[PATCH v2 00/11] dmaengine: kill off dma_slave_config->slave_id
From: Arnd Bergmann arnd@arndb.de
I recently came across some new uses of the 'slave_id' field that I had (almost) removed a few years ago. There are no legitimate uses of this field in the kernel, only a few stale references and two drivers that abuse the field as a side-channel between the dmaengine driver and its client.
Let's change the xilinx and qualcomm drivers to use the documented side-channel (peripheral_data) instead, and remove the remnants of it to prevent new users from coming in.
I think I got all the necessary Acks on v1 already, so if there are no further concerns, please merge this through the dmaengine tree for v5.17, or pull from
git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic.git tags/dma-slave-id-removal
Arnd
Arnd Bergmann (13): ASoC: tegra20-spdif: stop setting slave_id ASoC: dai_dma: remove slave_id field spi: pic32: stop setting dma_config->slave_id mmc: bcm2835: stop setting chan_config->slave_id dmaengine: shdma: remove legacy slave_id parsing dmaengine: pxa/mmp: stop referencing config->slave_id dmaengine: sprd: stop referencing config->slave_id dmaengine: qcom-adm: stop abusing slave_id config dmaengine: xilinx_dpdma: stop using slave_id field dmaengine: tegra20-apb: stop checking config->slave_id dmaengine: remove slave_id config field
--- Changes in v2:
- drop obsolete drivers/staging/patch - split tegra change into a separate patch - improve some patch descriptions.
drivers/dma/mmp_pdma.c | 6 --- drivers/dma/pxa_dma.c | 7 ---- drivers/dma/qcom/qcom_adm.c | 56 ++++++++++++++++++++++---- drivers/dma/sh/shdma-base.c | 8 ---- drivers/dma/sprd-dma.c | 3 -- drivers/dma/tegra20-apb-dma.c | 6 --- drivers/dma/xilinx/xilinx_dpdma.c | 17 +++++--- drivers/gpu/drm/xlnx/zynqmp_disp.c | 9 ++++- drivers/mmc/host/bcm2835.c | 2 - drivers/mtd/nand/raw/qcom_nandc.c | 14 ++++++- drivers/spi/spi-pic32.c | 2 - drivers/tty/serial/msm_serial.c | 15 ++++++- include/linux/dma/qcom_adm.h | 12 ++++++ include/linux/dma/xilinx_dpdma.h | 11 +++++ include/linux/dmaengine.h | 4 -- include/linux/platform_data/asoc-s3c.h | 6 --- include/sound/dmaengine_pcm.h | 4 -- sound/core/pcm_dmaengine.c | 26 +----------- sound/soc/tegra/tegra20_spdif.c | 1 - 27 files changed, 134 insertions(+), 146 deletions(-) create mode 100644 include/linux/dma/qcom_adm.h create mode 100644 include/linux/dma/xilinx_dpdma.h
From: Arnd Bergmann arnd@arndb.de
The DMA resource is never set up anywhere, and passing this as slave_id has not been the proper procedure in a long time.
As a preparation for removing all slave_id references from the ALSA code, remove this one.
According to Dmitry Osipenko, this driver has never been used and the mechanism for configuring DMA would not work as it is implemented, so this part will get rewritten when the driver gets put into use again in the future.
Signed-off-by: Arnd Bergmann arnd@arndb.de --- sound/soc/tegra/tegra20_spdif.c | 1 - 1 file changed, 1 deletion(-)
diff --git a/sound/soc/tegra/tegra20_spdif.c b/sound/soc/tegra/tegra20_spdif.c index 9fdc82d58db3..1c3385da6f82 100644 --- a/sound/soc/tegra/tegra20_spdif.c +++ b/sound/soc/tegra/tegra20_spdif.c @@ -284,7 +284,6 @@ static int tegra20_spdif_platform_probe(struct platform_device *pdev) spdif->playback_dma_data.addr = mem->start + TEGRA20_SPDIF_DATA_OUT; spdif->playback_dma_data.addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES; spdif->playback_dma_data.maxburst = 4; - spdif->playback_dma_data.slave_id = dmareq->start;
pm_runtime_enable(&pdev->dev);
From: Arnd Bergmann arnd@arndb.de
This field is no longer set from any driver now, so remove the last references as well.
