]
+ Add timer to recover slave from busy state when no response [Quan]
+ Clean request/response buffer appropriately [Quan]
+ Add some minor change on error and warning messages [Quan]
v5:
+ Correct the patches order to fix the bisect issue found by
kernel build robot
v4:
+ Fix recursive spinlock [Graeme]
+ Send response with Completion code 0xFF when aborting [Quan]
+ Fix warning with dt_binding_check [Rob]
+ Change aspeed-ssif-bmc.yaml to ssif-bmc.yaml [Quan]
+ Added bounding check on SMBus writes and the whole request [Dan]
+ Moved buffer to end of struct ssif_bmc_ctx to avoid context
corruption if somehow buffer is written past the end [Dan]
+ Return -EINVAL if userspace buffer too small, dont
silence truncate [Corey, Joel]
+ Not necessary to check NONBLOCK in lock [Corey]
+ Enforce one user at a time [Joel]
+ Reject write with invalid response length from userspace [Corey]
+ Add state machines for better ssif bmc state handling [Quan]
+ Drop ssif_bmc_aspeed.c and make ssif_bmc.c is generic
SSIF BMC driver [Quan]
+ Change compatible string "aspeed,ast2500-ssif-bmc" to
"ampere,ssif-bmc" [Quan]
+ Toggle Slave enable in i2c-aspeed to turn on/off slave mode [Ryan]
+ Added slave_enable() to struct i2c_algorithm to control
slave mode and to address the recursive spinlock [Graeme, Ryan]
+ Abort current request with invalid SMBus write or
invalid command [Quan]
+ Abort all request if there is pending response [Quan]
+ Changed validate_pec() to validate_request() [Quan]
+ Add unsupported_smbus_cmd() to handle unknown SMBus command [Quan]
+ Print internal state string for ease investigating issue [Quan]
+ Move to READY state on SLAVE_STOP event [Quan]
+ Change initilize_transfer() to process_smbus_cmd() [Quan]
+ Introduce functions for each slave event [Quan]
v3:
+ Switched binding doc to use DT schema format [Rob]
+ Splited into generic ssif_bmc and aspeed-specific [Corey, Joel]
+ Removed redundant license info [Joel]
+ Switched to use traditional if-else [Joel]
+ Removed unused ssif_bmc_ioctl() [Joel]
+ Made handle_request()/complete_response() to return void [Joel]
+ Refactored send_ssif_bmc_response() and
receive_ssif_bmc_request() [Corey]
+ Remove mutex [Corey]
+ Use spin_lock/unlock_irqsave/restore in callback [Corey]
+ Removed the unnecessary memset [Corey]
+ Switch to use dev_err() [Corey]
+ Combine mask/unmask two interrupts together [Corey]
+ Fixed unhandled Tx done with NAK [Quan]
+ Late ack'ed Tx done w/wo Ack irq [Quan]
+ Use aspeed-specific exported aspeed_set_slave_busy() when
slave busy to fix the deadlock [Graeme, Philipp, Quan]
+ Clean buffer for last multipart read [Quan]
+ Handle unknown incoming command [Quan]
v2:
+ Fixed compiling error with COMPILE_TEST for arc
Dan Carpenter (1):
ipmi: ssif_bmc: Return -EFAULT if copy_from_user() fails
Quan Nguyen (3):
ipmi: ssif_bmc: Add SSIF BMC driver
bindings: ipmi: Add binding for SSIF BMC driver
i2c: aspeed: Assert NAK when slave is busy
.../devicetree/bindings/ipmi/ssif-bmc.yaml | 38 +
drivers/char/ipmi/Kconfig | 11 +
drivers/char/ipmi/Makefile | 1 +
drivers/char/ipmi/ssif_bmc.c | 790 ++++++++++++++++++
drivers/char/ipmi/ssif_bmc.h | 102 +++
drivers/i2c/busses/i2c-aspeed.c | 5 +-
6 files changed, 946 insertions(+), 1 deletion(-)
create mode 100644 Documentation/devicetree/bindings/ipmi/ssif-bmc.yaml
create mode 100644 drivers/char/ipmi/ssif_bmc.c
create mode 100644 drivers/char/ipmi/ssif_bmc.h
--
2.35.1
Add device tree binding document for the SSIF BMC driver.
Signed-off-by: Quan Nguyen <[email protected]>
Message-Id: <[email protected]>
Reviewed-by: Rob Herring <[email protected]>
Signed-off-by: Corey Minyard <[email protected]>
---
v6:
+ None
v5:
+ None
v4:
+ Fix warning with dt_binding_check [Rob]
+ Change aspeed-ssif-bmc.yaml to ssif-bmc.yaml [Quan]
v3:
+ Switched to use DT schema format [Rob]
v2:
+ None
.../devicetree/bindings/ipmi/ssif-bmc.yaml | 38 +++++++++++++++++++
1 file changed, 38 insertions(+)
create mode 100644 Documentation/devicetree/bindings/ipmi/ssif-bmc.yaml
diff --git a/Documentation/devicetree/bindings/ipmi/ssif-bmc.yaml b/Documentation/devicetree/bindings/ipmi/ssif-bmc.yaml
new file mode 100644
index 000000000000..917a577c2f29
--- /dev/null
+++ b/Documentation/devicetree/bindings/ipmi/ssif-bmc.yaml
@@ -0,0 +1,38 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/ipmi/ssif-bmc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: SSIF IPMI BMC interface
+
+description: SSIF IPMI BMC device bindings
+
+maintainers:
+ - Quan Nguyen <[email protected]>
+
+properties:
+ compatible:
+ enum:
+ - ampere,ssif-bmc
+
+ reg:
+ maxItems: 1
+
+required:
+ - compatible
+ - reg
+
+additionalProperties: false
+
+examples:
+ - |
+ i2c {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ ssif-bmc@10 {
+ compatible = "ampere,ssif-bmc";
+ reg = <0x10>;
+ };
+ };
--
2.35.1
From: Dan Carpenter <[email protected]>
The copy_from_user() function returns the number of bytes remaining to
be copied but we should return -EFAULT here.
Fixes: 501c25b59508 ("ipmi: ssif_bmc: Add SSIF BMC driver")
Signed-off-by: Dan Carpenter <[email protected]>
Signed-off-by: Corey Minyard <[email protected]>
Signed-off-by: Quan Nguyen <[email protected]>
---
v6:
+ New add in v6, thanks Dan for the patch [Dan]
drivers/char/ipmi/ssif_bmc.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/drivers/char/ipmi/ssif_bmc.c b/drivers/char/ipmi/ssif_bmc.c
index 62db97773654..91ac2cae756e 100644
--- a/drivers/char/ipmi/ssif_bmc.c
+++ b/drivers/char/ipmi/ssif_bmc.c
@@ -87,9 +87,8 @@ static ssize_t ssif_bmc_write(struct file *file, const char __user *buf, size_t
if (count > sizeof(struct ssif_msg))
return -EINVAL;
- ret = copy_from_user(&msg, buf, count);
- if (ret)
- return ret;
+ if (copy_from_user(&msg, buf, count))
+ return -EFAULT;
if (!msg.len || count < ssif_msg_len(&msg))
return -EINVAL;
--
2.35.1
The SMBus system interface (SSIF) IPMI BMC driver can be used to perform
in-band IPMI communication with their host in management (BMC) side.
