* [PATCH] NTB: ntb_transport: Use seq_file for QP stats debugfs
@ 2025-12-17 8:19 Koichiro Den
2026-01-06 16:37 ` Dave Jiang
0 siblings, 1 reply; 5+ messages in thread
From: Koichiro Den @ 2025-12-17 8:19 UTC (permalink / raw)
To: ntb, linux-kernel; +Cc: jdmason, dave.jiang, allenbh, Frank.Li
The ./qp*/stats debugfs file for each NTB transport QP is currently
implemented with a hand-crafted kmalloc() buffer and a series of
scnprintf() calls. This is a pre-seq_file style pattern and makes future
extensions easy to truncate.
Convert the stats file to use the seq_file helpers via
DEFINE_SHOW_ATTRIBUTE(), which simplifies the code and lets the seq_file
core handle buffering and partial reads.
While touching this area, fix a bug in the per-QP debugfs directory
naming: the buffer used for "qp%d" was only 4 bytes, which truncates
names like "qp10" to "qp1" and causes multiple queues to share the same
directory. Enlarge the buffer and use sizeof() to avoid truncation.
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Koichiro Den <den@valinux.co.jp>
---
Note: This patch is split out from the following series, where it was
originally included as a preparatory change (refactor + small fix):
https://lore.kernel.org/all/aS3xe0CNHeIMUu7P@lizhi-Precision-Tower-5810/
---
drivers/ntb/ntb_transport.c | 136 +++++++++++-------------------------
1 file changed, 41 insertions(+), 95 deletions(-)
diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c
index eb875e3db2e3..d5a544bf8fd6 100644
--- a/drivers/ntb/ntb_transport.c
+++ b/drivers/ntb/ntb_transport.c
@@ -57,6 +57,7 @@
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/slab.h>
+#include <linux/seq_file.h>
#include <linux/types.h>
#include <linux/uaccess.h>
#include <linux/mutex.h>
@@ -466,104 +467,49 @@ void ntb_transport_unregister_client(struct ntb_transport_client *drv)
}
EXPORT_SYMBOL_GPL(ntb_transport_unregister_client);
-static ssize_t debugfs_read(struct file *filp, char __user *ubuf, size_t count,
- loff_t *offp)
+static int ntb_qp_debugfs_stats_show(struct seq_file *s, void *v)
{
- struct ntb_transport_qp *qp;
- char *buf;
- ssize_t ret, out_offset, out_count;
-
- qp = filp->private_data;
+ struct ntb_transport_qp *qp = s->private;
if (!qp || !qp->link_is_up)
return 0;
- out_count = 1000;
-
- buf = kmalloc(out_count, GFP_KERNEL);
- if (!buf)
- return -ENOMEM;
+ seq_puts(s, "\nNTB QP stats:\n\n");
+
+ seq_printf(s, "rx_bytes - \t%llu\n", qp->rx_bytes);
+ seq_printf(s, "rx_pkts - \t%llu\n", qp->rx_pkts);
+ seq_printf(s, "rx_memcpy - \t%llu\n", qp->rx_memcpy);
+ seq_printf(s, "rx_async - \t%llu\n", qp->rx_async);
+ seq_printf(s, "rx_ring_empty - %llu\n", qp->rx_ring_empty);
+ seq_printf(s, "rx_err_no_buf - %llu\n", qp->rx_err_no_buf);
+ seq_printf(s, "rx_err_oflow - \t%llu\n", qp->rx_err_oflow);
+ seq_printf(s, "rx_err_ver - \t%llu\n", qp->rx_err_ver);
+ seq_printf(s, "rx_buff - \t0x%p\n", qp->rx_buff);
+ seq_printf(s, "rx_index - \t%u\n", qp->rx_index);
+ seq_printf(s, "rx_max_entry - \t%u\n", qp->rx_max_entry);
+ seq_printf(s, "rx_alloc_entry - \t%u\n\n", qp->rx_alloc_entry);
+
+ seq_printf(s, "tx_bytes - \t%llu\n", qp->tx_bytes);
+ seq_printf(s, "tx_pkts - \t%llu\n", qp->tx_pkts);
+ seq_printf(s, "tx_memcpy - \t%llu\n", qp->tx_memcpy);
+ seq_printf(s, "tx_async - \t%llu\n", qp->tx_async);
+ seq_printf(s, "tx_ring_full - \t%llu\n", qp->tx_ring_full);
+ seq_printf(s, "tx_err_no_buf - %llu\n", qp->tx_err_no_buf);
+ seq_printf(s, "tx_mw - \t0x%p\n", qp->tx_mw);
+ seq_printf(s, "tx_index (H) - \t%u\n", qp->tx_index);
+ seq_printf(s, "RRI (T) - \t%u\n", qp->remote_rx_info->entry);
+ seq_printf(s, "tx_max_entry - \t%u\n", qp->tx_max_entry);
+ seq_printf(s, "free tx - \t%u\n", ntb_transport_tx_free_entry(qp));
+ seq_putc(s, '\n');
+
+ seq_printf(s, "Using TX DMA - \t%s\n", qp->tx_dma_chan ? "Yes" : "No");
+ seq_printf(s, "Using RX DMA - \t%s\n", qp->rx_dma_chan ? "Yes" : "No");
+ seq_printf(s, "QP Link - \t%s\n", qp->link_is_up ? "Up" : "Down");
+ seq_putc(s, '\n');
- out_offset = 0;
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "\nNTB QP stats:\n\n");
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "rx_bytes - \t%llu\n", qp->rx_bytes);
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "rx_pkts - \t%llu\n", qp->rx_pkts);
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "rx_memcpy - \t%llu\n", qp->rx_memcpy);
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "rx_async - \t%llu\n", qp->rx_async);
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "rx_ring_empty - %llu\n", qp->rx_ring_empty);
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "rx_err_no_buf - %llu\n", qp->rx_err_no_buf);
