From 7e2368a21741e2db542330b32aa6fdd8908e7cff Mon Sep 17 00:00:00 2001 From: Baochen Qiang Date: Thu, 28 Aug 2025 16:17:33 +0800 Subject: dma-debug: don't enforce dma mapping check on noncoherent allocations As discussed in [1], there is no need to enforce dma mapping check on noncoherent allocations, a simple test on the returned CPU address is good enough. Add a new pair of debug helpers and use them for noncoherent alloc/free to fix this issue. Fixes: efa70f2fdc84 ("dma-mapping: add a new dma_alloc_pages API") Link: https://lore.kernel.org/all/ff6c1fe6-820f-4e58-8395-df06aa91706c@oss.qualcomm.com # 1 Signed-off-by: Baochen Qiang Signed-off-by: Marek Szyprowski Link: https://lore.kernel.org/r/20250828-dma-debug-fix-noncoherent-dma-check-v1-1-76e9be0dd7fc@oss.qualcomm.com --- kernel/dma/debug.c | 48 +++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 47 insertions(+), 1 deletion(-) (limited to 'kernel/dma/debug.c') diff --git a/kernel/dma/debug.c b/kernel/dma/debug.c index e43c6de2bce4..b82399437db0 100644 --- a/kernel/dma/debug.c +++ b/kernel/dma/debug.c @@ -39,6 +39,7 @@ enum { dma_debug_sg, dma_debug_coherent, dma_debug_resource, + dma_debug_noncoherent, }; enum map_err_types { @@ -141,6 +142,7 @@ static const char *type2name[] = { [dma_debug_sg] = "scatter-gather", [dma_debug_coherent] = "coherent", [dma_debug_resource] = "resource", + [dma_debug_noncoherent] = "noncoherent", }; static const char *dir2name[] = { @@ -993,7 +995,8 @@ static void check_unmap(struct dma_debug_entry *ref) "[mapped as %s] [unmapped as %s]\n", ref->dev_addr, ref->size, type2name[entry->type], type2name[ref->type]); - } else if (entry->type == dma_debug_coherent && + } else if ((entry->type == dma_debug_coherent || + entry->type == dma_debug_noncoherent) && ref->paddr != entry->paddr) { err_printk(ref->dev, entry, "device driver frees " "DMA memory with different CPU address " @@ -1581,6 +1584,49 @@ void debug_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, } } +void debug_dma_alloc_pages(struct device *dev, struct page *page, + size_t size, int direction, + dma_addr_t dma_addr, + unsigned long attrs) +{ + struct dma_debug_entry *entry; + + if (unlikely(dma_debug_disabled())) + return; + + entry = dma_entry_alloc(); + if (!entry) + return; + + entry->type = dma_debug_noncoherent; + entry->dev = dev; + entry->paddr = page_to_phys(page); + entry->size = size; + entry->dev_addr = dma_addr; + entry->direction = direction; + + add_dma_entry(entry, attrs); +} + +void debug_dma_free_pages(struct device *dev, struct page *page, + size_t size, int direction, + dma_addr_t dma_addr) +{ + struct dma_debug_entry ref = { + .type = dma_debug_noncoherent, + .dev = dev, + .paddr = page_to_phys(page), + .dev_addr = dma_addr, + .size = size, + .direction = direction, + }; + + if (unlikely(dma_debug_disabled())) + return; + + check_unmap(&ref); +} + static int __init dma_debug_driver_setup(char *str) { int i; -- cgit v1.2.3 From e9e81d86fee63c6d5757841ab557019ddf73786f Mon Sep 17 00:00:00 2001 From: Leon Romanovsky Date: Tue, 9 Sep 2025 16:27:31 +0300 Subject: dma-debug: refactor to use physical addresses for page mapping Convert the DMA debug infrastructure from page-based to physical address-based mapping as a preparation to rely on physical address for DMA mapping routines. The refactoring renames debug_dma_map_page() to debug_dma_map_phys() and changes its signature to accept a phys_addr_t parameter instead of struct page and offset. Similarly, debug_dma_unmap_page() becomes