From cfced786969c2a3e1bca45d7055a00311d93ae6c Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 4 Jan 2019 18:20:05 +0100 Subject: [PATCH 01/21] dma-mapping: remove the default map_resource implementation Instead provide a proper implementation in the direct mapping code, and also wire it up for arm and powerpc, leaving an error return for all the IOMMU or virtual mapping instances for which we'd have to wire up an actual implementation Signed-off-by: Christoph Hellwig Tested-by: Marek Szyprowski --- arch/arm/mm/dma-mapping.c | 2 ++ arch/powerpc/kernel/dma-swiotlb.c | 1 + arch/powerpc/kernel/dma.c | 1 + include/linux/dma-mapping.h | 12 +++++++----- kernel/dma/direct.c | 14 ++++++++++++++ 5 files changed, 25 insertions(+), 5 deletions(-) diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index f1e2922e447c..3c8534904209 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -188,6 +188,7 @@ const struct dma_map_ops arm_dma_ops = { .unmap_page = arm_dma_unmap_page, .map_sg = arm_dma_map_sg, .unmap_sg = arm_dma_unmap_sg, + .map_resource = dma_direct_map_resource, .sync_single_for_cpu = arm_dma_sync_single_for_cpu, .sync_single_for_device = arm_dma_sync_single_for_device, .sync_sg_for_cpu = arm_dma_sync_sg_for_cpu, @@ -211,6 +212,7 @@ const struct dma_map_ops arm_coherent_dma_ops = { .get_sgtable = arm_dma_get_sgtable, .map_page = arm_coherent_dma_map_page, .map_sg = arm_dma_map_sg, + .map_resource = dma_direct_map_resource, .dma_supported = arm_dma_supported, }; EXPORT_SYMBOL(arm_coherent_dma_ops); diff --git a/arch/powerpc/kernel/dma-swiotlb.c b/arch/powerpc/kernel/dma-swiotlb.c index 7d5fc9751622..fbb2506a414e 100644 --- a/arch/powerpc/kernel/dma-swiotlb.c +++ b/arch/powerpc/kernel/dma-swiotlb.c @@ -55,6 +55,7 @@ const struct dma_map_ops powerpc_swiotlb_dma_ops = { .dma_supported = swiotlb_dma_supported, .map_page = dma_direct_map_page, .unmap_page = dma_direct_unmap_page, + .map_resource = dma_direct_map_resource, .sync_single_for_cpu = dma_direct_sync_single_for_cpu, .sync_single_for_device = dma_direct_sync_single_for_device, .sync_sg_for_cpu = dma_direct_sync_sg_for_cpu, diff --git a/arch/powerpc/kernel/dma.c b/arch/powerpc/kernel/dma.c index b1903ebb2e9c..258b9e8ebb99 100644 --- a/arch/powerpc/kernel/dma.c +++ b/arch/powerpc/kernel/dma.c @@ -273,6 +273,7 @@ const struct dma_map_ops dma_nommu_ops = { .dma_supported = dma_nommu_dma_supported, .map_page = dma_nommu_map_page, .unmap_page = dma_nommu_unmap_page, + .map_resource = dma_direct_map_resource, .get_required_mask = dma_nommu_get_required_mask, #ifdef CONFIG_NOT_COHERENT_CACHE .sync_single_for_cpu = dma_nommu_sync_single, diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index f6ded992c183..9842085e6774 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -208,6 +208,8 @@ dma_addr_t dma_direct_map_page(struct device *dev, struct page *page, unsigned long attrs); int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, int nents, enum dma_data_direction dir, unsigned long attrs); +dma_addr_t dma_direct_map_resource(struct device *dev, phys_addr_t paddr, + size_t size, enum dma_data_direction dir, unsigned long attrs); #if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE) || \ defined(CONFIG_SWIOTLB) @@ -346,19 +348,19 @@ static inline dma_addr_t dma_map_resource(struct device *dev, unsigned long attrs) { const struct dma_map_ops *ops = get_dma_ops(dev); - dma_addr_t addr; + dma_addr_t addr = DMA_MAPPING_ERROR; BUG_ON(!valid_dma_direction(dir)); /* Don't allow RAM to be mapped */ BUG_ON(pfn_valid(PHYS_PFN(phys_addr))); - addr = phys_addr; - if (ops && ops->map_resource) + if (dma_is_direct(ops)) + addr = dma_direct_map_resource(dev, phys_addr, size, dir, attrs); + else if (ops->map_resource) addr = ops->map_resource(dev, phys_addr, size, dir, attrs); debug_dma_map_resource(dev, phys_addr, size, dir, addr); - return addr; } @@ -369,7 +371,7 @@ static inline void dma_unmap_resource(struct device *dev, dma_addr_t addr, const struct dma_map_ops *ops = get_dma_ops(dev); BUG_ON(!valid_dma_direction(dir)); - if (ops && ops->unmap_resource) + if (!dma_is_direct(ops) && ops->unmap_resource) ops->unmap_resource(dev, addr, size, dir, attrs); debug_dma_unmap_resource(dev, addr, size, dir); } diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c index 355d16acee6d..25bd19974223 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -356,6 +356,20 @@ out_unmap: } EXPORT_SYMBOL(dma_direct_map_sg); +dma_addr_t dma_direct_map_resource(struct device *dev, phys_addr_t paddr, + size_t size, enum dma_data_direction dir, unsigned long attrs) +{ + dma_addr_t dma_addr = paddr; + + if (unlikely(!dma_direct_possible(dev, dma_addr, size))) { + report_addr(dev, dma_addr, size); + return DMA_MAPPING_ERROR; + } + + return dma_addr; +} +EXPORT_SYMBOL(dma_direct_map_resource); + /* * Because 32-bit DMA masks are so common we expect every architecture to be * able to satisfy them - either by not supporting more physical memory, or by From 645386dfe6307dbb28f10a4513792a59beda0efa Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 4 Jan 2019 17:17:53 +0100 Subject: [PATCH 02/21] dma-mapping: don't BUG when calling dma_map_resource on RAM Use WARN_ON_ONCE to print a stack trace and return a proper error code instead. Signed-off-by: Christoph Hellwig Reviewed-by: Robin Murphy Tested-by: Marek Szyprowski --- include/linux/dma-mapping.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index 9842085e6774..b904d55247ab 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -353,7 +353,8 @@ static inline dma_addr_t dma_map_resource(struct device *dev, BUG_ON(!valid_dma_direction(dir)); /* Don't allow RAM to be mapped */ - BUG_ON(pfn_valid(PHYS_PFN(phys_addr))); + if (WARN_ON_ONCE(pfn_valid(PHYS_PFN(phys_addr)))) + return DMA_MAPPING_ERROR; if (dma_is_direct(ops)) addr = dma_direct_map_resource(dev, phys_addr, size, dir, attrs); From 55ea54441fb3b6532d5d32417911ff5a10750903 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 4 Jan 2019 10:42:49 +0100 Subject: [PATCH 03/21] videobuf2: replace a layering violation with dma_map_resource vb2_dc_get_userptr pokes into arm direct mapping details to get the resemblance of a dma address for a a physical address that does is not backed by a page struct. Not only is this not portable to other architectures with dma direct mapping offsets, but also not to uses of IOMMUs of any kind. Switch to the proper dma_map_resource / dma_unmap_resource interface instead. Signed-off-by: Christoph Hellwig Acked-by: Mauro Carvalho Chehab Tested-by: Marek Szyprowski --- .../common/videobuf2/videobuf2-dma-contig.c | 41 ++++--------------- 1 file changed, 9 insertions(+), 32 deletions(-) diff --git a/drivers/media/common/videobuf2/videobuf2-dma-contig.c b/drivers/media/common/videobuf2/videobuf2-dma-contig.c index aff0ab7bf83d..82389aead6ed 100644 --- a/drivers/media/common/videobuf2/videobuf2-dma-contig.c +++ b/drivers/media/common/videobuf2/videobuf2-dma-contig.c @@ -439,42 +439,14 @@ static void vb2_dc_put_userptr(void *buf_priv) set_page_dirty_lock(pages[i]); sg_free_table(sgt); kfree(sgt); + } else { + dma_unmap_resource(buf->dev, buf->dma_addr, buf->size, + buf->dma_dir, 0); } vb2_destroy_framevec(buf->vec); kfree(buf); } -/* - * For some kind of reserved memory there might be no struct page available, - * so all that can be done to support such 'pages' is to try to convert - * pfn to dma address or at the last resort just assume that - * dma address == physical address (like it has been assumed in earlier version - * of videobuf2-dma-contig - */ - -#ifdef __arch_pfn_to_dma -static inline dma_addr_t vb2_dc_pfn_to_dma(struct device *dev, unsigned long pfn) -{ - return (dma_addr_t)__arch_pfn_to_dma(dev, pfn); -} -#elif defined(__pfn_to_bus) -static inline dma_addr_t vb2_dc_pfn_to_dma(struct device *dev, unsigned long pfn) -{ - return (dma_addr_t)__pfn_to_bus(pfn); -} -#elif defined(__pfn_to_phys) -static inline dma_addr_t vb2_dc_pfn_to_dma(struct device *dev, unsigned long pfn) -{ - return (dma_addr_t)__pfn_to_phys(pfn); -} -#else -static inline dma_addr_t vb2_dc_pfn_to_dma(struct device *dev, unsigned long pfn) -{ - /* really, we cannot do anything better at this point */ - return (dma_addr_t)(pfn) << PAGE_SHIFT; -} -#endif - static void *vb2_dc_get_userptr(struct device *dev, unsigned long vaddr, unsigned long size, enum dma_data_direction dma_dir) { @@ -528,7 +500,12 @@ static void *vb2_dc_get_userptr(struct device *dev, unsigned long vaddr, for (i = 1; i < n_pages; i++) if (nums[i-1] + 1 != nums[i]) goto fail_pfnvec; - buf->dma_addr = vb2_dc_pfn_to_dma(buf->dev, nums[0]); + buf->dma_addr = dma_map_resource(buf->dev, + __pfn_to_phys(nums[0]), size, buf->dma_dir, 0); + if (dma_mapping_error(buf->dev, buf->dma_addr)) { + ret = -ENOMEM; + goto fail_pfnvec; + } goto out; } From 8e4d81b98b7859b120dd142c8634f625db118b30 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Tue, 22 Jan 2019 16:21:38 +0100 Subject: [PATCH 04/21] dma: debug: no need to check return value of debugfs_create functions When calling debugfs functions, there is no need to ever check the return value. The function can work or not, but the code logic should never do something different based on this. Also delete the variables for the file dentries for the debugfs entries as they are never used at all once they are created. Signed-off-by: Greg Kroah-Hartman Reviewed-by: Robin Murphy [hch: moved dma_debug_dent to function scope and renamed it] Signed-off-by: Christoph Hellwig --- kernel/dma/debug.c | 86 ++++++---------------------------------------- 1 file changed, 11 insertions(+), 75 deletions(-) diff --git a/kernel/dma/debug.c b/kernel/dma/debug.c index 23cf5361bcf1..56cd836a902c 100644 --- a/kernel/dma/debug.c +++ b/kernel/dma/debug.c @@ -134,17 +134,6 @@ static u32 nr_total_entries; /* number of preallocated entries requested by kernel cmdline */ static u32 nr_prealloc_entries = PREALLOC_DMA_DEBUG_ENTRIES; -/* debugfs dentry's for the stuff above */ -static struct dentry *dma_debug_dent __read_mostly; -static struct dentry *global_disable_dent __read_mostly; -static struct dentry *error_count_dent __read_mostly; -static struct dentry *show_all_errors_dent __read_mostly; -static struct dentry *show_num_errors_dent __read_mostly; -static struct dentry *num_free_entries_dent __read_mostly; -static struct dentry *min_free_entries_dent __read_mostly; -static struct dentry *nr_total_entries_dent __read_mostly; -static struct dentry *filter_dent __read_mostly; - /* per-driver filter related state */ #define NAME_MAX_LEN 64 @@ -840,66 +829,18 @@ static const struct file_operations filter_fops = { .llseek = default_llseek, }; -static int dma_debug_fs_init(void) +static void dma_debug_fs_init(void) { - dma_debug_dent = debugfs_create_dir("dma-api", NULL); - if (!dma_debug_dent) { - pr_err("can not create debugfs directory\n"); - return -ENOMEM; - } + struct dentry *dentry = debugfs_create_dir("dma-api", NULL); - global_disable_dent = debugfs_create_bool("disabled", 0444, - dma_debug_dent, - &global_disable); - if (!global_disable_dent) - goto out_err; - - error_count_dent = debugfs_create_u32("error_count", 0444, - dma_debug_dent, &error_count); - if (!error_count_dent) - goto out_err; - - show_all_errors_dent = debugfs_create_u32("all_errors", 0644, - dma_debug_dent, - &show_all_errors); - if (!show_all_errors_dent) - goto out_err; - - show_num_errors_dent = debugfs_create_u32("num_errors", 0644, - dma_debug_dent, - &show_num_errors); - if (!show_num_errors_dent) - goto out_err; - - num_free_entries_dent = debugfs_create_u32("num_free_entries", 0444, - dma_debug_dent, - &num_free_entries); - if (!num_free_entries_dent) - goto out_err; - - min_free_entries_dent = debugfs_create_u32("min_free_entries", 0444, - dma_debug_dent, - &min_free_entries); - if (!min_free_entries_dent) - goto out_err; - - nr_total_entries_dent = debugfs_create_u32("nr_total_entries", 0444, - dma_debug_dent, - &nr_total_entries); - if (!nr_total_entries_dent) - goto out_err; - - filter_dent = debugfs_create_file("driver_filter", 0644, - dma_debug_dent, NULL, &filter_fops); - if (!filter_dent) - goto out_err; - - return 0; - -out_err: - debugfs_remove_recursive(dma_debug_dent); - - return -ENOMEM; + debugfs_create_bool("disabled", 0444, dentry, &global_disable); + debugfs_create_u32("error_count", 0444, dentry, &error_count); + debugfs_create_u32("all_errors", 0644, dentry, &show_all_errors); + debugfs_create_u32("num_errors", 0644, dentry, &show_num_errors); + debugfs_create_u32("num_free_entries", 0444, dentry, &num_free_entries); + debugfs_create_u32("min_free_entries", 0444, dentry, &min_free_entries); + debugfs_create_u32("nr_total_entries", 0444, dentry, &nr_total_entries); + debugfs_create_file("driver_filter", 0644, dentry, NULL, &filter_fops); } static int device_dma_allocations(struct device *dev, struct dma_debug_entry **out_entry) @@ -985,12 +926,7 @@ static int dma_debug_init(void) spin_lock_init(&dma_entry_hash[i].lock); } - if (dma_debug_fs_init() != 0) { - pr_err("error creating debugfs entries - disabling\n"); - global_disable = true; - - return 0; - } + dma_debug_fs_init(); nr_pages = DIV_ROUND_UP(nr_prealloc_entries, DMA_DEBUG_DYNAMIC_ENTRIES); for (i = 0; i < nr_pages; ++i) From 0a3b192c26da198fce38e1ee242a34f558670246 Mon Sep 17 00:00:00 2001 From: Corentin Labbe Date: Fri, 18 Jan 2019 13:44:18 +0000 Subject: [PATCH 05/21] dma-debug: add dumping facility via debugfs While debugging a DMA mapping leak, I needed to access debug_dma_dump_mappings() but easily from user space. This patch adds a /sys/kernel/debug/dma-api/dump file which contain all current DMA mapping. Signed-off-by: Corentin Labbe Signed-off-by: Christoph Hellwig --- Documentation/DMA-API.txt | 3 +++ kernel/dma/debug.c | 28 ++++++++++++++++++++++++++++ 2 files changed, 31 insertions(+) diff --git a/Documentation/DMA-API.txt b/Documentation/DMA-API.txt index e133ccd60228..78114ee63057 100644 --- a/Documentation/DMA-API.txt +++ b/Documentation/DMA-API.txt @@ -696,6 +696,9 @@ dma-api/disabled This read-only file contains the character 'Y' happen when it runs out of memory or if it was disabled at boot time +dma-api/dump This read-only file contains current DMA + mappings. + dma-api/error_count This file is read-only and shows the total numbers of errors found. diff --git a/kernel/dma/debug.c b/kernel/dma/debug.c index 56cd836a902c..45d51e8e26f6 100644 --- a/kernel/dma/debug.c +++ b/kernel/dma/debug.c @@ -829,6 +829,33 @@ static const struct file_operations filter_fops = { .llseek = default_llseek, }; +static int dump_show(struct seq_file *seq, void *v) +{ + int idx; + + for (idx = 0; idx < HASH_SIZE; idx++) { + struct hash_bucket *bucket = &dma_entry_hash[idx]; + struct dma_debug_entry *entry; + unsigned long flags; + + spin_lock_irqsave(&bucket->lock, flags); + list_for_each_entry(entry, &bucket->list, list) { + seq_printf(seq, + "%s %s %s idx %d P=%llx N=%lx D=%llx L=%llx %s %s\n", + dev_name(entry->dev), + dev_driver_string(entry->dev), + type2name[entry->type], idx, + phys_addr(entry), entry->pfn, + entry->dev_addr, entry->size, + dir2name[entry->direction], + maperr2str[entry->map_err_type]); + } + spin_unlock_irqrestore(&bucket->lock, flags); + } + return 0; +} +DEFINE_SHOW_ATTRIBUTE(dump); + static void dma_debug_fs_init(void) { struct dentry *dentry = debugfs_create_dir("dma-api", NULL); @@ -841,6 +868,7 @@ static void dma_debug_fs_init(void) debugfs_create_u32("min_free_entries", 0444, dentry, &min_free_entries); debugfs_create_u32("nr_total_entries", 0444, dentry, &nr_total_entries); debugfs_create_file("driver_filter", 0644, dentry, NULL, &filter_fops); + debugfs_create_file("dump", 0444, dentry, NULL, &dump_fops); } static int device_dma_allocations(struct device *dev, struct dma_debug_entry **out_entry) From 70ca7ba2dbe4f1858b85e30269c8408a8bb8f272 Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Mon, 11 Feb 2019 18:12:30 +0200 Subject: [PATCH 06/21] dma-mapping: move debug configuration options to kernel/dma This is a follow up to the commit cf65a0f6f6ff ("dma-mapping: move all DMA mapping code to kernel/dma") which moved source code of DMA API to kernel/dma folder. Since there is no file left in the lib that require DMA API debugging options move the latter to kernel/dma as well. Cc: Christoph Hellwig Signed-off-by: Andy Shevchenko Signed-off-by: Christoph Hellwig --- kernel/dma/Kconfig | 36 ++++++++++++++++++++++++++++++++++++ lib/Kconfig.debug | 36 ------------------------------------ 2 files changed, 36 insertions(+), 36 deletions(-) diff --git a/kernel/dma/Kconfig b/kernel/dma/Kconfig index ca88b867e7fe..61cebea36d89 100644 --- a/kernel/dma/Kconfig +++ b/kernel/dma/Kconfig @@ -53,3 +53,39 @@ config DMA_REMAP config DMA_DIRECT_REMAP bool select DMA_REMAP + +config DMA_API_DEBUG + bool "Enable debugging of DMA-API usage" + select NEED_DMA_MAP_STATE + help + Enable this option to debug the use of the DMA API by device drivers. + With this option you will be able to detect common bugs in device + drivers like double-freeing of DMA mappings or freeing mappings that + were never allocated. + + This also attempts to catch cases where a page owned by DMA is + accessed by the cpu in a way that could cause data corruption. For + example, this enables cow_user_page() to check that the source page is + not undergoing DMA. + + This option causes a performance degradation. Use only if you want to + debug device drivers and dma interactions. + + If unsure, say N. + +config DMA_API_DEBUG_SG + bool "Debug DMA scatter-gather usage" + default y + depends on DMA_API_DEBUG + help + Perform extra checking that callers of dma_map_sg() have respected the + appropriate segment length/boundary limits for the given device when + preparing DMA scatterlists. + + This is particularly likely to have been overlooked in cases where the + dma_map_sg() API is used for general bulk mapping of pages rather than + preparing literal scatter-gather descriptors, where there is a risk of + unexpected behaviour from DMA API implementations if the scatterlist + is technically out-of-spec. + + If unsure, say N. diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index d4df5b24d75e..ef5d7c08e5b9 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1655,42 +1655,6 @@ config PROVIDE_OHCI1394_DMA_INIT See Documentation/debugging-via-ohci1394.txt for more information. -config DMA_API_DEBUG - bool "Enable debugging of DMA-API usage" - select NEED_DMA_MAP_STATE - help - Enable this option to debug the use of the DMA API by device drivers. - With this option you will be able to detect common bugs in device - drivers like double-freeing of DMA mappings or freeing mappings that - were never allocated. - - This also attempts to catch cases where a page owned by DMA is - accessed by the cpu in a way that could cause data corruption. For - example, this enables cow_user_page() to check that the source page is - not undergoing DMA. - - This option causes a performance degradation. Use only if you want to - debug device drivers and dma interactions. - - If unsure, say N. - -config DMA_API_DEBUG_SG - bool "Debug DMA scatter-gather usage" - default y - depends on DMA_API_DEBUG - help - Perform extra checking that callers of dma_map_sg() have respected the - appropriate segment length/boundary limits for the given device when - preparing DMA scatterlists. - - This is particularly likely to have been overlooked in cases where the - dma_map_sg() API is used for general bulk mapping of pages rather than - preparing literal scatter-gather descriptors, where there is a risk of - unexpected behaviour from DMA API implementations if the scatterlist - is technically out-of-spec. - - If unsure, say N. - menuconfig RUNTIME_TESTING_MENU bool "Runtime Testing" def_bool y From 347cb6af8710b72cf9685fdc09d07873cf42d51f Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 7 Jan 2019 13:36:20 -0500 Subject: [PATCH 07/21] dma-mapping: add a kconfig symbol for arch_setup_dma_ops availability Signed-off-by: Christoph Hellwig Acked-by: Paul Burton # MIPS Acked-by: Catalin Marinas # arm64 --- arch/arc/Kconfig | 1 + arch/arc/include/asm/Kbuild | 1 + arch/arc/include/asm/dma-mapping.h | 13 ------------- arch/arm/Kconfig | 1 + arch/arm/include/asm/dma-mapping.h | 4 ---- arch/arm64/Kconfig | 1 + arch/arm64/include/asm/dma-mapping.h | 4 ---- arch/mips/Kconfig | 1 + arch/mips/include/asm/dma-mapping.h | 10 ---------- arch/mips/mm/dma-noncoherent.c | 8 ++++++++ include/linux/dma-mapping.h | 12 ++++++++---- kernel/dma/Kconfig | 3 +++ 12 files changed, 24 insertions(+), 35 deletions(-) delete mode 100644 arch/arc/include/asm/dma-mapping.h diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig index 376366a7db81..2ab27d88eb1c 100644 --- a/arch/arc/Kconfig +++ b/arch/arc/Kconfig @@ -11,6 +11,7 @@ config ARC select ARC_TIMERS select