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "rx_err_oflow - \t%llu\n", qp->rx_err_oflow);
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "rx_err_ver - \t%llu\n", qp->rx_err_ver);
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "rx_buff - \t0x%p\n", qp->rx_buff);
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "rx_index - \t%u\n", qp->rx_index);
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "rx_max_entry - \t%u\n", qp->rx_max_entry);
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "rx_alloc_entry - \t%u\n\n", qp->rx_alloc_entry);
-
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "tx_bytes - \t%llu\n", qp->tx_bytes);
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "tx_pkts - \t%llu\n", qp->tx_pkts);
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "tx_memcpy - \t%llu\n", qp->tx_memcpy);
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "tx_async - \t%llu\n", qp->tx_async);
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "tx_ring_full - \t%llu\n", qp->tx_ring_full);
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "tx_err_no_buf - %llu\n", qp->tx_err_no_buf);
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "tx_mw - \t0x%p\n", qp->tx_mw);
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "tx_index (H) - \t%u\n", qp->tx_index);
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "RRI (T) - \t%u\n",
- qp->remote_rx_info->entry);
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "tx_max_entry - \t%u\n", qp->tx_max_entry);
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "free tx - \t%u\n",
- ntb_transport_tx_free_entry(qp));
-
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "\n");
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "Using TX DMA - \t%s\n",
- qp->tx_dma_chan ? "Yes" : "No");
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "Using RX DMA - \t%s\n",
- qp->rx_dma_chan ? "Yes" : "No");
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "QP Link - \t%s\n",
- qp->link_is_up ? "Up" : "Down");
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "\n");
-
- if (out_offset > out_count)
- out_offset = out_count;
-
- ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
- kfree(buf);
- return ret;
-}
-
-static const struct file_operations ntb_qp_debugfs_stats = {
- .owner = THIS_MODULE,
- .open = simple_open,
- .read = debugfs_read,
-};
+ return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(ntb_qp_debugfs_stats);
static void ntb_list_add(spinlock_t *lock, struct list_head *entry,
struct list_head *list)
@@ -1236,15 +1182,15 @@ static int ntb_transport_init_queue(struct ntb_transport_ctx *nt,
qp->tx_max_entry = tx_size / qp->tx_max_frame;
if (nt->debugfs_node_dir) {
- char debugfs_name[4];
+ char debugfs_name[8];
- snprintf(debugfs_name, 4, "qp%d", qp_num);
+ snprintf(debugfs_name, sizeof(debugfs_name), "qp%d", qp_num);
qp->debugfs_dir = debugfs_create_dir(debugfs_name,
nt->debugfs_node_dir);
qp->debugfs_stats = debugfs_create_file("stats", S_IRUSR,
qp->debugfs_dir, qp,
- &ntb_qp_debugfs_stats);
+ &ntb_qp_debugfs_stats_fops);
} else {
qp->debugfs_dir = NULL;
qp->debugfs_stats = NULL;
--
2.51.0
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH] NTB: ntb_transport: Use seq_file for QP stats debugfs
2025-12-17 8:19 [PATCH] NTB: ntb_transport: Use seq_file for QP stats debugfs Koichiro Den
@ 2026-01-06 16:37 ` Dave Jiang
2026-01-07 4:29 ` Koichiro Den
0 siblings, 1 reply; 5+ messages in thread
From: Dave Jiang @ 2026-01-06 16:37 UTC (permalink / raw)
To: Koichiro Den, ntb, linux-kernel; +Cc: jdmason, allenbh, Frank.Li
On 12/17/25 1:19 AM, Koichiro Den wrote:
> The ./qp*/stats debugfs file for each NTB transport QP is currently
> implemented with a hand-crafted kmalloc() buffer and a series of
> scnprintf() calls. This is a pre-seq_file style pattern and makes future
> extensions easy to truncate.
>
> Convert the stats file to use the seq_file helpers via
> DEFINE_SHOW_ATTRIBUTE(), which simplifies the code and lets the seq_file
> core handle buffering and partial reads.
>
> While touching this area, fix a bug in the per-QP debugfs directory
> naming: the buffer used for "qp%d" was only 4 bytes, which truncates
> names like "qp10" to "qp1" and causes multiple queues to share the same
> directory. Enlarge the buffer and use sizeof() to avoid truncation.
>
> Reviewed-by: Frank Li <Frank.Li@nxp.com>
> Signed-off-by: Koichiro Den <den@valinux.co.jp>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Thanks for the improvement!
Can you please split out the bug fix and add a Fixes tag so it can go to stable kernels? Thanks!
