From: Frank Li <[email protected]> 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 <[email protected]> Signed-off-by: Frank Li <[email protected]> --- there are other user use it outside drivers/dma/ directory. --- drivers/dma/dmaengine.c | 14 +++++++------- drivers/dma/tegra186-gpc-dma.c | 2 +- drivers/dma/ti/k3-udma.c | 4 ++-- include/linux/dmaengine.h | 18 +++++++++++++----- 4 files changed, 23 insertions(+), 15 deletions(-) diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c index a7ac2729e4d9d..bb30a9aa54d3f 100644 --- a/drivers/dma/dmaengine.c +++ b/drivers/dma/dmaengine.c @@ -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); diff --git a/drivers/dma/tegra186-gpc-dma.c b/drivers/dma/tegra186-gpc-dma.c index b3327aa35de40..e76c58f213d84 100644 --- a/drivers/dma/tegra186-gpc-dma.c +++ b/drivers/dma/tegra186-gpc-dma.c @@ -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 */ diff --git a/drivers/dma/ti/k3-udma.c b/drivers/dma/ti/k3-udma.c index 49e2d0014d5ed..78a67cb9d6e00 100644 --- a/drivers/dma/ti/k3-udma.c +++ b/drivers/dma/ti/k3-udma.c @@ -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)); diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h index 33aa1bfc8fb84..206c5dab96cd7 100644 --- a/include/linux/dmaengine.h +++ b/include/linux/dmaengine.h @@ -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; + /* + * please use chan_dev, dev will be removed after all user + switch to chan_dev + */ + 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; -- 2.43.0