ARCH_HAS_DMA_COHERENT_TO_PFN select ARCH_HAS_PTE_SPECIAL + select ARCH_HAS_SETUP_DMA_OPS select ARCH_HAS_SYNC_DMA_FOR_CPU select ARCH_HAS_SYNC_DMA_FOR_DEVICE select ARCH_SUPPORTS_ATOMIC_RMW if ARC_HAS_LLSC diff --git a/arch/arc/include/asm/Kbuild b/arch/arc/include/asm/Kbuild index caa270261521..b41f8881ecc8 100644 --- a/arch/arc/include/asm/Kbuild +++ b/arch/arc/include/asm/Kbuild @@ -3,6 +3,7 @@ generic-y += bugs.h generic-y += compat.h generic-y += device.h generic-y += div64.h +generic-y += dma-mapping.h generic-y += emergency-restart.h generic-y += extable.h generic-y += ftrace.h diff --git a/arch/arc/include/asm/dma-mapping.h b/arch/arc/include/asm/dma-mapping.h deleted file mode 100644 index c946c0a83e76..000000000000 --- a/arch/arc/include/asm/dma-mapping.h +++ /dev/null @@ -1,13 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -// (C) 2018 Synopsys, Inc. (www.synopsys.com) - -#ifndef ASM_ARC_DMA_MAPPING_H -#define ASM_ARC_DMA_MAPPING_H - -#include - -void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size, - const struct iommu_ops *iommu, bool coherent); -#define arch_setup_dma_ops arch_setup_dma_ops - -#endif diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 664e918e2624..c1cf44f00870 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -12,6 +12,7 @@ config ARM select ARCH_HAS_MEMBARRIER_SYNC_CORE select ARCH_HAS_PTE_SPECIAL if ARM_LPAE select ARCH_HAS_PHYS_TO_DMA + select ARCH_HAS_SETUP_DMA_OPS select ARCH_HAS_SET_MEMORY select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL select ARCH_HAS_STRICT_MODULE_RWX if MMU diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h index 31d3b96f0f4b..a224b6e39e58 100644 --- a/arch/arm/include/asm/dma-mapping.h +++ b/arch/arm/include/asm/dma-mapping.h @@ -96,10 +96,6 @@ static inline unsigned long dma_max_pfn(struct device *dev) } #define dma_max_pfn(dev) dma_max_pfn(dev) -#define arch_setup_dma_ops arch_setup_dma_ops -extern void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size, - const struct iommu_ops *iommu, bool coherent); - #ifdef CONFIG_MMU #define arch_teardown_dma_ops arch_teardown_dma_ops extern void arch_teardown_dma_ops(struct device *dev); diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index a4168d366127..63909f318d56 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -22,6 +22,7 @@ config ARM64 select ARCH_HAS_KCOV select ARCH_HAS_MEMBARRIER_SYNC_CORE select ARCH_HAS_PTE_SPECIAL + select ARCH_HAS_SETUP_DMA_OPS select ARCH_HAS_SET_MEMORY select ARCH_HAS_STRICT_KERNEL_RWX select ARCH_HAS_STRICT_MODULE_RWX diff --git a/arch/arm64/include/asm/dma-mapping.h b/arch/arm64/include/asm/dma-mapping.h index 95dbf3ef735a..de96507ee2c1 100644 --- a/arch/arm64/include/asm/dma-mapping.h +++ b/arch/arm64/include/asm/dma-mapping.h @@ -29,10 +29,6 @@ static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus) return NULL; } -void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size, - const struct iommu_ops *iommu, bool coherent); -#define arch_setup_dma_ops arch_setup_dma_ops - #ifdef CONFIG_IOMMU_DMA void arch_teardown_dma_ops(struct device *dev); #define arch_teardown_dma_ops arch_teardown_dma_ops diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig index 0d14f51d0002..dc5d70f674e0 100644 --- a/arch/mips/Kconfig +++ b/arch/mips/Kconfig @@ -1118,6 +1118,7 @@ config DMA_MAYBE_COHERENT config DMA_PERDEV_COHERENT bool + select ARCH_HAS_SETUP_DMA_OPS select DMA_NONCOHERENT config DMA_NONCOHERENT diff --git a/arch/mips/include/asm/dma-mapping.h b/arch/mips/include/asm/dma-mapping.h index 20dfaad3a55d..34de7b17b41b 100644 --- a/arch/mips/include/asm/dma-mapping.h +++ b/arch/mips/include/asm/dma-mapping.h @@ -15,14 +15,4 @@ static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus) #endif } -#define arch_setup_dma_ops arch_setup_dma_ops -static inline void arch_setup_dma_ops(struct device *dev, u64 dma_base, - u64 size, const struct iommu_ops *iommu, - bool coherent) -{ -#ifdef CONFIG_DMA_PERDEV_COHERENT - dev->dma_coherent = coherent; -#endif -} - #endif /* _ASM_DMA_MAPPING_H */ diff --git a/arch/mips/mm/dma-noncoherent.c b/arch/mips/mm/dma-noncoherent.c index cb38461391cb..0606fc87b294 100644 --- a/arch/mips/mm/dma-noncoherent.c +++ b/arch/mips/mm/dma-noncoherent.c @@ -159,3 +159,11 @@ void arch_dma_cache_sync(struct device *dev, void *vaddr, size_t size, dma_sync_virt(vaddr, size, direction); } + +#ifdef CONFIG_DMA_PERDEV_COHERENT +void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size, + const struct iommu_ops *iommu, bool coherent) +{ + dev->dma_coherent = coherent; +} +#endif diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index b904d55247ab..2b20d60e6158 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -671,11 +671,15 @@ static inline int dma_coerce_mask_and_coherent(struct device *dev, u64 mask) return dma_set_mask_and_coherent(dev, mask); } -#ifndef arch_setup_dma_ops +#ifdef CONFIG_ARCH_HAS_SETUP_DMA_OPS +void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size, + const struct iommu_ops *iommu, bool coherent); +#else static inline void arch_setup_dma_ops(struct device *dev, u64 dma_base, - u64 size, const struct iommu_ops *iommu, - bool coherent) { } -#endif + u64 size, const struct iommu_ops *iommu, bool coherent) +{ +} +#endif /* CONFIG_ARCH_HAS_SETUP_DMA_OPS */ #ifndef arch_teardown_dma_ops static inline void arch_teardown_dma_ops(struct device *dev) { } diff --git a/kernel/dma/Kconfig b/kernel/dma/Kconfig index 61cebea36d89..6014cad35e58 100644 --- a/kernel/dma/Kconfig +++ b/kernel/dma/Kconfig @@ -19,6 +19,9 @@ config ARCH_HAS_DMA_COHERENCE_H config HAVE_GENERIC_DMA_COHERENT bool +config ARCH_HAS_SETUP_DMA_OPS + bool + config ARCH_HAS_SYNC_DMA_FOR_DEVICE bool From dc2acded38957dfa6b7b7e0203b4b8cb8d818ce6 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 21 Dec 2018 22:14:44 +0100 Subject: [PATCH 08/21] dma-mapping: add a kconfig symbol for arch_teardown_dma_ops availability Signed-off-by: Christoph Hellwig Acked-by: Catalin Marinas # arm64 --- arch/arm/Kconfig | 1 + arch/arm/include/asm/dma-mapping.h | 5 ----- arch/arm64/Kconfig | 1 + arch/arm64/include/asm/dma-mapping.h | 5 ----- include/linux/dma-mapping.h | 10 +++++++--- kernel/dma/Kconfig | 3 +++ 6 files changed, 12 insertions(+), 13 deletions(-) diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index c1cf44f00870..4bb36ae71b14 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -16,6 +16,7 @@ config ARM select ARCH_HAS_SET_MEMORY select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL select ARCH_HAS_STRICT_MODULE_RWX if MMU + select ARCH_HAS_TEARDOWN_DMA_OPS if MMU select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST select ARCH_HAVE_CUSTOM_GPIO_H select ARCH_HAS_GCOV_PROFILE_ALL diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h index a224b6e39e58..03ba90ffc0f8 100644 --- a/arch/arm/include/asm/dma-mapping.h +++ b/arch/arm/include/asm/dma-mapping.h @@ -96,11 +96,6 @@ static inline unsigned long dma_max_pfn(struct device *dev) } #define dma_max_pfn(dev) dma_max_pfn(dev) -#ifdef CONFIG_MMU -#define arch_teardown_dma_ops arch_teardown_dma_ops -extern void arch_teardown_dma_ops(struct device *dev); -#endif - /* do not use this function in a driver */ static inline bool is_device_dma_coherent(struct device *dev) { diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 63909f318d56..87ec7be25e97 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -29,6 +29,7 @@ config ARM64 select ARCH_HAS_SYNC_DMA_FOR_DEVICE select ARCH_HAS_SYNC_DMA_FOR_CPU select ARCH_HAS_SYSCALL_WRAPPER + select ARCH_HAS_TEARDOWN_DMA_OPS if IOMMU_SUPPORT select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST select ARCH_HAVE_NMI_SAFE_CMPXCHG select ARCH_INLINE_READ_LOCK if !PREEMPT diff --git a/arch/arm64/include/asm/dma-mapping.h b/arch/arm64/include/asm/dma-mapping.h index de96507ee2c1..de98191e4c7d 100644 --- a/arch/arm64/include/asm/dma-mapping.h +++ b/arch/arm64/include/asm/dma-mapping.h @@ -29,11 +29,6 @@ static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus) return NULL; } -#ifdef CONFIG_IOMMU_DMA -void arch_teardown_dma_ops(struct device *dev); -#define arch_teardown_dma_ops arch_teardown_dma_ops -#endif - /* * Do not use this function in a driver, it is only provided for * arch/arm/mm/xen.c, which is used by arm64 as well. diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index 2b20d60e6158..4210c5c1dd21 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -681,9 +681,13 @@ static inline void arch_setup_dma_ops(struct device *dev, u64 dma_base, } #endif /* CONFIG_ARCH_HAS_SETUP_DMA_OPS */ -#ifndef arch_teardown_dma_ops -static inline void arch_teardown_dma_ops(struct device *dev) { } -#endif +#ifdef CONFIG_ARCH_HAS_TEARDOWN_DMA_OPS +void arch_teardown_dma_ops(struct device *dev); +#else +static inline void arch_teardown_dma_ops(struct device *dev) +{ +} +#endif /* CONFIG_ARCH_HAS_TEARDOWN_DMA_OPS */ static inline unsigned int dma_get_max_seg_size(struct device *dev) { diff --git a/kernel/dma/Kconfig b/kernel/dma/Kconfig index 6014cad35e58..bde9179c6ed7 100644 --- a/kernel/dma/Kconfig +++ b/kernel/dma/Kconfig @@ -22,6 +22,9 @@ config HAVE_GENERIC_DMA_COHERENT config ARCH_HAS_SETUP_DMA_OPS bool +config ARCH_HAS_TEARDOWN_DMA_OPS + bool + config ARCH_HAS_SYNC_DMA_FOR_DEVICE bool From d0377392201b4cab670dafd092b17164f49d8b8e Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Sun, 3 Feb 2019 20:11:53 +0100 Subject: [PATCH 09/21] mfd/sm501: depend on HAS_DMA Currently the sm501 mfd driver can be compiled without any dependencies, but through the use of dma_declare_coherent it really depends on having DMA and iomem support. Normally we don't explicitly require DMA support as we have stubs for it if on UML, but in this case the driver selects support for dma_declare_coherent and thus also requires memmap support. Guard this by an explicit dependency. Signed-off-by: Christoph Hellwig Acked-by: Lee Jones --- drivers/mfd/Kconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig index f461460a2aeb..f15f6489803d 100644 --- a/drivers/mfd/Kconfig +++ b/drivers/mfd/Kconfig @@ -1066,6 +1066,7 @@ config MFD_SI476X_CORE config MFD_SM501 tristate "Silicon Motion SM501" + depends on HAS_DMA ---help--- This is the core driver for the Silicon Motion SM501 multimedia companion chip. This device is a multifunction device which may From 2b2812961302c38500c1027778e371c895f1cac4 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 25 Dec 2018 14:03:32 +0100 Subject: [PATCH 10/21] device.h: dma_mem is only needed for HAVE_GENERIC_DMA_COHERENT No need to carry an unused field around. Signed-off-by: Christoph Hellwig Reviewed-by: Greg Kroah-Hartman --- include/linux/device.h | 2 ++ 1 file changed, 2 insertions(+) diff --git a/include/linux/device.h b/include/linux/device.h index 6cb4640b6160..be544400acdd 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -1017,8 +1017,10 @@ struct device { struct list_head dma_pools; /* dma pools (if dma'ble) */ +#ifdef CONFIG_HAVE_GENERIC_DMA_COHERENT struct dma_coherent_mem *dma_mem; /* internal for coherent mem override */ +#endif #ifdef CONFIG_DMA_CMA struct cma *cma_area; /* contiguous memory area for dma allocations */ From 34e04eedd1cf1be714abb0e5976338cc72ccc05f Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 1 Feb 2019 10:10:52 +0100 Subject: [PATCH 11/21] of: select OF_RESERVED_MEM automatically The OF_RESERVED_MEM can be used if we have either CMA or the generic declare coherent code built and we support the early flattened DT. So don't bother making it a user visible options that is selected by most configs that fit the above category, but just select it when the requirements are met. Signed-off-by: Christoph Hellwig Reviewed-by: Rob Herring --- arch/arc/Kconfig | 1 - arch/arm/Kconfig | 1 - arch/arm64/Kconfig | 1 - arch/csky/Kconfig | 1 - arch/powerpc/Kconfig | 1 - arch/xtensa/Kconfig | 1 - drivers/of/Kconfig | 5 ++--- 7 files changed, 2 insertions(+), 9 deletions(-) diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig index 2ab27d88eb1c..ab8d6131c954 100644 --- a/arch/arc/Kconfig +++ b/arch/arc/Kconfig @@ -45,7 +45,6 @@ config ARC select MODULES_USE_ELF_RELA select OF select OF_EARLY_FLATTREE - select OF_RESERVED_MEM select PCI_SYSCALL if PCI select PERF_USE_VMALLOC if ARC_CACHE_VIPT_ALIASING diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 4bb36ae71b14..e07e5c184d2f 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -103,7 +103,6 @@ config ARM select MODULES_USE_ELF_REL select NEED_DMA_MAP_STATE select OF_EARLY_FLATTREE if OF - select OF_RESERVED_MEM if OF select OLD_SIGACTION select OLD_SIGSUSPEND3 select PCI_SYSCALL if PCI diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 87ec7be25e97..fbcf521e1c9f 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -165,7 +165,6 @@ config ARM64 select NEED_SG_DMA_LENGTH select OF select OF_EARLY_FLATTREE - select OF_RESERVED_MEM select PCI_DOMAINS_GENERIC if PCI select PCI_ECAM if (ACPI && PCI) select PCI_SYSCALL if PCI diff --git a/arch/csky/Kconfig b/arch/csky/Kconfig index 398113c845f5..0a9595afe9be 100644 --- a/arch/csky/Kconfig +++ b/arch/csky/Kconfig @@ -42,7 +42,6 @@ config CSKY select MODULES_USE_ELF_RELA if MODULES select OF select OF_EARLY_FLATTREE - select OF_RESERVED_MEM select PERF_USE_VMALLOC if CPU_CK610 select RTC_LIB select TIMER_OF diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 2890d36eb531..5cc4eea362c6 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -233,7 +233,6 @@ config PPC select NEED_SG_DMA_LENGTH select OF select OF_EARLY_FLATTREE - select OF_RESERVED_MEM select OLD_SIGACTION if PPC32 select OLD_SIGSUSPEND select PCI_DOMAINS if PCI diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig index 20a0756f27ef..e242a405151e 100644 --- a/arch/xtensa/Kconfig +++ b/arch/xtensa/Kconfig @@ -447,7 +447,6 @@ config USE_OF bool "Flattened Device Tree support" select OF select OF_EARLY_FLATTREE - select OF_RESERVED_MEM help Include support for flattened device tree machine descriptions. diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig index ad3fcad4d75b..3607fd2810e4 100644 --- a/drivers/of/Kconfig +++ b/drivers/of/Kconfig @@ -81,10 +81,9 @@ config OF_MDIO OpenFirmware MDIO bus (Ethernet PHY) accessors config OF_RESERVED_MEM - depends on OF_EARLY_FLATTREE bool - help - Helpers to allow for reservation of memory regions + depends on OF_EARLY_FLATTREE + default y if HAVE_GENERIC_DMA_COHERENT || DMA_CMA config OF_RESOLVE bool From be4311a262bcf29da60c1ef6b5a457fe5d9cccef Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 1 Feb 2019 22:25:09 +0100 Subject: [PATCH 12/21] dma-mapping: remove an incorrect __iommem annotation memmap return a regular void pointer, not and __iomem one. Signed-off-by: Christoph Hellwig --- kernel/dma/coherent.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/dma/coherent.c b/kernel/dma/coherent.c index 66f0fb7e9a3a..4b76aba574c2 100644 --- a/kernel/dma/coherent.c +++ b/kernel/dma/coherent.c @@ -43,7 +43,7 @@ static int dma_init_coherent_memory( struct dma_coherent_mem **mem) { struct dma_coherent_mem *dma_mem = NULL; - void __iomem *mem_base = NULL; + void *mem_base = NULL; int pages = size >> PAGE_SHIFT; int bitmap_size = BITS_TO_LONGS(pages) * sizeof(long); int ret; From ff4c25f26a71b79c70ea03b3935a1297439a8a85 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Sun, 3 Feb 2019 20:12:02 +0100 Subject: [PATCH 13/21] dma-mapping: improve selection of dma_declare_coherent availability This API is primarily used through DT entries, but two architectures and two drivers call it directly. So instead of selecting the config symbol for random architectures pull it in implicitly for the actual users. Also rename the Kconfig option to describe the feature better. Signed-off-by: Christoph Hellwig Acked-by: Paul Burton # MIPS Acked-by: Lee Jones Reviewed-by: Greg Kroah-Hartman --- arch/arc/Kconfig | 1 - arch/arm/Kconfig | 2 +- arch/arm64/Kconfig | 1 - arch/csky/Kconfig | 1 - arch/mips/Kconfig | 1 - arch/riscv/Kconfig | 1 - arch/sh/Kconfig | 2 +- arch/unicore32/Kconfig | 1 - arch/x86/Kconfig | 1 - drivers/mfd/Kconfig | 2 ++ drivers/of/Kconfig | 3 ++- include/linux/device.h | 2 +- include/linux/dma-mapping.h | 8 ++++---- kernel/dma/Kconfig | 2 +- kernel/dma/Makefile | 2 +- 15 files changed, 13 insertions(+), 17 deletions(-) diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig index ab8d6131c954..728a0f6f838c 100644 --- a/arch/arc/Kconfig +++ b/arch/arc/Kconfig @@ -31,7 +31,6 @@ config ARC select HAVE_ARCH_TRACEHOOK select HAVE_DEBUG_STACKOVERFLOW select HAVE_FUTEX_CMPXCHG if FUTEX - select HAVE_GENERIC_DMA_COHERENT select HAVE_IOREMAP_PROT select HAVE_KERNEL_GZIP select HAVE_KERNEL_LZMA diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index e07e5c184d2f..33612e6da19a 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -32,6 +32,7 @@ config ARM select CLONE_BACKWARDS select CPU_PM if SUSPEND || CPU_IDLE select DCACHE_WORD_ACCESS if HAVE_EFFICIENT_UNALIGNED_ACCESS + select DMA_DECLARE_COHERENT select DMA_REMAP if MMU select EDAC_SUPPORT select EDAC_ATOMIC_SCRUB @@ -74,7 +75,6 @@ config ARM select HAVE_FUNCTION_GRAPH_TRACER if !THUMB2_KERNEL select HAVE_FUNCTION_TRACER if !XIP_KERNEL select HAVE_GCC_PLUGINS - select HAVE_GENERIC_DMA_COHERENT select HAVE_HW_BREAKPOINT if PERF_EVENTS && (CPU_V6 || CPU_V6K || CPU_V7) select HAVE_IDE if PCI || ISA || PCMCIA select HAVE_IRQ_TIME_ACCOUNTING diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index fbcf521e1c9f..e86fac1e6b03 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -139,7 +139,6 @@ config ARM64 select HAVE_FUNCTION_TRACER select HAVE_FUNCTION_GRAPH_TRACER select HAVE_GCC_PLUGINS - select HAVE_GENERIC_DMA_COHERENT select HAVE_HW_BREAKPOINT if PERF_EVENTS select HAVE_IRQ_TIME_ACCOUNTING select HAVE_MEMBLOCK_NODE_MAP if NUMA diff --git a/arch/csky/Kconfig b/arch/csky/Kconfig index 0a9595afe9be..c009a8c63946 100644 --- a/arch/csky/Kconfig +++ b/arch/csky/Kconfig @@ -30,7 +30,6 @@ config CSKY select HAVE_ARCH_TRACEHOOK select HAVE_FUNCTION_TRACER select HAVE_FUNCTION_GRAPH_TRACER - select HAVE_GENERIC_DMA_COHERENT select HAVE_KERNEL_GZIP select HAVE_KERNEL_LZO select HAVE_KERNEL_LZMA diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig index dc5d70f674e0..433b9dd35824 100644 --- a/arch/mips/Kconfig +++ b/arch/mips/Kconfig @@ -56,7 +56,6 @@ config MIPS select HAVE_FTRACE_MCOUNT_RECORD select HAVE_FUNCTION_GRAPH_TRACER select HAVE_FUNCTION_TRACER - select HAVE_GENERIC_DMA_COHERENT select HAVE_IDE select HAVE_IOREMAP_PROT select HAVE_IRQ_EXIT_ON_IRQ_STACK diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index feeeaa60697c..51b9c97751bf 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -32,7 +32,6 @@ config RISCV select HAVE_MEMBLOCK_NODE_MAP select HAVE_DMA_CONTIGUOUS select HAVE_FUTEX_CMPXCHG if FUTEX - select HAVE_GENERIC_DMA_COHERENT select HAVE_PERF_EVENTS select HAVE_SYSCALL_TRACEPOINTS select IRQ_DOMAIN diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig index a9c36f95744a..a3d2a24e75c7 100644 --- a/arch/sh/Kconfig +++ b/arch/sh/Kconfig @@ -7,11 +7,11 @@ config SUPERH select ARCH_NO_COHERENT_DMA_MMAP if !MMU select HAVE_PATA_PLATFORM select CLKDEV_LOOKUP + select DMA_DECLARE_COHERENT select HAVE_IDE if HAS_IOPORT_MAP select HAVE_MEMBLOCK_NODE_MAP select ARCH_DISCARD_MEMBLOCK select HAVE_OPROFILE - select HAVE_GENERIC_DMA_COHERENT select HAVE_ARCH_TRACEHOOK select HAVE_PERF_EVENTS select HAVE_DEBUG_BUGVERBOSE diff --git a/arch/unicore32/Kconfig b/arch/unicore32/Kconfig index c3a41bfe161b..6d2891d37e32 100644 --- a/arch/unicore32/Kconfig +++ b/arch/unicore32/Kconfig @@ -4,7 +4,6 @@ config UNICORE32 select ARCH_HAS_DEVMEM_IS_ALLOWED select ARCH_MIGHT_HAVE_PC_PARPORT select ARCH_MIGHT_HAVE_PC_SERIO - select HAVE_GENERIC_DMA_COHERENT select HAVE_KERNEL_GZIP select HAVE_KERNEL_BZIP2 select GENERIC_ATOMIC64 diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 26387c7bf305..0e33dede053e 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -15,7 +15,6 @@ config X86_32 select CLKSRC_I8253 select CLONE_BACKWARDS select HAVE_AOUT - select HAVE_GENERIC_DMA_COHERENT select MODULES_USE_ELF_REL select OLD_SIGACTION diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig index f15f6489803d..c3ccf2c7b3ef 100644 --- a/drivers/mfd/Kconfig +++ b/drivers/mfd/Kconfig @@ -1067,6 +1067,7 @@ config MFD_SI476X_CORE config MFD_SM501 tristate "Silicon Motion SM501" depends on HAS_DMA + select DMA_DECLARE_COHERENT ---help--- This is the core driver for the Silicon Motion SM501 multimedia companion chip. This device is a multifunction device which may @@ -1675,6 +1676,7 @@ config MFD_TC6393XB select GPIOLIB select MFD_CORE select MFD_TMIO + select DMA_DECLARE_COHERENT help Support for Toshiba Mobile IO Controller TC6393XB diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig index 3607fd2810e4..37c2ccbefecd 100644 --- a/drivers/of/Kconfig +++ b/drivers/of/Kconfig @@ -43,6 +43,7 @@ config OF_FLATTREE config OF_EARLY_FLATTREE bool + select DMA_DECLARE_COHERENT if HAS_DMA select OF_FLATTREE config OF_PROMTREE @@ -83,7 +84,7 @@ config OF_MDIO config OF_RESERVED_MEM bool depends on OF_EARLY_FLATTREE - default y if HAVE_GENERIC_DMA_COHERENT || DMA_CMA + default y if DMA_DECLARE_COHERENT || DMA_CMA config OF_RESOLVE bool diff --git a/include/linux/device.h b/include/linux/device.h index be544400acdd..c52d90348cef 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -1017,7 +1017,7 @@ struct device { struct list_head dma_pools; /* dma pools (if dma'ble) */ -#ifdef CONFIG_HAVE_GENERIC_DMA_COHERENT +#ifdef CONFIG_DMA_DECLARE_COHERENT struct dma_coherent_mem *dma_mem; /* internal for coherent mem override */ #endif diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index 4210c5c1dd21..e29441b8b3b7 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -153,7 +153,7 @@ static inline int is_device_dma_capable(struct device *dev) return dev->dma_mask != NULL && *dev->dma_mask != DMA_MASK_NONE; } -#ifdef CONFIG_HAVE_GENERIC_DMA_COHERENT +#ifdef CONFIG_DMA_DECLARE_COHERENT /* * These three functions are only for dma allocator. * Don't use them in device drivers. @@ -192,7 +192,7 @@ static inline int dma_mmap_from_global_coherent(struct vm_area_struct *vma, { return 0; } -#endif /* CONFIG_HAVE_GENERIC_DMA_COHERENT */ +#endif /* CONFIG_DMA_DECLARE_COHERENT */ static inline bool dma_is_direct(const struct dma_map_ops *ops) { @@ -739,7 +739,7 @@ static inline int dma_get_cache_alignment(void) /* flags for the coherent memory api */ #define DMA_MEMORY_EXCLUSIVE 0x01 -#ifdef CONFIG_HAVE_GENERIC_DMA_COHERENT +#ifdef CONFIG_DMA_DECLARE_COHERENT int dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr, dma_addr_t device_addr, size_t size, int flags); void dma_release_declared_memory(struct device *dev); @@ -764,7 +764,7 @@ dma_mark_declared_memory_occupied(struct device *dev, { return ERR_PTR(-EBUSY); } -#endif /* CONFIG_HAVE_GENERIC_DMA_COHERENT */ +#endif /* CONFIG_DMA_DECLARE_COHERENT */ static inline void *dmam_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_handle, gfp_t gfp) diff --git a/kernel/dma/Kconfig b/kernel/dma/Kconfig index bde9179c6ed7..24d45c78c671 100644 --- a/kernel/dma/Kconfig +++ b/kernel/dma/Kconfig @@ -16,7 +16,7 @@ config ARCH_DMA_ADDR_T_64BIT config ARCH_HAS_DMA_COHERENCE_H bool -config HAVE_GENERIC_DMA_COHERENT +config DMA_DECLARE_COHERENT bool config ARCH_HAS_SETUP_DMA_OPS diff --git a/kernel/dma/Makefile b/kernel/dma/Makefile index 72ff6e46aa86..d237cf3dc181 100644 --- a/kernel/dma/Makefile +++ b/kernel/dma/Makefile @@ -2,7 +2,7 @@ obj-$(CONFIG_HAS_DMA) += mapping.o direct.o dummy.o obj-$(CONFIG_DMA_CMA) += contiguous.o -obj-$(CONFIG_HAVE_GENERIC_DMA_COHERENT) += coherent.o +obj-$(CONFIG_DMA_DECLARE_COHERENT) += coherent.o obj-$(CONFIG_DMA_VIRT_OPS) += virt.o obj-$(CONFIG_DMA_API_DEBUG) += debug.o obj-$(CONFIG_SWIOTLB) += swiotlb.o From ddb26d8e1e97af2385cdcabc51e73bf706a6437c Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 13 Feb 2019 19:19:08 +0100 Subject: [PATCH 14/21] dma-mapping: move CONFIG_DMA_CMA to kernel/dma/Kconfig This is where all the related code already lives. Signed-off-by: Christoph Hellwig Reviewed-by: Greg Kroah-Hartman --- drivers/base/Kconfig | 77 -------------------------------------------- kernel/dma/Kconfig | 77 ++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 77 insertions(+), 77 deletions(-) diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig index 3e63a900b330..059700ea3521 100644 --- a/drivers/base/Kconfig +++ b/drivers/base/Kconfig @@ -191,83 +191,6 @@ config DMA_FENCE_TRACE lockup related problems for dma-buffers shared across multiple devices. -config DMA_CMA - bool "DMA Contiguous Memory Allocator" - depends on HAVE_DMA_CONTIGUOUS && CMA - help - This enables the Contiguous Memory Allocator which allows drivers - to allocate big physically-contiguous blocks of memory for use with - hardware components that do not support I/O map nor scatter-gather. - - You can disable CMA by specifying "cma=0" on the kernel's command - line. - - For more information see . - If unsure, say "n". - -if DMA_CMA -comment "Default contiguous memory area size:" - -config CMA_SIZE_MBYTES - int "Size in Mega Bytes" - depends on !CMA_SIZE_SEL_PERCENTAGE - default 0 if X86 - default 16 - help - Defines the size (in MiB) of the default memory area for Contiguous - Memory Allocator. If the size of 0 is selected, CMA is disabled by - default, but it can be enabled by passing cma=size[MG] to the kernel. - - -config CMA_SIZE_PERCENTAGE - int "Percentage of total memory" - depends on !CMA_SIZE_SEL_MBYTES - default 0 if X86 - default 10 - help - Defines the size of the default memory area for Contiguous Memory - Allocator as a percentage of the total memory in the system. - If 0 percent is selected, CMA is disabled by default, but it can be - enabled by passing cma=size[MG] to the kernel. - -choice - prompt "Selected region size" - default CMA_SIZE_SEL_MBYTES - -config CMA_SIZE_SEL_MBYTES - bool "Use mega bytes value only" - -config CMA_SIZE_SEL_PERCENTAGE - bool "Use percentage value only" - -config CMA_SIZE_SEL_MIN - bool "Use lower value (minimum)" - -config CMA_SIZE_SEL_MAX - bool "Use higher value (maximum)" - -endchoice - -config CMA_ALIGNMENT - int "Maximum PAGE_SIZE order of alignment for contiguous buffers" - range 4 12 - default 8 - help - DMA mapping framework by default aligns all buffers to the smallest - PAGE_SIZE order which is greater than or equal to the requested buffer - size. This works well for buffers up to a few hundreds kilobytes, but - for larger buffers it just a memory waste. With this parameter you can - specify the maximum PAGE_SIZE order for contiguous buffers. Larger - buffers will be aligned only to this specified order. The order is - expressed as a power of two multiplied by the PAGE_SIZE. - - For example, if your system defaults to 4KiB pages, the order value - of 8 means that the buffers will be aligned up to 1MiB only. - - If unsure, leave the default value "8". - -endif - config GENERIC_ARCH_TOPOLOGY bool help diff --git a/kernel/dma/Kconfig b/kernel/dma/Kconfig index 24d45c78c671..212aac7c675f 100644 --- a/kernel/dma/Kconfig +++ b/kernel/dma/Kconfig @@ -60,6 +60,83 @@ config DMA_DIRECT_REMAP bool select DMA_REMAP +config DMA_CMA + bool "DMA Contiguous Memory Allocator" + depends on HAVE_DMA_CONTIGUOUS && CMA + help + This enables the Contiguous Memory Allocator which allows drivers + to allocate big physically-contiguous blocks of memory for use with + hardware components that do not support I/O map nor scatter-gather. + + You can disable CMA by specifying "cma=0" on the kernel's command + line. + + For more information see . + If unsure, say "n". + +if DMA_CMA +comment "Default contiguous memory area size:" + +config CMA_SIZE_MBYTES + int "Size in Mega Bytes" + depends on !CMA_SIZE_SEL_PERCENTAGE + default 0 if X86 + default 16 + help + Defines the size (in MiB) of the default memory area for Contiguous + Memory Allocator. If the size of 0 is selected, CMA is disabled by + default, but it can be enabled by passing cma=size[MG] to the kernel. + + +config CMA_SIZE_PERCENTAGE + int "Percentage of total memory" + depends on !CMA_SIZE_SEL_MBYTES + default 0 if X86 + default 10 + help + Defines the size of the default memory area for Contiguous Memory + Allocator as a percentage of the total memory in the system. + If 0 percent is selected, CMA is disabled by default, but it can be + enabled by passing cma=size[MG] to the kernel. + +choice + prompt "Selected region size" + default CMA_SIZE_SEL_MBYTES + +config CMA_SIZE_SEL_MBYTES + bool "Use mega bytes value only" + +config CMA_SIZE_SEL_PERCENTAGE + bool "Use percentage value only" + +config CMA_SIZE_SEL_MIN + bool "Use lower value (minimum)" + +config CMA_SIZE_SEL_MAX + bool "Use higher value (maximum)" + +endchoice + +config CMA_ALIGNMENT + int "Maximum PAGE_SIZE order of alignment for contiguous buffers" + range 4 12 + default 8 + help + DMA mapping framework by default aligns all buffers to the smallest + PAGE_SIZE order which is greater than or equal to the requested buffer + size. This works well for buffers up to a few hundreds kilobytes, but + for larger buffers it just a memory waste. With this parameter you can + specify the maximum PAGE_SIZE order for contiguous buffers. Larger + buffers will be aligned only to this specified order. The order is + expressed as a power of two multiplied by the PAGE_SIZE. + + For example, if your system defaults to 4KiB pages, the order value + of 8 means that the buffers will be aligned up to 1MiB only. + + If unsure, leave the default value "8". + +endif + config DMA_API_DEBUG bool "Enable debugging of DMA-API usage" select NEED_DMA_MAP_STATE From 91a6fda95cb67c94b887355690d1923a7eb6f630 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 25 Dec 2018 17:27:14 +0100 Subject: [PATCH 15/21] dma-mapping: remove dma_mark_declared_memory_occupied This API is not used anywhere, so remove it. Signed-off-by: Christoph Hellwig --- Documentation/DMA-API.txt | 17 ----------------- include/linux/dma-mapping.h | 9 --------- kernel/dma/coherent.c | 23 ----------------------- 3 files changed, 49 deletions(-) diff --git a/Documentation/DMA-API.txt b/Documentation/DMA-API.txt index 78114ee63057..b9d0cba83877 100644 --- a/Documentation/DMA-API.txt +++ b/Documentation/DMA-API.txt @@ -605,23 +605,6 @@ unconditionally having removed all the required structures. It is the driver's job to ensure that no parts of this memory region are currently in use. -:: - - void * - dma_mark_declared_memory_occupied(struct device *dev, - dma_addr_t device_addr, size_t size) - -This is used to occupy specific regions of the declared space -(dma_alloc_coherent() will hand out the first free region it finds). - -device_addr is the *device* address of the region requested. - -size is the size (and should be a page-sized multiple). - -The return value will be either a pointer to the processor virtual -address of the memory, or an error (via PTR_ERR()) if any part of the -region is occupied. - Part III - Debug drivers use of the DMA-API ------------------------------------------- diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index e29441b8b3b7..d29faadf6ef2 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -743,8 +743,6 @@ static inline int