debug_dma_unmap_phys(). A new dma_debug_phy type is introduced to distinguish physical address mappings from other debug entry types. All callers throughout the codebase are updated to pass physical addresses directly, eliminating the need for page-to-physical conversion in the debug layer. This refactoring eliminates the need to convert between page pointers and physical addresses in the debug layer, making the code more efficient and consistent with the DMA mapping API's physical address focus. Reviewed-by: Jason Gunthorpe Signed-off-by: Leon Romanovsky [mszyprow: added a fixup] Signed-off-by: Marek Szyprowski Link: https://lore.kernel.org/r/56d1a6769b68dfcbf8b26a75a7329aeb8e3c3b6a.1757423202.git.leonro@nvidia.com Link: https://lore.kernel.org/all/20250910052618.GH341237@unreal/ --- Documentation/core-api/dma-api.rst | 4 ++-- include/linux/page-flags.h | 1 + kernel/dma/debug.c | 39 +++++++++++++++++++------------------- kernel/dma/debug.h | 16 +++++++--------- kernel/dma/mapping.c | 10 +++++----- 5 files changed, 35 insertions(+), 35 deletions(-) (limited to 'kernel/dma/debug.c') diff --git a/Documentation/core-api/dma-api.rst b/Documentation/core-api/dma-api.rst index 3087bea715ed..ca75b3541679 100644 --- a/Documentation/core-api/dma-api.rst +++ b/Documentation/core-api/dma-api.rst @@ -761,7 +761,7 @@ example warning message may look like this:: [] find_busiest_group+0x207/0x8a0 [] _spin_lock_irqsave+0x1f/0x50 [] check_unmap+0x203/0x490 - [] debug_dma_unmap_page+0x49/0x50 + [] debug_dma_unmap_phys+0x49/0x50 [] nv_tx_done_optimized+0xc6/0x2c0 [] nv_nic_irq_optimized+0x73/0x2b0 [] handle_IRQ_event+0x34/0x70 @@ -855,7 +855,7 @@ that a driver may be leaking mappings. dma-debug interface debug_dma_mapping_error() to debug drivers that fail to check DMA mapping errors on addresses returned by dma_map_single() and dma_map_page() interfaces. This interface clears a flag set by -debug_dma_map_page() to indicate that dma_mapping_error() has been called by +debug_dma_map_phys() to indicate that dma_mapping_error() has been called by the driver. When driver does unmap, debug_dma_unmap() checks the flag and if this flag is still set, prints warning message that includes call trace that leads up to the unmap. This interface can be called from dma_mapping_error() diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index 8d3fa3a91ce4..2a1f34617802 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -618,6 +618,7 @@ FOLIO_FLAG(dropbehind, FOLIO_HEAD_PAGE) #else PAGEFLAG_FALSE(HighMem, highmem) #endif +#define PhysHighMem(__p) (PageHighMem(phys_to_page(__p))) /* Does kmap_local_folio() only allow access to one page of the folio? */ #ifdef CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP diff --git a/kernel/dma/debug.c b/kernel/dma/debug.c index b82399437db0..b275db9ca6a0 100644 --- a/kernel/dma/debug.c +++ b/kernel/dma/debug.c @@ -40,6 +40,7 @@ enum { dma_debug_coherent, dma_debug_resource, dma_debug_noncoherent, + dma_debug_phy, }; enum map_err_types { @@ -143,6 +144,7 @@ static const char *type2name[] = { [dma_debug_coherent] = "coherent", [dma_debug_resource] = "resource", [dma_debug_noncoherent] = "noncoherent", + [dma_debug_phy] = "phy", }; static const char *dir2name[] = { @@ -1054,17 +1056,16 @@ static void check_unmap(struct dma_debug_entry *ref) dma_entry_free(entry); } -static void check_for_stack(struct device *dev, - struct page *page, size_t offset) +static void check_for_stack(struct device *dev, phys_addr_t