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* [PATCH] dmaengine: pl330: introduce debugfs interface
@ 2019-03-14 18:49 Katsuhiro Suzuki
  2019-03-15 17:00 ` Vinod Koul
  0 siblings, 1 reply; 5+ messages in thread
From: Katsuhiro Suzuki @ 2019-03-14 18:49 UTC (permalink / raw)
  To: Vinod Koul, dmaengine; +Cc: linux-kernel, Katsuhiro Suzuki

This patch adds debugfs interface to show the relationship between
DMA threads (hardware resource for transferring data) and DMA
channel ID of DMA slave.

Typically, PL330 has many slaves than number of DMA threads.
So sometimes PL330 cannot allocate DMA threads for all slaves even
if an user specify DMA channel ID in devicetree. This interface will
be useful for checking that DMA threads are allocated or not.

Below is an output sample:

$ sudo cat /sys/kernel/debug/ff1f0000.dmac
PL330 physical channels:
THREAD:         CHANNEL:
--------        -----
0               8
1               9
2               11
3               12
4               14
5               15
6               10
7               --

Signed-off-by: Katsuhiro Suzuki <katsuhiro@katsuster.net>
---
 drivers/dma/pl330.c | 51 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 51 insertions(+)

diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
index eec79fdf27a5..aab71863757c 100644
--- a/drivers/dma/pl330.c
+++ b/drivers/dma/pl330.c
@@ -11,6 +11,7 @@
  * (at your option) any later version.
  */
 
+#include <linux/debugfs.h>
 #include <linux/kernel.h>
 #include <linux/io.h>
 #include <linux/init.h>
@@ -2896,6 +2897,55 @@ static irqreturn_t pl330_irq_handler(int irq, void *data)
 	BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) | \
 	BIT(DMA_SLAVE_BUSWIDTH_8_BYTES)
 
+#ifdef CONFIG_DEBUG_FS
+static int pl330_debugfs_show(struct seq_file *s, void *data)
+{
+	struct pl330_dmac *pl330 = s->private;
+	int chans, pchs, ch, pr, found;
+
+	chans = pl330->pcfg.num_chan;
+	pchs = pl330->num_peripherals;
+
+	seq_puts(s, "PL330 physical channels:\n");
+	seq_puts(s, "THREAD:\t\tCHANNEL:\n");
+	seq_puts(s, "--------\t-----\n");
+	for (ch = 0; ch < chans; ch++) {
+		struct pl330_thread *thrd = &pl330->channels[ch];
+
+		found = -1;
+		for (pr = 0; pr < pchs; pr++) {
+			struct dma_pl330_chan *pch = &pl330->peripherals[pr];
+
+			if (!pch->thread || thrd->id != pch->thread->id)
+				continue;
+
+			found = pr;
+		}
+
+		seq_printf(s, "%d\t\t", thrd->id);
+		if (found == -1)
+			seq_puts(s, "--\n");
+		else
+			seq_printf(s, "%d\n", found);
+	}
+
+	return 0;
+}
+
+DEFINE_SHOW_ATTRIBUTE(pl330_debugfs);
+
+static inline void init_pl330_debugfs(struct pl330_dmac *pl330)
+{
+	debugfs_create_file(dev_name(pl330->ddma.dev),
+			    S_IFREG | S_IRUGO, NULL, pl330,
+			    &pl330_debugfs_fops);
+}
+#else
+static inline void init_pl330_debugfs(struct pl330_dmac *pl330)
+{
+}
+#endif
+
 /*
  * Runtime PM callbacks are provided by amba/bus.c driver.
  *
@@ -3082,6 +3132,7 @@ pl330_probe(struct amba_device *adev, const struct amba_id *id)
 		dev_err(&adev->dev, "unable to set the seg size\n");
 
 
+	init_pl330_debugfs(pl330);
 	dev_info(&adev->dev,
 		"Loaded driver for PL330 DMAC-%x\n", adev->periphid);
 	dev_info(&adev->dev,
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 5+ messages in thread
* [PATCH] dmaengine: pl330: introduce debugfs interface
@ 2019-03-17 10:00 Katsuhiro Suzuki
  2019-03-17 10:02 ` Katsuhiro Suzuki
  0 siblings, 1 reply; 5+ messages in thread
From: Katsuhiro Suzuki @ 2019-03-17 10:00 UTC (permalink / raw)
  To: Vinod Koul, dmaengine; +Cc: linux-kernel, Katsuhiro Suzuki

This patch adds debugfs interface to show the relationship between
DMA threads (hardware resource for transferring data) and DMA
channel ID of DMA slave.

