From: Logan Gunthorpe
> In order to more successfully script with ntb_tool it's useful to
> have a link file to check the link status so that the script
> doesn't use the other files until the link is up.
>
> This commit adds a 'link' file to the debugfs directory which reads
> boolean (Y or N) depending on the link status. Writing to the file
> change the link state using ntb_link_enable or ntb_link_disable.
>
> A 'link_event' file is also provided so an application can block until
> the link changes to the desired state. If the user writes a 1, it will
> block until the link is up. If the user writes a 0, it will block until
> the link is down.
>
> Signed-off-by: Logan Gunthorpe <log...@deltatee.com>
Acked-by: Allen Hubbe <allen.hu...@emc.com>
> ---
> drivers/ntb/test/ntb_tool.c | 92
> +++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 92 insertions(+)
>
> diff --git a/drivers/ntb/test/ntb_tool.c b/drivers/ntb/test/ntb_tool.c
> index 031723d..b7f4f4e 100644
> --- a/drivers/ntb/test/ntb_tool.c
> +++ b/drivers/ntb/test/ntb_tool.c
> @@ -59,6 +59,12 @@
> *
> * Eg: check if clearing the doorbell mask generates an interrupt.
> *
> + * # Check the link status
> + * root@self# cat $DBG_DIR/link
> + *
> + * # Block until the link is up
> + * root@self# echo Y > $DBG_DIR/link_event
> + *
> * # Set the doorbell mask
> * root@self# echo 's 1' > $DBG_DIR/mask
> *
> @@ -131,6 +137,7 @@ struct tool_mw {
> struct tool_ctx {
> struct ntb_dev *ntb;
> struct dentry *dbgfs;
> + wait_queue_head_t link_wq;
> int mw_count;
> struct tool_mw mws[MAX_MWS];
> };
> @@ -159,6 +166,7 @@ static void tool_link_event(void *ctx)
> dev_dbg(&tc->ntb->dev, "link is %s speed %d width %d\n",
> up ? "up" : "down", speed, width);
>
> + wake_up(&tc->link_wq);
> }
>
> static void tool_db_event(void *ctx, int vec)
> @@ -473,6 +481,83 @@ static TOOL_FOPS_RDWR(tool_peer_spad_fops,
> tool_peer_spad_read,
> tool_peer_spad_write);
>
> +static ssize_t tool_link_read(struct file *filep, char __user *ubuf,
> + size_t size, loff_t *offp)
> +{
> + struct tool_ctx *tc = filep->private_data;
> + char buf[3];
> +
> + buf[0] = ntb_link_is_up(tc->ntb, NULL, NULL) ? 'Y' : 'N';
> + buf[1] = '\n';
> + buf[2] = '\0';
> +
> + return simple_read_from_buffer(ubuf, size, offp, buf, 2);
> +}
> +
> +static ssize_t tool_link_write(struct file *filep, const char __user *ubuf,
> + size_t size, loff_t *offp)
> +{
> + struct tool_ctx *tc = filep->private_data;
> + char buf[32];
> + size_t buf_size;
> + bool val;
> + int rc;
> +
> + buf_size = min(size, (sizeof(buf) - 1));
> + if (copy_from_user(buf, ubuf, buf_size))
> + return -EFAULT;
> +
> + buf[buf_size] = '\0';
> +
> + rc = strtobool(buf, &val);
> + if (rc)
> + return rc;
> +
> + if (val)
> + rc = ntb_link_enable(tc->ntb, NTB_SPEED_AUTO, NTB_WIDTH_AUTO);
> + else
> + rc = ntb_link_disable(tc->ntb);
> +
> + if (rc)
> + return rc;
> +
> + return size;
> +}
> +
> +static TOOL_FOPS_RDWR(tool_link_fops,
> + tool_link_read,
> + tool_link_write);
> +
> +static ssize_t tool_link_event_write(struct file *filep,
> + const char __user *ubuf,
> + size_t size, loff_t *offp)
> +{
> + struct tool_ctx *tc = filep->private_data;
> + char buf[32];
> + size_t buf_size;
> + bool val;
> + int rc;
> +
> + buf_size = min(size, (sizeof(buf) - 1));
> + if (copy_from_user(buf, ubuf, buf_size))
> + return -EFAULT;
> +
> + buf[buf_size] = '\0';
> +
> + rc = strtobool(buf, &val);
> + if (rc)
> + return rc;
> +
> + if (wait_event_interruptible(tc->link_wq,
> + ntb_link_is_up(tc->ntb, NULL, NULL) == val))
> + return -ERESTART;
> +
> + return size;
> +}
> +
> +static TOOL_FOPS_RDWR(tool_link_event_fops,
> + NULL,
> + tool_link_event_write);
>
> static ssize_t tool_mw_read(struct file *filep, char __user *ubuf,
> size_t size, loff_t *offp)
> @@ -793,6 +878,12 @@ static void tool_setup_dbgfs(struct tool_ctx *tc)
> debugfs_create_file("peer_spad", S_IRUSR | S_IWUSR, tc->dbgfs,
> tc, &tool_peer_spad_fops);
>
> + debugfs_create_file("link", S_IRUSR | S_IWUSR, tc->dbgfs,
> + tc, &tool_link_fops);
> +
> + debugfs_create_file("link_event", S_IWUSR, tc->dbgfs,
> + tc, &tool_link_event_fops);
> +
> for (i = 0; i < tc->mw_count; i++) {
> char buf[30];
>
> @@ -825,6 +916,7 @@ static int tool_probe(struct ntb_client *self, struct
> ntb_dev *ntb)
> }
>
> tc->ntb = ntb;
> + init_waitqueue_head(&tc->link_wq);
>
> tc->mw_count = min(ntb_mw_count(tc->ntb), MAX_MWS);
> for (i = 0; i < tc->mw_count; i++) {
> --
> 2.1.4
