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NTB Selftest Script

PATCH Superseded Logan Gunthorpe 3 participants 22 messages Jun 15, 2016

Subsystems (2)

v3 of 5 Superseded Latest is v5 →

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#0 lore raw

v3 cover NTB Selftest Script

Changes since v2:

1) As per Allan's suggestion, I've added a patch to postpone the peer memory window setup until the user requests it with a 'peer_trans*' file. This pushes the ntb_tool API closer to the kernel API and allows the link status file to return the raw status of the NTB link.

2) Change the link status file to return the value of ntb_link_is_up instead of the local 'memory window ready' value.

3) Change the link_event file to just block on write. As it was in v2, if multiple users attempted to use the link_event file they could corrupt the state another user had set. Reads to this file are no longer permitted.

4) Updates to the ntb_test script to accommodate the above changes.

5) Added some link tests to the ntb_test script. It will bring the link down and check that the other side agrees.

6) Added a minor bug fix (Patch #10) to ntb_perf. During discussions with Allen it was noticed that the link_is_up flag is never cleared if the link goes away.

---

Changes since v1:

1) Add a comment to explain the *15 in the buf size calculation, as per Allen's feedback.

2) Clean up the changes to the pingpong client as there were some sloppy copying mistakes.

3) Rework the 'link' file in ntb_tool as per Allen's suggestions. I've added a 'link_event' file the works essentially how he's asked. Though, I found no need to use a completion as suggested and the flow is maybe slightly simpler than he's suggested. Just write a boolean to the event file then read to wait for the link to be either up or down. There's still some discussion on the best interface and it's not much work to make additional minor functional changes.

4) Update the selftest script to use the new 'link_event' file.

5) Minor change to the way the selftest script lists devices thanks to Allen's observation.

---

I've written a ntb_test.sh script that would probably be useful if it were included in the kernel. This series ends with that script and includes some useful interface improvements and fixes to the existing ntb test modules. Please see each individual commit for more information. They are mostly independent.

The series is based off of v4.6 plus the patches I've submitted that have been accepted into ntb-next. They've been run through checkpatch with --strict this time.

As always, I'm happy to incorporate any feedback.

Thanks,

Logan

---

Logan Gunthorpe (10):
ntb_perf: Schedule based on time not on performance
ntb_perf: Improve thread handling to increase robustness
ntb_perf: Return results by reading the run file
ntb_perf: Wait for link before running test
ntb_tool: BUG: Ensure the buffer size is large enough to return all
spads
ntb_tool: Postpone memory window initialization for the user
ntb_tool: Add link status and files to debugfs
ntb_pingpong: Add a debugfs file to get the ping count
ntb_test: Add a selftest script for the NTB subsystem
ntb_perf: clear link_is_up flag when the link goes down.

 MAINTAINERS                             |   1 +
 drivers/ntb/test/ntb_perf.c             | 198 +++++++++-----
 drivers/ntb/test/ntb_pingpong.c         |  62 ++++-
 drivers/ntb/test/ntb_tool.c             | 455 ++++++++++++++++++++++----------
 tools/testing/selftests/ntb/ntb_test.sh | 417 +++++++++++++++++++++++++++++
 5 files changed, 932 insertions(+), 201 deletions(-)
 create mode 100755 tools/testing/selftests/ntb/ntb_test.sh

--
2.1.4

#1 lore raw

PATCH v3 1/10 ntb_perf: Schedule based on time not on performance

When debugging performance problems, if some issue causes the ntb hardware to be significantly slower than expected, ntb_perf will hang requiring a reboot because it only schedules once every 4GB.

Instead, schedule based on jiffies so it will not hang the CPU if the transfer is slow.

---
 drivers/ntb/test/ntb_perf.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)
drivers/ntb/test/ntb_perf.c +4 -2
index 4368519..5008ccf 100644
@@ -273,6 +273,7 @@ static int perf_move_data(struct pthr_ctx *pctx, char __iomem *dst, char *src,
 	char __iomem *tmp = dst;
 	u64 perf, diff_us;
 	ktime_t kstart, kstop, kdiff;
+	unsigned long last_sleep = jiffies;
 
 	chunks = div64_u64(win_size, buf_size);
 	total_chunks = div64_u64(total, buf_size);
@@ -288,8 +289,9 @@ static int perf_move_data(struct pthr_ctx *pctx, char __iomem *dst, char *src,
 		} else
 			tmp += buf_size;
 
-		/* Probably should schedule every 4GB to prevent soft hang. */
-		if (((copied % SZ_4G) == 0) && !use_dma) {
+		/* Probably should schedule every 5s to prevent soft hang. */
+		if (unlikely((jiffies - last_sleep) > 5 * HZ)) {
+			last_sleep = jiffies;
 			set_current_state(TASK_INTERRUPTIBLE);
 			schedule_timeout(1);
 		}
Signature · 1 line
2.1.4
#2 lore raw

PATCH v3 2/10 ntb_perf: Improve thread handling to increase robustness

In reply to Logan Gunthorpe

This commit accomplishes a few things:

1) Properly prevent multiple sets of threads from running at once using a mutex. Lots of race issues existed with the thread_cleanup.

2) The mutex allows us to ensure that threads are finished before tearing down the device or module.

3) Don't use kthread_stop when the threads can exit by themselves, as this is counter-indicated by the kthread_create documentation. Threads now wait for kthread_stop to occur.

4) Writing to the run file now blocks until the threads are complete. The test can then be safely interrupted by a SIGINT.

Also, while I was at it:

5) debugfs_run_write shouldn't return 0 in the early check cases as this could cause debugfs_run_write to loop undesirably.

---
 drivers/ntb/test/ntb_perf.c | 124 +++++++++++++++++++++++++++-----------------
 1 file changed, 76 insertions(+), 48 deletions(-)
drivers/ntb/test/ntb_perf.c +76 -48
index 5008ccf..db4dc61 100644
@@ -58,6 +58,7 @@
 #include <linux/delay.h>
 #include <linux/sizes.h>
 #include <linux/ntb.h>
+#include <linux/mutex.h>
 
 #define DRIVER_NAME		"ntb_perf"
 #define DRIVER_DESCRIPTION	"PCIe NTB Performance Measurement Tool"
@@ -121,6 +122,7 @@ struct pthr_ctx {
 	int			dma_prep_err;
 	int			src_idx;
 	void			*srcs[MAX_SRCS];
+	wait_queue_head_t       *wq;
 };
 
 struct perf_ctx {
@@ -134,9 +136,11 @@ struct perf_ctx {
 	struct dentry		*debugfs_run;
 	struct dentry		*debugfs_threads;
 	u8			perf_threads;
-	bool			run;
+	/* mutex ensures only one set of threads run at once */
+	struct mutex		run_mutex;
 	struct pthr_ctx		pthr_ctx[MAX_THREADS];
 	atomic_t		tsync;
+	atomic_t                tdone;
 };
 
 enum {
@@ -295,12 +299,18 @@ static int perf_move_data(struct pthr_ctx *pctx, char __iomem *dst, char *src,
 			set_current_state(TASK_INTERRUPTIBLE);
 			schedule_timeout(1);
 		}
+
+		if (unlikely(kthread_should_stop()))
+			break;
 	}
 
 	if (use_dma) {
 		pr_info("%s: All DMA descriptors submitted\n", current->comm);
-		while (atomic_read(&pctx->dma_sync) != 0)
+		while (atomic_read(&pctx->dma_sync) != 0) {
+			if (kthread_should_stop())
+				break;
 			msleep(20);
+		}
 	}
 
 	kstop = ktime_get();
@@ -393,7 +403,10 @@ static int ntb_perf_thread(void *data)
 		pctx->srcs[i] = NULL;
 	}
 
-	return 0;
+	atomic_inc(&perf->tdone);
+	wake_up(pctx->wq);
+	rc = 0;
+	goto done;
 
 err:
 	for (i = 0; i < MAX_SRCS; i++) {
@@ -406,6 +419,16 @@ err:
 		pctx->dma_chan = NULL;
 	}
 
+done:
+	/* Wait until we are told to stop */
+	for (;;) {
+		set_current_state(TASK_INTERRUPTIBLE);
+		if (kthread_should_stop())
+			break;
+		schedule();
+	}
+	__set_current_state(TASK_RUNNING);
+
 	return rc;
 }
 
@@ -553,6 +576,7 @@ static ssize_t debugfs_run_read(struct file *filp, char __user *ubuf,
 	struct perf_ctx *perf = filp->private_data;
 	char *buf;
 	ssize_t ret, out_offset;
+	int running;
 
 	if (!perf)
 		return 0;
@@ -560,7 +584,9 @@ static ssize_t debugfs_run_read(struct file *filp, char __user *ubuf,
 	buf = kmalloc(64, GFP_KERNEL);
 	if (!buf)
 		return -ENOMEM;
-	out_offset = snprintf(buf, 64, "%d\n", perf->run);
+
+	running = mutex_is_locked(&perf->run_mutex);
+	out_offset = snprintf(buf, 64, "%d\n", running);
 	ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
 	kfree(buf);
 
@@ -572,7 +598,6 @@ static void threads_cleanup(struct perf_ctx *perf)
 	struct pthr_ctx *pctx;
 	int i;
 
-	perf->run = false;
 	for (i = 0; i < MAX_THREADS; i++) {
 		pctx = &perf->pthr_ctx[i];
 		if (pctx->thread) {
@@ -587,65 +612,66 @@ static ssize_t debugfs_run_write(struct file *filp, const char __user *ubuf,
 {
 	struct perf_ctx *perf = filp->private_data;
 	int node, i;
+	DECLARE_WAIT_QUEUE_HEAD(wq);
 
 	if (!perf->link_is_up)
-		return 0;
+		return -ENOLINK;
 
 	if (perf->perf_threads == 0)
-		return 0;
+		return -EINVAL;
 
-	if (atomic_read(&perf->tsync) == 0)
-		perf->run = false;
+	if (!mutex_trylock(&perf->run_mutex))
+		return -EBUSY;
 
-	if (perf->run)
-		threads_cleanup(perf);
-	else {
-		perf->run = true;
+	if (perf->perf_threads > MAX_THREADS) {
+		perf->perf_threads = MAX_THREADS;
+		pr_info("Reset total threads to: %u\n", MAX_THREADS);
+	}
 
-		if (perf->perf_threads > MAX_THREADS) {
-			perf->perf_threads = MAX_THREADS;
-			pr_info("Reset total threads to: %u\n", MAX_THREADS);
-		}
+	/* no greater than 1M */
+	if (seg_order > MAX_SEG_ORDER) {
+		seg_order = MAX_SEG_ORDER;
+		pr_info("Fix seg_order to %u\n", seg_order);
+	}
 
-		/* no greater than 1M */
-		if (seg_order > MAX_SEG_ORDER) {
-			seg_order = MAX_SEG_ORDER;
-			pr_info("Fix seg_order to %u\n", seg_order);
-		}
+	if (run_order < seg_order) {
+		run_order = seg_order;
+		pr_info("Fix run_order to %u\n", run_order);
+	}
 
-		if (run_order < seg_order) {
-			run_order = seg_order;
-			pr_info("Fix run_order to %u\n", run_order);
-		}
+	node = dev_to_node(&perf->ntb->pdev->dev);
+	atomic_set(&perf->tdone, 0);
 
-		node = dev_to_node(&perf->ntb->pdev->dev);
-		/* launch kernel thread */
-		for (i = 0; i < perf->perf_threads; i++) {
-			struct pthr_ctx *pctx;
-
-			pctx = &perf->pthr_ctx[i];
-			atomic_set(&pctx->dma_sync, 0);
-			pctx->perf = perf;
-			pctx->thread =
-				kthread_create_on_node(ntb_perf_thread,
-						       (void *)pctx,
-						       node, "ntb_perf %d", i);
-			if (IS_ERR(pctx->thread)) {
-				pctx->thread = NULL;
-				goto err;
-			} else
-				wake_up_process(pctx->thread);
-
-			if (perf->run == false)
-				return -ENXIO;
-		}
+	/* launch kernel thread */
+	for (i = 0; i < perf->perf_threads; i++) {
+		struct pthr_ctx *pctx;
 
