github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-11-07 06:17:02 +01:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

dmaengine: add union chan_dev for dma_chan::dev for clarity

Browse Source 
The current dma_chan structure contains both "device" and "dev". So

chan->device->dev refers to the DMA engine device.
chan->dev->device refers to the per-channel device instance.

Their similar naming makes the distinction unclear and increases reader
confusion.

Add union dma_chan::chan_dev to make its purpose explicit and clearly
identify it as the per-channel device. After all user switch to chan_dev,
union and dma_chan::dev will be removed.

Update the kernel-doc accordingly. Besides its sysfs usage, the per-channel
device is also used by some DMA engine drivers for IOMMU mapping and
therefore deserves a more accurate description.

No functional change intended.

Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20260909-dma-chan_dev-rename-v4-4-d8fb6892a70f@nxp.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
This commit is contained in:
Frank Li 2026-09-09 12:22:31 -04:00 committed by Vinod Koul
parent 3b97a3ec42
commit 6ad1b49cc3
4 changed files with 23 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
drivers/dma/dmaengine.c
View File

@ -1083,8 +1083,8 @@ static int __dma_async_device_channel_register(struct dma_device *device,
chan->local = alloc_percpu(typeof(*chan->local));
if (!chan->local)
return -ENOMEM;
chan->dev = kzalloc_obj(*chan->dev);
if (!chan->dev) {
chan->chan_dev = kzalloc_obj(*chan->chan_dev);
if (!chan->chan_dev) {
rc = -ENOMEM;
goto err_free_local;
}
@ -1103,8 +1103,8 @@ static int __dma_async_device_channel_register(struct dma_device *device,
dmaengine_chan_dev(chan)->class = &dma_devclass;
dmaengine_chan_dev(chan)->parent = device->dev;
chan->dev->chan = chan;
chan->dev->dev_id = device->dev_id;
chan->chan_dev->chan = chan;
chan->chan_dev->dev_id = device->dev_id;
spin_lock_init(&chan->lock);
if (!name)
@ -1122,7 +1122,7 @@ static int __dma_async_device_channel_register(struct dma_device *device,
err_out_ida:
ida_free(&device->chan_ida, chan->chan_id);
err_free_dev:
kfree(chan->dev);
kfree(chan->chan_dev);
err_free_local:
free_percpu(chan->local);
chan->local = NULL;
@ -1155,7 +1155,7 @@ static void __dma_async_device_channel_unregister(struct dma_device *device,
__func__, chan->client_count);
mutex_lock(&dma_list_mutex);
device->chancnt--;
chan->dev->chan = NULL;
chan->chan_dev->chan = NULL;
mutex_unlock(&dma_list_mutex);
ida_free(&device->chan_ida, chan->chan_id);
device_unregister(dmaengine_chan_dev(chan));
@ -1290,7 +1290,7 @@ int dma_async_device_register(struct dma_device *device)
if (chan->local == NULL)
continue;
mutex_lock(&dma_list_mutex);
chan->dev->chan = NULL;
chan->chan_dev->chan = NULL;
mutex_unlock(&dma_list_mutex);
device_unregister(dmaengine_chan_dev(chan));
free_percpu(chan->local);

2
drivers/dma/tegra186-gpc-dma.c
View File

@ -1554,7 +1554,7 @@ static int tegra_dma_probe(struct platform_device *pdev)
return dev_err_probe(chdev, -EINVAL,
"Failed to get stream ID for channel %d\n", tdc->id);
chan->dev->chan_dma_dev = true;
chan->chan_dev->chan_dma_dev = true;
}
/* program stream-id for this channel */

4
drivers/dma/ti/k3-udma.c
View File

@ -426,12 +426,12 @@ static void k3_configure_chan_coherency(struct dma_chan *chan, u32 asel)
if (asel == 0) {
/* No special handling for the channel */
chan->dev->chan_dma_dev = false;
chan->chan_dev->chan_dma_dev = false;
dev_clear_dma_coherent(chan_dev);
chan_dev->dma_parms = NULL;
} else if (asel == 14 || asel == 15) {
chan->dev->chan_dma_dev = true;
chan->chan_dev->chan_dma_dev = true;
dev_set_dma_coherent(chan_dev);
dma_coerce_mask_and_coherent(chan_dev, DMA_BIT_MASK(48));

18
include/linux/dmaengine.h
View File

@ -325,7 +325,8 @@ struct dma_router {
* @lock: protect between config and prepare transfer when driver have not
* implemented callback device_prep_config_sg().
* @chan_id: channel ID for sysfs
* @dev: class device for sysfs
* @chan_dev: class channel device for sysfs, some device use it for per-channel
* IOMMU mapping.
* @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"
@ -351,7 +352,14 @@ struct dma_chan {
/* sysfs */
int chan_id;
struct dma_chan_dev *dev;
union {
struct dma_chan_dev *chan_dev;
/*
* Use chan_dev; dev will be removed once all users are
* converted.
*/
struct dma_chan_dev *dev;
};
const char *name;
#ifdef CONFIG_DEBUG_FS
char *dbg_client_name;
@ -532,7 +540,7 @@ struct dma_slave_caps {
static inline const char *dma_chan_name(struct dma_chan *chan)
{
return dev_name(&chan->dev->device);
return dev_name(&chan->chan_dev->device);
}
/**
@ -1805,12 +1813,12 @@ dmaengine_get_direction_text(enum dma_transfer_direction dir)
static inline struct device *dmaengine_chan_dev(struct dma_chan *chan)
{
return &chan->dev->device;
return &chan->chan_dev->device;
}
static inline struct device *dmaengine_get_dma_device(struct dma_chan *chan)
{
if (chan->dev->chan_dma_dev)
if (chan->chan_dev->chan_dma_dev)
return dmaengine_chan_dev(chan);
return chan->device->dev;