Signed-off-by: Arnd Bergmann arnd@arndb.de --- include/sound/dmaengine_pcm.h | 2 -- sound/core/pcm_dmaengine.c | 5 ++--- 2 files changed, 2 insertions(+), 5 deletions(-)
diff --git a/include/sound/dmaengine_pcm.h b/include/sound/dmaengine_pcm.h index 9144bd547851..7403870c28bd 100644 --- a/include/sound/dmaengine_pcm.h +++ b/include/sound/dmaengine_pcm.h @@ -58,7 +58,6 @@ struct dma_chan *snd_dmaengine_pcm_get_chan(struct snd_pcm_substream *substream) * @maxburst: Maximum number of words(note: words, as in units of the * src_addr_width member, not bytes) that can be send to or received from the * DAI in one burst. - * @slave_id: Slave requester id for the DMA channel. * @filter_data: Custom DMA channel filter data, this will usually be used when * requesting the DMA channel. * @chan_name: Custom channel name to use when requesting DMA channel. @@ -72,7 +71,6 @@ struct snd_dmaengine_dai_dma_data { dma_addr_t addr; enum dma_slave_buswidth addr_width; u32 maxburst; - unsigned int slave_id; void *filter_data; const char *chan_name; unsigned int fifo_size; diff --git a/sound/core/pcm_dmaengine.c b/sound/core/pcm_dmaengine.c index af08bb4bf578..6762fb2083e1 100644 --- a/sound/core/pcm_dmaengine.c +++ b/sound/core/pcm_dmaengine.c @@ -91,8 +91,8 @@ EXPORT_SYMBOL_GPL(snd_hwparams_to_dma_slave_config); * @dma_data: DAI DMA data * @slave_config: DMA slave configuration * - * Initializes the {dst,src}_addr, {dst,src}_maxburst, {dst,src}_addr_width and - * slave_id fields of the DMA slave config from the same fields of the DAI DMA + * Initializes the {dst,src}_addr, {dst,src}_maxburst, {dst,src}_addr_width + * fields of the DMA slave config from the same fields of the DAI DMA * data struct. The src and dst fields will be initialized depending on the * direction of the substream. If the substream is a playback stream the dst * fields will be initialized, if it is a capture stream the src fields will be @@ -124,7 +124,6 @@ void snd_dmaengine_pcm_set_config_from_dai_data( slave_config->src_addr_width = dma_data->addr_width; }
- slave_config->slave_id = dma_data->slave_id; slave_config->peripheral_config = dma_data->peripheral_config; slave_config->peripheral_size = dma_data->peripheral_size; }
From: Arnd Bergmann arnd@arndb.de
Setting slave_id makes no sense with DT based probing, and should eventually get removed entirely. Address this driver by no longer setting the field here.
I could not find which DMA driver is used on PIC32, if it's in the tree at all, but none of the obvious ones even care about slave_id any more.
Acked-by: Mark Brown broonie@kernel.org Signed-off-by: Arnd Bergmann arnd@arndb.de --- drivers/spi/spi-pic32.c | 2 -- 1 file changed, 2 deletions(-)
diff --git a/drivers/spi/spi-pic32.c b/drivers/spi/spi-pic32.c index 5eb7b61bbb4d..f86433b29260 100644 --- a/drivers/spi/spi-pic32.c +++ b/drivers/spi/spi-pic32.c @@ -370,7 +370,6 @@ static int pic32_spi_dma_config(struct pic32_spi *pic32s, u32 dma_width) cfg.src_addr_width = dma_width; cfg.dst_addr_width = dma_width; /* tx channel */ - cfg.slave_id = pic32s->tx_irq; cfg.direction = DMA_MEM_TO_DEV; ret = dmaengine_slave_config(master->dma_tx, &cfg); if (ret) { @@ -378,7 +377,6 @@ static int pic32_spi_dma_config(struct pic32_spi *pic32s, u32 dma_width) return ret; } /* rx channel */ - cfg.slave_id = pic32s->rx_irq; cfg.direction = DMA_DEV_TO_MEM; ret = dmaengine_slave_config(master->dma_rx, &cfg); if (ret)
From: Arnd Bergmann arnd@arndb.de
The field is not interpreted by the DMA engine driver, as all the data is passed from devicetree instead. Remove the assignment so the field can eventually be deleted.