+		pctx = &perf->pthr_ctx[i];
+		atomic_set(&pctx->dma_sync, 0);
+		pctx->perf = perf;
+		pctx->wq = &wq;
+		pctx->thread =
+			kthread_create_on_node(ntb_perf_thread,
+					       (void *)pctx,
+					       node, "ntb_perf %d", i);
+		if (IS_ERR(pctx->thread)) {
+			pctx->thread = NULL;
+			goto err;
+		} else {
+			wake_up_process(pctx->thread);
+		}
 	}
 
+	wait_event_interruptible(wq,
+		atomic_read(&perf->tdone) == perf->perf_threads);
+
+	threads_cleanup(perf);
+	mutex_unlock(&perf->run_mutex);
 	return count;
 
 err:
 	threads_cleanup(perf);
+	mutex_unlock(&perf->run_mutex);
 	return -ENXIO;
 }
 
@@ -713,7 +739,7 @@ static int perf_probe(struct ntb_client *client, struct ntb_dev *ntb)
 	perf->ntb = ntb;
 	perf->perf_threads = 1;
 	atomic_set(&perf->tsync, 0);
-	perf->run = false;
+	mutex_init(&perf->run_mutex);
 	spin_lock_init(&perf->db_lock);
 	perf_setup_mw(ntb, perf);
 	INIT_DELAYED_WORK(&perf->link_work, perf_link_work);
@@ -748,6 +774,8 @@ static void perf_remove(struct ntb_client *client, struct ntb_dev *ntb)
 
 	dev_dbg(&perf->ntb->dev, "%s called\n", __func__);
 
+	mutex_lock(&perf->run_mutex);
+
 	cancel_delayed_work_sync(&perf->link_work);
 	cancel_work_sync(&perf->link_cleanup);
 
Signature · 1 line
2.1.4
#3 lore raw

PATCH v3 3/10 ntb_perf: Return results by reading the run file

In reply to Logan Gunthorpe

Instead of having to watch logs, allow the results to be retrieved by reading back the run file. This file will return "running" when the test is running and nothing if no tests have been run yet. It returns 1 line per thread, and will display an error message if the corresponding thread returns an error.

With the above change, the pr_info calls that returned the results are then changed to pr_debug calls.

---
 drivers/ntb/test/ntb_perf.c | 67 +++++++++++++++++++++++++++++++++++++--------
 1 file changed, 55 insertions(+), 12 deletions(-)
drivers/ntb/test/ntb_perf.c +55 -12
index db4dc61..05a8705 100644
@@ -123,6 +123,9 @@ struct pthr_ctx {
 	int			src_idx;
 	void			*srcs[MAX_SRCS];
 	wait_queue_head_t       *wq;
+	int			status;
+	u64			copied;
+	u64			diff_us;
 };
 
 struct perf_ctx {
@@ -305,7 +308,7 @@ static int perf_move_data(struct pthr_ctx *pctx, char __iomem *dst, char *src,
 	}
 
 	if (use_dma) {
-		pr_info("%s: All DMA descriptors submitted\n", current->comm);
+		pr_debug("%s: All DMA descriptors submitted\n", current->comm);
 		while (atomic_read(&pctx->dma_sync) != 0) {
 			if (kthread_should_stop())
 				break;
@@ -317,13 +320,16 @@ static int perf_move_data(struct pthr_ctx *pctx, char __iomem *dst, char *src,
 	kdiff = ktime_sub(kstop, kstart);
 	diff_us = ktime_to_us(kdiff);
 
-	pr_info("%s: copied %llu bytes\n", current->comm, copied);
+	pr_debug("%s: copied %llu bytes\n", current->comm, copied);
 
-	pr_info("%s: lasted %llu usecs\n", current->comm, diff_us);
+	pr_debug("%s: lasted %llu usecs\n", current->comm, diff_us);
 
 	perf = div64_u64(copied, diff_us);
 
-	pr_info("%s: MBytes/s: %llu\n", current->comm, perf);
+	pr_debug("%s: MBytes/s: %llu\n", current->comm, perf);
+
+	pctx->copied = copied;
+	pctx->diff_us = diff_us;
 
 	return 0;
 }
@@ -345,7 +351,7 @@ static int ntb_perf_thread(void *data)
 	int rc, node, i;
 	struct dma_chan *dma_chan = NULL;
 
-	pr_info("kthread %s starting...\n", current->comm);
+	pr_debug("kthread %s starting...\n", current->comm);
 
 	node = dev_to_node(&pdev->dev);
 
@@ -575,19 +581,44 @@ static ssize_t debugfs_run_read(struct file *filp, char __user *ubuf,
 {
 	struct perf_ctx *perf = filp->private_data;
 	char *buf;
-	ssize_t ret, out_offset;
-	int running;
+	ssize_t ret, out_off = 0;
+	struct pthr_ctx *pctx;
+	int i;
+	u64 rate;
 
 	if (!perf)
 		return 0;
 
-	buf = kmalloc(64, GFP_KERNEL);
+	buf = kmalloc(1024, GFP_KERNEL);
 	if (!buf)
 		return -ENOMEM;
 
-	running = mutex_is_locked(&perf->run_mutex);
-	out_offset = snprintf(buf, 64, "%d\n", running);
-	ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
+	if (mutex_is_locked(&perf->run_mutex)) {
+		out_off = snprintf(buf, 64, "running\n");
+		goto read_from_buf;
+	}
+
+	for (i = 0; i < MAX_THREADS; i++) {
+		pctx = &perf->pthr_ctx[i];
+
+		if (pctx->status == -ENODATA)
+			break;
+
+		if (pctx->status) {
+			out_off += snprintf(buf + out_off, 1024 - out_off,
+					    "%d: error %d\n", i,
+					    pctx->status);
+			continue;
+		}
+
+		rate = div64_u64(pctx->copied, pctx->diff_us);
+		out_off += snprintf(buf + out_off, 1024 - out_off,
+			"%d: copied %llu bytes in %llu usecs, %llu MBytes/s\n",
+			i, pctx->copied, pctx->diff_us, rate);
+	}
+
+read_from_buf:
+	ret = simple_read_from_buffer(ubuf, count, offp, buf, out_off);
 	kfree(buf);
 
 	return ret;
@@ -601,12 +632,20 @@ static void threads_cleanup(struct perf_ctx *perf)
 	for (i = 0; i < MAX_THREADS; i++) {
 		pctx = &perf->pthr_ctx[i];
 		if (pctx->thread) {
-			kthread_stop(pctx->thread);
+			pctx->status = kthread_stop(pctx->thread);
 			pctx->thread = NULL;
 		}
 	}
 }
 
+static void perf_clear_thread_status(struct perf_ctx *perf)
+{
+	int i;
+
+	for (i = 0; i < MAX_THREADS; i++)
+		perf->pthr_ctx[i].status = -ENODATA;
+}
+
 static ssize_t debugfs_run_write(struct file *filp, const char __user *ubuf,
 				 size_t count, loff_t *offp)
 {
@@ -623,6 +662,8 @@ static ssize_t debugfs_run_write(struct file *filp, const char __user *ubuf,
 	if (!mutex_trylock(&perf->run_mutex))
 		return -EBUSY;
 
+	perf_clear_thread_status(perf);
+
 	if (perf->perf_threads > MAX_THREADS) {
 		perf->perf_threads = MAX_THREADS;
 		pr_info("Reset total threads to: %u\n", MAX_THREADS);
@@ -757,6 +798,8 @@ static int perf_probe(struct ntb_client *client, struct ntb_dev *ntb)
 	if (rc)
 		goto err_ctx;
 
+	perf_clear_thread_status(perf);
+
 	return 0;
 
 err_ctx:
Signature · 1 line
2.1.4
#4 lore raw

PATCH v3 4/10 ntb_perf: Wait for link before running test

In reply to Logan Gunthorpe

Instead of returning immediately with an error when the link is down, wait for the link to come up (or the user sends a SIGINT).

This is to make scripting ntb_perf easier.

---
 drivers/ntb/test/ntb_perf.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)
drivers/ntb/test/ntb_perf.c +4 -1
index 05a8705..f0784e5 100644
@@ -135,6 +135,7 @@ struct perf_ctx {
 	bool			link_is_up;
 	struct work_struct	link_cleanup;
 	struct delayed_work	link_work;
+	wait_queue_head_t	link_wq;
 	struct dentry		*debugfs_node_dir;
 	struct dentry		*debugfs_run;
 	struct dentry		*debugfs_threads;
@@ -533,6 +534,7 @@ static void perf_link_work(struct work_struct *work)
 		goto out1;
 
 	perf->link_is_up = true;
+	wake_up(&perf->link_wq);
 
 	return;
 
@@ -653,7 +655,7 @@ static ssize_t debugfs_run_write(struct file *filp, const char __user *ubuf,
 	int node, i;
 	DECLARE_WAIT_QUEUE_HEAD(wq);
 
-	if (!perf->link_is_up)
+	if (wait_event_interruptible(perf->link_wq, perf->link_is_up))
 		return -ENOLINK;
 
 	if (perf->perf_threads == 0)
@@ -783,6 +785,7 @@ static int perf_probe(struct ntb_client *client, struct ntb_dev *ntb)
 	mutex_init(&perf->run_mutex);
 	spin_lock_init(&perf->db_lock);
 	perf_setup_mw(ntb, perf);
+	init_waitqueue_head(&perf->link_wq);
 	INIT_DELAYED_WORK(&perf->link_work, perf_link_work);
 	INIT_WORK(&perf->link_cleanup, perf_link_cleanup);
 
Signature · 1 line
2.1.4
#5 lore raw

PATCH v3 5/10 ntb_tool: BUG: Ensure the buffer size is large enough to return all spads

In reply to Logan Gunthorpe

On hardware with 32 scratchpad registers the spad field in ntb tool could chop off the end. The maximum buffer size is increased from 256 to 15 times the number or scratchpads.

---
 drivers/ntb/test/ntb_tool.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)
drivers/ntb/test/ntb_tool.c +8 -2
index 4c01057..cba31fd 100644
@@ -368,7 +368,14 @@ static ssize_t tool_spadfn_read(struct tool_ctx *tc, char __user *ubuf,
 	if (!spad_read_fn)
 		return -EINVAL;
 
-	buf_size = min_t(size_t, size, 0x100);
+	spad_count = ntb_spad_count(tc->ntb);
+
+	/*
+	 * We multiply the number of spads by 15 to get the buffer size
+	 * this is from 3 for the %d, 10 for the largest hex value
+	 * (0x00000000) and 2 for the tab and line feed.
+	 */
+	buf_size = min_t(size_t, size, spad_count * 15);
 
 	buf = kmalloc(buf_size, GFP_KERNEL);
 	if (!buf)
@@ -376,7 +383,6 @@ static ssize_t tool_spadfn_read(struct tool_ctx *tc, char __user *ubuf,
 
 	pos = 0;
 
-	spad_count = ntb_spad_count(tc->ntb);
 	for (i = 0; i < spad_count; ++i) {
 		pos += scnprintf(buf + pos, buf_size - pos, "%d\t%#x\n",
 				 i, spad_read_fn(tc->ntb, i));
Signature · 1 line
2.1.4
#6 lore raw

PATCH v3 6/10 ntb_tool: Postpone memory window initialization for the user

In reply to Logan Gunthorpe

In order to make the interface closer to the raw NTB API, this commit changes memory windows so they are not initialized on link up. Instead, the 'peer_trans*' debugfs files are introduced. When read, they return information provided by ntb_mw_get_range. When written, they create a buffer and initialize the memory window. The value written is taken as the requested size of the buffer (which is then rounded for alignment). Writing a value of zero frees the buffer and tears down the memory window translation. The 'peer_mw*' file is only created once the memory window translation is setup by the user.