Typically, PL330 has many slaves than number of DMA threads.
So sometimes PL330 cannot allocate DMA threads for all slaves even
if a user specify DMA channel ID in devicetree. This interface will
be useful for checking that DMA threads are allocated or not.

Below is an output sample:

$ sudo cat /sys/kernel/debug/ff1f0000.dmac
PL330 physical channels:
THREAD:         CHANNEL:
--------        -----
0               8
1               9
2               11
3               12
4               14
5               15
6               10
7               --

Signed-off-by: Katsuhiro Suzuki <katsuhiro@katsuster.net>
---
 drivers/dma/pl330.c | 51 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 51 insertions(+)

diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
index eec79fdf27a5..c72f6fd79c43 100644
--- a/drivers/dma/pl330.c
+++ b/drivers/dma/pl330.c
@@ -11,6 +11,7 @@
  * (at your option) any later version.
  */
 
+#include <linux/debugfs.h>
 #include <linux/kernel.h>
 #include <linux/io.h>
 #include <linux/init.h>
@@ -2896,6 +2897,55 @@ static irqreturn_t pl330_irq_handler(int irq, void *data)
 	BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) | \
 	BIT(DMA_SLAVE_BUSWIDTH_8_BYTES)
 
+#ifdef CONFIG_DEBUG_FS
+static int pl330_debugfs_show(struct seq_file *s, void *data)
+{
+	struct pl330_dmac *pl330 = s->private;
+	int chans, pchs, ch, pr;
+
+	chans = pl330->pcfg.num_chan;
+	pchs = pl330->num_peripherals;
+
+	seq_puts(s, "PL330 physical channels:\n");
+	seq_puts(s, "THREAD:\t\tCHANNEL:\n");
+	seq_puts(s, "--------\t-----\n");
+	for (ch = 0; ch < chans; ch++) {
+		struct pl330_thread *thrd = &pl330->channels[ch];
+		int found = -1;
+
+		for (pr = 0; pr < pchs; pr++) {
+			struct dma_pl330_chan *pch = &pl330->peripherals[pr];
+
+			if (!pch->thread || thrd->id != pch->thread->id)
+				continue;
+
+			found = pr;
+		}
+
+		seq_printf(s, "%d\t\t", thrd->id);
+		if (found == -1)
+			seq_puts(s, "--\n");
+		else
+			seq_printf(s, "%d\n", found);
+	}
+
+	return 0;
+}
+
+DEFINE_SHOW_ATTRIBUTE(pl330_debugfs);
+
+static inline void init_pl330_debugfs(struct pl330_dmac *pl330)
+{
+	debugfs_create_file(dev_name(pl330->ddma.dev),
+			    S_IFREG | 0444, NULL, pl330,
+			    &pl330_debugfs_fops);
+}
+#else
+static inline void init_pl330_debugfs(struct pl330_dmac *pl330)
+{
+}
+#endif
+
 /*
  * Runtime PM callbacks are provided by amba/bus.c driver.
  *
@@ -3082,6 +3132,7 @@ pl330_probe(struct amba_device *adev, const struct amba_id *id)
 		dev_err(&adev->dev, "unable to set the seg size\n");
 
 
+	init_pl330_debugfs(pl330);
 	dev_info(&adev->dev,
 		"Loaded driver for PL330 DMAC-%x\n", adev->periphid);
 	dev_info(&adev->dev,
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2019-03-17 10:02 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-03-14 18:49 [PATCH] dmaengine: pl330: introduce debugfs interface Katsuhiro Suzuki
2019-03-15 17:00 ` Vinod Koul
2019-03-17  9:58   ` Katsuhiro Suzuki
2019-03-17 10:00 Katsuhiro Suzuki
2019-03-17 10:02 ` Katsuhiro Suzuki

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