[PATCH 05/14] fsi: sbefifo: Add configurable in-command timeout

From: Eddie James
Date: Mon Jun 12 2023 - 15:57:40 EST


From: Eddie James <eajames@xxxxxxxxxx>

A new use case for the SBEFIFO requires a long in-command timeout
as the SBE processes each part of the command before clearing the
upstream FIFO for the next part of the command.

Signed-off-by: Eddie James <eajames@xxxxxxxxxxxxx>
---
drivers/fsi/fsi-sbefifo.c | 30 +++++++++++++++++++++++++++++-
include/uapi/linux/fsi.h | 10 ++++++++++
2 files changed, 39 insertions(+), 1 deletion(-)

diff --git a/drivers/fsi/fsi-sbefifo.c b/drivers/fsi/fsi-sbefifo.c
index 42d7c95528d1..5e6a9e08a92d 100644
--- a/drivers/fsi/fsi-sbefifo.c
+++ b/drivers/fsi/fsi-sbefifo.c
@@ -127,6 +127,7 @@ struct sbefifo {
bool dead;
bool async_ffdc;
bool timed_out;
+ u32 timeout_in_cmd_ms;
u32 timeout_start_rsp_ms;
};

@@ -136,6 +137,7 @@ struct sbefifo_user {
void *cmd_page;
void *pending_cmd;
size_t pending_len;
+ u32 cmd_timeout_ms;
u32 read_timeout_ms;
};

@@ -508,7 +510,7 @@ static int sbefifo_send_command(struct sbefifo *sbefifo,
rc = sbefifo_wait(sbefifo, true, &status, timeout);
if (rc < 0)
return rc;
- timeout = msecs_to_jiffies(SBEFIFO_TIMEOUT_IN_CMD);
+ timeout = msecs_to_jiffies(sbefifo->timeout_in_cmd_ms);

vacant = sbefifo_vacant(status);
len = chunk = min(vacant, remaining);
@@ -802,6 +804,7 @@ static int sbefifo_user_open(struct inode *inode, struct file *file)
return -ENOMEM;
}
mutex_init(&user->file_lock);
+ user->cmd_timeout_ms = SBEFIFO_TIMEOUT_IN_CMD;
user->read_timeout_ms = SBEFIFO_TIMEOUT_START_RSP;

return 0;
@@ -845,9 +848,11 @@ static ssize_t sbefifo_user_read(struct file *file, char __user *buf,
rc = mutex_lock_interruptible(&sbefifo->lock);
if (rc)
goto bail;
+ sbefifo->timeout_in_cmd_ms = user->cmd_timeout_ms;
sbefifo->timeout_start_rsp_ms = user->read_timeout_ms;
rc = __sbefifo_submit(sbefifo, user->pending_cmd, cmd_len, &resp_iter);
sbefifo->timeout_start_rsp_ms = SBEFIFO_TIMEOUT_START_RSP;
+ sbefifo->timeout_in_cmd_ms = SBEFIFO_TIMEOUT_IN_CMD;
mutex_unlock(&sbefifo->lock);
if (rc < 0)
goto bail;
@@ -937,6 +942,25 @@ static int sbefifo_user_release(struct inode *inode, struct file *file)
return 0;
}

+static int sbefifo_cmd_timeout(struct sbefifo_user *user, void __user *argp)
+{
+ struct device *dev = &user->sbefifo->dev;
+ u32 timeout;
+
+ if (get_user(timeout, (__u32 __user *)argp))
+ return -EFAULT;
+
+ if (timeout == 0) {
+ user->cmd_timeout_ms = SBEFIFO_TIMEOUT_IN_CMD;
+ dev_dbg(dev, "Command timeout reset to %us\n", user->cmd_timeout_ms / 1000);
+ return 0;
+ }
+
+ user->cmd_timeout_ms = timeout * 1000; /* user timeout is in sec */
+ dev_dbg(dev, "Command timeout set to %us\n", timeout);
+ return 0;
+}
+
static int sbefifo_read_timeout(struct sbefifo_user *user, void __user *argp)
{
struct device *dev = &user->sbefifo->dev;
@@ -971,6 +995,9 @@ static long sbefifo_user_ioctl(struct file *file, unsigned int cmd, unsigned lon

mutex_lock(&user->file_lock);
switch (cmd) {
+ case FSI_SBEFIFO_CMD_TIMEOUT_SECONDS:
+ rc = sbefifo_cmd_timeout(user, (void __user *)arg);
+ break;
case FSI_SBEFIFO_READ_TIMEOUT_SECONDS:
rc = sbefifo_read_timeout(user, (void __user *)arg);
break;
@@ -1025,6 +1052,7 @@ static int sbefifo_probe(struct device *dev)
sbefifo->fsi_dev = fsi_dev;
dev_set_drvdata(dev, sbefifo);
mutex_init(&sbefifo->lock);
+ sbefifo->timeout_in_cmd_ms = SBEFIFO_TIMEOUT_IN_CMD;
sbefifo->timeout_start_rsp_ms = SBEFIFO_TIMEOUT_START_RSP;

/* Create chardev for userspace access */
diff --git a/include/uapi/linux/fsi.h b/include/uapi/linux/fsi.h
index b2f1977378c7..a2e730fc6309 100644
--- a/include/uapi/linux/fsi.h
+++ b/include/uapi/linux/fsi.h
@@ -59,6 +59,16 @@ struct scom_access {
* /dev/sbefifo* ioctl interface
*/

+/**
+ * FSI_SBEFIFO_CMD_TIMEOUT sets the timeout for writing data to the SBEFIFO.
+ *
+ * The command timeout is specified in seconds. The minimum value of command
+ * timeout is 1 seconds (default) and the maximum value of command timeout is
+ * 120 seconds. A command timeout of 0 will reset the value to the default of
+ * 1 seconds.
+ */
+#define FSI_SBEFIFO_CMD_TIMEOUT_SECONDS _IOW('s', 0x01, __u32)
+
/**
* FSI_SBEFIFO_READ_TIMEOUT sets the read timeout for response from SBE.
*
--
2.31.1