dma_get_cache_alignment(void) int dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr, dma_addr_t device_addr, size_t size, int flags); void dma_release_declared_memory(struct device *dev); -void *dma_mark_declared_memory_occupied(struct device *dev, - dma_addr_t device_addr, size_t size); #else static inline int dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr, @@ -757,13 +755,6 @@ static inline void dma_release_declared_memory(struct device *dev) { } - -static inline void * -dma_mark_declared_memory_occupied(struct device *dev, - dma_addr_t device_addr, size_t size) -{ - return ERR_PTR(-EBUSY); -} #endif /* CONFIG_DMA_DECLARE_COHERENT */ static inline void *dmam_alloc_coherent(struct device *dev, size_t size, diff --git a/kernel/dma/coherent.c b/kernel/dma/coherent.c index 4b76aba574c2..1d12a31af6d7 100644 --- a/kernel/dma/coherent.c +++ b/kernel/dma/coherent.c @@ -137,29 +137,6 @@ void dma_release_declared_memory(struct device *dev) } EXPORT_SYMBOL(dma_release_declared_memory); -void *dma_mark_declared_memory_occupied(struct device *dev, - dma_addr_t device_addr, size_t size) -{ - struct dma_coherent_mem *mem = dev->dma_mem; - unsigned long flags; - int pos, err; - - size += device_addr & ~PAGE_MASK; - - if (!mem) - return ERR_PTR(-EINVAL); - - spin_lock_irqsave(&mem->spinlock, flags); - pos = PFN_DOWN(device_addr - dma_get_device_base(dev, mem)); - err = bitmap_allocate_region(mem->bitmap, pos, get_order(size)); - spin_unlock_irqrestore(&mem->spinlock, flags); - - if (err != 0) - return ERR_PTR(err); - return mem->virt_base + (pos << PAGE_SHIFT); -} -EXPORT_SYMBOL(dma_mark_declared_memory_occupied); - static void *__dma_alloc_from_coherent(struct dma_coherent_mem *mem, ssize_t size, dma_addr_t *dma_handle) { From 82c5de0ab8dbd6035223ad69e76bd8a88a0a9399 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 25 Dec 2018 13:29:54 +0100 Subject: [PATCH 16/21] dma-mapping: remove the DMA_MEMORY_EXCLUSIVE flag All users of dma_declare_coherent want their allocations to be exclusive, so default to exclusive allocations. Signed-off-by: Christoph Hellwig Reviewed-by: Greg Kroah-Hartman --- Documentation/DMA-API.txt | 9 +------ arch/arm/mach-imx/mach-imx27_visstrim_m10.c | 12 +++------ arch/arm/mach-imx/mach-mx31moboard.c | 3 +-- arch/sh/boards/mach-ap325rxa/setup.c | 5 ++-- arch/sh/boards/mach-ecovec24/setup.c | 6 ++--- arch/sh/boards/mach-kfr2r09/setup.c | 5 ++-- arch/sh/boards/mach-migor/setup.c | 5 ++-- arch/sh/boards/mach-se/7724/setup.c | 6 ++--- arch/sh/drivers/pci/fixups-dreamcast.c | 3 +-- .../soc_camera/sh_mobile_ceu_camera.c | 3 +-- drivers/usb/host/ohci-sm501.c | 3 +-- drivers/usb/host/ohci-tmio.c | 2 +- include/linux/dma-mapping.h | 7 ++---- kernel/dma/coherent.c | 25 ++++++------------- 14 files changed, 29 insertions(+), 65 deletions(-) diff --git a/Documentation/DMA-API.txt b/Documentation/DMA-API.txt index b9d0cba83877..38e561b773b4 100644 --- a/Documentation/DMA-API.txt +++ b/Documentation/DMA-API.txt @@ -566,8 +566,7 @@ boundaries when doing this. int dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr, - dma_addr_t device_addr, size_t size, int - flags) + dma_addr_t device_addr, size_t size); Declare region of memory to be handed out by dma_alloc_coherent() when it's asked for coherent memory for this device. @@ -581,12 +580,6 @@ dma_addr_t in dma_alloc_coherent()). size is the size of the area (must be multiples of PAGE_SIZE). -flags can be ORed together and are: - -- DMA_MEMORY_EXCLUSIVE - only allocate memory from the declared regions. - Do not allow dma_alloc_coherent() to fall back to system memory when - it's out of memory in the declared region. - As a simplification for the platforms, only *one* such region of memory may be declared per device. diff --git a/arch/arm/mach-imx/mach-imx27_visstrim_m10.c b/arch/arm/mach-imx/mach-imx27_visstrim_m10.c index 5169dfba9718..07d4fcfe5c2e 100644 --- a/arch/arm/mach-imx/mach-imx27_visstrim_m10.c +++ b/arch/arm/mach-imx/mach-imx27_visstrim_m10.c @@ -258,8 +258,7 @@ static void __init visstrim_analog_camera_init(void) return; dma_declare_coherent_memory(&pdev->dev, mx2_camera_base, - mx2_camera_base, MX2_CAMERA_BUF_SIZE, - DMA_MEMORY_EXCLUSIVE); + mx2_camera_base, MX2_CAMERA_BUF_SIZE); } static void __init visstrim_reserve(void) @@ -445,8 +444,7 @@ static void __init visstrim_coda_init(void) dma_declare_coherent_memory(&pdev->dev, mx2_camera_base + MX2_CAMERA_BUF_SIZE, mx2_camera_base + MX2_CAMERA_BUF_SIZE, - MX2_CAMERA_BUF_SIZE, - DMA_MEMORY_EXCLUSIVE); + MX2_CAMERA_BUF_SIZE); } /* DMA deinterlace */ @@ -465,8 +463,7 @@ static void __init visstrim_deinterlace_init(void) dma_declare_coherent_memory(&pdev->dev, mx2_camera_base + 2 * MX2_CAMERA_BUF_SIZE, mx2_camera_base + 2 * MX2_CAMERA_BUF_SIZE, - MX2_CAMERA_BUF_SIZE, - DMA_MEMORY_EXCLUSIVE); + MX2_CAMERA_BUF_SIZE); } /* Emma-PrP for format conversion */ @@ -485,8 +482,7 @@ static void __init visstrim_emmaprp_init(void) */ ret = dma_declare_coherent_memory(&pdev->dev, mx2_camera_base, mx2_camera_base, - MX2_CAMERA_BUF_SIZE, - DMA_MEMORY_EXCLUSIVE); + MX2_CAMERA_BUF_SIZE); if (ret) pr_err("Failed to declare memory for emmaprp\n"); } diff --git a/arch/arm/mach-imx/mach-mx31moboard.c b/arch/arm/mach-imx/mach-mx31moboard.c index 643a3d749703..fe50f4cf00a7 100644 --- a/arch/arm/mach-imx/mach-mx31moboard.c +++ b/arch/arm/mach-imx/mach-mx31moboard.c @@ -475,8 +475,7 @@ static int __init mx31moboard_init_cam(void) ret = dma_declare_coherent_memory(&pdev->dev, mx3_camera_base, mx3_camera_base, - MX3_CAMERA_BUF_SIZE, - DMA_MEMORY_EXCLUSIVE); + MX3_CAMERA_BUF_SIZE); if (ret) goto err; diff --git a/arch/sh/boards/mach-ap325rxa/setup.c b/arch/sh/boards/mach-ap325rxa/setup.c index 8f234d0435aa..7899b4f51fdd 100644 --- a/arch/sh/boards/mach-ap325rxa/setup.c +++ b/arch/sh/boards/mach-ap325rxa/setup.c @@ -529,9 +529,8 @@ static int __init ap325rxa_devices_setup(void) device_initialize(&ap325rxa_ceu_device.dev); arch_setup_pdev_archdata(&ap325rxa_ceu_device); dma_declare_coherent_memory(&ap325rxa_ceu_device.dev, - ceu_dma_membase, ceu_dma_membase, - ceu_dma_membase + CEU_BUFFER_MEMORY_SIZE - 1, - DMA_MEMORY_EXCLUSIVE); + ceu_dma_membase, ceu_dma_membase, + ceu_dma_membase + CEU_BUFFER_MEMORY_SIZE - 1); platform_device_add(&ap325rxa_ceu_device); diff --git a/arch/sh/boards/mach-ecovec24/setup.c b/arch/sh/boards/mach-ecovec24/setup.c index 22b4106b8084..eb66754cfb8c 100644 --- a/arch/sh/boards/mach-ecovec24/setup.c +++ b/arch/sh/boards/mach-ecovec24/setup.c @@ -1440,8 +1440,7 @@ static int __init arch_setup(void) dma_declare_coherent_memory(&ecovec_ceu_devices[0]->dev, ceu0_dma_membase, ceu0_dma_membase, ceu0_dma_membase + - CEU_BUFFER_MEMORY_SIZE - 1, - DMA_MEMORY_EXCLUSIVE); + CEU_BUFFER_MEMORY_SIZE - 1); platform_device_add(ecovec_ceu_devices[0]); device_initialize(&ecovec_ceu_devices[1]->dev); @@ -1449,8 +1448,7 @@ static int __init arch_setup(void) dma_declare_coherent_memory(&ecovec_ceu_devices[1]->dev, ceu1_dma_membase, ceu1_dma_membase, ceu1_dma_membase + - CEU_BUFFER_MEMORY_SIZE - 1, - DMA_MEMORY_EXCLUSIVE); + CEU_BUFFER_MEMORY_SIZE - 1); platform_device_add(ecovec_ceu_devices[1]); gpiod_add_lookup_table(&cn12_power_gpiod_table); diff --git a/arch/sh/boards/mach-kfr2r09/setup.c b/arch/sh/boards/mach-kfr2r09/setup.c index 203d249a0a2b..b8bf67c86eab 100644 --- a/arch/sh/boards/mach-kfr2r09/setup.c +++ b/arch/sh/boards/mach-kfr2r09/setup.c @@ -603,9 +603,8 @@ static int __init kfr2r09_devices_setup(void) device_initialize(&kfr2r09_ceu_device.dev); arch_setup_pdev_archdata(&kfr2r09_ceu_device); dma_declare_coherent_memory(&kfr2r09_ceu_device.dev, - ceu_dma_membase, ceu_dma_membase, - ceu_dma_membase + CEU_BUFFER_MEMORY_SIZE - 1, - DMA_MEMORY_EXCLUSIVE); + ceu_dma_membase, ceu_dma_membase, + ceu_dma_membase + CEU_BUFFER_MEMORY_SIZE - 1); platform_device_add(&kfr2r09_ceu_device); diff --git a/arch/sh/boards/mach-migor/setup.c b/arch/sh/boards/mach-migor/setup.c index f4ad33c6d2aa..bcd249e6cfcc 100644 --- a/arch/sh/boards/mach-migor/setup.c +++ b/arch/sh/boards/mach-migor/setup.c @@ -603,9 +603,8 @@ static int __init migor_devices_setup(void) device_initialize(&migor_ceu_device.dev); arch_setup_pdev_archdata(&migor_ceu_device); dma_declare_coherent_memory(&migor_ceu_device.dev, - ceu_dma_membase, ceu_dma_membase, - ceu_dma_membase + CEU_BUFFER_MEMORY_SIZE - 1, - DMA_MEMORY_EXCLUSIVE); + ceu_dma_membase, ceu_dma_membase, + ceu_dma_membase + CEU_BUFFER_MEMORY_SIZE - 1); platform_device_add(&migor_ceu_device); diff --git a/arch/sh/boards/mach-se/7724/setup.c b/arch/sh/boards/mach-se/7724/setup.c index fdbec22ae687..13c2d3ce78f4 100644 --- a/arch/sh/boards/mach-se/7724/setup.c +++ b/arch/sh/boards/mach-se/7724/setup.c @@ -941,8 +941,7 @@ static int __init devices_setup(void) dma_declare_coherent_memory(&ms7724se_ceu_devices[0]->dev, ceu0_dma_membase, ceu0_dma_membase, ceu0_dma_membase + - CEU_BUFFER_MEMORY_SIZE - 1, - DMA_MEMORY_EXCLUSIVE); + CEU_BUFFER_MEMORY_SIZE - 1); platform_device_add(ms7724se_ceu_devices[0]); device_initialize(&ms7724se_ceu_devices[1]->dev); @@ -950,8 +949,7 @@ static int __init devices_setup(void) dma_declare_coherent_memory(&ms7724se_ceu_devices[1]->dev, ceu1_dma_membase, ceu1_dma_membase, ceu1_dma_membase + - CEU_BUFFER_MEMORY_SIZE - 1, - DMA_MEMORY_EXCLUSIVE); + CEU_BUFFER_MEMORY_SIZE - 1); platform_device_add(ms7724se_ceu_devices[1]); return platform_add_devices(ms7724se_devices, diff --git a/arch/sh/drivers/pci/fixups-dreamcast.c b/arch/sh/drivers/pci/fixups-dreamcast.c index dfdbd05b6eb1..7be8694c0d13 100644 --- a/arch/sh/drivers/pci/fixups-dreamcast.c +++ b/arch/sh/drivers/pci/fixups-dreamcast.c @@ -63,8 +63,7 @@ static void gapspci_fixup_resources(struct pci_dev *dev) BUG_ON(dma_declare_coherent_memory(&dev->dev, res.start, region.start, - resource_size(&res), - DMA_MEMORY_EXCLUSIVE)); + resource_size(&res))); break; default: printk("PCI: Failed resource fixup\n"); diff --git a/drivers/media/platform/soc_camera/sh_mobile_ceu_camera.c b/drivers/media/platform/soc_camera/sh_mobile_ceu_camera.c index 6803f744e307..cc357b8db1dc 100644 --- a/drivers/media/platform/soc_camera/sh_mobile_ceu_camera.c +++ b/drivers/media/platform/soc_camera/sh_mobile_ceu_camera.c @@ -1708,8 +1708,7 @@ static int sh_mobile_ceu_probe(struct platform_device *pdev) if (res) { err = dma_declare_coherent_memory(&pdev->dev, res->start, res->start, - resource_size(res), - DMA_MEMORY_EXCLUSIVE); + resource_size(res)); if (err) { dev_err(&pdev->dev, "Unable to declare CEU memory.