Reviewed-by: Nicolas Saenz Julienne nsaenz@kernel.org Signed-off-by: Arnd Bergmann arnd@arndb.de --- drivers/mmc/host/bcm2835.c | 2 -- 1 file changed, 2 deletions(-)
diff --git a/drivers/mmc/host/bcm2835.c b/drivers/mmc/host/bcm2835.c index 8c2361e66277..463b707d9e99 100644 --- a/drivers/mmc/host/bcm2835.c +++ b/drivers/mmc/host/bcm2835.c @@ -1293,14 +1293,12 @@ static int bcm2835_add_host(struct bcm2835_host *host)
host->dma_cfg_tx.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES; host->dma_cfg_tx.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES; - host->dma_cfg_tx.slave_id = 13; /* DREQ channel */ host->dma_cfg_tx.direction = DMA_MEM_TO_DEV; host->dma_cfg_tx.src_addr = 0; host->dma_cfg_tx.dst_addr = host->phys_addr + SDDATA;
host->dma_cfg_rx.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES; host->dma_cfg_rx.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES; - host->dma_cfg_rx.slave_id = 13; /* DREQ channel */ host->dma_cfg_rx.direction = DMA_DEV_TO_MEM; host->dma_cfg_rx.src_addr = host->phys_addr + SDDATA; host->dma_cfg_rx.dst_addr = 0;
On Mon, 22 Nov 2021 at 23:23, Arnd Bergmann arnd@kernel.org wrote:
From: Arnd Bergmann arnd@arndb.de
The field is not interpreted by the DMA engine driver, as all the data is passed from devicetree instead. Remove the assignment so the field can eventually be deleted.
Reviewed-by: Nicolas Saenz Julienne nsaenz@kernel.org Signed-off-by: Arnd Bergmann arnd@arndb.de
I think I acked the previous version, but nevermind:
Acked-by: Ulf Hansson ulf.hansson@linaro.org
Kind regards Uffe
drivers/mmc/host/bcm2835.c | 2 -- 1 file changed, 2 deletions(-)
diff --git a/drivers/mmc/host/bcm2835.c b/drivers/mmc/host/bcm2835.c index 8c2361e66277..463b707d9e99 100644 --- a/drivers/mmc/host/bcm2835.c +++ b/drivers/mmc/host/bcm2835.c @@ -1293,14 +1293,12 @@ static int bcm2835_add_host(struct bcm2835_host *host)
host->dma_cfg_tx.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES; host->dma_cfg_tx.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
host->dma_cfg_tx.slave_id = 13; /* DREQ channel */ host->dma_cfg_tx.direction = DMA_MEM_TO_DEV; host->dma_cfg_tx.src_addr = 0; host->dma_cfg_tx.dst_addr = host->phys_addr + SDDATA; host->dma_cfg_rx.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES; host->dma_cfg_rx.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;host->dma_cfg_rx.slave_id = 13; /* DREQ channel */ host->dma_cfg_rx.direction = DMA_DEV_TO_MEM; host->dma_cfg_rx.src_addr = host->phys_addr + SDDATA; host->dma_cfg_rx.dst_addr = 0;-- 2.29.2
From: Arnd Bergmann arnd@arndb.de
The slave device is picked through either devicetree or a filter function, and any remaining out-of-tree drivers would have warned about this usage since 2015.
Stop interpreting the field finally so it can be removed from the interface.
Reviewed-by: Laurent Pinchart laurent.pinchart@ideasonboard.com Signed-off-by: Arnd Bergmann arnd@arndb.de --- drivers/dma/sh/shdma-base.c | 8 -------- 1 file changed, 8 deletions(-)
diff --git a/drivers/dma/sh/shdma-base.c b/drivers/dma/sh/shdma-base.c index 7f72b3f4cd1a..41c6bc650fa3 100644 --- a/drivers/dma/sh/shdma-base.c +++ b/drivers/dma/sh/shdma-base.c @@ -786,14 +786,6 @@ static int shdma_config(struct dma_chan *chan, if (!config) return -EINVAL;
- /* - * overriding the slave_id through dma_slave_config is deprecated, - * but possibly some out-of-tree drivers still do it. - */ - if (WARN_ON_ONCE(config->slave_id && - config->slave_id != schan->real_slave_id)) - schan->real_slave_id = config->slave_id; - /* * We could lock this, but you shouldn't be configuring the * channel, while using it...