Signed-off-by: Quan Nguyen <[email protected]>
---
v6:
+ Drop the use of slave_enable() [Wolfram]
+ Make i2c-aspeed to issue RxCmdLast command on all
I2C_SLAVE_WRITE_REQUESTED event to assert NAK when slave busy [Quan]
+ Make i2c slave to return -EBUSY when it's busy [Quan]
+ Drop the aborting feature as return Completion Code 0xFF may stop
host to retry and make ipmi_ssif.so fails to load [Quan]
+ Add timer to recover slave from busy state when no response [Quan]
+ Clean request/response buffer appropriately [Quan]
+ Add some minor change on error and warning messages [Quan]
v5:
+ None
v4:
+ Send response with Completion code 0xFF when aborting [Quan]
+ Added bounding check on SMBus writes and the whole request [Dan]
+ Moved buffer to end of struct ssif_bmc_ctx to avoid context
corruption if somehow buffer is written past the end [Dan]
+ Return -EINVAL if userspace buffer too small, dont
silence truncate [Corey, Joel]
+ Not necessary to check NONBLOCK in lock [Corey]
+ Enforce one user at a time [Joel]
+ Reject write with invalid response length from userspace [Corey]
+ Add state machines for better ssif bmc state handling [Quan]
+ Drop ssif_bmc_aspeed.c and make ssif_bmc.c is generic
SSIF BMC driver [Quan]
+ Change compatible string "aspeed,ast2500-ssif-bmc" to
"ampere,ssif-bmc" [Quan]
+ Abort current request with invalid SMBus write or
invalid command [Quan]
+ Abort all request if there is pending response [Quan]
+ Changed validate_pec() to validate_request() [Quan]
+ Add unsupported_smbus_cmd() to handle unknown SMBus command [Quan]
+ Print internal state string for ease investigating issue [Quan]
+ Move to READY state on SLAVE_STOP event [Quan]
+ Change initilize_transfer() to process_smbus_cmd() [Quan]
+ Introduce functions for each slave event [Quan]
v3:
+ Removed redundant license info [Joel]
+ Switched to use traditional if-else [Joel]
+ Removed unused ssif_bmc_ioctl() [Joel]
+ Made handle_request()/complete_response() to return void [Joel]
+ Refactored send_ssif_bmc_response() and
receive_ssif_bmc_request() [Corey]
+ Removed mutex [Corey]
+ Use spin_lock/unlock_irqsave/restore in callback [Corey]
+ Removed the unnecessary memset [Corey]
+ Switch to use dev_err() [Corey]
v2:
+ Fixed compiling error with COMPILE_TEST for arc
drivers/char/ipmi/Kconfig | 11 +
drivers/char/ipmi/Makefile | 1 +
drivers/char/ipmi/ssif_bmc.c | 791 +++++++++++++++++++++++++++++++++++
drivers/char/ipmi/ssif_bmc.h | 102 +++++
4 files changed, 905 insertions(+)
create mode 100644 drivers/char/ipmi/ssif_bmc.c
create mode 100644 drivers/char/ipmi/ssif_bmc.h
diff --git a/drivers/char/ipmi/Kconfig b/drivers/char/ipmi/Kconfig
index b061e6b513ed..18a89093d64e 100644
--- a/drivers/char/ipmi/Kconfig
+++ b/drivers/char/ipmi/Kconfig
@@ -169,6 +169,17 @@ config ASPEED_BT_IPMI_BMC
found on Aspeed SOCs (AST2400 and AST2500). The driver
implements the BMC side of the BT interface.
+config SSIF_IPMI_BMC
+ tristate "SSIF IPMI BMC driver"
+ select I2C
+ select I2C_SLAVE
+ help
+ This enables the IPMI SMBus system interface (SSIF) at the
+ management (BMC) side.
+
+ The driver implements the BMC side of the SMBus system
+ interface (SSIF).
+
config IPMB_DEVICE_INTERFACE
tristate 'IPMB Interface handler'
depends on I2C
diff --git a/drivers/char/ipmi/Makefile b/drivers/char/ipmi/Makefile
index 7ce790efad92..cb6138b8ded9 100644
--- a/drivers/char/ipmi/Makefile
+++ b/drivers/char/ipmi/Makefile
@@ -30,3 +30,4 @@ obj-$(CONFIG_ASPEED_BT_IPMI_BMC) += bt-bmc.o
obj-$(CONFIG_ASPEED_KCS_IPMI_BMC) += kcs_bmc_aspeed.o
obj-$(CONFIG_NPCM7XX_KCS_IPMI_BMC) += kcs_bmc_npcm7xx.o
obj-$(CONFIG_IPMB_DEVICE_INTERFACE) += ipmb_dev_int.o
+obj-$(CONFIG_SSIF_IPMI_BMC) += ssif_bmc.o
diff --git a/drivers/char/ipmi/ssif_bmc.c b/drivers/char/ipmi/ssif_bmc.c
new file mode 100644
index 000000000000..62db97773654
--- /dev/null
+++ b/drivers/char/ipmi/ssif_bmc.c
@@ -0,0 +1,791 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * The driver for BMC side of SSIF interface
+ *
+ * Copyright (c) 2022, Ampere Computing LLC
+ *
+ */
+
+#include <linux/i2c.h>
+#include <linux/miscdevice.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/poll.h>
+#include <linux/sched.h>
+#include <linux/mutex.h>
+#include <linux/spinlock.h>
+#include <linux/timer.h>
+#include <linux/jiffies.h>
+
+#include "ssif_bmc.h"
+
+static const char *state_to_string(enum ssif_state state)
+{
+ switch (state) {
+ case SSIF_READY:
+ return "SSIF_READY";
+ case SSIF_START:
+ return "SSIF_START";
+ case SSIF_SMBUS_CMD:
+ return "SSIF_SMBUS_CMD";
+ case SSIF_REQ_RECVING:
+ return "SSIF_REQ_RECVING";
+ case SSIF_RES_SENDING:
+ return "SSIF_RES_SENDING";
+ case SSIF_BAD_SMBUS:
+ return "SSIF_BAD_SMBUS";
+ default:
+ return "SSIF_STATE_UNKNOWN";
+ }
+}
+
+/* Handle SSIF message that will be sent to user */
+static ssize_t ssif_bmc_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
+{
+ struct ssif_bmc_ctx *ssif_bmc = to_ssif_bmc(file);
+ struct ssif_msg msg;
+ unsigned long flags;
+ ssize_t ret;
+
+ spin_lock_irqsave(&ssif_bmc->lock, flags);
+ while (!ssif_bmc->request_available) {
+ spin_unlock_irqrestore(&ssif_bmc->lock, flags);
+ if (file->f_flags & O_NONBLOCK)
+ return -EAGAIN;
+ ret = wait_event_interruptible(ssif_bmc->wait_queue,
+ ssif_bmc->request_available);
+ if (ret)
+ return ret;
+ spin_lock_irqsave(&ssif_bmc->lock, flags);
+ }
+
+ if (count < min_t(ssize_t, ssif_msg_len(&ssif_bmc->request), sizeof(struct ssif_msg))) {
+ spin_unlock_irqrestore(&ssif_bmc->lock, flags);
+ ret = -EINVAL;
+ } else {
+ count = min_t(ssize_t, ssif_msg_len(&ssif_bmc->request), sizeof(struct ssif_msg));