\n"); return err; diff --git a/drivers/usb/host/ohci-sm501.c b/drivers/usb/host/ohci-sm501.c index c9233cddf9a2..c26228c25f99 100644 --- a/drivers/usb/host/ohci-sm501.c +++ b/drivers/usb/host/ohci-sm501.c @@ -126,8 +126,7 @@ static int ohci_hcd_sm501_drv_probe(struct platform_device *pdev) retval = dma_declare_coherent_memory(dev, mem->start, mem->start - mem->parent->start, - resource_size(mem), - DMA_MEMORY_EXCLUSIVE); + resource_size(mem)); if (retval) { dev_err(dev, "cannot declare coherent memory\n"); goto err1; diff --git a/drivers/usb/host/ohci-tmio.c b/drivers/usb/host/ohci-tmio.c index a631dbb369d7..f88a0370659f 100644 --- a/drivers/usb/host/ohci-tmio.c +++ b/drivers/usb/host/ohci-tmio.c @@ -225,7 +225,7 @@ static int ohci_hcd_tmio_drv_probe(struct platform_device *dev) } ret = dma_declare_coherent_memory(&dev->dev, sram->start, sram->start, - resource_size(sram), DMA_MEMORY_EXCLUSIVE); + resource_size(sram)); if (ret) goto err_dma_declare; diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index d29faadf6ef2..70ad15758a70 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -736,17 +736,14 @@ static inline int dma_get_cache_alignment(void) return 1; } -/* flags for the coherent memory api */ -#define DMA_MEMORY_EXCLUSIVE 0x01 - #ifdef CONFIG_DMA_DECLARE_COHERENT int dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr, - dma_addr_t device_addr, size_t size, int flags); + dma_addr_t device_addr, size_t size); void dma_release_declared_memory(struct device *dev); #else static inline int dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr, - dma_addr_t device_addr, size_t size, int flags) + dma_addr_t device_addr, size_t size) { return -ENOSYS; } diff --git a/kernel/dma/coherent.c b/kernel/dma/coherent.c index 1d12a31af6d7..29fd6590dc1e 100644 --- a/kernel/dma/coherent.c +++ b/kernel/dma/coherent.c @@ -14,7 +14,6 @@ struct dma_coherent_mem { dma_addr_t device_base; unsigned long pfn_base; int size; - int flags; unsigned long *bitmap; spinlock_t spinlock; bool use_dev_dma_pfn_offset; @@ -38,9 +37,9 @@ static inline dma_addr_t dma_get_device_base(struct device *dev, return mem->device_base; } -static int dma_init_coherent_memory( - phys_addr_t phys_addr, dma_addr_t device_addr, size_t size, int flags, - struct dma_coherent_mem **mem) +static int dma_init_coherent_memory(phys_addr_t phys_addr, + dma_addr_t device_addr, size_t size, + struct dma_coherent_mem **mem) { struct dma_coherent_mem *dma_mem = NULL; void *mem_base = NULL; @@ -73,7 +72,6 @@ static int dma_init_coherent_memory( dma_mem->device_base = device_addr; dma_mem->pfn_base = PFN_DOWN(phys_addr); dma_mem->size = pages; - dma_mem->flags = flags; spin_lock_init(&dma_mem->spinlock); *mem = dma_mem; @@ -110,12 +108,12 @@ static int dma_assign_coherent_memory(struct device *dev, } int dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr, - dma_addr_t device_addr, size_t size, int flags) + dma_addr_t device_addr, size_t size) { struct dma_coherent_mem *mem; int ret; - ret = dma_init_coherent_memory(phys_addr, device_addr, size, flags, &mem); + ret = dma_init_coherent_memory(phys_addr, device_addr, size, &mem); if (ret) return ret; @@ -190,15 +188,7 @@ int dma_alloc_from_dev_coherent(struct device *dev, ssize_t size, return 0; *ret = __dma_alloc_from_coherent(mem, size, dma_handle); - if (*ret) - return 1; - - /* - * In the case where the allocation can not be satisfied from the - * per-device area, try to fall back to generic memory if the - * constraints allow it. - */ - return mem->flags & DMA_MEMORY_EXCLUSIVE; + return 1; } void *dma_alloc_from_global_coherent(ssize_t size, dma_addr_t *dma_handle) @@ -327,8 +317,7 @@ static int rmem_dma_device_init(struct reserved_mem *rmem, struct device *dev) if (!mem) { ret = dma_init_coherent_memory(rmem->base, rmem->base, - rmem->size, - DMA_MEMORY_EXCLUSIVE, &mem); + rmem->size, &mem); if (ret) { pr_err("Reserved memory: failed to init DMA memory pool at %pa, size %ld MiB\n", &rmem->base, (unsigned long)rmem->size / SZ_1M); From 7753a91e78811f6fcefc9f59630286a698b814b2 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 14 Feb 2019 18:17:33 +0100 Subject: [PATCH 17/21] ccio: allow large DMA masks There is no harm in setting a 64-bit mask even if we don't need it, and the current ccio code is one of the few place in the kernel still rejecting larger than required DMA masks. Signed-off-by: Christoph Hellwig --- drivers/parisc/ccio-dma.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/parisc/ccio-dma.c b/drivers/parisc/ccio-dma.c index 8d2fc84119c6..24a68fb7b2f9 100644 --- a/drivers/parisc/ccio-dma.c +++ b/drivers/parisc/ccio-dma.c @@ -710,8 +710,8 @@ ccio_dma_supported(struct device *dev, u64 mask) return 0; } - /* only support 32-bit devices (ie PCI/GSC) */ - return (int)(mask == 0xffffffffUL); + /* only support 32-bit or better devices (ie PCI/GSC) */ + return (int)(mask >= 0xffffffffUL); } /** From c54fc984dae5fb0007ddfc46dabde6631735689d Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 15 Feb 2019 09:06:31 +0100 Subject: [PATCH 18/21] sparc64: refactor the ali DMA quirk Do the quirk first in the dma_supported routines, as we don't need any of the other checks for it, and remove the duplicate mask checking that is already done by the callers. Signed-off-by: Christoph Hellwig Acked-by: David S. Miller --- arch/sparc/kernel/iommu.c | 7 +++--- arch/sparc/kernel/kernel.h | 6 ++++- arch/sparc/kernel/pci.c | 46 ++++++++++++----------------------- arch/sparc/kernel/pci_sun4v.c | 5 +++- 4 files changed, 27 insertions(+), 37 deletions(-) diff --git a/arch/sparc/kernel/iommu.c b/arch/sparc/kernel/iommu.c index b1a09080e8da..0c253f1c852e 100644 --- a/arch/sparc/kernel/iommu.c +++ b/arch/sparc/kernel/iommu.c @@ -745,14 +745,13 @@ static int dma_4u_supported(struct device *dev, u64 device_mask) { struct iommu *iommu = dev->archdata.iommu; + if (ali_sound_dma_hack(dev, device_mask)) + return 1; + if (device_mask > DMA_BIT_MASK(32)) return 0; if ((device_mask & iommu->dma_addr_mask) == iommu->dma_addr_mask) return 1; -#ifdef CONFIG_PCI - if (dev_is_pci(dev)) - return pci64_dma_supported(to_pci_dev(dev), device_mask); -#endif return 0; } diff --git a/arch/sparc/kernel/kernel.h b/arch/sparc/kernel/kernel.h index ddffd368e057..f6f498ba3198 100644 --- a/arch/sparc/kernel/kernel.h +++ b/arch/sparc/kernel/kernel.h @@ -45,7 +45,11 @@ void __irq_entry smp_receive_signal_client(int irq, struct pt_regs *regs); void __irq_entry smp_kgdb_capture_client(int irq, struct pt_regs *regs); /* pci.c */ -int pci64_dma_supported(struct pci_dev *pdev, u64 device_mask); +#ifdef CONFIG_PCI +int ali_sound_dma_hack(struct device *dev, u64 device_mask); +#else +#define ali_sound_dma_hack(dev, mask) (0) +#endif /* signal32.c */ void do_sigreturn32(struct pt_regs *regs); diff --git a/arch/sparc/kernel/pci.c b/arch/sparc/kernel/pci.c index bcfec6a85d23..5ed43828e078 100644 --- a/arch/sparc/kernel/pci.c +++ b/arch/sparc/kernel/pci.c @@ -956,51 +956,35 @@ void arch_teardown_msi_irq(unsigned int irq) } #endif /* !(CONFIG_PCI_MSI) */ -static void ali_sound_dma_hack(struct pci_dev *pdev, int set_bit) +/* ALI sound chips generate 31-bits of DMA, a special register + * determines what bit 31 is emitted as. + */ +int ali_sound_dma_hack(struct device *dev, u64 device_mask) { + struct iommu *iommu = dev->archdata.iommu; struct pci_dev *ali_isa_bridge; u8 val; - /* ALI sound chips generate 31-bits of DMA, a special register - * determines what bit 31 is emitted as. - */ + if (!dev_is_pci(dev)) + return 0; + + if (to_pci_dev(dev)->vendor != PCI_VENDOR_ID_AL || + to_pci_dev(dev)->device != PCI_DEVICE_ID_AL_M5451 || + device_mask != 0x7fffffff) + return 0; + ali_isa_bridge = pci_get_device(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M1533, NULL); pci_read_config_byte(ali_isa_bridge, 0x7e, &val); - if (set_bit) + if (iommu->dma_addr_mask & 0x80000000) val |= 0x01; else val &= ~0x01; pci_write_config_byte(ali_isa_bridge, 0x7e, val); pci_dev_put(ali_isa_bridge); -} - -int pci64_dma_supported(struct pci_dev *pdev, u64 device_mask) -{ - u64 dma_addr_mask; - - if (pdev == NULL) { - dma_addr_mask = 0xffffffff; - } else { - struct iommu *iommu = pdev->dev.archdata.iommu; - - dma_addr_mask = iommu->dma_addr_mask; - - if (pdev->vendor == PCI_VENDOR_ID_AL && - pdev->device == PCI_DEVICE_ID_AL_M5451 && - device_mask == 0x7fffffff) { - ali_sound_dma_hack(pdev, - (dma_addr_mask & 0x80000000) != 0); - return 1; - } - } - - if (device_mask >= (1UL << 32UL)) - return 0; - - return (device_mask & dma_addr_mask) == dma_addr_mask; + return 1; } void pci_resource_to_user(const struct pci_dev *pdev, int bar, diff --git a/arch/sparc/kernel/pci_sun4v.c b/arch/sparc/kernel/pci_sun4v.c index fa0e42b4cbfb..d30eb22b6e11 100644 --- a/arch/sparc/kernel/pci_sun4v.c +++ b/arch/sparc/kernel/pci_sun4v.c @@ -676,6 +676,9 @@ static int dma_4v_supported(struct device *dev, u64 device_mask) struct iommu *iommu = dev->archdata.iommu; u64 dma_addr_mask = iommu->dma_addr_mask; + if (ali_sound_dma_hack(dev, device_mask)) + return 1; + if (device_mask > DMA_BIT_MASK(32)) { if (iommu->atu) dma_addr_mask = iommu->atu->dma_addr_mask; @@ -685,7 +688,7 @@ static int dma_4v_supported(struct device *dev, u64 device_mask) if ((device_mask & dma_addr_mask) == dma_addr_mask) return 1; - return pci64_dma_supported(to_pci_dev(dev), device_mask); + return 0; } static const struct dma_map_ops sun4v_dma_ops = { From 254ecb1601ebbdf0eeda4156f4c55254cb9addaf Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 15 Feb 2019 13:27:30 +0100 Subject: [PATCH 19/21] sparc64/iommu: allow large DMA masks We've been moving to a model where the device just sets the DMA mask supported by it, instead of having to fallback to something it thinks the platform might support. Sparc64 is the remaining holdout forcing drivers to supply a matching mask. Change dma_4u_supported to just check if the supplied dma mask is large enough as nothing in the iommu.c code (or the core DMA code) actually looks at the DMA mask later on. Signed-off-by: Christoph Hellwig Acked-by: David S. Miller --- arch/sparc/kernel/iommu.