From: Arnd Bergmann arnd@arndb.de
The last driver referencing the slave_id on Marvell PXA and MMP platforms was the SPI driver, but this stopped doing so a long time ago, so the TODO from the earlier patch can no be removed.
Fixes: b729bf34535e ("spi/pxa2xx: Don't use slave_id of dma_slave_config") Fixes: 13b3006b8ebd ("dma: mmp_pdma: add filter function") Signed-off-by: Arnd Bergmann arnd@arndb.de --- drivers/dma/mmp_pdma.c | 6 ------ drivers/dma/pxa_dma.c | 7 ------- 2 files changed, 13 deletions(-)
diff --git a/drivers/dma/mmp_pdma.c b/drivers/dma/mmp_pdma.c index a23563cd118b..5a53d7fcef01 100644 --- a/drivers/dma/mmp_pdma.c +++ b/drivers/dma/mmp_pdma.c @@ -727,12 +727,6 @@ static int mmp_pdma_config_write(struct dma_chan *dchan,
chan->dir = direction; chan->dev_addr = addr; - /* FIXME: drivers should be ported over to use the filter - * function. Once that's done, the following two lines can - * be removed. - */ - if (cfg->slave_id) - chan->drcmr = cfg->slave_id;
return 0; } diff --git a/drivers/dma/pxa_dma.c b/drivers/dma/pxa_dma.c index 52d04641e361..6078cc81892e 100644 --- a/drivers/dma/pxa_dma.c +++ b/drivers/dma/pxa_dma.c @@ -909,13 +909,6 @@ static void pxad_get_config(struct pxad_chan *chan, *dcmd |= PXA_DCMD_BURST16; else if (maxburst == 32) *dcmd |= PXA_DCMD_BURST32; - - /* FIXME: drivers should be ported over to use the filter - * function. Once that's done, the following two lines can - * be removed. - */ - if (chan->cfg.slave_id) - chan->drcmr = chan->cfg.slave_id; }
static struct dma_async_tx_descriptor *
From: Arnd Bergmann arnd@arndb.de
It appears that the code that reads the slave_id from the channel config was copied incorrectly from other drivers. Nothing ever sets this field on platforms that use this driver, so remove the reference.
Reviewed-by: Baolin Wang baolin.wang7@gmail.com Signed-off-by: Arnd Bergmann arnd@arndb.de --- drivers/dma/sprd-dma.c | 3 --- 1 file changed, 3 deletions(-)
diff --git a/drivers/dma/sprd-dma.c b/drivers/dma/sprd-dma.c index 4357d2395e6b..7f158ef5672d 100644 --- a/drivers/dma/sprd-dma.c +++ b/drivers/dma/sprd-dma.c @@ -795,9 +795,6 @@ static int sprd_dma_fill_desc(struct dma_chan *chan, return dst_datawidth; }
- if (slave_cfg->slave_id) - schan->dev_id = slave_cfg->slave_id; - hw->cfg = SPRD_DMA_DONOT_WAIT_BDONE << SPRD_DMA_WAIT_BDONE_OFFSET;
/*
From: Arnd Bergmann arnd@arndb.de
The slave_id was previously used to pick one DMA slave instead of another, but this is now done through the DMA descriptors in device tree.
For the qcom_adm driver, the configuration is documented in the DT binding to contain a tuple of device identifier and a "crci" field, but the implementation ends up using only a single cell for identifying the slave, with the crci getting passed in nonstandard properties of the device, and passed through the dma driver using the old slave_id field. Part of the problem apparently is that the nand driver ends up using only a single DMA request ID, but requires distinct values for "crci" depending on the type of transfer.
Change both the dmaengine driver and the two slave drivers to allow the documented binding to work in addition to the ad-hoc passing of crci values. In order to no longer abuse the slave_id field, pass the data using the "peripheral_config" mechanism instead.
