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| author |   Peter Ujfalusi <peter.ujfalusi@ti.com> | 2020-03-06 16:28:37 +0200 |
|---|---|---|
| committer |   Vinod Koul <vkoul@kernel.org> | 2020-03-11 14:55:10 +0530 |
| commit | e937cc1dd7966df33a478943817302502a164e25 (patch) | |
| tree | 99240566bf0ca814bfa1567525abf3119d4faf40 /include/linux/dmaengine.h | |
| parent | dmaengine: fsl-dpaa2-qdma: remove set but not used variable 'dpaa2_qdma' (diff) | |
| download | wireguard-linux-e937cc1dd7966df33a478943817302502a164e25.tar.xz wireguard-linux-e937cc1dd7966df33a478943817302502a164e25.zip | |
dmaengine: Add basic debugfs support
Via the /sys/kernel/debug/dmaengine/summary users can get information
about the DMA devices and the used channels.
Example output on am654-evm with audio using two channels and after running
dmatest on 4 channels:
dma0 (285c0000.dma-controller): number of channels: 96
dma1 (31150000.dma-controller): number of channels: 267
dma1chan0 | 2b00000.mcasp:tx
dma1chan1 | 2b00000.mcasp:rx
dma1chan2 | in-use
dma1chan3 | in-use
dma1chan4 | in-use
dma1chan5 | in-use
For slave channels we can show the device and the channel name a given
channel is requested.
For non slave devices the only information we know is that the channel is
in use.
DMA drivers can implement the optional dbg_summary_show callback to
provide controller specific information instead of the generic one.
It is easy to extend the generic dmaengine_summary_show() to print
additional information about the used channels.
I have taken the idea from gpiolib and clk subsystems.
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Link: https://lore.kernel.org/r/20200306142839.17910-2-peter.ujfalusi@ti.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'include/linux/dmaengine.h')
| -rw-r--r-- | include/linux/dmaengine.h | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h index d3672f065a64..72920b5cf2d7 100644 --- a/include/linux/dmaengine.h +++ b/include/linux/dmaengine.h @@ -300,6 +300,8 @@ struct dma_router { * @chan_id: channel ID for sysfs * @dev: class device for sysfs * @name: backlink name for sysfs + * @dbg_client_name: slave name for debugfs in format: + * dev_name(requester's dev):channel name, for example: "2b00000.mcasp:tx" * @device_node: used to add this to the device chan list * @local: per-cpu pointer to a struct dma_chan_percpu * @client_count: how many clients are using this channel @@ -318,6 +320,9 @@ struct dma_chan { int chan_id; struct dma_chan_dev *dev; const char *name; +#ifdef CONFIG_DEBUG_FS + char *dbg_client_name; +#endif struct list_head device_node; struct dma_chan_percpu __percpu *local; @@ -806,7 +811,9 @@ struct dma_filter { * called and there are no further references to this structure. This * must be implemented to free resources however many existing drivers * do not and are therefore not safe to unbind while in use. - * + * @dbg_summary_show: optional routine to show contents in debugfs; default code + * will be used when this is omitted, but custom code can show extra, + * controller specific information. */ struct dma_device { struct kref ref; @@ -892,6 +899,10 @@ struct dma_device { struct dma_tx_state *txstate); void (*device_issue_pending)(struct dma_chan *chan); void (*device_release)(struct dma_device *dev); + /* debugfs support */ +#ifdef CONFIG_DEBUG_FS + void (*dbg_summary_show)(struct seq_file *s, struct dma_device *dev); +#endif }; static inline int dmaengine_slave_config(struct dma_chan *chan, |