This patch adds debugfs support to report stats via debugfs
which in-turn will help debug hang situations.
Signed-off-by: Anup Patel <anup.patel@xxxxxxxxxxxx>
Reviewed-by: Ray Jui <ray.jui@xxxxxxxxxxxx>
Reviewed-by: Scott Branden <scott.branden@xxxxxxxxxxxx>
---
drivers/dma/bcm-sba-raid.c | 82 +++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 81 insertions(+), 1 deletion(-)
diff --git a/drivers/dma/bcm-sba-raid.c b/drivers/dma/bcm-sba-raid.c
index b92c756..dd1e89e 100644
--- a/drivers/dma/bcm-sba-raid.c
+++ b/drivers/dma/bcm-sba-raid.c
@@ -36,6 +36,7 @@
*/
#include <linux/bitops.h>
+#include <linux/debugfs.h>
#include <linux/dma-mapping.h>
#include <linux/dmaengine.h>
#include <linux/list.h>
@@ -161,6 +162,9 @@ struct sba_device {
struct list_head reqs_completed_list;
struct list_head reqs_aborted_list;
struct list_head reqs_free_list;
+ /* DebugFS directory entries */
+ struct dentry *root;
+ struct dentry *stats;
};
/* ====== Command helper routines ===== */
@@ -485,6 +489,45 @@ static void sba_process_received_request(struct sba_device *sba,
}
}
+static void sba_write_stats_in_seqfile(struct sba_device *sba,
+ struct seq_file *file)
+{
+ unsigned long flags;
+ struct sba_request *req;
+ u32 free_count = 0, alloced_count = 0, pending_count = 0;
+ u32 active_count = 0, aborted_count = 0, completed_count = 0;
+
+ spin_lock_irqsave(&sba->reqs_lock, flags);
+
+ list_for_each_entry(req, &sba->reqs_free_list, node)
+ free_count++;
+
+ list_for_each_entry(req, &sba->reqs_alloc_list, node)
+ alloced_count++;
+
+ list_for_each_entry(req, &sba->reqs_pending_list, node)
+ pending_count++;
+
+ list_for_each_entry(req, &sba->reqs_active_list, node)
+ active_count++;
+
+ list_for_each_entry(req, &sba->reqs_aborted_list, node)
+ aborted_count++;
+
+ list_for_each_entry(req, &sba->reqs_completed_list, node)
+ completed_count++;
+
+ spin_unlock_irqrestore(&sba->reqs_lock, flags);
+
+ seq_printf(file, "maximum requests = %d\n", sba->max_req);
+ seq_printf(file, "free requests = %d\n", free_count);
+ seq_printf(file, "alloced requests = %d\n", alloced_count);
+ seq_printf(file, "pending requests = %d\n", pending_count);
+ seq_printf(file, "active requests = %d\n", active_count);
+ seq_printf(file, "aborted requests = %d\n", aborted_count);
+ seq_printf(file, "completed requests = %d\n", completed_count);
+}
+
/* ====== DMAENGINE callbacks ===== */
static void sba_free_chan_resources(struct dma_chan *dchan)
@@ -1450,6 +1493,19 @@ static void sba_receive_message(struct mbox_client *cl, void *msg)
sba_process_received_request(sba, req);
}
+/* ====== Debugfs callbacks ====== */
+
+static int sba_debugfs_stats_show(struct seq_file *file, void *offset)
+{
+ struct platform_device *pdev = to_platform_device(file->private);
+ struct sba_device *sba = platform_get_drvdata(pdev);
+
+ /* Write stats in file */
+ sba_write_stats_in_seqfile(sba, file);
+
+ return 0;
+}
+
/* ====== Platform driver routines ===== */
static int sba_prealloc_channel_resources(struct sba_device *sba)
@@ -1721,10 +1777,30 @@ static int sba_probe(struct platform_device *pdev)
if (ret)
goto fail_free_mchans;
+ /* Check availability of debugfs */
+ if (!debugfs_initialized())
+ goto skip_debugfs;
+
+ /* Create debugfs root entry */
+ sba->root = debugfs_create_dir(dev_name(sba->dev), NULL);
+ if (IS_ERR_OR_NULL(sba->root)) {
+ ret = PTR_ERR_OR_ZERO(sba->root);
+ goto fail_free_resources;
+ }
+
+ /* Create debugfs stats entry */
+ sba->stats = debugfs_create_devm_seqfile(sba->dev, "stats", sba->root,
+ sba_debugfs_stats_show);
+ if (IS_ERR_OR_NULL(sba->stats)) {
+ ret = PTR_ERR_OR_ZERO(sba->stats);
+ goto fail_free_debugfs_root;
+ }
+skip_debugfs:
+
/* Register DMA device with linux async framework */
ret = sba_async_register(sba);
if (ret)
- goto fail_free_resources;
+ goto fail_free_debugfs_root;
/* Print device info */
dev_info(sba->dev, "%s using SBAv%d and %d mailbox channels",
@@ -1733,6 +1809,8 @@ static int sba_probe(struct platform_device *pdev)
return 0;
+fail_free_debugfs_root:
+ debugfs_remove_recursive(sba->root);
fail_free_resources:
sba_freeup_channel_resources(sba);
fail_free_mchans:
@@ -1748,6 +1826,8 @@ static int sba_remove(struct platform_device *pdev)
dma_async_device_unregister(&sba->dma_dev);
+ debugfs_remove_recursive(sba->root);
+
sba_freeup_channel_resources(sba);
for (i = 0; i < sba->mchans_count; i++)
--
2.7.4
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