Signed-off-by: Arnd Bergmann arnd@arndb.de --- drivers/dma/qcom/qcom_adm.c | 56 +++++++++++++++++++++++++++---- drivers/mtd/nand/raw/qcom_nandc.c | 14 ++++++-- drivers/tty/serial/msm_serial.c | 15 +++++++-- include/linux/dma/qcom_adm.h | 12 +++++++ 4 files changed, 86 insertions(+), 11 deletions(-) create mode 100644 include/linux/dma/qcom_adm.h
diff --git a/drivers/dma/qcom/qcom_adm.c b/drivers/dma/qcom/qcom_adm.c index ee78bed8d60d..bb338b303af6 100644 --- a/drivers/dma/qcom/qcom_adm.c +++ b/drivers/dma/qcom/qcom_adm.c @@ -8,6 +8,7 @@ #include <linux/device.h> #include <linux/dmaengine.h> #include <linux/dma-mapping.h> +#include <linux/dma/qcom_adm.h> #include <linux/init.h> #include <linux/interrupt.h> #include <linux/io.h> @@ -140,6 +141,8 @@ struct adm_chan {
struct adm_async_desc *curr_txd; struct dma_slave_config slave; + u32 crci; + u32 mux; struct list_head node;
int error; @@ -379,8 +382,8 @@ static struct dma_async_tx_descriptor *adm_prep_slave_sg(struct dma_chan *chan, return ERR_PTR(-EINVAL); }
- crci = achan->slave.slave_id & 0xf; - if (!crci || achan->slave.slave_id > 0x1f) { + crci = achan->crci & 0xf; + if (!crci || achan->crci > 0x1f) { dev_err(adev->dev, "invalid crci value\n"); return ERR_PTR(-EINVAL); } @@ -403,9 +406,7 @@ static struct dma_async_tx_descriptor *adm_prep_slave_sg(struct dma_chan *chan, if (!async_desc) return ERR_PTR(-ENOMEM);
- if (crci) - async_desc->mux = achan->slave.slave_id & ADM_CRCI_MUX_SEL ? - ADM_CRCI_CTL_MUX_SEL : 0; + async_desc->mux = achan->mux ? ADM_CRCI_CTL_MUX_SEL : 0; async_desc->crci = crci; async_desc->blk_size = blk_size; async_desc->dma_len = single_count * sizeof(struct adm_desc_hw_single) + @@ -488,10 +489,13 @@ static int adm_terminate_all(struct dma_chan *chan) static int adm_slave_config(struct dma_chan *chan, struct dma_slave_config *cfg) { struct adm_chan *achan = to_adm_chan(chan); + struct qcom_adm_peripheral_config *config = cfg->peripheral_config; unsigned long flag;
spin_lock_irqsave(&achan->vc.lock, flag); memcpy(&achan->slave, cfg, sizeof(struct dma_slave_config)); + if (cfg->peripheral_size == sizeof(config)) + achan->crci = config->crci; spin_unlock_irqrestore(&achan->vc.lock, flag);
return 0; @@ -694,6 +698,45 @@ static void adm_channel_init(struct adm_device *adev, struct adm_chan *achan, achan->vc.desc_free = adm_dma_free_desc; }
+/** + * adm_dma_xlate + * @dma_spec: pointer to DMA specifier as found in the device tree + * @ofdma: pointer to DMA controller data + * + * This can use either 1-cell or 2-cell formats, the first cell + * identifies the slave device, while the optional second cell + * contains the crci value. + * + * Returns pointer to appropriate dma channel on success or NULL on error. + */ +struct dma_chan *adm_dma_xlate(struct of_phandle_args *dma_spec, + struct of_dma *ofdma) +{ + struct dma_device *dev = ofdma->of_dma_data; + struct dma_chan *chan, *candidate = NULL; + struct adm_chan *achan; + + if (!dev || dma_spec->args_count > 2) + return NULL; + + list_for_each_entry(chan, &dev->channels, device_node) + if (chan->chan_id == dma_spec->args[0]) { + candidate = chan; + break; + } + + if (!candidate) + return NULL; + + achan = to_adm_chan(candidate); + if (dma_spec->args_count == 2) + achan->crci = dma_spec->args[1]; + else + achan->crci = 0; + + return dma_get_slave_channel(candidate); +} + static int adm_dma_probe(struct platform_device *pdev) { struct adm_device *adev; @@ -838,8 +881,7 @@ static int adm_dma_probe(struct platform_device *pdev) goto err_disable_clks; }