+ memcpy(&msg, &ssif_bmc->request, count);
+ ssif_bmc->request_available = false;
+ spin_unlock_irqrestore(&ssif_bmc->lock, flags);
+
+ ret = copy_to_user(buf, &msg, count);
+ }
+
+ return (ret < 0) ? ret : count;
+}
+
+/* Handle SSIF message that is written by user */
+static ssize_t ssif_bmc_write(struct file *file, const char __user *buf, size_t count,
+ loff_t *ppos)
+{
+ struct ssif_bmc_ctx *ssif_bmc = to_ssif_bmc(file);
+ struct ssif_msg msg;
+ unsigned long flags;
+ ssize_t ret;
+
+ if (count > sizeof(struct ssif_msg))
+ return -EINVAL;
+
+ ret = copy_from_user(&msg, buf, count);
+ if (ret)
+ return ret;
+
+ if (!msg.len || count < ssif_msg_len(&msg))
+ return -EINVAL;
+
+ spin_lock_irqsave(&ssif_bmc->lock, flags);
+ while (ssif_bmc->response_in_progress) {
+ spin_unlock_irqrestore(&ssif_bmc->lock, flags);
+ if (file->f_flags & O_NONBLOCK)
+ return -EAGAIN;
+ ret = wait_event_interruptible(ssif_bmc->wait_queue,
+ !ssif_bmc->response_in_progress);
+ if (ret)
+ return ret;
+ spin_lock_irqsave(&ssif_bmc->lock, flags);
+ }
+
+ memcpy(&ssif_bmc->response, &msg, count);
+ ssif_bmc->is_singlepart_read = (ssif_msg_len(&msg) <= MAX_PAYLOAD_PER_TRANSACTION + 1);
+
+ ssif_bmc->response_in_progress = true;
+
+ /* ssif_bmc not busy */
+ ssif_bmc->busy = false;
+
+ if (ssif_bmc->response_timer_inited) {
+ del_timer(&ssif_bmc->response_timer);
+ ssif_bmc->response_timer_inited = false;
+ }
+ /* Clean old request buffer */
+ memset(&ssif_bmc->request, 0, sizeof(struct ssif_msg));
+
+ spin_unlock_irqrestore(&ssif_bmc->lock, flags);
+
+ return count;
+}
+
+static int ssif_bmc_open(struct inode *inode, struct file *file)
+{
+ struct ssif_bmc_ctx *ssif_bmc = to_ssif_bmc(file);
+ int ret = 0;
+
+ spin_lock_irq(&ssif_bmc->lock);
+ if (!ssif_bmc->running)
+ ssif_bmc->running = 1;
+ else
+ ret = -EBUSY;
+ spin_unlock_irq(&ssif_bmc->lock);
+
+ return ret;
+}
+
+static unsigned int ssif_bmc_poll(struct file *file, poll_table *wait)
+{
+ struct ssif_bmc_ctx *ssif_bmc = to_ssif_bmc(file);
+ unsigned int mask = 0;
+
+ poll_wait(file, &ssif_bmc->wait_queue, wait);
+
+ spin_lock_irq(&ssif_bmc->lock);
+ /* The request is available, userspace application can get the request */
+ if (ssif_bmc->request_available)
+ mask |= POLLIN;
+
+ spin_unlock_irq(&ssif_bmc->lock);
+
+ return mask;
+}
+
+static int ssif_bmc_release(struct inode *inode, struct file *file)
+{
+ struct ssif_bmc_ctx *ssif_bmc = to_ssif_bmc(file);
+
+ spin_lock_irq(&ssif_bmc->lock);
+ ssif_bmc->running = 0;
+ spin_unlock_irq(&ssif_bmc->lock);
+
+ return 0;
+}
+
+/*
+ * System calls to device interface for user apps
+ */
+static const struct file_operations ssif_bmc_fops = {
+ .owner = THIS_MODULE,
+ .open = ssif_bmc_open,
+ .read = ssif_bmc_read,
+ .write = ssif_bmc_write,
+ .release = ssif_bmc_release,
+ .poll = ssif_bmc_poll,
+};
+
+/* Called with ssif_bmc->lock held. */
+static void complete_response(struct ssif_bmc_ctx *ssif_bmc)
+{
+ /* Invalidate response in buffer to denote it having been sent. */
+ ssif_bmc->response.len = 0;
+ ssif_bmc->response_in_progress = false;
+ ssif_bmc->nbytes_processed = 0;
+ ssif_bmc->remain_len = 0;
+ ssif_bmc->busy = false;
+ memset(&ssif_bmc->response_buf, 0, MAX_PAYLOAD_PER_TRANSACTION);
+ wake_up_all(&ssif_bmc->wait_queue);
+}
+
+static void response_timeout(struct timer_list *t)
+{
+ struct ssif_bmc_ctx *ssif_bmc = from_timer(ssif_bmc, t, response_timer);
+ unsigned long flags;
+
+ spin_lock_irqsave(&ssif_bmc->lock, flags);
+
+ /* Recover ssif_bmc from busy */
+ ssif_bmc->busy = false;
+ del_timer(&ssif_bmc->response_timer);
+ ssif_bmc->response_timer_inited = false;
+
+ spin_unlock_irqrestore(&ssif_bmc->lock, flags);
+}
+
+/* Called with ssif_bmc->lock held. */
+static void handle_request(struct ssif_bmc_ctx *ssif_bmc)
+{
+ /* set ssif_bmc to busy waiting for response */
+ ssif_bmc->busy = true;
+
+ /* Request message is available to process */
+ ssif_bmc->request_available = true;
+
+ /* Clean old response buffer */
+ memset(&ssif_bmc->response, 0, sizeof(struct ssif_msg));
+
+ /* This is the new READ request.*/
+ wake_up_all(&ssif_bmc->wait_queue);
+
+ /* Armed timer to recover slave from busy state in case of no response */
+ if (!ssif_bmc->response_timer_inited) {
+ timer_setup(&ssif_bmc->response_timer, response_timeout, 0);
+ ssif_bmc->response_timer_inited = true;
+ }
+ mod_timer(&ssif_bmc->response_timer, jiffies + msecs_to_jiffies(RESPONSE_TIMEOUT));
+}
+
+static void set_multipart_response_buffer(struct ssif_bmc_ctx *ssif_bmc, u8 *val)
+{
+ u8 response_len = 0;
+ int idx = 0;
+ u8 data_len;
+
+ data_len = ssif_bmc->response.len;
+ switch (ssif_bmc->smbus_cmd) {
+ case SSIF_IPMI_MULTIPART_READ_START:
+ /*
+ * Read Start length is 32 bytes.
+ * Read Start transfer first 30 bytes of IPMI response
+ * and 2 special code 0x00, 0x01.
+ */
+ *val = MAX_PAYLOAD_PER_TRANSACTION;
+ ssif_bmc->remain_len = data_len - MAX_IPMI_DATA_PER_START_TRANSACTION;
+ ssif_bmc->block_num = 0;
+
+ ssif_bmc->response_buf[idx++] = 0x00; /* Start Flag */
+ ssif_bmc->response_buf[idx++] = 0x01; /* Start Flag */
+ ssif_bmc->response_buf[idx++] = ssif_bmc->response.netfn_lun;
+ ssif_bmc->response_buf[idx++] = ssif_bmc->response.cmd;
+ ssif_bmc->response_buf[idx++] = ssif_bmc->response.payload[0];
+
+ response_len = MAX_PAYLOAD_PER_TRANSACTION - idx;
+
+ memcpy(&ssif_bmc->response_buf[idx], &ssif_bmc->response.payload[1],
+ response_len);
+ break;
+
+ case SSIF_IPMI_MULTIPART_READ_MIDDLE:
+ /*
+ * IPMI READ Middle or READ End messages can carry up to 31 bytes
+ * IPMI data plus block number byte.