phys) { void *addr; struct vm_struct *stack_vm_area = task_stack_vm_area(current); if (!stack_vm_area) { /* Stack is direct-mapped. */ - if (PageHighMem(page)) + if (PhysHighMem(phys)) return; - addr = page_address(page) + offset; + addr = phys_to_virt(phys); if (object_is_on_stack(addr)) err_printk(dev, NULL, "device driver maps memory from stack [addr=%p]\n", addr); } else { @@ -1072,10 +1073,12 @@ static void check_for_stack(struct device *dev, int i; for (i = 0; i < stack_vm_area->nr_pages; i++) { - if (page != stack_vm_area->pages[i]) + if (__phys_to_pfn(phys) != + page_to_pfn(stack_vm_area->pages[i])) continue; - addr = (u8 *)current->stack + i * PAGE_SIZE + offset; + addr = (u8 *)current->stack + i * PAGE_SIZE + + (phys % PAGE_SIZE); err_printk(dev, NULL, "device driver maps memory from stack [probable addr=%p]\n", addr); break; } @@ -1204,9 +1207,8 @@ void debug_dma_map_single(struct device *dev, const void *addr, } EXPORT_SYMBOL(debug_dma_map_single); -void debug_dma_map_page(struct device *dev, struct page *page, size_t offset, - size_t size, int direction, dma_addr_t dma_addr, - unsigned long attrs) +void debug_dma_map_phys(struct device *dev, phys_addr_t phys, size_t size, + int direction, dma_addr_t dma_addr, unsigned long attrs) { struct dma_debug_entry *entry; @@ -1221,19 +1223,18 @@ void debug_dma_map_page(struct device *dev, struct page *page, size_t offset, return; entry->dev = dev; - entry->type = dma_debug_single; - entry->paddr = page_to_phys(page) + offset; + entry->type = dma_debug_phy; + entry->paddr = phys; entry->dev_addr = dma_addr; entry->size = size; entry->direction = direction; entry->map_err_type = MAP_ERR_NOT_CHECKED; - check_for_stack(dev, page, offset); + if (!(attrs & DMA_ATTR_MMIO)) { + check_for_stack(dev, phys); - if (!PageHighMem(page)) { - void *addr = page_address(page) + offset; - - check_for_illegal_area(dev, addr, size); + if (!PhysHighMem(phys)) + check_for_illegal_area(dev, phys_to_virt(phys), size); } add_dma_entry(entry, attrs); @@ -1277,11 +1278,11 @@ void debug_dma_mapping_error(struct device *dev, dma_addr_t dma_addr) } EXPORT_SYMBOL(debug_dma_mapping_error); -void debug_dma_unmap_page(struct device *dev, dma_addr_t dma_addr, +void debug_dma_unmap_phys(struct device *dev, dma_addr_t dma_addr, size_t size, int direction) { struct dma_debug_entry ref = { - .type = dma_debug_single, + .type = dma_debug_phy, .dev = dev, .dev_addr = dma_addr, .size = size, @@ -1305,7 +1306,7 @@ void debug_dma_map_sg(struct device *dev, struct scatterlist *sg, return; for_each_sg(sg, s, nents, i) { - check_for_stack(dev, sg_page(s), s->offset); + check_for_stack(dev, sg_phys(s)); if (!PageHighMem(sg_page(s))) check_for_illegal_area(dev, sg_virt(s), s->length); } diff --git a/kernel/dma/debug.h b/kernel/dma/debug.h index 48757ca13f31..bedae973e725 100644 --- a/kernel/dma/debug.h +++ b/kernel/dma/debug.h @@ -9,12 +9,11 @@ #define _KERNEL_DMA_DEBUG_H #ifdef CONFIG_DMA_API_DEBUG -extern void debug_dma_map_page(struct device *dev, struct page *page, - size_t offset, size_t size, - int direction, dma_addr_t dma_addr, +extern void debug_dma_map_phys(struct device *dev, phys_addr_t phys, + size_t size, int direction, dma_addr_t dma_addr, unsigned long attrs); -extern void debug_dma_unmap_page(struct device *dev, dma_addr_t addr, +extern void debug_dma_unmap_phys(struct device *dev, dma_addr_t addr, size_t size, int direction); extern void debug_dma_map_sg(struct device *dev, struct scatterlist *sg, @@ -62,14 +61,13 @@ extern void debug_dma_free_pages(struct device *dev, struct page *page, size_t size, int direction, dma_addr_t dma_addr); #else /* CONFIG_DMA_API_DEBUG */ -static inline void debug_dma_map_page(struct device *dev, struct page *page, - size_t offset, size_t size, - int direction, dma_addr_t dma_addr, - unsigned long attrs) +static inline void debug_dma_map_phys(struct device *dev, phys_addr_t phys, + size_t size, int direction, + dma_addr_t dma_addr, unsigned long attrs) { } -static inline void debug_dma_unmap_page(struct device *dev, dma_addr_t addr, +static inline void debug_dma_unmap_phys(struct device *dev, dma_addr_t addr, size_t size, int direction) { } diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c index 56de28a3b179..0b7e16c69bf1 100644 --- a/kernel/dma/mapping.c +++ b/kernel/dma/mapping.c @@ -157,6 +157,7 @@ dma_addr_t dma_map_page_attrs(struct device *dev, struct page *page, unsigned long attrs) { const struct dma_map_ops *ops = get_dma_ops(dev); + phys_addr_t phys = page_to_phys(page) + offset; dma_addr_t addr; BUG_ON(!valid_dma_direction(dir)); @@ -165,16 +166,15 @@ dma_addr_t dma_map_page_attrs(struct device *dev, struct page *page, return DMA_MAPPING_ERROR; if (dma_map_direct(dev, ops) || - arch_dma_map_page_direct(dev, page_to_phys(page) + offset + size)) + arch_dma_map_page_direct(dev, phys + size)) addr = dma_direct_map_page(dev, page, offset, size, dir, attrs); else if (use_dma_iommu(dev)) addr = iommu_dma_map_page(dev, page, offset, size, dir, attrs); else addr = ops->map_page(dev, page, offset, size, dir, attrs); kmsan_handle_dma(page, offset, size, dir); - trace_dma_map_page(dev, page_to_phys(page) + offset, addr, size, dir, - attrs); - debug_dma_map_page(dev, page, offset, size, dir, addr, attrs); + trace_dma_map_page(dev, phys, addr, size, dir, attrs); + debug_dma_map_phys(dev, phys, size, dir, addr, attrs); return addr; } @@ -194,7 +194,7 @@ void dma_unmap_page_attrs(struct device *dev, dma_addr_t addr, size_t size, else ops->unmap_page(dev, addr, size, dir, attrs); trace_dma_unmap_page(dev, addr, size, dir, attrs); - debug_dma_unmap_page(dev, addr, size, dir); + debug_dma_unmap_phys(dev, addr, size, dir); } EXPORT_SYMBOL(dma_unmap_page_attrs); -- cgit v1.2.3 From f7326196a781622b33bfbdabb00f5e72b5fb5679 Mon Sep 17 00:00:00 2001 From: Leon Romanovsky Date: Tue, 9 Sep 2025 16:27:39 +0300 Subject: dma-mapping: export new dma_*map_phys() interface Introduce new DMA mapping functions dma_map_phys() and dma_unmap_phys() that operate directly on physical addresses instead of page+offset parameters. This provides a more efficient interface for drivers that already have physical addresses available. The new functions are implemented as the primary mapping layer, with the existing dma_map_page_attrs()/dma_map_resource() and dma_unmap_page_attrs()/dma_unmap_resource() functions converted to simple wrappers around the phys-based implementations. In case dma_map_page_attrs(), the struct page is converted to physical address with help of page_to_phys() function and dma_map_resource() provides physical address as is together with addition of DMA_ATTR_MMIO attribute. The old page-based API is preserved in mapping.c to ensure that existing code won't be affected by changing EXPORT_SYMBOL to EXPORT_SYMBOL_GPL variant for dma_*map_phys(). Reviewed-by: Jason Gunthorpe Reviewed-by: Keith Busch Signed-off-by: Leon Romanovsky Signed-off-by: Marek Szyprowski Link: https://lore.kernel.org/r/54cc52af91777906bbe4a386113437ba0bcfba9c.1757423202.git.leonro@nvidia.com --- drivers/iommu/dma-iommu.c | 14 --------- include/linux/dma-direct.h | 2 -- include/linux/dma-mapping.h | 13 +++++++++ include/linux/iommu-dma.h | 4 --- include/trace/events/dma.h | 2 -- kernel/dma/debug.c | 43 ---------------------------- kernel/dma/debug.h | 21 -------------- kernel/dma/direct.c | 16 ----------- kernel/dma/mapping.c | 69 ++++++++++++++++++++++++--------------------- 9 files changed, 50 insertions(+), 134 deletions(-) (limited to 'kernel/dma/debug.c') diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index 6804aaf034a1..7944a3af4545 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c @@ -1556,20 +1556,6 @@ void iommu_dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents, __iommu_dma_unmap(dev, start, end - start); } -dma_addr_t iommu_dma_map_resource(struct device *dev, phys_addr_t phys, - size_t size, enum dma_data_direction dir, unsigned long attrs) -{ - return __iommu_dma_map(dev, phys, size, - dma_info_to_prot(dir, false, attrs) | IOMMU_MMIO, - dma_get_mask(dev)); -} - -void iommu_dma_unmap_resource(struct device *dev, dma_addr_t handle, - size_t size, enum dma_data_direction dir, unsigned long attrs) -{ - __iommu_dma_unmap(dev, handle, size); -} - static void __iommu_dma_free(struct device *dev, size_t size, void *cpu_addr) { size_t alloc_size = PAGE_ALIGN(size); diff --git a/include/linux/dma-direct.h b/include/linux/dma-direct.h index f3bc0bcd7098..c249912456f9 100644 --- a/include/linux/dma-direct.h +++ b/include/linux/dma-direct.h @@ -149,7 +149,5 @@ void dma_direct_free_pages(struct device *dev, size_t size, struct page *page, dma_addr_t dma_addr, enum dma_data_direction dir); int dma_direct_supported(struct device *dev, u64 mask); -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); #endif /* _LINUX_DMA_DIRECT_H */ diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index 4254fd9bdf5d..8248ff9363ee 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -138,6 +138,10 @@ dma_addr_t dma_map_page_attrs(struct device *dev, struct page *page, unsigned long attrs); void dma_unmap_page_attrs(struct device *dev, dma_addr_t addr, size_t size, enum dma_data_direction dir, unsigned long attrs); +dma_addr_t dma_map_phys(struct device *dev, phys_addr_t phys, size_t size, + enum dma_data_direction dir, unsigned long attrs); +void dma_unmap_phys(struct device *dev, dma_addr_t addr, size_t size, + enum dma_data_direction dir, unsigned long attrs); unsigned int dma_map_sg_attrs(struct device *dev, struct scatterlist *sg, int nents, enum dma_data_direction dir, unsigned long attrs); void dma_unmap_sg_attrs(struct device *dev, struct scatterlist *sg, @@ -192,6 +196,15 @@ static inline void dma_unmap_page_attrs(struct device *dev, dma_addr_t addr, size_t size, enum dma_data_direction dir, unsigned long attrs) { } +static inline dma_addr_t dma_map_phys(struct device *dev, phys_addr_t phys, + size_t size, enum dma_data_direction dir, unsigned long attrs) +{ + return DMA_MAPPING_ERROR; +} +static inline void dma_unmap_phys(struct device *dev, dma_addr_t addr, + size_t size, enum dma_data_direction dir, unsigned long attrs) +{ +} static inline unsigned int dma_map_sg_attrs(struct device *dev, struct scatterlist *sg, int nents, enum dma_data_direction dir, unsigned long attrs) diff --git a/include/linux/iommu-dma.h b/include/linux/iommu-dma.h index 485bdffed988..a92b3ff9b934 100644 --- a/include/linux/iommu-dma.h +++ b/include/linux/iommu-dma.h @@ -42,10 +42,6 @@ size_t