- ret = of_dma_controller_register(pdev->dev.of_node, - of_dma_xlate_by_chan_id, + ret = of_dma_controller_register(pdev->dev.of_node, adm_dma_xlate, &adev->common); if (ret) goto err_unregister_dma; diff --git a/drivers/mtd/nand/raw/qcom_nandc.c b/drivers/mtd/nand/raw/qcom_nandc.c index 04e6f7b26706..7c6efa3b6255 100644 --- a/drivers/mtd/nand/raw/qcom_nandc.c +++ b/drivers/mtd/nand/raw/qcom_nandc.c @@ -6,6 +6,7 @@ #include <linux/clk.h> #include <linux/slab.h> #include <linux/bitops.h> +#include <linux/dma/qcom_adm.h> #include <linux/dma-mapping.h> #include <linux/dmaengine.h> #include <linux/module.h> @@ -952,6 +953,7 @@ static int prep_adm_dma_desc(struct qcom_nand_controller *nandc, bool read, struct dma_async_tx_descriptor *dma_desc; struct scatterlist *sgl; struct dma_slave_config slave_conf; + struct qcom_adm_peripheral_config periph_conf = {}; enum dma_transfer_direction dir_eng; int ret;
@@ -983,11 +985,19 @@ static int prep_adm_dma_desc(struct qcom_nand_controller *nandc, bool read, if (read) { slave_conf.src_maxburst = 16; slave_conf.src_addr = nandc->base_dma + reg_off; - slave_conf.slave_id = nandc->data_crci; + if (nandc->data_crci) { + periph_conf.crci = nandc->data_crci; + slave_conf.peripheral_config = &periph_conf; + slave_conf.peripheral_size = sizeof(periph_conf); + } } else { slave_conf.dst_maxburst = 16; slave_conf.dst_addr = nandc->base_dma + reg_off; - slave_conf.slave_id = nandc->cmd_crci; + if (nandc->cmd_crci) { + periph_conf.crci = nandc->cmd_crci; + slave_conf.peripheral_config = &periph_conf; + slave_conf.peripheral_size = sizeof(periph_conf); + } }
ret = dmaengine_slave_config(nandc->chan, &slave_conf); diff --git a/drivers/tty/serial/msm_serial.c b/drivers/tty/serial/msm_serial.c index fcef7a961430..c6be09f44dc1 100644 --- a/drivers/tty/serial/msm_serial.c +++ b/drivers/tty/serial/msm_serial.c @@ -9,6 +9,7 @@
#include <linux/kernel.h> #include <linux/atomic.h> +#include <linux/dma/qcom_adm.h> #include <linux/dma-mapping.h> #include <linux/dmaengine.h> #include <linux/module.h> @@ -290,6 +291,7 @@ static void msm_request_tx_dma(struct msm_port *msm_port, resource_size_t base) { struct device *dev = msm_port->uart.dev; struct dma_slave_config conf; + struct qcom_adm_peripheral_config periph_conf = {}; struct msm_dma *dma; u32 crci = 0; int ret; @@ -308,7 +310,11 @@ static void msm_request_tx_dma(struct msm_port *msm_port, resource_size_t base) conf.device_fc = true; conf.dst_addr = base + UARTDM_TF; conf.dst_maxburst = UARTDM_BURST_SIZE; - conf.slave_id = crci; + if (crci) { + conf.peripheral_config = &periph_conf; + conf.peripheral_size = sizeof(periph_conf); + periph_conf.crci = crci; + }
ret = dmaengine_slave_config(dma->chan, &conf); if (ret) @@ -333,6 +339,7 @@ static void msm_request_rx_dma(struct msm_port *msm_port, resource_size_t base) { struct device *dev = msm_port->uart.dev; struct dma_slave_config conf; + struct qcom_adm_peripheral_config periph_conf = {}; struct msm_dma *dma; u32 crci = 0; int ret; @@ -355,7 +362,11 @@ static void msm_request_rx_dma(struct msm_port *msm_port, resource_size_t base) conf.device_fc = true; conf.src_addr = base + UARTDM_RF; conf.src_maxburst = UARTDM_BURST_SIZE; - conf.slave_id = crci; + if (crci) { + conf.peripheral_config = &periph_conf; + conf.peripheral_size = sizeof(periph_conf); + periph_conf.crci = crci; + }
ret = dmaengine_slave_config(dma->chan, &conf); if (ret) diff --git a/include/linux/dma/qcom_adm.h b/include/linux/dma/qcom_adm.h new file mode 100644 index 000000000000..af20df674f0c --- /dev/null +++ b/include/linux/dma/qcom_adm.h @@ -0,0 +1,12 @@ +// SPDX-License-Identifier: GPL-2.0-only +#ifndef __LINUX_DMA_QCOM_ADM_H +#define __LINUX_DMA_QCOM_ADM_H + +#include <linux/types.h> + +struct qcom_adm_peripheral_config { + u32 crci; + u32 mux; +}; + +#endif /* __LINUX_DMA_QCOM_ADM_H */
From: Arnd Bergmann arnd@arndb.de
The display driver wants to pass a custom flag to the DMA engine driver, which it started doing by using the slave_id field that was traditionally used for a different purpose.