+ */
+ if (ssif_bmc->remain_len < MAX_IPMI_DATA_PER_MIDDLE_TRANSACTION) {
+ /*
+ * This is READ End message
+ * Return length is the remaining response data length
+ * plus block number
+ * Block number 0xFF is to indicate this is last message
+ *
+ */
+ *val = ssif_bmc->remain_len + 1;
+ ssif_bmc->block_num = 0xFF;
+ ssif_bmc->response_buf[idx++] = ssif_bmc->block_num;
+ response_len = ssif_bmc->remain_len;
+ /* Clean the buffer */
+ memset(&ssif_bmc->response_buf[idx], 0, MAX_PAYLOAD_PER_TRANSACTION - idx);
+ } else {
+ /*
+ * This is READ Middle message
+ * Response length is the maximum SMBUS transfer length
+ * Block number byte is incremented
+ * Return length is maximum SMBUS transfer length
+ */
+ *val = MAX_PAYLOAD_PER_TRANSACTION;
+ ssif_bmc->remain_len -= MAX_IPMI_DATA_PER_MIDDLE_TRANSACTION;
+ response_len = MAX_IPMI_DATA_PER_MIDDLE_TRANSACTION;
+ ssif_bmc->response_buf[idx++] = ssif_bmc->block_num;
+ ssif_bmc->block_num++;
+ }
+
+ memcpy(&ssif_bmc->response_buf[idx],
+ ssif_bmc->response.payload + 1 + ssif_bmc->nbytes_processed,
+ response_len);
+ break;
+
+ default:
+ /* Do not expect to go to this case */
+ dev_err(&ssif_bmc->client->dev,
+ "%s: Unexpected SMBus command 0x%x\n",
+ __func__, ssif_bmc->smbus_cmd);
+ break;
+ }
+
+ ssif_bmc->nbytes_processed += response_len;
+}
+
+/* Process the IPMI response that will be read by master */
+static void handle_read_processed(struct ssif_bmc_ctx *ssif_bmc, u8 *val)
+{
+ u8 *buf;
+ u8 pec_len, addr, len;
+ u8 pec = 0;
+
+ pec_len = ssif_bmc->pec_support ? 1 : 0;
+ /* PEC - Start Read Address */
+ addr = GET_8BIT_ADDR(ssif_bmc->client->addr);
+ pec = i2c_smbus_pec(pec, &addr, 1);
+ /* PEC - SSIF Command */
+ pec = i2c_smbus_pec(pec, &ssif_bmc->smbus_cmd, 1);
+ /* PEC - Restart Write Address */
+ addr = addr | 0x01;
+ pec = i2c_smbus_pec(pec, &addr, 1);
+
+ if (ssif_bmc->is_singlepart_read) {
+ /* Single-part Read processing */
+ buf = (u8 *)&ssif_bmc->response;
+
+ if (ssif_bmc->response.len && ssif_bmc->msg_idx < ssif_bmc->response.len) {
+ ssif_bmc->msg_idx++;
+ *val = buf[ssif_bmc->msg_idx];
+ } else if (ssif_bmc->response.len && ssif_bmc->msg_idx == ssif_bmc->response.len) {
+ ssif_bmc->msg_idx++;
+ *val = i2c_smbus_pec(pec, buf, ssif_msg_len(&ssif_bmc->response));
+ } else {
+ *val = 0;
+ }
+ /* Invalidate response buffer to denote it is sent */
+ if (ssif_bmc->msg_idx + 1 >= (ssif_msg_len(&ssif_bmc->response) + pec_len))
+ complete_response(ssif_bmc);
+ } else {
+ /* Multi-part Read processing */
+ switch (ssif_bmc->smbus_cmd) {
+ case SSIF_IPMI_MULTIPART_READ_START:
+ case SSIF_IPMI_MULTIPART_READ_MIDDLE:
+ buf = (u8 *)&ssif_bmc->response_buf;
+ *val = buf[ssif_bmc->msg_idx];
+ ssif_bmc->msg_idx++;
+ break;
+ default:
+ /* Do not expect to go to this case */
+ dev_err(&ssif_bmc->client->dev,
+ "%s: Unexpected SMBus command 0x%x\n",
+ __func__, ssif_bmc->smbus_cmd);
+ break;
+ }
+
+ len = (ssif_bmc->block_num == 0xFF) ?
+ ssif_bmc->remain_len + 1 : MAX_PAYLOAD_PER_TRANSACTION;
+ if (ssif_bmc->msg_idx == (len + 1)) {
+ pec = i2c_smbus_pec(pec, &len, 1);
+ *val = i2c_smbus_pec(pec, ssif_bmc->response_buf, len);
+ }
+ /* Invalidate response buffer to denote last response is sent */
+ if (ssif_bmc->block_num == 0xFF &&
+ ssif_bmc->msg_idx > (ssif_bmc->remain_len + pec_len)) {
+ complete_response(ssif_bmc);
+ }
+ }
+}
+
+static void handle_write_received(struct ssif_bmc_ctx *ssif_bmc, u8 *val)
+{
+ u8 *buf = (u8 *)&ssif_bmc->request;
+
+ if (ssif_bmc->msg_idx >= sizeof(struct ssif_msg))
+ return;
+
+ switch (ssif_bmc->smbus_cmd) {
+ case SSIF_IPMI_SINGLEPART_WRITE:
+ buf[ssif_bmc->msg_idx - 1] = *val;
+ ssif_bmc->msg_idx++;
+
+ break;
+ case SSIF_IPMI_MULTIPART_WRITE_START:
+ if (ssif_bmc->msg_idx == 1)
+ ssif_bmc->request.len = 0;
+
+ fallthrough;
+ case SSIF_IPMI_MULTIPART_WRITE_MIDDLE:
+ /* The len should always be 32 */
+ if (ssif_bmc->msg_idx == 1 && *val != MAX_PAYLOAD_PER_TRANSACTION)
+ dev_warn(&ssif_bmc->client->dev,
+ "Warn: Invalid Multipart Write len");
+
+ fallthrough;
+ case SSIF_IPMI_MULTIPART_WRITE_END:
+ /* Multi-part write, 2nd byte received is length */
+ if (ssif_bmc->msg_idx == 1) {
+ if (*val > MAX_PAYLOAD_PER_TRANSACTION)
+ dev_warn(&ssif_bmc->client->dev,
+ "Warn: Invalid Multipart Write End len");
+
+ ssif_bmc->request.len += *val;
+ ssif_bmc->recv_len = *val;
+
+ /* request len should never exceeded 255 bytes */
+ if (ssif_bmc->request.len > 255)
+ dev_warn(&ssif_bmc->client->dev,
+ "Warn: Invalid request len");
+
+ } else {
+ buf[ssif_bmc->msg_idx - 1 +
+ ssif_bmc->request.len - ssif_bmc->recv_len] = *val;
+ }
+
+ ssif_bmc->msg_idx++;
+
+ break;
+ default:
+ /* Do not expect to go to this case */
+ dev_err(&ssif_bmc->client->dev,
+ "%s: Unexpected SMBus command 0x%x\n",
+ __func__, ssif_bmc->smbus_cmd);
+ break;
+ }
+}
+
+static bool validate_request(struct ssif_bmc_ctx *ssif_bmc)
+{
+ u8 rpec = 0, cpec = 0;
+ bool ret = true;
+ u8 addr, index;
+ u8 *buf;
+
+ buf = (u8 *)&ssif_bmc->request;