> ---
> Note: This patch is split out from the following series, where it was
> originally included as a preparatory change (refactor + small fix):
> https://lore.kernel.org/all/aS3xe0CNHeIMUu7P@lizhi-Precision-Tower-5810/
> ---
> drivers/ntb/ntb_transport.c | 136 +++++++++++-------------------------
> 1 file changed, 41 insertions(+), 95 deletions(-)
>
> diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c
> index eb875e3db2e3..d5a544bf8fd6 100644
> --- a/drivers/ntb/ntb_transport.c
> +++ b/drivers/ntb/ntb_transport.c
> @@ -57,6 +57,7 @@
> #include <linux/module.h>
> #include <linux/pci.h>
> #include <linux/slab.h>
> +#include <linux/seq_file.h>
> #include <linux/types.h>
> #include <linux/uaccess.h>
> #include <linux/mutex.h>
> @@ -466,104 +467,49 @@ void ntb_transport_unregister_client(struct ntb_transport_client *drv)
> }
> EXPORT_SYMBOL_GPL(ntb_transport_unregister_client);
>
> -static ssize_t debugfs_read(struct file *filp, char __user *ubuf, size_t count,
> - loff_t *offp)
> +static int ntb_qp_debugfs_stats_show(struct seq_file *s, void *v)
> {
> - struct ntb_transport_qp *qp;
> - char *buf;
> - ssize_t ret, out_offset, out_count;
> -
> - qp = filp->private_data;
> + struct ntb_transport_qp *qp = s->private;
>
> if (!qp || !qp->link_is_up)
> return 0;
>
> - out_count = 1000;
> -
> - buf = kmalloc(out_count, GFP_KERNEL);
> - if (!buf)
> - return -ENOMEM;
> + seq_puts(s, "\nNTB QP stats:\n\n");
> +
> + seq_printf(s, "rx_bytes - \t%llu\n", qp->rx_bytes);
> + seq_printf(s, "rx_pkts - \t%llu\n", qp->rx_pkts);
> + seq_printf(s, "rx_memcpy - \t%llu\n", qp->rx_memcpy);
> + seq_printf(s, "rx_async - \t%llu\n", qp->rx_async);
> + seq_printf(s, "rx_ring_empty - %llu\n", qp->rx_ring_empty);
> + seq_printf(s, "rx_err_no_buf - %llu\n", qp->rx_err_no_buf);
> + seq_printf(s, "rx_err_oflow - \t%llu\n", qp->rx_err_oflow);
> + seq_printf(s, "rx_err_ver - \t%llu\n", qp->rx_err_ver);
> + seq_printf(s, "rx_buff - \t0x%p\n", qp->rx_buff);
> + seq_printf(s, "rx_index - \t%u\n", qp->rx_index);
> + seq_printf(s, "rx_max_entry - \t%u\n", qp->rx_max_entry);
> + seq_printf(s, "rx_alloc_entry - \t%u\n\n", qp->rx_alloc_entry);
> +
> + seq_printf(s, "tx_bytes - \t%llu\n", qp->tx_bytes);
> + seq_printf(s, "tx_pkts - \t%llu\n", qp->tx_pkts);
> + seq_printf(s, "tx_memcpy - \t%llu\n", qp->tx_memcpy);
> + seq_printf(s, "tx_async - \t%llu\n", qp->tx_async);
> + seq_printf(s, "tx_ring_full - \t%llu\n", qp->tx_ring_full);
> + seq_printf(s, "tx_err_no_buf - %llu\n", qp->tx_err_no_buf);
> + seq_printf(s, "tx_mw - \t0x%p\n", qp->tx_mw);
> + seq_printf(s, "tx_index (H) - \t%u\n", qp->tx_index);
> + seq_printf(s, "RRI (T) - \t%u\n", qp->remote_rx_info->entry);
> + seq_printf(s, "tx_max_entry - \t%u\n", qp->tx_max_entry);
> + seq_printf(s, "free tx - \t%u\n", ntb_transport_tx_free_entry(qp));
> + seq_putc(s, '\n');
> +
> + seq_printf(s, "Using TX DMA - \t%s\n", qp->tx_dma_chan ? "Yes" : "No");
> + seq_printf(s, "Using RX DMA - \t%s\n", qp->rx_dma_chan ? "Yes" : "No");
> + seq_printf(s, "QP Link - \t%s\n", qp->link_is_up ? "Up" : "Down");
> + seq_putc(s, '\n');
>
> - out_offset = 0;
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "\nNTB QP stats:\n\n");
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "rx_bytes - \t%llu\n", qp->rx_bytes);
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "rx_pkts - \t%llu\n", qp->rx_pkts);
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "rx_memcpy - \t%llu\n", qp->rx_memcpy);
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "rx_async - \t%llu\n", qp->rx_async);
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "rx_ring_empty - %llu\n", qp->rx_ring_empty);
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "rx_err_no_buf - %llu\n", qp->rx_err_no_buf);
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "rx_err_oflow - \t%llu\n", qp->rx_err_oflow);
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "rx_err_ver - \t%llu\n", qp->rx_err_ver);
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "rx_buff - \t0x%p\n", qp->rx_buff);
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "rx_index - \t%u\n", qp->rx_index);
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "rx_max_entry - \t%u\n", qp->rx_max_entry);
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "rx_alloc_entry - \t%u\n\n", qp->rx_alloc_entry);
> -
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "tx_bytes - \t%llu\n", qp->tx_bytes);
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "tx_pkts - \t%llu\n", qp->tx_pkts);
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "tx_memcpy - \t%llu\n", qp->tx_memcpy);
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "tx_async - \t%llu\n", qp->tx_async);
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "tx_ring_full - \t%llu\n", qp->tx_ring_full);
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "tx_err_no_buf - %llu\n", qp->tx_err_no_buf);
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "tx_mw - \t0x%p\n", qp->tx_mw);
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "tx_index (H) - \t%u\n", qp->tx_index);
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "RRI (T) - \t%u\n",
> - qp->remote_rx_info->entry);
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "tx_max_entry - \t%u\n", qp->tx_max_entry);
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "free tx - \t%u\n",
> - ntb_transport_tx_free_entry(qp));
> -
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "\n");
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "Using TX DMA - \t%s\n",
> - qp->tx_dma_chan ? "Yes" : "No");
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "Using RX DMA - \t%s\n",
> - qp->rx_dma_chan ? "Yes" : "No");
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "QP Link - \t%s\n",
> - qp->link_is_up ? "Up" : "Down");
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "\n");
> -
> - if (out_offset > out_count)
> - out_offset = out_count;
> -
> - ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
> - kfree(buf);
> - return ret;
> -}
> -
> -static const struct file_operations ntb_qp_debugfs_stats = {
> - .owner = THIS_MODULE,
> - .open = simple_open,
> - .read = debugfs_read,
> -};
> + return 0;
> +}
> +DEFINE_SHOW_ATTRIBUTE(ntb_qp_debugfs_stats);
>
> static void ntb_list_add(spinlock_t *lock, struct list_head *entry,
> struct list_head *list)
> @@ -1236,15 +1182,15 @@ static int ntb_transport_init_queue(struct ntb_transport_ctx *nt,
> qp->tx_max_entry = tx_size / qp->tx_max_frame;
>
> if (nt->debugfs_node_dir) {
> - char debugfs_name[4];
> + char debugfs_name[8];
>
> - snprintf(debugfs_name, 4, "qp%d", qp_num);
> + snprintf(debugfs_name, sizeof(debugfs_name), "qp%d", qp_num);
> qp->debugfs_dir = debugfs_create_dir(debugfs_name,
> nt->debugfs_node_dir);
>
> qp->debugfs_stats = debugfs_create_file("stats", S_IRUSR,
> qp->debugfs_dir, qp,
> - &ntb_qp_debugfs_stats);
> + &ntb_qp_debugfs_stats_fops);
> } else {
> qp->debugfs_dir = NULL;
> qp->debugfs_stats = NULL;
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH] NTB: ntb_transport: Use seq_file for QP stats debugfs
2026-01-06 16:37 ` Dave Jiang
@ 2026-01-07 4:29 ` Koichiro Den
0 siblings, 0 replies; 5+ messages in thread
From: Koichiro Den @ 2026-01-07 4:29 UTC (permalink / raw)
To: Dave Jiang; +Cc: ntb, linux-kernel, jdmason, allenbh, Frank.Li
On Tue, Jan 06, 2026 at 09:37:06AM -0700, Dave Jiang wrote:
>
>
> On 12/17/25 1:19 AM, Koichiro Den wrote:
> > The ./qp*/stats debugfs file for each NTB transport QP is currently
> > implemented with a hand-crafted kmalloc() buffer and a series of
> > scnprintf() calls. This is a pre-seq_file style pattern and makes future
> > extensions easy to truncate.