As there is no longer a correct use for the slave_id field, it should really be removed, and the remaining users changed over to something different.
The new mechanism for passing nonstandard settings is using the .peripheral_config field, so use that to pass a newly defined structure here, making it clear that this will not work in portable drivers.
Reviewed-by: Laurent Pinchart laurent.pinchart@ideasonboard.com Signed-off-by: Arnd Bergmann arnd@arndb.de --- drivers/dma/xilinx/xilinx_dpdma.c | 17 +++++++++++------ drivers/gpu/drm/xlnx/zynqmp_disp.c | 9 +++++++-- include/linux/dma/xilinx_dpdma.h | 11 +++++++++++ 3 files changed, 29 insertions(+), 8 deletions(-) create mode 100644 include/linux/dma/xilinx_dpdma.h
diff --git a/drivers/dma/xilinx/xilinx_dpdma.c b/drivers/dma/xilinx/xilinx_dpdma.c index ce5c66e6897d..b0f4948b00a5 100644 --- a/drivers/dma/xilinx/xilinx_dpdma.c +++ b/drivers/dma/xilinx/xilinx_dpdma.c @@ -12,6 +12,7 @@ #include <linux/clk.h> #include <linux/debugfs.h> #include <linux/delay.h> +#include <linux/dma/xilinx_dpdma.h> #include <linux/dmaengine.h> #include <linux/dmapool.h> #include <linux/interrupt.h> @@ -1273,6 +1274,7 @@ static int xilinx_dpdma_config(struct dma_chan *dchan, struct dma_slave_config *config) { struct xilinx_dpdma_chan *chan = to_xilinx_chan(dchan); + struct xilinx_dpdma_peripheral_config *pconfig; unsigned long flags;
/* @@ -1282,15 +1284,18 @@ static int xilinx_dpdma_config(struct dma_chan *dchan, * fixed both on the DPDMA side and on the DP controller side. */
- spin_lock_irqsave(&chan->lock, flags); - /* - * Abuse the slave_id to indicate that the channel is part of a video - * group. + * Use the peripheral_config to indicate that the channel is part + * of a video group. This requires matching use of the custom + * structure in each driver. */ - if (chan->id <= ZYNQMP_DPDMA_VIDEO2) - chan->video_group = config->slave_id != 0; + pconfig = config->peripheral_config; + if (WARN_ON(pconfig && config->peripheral_size != sizeof(*pconfig))) + return -EINVAL;
+ spin_lock_irqsave(&chan->lock, flags); + if (chan->id <= ZYNQMP_DPDMA_VIDEO2 && pconfig) + chan->video_group = pconfig->video_group; spin_unlock_irqrestore(&chan->lock, flags);
return 0; diff --git a/drivers/gpu/drm/xlnx/zynqmp_disp.c b/drivers/gpu/drm/xlnx/zynqmp_disp.c index ff2b308d8651..11c409cbc88e 100644 --- a/drivers/gpu/drm/xlnx/zynqmp_disp.c +++ b/drivers/gpu/drm/xlnx/zynqmp_disp.c @@ -24,6 +24,7 @@
#include <linux/clk.h> #include <linux/delay.h> +#include <linux/dma/xilinx_dpdma.h> #include <linux/dma-mapping.h> #include <linux/dmaengine.h> #include <linux/module.h> @@ -1058,14 +1059,18 @@ static void zynqmp_disp_layer_set_format(struct zynqmp_disp_layer *layer, zynqmp_disp_avbuf_set_format(layer->disp, layer, layer->disp_fmt);
/* - * Set slave_id for each DMA channel to indicate they're part of a + * Set pconfig for each DMA channel to indicate they're part of a * video group. */ for (i = 0; i < info->num_planes; i++) { struct zynqmp_disp_layer_dma *dma = &layer->dmas[i]; + struct xilinx_dpdma_peripheral_config pconfig = { + .video_group = true, + }; struct dma_slave_config config = { .direction = DMA_MEM_TO_DEV, - .slave_id = 1, + .peripheral_config = &pconfig, + .peripheral_size = sizeof(pconfig), };
dmaengine_slave_config(dma->chan, &config); diff --git a/include/linux/dma/xilinx_dpdma.h b/include/linux/dma/xilinx_dpdma.h new file mode 100644 index 000000000000..83a1377f03f8 --- /dev/null +++ b/include/linux/dma/xilinx_dpdma.h @@ -0,0 +1,11 @@ +// SPDX-License-Identifier: GPL-2.0 +#ifndef __LINUX_DMA_XILINX_DPDMA_H +#define __LINUX_DMA_XILINX_DPDMA_H + +#include <linux/types.h> + +struct xilinx_dpdma_peripheral_config { + bool video_group; +}; + +#endif /* __LINUX_DMA_XILINX_DPDMA_H */
From: Arnd Bergmann arnd@arndb.de
Nothing sets the slave_id field any more, so stop accessing it to allow the removal of this field.