+ switch (ssif_bmc->smbus_cmd) {
+ case SSIF_IPMI_SINGLEPART_WRITE:
+ if ((ssif_bmc->msg_idx - 1) == ssif_msg_len(&ssif_bmc->request)) {
+ /* PEC is not included */
+ ssif_bmc->pec_support = false;
+ ret = true;
+ goto exit;
+ }
+
+ if ((ssif_bmc->msg_idx - 1) != (ssif_msg_len(&ssif_bmc->request) + 1)) {
+ dev_err(&ssif_bmc->client->dev, "Error: Unexpected length received %d\n",
+ ssif_msg_len(&ssif_bmc->request));
+ ret = false;
+ goto exit;
+ }
+
+ /* PEC is included */
+ ssif_bmc->pec_support = true;
+ rpec = buf[ssif_bmc->msg_idx - 2];
+ addr = GET_8BIT_ADDR(ssif_bmc->client->addr);
+ cpec = i2c_smbus_pec(cpec, &addr, 1);
+ cpec = i2c_smbus_pec(cpec, &ssif_bmc->smbus_cmd, 1);
+ cpec = i2c_smbus_pec(cpec, buf, ssif_msg_len(&ssif_bmc->request));
+ if (rpec != cpec) {
+ dev_err(&ssif_bmc->client->dev, "Bad PEC 0x%02x vs. 0x%02x\n", rpec, cpec);
+ ret = false;
+ }
+
+ break;
+ case SSIF_IPMI_MULTIPART_WRITE_START:
+ case SSIF_IPMI_MULTIPART_WRITE_MIDDLE:
+ case SSIF_IPMI_MULTIPART_WRITE_END:
+ index = ssif_bmc->request.len - ssif_bmc->recv_len;
+ if ((ssif_bmc->msg_idx - 1 + index) == ssif_msg_len(&ssif_bmc->request)) {
+ /* PEC is not included */
+ ssif_bmc->pec_support = false;
+ ret = true;
+ goto exit;
+ }
+
+ if ((ssif_bmc->msg_idx - 1 + index) != (ssif_msg_len(&ssif_bmc->request) + 1)) {
+ dev_err(&ssif_bmc->client->dev, "Error: Unexpected length received %d\n",
+ ssif_msg_len(&ssif_bmc->request));
+ ret = false;
+ goto exit;
+ }
+
+ /* PEC is included */
+ ssif_bmc->pec_support = true;
+ rpec = buf[ssif_bmc->msg_idx - 2 + index];
+ addr = GET_8BIT_ADDR(ssif_bmc->client->addr);
+ cpec = i2c_smbus_pec(cpec, &addr, 1);
+ cpec = i2c_smbus_pec(cpec, &ssif_bmc->smbus_cmd, 1);
+ cpec = i2c_smbus_pec(cpec, &ssif_bmc->recv_len, 1);
+ /* As SMBus specification does not allow the length
+ * (byte count) in the Write-Block protocol to be zero.
+ * Therefore, it is illegal to have the last Middle
+ * transaction in the sequence carry 32-byte and have
+ * a length of ‘0’ in the End transaction.
+ * But some users may try to use this way and we should
+ * prevent ssif_bmc driver broken in this case.
+ */
+ if (ssif_bmc->recv_len != 0)
+ cpec = i2c_smbus_pec(cpec, buf + 1 + index, ssif_bmc->recv_len);
+
+ if (rpec != cpec) {
+ dev_err(&ssif_bmc->client->dev, "Bad PEC 0x%02x vs. 0x%02x\n", rpec, cpec);
+ ret = false;
+ }
+
+ break;
+ default:
+ /* Do not expect to go to this case */
+ dev_err(&ssif_bmc->client->dev, "%s: Unexpected SMBus command 0x%x\n",
+ __func__, ssif_bmc->smbus_cmd);
+ ret = false;
+ break;
+ }
+
+exit:
+ return ret;
+}
+
+static bool unsupported_smbus_cmd(u8 cmd)
+{
+ if (cmd == SSIF_IPMI_SINGLEPART_READ ||
+ cmd == SSIF_IPMI_SINGLEPART_WRITE ||
+ cmd == SSIF_IPMI_MULTIPART_WRITE_START ||
+ cmd == SSIF_IPMI_MULTIPART_WRITE_MIDDLE ||
+ cmd == SSIF_IPMI_MULTIPART_WRITE_END ||
+ cmd == SSIF_IPMI_MULTIPART_READ_START ||
+ cmd == SSIF_IPMI_MULTIPART_READ_MIDDLE)
+ return false;
+
+ return true;
+}
+
+static void process_smbus_cmd(struct ssif_bmc_ctx *ssif_bmc, u8 *val)
+{
+ /* SMBUS command can vary (single or multi-part) */
+ ssif_bmc->smbus_cmd = *val;
+ ssif_bmc->msg_idx++;
+
+ if (unsupported_smbus_cmd(*val))
+ dev_warn(&ssif_bmc->client->dev, "Warn: Unknown SMBus command");
+
+ if (*val == SSIF_IPMI_SINGLEPART_WRITE ||
+ *val == SSIF_IPMI_MULTIPART_WRITE_START) {
+ /*
+ * The response maybe not come in-time, causing host SSIF driver
+ * to timeout and resend a new request. In such case check for
+ * pending response and clear it
+ */
+ if (ssif_bmc->response_in_progress)
+ complete_response(ssif_bmc);
+ }
+}
+
+static void on_read_requested_event(struct ssif_bmc_ctx *ssif_bmc, u8 *val)
+{
+ if (ssif_bmc->state == SSIF_READY ||
+ ssif_bmc->state == SSIF_START ||
+ ssif_bmc->state == SSIF_REQ_RECVING ||
+ ssif_bmc->state == SSIF_RES_SENDING) {
+ ssif_bmc->state = SSIF_BAD_SMBUS;
+ dev_warn(&ssif_bmc->client->dev,
+ "Warn: %s unexpected READ REQUESTED in state=%s\n",
+ __func__, state_to_string(ssif_bmc->state));
+
+ } else if (ssif_bmc->state == SSIF_SMBUS_CMD) {
+ ssif_bmc->state = SSIF_RES_SENDING;
+ }
+
+ ssif_bmc->msg_idx = 0;
+ if (ssif_bmc->is_singlepart_read)
+ *val = ssif_bmc->response.len;
+ else
+ set_multipart_response_buffer(ssif_bmc, val);
+}
+
+static void on_read_processed_event(struct ssif_bmc_ctx *ssif_bmc, u8 *val)
+{
+ if (ssif_bmc->state == SSIF_READY ||
+ ssif_bmc->state == SSIF_START ||
+ ssif_bmc->state == SSIF_REQ_RECVING ||
+ ssif_bmc->state == SSIF_SMBUS_CMD) {
+ dev_warn(&ssif_bmc->client->dev,
+ "Warn: %s unexpected READ PROCESSED in state=%s\n",
+ __func__, state_to_string(ssif_bmc->state));
+ ssif_bmc->state = SSIF_BAD_SMBUS;
+ }
+
+ handle_read_processed(ssif_bmc, val);
+}
+
+static void on_write_requested_event(struct ssif_bmc_ctx *ssif_bmc, u8 *val)
+{
+ ssif_bmc->msg_idx = 0;
+
+ if (ssif_bmc->state == SSIF_READY || ssif_bmc->state == SSIF_SMBUS_CMD) {
+ ssif_bmc->state = SSIF_START;
+
+ } else if (ssif_bmc->state == SSIF_START ||