> >
> > Convert the stats file to use the seq_file helpers via
> > DEFINE_SHOW_ATTRIBUTE(), which simplifies the code and lets the seq_file
> > core handle buffering and partial reads.
> >
> > While touching this area, fix a bug in the per-QP debugfs directory
> > naming: the buffer used for "qp%d" was only 4 bytes, which truncates
> > names like "qp10" to "qp1" and causes multiple queues to share the same
> > directory. Enlarge the buffer and use sizeof() to avoid truncation.
> >
> > Reviewed-by: Frank Li <Frank.Li@nxp.com>
> > Signed-off-by: Koichiro Den <den@valinux.co.jp>
>
> Reviewed-by: Dave Jiang <dave.jiang@intel.com>
>
> Thanks for the improvement!
>
> Can you please split out the bug fix and add a Fixes tag so it can go to stable kernels? Thanks!
I have split it out and sent v2 here:
https://lore.kernel.org/all/20260107042458.1987818-1-den@valinux.co.jp/
Thanks for the review,
Koichiro
>
> > ---
> > Note: This patch is split out from the following series, where it was
> > originally included as a preparatory change (refactor + small fix):
> > https://lore.kernel.org/all/aS3xe0CNHeIMUu7P@lizhi-Precision-Tower-5810/
> > ---
> > drivers/ntb/ntb_transport.c | 136 +++++++++++-------------------------
> > 1 file changed, 41 insertions(+), 95 deletions(-)
> >
> > diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c
> > index eb875e3db2e3..d5a544bf8fd6 100644
> > --- a/drivers/ntb/ntb_transport.c
> > +++ b/drivers/ntb/ntb_transport.c
> > @@ -57,6 +57,7 @@
> > #include <linux/module.h>
> > #include <linux/pci.h>
> > #include <linux/slab.h>
> > +#include <linux/seq_file.h>
> > #include <linux/types.h>
> > #include <linux/uaccess.h>
> > #include <linux/mutex.h>
> > @@ -466,104 +467,49 @@ void ntb_transport_unregister_client(struct ntb_transport_client *drv)
> > }
> > EXPORT_SYMBOL_GPL(ntb_transport_unregister_client);
> >
> > -static ssize_t debugfs_read(struct file *filp, char __user *ubuf, size_t count,
> > - loff_t *offp)
> > +static int ntb_qp_debugfs_stats_show(struct seq_file *s, void *v)
> > {
> > - struct ntb_transport_qp *qp;
> > - char *buf;
> > - ssize_t ret, out_offset, out_count;
> > -
> > - qp = filp->private_data;
> > + struct ntb_transport_qp *qp = s->private;
> >
> > if (!qp || !qp->link_is_up)
> > return 0;
> >
> > - out_count = 1000;
> > -
> > - buf = kmalloc(out_count, GFP_KERNEL);
> > - if (!buf)
> > - return -ENOMEM;
> > + seq_puts(s, "\nNTB QP stats:\n\n");
> > +
> > + seq_printf(s, "rx_bytes - \t%llu\n", qp->rx_bytes);
> > + seq_printf(s, "rx_pkts - \t%llu\n", qp->rx_pkts);
> > + seq_printf(s, "rx_memcpy - \t%llu\n", qp->rx_memcpy);
> > + seq_printf(s, "rx_async - \t%llu\n", qp->rx_async);
> > + seq_printf(s, "rx_ring_empty - %llu\n", qp->rx_ring_empty);
> > + seq_printf(s, "rx_err_no_buf - %llu\n", qp->rx_err_no_buf);
> > + seq_printf(s, "rx_err_oflow - \t%llu\n", qp->rx_err_oflow);
> > + seq_printf(s, "rx_err_ver - \t%llu\n", qp->rx_err_ver);
> > + seq_printf(s, "rx_buff - \t0x%p\n", qp->rx_buff);
> > + seq_printf(s, "rx_index - \t%u\n", qp->rx_index);
> > + seq_printf(s, "rx_max_entry - \t%u\n", qp->rx_max_entry);
> > + seq_printf(s, "rx_alloc_entry - \t%u\n\n", qp->rx_alloc_entry);
> > +
> > + seq_printf(s, "tx_bytes - \t%llu\n", qp->tx_bytes);
> > + seq_printf(s, "tx_pkts - \t%llu\n", qp->tx_pkts);
> > + seq_printf(s, "tx_memcpy - \t%llu\n", qp->tx_memcpy);
> > + seq_printf(s, "tx_async - \t%llu\n", qp->tx_async);
> > + seq_printf(s, "tx_ring_full - \t%llu\n", qp->tx_ring_full);
> > + seq_printf(s, "tx_err_no_buf - %llu\n", qp->tx_err_no_buf);
> > + seq_printf(s, "tx_mw - \t0x%p\n", qp->tx_mw);
> > + seq_printf(s, "tx_index (H) - \t%u\n", qp->tx_index);
> > + seq_printf(s, "RRI (T) - \t%u\n", qp->remote_rx_info->entry);
> > + seq_printf(s, "tx_max_entry - \t%u\n", qp->tx_max_entry);
> > + seq_printf(s, "free tx - \t%u\n", ntb_transport_tx_free_entry(qp));
> > + seq_putc(s, '\n');
> > +
> > + seq_printf(s, "Using TX DMA - \t%s\n", qp->tx_dma_chan ? "Yes" : "No");
> > + seq_printf(s, "Using RX DMA - \t%s\n", qp->rx_dma_chan ? "Yes" : "No");
> > + seq_printf(s, "QP Link - \t%s\n", qp->link_is_up ? "Up" : "Down");
> > + seq_putc(s, '\n');
> >
> > - out_offset = 0;
> > - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> > - "\nNTB QP stats:\n\n");
> > - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> > - "rx_bytes - \t%llu\n", qp->rx_bytes);
> > - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> > - "rx_pkts - \t%llu\n", qp->rx_pkts);
> > - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> > - "rx_memcpy - \t%llu\n", qp->rx_memcpy);
> > - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> > - "rx_async - \t%llu\n", qp->rx_async);
> > - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> > - "rx_ring_empty - %llu\n", qp->rx_ring_empty);
> > - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> > - "rx_err_no_buf - %llu\n", qp->rx_err_no_buf);
> > - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> > - "rx_err_oflow - \t%llu\n", qp->rx_err_oflow);
> > - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> > - "rx_err_ver - \t%llu\n", qp->rx_err_ver);
> > - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> > - "rx_buff - \t0x%p\n", qp->rx_buff);
> > - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> > - "rx_index - \t%u\n", qp->rx_index);
> > - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> > - "rx_max_entry - \t%u\n", qp->rx_max_entry);
> > - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> > - "rx_alloc_entry - \t%u\n\n", qp->rx_alloc_entry);
> > -
> > - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> > - "tx_bytes - \t%llu\n", qp->tx_bytes);
> > - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> > - "tx_pkts - \t%llu\n", qp->tx_pkts);
> > - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> > - "tx_memcpy - \t%llu\n", qp->tx_memcpy);
> > - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> > - "tx_async - \t%llu\n", qp->tx_async);
> > - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> > - "tx_ring_full - \t%llu\n", qp->tx_ring_full);
> > - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> > - "tx_err_no_buf - %llu\n", qp->tx_err_no_buf);
> > - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> > - "tx_mw - \t0x%p\n", qp->tx_mw);
> > - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> > - "tx_index (H) - \t%u\n", qp->tx_index);
> > - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> > - "RRI (T) - \t%u\n",
> > - qp->remote_rx_info->entry);
> > - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> > - "tx_max_entry - \t%u\n", qp->tx_max_entry);
> > - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> > - "free tx - \t%u\n",
> > - ntb_transport_tx_free_entry(qp));
> > -
> > - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> > - "\n");
> > - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> > - "Using TX DMA - \t%s\n",
> > - qp->tx_dma_chan ? "Yes" : "No");
> > - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> > - "Using RX DMA - \t%s\n",
> > - qp->rx_dma_chan ? "Yes" : "No");
> > - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> > - "QP Link - \t%s\n",
> > - qp->link_is_up ? "Up" : "Down");
> > - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> > - "\n");
> > -
> > - if (out_offset > out_count)
> > - out_offset = out_count;
> > -
> > - ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
> > - kfree(buf);
> > - return ret;
> > -}
> > -
> > -static const struct file_operations ntb_qp_debugfs_stats = {
> > - .owner = THIS_MODULE,
> > - .open = simple_open,
> > - .read = debugfs_read,
> > -};
> > + return 0;
> > +}
> > +DEFINE_SHOW_ATTRIBUTE(ntb_qp_debugfs_stats);
> >
> > static void ntb_list_add(spinlock_t *lock, struct list_head *entry,
> > struct list_head *list)
> > @@ -1236,15 +1182,15 @@ static int ntb_transport_init_queue(struct ntb_transport_ctx *nt,
> > qp->tx_max_entry = tx_size / qp->tx_max_frame;
> >
> > if (nt->debugfs_node_dir) {
> > - char debugfs_name[4];
> > + char debugfs_name[8];
> >
> > - snprintf(debugfs_name, 4, "qp%d", qp_num);
> > + snprintf(debugfs_name, sizeof(debugfs_name), "qp%d", qp_num);
> > qp->debugfs_dir = debugfs_create_dir(debugfs_name,
> > nt->debugfs_node_dir);
> >
> > qp->debugfs_stats = debugfs_create_file("stats", S_IRUSR,
> > qp->debugfs_dir, qp,
> > - &ntb_qp_debugfs_stats);
> > + &ntb_qp_debugfs_stats_fops);
> > } else {
> > qp->debugfs_dir = NULL;
> > qp->debugfs_stats = NULL;
>
^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH] NTB: ntb_transport: Use seq_file for QP stats debugfs
@ 2025-12-17 14:18 Koichiro Den
2025-12-18 4:46 ` Koichiro Den
0 siblings, 1 reply; 5+ messages in thread
From: Koichiro Den @ 2025-12-17 14:18 UTC (permalink / raw)
To: ntb; +Cc: jdmason, dave.jiang, allenbh, Frank.Li, linux-kernel
The ./qp*/stats debugfs file for each NTB transport QP is currently
implemented with a hand-crafted kmalloc() buffer and a series of
scnprintf() calls. This is a pre-seq_file style pattern and makes future
extensions easy to truncate.
Convert the stats file to use the seq_file helpers via
DEFINE_SHOW_ATTRIBUTE(), which simplifies the code and lets the seq_file
core handle buffering and partial reads.
While touching this area, fix a bug in the per-QP debugfs directory
naming: the buffer used for "qp%d" was only 4 bytes, which truncates
names like "qp10" to "qp1" and causes multiple queues to share the same
directory. Enlarge the buffer and use sizeof() to avoid truncation.
