Messages in this thread | | | Date | Wed, 15 Dec 2021 06:59:21 +0100 | From | Greg KH <> | Subject | Re: [PATCH 2/2] fsi: sbefifo: implement FSI_SBEFIFO_READ_TIMEOUT ioctl |
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On Wed, Dec 15, 2021 at 11:58:33AM +1100, Amitay Isaacs wrote: > FSI_SBEFIFO_READ_TIMEOUT ioctl sets the read timeout (in seconds) for > the response to *the next* chip-op sent to sbe. The timeout value is > reset to default after the chip-op. The timeout affects only the read() > operation on sbefifo device fd. > > Signed-off-by: Amitay Isaacs <amitay@ozlabs.org> > --- > drivers/fsi/fsi-sbefifo.c | 42 +++++++++++++++++++++++++++++++++++++++ > include/uapi/linux/fsi.h | 6 ++++++ > 2 files changed, 48 insertions(+) > > diff --git a/drivers/fsi/fsi-sbefifo.c b/drivers/fsi/fsi-sbefifo.c > index 9188161f440c..b2654b143b85 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; > + uint32_t read_timeout_ms;
u32 please. uint32_t is a userspace thing.
> }; > > 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 +842,11 @@ static ssize_t sbefifo_user_read(struct file *file, char __user *buf, > rc = mutex_lock_interruptible(&sbefifo->lock); > if (rc) > goto bail; > + sbefifo->timeout_start_rsp_ms = user->read_timeout_ms; > rc = __sbefifo_submit(sbefifo, user->pending_cmd, cmd_len, &resp_iter); > + /* Reset the read timeout after a single chip-op */ > + sbefifo->timeout_start_rsp_ms = SBEFIFO_TIMEOUT_START_RSP; > + user->read_timeout_ms = SBEFIFO_TIMEOUT_START_RSP; > mutex_unlock(&sbefifo->lock); > if (rc < 0) > goto bail; > @@ -847,6 +855,7 @@ static ssize_t sbefifo_user_read(struct file *file, char __user *buf, > rc = len - iov_iter_count(&resp_iter); > bail: > sbefifo_release_command(user); > + user->read_timeout_ms = 0; > mutex_unlock(&user->file_lock); > return rc; > } > @@ -928,12 +937,45 @@ 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) > +{ > + uint32_t timeout;
u32
> + > + if (get_user(timeout, (__u32 __user *)argp)) > + return -EFAULT; > + if (timeout < 10 || timeout > 120) > + return -EINVAL; > + > + user->read_timeout_ms = timeout * 1000; /* user timeout is in sec */ > + return 0; > +} > + > +static long sbefifo_user_ioctl(struct file *file, unsigned int cmd, unsigned long arg) > +{ > + struct sbefifo_user *user = file->private_data; > + void __user **argp = (void __user *)arg; > + int rc = -ENOTTY; > + > + if (!user) > + return -EINVAL; > + > + mutex_lock(&user->file_lock); > + switch (cmd) { > + case FSI_SBEFIFO_READ_TIMEOUT: > + rc = sbefifo_read_timeout(user, argp); > + break; > + } > + mutex_unlock(&user->file_lock); > + return rc; > +}
Why do you have to have an ioctl for a single thing like this?
> + > 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..3e00874ace22 100644 > --- a/include/uapi/linux/fsi.h > +++ b/include/uapi/linux/fsi.h > @@ -55,4 +55,10 @@ 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 > + */ > + > +#define FSI_SBEFIFO_READ_TIMEOUT _IOW('s', 0x00, __u32)
Where have you documented this new user/kernel api?
And why not just use a sysfs file for something like this?
thanks,
greg k-h
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