+ ssif_bmc->state == SSIF_REQ_RECVING ||
+ ssif_bmc->state == SSIF_RES_SENDING) {
+ dev_warn(&ssif_bmc->client->dev,
+ "Warn: %s unexpected WRITE REQUEST in state=%s\n",
+ __func__, state_to_string(ssif_bmc->state));
+ ssif_bmc->state = SSIF_BAD_SMBUS;
+ }
+}
+
+static void on_write_received_event(struct ssif_bmc_ctx *ssif_bmc, u8 *val)
+{
+ if (ssif_bmc->state == SSIF_READY || ssif_bmc->state == SSIF_RES_SENDING) {
+ dev_warn(&ssif_bmc->client->dev,
+ "Warn: %s unexpected WRITE RECEIVED in state=%s\n",
+ __func__, state_to_string(ssif_bmc->state));
+ ssif_bmc->state = SSIF_BAD_SMBUS;
+ } else if (ssif_bmc->state == SSIF_START) {
+ ssif_bmc->state = SSIF_SMBUS_CMD;
+ } else if (ssif_bmc->state == SSIF_SMBUS_CMD) {
+ ssif_bmc->state = SSIF_REQ_RECVING;
+ }
+
+ /* This is response sending state */
+ if (ssif_bmc->state == SSIF_REQ_RECVING)
+ handle_write_received(ssif_bmc, val);
+ else if (ssif_bmc->state == SSIF_SMBUS_CMD)
+ process_smbus_cmd(ssif_bmc, val);
+}
+
+static void on_stop_event(struct ssif_bmc_ctx *ssif_bmc, u8 *val)
+{
+ if (ssif_bmc->state == SSIF_READY ||
+ ssif_bmc->state == SSIF_START ||
+ ssif_bmc->state == SSIF_SMBUS_CMD) {
+ dev_warn(&ssif_bmc->client->dev,
+ "Warn: %s unexpected SLAVE STOP in state=%s\n",
+ __func__, state_to_string(ssif_bmc->state));
+
+ } else if (ssif_bmc->state == SSIF_BAD_SMBUS) {
+ dev_warn(&ssif_bmc->client->dev,
+ "Warn: %s received SLAVE STOP from bad state=%s\n",
+ __func__, state_to_string(ssif_bmc->state));
+
+ } else if (ssif_bmc->state == SSIF_REQ_RECVING) {
+ /* A BMC that receives an invalid request drop the data for the write
+ * transaction and any further transactions (read or write) until
+ * the next valid read or write Start transaction is received
+ */
+ if (!validate_request(ssif_bmc))
+ dev_err(&ssif_bmc->client->dev, "Error: invalid pec\n");
+ else if (ssif_bmc->smbus_cmd == SSIF_IPMI_SINGLEPART_WRITE ||
+ ssif_bmc->smbus_cmd == SSIF_IPMI_MULTIPART_WRITE_END)
+ handle_request(ssif_bmc);
+ }
+
+ ssif_bmc->state = SSIF_READY;
+ /* Reset message index */
+ ssif_bmc->msg_idx = 0;
+}
+
+/*
+ * Callback function to handle I2C slave events
+ */
+static int ssif_bmc_cb(struct i2c_client *client, enum i2c_slave_event event, u8 *val)
+{
+ unsigned long flags;
+ struct ssif_bmc_ctx *ssif_bmc = i2c_get_clientdata(client);
+ int ret = 0;
+
+ spin_lock_irqsave(&ssif_bmc->lock, flags);
+
+ switch (event) {
+ case I2C_SLAVE_READ_REQUESTED:
+ on_read_requested_event(ssif_bmc, val);
+ break;
+
+ case I2C_SLAVE_WRITE_REQUESTED:
+ on_write_requested_event(ssif_bmc, val);
+ break;
+
+ case I2C_SLAVE_READ_PROCESSED:
+ on_read_processed_event(ssif_bmc, val);
+ break;
+
+ case I2C_SLAVE_WRITE_RECEIVED:
+ on_write_received_event(ssif_bmc, val);
+ break;
+
+ case I2C_SLAVE_STOP:
+ on_stop_event(ssif_bmc, val);
+ break;
+
+ default:
+ dev_warn(&ssif_bmc->client->dev, "Warn: Unknown i2c slave event\n");
+ break;
+ }
+
+ if (ssif_bmc->busy)
+ ret = -EBUSY;
+
+ spin_unlock_irqrestore(&ssif_bmc->lock, flags);
+
+ return ret;
+}
+
+static int ssif_bmc_probe(struct i2c_client *client, const struct i2c_device_id *id)
+{
+ struct ssif_bmc_ctx *ssif_bmc;
+ int ret;
+
+ ssif_bmc = devm_kzalloc(&client->dev, sizeof(*ssif_bmc), GFP_KERNEL);
+ if (!ssif_bmc)
+ return -ENOMEM;
+
+ spin_lock_init(&ssif_bmc->lock);
+
+ init_waitqueue_head(&ssif_bmc->wait_queue);
+ ssif_bmc->request_available = false;
+ ssif_bmc->response_in_progress = false;
+ ssif_bmc->busy = false;
+ ssif_bmc->response_timer_inited = false;
+
+ /* Register misc device interface */
+ ssif_bmc->miscdev.minor = MISC_DYNAMIC_MINOR;
+ ssif_bmc->miscdev.name = DEVICE_NAME;
+ ssif_bmc->miscdev.fops = &ssif_bmc_fops;
+ ssif_bmc->miscdev.parent = &client->dev;
+ ret = misc_register(&ssif_bmc->miscdev);
+ if (ret)
+ goto out;
+
+ ssif_bmc->client = client;
+ ssif_bmc->client->flags |= I2C_CLIENT_SLAVE;
+
+ /* Register I2C slave */
+ i2c_set_clientdata(client, ssif_bmc);
+ ret = i2c_slave_register(client, ssif_bmc_cb);
+ if (ret) {
+ misc_deregister(&ssif_bmc->miscdev);
+ goto out;
+ }
+
+ return 0;
+out:
+ devm_kfree(&client->dev, ssif_bmc);
+ return ret;
+}
+
+static int ssif_bmc_remove(struct i2c_client *client)
+{
+ struct ssif_bmc_ctx *ssif_bmc = i2c_get_clientdata(client);
+
+ i2c_slave_unregister(client);
+ misc_deregister(&ssif_bmc->miscdev);
+
+ return 0;
+}
+
+static const struct of_device_id ssif_bmc_match[] = {
+ { .compatible = "ampere,ssif-bmc" },
+ { },
+};
+
+static const struct i2c_device_id ssif_bmc_id[] = {
+ { DEVICE_NAME, 0 },
+ { },
+};
+
+MODULE_DEVICE_TABLE(i2c, ssif_bmc_id);
+
+static struct i2c_driver ssif_bmc_driver = {
+ .driver = {
+ .name = DEVICE_NAME,
+ .of_match_table = ssif_bmc_match,
+ },
+ .probe = ssif_bmc_probe,
+ .remove = ssif_bmc_remove,
+ .id_table = ssif_bmc_id,
+};
+
+module_i2c_driver(ssif_bmc_driver);
+
+MODULE_AUTHOR("Quan Nguyen <[email protected]>");
+MODULE_AUTHOR("Chuong Tran <[email protected]>");
+MODULE_DESCRIPTION("Linux device driver of the BMC IPMI SSIF interface.");