Additionally, it was noticed that the read and write functions for the 'peer_mw*' files should have checked for a NULL pointer.

---
 drivers/ntb/test/ntb_tool.c | 356 +++++++++++++++++++++++++++-----------------
 1 file changed, 218 insertions(+), 138 deletions(-)
drivers/ntb/test/ntb_tool.c +218 -138
index cba31fd..031723d 100644
@@ -79,6 +79,13 @@
  * root@self# cat $DBG_DIR/spad
  *
  * Observe that spad 0 and 1 have the values set by the peer.
+ *
+ * # Check the memory window translation info
+ * cat $DBG_DIR/peer_trans0
+ *
+ * # Setup a 16k memory window buffer
+ * echo 16384 > $DBG_DIR/peer_trans0
+ *
  */
 
 #include <linux/init.h>
@@ -108,25 +115,22 @@ MODULE_DESCRIPTION(DRIVER_DESCRIPTION);
 
 #define MAX_MWS 16
 
-static unsigned long mw_size = 16;
-module_param(mw_size, ulong, 0644);
-MODULE_PARM_DESC(mw_size, "size order [n^2] of the memory window for testing");
-
 static struct dentry *tool_dbgfs;
 
 struct tool_mw {
+	int idx;
+	struct tool_ctx *tc;
+	resource_size_t win_size;
 	resource_size_t size;
 	u8 __iomem *local;
 	u8 *peer;
 	dma_addr_t peer_dma;
+	struct dentry *peer_dbg_file;
 };
 
 struct tool_ctx {
 	struct ntb_dev *ntb;
 	struct dentry *dbgfs;
-	struct work_struct link_cleanup;
-	bool link_is_up;
-	struct delayed_work link_work;
 	int mw_count;
 	struct tool_mw mws[MAX_MWS];
 };
@@ -143,111 +147,6 @@ struct tool_ctx {
 		.write = __write,		\
 	}
 
-static int tool_setup_mw(struct tool_ctx *tc, int idx)
-{
-	int rc;
-	struct tool_mw *mw = &tc->mws[idx];
-	phys_addr_t base;
-	resource_size_t size, align, align_size;
-
-	if (mw->local)
-		return 0;
-
-	rc = ntb_mw_get_range(tc->ntb, idx, &base, &size, &align,
-			      &align_size);
-	if (rc)
-		return rc;
-
-	mw->size = min_t(resource_size_t, 1 << mw_size, size);
-	mw->size = round_up(mw->size, align);
-	mw->size = round_up(mw->size, align_size);
-
-	mw->local = ioremap_wc(base, size);
-	if (mw->local == NULL)
-		return -EFAULT;
-
-	mw->peer = dma_alloc_coherent(&tc->ntb->pdev->dev, mw->size,
-				      &mw->peer_dma, GFP_KERNEL);
-
-	if (mw->peer == NULL)
-		return -ENOMEM;
-
-	rc = ntb_mw_set_trans(tc->ntb, idx, mw->peer_dma, mw->size);
-	if (rc)
-		return rc;
-
-	return 0;
-}
-
-static void tool_free_mws(struct tool_ctx *tc)
-{
-	int i;
-
-	for (i = 0; i < tc->mw_count; i++) {
-		if (tc->mws[i].peer) {
-			ntb_mw_clear_trans(tc->ntb, i);
-			dma_free_coherent(&tc->ntb->pdev->dev, tc->mws[i].size,
-					  tc->mws[i].peer,
-					  tc->mws[i].peer_dma);
-
-		}
-
-		tc->mws[i].peer = NULL;
-		tc->mws[i].peer_dma = 0;
-
-		if (tc->mws[i].local)
-			iounmap(tc->mws[i].local);
-
-		tc->mws[i].local = NULL;
-	}
-
-	tc->mw_count = 0;
-}
-
-static int tool_setup_mws(struct tool_ctx *tc)
-{
-	int i;
-	int rc;
-
-	tc->mw_count = min(ntb_mw_count(tc->ntb), MAX_MWS);
-
-	for (i = 0; i < tc->mw_count; i++) {
-		rc = tool_setup_mw(tc, i);
-		if (rc)
-			goto err_out;
-	}
-
-	return 0;
-
-err_out:
-	tool_free_mws(tc);
-	return rc;
-}
-
-static void tool_link_work(struct work_struct *work)
-{
-	int rc;
-	struct tool_ctx *tc = container_of(work, struct tool_ctx,
-					   link_work.work);
-
-	tool_free_mws(tc);
-	rc = tool_setup_mws(tc);
-	if (rc)
-		dev_err(&tc->ntb->dev,
-			"Error setting up memory windows: %d\n", rc);
-
-	tc->link_is_up = true;
-}
-
-static void tool_link_cleanup(struct work_struct *work)
-{
-	struct tool_ctx *tc = container_of(work, struct tool_ctx,
-					   link_cleanup);
-
-	if (!tc->link_is_up)
-		cancel_delayed_work_sync(&tc->link_work);
-}
-
 static void tool_link_event(void *ctx)
 {
 	struct tool_ctx *tc = ctx;
@@ -260,10 +159,6 @@ 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);
 
-	if (up)
-		schedule_delayed_work(&tc->link_work, 2*HZ);
-	else
-		schedule_work(&tc->link_cleanup);
 }
 
 static void tool_db_event(void *ctx, int vec)
@@ -591,10 +486,10 @@ static ssize_t tool_mw_read(struct file *filep, char __user *ubuf,
 		return -EIO;
 	if (pos < 0)
 		return -EINVAL;
-	if (pos >= mw->size || !size)
+	if (pos >= mw->win_size || !size)
 		return 0;
-	if (size > mw->size - pos)
-		size = mw->size - pos;
+	if (size > mw->win_size - pos)
+		size = mw->win_size - pos;
 
 	buf = kmalloc(size, GFP_KERNEL);
 	if (!buf)
@@ -627,10 +522,10 @@ static ssize_t tool_mw_write(struct file *filep, const char __user *ubuf,
 
 	if (pos < 0)
 		return -EINVAL;
-	if (pos >= mw->size || !size)
+	if (pos >= mw->win_size || !size)
 		return 0;
-	if (size > mw->size - pos)
-		size = mw->size - pos;
+	if (size > mw->win_size - pos)
+		size = mw->win_size - pos;
 
 	buf = kmalloc(size, GFP_KERNEL);
 	if (!buf)
@@ -658,20 +553,25 @@ static TOOL_FOPS_RDWR(tool_mw_fops,
 		      tool_mw_read,
 		      tool_mw_write);
 
-
 static ssize_t tool_peer_mw_read(struct file *filep, char __user *ubuf,
-				   size_t size, loff_t *offp)
+				 size_t size, loff_t *offp)
 {
 	struct tool_mw *mw = filep->private_data;
 
+	if (!mw->peer)
+		return -ENXIO;
+
 	return simple_read_from_buffer(ubuf, size, offp, mw->peer, mw->size);
 }
 
 static ssize_t tool_peer_mw_write(struct file *filep, const char __user *ubuf,
-				    size_t size, loff_t *offp)
+				  size_t size, loff_t *offp)
 {
 	struct tool_mw *mw = filep->private_data;
 
+	if (!mw->peer)
+		return -ENXIO;
+
 	return simple_write_to_buffer(mw->peer, mw->size, offp, ubuf, size);
 }
 
@@ -679,9 +579,189 @@ static TOOL_FOPS_RDWR(tool_peer_mw_fops,
 		      tool_peer_mw_read,
 		      tool_peer_mw_write);
 
+static int tool_setup_mw(struct tool_ctx *tc, int idx, size_t req_size)
+{
+	int rc;
+	struct tool_mw *mw = &tc->mws[idx];
+	phys_addr_t base;
+	resource_size_t size, align, align_size;
+	char buf[16];
+
+	if (mw->peer)
+		return 0;
+
+	rc = ntb_mw_get_range(tc->ntb, idx, &base, &size, &align,
+			      &align_size);
+	if (rc)
+		return rc;
+
+	mw->size = min_t(resource_size_t, req_size, size);
+	mw->size = round_up(mw->size, align);
+	mw->size = round_up(mw->size, align_size);
+	mw->peer = dma_alloc_coherent(&tc->ntb->pdev->dev, mw->size,
+				      &mw->peer_dma, GFP_KERNEL);
+
+	if (!mw->peer)
+		return -ENOMEM;
+
+	rc = ntb_mw_set_trans(tc->ntb, idx, mw->peer_dma, mw->size);
+	if (rc)
+		return rc;
+
+	snprintf(buf, sizeof(buf), "peer_mw%d", idx);
+	mw->peer_dbg_file = debugfs_create_file(buf, S_IRUSR | S_IWUSR,
+						mw->tc->dbgfs, mw,
+						&tool_peer_mw_fops);
+
+	return 0;
+}
+
+static void tool_free_mw(struct tool_ctx *tc, int idx)
+{
+	struct tool_mw *mw = &tc->mws[idx];
+
+	if (mw->peer) {
+		ntb_mw_clear_trans(tc->ntb, idx);
+		dma_free_coherent(&tc->ntb->pdev->dev, mw->size,
+				  mw->peer,
+				  mw->peer_dma);
+	}
+
+	mw->peer = NULL;
+	mw->peer_dma = 0;
+
+	debugfs_remove(mw->peer_dbg_file);
+
+	mw->peer_dbg_file = NULL;
+}
+
+static ssize_t tool_peer_mw_trans_read(struct file *filep,
+				       char __user *ubuf,
+				       size_t size, loff_t *offp)
+{
+	struct tool_mw *mw = filep->private_data;
+
+	char *buf;
+	size_t buf_size;
+	ssize_t ret, off = 0;
+
+	phys_addr_t base;
+	resource_size_t mw_size;
+	resource_size_t align;
+	resource_size_t align_size;
+
+	buf_size = min_t(size_t, size, 512);
+
+	buf = kmalloc(buf_size, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	ntb_mw_get_range(mw->tc->ntb, mw->idx,
+			 &base, &mw_size, &align, &align_size);
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "Peer MW %d Information:\n", mw->idx);
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "Physical Address      \t%pa[p]\n",
+			 &base);
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "Window Size           \t%lld\n",
+			 (unsigned long long)mw_size);
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "Alignment             \t%lld\n",
+			 (unsigned long long)align);
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "Size Alignment        \t%lld\n",
+			 (unsigned long long)align_size);
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "Ready                 \t%c\n",
+			 (mw->peer) ? 'Y' : 'N');
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "Allocated Size       \t%zd\n",
+			 (mw->peer) ? (size_t)mw->size : 0);
+
+	ret = simple_read_from_buffer(ubuf, size, offp, buf, off);
+	kfree(buf);
+	return ret;
+}
+
+static ssize_t tool_peer_mw_trans_write(struct file *filep,
+					const char __user *ubuf,
+					size_t size, loff_t *offp)
+{
+	struct tool_mw *mw = filep->private_data;
+
+	char buf[32];
+	size_t buf_size;
+	unsigned long long 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 = kstrtoull(buf, 0, &val);
+	if (rc)
+		return rc;
+
+	tool_free_mw(mw->tc, mw->idx);
+	if (val)
+		rc = tool_setup_mw(mw->tc, mw->idx, val);
+
+	if (rc)
+		return rc;
+
+	return size;
+}
+
+static TOOL_FOPS_RDWR(tool_peer_mw_trans_fops,
+		      tool_peer_mw_trans_read,
+		      tool_peer_mw_trans_write);
+
+static int tool_init_mw(struct tool_ctx *tc, int idx)
+{
+	struct tool_mw *mw = &tc->mws[idx];
+	phys_addr_t base;
+	int rc;
+
+	rc = ntb_mw_get_range(tc->ntb, idx, &base, &mw->win_size,
+			      NULL, NULL);
+	if (rc)
+		return rc;
+
+	mw->tc = tc;
+	mw->idx = idx;
+	mw->local = ioremap_wc(base, mw->win_size);
+	if (!mw->local)
+		return -EFAULT;
+
+	return 0;
+}
+
+static void tool_free_mws(struct tool_ctx *tc)
+{
+	int i;
+
+	for (i = 0; i < tc->mw_count; i++) {
+		tool_free_mw(tc, i);
+
+		if (tc->mws[i].local)
+			iounmap(tc->mws[i].local);
+
+		tc->mws[i].local = NULL;
+	}
+}
+
 static void tool_setup_dbgfs(struct tool_ctx *tc)
 {
-	int mw_count;
 	int i;
 