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/arch/sparc/kernel/iommu.c b/arch/sparc/kernel/iommu.c index 0c253f1c852e..4ae7388b1bff 100644 --- a/arch/sparc/kernel/iommu.c +++ b/arch/sparc/kernel/iommu.c @@ -748,11 +748,9 @@ static int dma_4u_supported(struct device *dev, u64 device_mask) if (ali_sound_dma_hack(dev, device_mask)) return 1; - if (device_mask > DMA_BIT_MASK(32)) + if (device_mask < iommu->dma_addr_mask) return 0; - if ((device_mask & iommu->dma_addr_mask) == iommu->dma_addr_mask) - return 1; - return 0; + return 1; } static const struct dma_map_ops sun4u_dma_ops = { From 24132a419c68f1d69eb8ecc91b3c80d730ecbb59 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 15 Feb 2019 09:30:28 +0100 Subject: [PATCH 20/21] sparc64/pci_sun4v: allow large DMA masks We've been moving to a model where the device just sets the DMA mask supported by it, instead of having to fallback to something it thinks the platform might support. Sparc64 is the remaining holdout forcing drivers to supply a matching mask. Change dma_4v_supported to just check if the supplied dma mask is large enough. and adjust the mapping code to check ATU presence in addition to the DMA mask to decide on the mapping method. Signed-off-by: Christoph Hellwig Acked-by: David S. Miller --- arch/sparc/kernel/pci_sun4v.c | 19 +++++-------------- 1 file changed, 5 insertions(+), 14 deletions(-) diff --git a/arch/sparc/kernel/pci_sun4v.c b/arch/sparc/kernel/pci_sun4v.c index d30eb22b6e11..a8af6023c126 100644 --- a/arch/sparc/kernel/pci_sun4v.c +++ b/arch/sparc/kernel/pci_sun4v.c @@ -92,7 +92,7 @@ static long iommu_batch_flush(struct iommu_batch *p, u64 mask) prot &= (HV_PCI_MAP_ATTR_READ | HV_PCI_MAP_ATTR_WRITE); while (npages != 0) { - if (mask <= DMA_BIT_MASK(32)) { + if (mask <= DMA_BIT_MASK(32) || !pbm->iommu->atu) { num = pci_sun4v_iommu_map(devhandle, HV_PCI_TSBID(0, entry), npages, @@ -208,7 +208,7 @@ static void *dma_4v_alloc_coherent(struct device *dev, size_t size, atu = iommu->atu; mask = dev->coherent_dma_mask; - if (mask <= DMA_BIT_MASK(32)) + if (mask <= DMA_BIT_MASK(32) || !atu) tbl = &iommu->tbl; else tbl = &atu->tbl; @@ -674,21 +674,12 @@ static void dma_4v_unmap_sg(struct device *dev, struct scatterlist *sglist, static int dma_4v_supported(struct device *dev, u64 device_mask) { struct iommu *iommu = dev->archdata.iommu; - u64 dma_addr_mask = iommu->dma_addr_mask; if (ali_sound_dma_hack(dev, device_mask)) return 1; - - if (device_mask > DMA_BIT_MASK(32)) { - if (iommu->atu) - dma_addr_mask = iommu->atu->dma_addr_mask; - else - return 0; - } - - if ((device_mask & dma_addr_mask) == dma_addr_mask) - return 1; - return 0; + if (device_mask < iommu->dma_addr_mask) + return 0; + return 1; } static const struct dma_map_ops sun4v_dma_ops = { From 9eb9e96e97b3381e94cba81d93f4a390c26ca6cb Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 15 Feb 2019 09:01:53 +0100 Subject: [PATCH 21/21] Documentation/DMA-API-HOWTO: update dma_mask sections We don't require drivers to guess a DMA mask that might actually match the system capabilities any more, so fix up the documentation to clear this up. Signed-off-by: Christoph Hellwig --- Documentation/DMA-API-HOWTO.txt | 121 +++++++++++--------------------- 1 file changed, 41 insertions(+), 80 deletions(-) diff --git a/Documentation/DMA-API-HOWTO.txt b/Documentation/DMA-API-HOWTO.txt index f0cc3f772265..1a721d0f35c8 100644 --- a/Documentation/DMA-API-HOWTO.txt +++ b/Documentation/DMA-API-HOWTO.txt @@ -146,114 +146,75 @@ What about block I/O and networking buffers? The block I/O and networking subsystems make sure that the buffers they use are valid for you to DMA from/to. -DMA addressing limitations +DMA addressing capabilities ========================== -Does your device have any DMA addressing limitations? For example, is -your device only capable of driving the low order 24-bits of address? -If so, you need to inform the kernel of this fact. +By default, the kernel assumes that your device can address 32-bits of DMA +addressing. For a 64-bit capable device, this needs to be increased, and for +a device with limitations, it needs to be decreased. -By default, the kernel assumes that your device can address the full -32-bits. For a 64-bit capable device, this needs to be increased. -And for a device with limitations, as discussed in the previous -paragraph, it needs to be decreased. +Special note about PCI: PCI-X specification requires PCI-X devices to support +64-bit addressing (DAC) for all transactions. And at least one platform (SGI +SN2) requires 64-bit consistent allocations to operate correctly when the IO +bus is in PCI-X mode. -Special note about PCI: PCI-X specification requires PCI-X devices to -support 64-bit addressing (DAC) for all transactions. And at least -one platform (SGI SN2) requires 64-bit consistent allocations to -operate correctly when the IO bus is in PCI-X mode. +For correct operation, you must set the DMA mask to inform the kernel about +your devices DMA addressing capabilities. -For correct operation, you must interrogate the kernel in your device -probe routine to see if the DMA controller on the machine can properly -support the DMA addressing limitation your device has. It is good -style to do this even if your device holds the default setting, -because this shows that you did think about these issues wrt. your -device. - -The query is performed via a call to dma_set_mask_and_coherent():: +This is performed via a call to dma_set_mask_and_coherent():: int dma_set_mask_and_coherent(struct device *dev, u64 mask); -which will query the mask for both streaming and coherent APIs together. -If you have some special requirements, then the following two separate -queries can be used instead: +which will set the mask for both streaming and coherent APIs together. If you +have some special requirements, then the following two separate calls can be +used instead: - The query for streaming mappings is performed via a call to + The setup for streaming mappings is performed via a call to dma_set_mask():: int dma_set_mask(struct device *dev, u64 mask); - The query for consistent allocations is performed via a call + The setup for consistent allocations is performed via a call to dma_set_coherent_mask():: int dma_set_coherent_mask(struct device *dev, u64 mask); -Here, dev is a pointer to the device struct of your device, and mask -is a bit mask describing which bits of an address your device -supports. It returns zero if your card can perform DMA properly on -the machine given the address mask you provided. In general, the -device struct of your device is embedded in the bus-specific device -struct of your device. For example, &pdev->dev is a pointer to the -device struct of a PCI device (pdev is a pointer to the PCI device -struct of your device). +Here, dev is a pointer to the device struct of your device, and mask is a bit +mask describing which bits of an address your device supports. Often the +device struct of your device is embedded in the bus-specific device struct of +your device. For example, &pdev->dev is a pointer to the device struct of a +PCI device (pdev is a pointer to the PCI device struct of your device). -If it returns non-zero, your device cannot perform DMA properly on -this platform, and attempting to do so will result in undefined -behavior. You must either use a different mask, or not use DMA. +These calls usually return zero to indicated your device can perform DMA +properly on the machine given the address mask you provided, but they might +return an error if the mask is too small to be supportable on the given +system. If it returns non-zero, your device cannot perform DMA properly on +this platform, and attempting to do so will result in undefined behavior. +You must not use DMA on this device unless the dma_set_mask family of +functions has returned success. -This means that in the failure case, you have three options: +This means that in the failure case, you have two options: -1) Use another DMA mask, if possible (see below). -2) Use some non-DMA mode for data transfer, if possible. -3) Ignore this device and do not initialize it. +1) Use some non-DMA mode for data transfer, if possible. +2) Ignore this device and do not initialize it. -It is recommended that your driver print a kernel KERN_WARNING message -when you end up performing either #2 or #3. In this manner, if a user -of your driver reports that performance is bad or that the device is not -even detected, you can ask them for the kernel messages to find out -exactly why. +It is recommended that your driver print a kernel KERN_WARNING message when +setting the DMA mask fails. In this manner, if a user of your driver reports +that performance is bad or that the device is not even detected, you can ask +them for the kernel messages to find out exactly why. -The standard 32-bit addressing device would do something like this:: +The standard 64-bit addressing device would do something like this:: - if (dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32))) { + if (dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64))) { dev_warn(dev, "mydev: No suitable DMA available\n"); goto ignore_this_device; } -Another common scenario is a 64-bit capable device. The approach here -is to try for 64-bit addressing, but back down to a 32-bit mask that -should not fail. The kernel may fail the 64-bit mask not because the -platform is not capable of 64-bit addressing. Rather, it may fail in -this case simply because 32-bit addressing is done more efficiently -than 64-bit addressing. For example, Sparc64 PCI SAC addressing is -more efficient than DAC addressing. +If the device only supports 32-bit addressing for descriptors in the +coherent allocations, but supports full 64-bits for streaming mappings +it would look like this: -Here is how you would handle a 64-bit capable device which can drive -all 64-bits when accessing streaming DMA:: - - int using_dac; - - if (!dma_set_mask(dev, DMA_BIT_MASK(64))) { - using_dac = 1; - } else if (!dma_set_mask(dev, DMA_BIT_MASK(32))) { - using_dac = 0; - } else { - dev_warn(dev, "mydev: No suitable DMA available\n"); - goto ignore_this_device; - } - -If a card is capable of using 64-bit consistent allocations as well, -the case would look like this:: - - int using_dac, consistent_using_dac; - - if (!dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64))) { - using_dac = 1; - consistent_using_dac = 1; - } else if (!dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32))) { - using_dac = 0; - consistent_using_dac = 0; - } else { + if (dma_set_mask(dev, DMA_BIT_MASK(64))) { dev_warn(dev, "mydev: No suitable DMA available\n"); goto ignore_this_device; }