+MODULE_LICENSE("GPL");
diff --git a/drivers/char/ipmi/ssif_bmc.h b/drivers/char/ipmi/ssif_bmc.h
new file mode 100644
index 000000000000..9a26f3c252cc
--- /dev/null
+++ b/drivers/char/ipmi/ssif_bmc.h
@@ -0,0 +1,102 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * The driver for BMC side of SSIF interface
+ *
+ * Copyright (c) 2022, Ampere Computing LLC
+ *
+ */
+#ifndef __SSIF_BMC_H__
+#define __SSIF_BMC_H__
+
+#define DEVICE_NAME "ipmi-ssif-host"
+
+#define GET_8BIT_ADDR(addr_7bit) (((addr_7bit) << 1) & 0xff)
+
+/* A standard SMBus Transaction is limited to 32 data bytes */
+#define MAX_PAYLOAD_PER_TRANSACTION 32
+
+#define MAX_IPMI_DATA_PER_START_TRANSACTION 30
+#define MAX_IPMI_DATA_PER_MIDDLE_TRANSACTION 31
+
+#define SSIF_IPMI_SINGLEPART_WRITE 0x2
+#define SSIF_IPMI_SINGLEPART_READ 0x3
+#define SSIF_IPMI_MULTIPART_WRITE_START 0x6
+#define SSIF_IPMI_MULTIPART_WRITE_MIDDLE 0x7
+#define SSIF_IPMI_MULTIPART_WRITE_END 0x8
+#define SSIF_IPMI_MULTIPART_READ_START 0x3
+#define SSIF_IPMI_MULTIPART_READ_MIDDLE 0x9
+
+#define MSG_PAYLOAD_LEN_MAX 252
+/*
+ * IPMI 2.0 Spec, section 12.7 SSIF Timing,
+ * Request-to-Response Time is T6max(250ms) - T1max(20ms) - 3ms = 227ms
+ * Recover ssif_bmc from busy state if it takes upto 500ms
+ */
+#define RESPONSE_TIMEOUT 500 /* ms */
+
+struct ssif_msg {
+ u8 len;
+ u8 netfn_lun;
+ u8 cmd;
+ u8 payload[MSG_PAYLOAD_LEN_MAX];
+} __packed;
+
+static inline u32 ssif_msg_len(struct ssif_msg *ssif_msg)
+{
+ return ssif_msg->len + 1;
+}
+
+/*
+ * SSIF internal states:
+ * SSIF_READY 0x00 : Ready state
+ * SSIF_START 0x01 : Start smbus transaction
+ * SSIF_SMBUS_CMD 0x02 : Received SMBus command
+ * SSIF_REQ_RECVING 0x03 : Receiving request
+ * SSIF_RES_SENDING 0x04 : Sending response
+ * SSIF_BAD_SMBUS 0x05 : Bad SMbus transaction
+ */
+enum ssif_state {
+ SSIF_READY,
+ SSIF_START,
+ SSIF_SMBUS_CMD,
+ SSIF_REQ_RECVING,
+ SSIF_RES_SENDING,
+ SSIF_BAD_SMBUS,
+ SSIF_STATE_MAX
+};
+
+struct ssif_bmc_ctx {
+ struct i2c_client *client;
+ struct miscdevice miscdev;
+ size_t msg_idx;
+ bool pec_support;
+ /* ssif bmc spinlock */
+ spinlock_t lock;
+ wait_queue_head_t wait_queue;
+ u8 running;
+ enum ssif_state state;
+ u8 smbus_cmd;
+ /* Timeout waiting for response */
+ struct timer_list response_timer;
+ bool response_timer_inited;
+ /* Flag to identify a Multi-part Read Transaction */
+ bool is_singlepart_read;
+ u8 nbytes_processed;
+ u8 remain_len;
+ u8 recv_len;
+ /* Block Number of a Multi-part Read Transaction */
+ u8 block_num;
+ bool request_available;
+ bool response_in_progress;
+ bool busy;
+ /* Response buffer for Multi-part Read Transaction */
+ u8 response_buf[MAX_PAYLOAD_PER_TRANSACTION];
+ struct ssif_msg response;
+ struct ssif_msg request;
+};
+
+static inline struct ssif_bmc_ctx *to_ssif_bmc(struct file *file)
+{
+ return container_of(file->private_data, struct ssif_bmc_ctx, miscdev);
+}
+#endif /* __SSIF_BMC_H__ */
--
2.35.1
On Thu, Mar 10, 2022 at 06:41:18PM +0700, Quan Nguyen wrote:
> From: Dan Carpenter <[email protected]>
>
> The copy_from_user() function returns the number of bytes remaining to
> be copied but we should return -EFAULT here.
>
> Fixes: 501c25b59508 ("ipmi: ssif_bmc: Add SSIF BMC driver")
> Signed-off-by: Dan Carpenter <[email protected]>
> Signed-off-by: Corey Minyard <[email protected]>
> Signed-off-by: Quan Nguyen <[email protected]>
It is nice that you want to keep this patch seperate to give Dan
credits, but I still think it should be merged into patch 1, so the
initial driver is as flawless as it can be. You could give Dan still
credits by mentioning him in the commit message IMO. Dan, would you be
fine with this?
> v6:
> + New add in v6, thanks Dan for the patch [Dan]
>
> drivers/char/ipmi/ssif_bmc.c | 5 ++---
> 1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/char/ipmi/ssif_bmc.c b/drivers/char/ipmi/ssif_bmc.c
> index 62db97773654..91ac2cae756e 100644
> --- a/drivers/char/ipmi/ssif_bmc.c
> +++ b/drivers/char/ipmi/ssif_bmc.c
> @@ -87,9 +87,8 @@ static ssize_t ssif_bmc_write(struct file *file, const char __user *buf, size_t
> if (count > sizeof(struct ssif_msg))
> return -EINVAL;
>
> - ret = copy_from_user(&msg, buf, count);
> - if (ret)
> - return ret;
> + if (copy_from_user(&msg, buf, count))
> + return -EFAULT;
>
> if (!msg.len || count < ssif_msg_len(&msg))
> return -EINVAL;
> --
> 2.35.1
>
Hi Quan,
[...]
> +static void on_read_requested_event(struct ssif_bmc_ctx *ssif_bmc, u8 *val)
> +{
> + if (ssif_bmc->state == SSIF_READY ||
> + ssif_bmc->state == SSIF_START ||
> + ssif_bmc->state == SSIF_REQ_RECVING ||
> + ssif_bmc->state == SSIF_RES_SENDING) {
> + ssif_bmc->state = SSIF_BAD_SMBUS;
> + dev_warn(&ssif_bmc->client->dev,
> + "Warn: %s unexpected READ REQUESTED in state=%s\n",
> + __func__, state_to_string(ssif_bmc->state));
It will print out that the case happens in SSIF_BAD_SMBUS state always
because ssif_bmc->state is already assigned as SSIF_BAD_SMBUS above.