 	/* This modules is useless without dbgfs... */
@@ -713,18 +793,16 @@ 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);
 
-	mw_count = min(ntb_mw_count(tc->ntb), MAX_MWS);
-	for (i = 0; i < mw_count; i++) {
+	for (i = 0; i < tc->mw_count; i++) {
 		char buf[30];
 
 		snprintf(buf, sizeof(buf), "mw%d", i);
 		debugfs_create_file(buf, S_IRUSR | S_IWUSR, tc->dbgfs,
 				    &tc->mws[i], &tool_mw_fops);
 
-		snprintf(buf, sizeof(buf), "peer_mw%d", i);
+		snprintf(buf, sizeof(buf), "peer_trans%d", i);
 		debugfs_create_file(buf, S_IRUSR | S_IWUSR, tc->dbgfs,
-				    &tc->mws[i], &tool_peer_mw_fops);
-
+				    &tc->mws[i], &tool_peer_mw_trans_fops);
 	}
 }
 
@@ -732,6 +810,7 @@ static int tool_probe(struct ntb_client *self, struct ntb_dev *ntb)
 {
 	struct tool_ctx *tc;
 	int rc;
+	int i;
 
 	if (ntb_db_is_unsafe(ntb))
 		dev_dbg(&ntb->dev, "doorbell is unsafe\n");
@@ -746,8 +825,13 @@ static int tool_probe(struct ntb_client *self, struct ntb_dev *ntb)
 	}
 
 	tc->ntb = ntb;
-	INIT_DELAYED_WORK(&tc->link_work, tool_link_work);
-	INIT_WORK(&tc->link_cleanup, tool_link_cleanup);
+
+	tc->mw_count = min(ntb_mw_count(tc->ntb), MAX_MWS);
+	for (i = 0; i < tc->mw_count; i++) {
+		rc = tool_init_mw(tc, i);
+		if (rc)
+			goto err_ctx;
+	}
 
 	tool_setup_dbgfs(tc);
 
@@ -761,9 +845,8 @@ static int tool_probe(struct ntb_client *self, struct ntb_dev *ntb)
 	return 0;
 
 err_ctx:
+	tool_free_mws(tc);
 	debugfs_remove_recursive(tc->dbgfs);
-	cancel_delayed_work_sync(&tc->link_work);
-	cancel_work_sync(&tc->link_cleanup);
 	kfree(tc);
 err_tc:
 	return rc;
@@ -773,9 +856,6 @@ static void tool_remove(struct ntb_client *self, struct ntb_dev *ntb)
 {
 	struct tool_ctx *tc = ntb->ctx;
 
-	cancel_delayed_work_sync(&tc->link_work);
-	cancel_work_sync(&tc->link_cleanup);
-
 	tool_free_mws(tc);
 
 	ntb_clear_ctx(ntb);
Signature · 1 line
2.1.4
Acked-by on v3 6/10
#7 lore raw

RE: [PATCH v3 06/10] ntb_tool: Postpone memory window initialization for the user

From: Logan Gunthorpe

Quoted 10 lines

In order to make the interface closer to the raw NTB API, this commit changes memory windows so they are not initialized on link up. Instead, the 'peer_trans*' debugfs files are introduced. When read, they return information provided by ntb_mw_get_range. When written, they create a buffer and initialize the memory window. The value written is taken as the requested size of the buffer (which is then rounded for alignment). Writing a value of zero frees the buffer and tears down the memory window translation. The 'peer_mw*' file is only created once the memory window translation is setup by the user.

Quoted 4 lines

Additionally, it was noticed that the read and write functions for the 'peer_mw*' files should have checked for a NULL pointer.

I am happy to see all the link_work complexity go away with this patch.

Quoted 493 lines
---
 drivers/ntb/test/ntb_tool.c | 356 +++++++++++++++++++++++++++-----------------
 1 file changed, 218 insertions(+), 138 deletions(-)
drivers/ntb/test/ntb_tool.c +17 -122
index cba31fd..031723d 100644
@@ -79,6 +79,13 @@
  * root@self# cat $DBG_DIR/spad
  *
  * Observe that spad 0 and 1 have the values set by the peer.
+ *
+ * # Check the memory window translation info
+ * cat $DBG_DIR/peer_trans0
+ *
+ * # Setup a 16k memory window buffer
+ * echo 16384 > $DBG_DIR/peer_trans0
+ *
  */
 
 #include <linux/init.h>
@@ -108,25 +115,22 @@ MODULE_DESCRIPTION(DRIVER_DESCRIPTION);
 
 #define MAX_MWS 16
 
-static unsigned long mw_size = 16;
-module_param(mw_size, ulong, 0644);
-MODULE_PARM_DESC(mw_size, "size order [n^2] of the memory window for testing");
-
 static struct dentry *tool_dbgfs;
 
 struct tool_mw {
+	int idx;
+	struct tool_ctx *tc;
+	resource_size_t win_size;
 	resource_size_t size;
 	u8 __iomem *local;
 	u8 *peer;
 	dma_addr_t peer_dma;
+	struct dentry *peer_dbg_file;
 };
 
 struct tool_ctx {
 	struct ntb_dev *ntb;
 	struct dentry *dbgfs;
-	struct work_struct link_cleanup;
-	bool link_is_up;
-	struct delayed_work link_work;
 	int mw_count;
 	struct tool_mw mws[MAX_MWS];
 };
@@ -143,111 +147,6 @@ struct tool_ctx {
 		.write = __write,		\
 	}
 
-static int tool_setup_mw(struct tool_ctx *tc, int idx)
-{
-	int rc;
-	struct tool_mw *mw = &tc->mws[idx];
-	phys_addr_t base;
-	resource_size_t size, align, align_size;
-
-	if (mw->local)
-		return 0;
-
-	rc = ntb_mw_get_range(tc->ntb, idx, &base, &size, &align,
-			      &align_size);
-	if (rc)
-		return rc;
-
-	mw->size = min_t(resource_size_t, 1 << mw_size, size);
-	mw->size = round_up(mw->size, align);
-	mw->size = round_up(mw->size, align_size);
-
-	mw->local = ioremap_wc(base, size);
-	if (mw->local == NULL)
-		return -EFAULT;
-
-	mw->peer = dma_alloc_coherent(&tc->ntb->pdev->dev, mw->size,
-				      &mw->peer_dma, GFP_KERNEL);
-
-	if (mw->peer == NULL)
-		return -ENOMEM;
-
-	rc = ntb_mw_set_trans(tc->ntb, idx, mw->peer_dma, mw->size);
-	if (rc)
-		return rc;
-
-	return 0;
-}
-
-static void tool_free_mws(struct tool_ctx *tc)
-{
-	int i;
-
-	for (i = 0; i < tc->mw_count; i++) {
-		if (tc->mws[i].peer) {
-			ntb_mw_clear_trans(tc->ntb, i);
-			dma_free_coherent(&tc->ntb->pdev->dev, tc->mws[i].size,
-					  tc->mws[i].peer,
-					  tc->mws[i].peer_dma);
-
-		}
-
-		tc->mws[i].peer = NULL;
-		tc->mws[i].peer_dma = 0;
-
-		if (tc->mws[i].local)
-			iounmap(tc->mws[i].local);
-
-		tc->mws[i].local = NULL;
-	}
-
-	tc->mw_count = 0;
-}
-
-static int tool_setup_mws(struct tool_ctx *tc)
-{
-	int i;
-	int rc;
-
-	tc->mw_count = min(ntb_mw_count(tc->ntb), MAX_MWS);
-
-	for (i = 0; i < tc->mw_count; i++) {
-		rc = tool_setup_mw(tc, i);
-		if (rc)
-			goto err_out;
-	}
-
-	return 0;
-
-err_out:
-	tool_free_mws(tc);
-	return rc;
-}
-
-static void tool_link_work(struct work_struct *work)
-{
-	int rc;
-	struct tool_ctx *tc = container_of(work, struct tool_ctx,
-					   link_work.work);
-
-	tool_free_mws(tc);
-	rc = tool_setup_mws(tc);
-	if (rc)
-		dev_err(&tc->ntb->dev,
-			"Error setting up memory windows: %d\n", rc);
-
-	tc->link_is_up = true;
-}
-
-static void tool_link_cleanup(struct work_struct *work)
-{
-	struct tool_ctx *tc = container_of(work, struct tool_ctx,
-					   link_cleanup);
-
-	if (!tc->link_is_up)
-		cancel_delayed_work_sync(&tc->link_work);
-}
-
 static void tool_link_event(void *ctx)
 {
 	struct tool_ctx *tc = ctx;
@@ -260,10 +159,6 @@ 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);
 
-	if (up)
-		schedule_delayed_work(&tc->link_work, 2*HZ);
-	else
-		schedule_work(&tc->link_cleanup);
 }
 
 static void tool_db_event(void *ctx, int vec)
@@ -591,10 +486,10 @@ static ssize_t tool_mw_read(struct file *filep, char __user *ubuf,
 		return -EIO;
 	if (pos < 0)
 		return -EINVAL;
-	if (pos >= mw->size || !size)
+	if (pos >= mw->win_size || !size)
 		return 0;
-	if (size > mw->size - pos)
-		size = mw->size - pos;
+	if (size > mw->win_size - pos)
+		size = mw->win_size - pos;
 
 	buf = kmalloc(size, GFP_KERNEL);
 	if (!buf)
@@ -627,10 +522,10 @@ static ssize_t tool_mw_write(struct file *filep, const char __user
 *ubuf,
 
 	if (pos < 0)
 		return -EINVAL;
-	if (pos >= mw->size || !size)
+	if (pos >= mw->win_size || !size)
 		return 0;
-	if (size > mw->size - pos)
-		size = mw->size - pos;
+	if (size > mw->win_size - pos)
+		size = mw->win_size - pos;
 
 	buf = kmalloc(size, GFP_KERNEL);
drivers/ntb/test/ntb_tool.c +201 -17
 	if (!buf)
@@ -658,20 +553,25 @@ static TOOL_FOPS_RDWR(tool_mw_fops,
 		      tool_mw_read,
 		      tool_mw_write);
 
-
 static ssize_t tool_peer_mw_read(struct file *filep, char __user *ubuf,
-				   size_t size, loff_t *offp)
+				 size_t size, loff_t *offp)
 {
 	struct tool_mw *mw = filep->private_data;
 
+	if (!mw->peer)
+		return -ENXIO;
+
 	return simple_read_from_buffer(ubuf, size, offp, mw->peer, mw->size);
 }
 
 static ssize_t tool_peer_mw_write(struct file *filep, const char __user *ubuf,
-				    size_t size, loff_t *offp)
+				  size_t size, loff_t *offp)
 {
 	struct tool_mw *mw = filep->private_data;
 
+	if (!mw->peer)
+		return -ENXIO;
+
 	return simple_write_to_buffer(mw->peer, mw->size, offp, ubuf, size);
 }
 
@@ -679,9 +579,189 @@ static TOOL_FOPS_RDWR(tool_peer_mw_fops,
 		      tool_peer_mw_read,
 		      tool_peer_mw_write);
 
