From f51f288e237cbcfd3dbd1d4fa2d3dec00d7253e2 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 22 May 2017 10:58:49 +0200 Subject: dma-mapping: remove DMA_ERROR_CODE And update the documentation - dma_mapping_error has been supported everywhere for a long time. Signed-off-by: Christoph Hellwig --- Documentation/DMA-API-HOWTO.txt | 31 +++++-------------------------- 1 file changed, 5 insertions(+), 26 deletions(-) (limited to 'Documentation') diff --git a/Documentation/DMA-API-HOWTO.txt b/Documentation/DMA-API-HOWTO.txt index 979228bc9035..4ed388356898 100644 --- a/Documentation/DMA-API-HOWTO.txt +++ b/Documentation/DMA-API-HOWTO.txt @@ -550,32 +550,11 @@ and to unmap it: dma_unmap_single(dev, dma_handle, size, direction); You should call dma_mapping_error() as dma_map_single() could fail and return -error. Not all DMA implementations support the dma_mapping_error() interface. -However, it is a good practice to call dma_mapping_error() interface, which -will invoke the generic mapping error check interface. Doing so will ensure -that the mapping code will work correctly on all DMA implementations without -any dependency on the specifics of the underlying implementation. Using the -returned address without checking for errors could result in failures ranging -from panics to silent data corruption. A couple of examples of incorrect ways -to check for errors that make assumptions about the underlying DMA -implementation are as follows and these are applicable to dma_map_page() as -well. - -Incorrect example 1: - dma_addr_t dma_handle; - - dma_handle = dma_map_single(dev, addr, size, direction); - if ((dma_handle & 0xffff != 0) || (dma_handle >= 0x1000000)) { - goto map_error; - } - -Incorrect example 2: - dma_addr_t dma_handle; - - dma_handle = dma_map_single(dev, addr, size, direction); - if (dma_handle == DMA_ERROR_CODE) { - goto map_error; - } +error. Doing so will ensure that the mapping code will work correctly on all +DMA implementations without any dependency on the specifics of the underlying +implementation. Using the returned address without checking for errors could +result in failures ranging from panics to silent data corruption. The same +applies to dma_map_page() as well. You should call dma_unmap_single() when the DMA activity is finished, e.g., from the interrupt which told you that the DMA transfer is done. -- cgit v1.2.3 From 03b643866d889d6edc87cdcee2b3880b7879a441 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 12 Jun 2017 19:05:09 +0200 Subject: dma-mapping: remove dmam_free_noncoherent This function was never used since it was added. Signed-off-by: Christoph Hellwig Acked-by: Tejun Heo --- Documentation/driver-model/devres.txt | 1 - drivers/base/dma-mapping.c | 20 -------------------- include/linux/dma-mapping.h | 2 -- 3 files changed, 23 deletions(-) (limited to 'Documentation') diff --git a/Documentation/driver-model/devres.txt b/Documentation/driver-model/devres.txt index e72587fe477d..9070ff06b558 100644 --- a/Documentation/driver-model/devres.txt +++ b/Documentation/driver-model/devres.txt @@ -243,7 +243,6 @@ DMA dmam_alloc_noncoherent() dmam_declare_coherent_memory() dmam_free_coherent() - dmam_free_noncoherent() dmam_pool_create() dmam_pool_destroy() diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c index f3deb6af42ad..5940c9dace36 100644 --- a/drivers/base/dma-mapping.c +++ b/drivers/base/dma-mapping.c @@ -148,26 +148,6 @@ void *dmam_alloc_noncoherent(struct device *dev, size_t size, } EXPORT_SYMBOL(dmam_alloc_noncoherent); -/** - * dmam_free_coherent - Managed dma_free_noncoherent() - * @dev: Device to free noncoherent memory for - * @size: Size of allocation - * @vaddr: Virtual address of the memory to free - * @dma_handle: DMA handle of the memory to free - * - * Managed dma_free_noncoherent(). - */ -void dmam_free_noncoherent(struct device *dev, size_t size, void *vaddr, - dma_addr_t dma_handle) -{ - struct dma_devres match_data = { size, vaddr, dma_handle }; - - dma_free_noncoherent(dev, size, vaddr, dma_handle); - WARN_ON(!devres_destroy(dev, dmam_noncoherent_release, dmam_match, - &match_data)); -} -EXPORT_SYMBOL(dmam_free_noncoherent); - #ifdef CONFIG_HAVE_GENERIC_DMA_COHERENT static void dmam_coherent_decl_release(struct device *dev, void *res) diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index 527f2ed8c645..4038dd34afa3 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -736,8 +736,6 @@ extern void dmam_free_coherent(struct device *dev, size_t size, void *vaddr, dma_addr_t dma_handle); extern void *dmam_alloc_noncoherent(struct device *dev, size_t size, dma_addr_t *dma_handle, gfp_t gfp); -extern void dmam_free_noncoherent(struct device *dev, size_t size, void *vaddr, - dma_addr_t dma_handle); #ifdef CONFIG_HAVE_GENERIC_DMA_COHERENT extern int dmam_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr, -- cgit v1.2.3 From 63d36c95500400642f656ba1970980746cf437f3 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 12 Jun 2017 19:15:04 +0200 Subject: dma-mapping: replace dmam_alloc_noncoherent with dmam_alloc_attrs dmam_alloc_noncoherent is a trivial wrapper around dmam_alloc_attrs, that hardcodes one particular flag. Make the devres code more flexible by allowing the callers to pass arbitrary flags. Signed-off-by: Christoph Hellwig Acked-by: Tejun Heo --- Documentation/driver-model/devres.txt | 2 +- drivers/base/dma-mapping.c | 36 ++++++++++++++++------------------- drivers/video/fbdev/au1200fb.c | 5 +++-- include/linux/dma-mapping.h | 5 +++-- 4 files changed, 23 insertions(+), 25 deletions(-) (limited to 'Documentation') diff --git a/Documentation/driver-model/devres.txt b/Documentation/driver-model/devres.txt index 9070ff06b558..7e08c02b5393 100644 --- a/Documentation/driver-model/devres.txt +++ b/Documentation/driver-model/devres.txt @@ -240,7 +240,7 @@ CLOCK DMA dmam_alloc_coherent() - dmam_alloc_noncoherent() + dmam_alloc_attrs() dmam_declare_coherent_memory() dmam_free_coherent() dmam_pool_create() diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c index 5940c9dace36..10e7c022e8cf 100644 --- a/drivers/base/dma-mapping.c +++ b/drivers/base/dma-mapping.c @@ -22,20 +22,15 @@ struct dma_devres { size_t size; void *vaddr; dma_addr_t dma_handle; + unsigned long attrs; }; -static void dmam_coherent_release(struct device *dev, void *res) +static void dmam_release(struct device *dev, void *res) { struct dma_devres *this = res; - dma_free_coherent(dev, this->size, this->vaddr, this->dma_handle); -} - -static void dmam_noncoherent_release(struct device *dev, void *res) -{ - struct dma_devres *this = res; - - dma_free_noncoherent(dev, this->size, this->vaddr, this->dma_handle); + dma_free_attrs(dev, this->size, this->vaddr, this->dma_handle, + this->attrs); } static int dmam_match(struct device *dev, void *res, void *match_data) @@ -69,7 +64,7 @@ void *dmam_alloc_coherent(struct device *dev, size_t size, struct dma_devres *dr; void *vaddr; - dr = devres_alloc(dmam_coherent_release, sizeof(*dr), gfp); + dr = devres_alloc(dmam_release, sizeof(*dr), gfp); if (!dr) return NULL; @@ -104,35 +99,35 @@ void dmam_free_coherent(struct device *dev, size_t size, void *vaddr, struct dma_devres match_data = { size, vaddr, dma_handle }; dma_free_coherent(dev, size, vaddr, dma_handle); - WARN_ON(devres_destroy(dev, dmam_coherent_release, dmam_match, - &match_data)); + WARN_ON(devres_destroy(dev, dmam_release, dmam_match, &match_data)); } EXPORT_SYMBOL(dmam_free_coherent); /** - * dmam_alloc_non_coherent - Managed dma_alloc_noncoherent() + * dmam_alloc_attrs - Managed dma_alloc_attrs() * @dev: Device to allocate non_coherent memory for * @size: Size of allocation * @dma_handle: Out argument for allocated DMA handle * @gfp: Allocation flags + * @attrs: Flags in the DMA_ATTR_* namespace. * - * Managed dma_alloc_noncoherent(). Memory allocated using this - * function will be automatically released on driver