iommu_dma_opt_mapping_size(void); size_t iommu_dma_max_mapping_size(struct device *dev); void iommu_dma_free(struct device *dev, size_t size, void *cpu_addr, dma_addr_t handle, unsigned long attrs); -dma_addr_t iommu_dma_map_resource(struct device *dev, phys_addr_t phys, - size_t size, enum dma_data_direction dir, unsigned long attrs); -void iommu_dma_unmap_resource(struct device *dev, dma_addr_t handle, - size_t size, enum dma_data_direction dir, unsigned long attrs); struct sg_table *iommu_dma_alloc_noncontiguous(struct device *dev, size_t size, enum dma_data_direction dir, gfp_t gfp, unsigned long attrs); void iommu_dma_free_noncontiguous(struct device *dev, size_t size, diff --git a/include/trace/events/dma.h b/include/trace/events/dma.h index 84416c7d6bfa..5da59fd8121d 100644 --- a/include/trace/events/dma.h +++ b/include/trace/events/dma.h @@ -73,7 +73,6 @@ DEFINE_EVENT(dma_map, name, \ TP_ARGS(dev, phys_addr, dma_addr, size, dir, attrs)) DEFINE_MAP_EVENT(dma_map_phys); -DEFINE_MAP_EVENT(dma_map_resource); DECLARE_EVENT_CLASS(dma_unmap, TP_PROTO(struct device *dev, dma_addr_t addr, size_t size, @@ -111,7 +110,6 @@ DEFINE_EVENT(dma_unmap, name, \ TP_ARGS(dev, addr, size, dir, attrs)) DEFINE_UNMAP_EVENT(dma_unmap_phys); -DEFINE_UNMAP_EVENT(dma_unmap_resource); DECLARE_EVENT_CLASS(dma_alloc_class, TP_PROTO(struct device *dev, void *virt_addr, dma_addr_t dma_addr, diff --git a/kernel/dma/debug.c b/kernel/dma/debug.c index b275db9ca6a0..1e5c64cb6a42 100644 --- a/kernel/dma/debug.c +++ b/kernel/dma/debug.c @@ -38,7 +38,6 @@ enum { dma_debug_single, dma_debug_sg, dma_debug_coherent, - dma_debug_resource, dma_debug_noncoherent, dma_debug_phy, }; @@ -142,7 +141,6 @@ static const char *type2name[] = { [dma_debug_single] = "single", [dma_debug_sg] = "scatter-gather", [dma_debug_coherent] = "coherent", - [dma_debug_resource] = "resource", [dma_debug_noncoherent] = "noncoherent", [dma_debug_phy] = "phy", }; @@ -1446,47 +1444,6 @@ void debug_dma_free_coherent(struct device *dev, size_t size, check_unmap(&ref); } -void debug_dma_map_resource(struct device *dev, phys_addr_t addr, size_t size, - int direction, dma_addr_t dma_addr, - unsigned long attrs) -{ - struct dma_debug_entry *entry; - - if (unlikely(dma_debug_disabled())) - return; - - entry = dma_entry_alloc(); - if (!entry) - return; - - entry->type = dma_debug_resource; - entry->dev = dev; - entry->paddr = addr; - entry->size = size; - entry->dev_addr = dma_addr; - entry->direction = direction; - entry->map_err_type = MAP_ERR_NOT_CHECKED; - - add_dma_entry(entry, attrs); -} - -void debug_dma_unmap_resource(struct device *dev, dma_addr_t dma_addr, - size_t size, int direction) -{ - struct dma_debug_entry ref = { - .type = dma_debug_resource, - .dev = dev, - .dev_addr = dma_addr, - .size = size, - .direction = direction, - }; - - if (unlikely(dma_debug_disabled())) - return; - - check_unmap(&ref); -} - void debug_dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle, size_t size, int direction) { diff --git a/kernel/dma/debug.h b/kernel/dma/debug.h index bedae973e725..da7be0bddcf6 100644 --- a/kernel/dma/debug.h +++ b/kernel/dma/debug.h @@ -30,14 +30,6 @@ extern void debug_dma_alloc_coherent(struct device *dev, size_t size, extern void debug_dma_free_coherent(struct device *dev, size_t size, void *virt, dma_addr_t addr); -extern void debug_dma_map_resource(struct device *dev, phys_addr_t addr, - size_t size, int direction, - dma_addr_t dma_addr, - unsigned long attrs); - -extern void