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Koichiro Den <den@valinux.co.jp>
---
Note: This patch is split out from the following series, where it was
originally included as a preparatory change (refactor + small fix):
https://lore.kernel.org/all/aS3xe0CNHeIMUu7P@lizhi-Precision-Tower-5810/
drivers/ntb/ntb_transport.c | 136 +++++++++++-------------------------
1 file changed, 41 insertions(+), 95 deletions(-)
diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c
index eb875e3db2e3..d5a544bf8fd6 100644
--- a/drivers/ntb/ntb_transport.c
+++ b/drivers/ntb/ntb_transport.c
@@ -57,6 +57,7 @@
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/slab.h>
+#include <linux/seq_file.h>
#include <linux/types.h>
#include <linux/uaccess.h>
#include <linux/mutex.h>
@@ -466,104 +467,49 @@ void ntb_transport_unregister_client(struct ntb_transport_client *drv)
}
EXPORT_SYMBOL_GPL(ntb_transport_unregister_client);
-static ssize_t debugfs_read(struct file *filp, char __user *ubuf, size_t count,
- loff_t *offp)
+static int ntb_qp_debugfs_stats_show(struct seq_file *s, void *v)
{
- struct ntb_transport_qp *qp;
- char *buf;
- ssize_t ret, out_offset, out_count;
-
- qp = filp->private_data;
+ struct ntb_transport_qp *qp = s->private;
if (!qp || !qp->link_is_up)
return 0;
- out_count = 1000;
-
- buf = kmalloc(out_count, GFP_KERNEL);
- if (!buf)
- return -ENOMEM;
+ seq_puts(s, "\nNTB QP stats:\n\n");
+
+ seq_printf(s, "rx_bytes - \t%llu\n", qp->rx_bytes);
+ seq_printf(s, "rx_pkts - \t%llu\n", qp->rx_pkts);
+ seq_printf(s, "rx_memcpy - \t%llu\n", qp->rx_memcpy);
+ seq_printf(s, "rx_async - \t%llu\n", qp->rx_async);
+ seq_printf(s, "rx_ring_empty - %llu\n", qp->rx_ring_empty);
+ seq_printf(s, "rx_err_no_buf - %llu\n", qp->rx_err_no_buf);
+ seq_printf(s, "rx_err_oflow - \t%llu\n", qp->rx_err_oflow);
+ seq_printf(s, "rx_err_ver - \t%llu\n", qp->rx_err_ver);
+ seq_printf(s, "rx_buff - \t0x%p\n", qp->rx_buff);
+ seq_printf(s, "rx_index - \t%u\n", qp->rx_index);
+ seq_printf(s, "rx_max_entry - \t%u\n", qp->rx_max_entry);
+ seq_printf(s, "rx_alloc_entry - \t%u\n\n", qp->rx_alloc_entry);
+
+ seq_printf(s, "tx_bytes - \t%llu\n", qp->tx_bytes);
+ seq_printf(s, "tx_pkts - \t%llu\n", qp->tx_pkts);
+ seq_printf(s, "tx_memcpy - \t%llu\n", qp->tx_memcpy);
+ seq_printf(s, "tx_async - \t%llu\n", qp->tx_async);
+ seq_printf(s, "tx_ring_full - \t%llu\n", qp->tx_ring_full);
+ seq_printf(s, "tx_err_no_buf - %llu\n", qp->tx_err_no_buf);
+ seq_printf(s, "tx_mw - \t0x%p\n", qp->tx_mw);
+ seq_printf(s, "tx_index (H) - \t%u\n", qp->tx_index);
+ seq_printf(s, "RRI (T) - \t%u\n", qp->remote_rx_info->entry);
+ seq_printf(s, "tx_max_entry - \t%u\n", qp->tx_max_entry);
+ seq_printf(s, "free tx - \t%u\n", ntb_transport_tx_free_entry(qp));
+ seq_putc(s, '\n');
+
+ seq_printf(s, "Using TX DMA - \t%s\n", qp->tx_dma_chan ? "Yes" : "No");
+ seq_printf(s, "Using RX DMA - \t%s\n", qp->rx_dma_chan ? "Yes" : "No");
+ seq_printf(s, "QP Link - \t%s\n", qp->link_is_up ? "Up" : "Down");
+ seq_putc(s, '\n');
- out_offset = 0;
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "\nNTB QP stats:\n\n");
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "rx_bytes - \t%llu\n", qp->rx_bytes);
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "rx_pkts - \t%llu\n", qp->rx_pkts);
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "rx_memcpy - \t%llu\n", qp->rx_memcpy);
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "rx_async - \t%llu\n", qp->rx_async);
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "rx_ring_empty - %llu\n", qp->rx_ring_empty);
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "rx_err_no_buf - %llu\n", qp->rx_err_no_buf);
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "rx_err_oflow - \t%llu\n", qp->rx_err_oflow);
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "rx_err_ver - \t%llu\n", qp->rx_err_ver);
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "rx_buff - \t0x%p\n", qp->rx_buff);
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "rx_index - \t%u\n", qp->rx_index);
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "rx_max_entry - \t%u\n", qp->rx_max_entry);
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "rx_alloc_entry - \t%u\n\n", qp->rx_alloc_entry);
-
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "tx_bytes - \t%llu\n", qp->tx_bytes);
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "tx_pkts - \t%llu\n", qp->tx_pkts);
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "tx_memcpy - \t%llu\n", qp->tx_memcpy);
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "tx_async - \t%llu\n", qp->tx_async);
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "tx_ring_full - \t%llu\n", qp->tx_ring_full);
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "tx_err_no_buf - %llu\n", qp->tx_err_no_buf);
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "tx_mw - \t0x%p\n", qp->tx_mw);
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "tx_index (H) - \t%u\n", qp->tx_index);
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "RRI (T) - \t%u\n",
- qp->remote_rx_info->entry);
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "tx_max_entry - \t%u\n", qp->tx_max_entry);
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "free tx - \t%u\n",