+static int tool_setup_mw(struct tool_ctx *tc, int idx, size_t req_size)
+{
+	int rc;
+	struct tool_mw *mw = &tc->mws[idx];
+	phys_addr_t base;
+	resource_size_t size, align, align_size;
+	char buf[16];
+
+	if (mw->peer)
+		return 0;
+
+	rc = ntb_mw_get_range(tc->ntb, idx, &base, &size, &align,
+			      &align_size);
+	if (rc)
+		return rc;
+
+	mw->size = min_t(resource_size_t, req_size, size);
+	mw->size = round_up(mw->size, align);
+	mw->size = round_up(mw->size, align_size);
+	mw->peer = dma_alloc_coherent(&tc->ntb->pdev->dev, mw->size,
+				      &mw->peer_dma, GFP_KERNEL);
+
+	if (!mw->peer)
+		return -ENOMEM;
+
+	rc = ntb_mw_set_trans(tc->ntb, idx, mw->peer_dma, mw->size);
+	if (rc)
+		return rc;
+
+	snprintf(buf, sizeof(buf), "peer_mw%d", idx);
+	mw->peer_dbg_file = debugfs_create_file(buf, S_IRUSR | S_IWUSR,
+						mw->tc->dbgfs, mw,
+						&tool_peer_mw_fops);
+
+	return 0;
+}
+
+static void tool_free_mw(struct tool_ctx *tc, int idx)
+{
+	struct tool_mw *mw = &tc->mws[idx];
+
+	if (mw->peer) {
+		ntb_mw_clear_trans(tc->ntb, idx);
+		dma_free_coherent(&tc->ntb->pdev->dev, mw->size,
+				  mw->peer,
+				  mw->peer_dma);
+	}
+
+	mw->peer = NULL;
+	mw->peer_dma = 0;
+
+	debugfs_remove(mw->peer_dbg_file);
+
+	mw->peer_dbg_file = NULL;
+}
+
+static ssize_t tool_peer_mw_trans_read(struct file *filep,
+				       char __user *ubuf,
+				       size_t size, loff_t *offp)
+{
+	struct tool_mw *mw = filep->private_data;
+
+	char *buf;
+	size_t buf_size;
+	ssize_t ret, off = 0;
+
+	phys_addr_t base;
+	resource_size_t mw_size;
+	resource_size_t align;
+	resource_size_t align_size;
+
+	buf_size = min_t(size_t, size, 512);
+
+	buf = kmalloc(buf_size, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	ntb_mw_get_range(mw->tc->ntb, mw->idx,
+			 &base, &mw_size, &align, &align_size);
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "Peer MW %d Information:\n", mw->idx);
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "Physical Address      \t%pa[p]\n",
+			 &base);
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "Window Size           \t%lld\n",
+			 (unsigned long long)mw_size);
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "Alignment             \t%lld\n",
+			 (unsigned long long)align);
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "Size Alignment        \t%lld\n",
+			 (unsigned long long)align_size);
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "Ready                 \t%c\n",
+			 (mw->peer) ? 'Y' : 'N');
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "Allocated Size       \t%zd\n",
+			 (mw->peer) ? (size_t)mw->size : 0);
+
+	ret = simple_read_from_buffer(ubuf, size, offp, buf, off);
+	kfree(buf);
+	return ret;
+}
+
+static ssize_t tool_peer_mw_trans_write(struct file *filep,
+					const char __user *ubuf,
+					size_t size, loff_t *offp)
+{
+	struct tool_mw *mw = filep->private_data;
+
+	char buf[32];
+	size_t buf_size;
+	unsigned long long 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 = kstrtoull(buf, 0, &val);
+	if (rc)
+		return rc;
+
+	tool_free_mw(mw->tc, mw->idx);
+	if (val)
+		rc = tool_setup_mw(mw->tc, mw->idx, val);
+
+	if (rc)
+		return rc;
+
+	return size;
+}
+
+static TOOL_FOPS_RDWR(tool_peer_mw_trans_fops,
+		      tool_peer_mw_trans_read,
+		      tool_peer_mw_trans_write);
+
+static int tool_init_mw(struct tool_ctx *tc, int idx)
+{
+	struct tool_mw *mw = &tc->mws[idx];
+	phys_addr_t base;
+	int rc;
+
+	rc = ntb_mw_get_range(tc->ntb, idx, &base, &mw->win_size,
+			      NULL, NULL);
+	if (rc)
+		return rc;
+
+	mw->tc = tc;
+	mw->idx = idx;
+	mw->local = ioremap_wc(base, mw->win_size);
+	if (!mw->local)
+		return -EFAULT;
+
+	return 0;
+}
+
+static void tool_free_mws(struct tool_ctx *tc)
+{
+	int i;
+
+	for (i = 0; i < tc->mw_count; i++) {
+		tool_free_mw(tc, i);
+
+		if (tc->mws[i].local)
+			iounmap(tc->mws[i].local);
+
+		tc->mws[i].local = NULL;
+	}
+}
+
 static void tool_setup_dbgfs(struct tool_ctx *tc)
 {
-	int mw_count;
 	int i;
 
 	/* This modules is useless without dbgfs... */
@@ -713,18 +793,16 @@ 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);
 
-	mw_count = min(ntb_mw_count(tc->ntb), MAX_MWS);
-	for (i = 0; i < mw_count; i++) {
+	for (i = 0; i < tc->mw_count; i++) {
 		char buf[30];
 
 		snprintf(buf, sizeof(buf), "mw%d", i);
 		debugfs_create_file(buf, S_IRUSR | S_IWUSR, tc->dbgfs,
 				    &tc->mws[i], &tool_mw_fops);
 
-		snprintf(buf, sizeof(buf), "peer_mw%d", i);
+		snprintf(buf, sizeof(buf), "peer_trans%d", i);
 		debugfs_create_file(buf, S_IRUSR | S_IWUSR, tc->dbgfs,
-				    &tc->mws[i], &tool_peer_mw_fops);
-
+				    &tc->mws[i], &tool_peer_mw_trans_fops);
 	}
 }
 
@@ -732,6 +810,7 @@ static int tool_probe(struct ntb_client *self, struct ntb_dev *ntb)
 {
 	struct tool_ctx *tc;
 	int rc;
+	int i;
 
 	if (ntb_db_is_unsafe(ntb))
 		dev_dbg(&ntb->dev, "doorbell is unsafe\n");
@@ -746,8 +825,13 @@ static int tool_probe(struct ntb_client *self, struct ntb_dev *ntb)
 	}
 
 	tc->ntb = ntb;
-	INIT_DELAYED_WORK(&tc->link_work, tool_link_work);
-	INIT_WORK(&tc->link_cleanup, tool_link_cleanup);
+
+	tc->mw_count = min(ntb_mw_count(tc->ntb), MAX_MWS);
+	for (i = 0; i < tc->mw_count; i++) {
+		rc = tool_init_mw(tc, i);
+		if (rc)
+			goto err_ctx;
+	}
 
 	tool_setup_dbgfs(tc);
 
@@ -761,9 +845,8 @@ static int tool_probe(struct ntb_client *self, struct ntb_dev *ntb)
 	return 0;
 
 err_ctx:
+	tool_free_mws(tc);
 	debugfs_remove_recursive(tc->dbgfs);
-	cancel_delayed_work_sync(&tc->link_work);
-	cancel_work_sync(&tc->link_cleanup);
 	kfree(tc);
 err_tc:
 	return rc;
@@ -773,9 +856,6 @@ static void tool_remove(struct ntb_client *self, struct ntb_dev *ntb)
 {
 	struct tool_ctx *tc = ntb->ctx;
 
-	cancel_delayed_work_sync(&tc->link_work);
-	cancel_work_sync(&tc->link_cleanup);
-
 	tool_free_mws(tc);
 
 	ntb_clear_ctx(ntb);
--

2.1.4

#8 lore raw

PATCH v3 7/10 ntb_tool: Add link status and files to debugfs

In reply to 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.

---
 drivers/ntb/test/ntb_tool.c | 89 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 89 insertions(+)
drivers/ntb/test/ntb_tool.c +89 -0
index 031723d..caef74c 100644
@@ -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 +481,80 @@ 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)
+		ntb_link_enable(tc->ntb, NTB_SPEED_AUTO, NTB_WIDTH_AUTO);
+	else
+		ntb_link_disable(tc->ntb);
+
+	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 +875,12 @@ 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 +913,7 @@ 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++) {
Signature · 1 line
2.1.4
Acked-by on v3 7/10
#9 lore raw

RE: [PATCH v3 07/10] ntb_tool: Add link status and files to debugfs

From: Logan Gunthorpe

Quoted 8 lines

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.

Quoted 6 lines

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.

Quoted 141 lines
---
 drivers/ntb/test/ntb_tool.c | 89 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 89 insertions(+)
drivers/ntb/test/ntb_tool.c +89 -1
index 031723d..caef74c 100644
@@ -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 +481,80 @@ 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)
+		ntb_link_enable(tc->ntb, NTB_SPEED_AUTO, NTB_WIDTH_AUTO);
+	else
+		ntb_link_disable(tc->ntb);
+
+	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 +875,12 @@ 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 +913,7 @@ 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

#10 lore raw

PATCH v3 8/10 ntb_pingpong: Add a debugfs file to get the ping count

In reply to Logan Gunthorpe

This commit adds a debugfs 'count' file to ntb_pingpong. This is so testing with ntb_pingpong can be automated beyond just checking the logs for pong messages.

The count file returns a number which increments every pong. The counter can be cleared by writing a zero.

---
 drivers/ntb/test/ntb_pingpong.c | 62 ++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 61 insertions(+), 1 deletion(-)
drivers/ntb/test/ntb_pingpong.c +61 -1
index fe16005..7d31179 100644
@@ -61,6 +61,7 @@
 #include <linux/pci.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>
+#include <linux/debugfs.h>
 
 #include <linux/ntb.h>
 
@@ -96,8 +97,13 @@ struct pp_ctx {
 	spinlock_t			db_lock;
 	struct timer_list		db_timer;
 	unsigned long			db_delay;
+	struct dentry			*debugfs_node_dir;
+	struct dentry			*debugfs_count;
+	atomic_t			count;
 };
 
+static struct dentry *pp_debugfs_dir;
+
 static void pp_ping(unsigned long ctx)
 {
 	struct pp_ctx *pp = (void *)ctx;
@@ -171,10 +177,32 @@ static void pp_db_event(void *ctx, int vec)
 		dev_dbg(&pp->ntb->dev,
 			"Pong vec %d bits %#llx\n",
 			vec, db_bits);
+		atomic_inc(&pp->count);
 	}
 	spin_unlock_irqrestore(&pp->db_lock, irqflags);
 }
 
+static int pp_debugfs_setup(struct pp_ctx *pp)
+{
+	struct pci_dev *pdev = pp->ntb->pdev;
+
+	if (!pp_debugfs_dir)
+		return -ENODEV;
+
+	pp->debugfs_node_dir = debugfs_create_dir(pci_name(pdev),
+						  pp_debugfs_dir);
+	if (!pp->debugfs_node_dir)
+		return -ENODEV;
+
+	pp->debugfs_count = debugfs_create_atomic_t("count", S_IRUSR | S_IWUSR,
+						    pp->debugfs_node_dir,
+						    &pp->count);
+	if (!pp->debugfs_count)
+		return -ENODEV;
+
+	return 0;
+}
+
 static const struct ntb_ctx_ops pp_ops = {
 	.link_event = pp_link_event,
 	.db_event = pp_db_event,
@@ -210,6 +238,7 @@ static int pp_probe(struct ntb_client *client,
 
 	pp->ntb = ntb;
 	pp->db_bits = 0;
+	atomic_set(&pp->count, 0);
 	spin_lock_init(&pp->db_lock);
 	setup_timer(&pp->db_timer, pp_ping, (unsigned long)pp);
 	pp->db_delay = msecs_to_jiffies(delay_ms);
@@ -218,6 +247,10 @@ static int pp_probe(struct ntb_client *client,
 	if (rc)
 		goto err_ctx;
 