debug_dma_unmap_resource(struct device *dev, dma_addr_t dma_addr, - size_t size, int direction); - extern void debug_dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle, size_t size, int direction); @@ -95,19 +87,6 @@ static inline void debug_dma_free_coherent(struct device *dev, size_t size, { } -static inline void debug_dma_map_resource(struct device *dev, phys_addr_t addr, - size_t size, int direction, - dma_addr_t dma_addr, - unsigned long attrs) -{ -} - -static inline void debug_dma_unmap_resource(struct device *dev, - dma_addr_t dma_addr, size_t size, - int direction) -{ -} - static inline void debug_dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle, size_t size, int direction) diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c index ba7524f169bc..1f9ee9759426 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -497,22 +497,6 @@ out_unmap: return ret; } -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_capable(dev, dma_addr, size, false))) { - dev_err_once(dev, - "DMA addr %pad+%zu overflow (mask %llx, bus limit %llx).\n", - &dma_addr, size, *dev->dma_mask, dev->bus_dma_limit); - WARN_ON_ONCE(1); - return DMA_MAPPING_ERROR; - } - - return dma_addr; -} - int dma_direct_get_sgtable(struct device *dev, struct sg_table *sgt, void *cpu_addr, dma_addr_t dma_addr, size_t size, unsigned long attrs) diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c index 95eab531e227..fe7472f13b10 100644 --- a/kernel/dma/mapping.c +++ b/kernel/dma/mapping.c @@ -152,12 +152,10 @@ static inline bool dma_map_direct(struct device *dev, return dma_go_direct(dev, *dev->dma_mask, ops); } -dma_addr_t dma_map_page_attrs(struct device *dev, struct page *page, - size_t offset, size_t size, enum dma_data_direction dir, - unsigned long attrs) +dma_addr_t dma_map_phys(struct device *dev, phys_addr_t phys, size_t size, + enum dma_data_direction dir, unsigned long attrs) { const struct dma_map_ops *ops = get_dma_ops(dev); - phys_addr_t phys = page_to_phys(page) + offset; bool is_mmio = attrs & DMA_ATTR_MMIO; dma_addr_t addr; @@ -177,6 +175,9 @@ dma_addr_t dma_map_page_attrs(struct device *dev, struct page *page, addr = ops->map_resource(dev, phys, size, dir, attrs); } else { + struct page *page = phys_to_page(phys); + size_t offset = offset_in_page(phys); + /* * The dma_ops API contract for ops->map_page() requires * kmappable memory, while ops->map_resource() does not. @@ -191,9 +192,26 @@ dma_addr_t dma_map_page_attrs(struct device *dev, struct page *page, return addr; } +EXPORT_SYMBOL_GPL(dma_map_phys); + +dma_addr_t dma_map_page_attrs(struct device *dev, struct page *page, + size_t offset, size_t size, enum dma_data_direction dir, + unsigned long attrs) +{ + phys_addr_t phys = page_to_phys(page) + offset; + + if (unlikely(attrs & DMA_ATTR_MMIO)) + return DMA_MAPPING_ERROR; + + if (IS_ENABLED(CONFIG_DMA_API_DEBUG) && + WARN_ON_ONCE(is_zone_device_page(page))) + return DMA_MAPPING_ERROR; + + return dma_map_phys(dev, phys, size, dir, attrs); +} EXPORT_SYMBOL(dma_map_page_attrs); -void dma_unmap_page_attrs(struct device *dev, dma_addr_t addr, size_t size, +void dma_unmap_phys(struct device *dev, dma_addr_t addr, size_t size, enum dma_data_direction dir, unsigned long attrs) { const struct dma_map_ops *ops = get_dma_ops(dev); @@ -213,6 +231,16 @@ void dma_unmap_page_attrs(struct device *dev, dma_addr_t addr, size_t size, trace_dma_unmap_phys(dev, addr, size, dir, attrs); debug_dma_unmap_phys(dev, addr, size, dir); } +EXPORT_SYMBOL_GPL(dma_unmap_phys); + +void