- ntb_transport_tx_free_entry(qp));
-
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "\n");
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "Using TX DMA - \t%s\n",
- qp->tx_dma_chan ? "Yes" : "No");
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "Using RX DMA - \t%s\n",
- qp->rx_dma_chan ? "Yes" : "No");
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "QP Link - \t%s\n",
- qp->link_is_up ? "Up" : "Down");
- out_offset += scnprintf(buf + out_offset, out_count - out_offset,
- "\n");
-
- if (out_offset > out_count)
- out_offset = out_count;
-
- ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
- kfree(buf);
- return ret;
-}
-
-static const struct file_operations ntb_qp_debugfs_stats = {
- .owner = THIS_MODULE,
- .open = simple_open,
- .read = debugfs_read,
-};
+ return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(ntb_qp_debugfs_stats);
static void ntb_list_add(spinlock_t *lock, struct list_head *entry,
struct list_head *list)
@@ -1236,15 +1182,15 @@ static int ntb_transport_init_queue(struct ntb_transport_ctx *nt,
qp->tx_max_entry = tx_size / qp->tx_max_frame;
if (nt->debugfs_node_dir) {
- char debugfs_name[4];
+ char debugfs_name[8];
- snprintf(debugfs_name, 4, "qp%d", qp_num);
+ snprintf(debugfs_name, sizeof(debugfs_name), "qp%d", qp_num);
qp->debugfs_dir = debugfs_create_dir(debugfs_name,
nt->debugfs_node_dir);
qp->debugfs_stats = debugfs_create_file("stats", S_IRUSR,
qp->debugfs_dir, qp,
- &ntb_qp_debugfs_stats);
+ &ntb_qp_debugfs_stats_fops);
} else {
qp->debugfs_dir = NULL;
qp->debugfs_stats = NULL;
--
2.51.0
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH] NTB: ntb_transport: Use seq_file for QP stats debugfs
2025-12-17 14:18 Koichiro Den
@ 2025-12-18 4:46 ` Koichiro Den
0 siblings, 0 replies; 5+ messages in thread
From: Koichiro Den @ 2025-12-18 4:46 UTC (permalink / raw)
To: ntb; +Cc: jdmason, dave.jiang, allenbh, Frank.Li, linux-kernel
On Wed, Dec 17, 2025 at 11:18:01PM +0900, Koichiro Den wrote:
> The ./qp*/stats debugfs file for each NTB transport QP is currently
> implemented with a hand-crafted kmalloc() buffer and a series of
> scnprintf() calls. This is a pre-seq_file style pattern and makes future
> extensions easy to truncate.
>
> Convert the stats file to use the seq_file helpers via
> DEFINE_SHOW_ATTRIBUTE(), which simplifies the code and lets the seq_file
> core handle buffering and partial reads.
>
> While touching this area, fix a bug in the per-QP debugfs directory
> naming: the buffer used for "qp%d" was only 4 bytes, which truncates
> names like "qp10" to "qp1" and causes multiple queues to share the same
> directory. Enlarge the buffer and use sizeof() to avoid truncation.
>
> Reviewed-by: Frank Li <Frank.Li@nxp.com>
> Signed-off-by: Koichiro Den <den@valinux.co.jp>
Please disregard this submission.
This patch was re-sent because it initially appeared not to have
successfully reached ML. However, both submissions showed up in the end,
resulting in duplicate postings.
The original submission is here:
https://lore.kernel.org/all/20251217081955.3137163-1-den@valinux.co.jp/
Sorry for the noise.
Koichiro
> ---
> Note: This patch is split out from the following series, where it was
> originally included as a preparatory change (refactor + small fix):
> https://lore.kernel.org/all/aS3xe0CNHeIMUu7P@lizhi-Precision-Tower-5810/
>
> drivers/ntb/ntb_transport.c | 136 +++++++++++-------------------------
> 1 file changed, 41 insertions(+), 95 deletions(-)
>
> diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c
> index eb875e3db2e3..d5a544bf8fd6 100644
> --- a/drivers/ntb/ntb_transport.c
> +++ b/drivers/ntb/ntb_transport.c
> @@ -57,6 +57,7 @@
> #include <linux/module.h>
> #include <linux/pci.h>
> #include <linux/slab.h>
> +#include <linux/seq_file.h>
> #include <linux/types.h>
> #include <linux/uaccess.h>
> #include <linux/mutex.h>
> @@ -466,104 +467,49 @@ void ntb_transport_unregister_client(struct ntb_transport_client *drv)
> }
> EXPORT_SYMBOL_GPL(ntb_transport_unregister_client);
>
> -static ssize_t debugfs_read(struct file *filp, char __user *ubuf, size_t count,
> - loff_t *offp)
> +static int ntb_qp_debugfs_stats_show(struct seq_file *s, void *v)
> {
> - struct ntb_transport_qp *qp;
> - char *buf;
> - ssize_t ret, out_offset, out_count;
> -
> - qp = filp->private_data;
> + struct ntb_transport_qp *qp = s->private;
>
> if (!qp || !qp->link_is_up)
> return 0;
>
> - out_count = 1000;
> -
> - buf = kmalloc(out_count, GFP_KERNEL);
> - if (!buf)
> - return -ENOMEM;
> + seq_puts(s, "\nNTB QP stats:\n\n");
> +
> + seq_printf(s, "rx_bytes - \t%llu\n", qp->rx_bytes);
> + seq_printf(s, "rx_pkts - \t%llu\n", qp->rx_pkts);
> + seq_printf(s, "rx_memcpy - \t%llu\n", qp->rx_memcpy);
> + seq_printf(s, "rx_async - \t%llu\n", qp->rx_async);
> + seq_printf(s, "rx_ring_empty - %llu\n", qp->rx_ring_empty);
> + seq_printf(s, "rx_err_no_buf - %llu\n", qp->rx_err_no_buf);
> + seq_printf(s, "rx_err_oflow - \t%llu\n", qp->rx_err_oflow);
> + seq_printf(s, "rx_err_ver - \t%llu\n", qp->rx_err_ver);
> + seq_printf(s, "rx_buff - \t0x%p\n", qp->rx_buff);
> + seq_printf(s, "rx_index - \t%u\n", qp->rx_index);
> + seq_printf(s, "rx_max_entry - \t%u\n", qp->rx_max_entry);
> + seq_printf(s, "rx_alloc_entry - \t%u\n\n", qp->rx_alloc_entry);