Move the assignment to after the dev_warn printing.
[...]
> +static const struct of_device_id ssif_bmc_match[] = {
> + { .compatible = "ampere,ssif-bmc" },
Does this driver have any Ampere specific handling? If not, it could be
"ssif-bmc" as a generic SSIF driver.
> + { },
> +};
Add 'MODULE_DEVICE_TABLE(of, ssif_bmc_match);'
> +
> +static const struct i2c_device_id ssif_bmc_id[] = {
> + { DEVICE_NAME, 0 },
> + { },
> +};
> +
Remove this blank line.
> +MODULE_DEVICE_TABLE(i2c, ssif_bmc_id);
> +
> +static struct i2c_driver ssif_bmc_driver = {
> + .driver = {
> + .name = DEVICE_NAME,
> + .of_match_table = ssif_bmc_match,
> + },
> + .probe = ssif_bmc_probe,
> + .remove = ssif_bmc_remove,
> + .id_table = ssif_bmc_id,
> +};
> +
Remove this blank line too.
-Jae
> +module_i2c_driver(ssif_bmc_driver);
> +
> +MODULE_AUTHOR("Quan Nguyen <[email protected]>");
> +MODULE_AUTHOR("Chuong Tran <[email protected]>");
> +MODULE_DESCRIPTION("Linux device driver of the BMC IPMI SSIF interface.");
> +MODULE_LICENSE("GPL");
[...]
Added Dan as I have missed Dan's email address in the first place.
My apologize,
- Quan
On 11/03/2022 13:58, Wolfram Sang wrote:
> On Thu, Mar 10, 2022 at 06:41:18PM +0700, Quan Nguyen wrote:
>> From: Dan Carpenter <[email protected]>
>>
>> The copy_from_user() function returns the number of bytes remaining to
>> be copied but we should return -EFAULT here.
>>
>> Fixes: 501c25b59508 ("ipmi: ssif_bmc: Add SSIF BMC driver")
>> Signed-off-by: Dan Carpenter <[email protected]>
>> Signed-off-by: Corey Minyard <[email protected]>
>> Signed-off-by: Quan Nguyen <[email protected]>
>
> It is nice that you want to keep this patch seperate to give Dan
> credits, but I still think it should be merged into patch 1, so the
> initial driver is as flawless as it can be. You could give Dan still
> credits by mentioning him in the commit message IMO. Dan, would you be
> fine with this?
>
>> v6:
>> + New add in v6, thanks Dan for the patch [Dan]
>>
>> drivers/char/ipmi/ssif_bmc.c | 5 ++---
>> 1 file changed, 2 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/char/ipmi/ssif_bmc.c b/drivers/char/ipmi/ssif_bmc.c
>> index 62db97773654..91ac2cae756e 100644
>> --- a/drivers/char/ipmi/ssif_bmc.c
>> +++ b/drivers/char/ipmi/ssif_bmc.c
>> @@ -87,9 +87,8 @@ static ssize_t ssif_bmc_write(struct file *file, const char __user *buf, size_t
>> if (count > sizeof(struct ssif_msg))
>> return -EINVAL;
>>
>> - ret = copy_from_user(&msg, buf, count);
>> - if (ret)
>> - return ret;
>> + if (copy_from_user(&msg, buf, count))
>> + return -EFAULT;
>>
>> if (!msg.len || count < ssif_msg_len(&msg))
>> return -EINVAL;
>> --
>> 2.35.1
>>
On Thu, Mar 17, 2022 at 02:45:19PM +0700, Quan Nguyen wrote:
> Added Dan as I have missed Dan's email address in the first place.
> My apologize,
> - Quan
>
> On 11/03/2022 13:58, Wolfram Sang wrote:
> > On Thu, Mar 10, 2022 at 06:41:18PM +0700, Quan Nguyen wrote:
> > > From: Dan Carpenter <[email protected]>
> > >
> > > The copy_from_user() function returns the number of bytes remaining to
> > > be copied but we should return -EFAULT here.
> > >
> > > Fixes: 501c25b59508 ("ipmi: ssif_bmc: Add SSIF BMC driver")
> > > Signed-off-by: Dan Carpenter <[email protected]>
> > > Signed-off-by: Corey Minyard <[email protected]>
> > > Signed-off-by: Quan Nguyen <[email protected]>
> >
> > It is nice that you want to keep this patch seperate to give Dan
> > credits, but I still think it should be merged into patch 1, so the
> > initial driver is as flawless as it can be. You could give Dan still
> > credits by mentioning him in the commit message IMO. Dan, would you be
> > fine with this?
Yes, that's no problem. Thanks!
regards,
dan carpenter
On 15/03/2022 01:15, Jae Hyun Yoo wrote:
> Hi Quan,
>
> [...]
>
>> +static void on_read_requested_event(struct ssif_bmc_ctx *ssif_bmc, u8
>> *val)
>> +{
>> + if (ssif_bmc->state == SSIF_READY ||
>> + ssif_bmc->state == SSIF_START ||
>> + ssif_bmc->state == SSIF_REQ_RECVING ||
>> + ssif_bmc->state == SSIF_RES_SENDING) {
>> + ssif_bmc->state = SSIF_BAD_SMBUS;
>> + dev_warn(&ssif_bmc->client->dev,
>> + "Warn: %s unexpected READ REQUESTED in state=%s\n",
>> + __func__, state_to_string(ssif_bmc->state));
>
> It will print out that the case happens in SSIF_BAD_SMBUS state always
> because ssif_bmc->state is already assigned as SSIF_BAD_SMBUS above.
> Move the assignment to after the dev_warn printing.
>
> [...]
>
Thanks for pointing this out. Will fix this in next version.
>> +static const struct of_device_id ssif_bmc_match[] = {
>> + { .compatible = "ampere,ssif-bmc" },
>
> Does this driver have any Ampere specific handling? If not, it could be
> "ssif-bmc" as a generic SSIF driver.
>
Will change as you suggested in next version.
>> + { },
>> +};
>
> Add 'MODULE_DEVICE_TABLE(of, ssif_bmc_match);'
>
Will do in next version
>> +
>> +static const struct i2c_device_id ssif_bmc_id[] = {
>> + { DEVICE_NAME, 0 },
>> + { },
>> +};
>> +
>
> Remove this blank line.
>
Will update in next version
>> +MODULE_DEVICE_TABLE(i2c, ssif_bmc_id);
>> +
>> +static struct i2c_driver ssif_bmc_driver = {
>> + .driver = {
>> + .name = DEVICE_NAME,
>> + .of_match_table = ssif_bmc_match,
>> + },
>> + .probe = ssif_bmc_probe,
>> + .remove = ssif_bmc_remove,
>> + .id_table = ssif_bmc_id,
>> +};
>> +
>
> Remove this blank line too.
>
> -Jae
>
Thanks Jae for the review, will update in next version.
- Quan
>> +module_i2c_driver(ssif_bmc_driver);
>> +
>> +MODULE_AUTHOR("Quan Nguyen <[email protected]>");
>> +MODULE_AUTHOR("Chuong Tran <[email protected]>");
>> +MODULE_DESCRIPTION("Linux device driver of the BMC IPMI SSIF
>> interface.");
>> +MODULE_LICENSE("GPL");
>
> [...]