Signed-off-by: Arnd Bergmann arnd@arndb.de --- drivers/dma/tegra20-apb-dma.c | 6 ------ 1 file changed, 6 deletions(-)
diff --git a/drivers/dma/tegra20-apb-dma.c b/drivers/dma/tegra20-apb-dma.c index b7260749e8ee..eaafcbe4ca94 100644 --- a/drivers/dma/tegra20-apb-dma.c +++ b/drivers/dma/tegra20-apb-dma.c @@ -343,12 +343,6 @@ static int tegra_dma_slave_config(struct dma_chan *dc, }
memcpy(&tdc->dma_sconfig, sconfig, sizeof(*sconfig)); - if (tdc->slave_id == TEGRA_APBDMA_SLAVE_ID_INVALID && - sconfig->device_fc) { - if (sconfig->slave_id > TEGRA_APBDMA_CSR_REQ_SEL_MASK) - return -EINVAL; - tdc->slave_id = sconfig->slave_id; - } tdc->config_init = true;
return 0;
From: Arnd Bergmann arnd@arndb.de
All references to the slave_id field have been removed, so remove the field as well to prevent new references from creeping in again.
Originally this allowed slave DMA drivers to configure which device is accessed with the dmaengine_slave_config() call, but this was inconsistent, as the same information is also passed while requesting a channel, and never changes in practice.
In modern kernels, the device is always selected when requesting the channel, so the .slave_id field is no longer useful.
Reviewed-by: Laurent Pinchart laurent.pinchart@ideasonboard.com Signed-off-by: Arnd Bergmann arnd@arndb.de --- include/linux/dmaengine.h | 4 ---- 1 file changed, 4 deletions(-)
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h index 9000f3ffce8b..0349b35235e6 100644 --- a/include/linux/dmaengine.h +++ b/include/linux/dmaengine.h @@ -418,9 +418,6 @@ enum dma_slave_buswidth { * @device_fc: Flow Controller Settings. Only valid for slave channels. Fill * with 'true' if peripheral should be flow controller. Direction will be * selected at Runtime. - * @slave_id: Slave requester id. Only valid for slave channels. The dma - * slave peripheral will have unique id as dma requester which need to be - * pass as slave config. * @peripheral_config: peripheral configuration for programming peripheral * for dmaengine transfer * @peripheral_size: peripheral configuration buffer size @@ -448,7 +445,6 @@ struct dma_slave_config { u32 src_port_window_size; u32 dst_port_window_size; bool device_fc; - unsigned int slave_id; void *peripheral_config; size_t peripheral_size; };
On Mon, Nov 22, 2021 at 11:21:52PM +0100, Arnd Bergmann wrote:
From: Arnd Bergmann arnd@arndb.de
I recently came across some new uses of the 'slave_id' field that I had (almost) removed a few years ago. There are no legitimate uses of this field in the kernel, only a few stale references and two drivers that abuse the field as a side-channel between the dmaengine driver and its client.
Acked-by: Mark Brown broonie@kernel.org
participants (3)
-
Arnd Bergmann -
Mark Brown -
Ulf Hansson