+	rc = pp_debugfs_setup(pp);
+	if (rc)
+		goto err_ctx;
+
 	ntb_link_enable(ntb, NTB_SPEED_AUTO, NTB_WIDTH_AUTO);
 	ntb_link_event(ntb);
 
@@ -234,6 +267,8 @@ static void pp_remove(struct ntb_client *client,
 {
 	struct pp_ctx *pp = ntb->ctx;
 
+	debugfs_remove_recursive(pp->debugfs_node_dir);
+
 	ntb_clear_ctx(ntb);
 	del_timer_sync(&pp->db_timer);
 	ntb_link_disable(ntb);
@@ -247,4 +282,29 @@ static struct ntb_client pp_client = {
 		.remove = pp_remove,
 	},
 };
-module_ntb_client(pp_client);
+
+static int __init pp_init(void)
+{
+	int rc;
+
+	if (debugfs_initialized())
+		pp_debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, NULL);
+
+	rc = ntb_register_client(&pp_client);
+	if (rc)
+		goto err_client;
+
+	return 0;
+
+err_client:
+	debugfs_remove_recursive(pp_debugfs_dir);
+	return rc;
+}
+module_init(pp_init);
+
+static void __exit pp_exit(void)
+{
+	ntb_unregister_client(&pp_client);
+	debugfs_remove_recursive(pp_debugfs_dir);
+}
+module_exit(pp_exit);
Signature · 1 line
2.1.4
Acked-by on v3 8/10
#11 lore raw

RE: [PATCH v3 08/10] ntb_pingpong: Add a debugfs file to get the ping count

From: Logan Gunthorpe

Quoted 8 lines

This commit adds a debugfs 'count' file to ntb_pingpong. This is so testing with ntb_pingpong can be automated beyond just checking the logs for pong messages.

The count file returns a number which increments every pong. The counter can be cleared by writing a zero.

Quoted 124 lines
---
 drivers/ntb/test/ntb_pingpong.c | 62 ++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 61 insertions(+), 1 deletion(-)
drivers/ntb/test/ntb_pingpong.c +61 -2
index fe16005..7d31179 100644
@@ -61,6 +61,7 @@
 #include <linux/pci.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>
+#include <linux/debugfs.h>
 
 #include <linux/ntb.h>
 
@@ -96,8 +97,13 @@ struct pp_ctx {
 	spinlock_t			db_lock;
 	struct timer_list		db_timer;
 	unsigned long			db_delay;
+	struct dentry			*debugfs_node_dir;
+	struct dentry			*debugfs_count;
+	atomic_t			count;
 };
 
+static struct dentry *pp_debugfs_dir;
+
 static void pp_ping(unsigned long ctx)
 {
 	struct pp_ctx *pp = (void *)ctx;
@@ -171,10 +177,32 @@ static void pp_db_event(void *ctx, int vec)
 		dev_dbg(&pp->ntb->dev,
 			"Pong vec %d bits %#llx\n",
 			vec, db_bits);
+		atomic_inc(&pp->count);
 	}
 	spin_unlock_irqrestore(&pp->db_lock, irqflags);
 }
 
+static int pp_debugfs_setup(struct pp_ctx *pp)
+{
+	struct pci_dev *pdev = pp->ntb->pdev;
+
+	if (!pp_debugfs_dir)
+		return -ENODEV;
+
+	pp->debugfs_node_dir = debugfs_create_dir(pci_name(pdev),
+						  pp_debugfs_dir);
+	if (!pp->debugfs_node_dir)
+		return -ENODEV;
+
+	pp->debugfs_count = debugfs_create_atomic_t("count", S_IRUSR | S_IWUSR,
+						    pp->debugfs_node_dir,
+						    &pp->count);
+	if (!pp->debugfs_count)
+		return -ENODEV;
+
+	return 0;
+}
+
 static const struct ntb_ctx_ops pp_ops = {
 	.link_event = pp_link_event,
 	.db_event = pp_db_event,
@@ -210,6 +238,7 @@ static int pp_probe(struct ntb_client *client,
 
 	pp->ntb = ntb;
 	pp->db_bits = 0;
+	atomic_set(&pp->count, 0);
 	spin_lock_init(&pp->db_lock);
 	setup_timer(&pp->db_timer, pp_ping, (unsigned long)pp);
 	pp->db_delay = msecs_to_jiffies(delay_ms);
@@ -218,6 +247,10 @@ static int pp_probe(struct ntb_client *client,
 	if (rc)
 		goto err_ctx;
 
+	rc = pp_debugfs_setup(pp);
+	if (rc)
+		goto err_ctx;
+
 	ntb_link_enable(ntb, NTB_SPEED_AUTO, NTB_WIDTH_AUTO);
 	ntb_link_event(ntb);
 
@@ -234,6 +267,8 @@ static void pp_remove(struct ntb_client *client,
 {
 	struct pp_ctx *pp = ntb->ctx;
 
+	debugfs_remove_recursive(pp->debugfs_node_dir);
+
 	ntb_clear_ctx(ntb);
 	del_timer_sync(&pp->db_timer);
 	ntb_link_disable(ntb);
@@ -247,4 +282,29 @@ static struct ntb_client pp_client = {
 		.remove = pp_remove,
 	},
 };
-module_ntb_client(pp_client);
+
+static int __init pp_init(void)
+{
+	int rc;
+
+	if (debugfs_initialized())
+		pp_debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, NULL);
+
+	rc = ntb_register_client(&pp_client);
+	if (rc)
+		goto err_client;
+
+	return 0;
+
+err_client:
+	debugfs_remove_recursive(pp_debugfs_dir);
+	return rc;
+}
+module_init(pp_init);
+
+static void __exit pp_exit(void)
+{
+	ntb_unregister_client(&pp_client);
+	debugfs_remove_recursive(pp_debugfs_dir);
+}
+module_exit(pp_exit);
--

2.1.4

#12 lore raw

PATCH v3 9/10 ntb_test: Add a selftest script for the NTB subsystem

In reply to Logan Gunthorpe

This script automates testing doorbells, scratchpads and memory windows for an NTB device. It can be run locally, with the NTB looped back to the same host or use SSH to remotely control the second host.

In the single host case, the script just needs to be passed two
arguments: a PCI ID for each side of the link. In the two host case the -r option must be used to specify the remote hostname (which must be SSH accessible and should probably have ssh-keys exchanged).

A sample run looks like this:

$ sudo ./ntb_test.sh 0000:03:00.1 0000:83:00.1 -p 29
Starting ntb_tool tests...
Running link tests on: 0000:03:00.1 / 0000:83:00.1
  Passed
Running link tests on: 0000:83:00.1 / 0000:03:00.1
  Passed
Running db tests on: 0000:03:00.1 / 0000:83:00.1
  Passed
Running db tests on: 0000:83:00.1 / 0000:03:00.1
  Passed
Running spad tests on: 0000:03:00.1 / 0000:83:00.1
  Passed
Running spad tests on: 0000:83:00.1 / 0000:03:00.1
  Passed
Running mw0 tests on: 0000:03:00.1 / 0000:83:00.1
  Passed
Running mw0 tests on: 0000:83:00.1 / 0000:03:00.1
  Passed
Running mw1 tests on: 0000:03:00.1 / 0000:83:00.1
  Passed
Running mw1 tests on: 0000:83:00.1 / 0000:03:00.1
  Passed

Starting ntb_pingpong tests...
Running ping pong tests on: 0000:03:00.1 / 0000:83:00.1
Passed

Starting ntb_perf tests...
Running local perf test without DMA
0: copied 536870912 bytes in 164453 usecs, 3264 MBytes/s Passed
Running remote perf test without DMA
0: copied 536870912 bytes in 164453 usecs, 3264 MBytes/s Passed

---
 MAINTAINERS                             |   1 +
 tools/testing/selftests/ntb/ntb_test.sh | 417 ++++++++++++++++++++++++++++++++
 2 files changed, 418 insertions(+)
 create mode 100755 tools/testing/selftests/ntb/ntb_test.sh
MAINTAINERS +1 -0
index 9c567a4..f178e7e 100644
@@ -7846,6 +7846,7 @@ F:	drivers/ntb/
 F:	drivers/net/ntb_netdev.c
 F:	include/linux/ntb.h
 F:	include/linux/ntb_transport.h
+F:	tools/testing/selftests/ntb/
 
 NTB INTEL DRIVER
 M:	Jon Mason <[email protected]>
tools/testing/selftests/ntb/ntb_test.sh new file +417 -0

417 lines not on this page · raw message

Signature · 1 line
2.1.4
Acked-by on v3 9/10
#13 lore raw

RE: [PATCH v3 09/10] ntb_test: Add a selftest script for the NTB subsystem

From: Logan Gunthorpe

Quoted 46 lines

This script automates testing doorbells, scratchpads and memory windows for an NTB device. It can be run locally, with the NTB looped back to the same host or use SSH to remotely control the second host.

In the single host case, the script just needs to be passed two
arguments: a PCI ID for each side of the link. In the two host case the -r option must be used to specify the remote hostname (which must be SSH accessible and should probably have ssh-keys exchanged).

A sample run looks like this:

$ sudo ./ntb_test.sh 0000:03:00.1 0000:83:00.1 -p 29
Starting ntb_tool tests...
Running link tests on: 0000:03:00.1 / 0000:83:00.1
  Passed
Running link tests on: 0000:83:00.1 / 0000:03:00.1
  Passed
Running db tests on: 0000:03:00.1 / 0000:83:00.1
  Passed
Running db tests on: 0000:83:00.1 / 0000:03:00.1
  Passed
Running spad tests on: 0000:03:00.1 / 0000:83:00.1
  Passed
Running spad tests on: 0000:83:00.1 / 0000:03:00.1
  Passed
Running mw0 tests on: 0000:03:00.1 / 0000:83:00.1
  Passed
Running mw0 tests on: 0000:83:00.1 / 0000:03:00.1
  Passed
Running mw1 tests on: 0000:03:00.1 / 0000:83:00.1
  Passed
Running mw1 tests on: 0000:83:00.1 / 0000:03:00.1
  Passed

Starting ntb_pingpong tests...
Running ping pong tests on: 0000:03:00.1 / 0000:83:00.1
Passed

Starting ntb_perf tests...
Running local perf test without DMA
0: copied 536870912 bytes in 164453 usecs, 3264 MBytes/s Passed
Running remote perf test without DMA
0: copied 536870912 bytes in 164453 usecs, 3264 MBytes/s Passed

Quoted 2 lines

note one comment below, link_test

Quoted 147 lines
---
 MAINTAINERS                             |   1 +
 tools/testing/selftests/ntb/ntb_test.sh | 417 ++++++++++++++++++++++++++++++++
 2 files changed, 418 insertions(+)
 create mode 100755 tools/testing/selftests/ntb/ntb_test.sh
MAINTAINERS +1 -0
index 9c567a4..f178e7e 100644
@@ -7846,6 +7846,7 @@ F:	drivers/ntb/
 F:	drivers/net/ntb_netdev.c
 F:	include/linux/ntb.h
 F:	include/linux/ntb_transport.h
+F:	tools/testing/selftests/ntb/
 
