4.4-stable review patch. If anyone has any objections, please let me know.
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From: Arnd Bergmann arnd@arndb.de
commit 1873315fb156cbc8e46f28e8b128f17ff6c31728 upstream.
By convention, the FIFO address we pass using dmaengine_slave_config is a physical address in the form that is understood by the DMA engine, as a dma_addr_t, phys_addr_t or resource_size_t.
The sh_flctl driver however passes a virtual __iomem address that gets cast to dma_addr_t in the slave driver. This happens to work on shmobile because that platform sets up an identity mapping for its MMIO regions, but such code is not portable to other platforms, and prevents us from ever changing the platform mapping or reusing the driver on other architectures like ARM64 that might not have the mapping.
We also get a warning about a type mismatch for the case that dma_addr_t is wider than a pointer, i.e. when CONFIG_LPAE is set:
drivers/mtd/nand/sh_flctl.c: In function 'flctl_setup_dma': drivers/mtd/nand/sh_flctl.c:163:17: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast] cfg.dst_addr = (dma_addr_t)FLDTFIFO(flctl);
This changes the driver to instead pass the physical address of the FIFO that is extracted from the MMIO resource, making the code more portable and avoiding the warning.
Signed-off-by: Arnd Bergmann arnd@arndb.de Signed-off-by: Brian Norris computersforpeace@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/mtd/nand/sh_flctl.c | 5 +++-- include/linux/mtd/sh_flctl.h | 1 + 2 files changed, 4 insertions(+), 2 deletions(-)
--- a/drivers/mtd/nand/sh_flctl.c +++ b/drivers/mtd/nand/sh_flctl.c @@ -160,7 +160,7 @@ static void flctl_setup_dma(struct sh_fl
memset(&cfg, 0, sizeof(cfg)); cfg.direction = DMA_MEM_TO_DEV; - cfg.dst_addr = (dma_addr_t)FLDTFIFO(flctl); + cfg.dst_addr = flctl->fifo; cfg.src_addr = 0; ret = dmaengine_slave_config(flctl->chan_fifo0_tx, &cfg); if (ret < 0) @@ -176,7 +176,7 @@ static void flctl_setup_dma(struct sh_fl
cfg.direction = DMA_DEV_TO_MEM; cfg.dst_addr = 0; - cfg.src_addr = (dma_addr_t)FLDTFIFO(flctl); + cfg.src_addr = flctl->fifo; ret = dmaengine_slave_config(flctl->chan_fifo0_rx, &cfg); if (ret < 0) goto err; @@ -1096,6 +1096,7 @@ static int flctl_probe(struct platform_d flctl->reg = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(flctl->reg)) return PTR_ERR(flctl->reg); + flctl->fifo = res->start + 0x24; /* FLDTFIFO */
irq = platform_get_irq(pdev, 0); if (irq < 0) { --- a/include/linux/mtd/sh_flctl.h +++ b/include/linux/mtd/sh_flctl.h @@ -148,6 +148,7 @@ struct sh_flctl { struct platform_device *pdev; struct dev_pm_qos_request pm_qos; void __iomem *reg; + resource_size_t fifo;
uint8_t done_buff[2048 + 64]; /* max size 2048 + 64 */ int read_bytes;