detach. + * Managed dma_alloc_attrs(). Memory allocated using this function will be + * automatically released on driver detach. * * RETURNS: * Pointer to allocated memory on success, NULL on failure. */ -void *dmam_alloc_noncoherent(struct device *dev, size_t size, - dma_addr_t *dma_handle, gfp_t gfp) +void *dmam_alloc_attrs(struct device *dev, size_t size, dma_addr_t *dma_handle, + gfp_t gfp, unsigned long attrs) { struct dma_devres *dr; void *vaddr; - dr = devres_alloc(dmam_noncoherent_release, sizeof(*dr), gfp); + dr = devres_alloc(dmam_release, sizeof(*dr), gfp); if (!dr) return NULL; - vaddr = dma_alloc_noncoherent(dev, size, dma_handle, gfp); + vaddr = dma_alloc_attrs(dev, size, dma_handle, gfp, attrs); if (!vaddr) { devres_free(dr); return NULL; @@ -141,12 +136,13 @@ void *dmam_alloc_noncoherent(struct device *dev, size_t size, dr->vaddr = vaddr; dr->dma_handle = *dma_handle; dr->size = size; + dr->attrs = attrs; devres_add(dev, dr); return vaddr; } -EXPORT_SYMBOL(dmam_alloc_noncoherent); +EXPORT_SYMBOL(dmam_alloc_attrs); #ifdef CONFIG_HAVE_GENERIC_DMA_COHERENT diff --git a/drivers/video/fbdev/au1200fb.c b/drivers/video/fbdev/au1200fb.c index 6c2b2ca4a909..5f04b4096c42 100644 --- a/drivers/video/fbdev/au1200fb.c +++ b/drivers/video/fbdev/au1200fb.c @@ -1694,9 +1694,10 @@ static int au1200fb_drv_probe(struct platform_device *dev) /* Allocate the framebuffer to the maximum screen size */ fbdev->fb_len = (win->w[plane].xres * win->w[plane].yres * bpp) / 8; - fbdev->fb_mem = dmam_alloc_noncoherent(&dev->dev, + fbdev->fb_mem = dmam_alloc_attrs(&dev->dev, PAGE_ALIGN(fbdev->fb_len), - &fbdev->fb_phys, GFP_KERNEL); + &fbdev->fb_phys, GFP_KERNEL, + DMA_ATTR_NON_CONSISTENT); if (!fbdev->fb_mem) { print_err("fail to allocate frambuffer (size: %dK))", fbdev->fb_len / 1024); diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index 4038dd34afa3..843ab866e0f4 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -734,8 +734,9 @@ extern void *dmam_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_handle, gfp_t gfp); extern void dmam_free_coherent(struct device *dev, size_t size, void *vaddr, dma_addr_t dma_handle); -extern void *dmam_alloc_noncoherent(struct device *dev, size_t size, - dma_addr_t *dma_handle, gfp_t gfp); +extern void *dmam_alloc_attrs(struct device *dev, size_t size, + dma_addr_t *dma_handle, gfp_t gfp, + unsigned long attrs); #ifdef CONFIG_HAVE_GENERIC_DMA_COHERENT extern int dmam_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr, -- cgit v1.2.3 From 93228b44c33a572cb36cec2dbed42e9bdbc88d79 Mon Sep 17 00:00:00 2001 From: Vladimir Murzin Date: Mon, 26 Jun 2017 10:18:58 +0100 Subject: drivers: dma-coherent: Introduce default DMA pool This patch introduces default coherent DMA pool similar to default CMA area concept. To keep other users safe code kept under CONFIG_ARM. Cc: Michal Nazarewicz Cc: Marek Szyprowski Cc: Rob Herring Cc: Mark Rutland Cc: Greg Kroah-Hartman Suggested-by: Robin Murphy Tested-by: Benjamin Gaignard Tested-by: Andras Szemzo Tested-by: Alexandre TORGUE Signed-off-by: Vladimir Murzin Signed-off-by: Christoph Hellwig --- .../bindings/reserved-memory/reserved-memory.txt | 3 ++ drivers/base/dma-coherent.c | 59 +++++++++++++++++++--- 2 files changed, 55 insertions(+), 7 deletions(-) (limited to 'Documentation') diff --git a/Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt b/Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt index 3da0ebdba8d9..16291f2a4688 100644 --- a/Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt +++ b/Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt @@ -68,6 +68,9 @@ Linux implementation note: - If a "linux,cma-default" property is present, then Linux will use the region for the default pool of the contiguous memory allocator. +- If a "linux,dma-default" property is present, then Linux will use the + region for the default pool of the consistent DMA allocator. + Device node references to reserved memory ----------------------------------------- Regions in the /reserved-memory node may be referenced by other device diff --git a/drivers/base/dma-coherent.c b/drivers/base/dma-coherent.c index 99c969520f30..2ae24c28e70c 100644 --- a/drivers/base/dma-coherent.c +++ b/drivers/base/dma-coherent.c @@ -19,6 +19,15 @@ struct dma_coherent_mem { bool use_dev_dma_pfn_offset; }; +static struct dma_coherent_mem *dma_coherent_default_memory __ro_after_init; + +static inline struct dma_coherent_mem *dev_get_coherent_memory(struct device *dev) +{ + if (dev && dev->dma_mem) + return dev->dma_mem; + return dma_coherent_default_memory; +} + static inline dma_addr_t dma_get_device_base(struct device *dev, struct dma_coherent_mem * mem) { @@ -93,6 +102,9 @@ static void dma_release_coherent_memory(struct dma_coherent_mem *mem) static int dma_assign_coherent_memory(struct device *dev, struct dma_coherent_mem *mem) { + if (!dev) + return -ENODEV; + if (dev->dma_mem) return -EBUSY; @@ -171,15 +183,12 @@ EXPORT_SYMBOL(dma_mark_declared_memory_occupied); int dma_alloc_from_coherent(struct device *dev, ssize_t size, dma_addr_t *dma_handle, void **ret) { - struct dma_coherent_mem *mem; + struct dma_coherent_mem *mem = dev_get_coherent_memory(dev); int order = get_order(size); unsigned long flags; int pageno; int dma_memory_map; - if (!dev) - return 0; - mem = dev->dma_mem; if (!mem) return 0; @@ -233,7 +242,7 @@ EXPORT_SYMBOL(dma_alloc_from_coherent); */ int dma_release_from_coherent(struct device *dev, int order, void *vaddr) { - struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL; + struct dma_coherent_mem *mem = dev_get_coherent_memory(dev); if (mem && vaddr >= mem->virt_base && vaddr < (mem->virt_base + (mem->size << PAGE_SHIFT))) { @@ -267,7 +276,7 @@ EXPORT_SYMBOL(dma_release_from_coherent); int dma_mmap_from_coherent(struct device *dev, struct vm_area_struct *vma, void *vaddr, size_t size, int *ret) { - struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL; + struct dma_coherent_mem *mem = dev_get_coherent_memory(dev); if (mem && vaddr >= mem->virt_base && vaddr + size <= (mem->virt_base + (mem->size << PAGE_SHIFT))) { @@ -297,6 +306,8 @@ EXPORT_SYMBOL(dma_mmap_from_coherent); #include #include +static struct reserved_mem *dma_reserved_default_memory __initdata; + static int rmem_dma_device_init(struct reserved_mem *rmem, struct device *dev) { struct dma_coherent_mem *mem = rmem->priv; @@ -318,7 +329,8 @@ static int rmem_dma_device_init(struct reserved_mem *rmem, struct device *dev) static void rmem_dma_device_release(struct reserved_mem *rmem, struct device *dev) { - dev->dma_mem = NULL; + if (dev) + dev->dma_mem = NULL; } static const struct reserved_mem_ops rmem_dma_ops = { @@ -338,6 +350,12 @@ static int __init rmem_dma_setup(struct reserved_mem *rmem) pr_err("Reserved memory: regions without no-map are not yet supported\n"); return -EINVAL; } + + if (of_get_flat_dt_prop(node, "linux,dma-default", NULL)) { + WARN(dma_reserved_default_memory, + "Reserved memory: region for default DMA coherent area is redefined\n"); + dma_reserved_default_memory = rmem; + } #endif rmem->ops = &rmem_dma_ops; @@ -345,5 +363,32 @@ static int __init rmem_dma_setup(struct reserved_mem *rmem) &rmem->base, (unsigned long)rmem->size / SZ_1M); return 0; } + +static int __init dma_init_reserved_memory(void) +{ + const struct reserved_mem_ops *ops; + int ret; + + if (!dma_reserved_default_memory) + return -ENOMEM; + + ops = dma_reserved_default_memory->ops; + + /* + * We rely on rmem_dma_device_init() does not propagate error of + * dma_assign_coherent_memory() for "NULL" device. + */ + ret = ops->device_init(dma_reserved_default_memory, NULL); + + if (!ret) { + dma_coherent_default_memory = dma_reserved_default_memory->priv; + pr_info("DMA: default coherent area is set\n"); + } + + return ret; +} + +core_initcall(dma_init_reserved_memory); + RESERVEDMEM_OF_DECLARE(dma, "shared-dma-pool", rmem_dma_setup); #endif -- cgit v1.2.3