 NTB INTEL DRIVER
 M:	Jon Mason <[email protected]>
tools/testing/selftests/ntb/ntb_test.sh new file +122 -0
new file mode 100755
index 0000000..2b7bf81
@@ -0,0 +1,417 @@
+#!/bin/bash
+# Copyright (c) 2016 Microsemi. All Rights Reserved.
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License as
+# published by the Free Software Foundation; either version 2 of
+# the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it would be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# Author: Logan Gunthorpe <[email protected]>
+
+REMOTE_HOST=
+LIST_DEVS=FALSE
+
+DEBUGFS=${DEBUGFS-/sys/kernel/debug}
+
+PERF_RUN_ORDER=32
+MAX_MW_SIZE=0
+RUN_DMA_TESTS=
+DONT_CLEANUP=
+MW_SIZE=65536
+
+function show_help()
+{
+	echo "Usage: $0 [OPTIONS] LOCAL_DEV REMOTE_DEV"
+	echo "Run tests on a pair of NTB endpoints."
+	echo
+	echo "If the NTB device loops back to the same host then,"
+	echo "just specifying the two PCI ids on the command line is"
+	echo "sufficient. Otherwise, if the NTB link spans two hosts"
+	echo "use the -r option to specify the hostname for the remote"
+	echo "device. SSH will then be used to test the remote side."
+	echo "An SSH key between the root users of the host would then"
+	echo "be highly recommended."
+	echo
+	echo "Options:"
+	echo "  -C              don't cleanup ntb modules on exit"
+	echo "  -d              run dma tests"
+	echo "  -h              show this help message"
+	echo "  -l              list available local and remote PCI ids"
+	echo "  -r REMOTE_HOST  specify the remote's hostname to connect"
+        echo "                  to for the test (using ssh)"
+	echo "  -p NUM          ntb_perf run order (default: $PERF_RUN_ORDER)"
+	echo "  -w max_mw_size  maxmium memory window size"
+	echo
+}
+
+function parse_args()
+{
+	OPTIND=0
+	while getopts "Cdhlm:r:p:w:" opt; do
+		case "$opt" in
+		C)  DONT_CLEANUP=1 ;;
+		d)  RUN_DMA_TESTS=1 ;;
+		h)  show_help; exit 0 ;;
+		l)  LIST_DEVS=TRUE ;;
+		m)  MW_SIZE=${OPTARG} ;;
+		r)  REMOTE_HOST=${OPTARG} ;;
+		p)  PERF_RUN_ORDER=${OPTARG} ;;
+		w)  MAX_MW_SIZE=${OPTARG} ;;
+		\?)
+		    echo "Invalid option: -$OPTARG" >&2
+		    exit 1
+		    ;;
+		esac
+	done
+}
+
+parse_args "$@"
+shift $((OPTIND-1))
+LOCAL_DEV=$1
+shift
+parse_args "$@"
+shift $((OPTIND-1))
+REMOTE_DEV=$1
+shift
+parse_args "$@"
+
+set -e
+
+function _modprobe()
+{
+        modprobe "$@"
+}
+
+function split_remote()
+{
+	VPATH=$1
+	REMOTE=
+
+	if [[ "$VPATH" == *":/"* ]]; then
+		REMOTE=${VPATH%%:*}
+		VPATH=${VPATH#*:}
+	fi
+}
+
+function read_file()
+{
+	split_remote $1
+	if [[ "$REMOTE" != "" ]]; then
+		ssh "$REMOTE" cat "$VPATH"
+	else
+		cat "$VPATH"
+	fi
+}
+
+function write_file()
+{
+	split_remote $2
+	VALUE=$1
+
+	if [[ "$REMOTE" != "" ]]; then
+		ssh "$REMOTE" "echo \"$VALUE\" > \"$VPATH\""
+	else
+		echo "$VALUE" > "$VPATH"
+	fi
+}
+

tools/testing/selftests/ntb/ntb_test.sh line 132

Quoted 10 lines
tools/testing/selftests/ntb/ntb_test.sh new file +10 -0
+function link_test()
+{
+	LOC=$1
+	REM=$2
+	EXP=0
+
+	echo "Running link tests on: $(basename $LOC) / $(basename $REM)"
+
+	write_file "N" "$LOC/link"
+	write_file "N" "$LOC/link_event"

If it fails to bring down the link, won't it just block waiting on link_event and never make it to the next step of the test?

Quoted 287 lines
tools/testing/selftests/ntb/ntb_test.sh new file +285 -1
+	if [[ $(read_file "$REM/link") != "N" ]]; then
+		echo "Expected remote link to be down in $REM/link" >&2
+		exit -1
+	fi
+
+	write_file "Y" "$LOC/link"
+	write_file "Y" "$LOC/link_event"
+
+	echo "  Passed"
+}
+
+function doorbell_test()
+{
+	LOC=$1
+	REM=$2
+	EXP=0
+
+	echo "Running db tests on: $(basename $LOC) / $(basename $REM)"
+
+	write_file "c 0xFFFFFFFF" "$REM/db"
+
+	for ((i=1; i <= 8; i++)); do
+		let DB=$(read_file "$REM/db") || true
+		if [[ "$DB" != "$EXP" ]]; then
+			echo "Doorbell doesn't match expected value $EXP " \
+			     "in $REM/db" >&2
+			exit -1
+		fi
+
+		let "MASK=1 << ($i-1)" || true
+		let "EXP=$EXP | $MASK" || true
+		write_file "s $MASK" "$LOC/peer_db"
+	done
+
+	echo "  Passed"
+}
+
+function read_spad()
+{
+       VPATH=$1
+       IDX=$2
+
+       ROW=($(read_file "$VPATH" | grep -e "^$IDX"))
+       let VAL=${ROW[1]} || true
+       echo $VAL
+}
+
+function scratchpad_test()
+{
+	LOC=$1
+	REM=$2
+	CNT=$(read_file "$LOC/spad" | wc -l)
+
+	echo "Running spad tests on: $(basename $LOC) / $(basename $REM)"
+
+	for ((i = 0; i < $CNT; i++)); do
+		VAL=$RANDOM
+		write_file "$i $VAL" "$LOC/peer_spad"
+		RVAL=$(read_spad "$REM/spad" $i)
+
+		if [[ "$VAL" != "$RVAL" ]]; then
+			echo "Scratchpad doesn't match expected value $VAL " \
+			     "in $REM/spad, got $RVAL" >&2
+			exit -1
+		fi
+
+	done
+
+	echo "  Passed"
+}
+
+function write_mw()
+{
+	split_remote $2
+
+	if [[ "$REMOTE" != "" ]]; then
+		ssh "$REMOTE" \
+			dd if=/dev/urandom "of=$VPATH" 2> /dev/null || true
+	else
+		dd if=/dev/urandom "of=$VPATH" 2> /dev/null || true
+	fi
+}
+
+function mw_test()
+{
+	IDX=$1
+	LOC=$2
+	REM=$3
+
+	echo "Running $IDX tests on: $(basename $LOC) / $(basename $REM)"
+
+	write_mw "$LOC/$IDX"
+
+	split_remote "$LOC/$IDX"
+	if [[ "$REMOTE" == "" ]]; then
+		A=$VPATH
+	else
+		A=/tmp/ntb_test.$$.A
+		ssh "$REMOTE" cat "$VPATH" > "$A"
+	fi
+
+	split_remote "$REM/peer_$IDX"
+	if [[ "$REMOTE" == "" ]]; then
+		B=$VPATH
+	else
+		B=/tmp/ntb_test.$$.B
+		ssh "$REMOTE" cat "$VPATH" > "$B"
+	fi
+
+	cmp -n $MW_SIZE "$A" "$B"
+	if [[ $? != 0 ]]; then
+		echo "Memory window $MW did not match!" >&2
+	fi
+
+	if [[ "$A" == "/tmp/*" ]]; then
+		rm "$A"
+	fi
+
+	if [[ "$B" == "/tmp/*" ]]; then
+		rm "$B"
+	fi
+
+	echo "  Passed"
+}
+
+function pingpong_test()
+{
+	LOC=$1
+	REM=$2
+
+	echo "Running ping pong tests on: $(basename $LOC) / $(basename $REM)"
+
+	LOC_START=$(read_file $LOC/count)
+	REM_START=$(read_file $REM/count)
+
+	sleep 7
+
+	LOC_END=$(read_file $LOC/count)
+	REM_END=$(read_file $REM/count)
+
+	if [[ $LOC_START == $LOC_END ]] || [[ $REM_START == $REM_END ]]; then
+		echo "Ping pong counter not incrementing!" >&2
+		exit 1
+	fi
+
+	echo "  Passed"
+}
+
+function perf_test()
+{
+	USE_DMA=$1
+
+	if [[ $USE_DMA == "1" ]]; then
+		WITH="with"
+	else
+		WITH="without"
+	fi
+
+	_modprobe ntb_perf run_order=$PERF_RUN_ORDER \
+		max_mw_size=$MAX_MW_SIZE use_dma=$USE_DMA
+
+	echo "Running local perf test $WITH DMA"
+	write_file "" $LOCAL_PERF/run
+	echo -n "  "
+	read_file $LOCAL_PERF/run
+	echo "  Passed"
+
+	echo "Running remote perf test $WITH DMA"
+	write_file "" $REMOTE_PERF/run
+	echo -n "  "
+	read_file $LOCAL_PERF/run
+	echo "  Passed"
+
+	_modprobe -r ntb_perf
+}
+
+function ntb_tool_tests()
+{
+	LOCAL_TOOL=$DEBUGFS/ntb_tool/$LOCAL_DEV
+	REMOTE_TOOL=$REMOTE_HOST:$DEBUGFS/ntb_tool/$REMOTE_DEV
+
+	echo "Starting ntb_tool tests..."
+
+	_modprobe ntb_tool
+
+	write_file Y $LOCAL_TOOL/link_event
+	write_file Y $REMOTE_TOOL/link_event
+
+	link_test $LOCAL_TOOL $REMOTE_TOOL
+	link_test $REMOTE_TOOL $LOCAL_TOOL
+
+	for PEER_TRANS in $(ls $LOCAL_TOOL/peer_trans*); do
+		PT=$(basename $PEER_TRANS)
+		write_file $MW_SIZE $LOCAL_TOOL/$PT
+		write_file $MW_SIZE $REMOTE_TOOL/$PT
+	done
+
+	doorbell_test $LOCAL_TOOL $REMOTE_TOOL
+	doorbell_test $REMOTE_TOOL $LOCAL_TOOL
+	scratchpad_test $LOCAL_TOOL $REMOTE_TOOL
+	scratchpad_test $REMOTE_TOOL $LOCAL_TOOL
+
+	for MW in $(ls $LOCAL_TOOL/mw*); do
+		MW=$(basename $MW)
+
+		mw_test $MW $LOCAL_TOOL $REMOTE_TOOL
+		mw_test $MW $REMOTE_TOOL $LOCAL_TOOL
+	done
+
+	_modprobe -r ntb_tool
+}
+
+function ntb_pingpong_tests()
+{
+	LOCAL_PP=$DEBUGFS/ntb_pingpong/$LOCAL_DEV
+	REMOTE_PP=$REMOTE_HOST:$DEBUGFS/ntb_pingpong/$REMOTE_DEV
+
+	echo "Starting ntb_pingpong tests..."
+
+	_modprobe ntb_pingpong
+
+	pingpong_test $LOCAL_PP $REMOTE_PP
+
+	_modprobe -r ntb_pingpong
+}
+
+function ntb_perf_tests()
+{
+	LOCAL_PERF=$DEBUGFS/ntb_perf/$LOCAL_DEV
+	REMOTE_PERF=$REMOTE_HOST:$DEBUGFS/ntb_perf/$REMOTE_DEV
+
+	echo "Starting ntb_perf tests..."
+
+	perf_test 0
+
+	if [[ $RUN_DMA_TESTS ]]; then
+		perf_test 1
+	fi
+}
+
+function cleanup()
+{
+	set +e
+	_modprobe -r ntb_tool 2> /dev/null
+	_modprobe -r ntb_perf 2> /dev/null
+	_modprobe -r ntb_pingpong 2> /dev/null
+	_modprobe -r ntb_transport 2> /dev/null
+	set -e
+}
+
+cleanup
+
+if ! [[ $$DONT_CLEANUP ]]; then
+	trap cleanup EXIT
+fi
+
+if [ "$(id -u)" != "0" ]; then
+	echo "This script must be run as root" 1>&2
+	exit 1
+fi
+
+if [[ "$LIST_DEVS" == TRUE ]]; then
+	echo "Local Devices:"
+	ls -1 /sys/bus/ntb/devices
+	echo
+
+	if [[ "$REMOTE_HOST" != "" ]]; then
+		echo "Remote Devices:"
+		ssh $REMOTE_HOST ls -1 /sys/bus/ntb/devices
+	fi
+
+	exit 0
+fi
+
+if [[ "$LOCAL_DEV" == $"" ]] || [[ "$REMOTE_DEV" == $"" ]]; then
+	show_help
+	exit 1
+fi
+
+ntb_tool_tests
+echo
+ntb_pingpong_tests
+echo
+ntb_perf_tests
+echo
--

2.1.4

#14 lore raw

Re: [PATCH v3 09/10] ntb_test: Add a selftest script for the NTB subsystem

Quoted 13 lines · Allen Hubbe

tools/testing/selftests/ntb/ntb_test.sh line 132

Quoted 10 lines
tools/testing/selftests/ntb/ntb_test.sh new file +10 -0
+function link_test()
+{
+	LOC=$1
+	REM=$2
+	EXP=0
+
+	echo "Running link tests on: $(basename $LOC) / $(basename $REM)"
+
+	write_file "N" "$LOC/link"
+	write_file "N" "$LOC/link_event"

If it fails to bring down the link, won't it just block waiting on link_event and never make it to the next step of the test?

