Messages in this thread | | | Date | Mon, 24 Jan 2022 08:17:27 -0600 | Subject | Re: [PATCH v3 2/2] fsi: sbefifo: Implement FSI_SBEFIFO_READ_TIMEOUT_SECONDS ioctl | From | Eddie James <> |
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On 1/20/22 23:38, Joel Stanley wrote: > From: Amitay Isaacs <amitay@ozlabs.org> > > FSI_SBEFIFO_READ_TIMEOUT_SECONDS ioctl sets the read timeout (in > seconds) for the response received by sbefifo device from sbe. The > timeout affects only the read operation on current sbefifo device fd. > > Certain SBE operations can take long time to complete and the default > timeout of 10 seconds might not be sufficient to start receiving > response from SBE. In such cases, allow the timeout to be set to the > maximum of 120 seconds. > > The kernel does not contain the definition of the various SBE > operations, so we must expose an interface to userspace to set the > timeout for the given operation.
Reviewed-by: Eddie James <eajames@linux.ibm.com>
> > Signed-off-by: Amitay Isaacs <amitay@ozlabs.org> > Signed-off-by: Joel Stanley <joel@jms.id.au> > --- > v3: > - Clarify why this is an ioctl and not hardcoded in the kernel > - Add seconds to the name > --- > drivers/fsi/fsi-sbefifo.c | 49 +++++++++++++++++++++++++++++++++++++++ > include/uapi/linux/fsi.h | 14 +++++++++++ > 2 files changed, 63 insertions(+) > > diff --git a/drivers/fsi/fsi-sbefifo.c b/drivers/fsi/fsi-sbefifo.c > index 1e9b326e8f67..f52a912cdf16 100644 > --- a/drivers/fsi/fsi-sbefifo.c > +++ b/drivers/fsi/fsi-sbefifo.c > @@ -32,6 +32,8 @@ > #include <linux/vmalloc.h> > #include <linux/mm.h> > > +#include <uapi/linux/fsi.h> > + > /* > * The SBEFIFO is a pipe-like FSI device for communicating with > * the self boot engine on POWER processors. > @@ -134,6 +136,7 @@ struct sbefifo_user { > void *cmd_page; > void *pending_cmd; > size_t pending_len; > + u32 read_timeout_ms; > }; > > static DEFINE_MUTEX(sbefifo_ffdc_mutex); > @@ -796,6 +799,7 @@ static int sbefifo_user_open(struct inode *inode, struct file *file) > return -ENOMEM; > } > mutex_init(&user->file_lock); > + user->read_timeout_ms = SBEFIFO_TIMEOUT_START_RSP; > > return 0; > } > @@ -838,7 +842,9 @@ static ssize_t sbefifo_user_read(struct file *file, char __user *buf, > rc = mutex_lock_interruptible(&sbefifo->lock); > if (rc) > goto bail; > + 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; > mutex_unlock(&sbefifo->lock); > if (rc < 0) > goto bail; > @@ -928,12 +934,55 @@ static int sbefifo_user_release(struct inode *inode, struct file *file) > return 0; > } > > +static int sbefifo_read_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->read_timeout_ms = SBEFIFO_TIMEOUT_START_RSP; > + dev_dbg(dev, "Timeout reset to %d\n", user->read_timeout_ms); > + return 0; > + } > + > + if (timeout < 10 || timeout > 120) > + return -EINVAL; > + > + user->read_timeout_ms = timeout * 1000; /* user timeout is in sec */ > + > + dev_dbg(dev, "Timeout set to %d\n", user->read_timeout_ms); > + > + return 0; > +} > + > +static long sbefifo_user_ioctl(struct file *file, unsigned int cmd, unsigned long arg) > +{ > + struct sbefifo_user *user = file->private_data; > + int rc = -ENOTTY; > + > + if (!user) > + return -EINVAL; > + > + mutex_lock(&user->file_lock); > + switch (cmd) { > + case FSI_SBEFIFO_READ_TIMEOUT_SECONDS: > + rc = sbefifo_read_timeout(user, (void __user *)arg); > + break; > + } > + mutex_unlock(&user->file_lock); > + return rc; > +} > + > static const struct file_operations sbefifo_fops = { > .owner = THIS_MODULE, > .open = sbefifo_user_open, > .read = sbefifo_user_read, > .write = sbefifo_user_write, > .release = sbefifo_user_release, > + .unlocked_ioctl = sbefifo_user_ioctl, > }; > > static void sbefifo_free(struct device *dev) > diff --git a/include/uapi/linux/fsi.h b/include/uapi/linux/fsi.h > index da577ecd90e7..b2f1977378c7 100644 > --- a/include/uapi/linux/fsi.h > +++ b/include/uapi/linux/fsi.h > @@ -55,4 +55,18 @@ struct scom_access { > #define FSI_SCOM_WRITE _IOWR('s', 0x02, struct scom_access) > #define FSI_SCOM_RESET _IOW('s', 0x03, __u32) > > +/* > + * /dev/sbefifo* ioctl interface > + */ > + > +/** > + * FSI_SBEFIFO_READ_TIMEOUT sets the read timeout for response from SBE. > + * > + * The read timeout is specified in seconds. The minimum value of read > + * timeout is 10 seconds (default) and the maximum value of read timeout is > + * 120 seconds. A read timeout of 0 will reset the value to the default of > + * (10 seconds). > + */ > +#define FSI_SBEFIFO_READ_TIMEOUT_SECONDS _IOW('s', 0x00, __u32) > + > #endif /* _UAPI_LINUX_FSI_H */
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