> +
> + seq_printf(s, "tx_bytes - \t%llu\n", qp->tx_bytes);
> + seq_printf(s, "tx_pkts - \t%llu\n", qp->tx_pkts);
> + seq_printf(s, "tx_memcpy - \t%llu\n", qp->tx_memcpy);
> + seq_printf(s, "tx_async - \t%llu\n", qp->tx_async);
> + seq_printf(s, "tx_ring_full - \t%llu\n", qp->tx_ring_full);
> + seq_printf(s, "tx_err_no_buf - %llu\n", qp->tx_err_no_buf);
> + seq_printf(s, "tx_mw - \t0x%p\n", qp->tx_mw);
> + seq_printf(s, "tx_index (H) - \t%u\n", qp->tx_index);
> + seq_printf(s, "RRI (T) - \t%u\n", qp->remote_rx_info->entry);
> + seq_printf(s, "tx_max_entry - \t%u\n", qp->tx_max_entry);
> + seq_printf(s, "free tx - \t%u\n", ntb_transport_tx_free_entry(qp));
> + seq_putc(s, '\n');
> +
> + seq_printf(s, "Using TX DMA - \t%s\n", qp->tx_dma_chan ? "Yes" : "No");
> + seq_printf(s, "Using RX DMA - \t%s\n", qp->rx_dma_chan ? "Yes" : "No");
> + seq_printf(s, "QP Link - \t%s\n", qp->link_is_up ? "Up" : "Down");
> + seq_putc(s, '\n');
>
> - out_offset = 0;
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "\nNTB QP stats:\n\n");
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "rx_bytes - \t%llu\n", qp->rx_bytes);
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "rx_pkts - \t%llu\n", qp->rx_pkts);
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "rx_memcpy - \t%llu\n", qp->rx_memcpy);
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "rx_async - \t%llu\n", qp->rx_async);
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "rx_ring_empty - %llu\n", qp->rx_ring_empty);
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "rx_err_no_buf - %llu\n", qp->rx_err_no_buf);
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "rx_err_oflow - \t%llu\n", qp->rx_err_oflow);
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "rx_err_ver - \t%llu\n", qp->rx_err_ver);
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "rx_buff - \t0x%p\n", qp->rx_buff);
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "rx_index - \t%u\n", qp->rx_index);
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "rx_max_entry - \t%u\n", qp->rx_max_entry);
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "rx_alloc_entry - \t%u\n\n", qp->rx_alloc_entry);
> -
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "tx_bytes - \t%llu\n", qp->tx_bytes);
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "tx_pkts - \t%llu\n", qp->tx_pkts);
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "tx_memcpy - \t%llu\n", qp->tx_memcpy);
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "tx_async - \t%llu\n", qp->tx_async);
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "tx_ring_full - \t%llu\n", qp->tx_ring_full);
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "tx_err_no_buf - %llu\n", qp->tx_err_no_buf);
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "tx_mw - \t0x%p\n", qp->tx_mw);
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "tx_index (H) - \t%u\n", qp->tx_index);
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "RRI (T) - \t%u\n",
> - qp->remote_rx_info->entry);
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "tx_max_entry - \t%u\n", qp->tx_max_entry);
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "free tx - \t%u\n",
> - ntb_transport_tx_free_entry(qp));
> -
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "\n");
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "Using TX DMA - \t%s\n",
> - qp->tx_dma_chan ? "Yes" : "No");
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "Using RX DMA - \t%s\n",
> - qp->rx_dma_chan ? "Yes" : "No");
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "QP Link - \t%s\n",
> - qp->link_is_up ? "Up" : "Down");
> - out_offset += scnprintf(buf + out_offset, out_count - out_offset,
> - "\n");
> -
> - if (out_offset > out_count)
> - out_offset = out_count;
> -
> - ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
> - kfree(buf);
> - return ret;
> -}
> -
> -static const struct file_operations ntb_qp_debugfs_stats = {
> - .owner = THIS_MODULE,
> - .open = simple_open,
> - .read = debugfs_read,
> -};
> + return 0;
> +}
> +DEFINE_SHOW_ATTRIBUTE(ntb_qp_debugfs_stats);
>
> static void ntb_list_add(spinlock_t *lock, struct list_head *entry,
> struct list_head *list)
> @@ -1236,15 +1182,15 @@ static int ntb_transport_init_queue(struct ntb_transport_ctx *nt,
> qp->tx_max_entry = tx_size / qp->tx_max_frame;
>
> if (nt->debugfs_node_dir) {
> - char debugfs_name[4];
> + char debugfs_name[8];
>
> - snprintf(debugfs_name, 4, "qp%d", qp_num);
> + snprintf(debugfs_name, sizeof(debugfs_name), "qp%d", qp_num);
> qp->debugfs_dir = debugfs_create_dir(debugfs_name,
> nt->debugfs_node_dir);
>
> qp->debugfs_stats = debugfs_create_file("stats", S_IRUSR,
> qp->debugfs_dir, qp,
> - &ntb_qp_debugfs_stats);
> + &ntb_qp_debugfs_stats_fops);
> } else {
> qp->debugfs_dir = NULL;
> qp->debugfs_stats = NULL;
> --
> 2.51.0
>
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2026-01-07 4:29 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2025-12-17 8:19 [PATCH] NTB: ntb_transport: Use seq_file for QP stats debugfs Koichiro Den
2026-01-06 16:37 ` Dave Jiang
2026-01-07 4:29 ` Koichiro Den
2025-12-17 14:18 Koichiro Den
2025-12-18 4:46 ` Koichiro Den
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