Quoted 10 lines

tools/testing/selftests/ntb/ntb_test.sh line 142

Quoted 10 lines
tools/testing/selftests/ntb/ntb_test.sh new file +10 -0
+	if [[ $(read_file "$REM/link") != "N" ]]; then
+		echo "Expected remote link to be down in $REM/link" >&2
+		exit -1
+	fi
+
+	write_file "Y" "$LOC/link"
+	write_file "Y" "$LOC/link_event"
+
+	echo "  Passed"
+}

Well, the test is really intended to ensure both sides of the link see changes to the link status. If the driver is somehow buggy and the link never goes down/up when requested there's little I can do here except block forever. Unless we want to add a timeout to the link_event file (which I'd rather not).

You'd have the same issue if, when bringing the link up for the first time, the link does not come back.

Logan

#15 lore raw

RE: [PATCH v3 09/10] ntb_test: Add a selftest script for the NTB subsystem

From: Logan Gunthorpe

Quoted 32 lines · Allen Hubbe
Quoted 4 lines
Quoted 4 lines
tools/testing/selftests/ntb/ntb_test.sh new file +4 -0
+function link_test()
+{
+	LOC=$1
+	REM=$2
Quoted 8 lines

tools/testing/selftests/ntb/ntb_test.sh line 132

Quoted 6 lines
tools/testing/selftests/ntb/ntb_test.sh new file +6 -0
+	EXP=0
+
+	echo "Running link tests on: $(basename $LOC) / $(basename $REM)"
+
+	write_file "N" "$LOC/link"
+	write_file "N" "$LOC/link_event"

If it fails to bring down the link, won't it just block waiting on link_event and never

make it to the next step of the test?

Quoted 11 lines

tools/testing/selftests/ntb/ntb_test.sh line 142

Quoted 11 lines
tools/testing/selftests/ntb/ntb_test.sh new file +10 -0
+	if [[ $(read_file "$REM/link") != "N" ]]; then
+		echo "Expected remote link to be down in $REM/link" >&2
+		exit -1
+	fi
+
+	write_file "Y" "$LOC/link"
+	write_file "Y" "$LOC/link_event"
+
+	echo "  Passed"
+}

Well, the test is really intended to ensure both sides of the link see changes to the link status. If the driver is somehow buggy and the link never goes down/up when requested there's little I can do here except block forever. Unless we want to add a timeout to the link_event file (which I'd rather not).

Quoted 2 lines

You'd have the same issue if, when bringing the link up for the first time, the link does not come back.

The link might come up, but this test checks if the link can be forced down.

This test should fail on Intel RP/TB topology (two cpu sharing one ntb). The link state is the link state of the secondary side pcie bus connected to the secondary side cpu. The link must be up in order for the secondary side cpu to discover the ntb device, so the driver does not allow the link to be disabled in such topology.

A simple thing to do here might be:

write_file "N" "$LOC/link"
sleep 1
read_file "$REM/link"

You already have my Ack. This minor issue can be fixed later if anyone cares. I don't think it is a big deal, just worth pointing out that the script will hang here instead of report a failure. If it is worth fixing later, at that point we might also want to change this script to continue with other tests instead of exit on the first failure.

#16 lore raw

Re: [PATCH v3 09/10] ntb_test: Add a selftest script for the NTB subsystem

Quoted 1 line · Allen Hubbe

This test should fail on Intel RP/TB topology (two cpu sharing one ntb). The link state is the link state of the secondary side pcie bus connected to the secondary side cpu. The link must be up in order for the secondary side cpu to discover the ntb device, so the driver does not allow the link to be disabled in such topology.

Ok, I wasn't aware of this. But looking closer I think I have a better solution:

ntb_link_disable should return -EINVAL if the hardware can't support bringing the link down. If I add the error check to my tool_link_write (which I neglected to do) then writing an "N" to $LOC/link will fail and the test could be skipped. I'll make a v4 spin.

Logan

Quoted 8 lines

A simple thing to do here might be:

write_file "N" "$LOC/link"
sleep 1
read_file "$REM/link"

You already have my Ack. This minor issue can be fixed later if anyone cares. I don't think it is a big deal, just worth pointing out that the script will hang here instead of report a failure. If it is worth fixing later, at that point we might also want to change this script to continue with other tests instead of exit on the first failure.

#17 lore raw

PATCH v3 10/10 ntb_perf: clear link_is_up flag when the link goes down.

In reply to Logan Gunthorpe

When the link goes down, the link_is_up flag did not return to false. This could have caused some subtle corner case bugs when the link goes up and down quickly.

---
 drivers/ntb/test/ntb_perf.c | 2 ++
 1 file changed, 2 insertions(+)
drivers/ntb/test/ntb_perf.c +2 -0
index f0784e5..ae9d1b2 100644
@@ -557,6 +557,8 @@ static void perf_link_cleanup(struct work_struct *work)
 
 	if (!perf->link_is_up)
 		cancel_delayed_work_sync(&perf->link_work);
+
+	perf->link_is_up = false;
 }
 
 static int perf_setup_mw(struct ntb_dev *ntb, struct perf_ctx *perf)
Signature · 1 line
2.1.4
maintainer Acked-by on v3 10/10
#18 lore raw

Re: [PATCH v3 10/10] ntb_perf: clear link_is_up flag when the link goes down.

Quoted 5 lines · Logan Gunthorpe

When the link goes down, the link_is_up flag did not return to false. This could have caused some subtle corner case bugs when the link goes up and down quickly.

And all the other ntb_perf patches since there were no additional changes.

Quoted 22 lines

---
 drivers/ntb/test/ntb_perf.c | 2 ++

 1 file changed, 2 insertions(+)
drivers/ntb/test/ntb_perf.c +0 -0
index f0784e5..ae9d1b2 100644
@@ -557,6 +557,8 @@ static void perf_link_cleanup(struct work_struct
 *work)


  if (!perf->link_is_up) cancel_delayed_work_sync(&perf->link_work);

drivers/ntb/test/ntb_perf.c +2 -0
+
+	perf->link_is_up = false;

 }

 static int perf_setup_mw(struct ntb_dev *ntb, struct perf_ctx *perf) --
2.1.4

#19 lore raw

Re: [PATCH v3 10/10] ntb_perf: clear link_is_up flag when the link goes down.

Hey,

Actually, I have to retract this patch. After some more thorough testing I'm finding an issue:

When you remove and re-install the ntb_perf module very quickly, ntb_perf will occasionally miss the link up event. This is because the link_cleanup work gets delayed long enough that it gets scheduled after the link up event gets sent. It then cancels the link work that should have occurred. Without this patch, it never happens because link_is_up never returns to false.

I think the correct solution is to just remove the link_cleanup work and do those actions immediately on receipt of the event. If there's agreement on this I can re-spin it again.

Thanks,

Logan

Quoted 33 lines · Dave
Quoted 5 lines · Logan Gunthorpe

When the link goes down, the link_is_up flag did not return to false. This could have caused some subtle corner case bugs when the link goes up and down quickly.

And all the other ntb_perf patches since there were no additional changes.

Quoted 21 lines
---
 drivers/ntb/test/ntb_perf.c | 2 ++
 1 file changed, 2 insertions(+)
drivers/ntb/test/ntb_perf.c +2 -0
index f0784e5..ae9d1b2 100644
@@ -557,6 +557,8 @@ static void perf_link_cleanup(struct work_struct
 *work)
 
 	if (!perf->link_is_up)
 		cancel_delayed_work_sync(&perf->link_work);
+
+	perf->link_is_up = false;
 }
 

static int perf_setup_mw(struct ntb_dev *ntb, struct perf_ctx *perf)

Signature · 1 line
2.1.4
maintainer
#20 lore raw

Re: [PATCH v3 10/10] ntb_perf: clear link_is_up flag when the link goes down.

Quoted 17 lines · Logan Gunthorpe

Hey,

Actually, I have to retract this patch. After some more thorough testing
I'm finding an issue:

When you remove and re-install the ntb_perf module very quickly, ntb_perf will occasionally miss the link up event. This is because the
link_cleanup work gets delayed long enough that it gets scheduled after
the link up event gets sent. It then cancels the link work that should
have occurred. Without this patch, it never happens because link_is_up
never returns to false.

Quoted 4 lines

I think the correct solution is to just remove the link_cleanup work and
do those actions immediately on receipt of the event. If there's agreement on this I can re-spin it again.

I'm ok with that. This is not an issue with ntb_transport?

Quoted 44 lines

Thanks,

Logan

Quoted 37 lines · Dave
Quoted 6 lines · Logan Gunthorpe

When the link goes down, the link_is_up flag did not return to false. This could have caused some subtle corner case bugs when the link goes up and down quickly.

And all the other ntb_perf patches since there were no additional changes.

Quoted 24 lines

---
 drivers/ntb/test/ntb_perf.c | 2 ++

 1 file changed, 2 insertions(+)
drivers/ntb/test/ntb_perf.c +0 -0
index f0784e5..ae9d1b2 100644
@@ -557,6 +557,8 @@ static void perf_link_cleanup(struct

work_struct
*work)

  if (!perf->link_is_up) cancel_delayed_work_sync(&perf->link_work);

drivers/ntb/test/ntb_perf.c +2 -0
+
+	perf->link_is_up = false;

 }

 static int perf_setup_mw(struct ntb_dev *ntb, struct perf_ctx *perf)
--
2.1.4

#21 lore raw

Re: [PATCH v3 10/10] ntb_perf: clear link_is_up flag when the link goes down.

Hey,

Quoted 18 lines · Dave
Quoted 17 lines · Logan Gunthorpe

Hey,

Actually, I have to retract this patch. After some more thorough testing
I'm finding an issue:

When you remove and re-install the ntb_perf module very quickly, ntb_perf will occasionally miss the link up event. This is because the
link_cleanup work gets delayed long enough that it gets scheduled after
the link up event gets sent. It then cancels the link work that should
have occurred. Without this patch, it never happens because link_is_up
never returns to false.

Quoted 6 lines
Quoted 4 lines

I think the correct solution is to just remove the link_cleanup work and
do those actions immediately on receipt of the event. If there's agreement on this I can re-spin it again.

I'm ok with that. This is not an issue with ntb_transport?

Looks like I can get something similar to happen in ntb_transport. However, it's much rarer and takes significantly more tries to get it to occur. It does appear to correctly set its link_is_up to false when the link goes down.

I'm not sure I'm quite clear on the flow in ntb_transport and don't have time right now to study it so I'll have to let that be someone else's (fairly minor) issue.

Logan