dma_unmap_page_attrs(struct device *dev, dma_addr_t addr, size_t size, + enum dma_data_direction dir, unsigned long attrs) +{ + if (unlikely(attrs & DMA_ATTR_MMIO)) + return; + + dma_unmap_phys(dev, addr, size, dir, attrs); +} EXPORT_SYMBOL(dma_unmap_page_attrs); static int __dma_map_sg_attrs(struct device *dev, struct scatterlist *sg, @@ -338,41 +366,18 @@ EXPORT_SYMBOL(dma_unmap_sg_attrs); dma_addr_t dma_map_resource(struct device *dev, phys_addr_t phys_addr, size_t size, enum dma_data_direction dir, unsigned long attrs) { - const struct dma_map_ops *ops = get_dma_ops(dev); - dma_addr_t addr = DMA_MAPPING_ERROR; - - BUG_ON(!valid_dma_direction(dir)); - - if (WARN_ON_ONCE(!dev->dma_mask)) + if (IS_ENABLED(CONFIG_DMA_API_DEBUG) && + WARN_ON_ONCE(pfn_valid(PHYS_PFN(phys_addr)))) return DMA_MAPPING_ERROR; - if (dma_map_direct(dev, ops)) - addr = dma_direct_map_resource(dev, phys_addr, size, dir, attrs); - else if (use_dma_iommu(dev)) - addr = iommu_dma_map_resource(dev, phys_addr, size, dir, attrs); - else if (ops->map_resource) - addr = ops->map_resource(dev, phys_addr, size, dir, attrs); - - trace_dma_map_resource(dev, phys_addr, addr, size, dir, attrs); - debug_dma_map_resource(dev, phys_addr, size, dir, addr, attrs); - return addr; + return dma_map_phys(dev, phys_addr, size, dir, attrs | DMA_ATTR_MMIO); } EXPORT_SYMBOL(dma_map_resource); void dma_unmap_resource(struct device *dev, dma_addr_t addr, size_t size, enum dma_data_direction dir, unsigned long attrs) { - const struct dma_map_ops *ops = get_dma_ops(dev); - - BUG_ON(!valid_dma_direction(dir)); - if (dma_map_direct(dev, ops)) - ; /* nothing to do: uncached and no swiotlb */ - else if (use_dma_iommu(dev)) - iommu_dma_unmap_resource(dev, addr, size, dir, attrs); - else if (ops->unmap_resource) - ops->unmap_resource(dev, addr, size, dir, attrs); - trace_dma_unmap_resource(dev, addr, size, dir, attrs); - debug_dma_unmap_resource(dev, addr, size, dir); + dma_unmap_phys(dev, addr, size, dir, attrs | DMA_ATTR_MMIO); } EXPORT_SYMBOL(dma_unmap_resource); -- cgit v1.2.3 From 03521c892bb8d0712c23e158ae9bdf8705897df8 Mon Sep 17 00:00:00 2001 From: Marek Szyprowski Date: Thu, 9 Oct 2025 16:15:08 +0200 Subject: dma-debug: don't report false positives with DMA_BOUNCE_UNALIGNED_KMALLOC Commit 370645f41e6e ("dma-mapping: force bouncing if the kmalloc() size is not cache-line-aligned") introduced DMA_BOUNCE_UNALIGNED_KMALLOC feature and permitted architecture specific code configure kmalloc slabs with sizes smaller than the value of dma_get_cache_alignment(). When that feature is enabled, the physical address of some small kmalloc()-ed buffers might be not aligned to the CPU cachelines, thus not really suitable for typical DMA. To properly handle that case a SWIOTLB buffer bouncing is used, so no CPU cache corruption occurs. When that happens, there is no point reporting a false-positive DMA-API warning that the buffer is not properly aligned, as this is not a client driver fault. [m.szyprowski@samsung.com: replace is_swiotlb_allocated() with is_swiotlb_active(), per Catalin] Link: https://lkml.kernel.org/r/20251010173009.3916215-1-m.szyprowski@samsung.com Link: https://lkml.kernel.org/r/20251009141508.2342138-1-m.szyprowski@samsung.com Fixes: 370645f41e6e ("dma-mapping: force bouncing if the kmalloc() size is not cache-line-aligned") Signed-off-by: Marek Szyprowski Reviewed-by: Catalin Marinas Cc: Christoph Hellwig Cc: Inki Dae Cc: Robin Murohy Cc: "Isaac J. Manjarres" Cc: Signed-off-by: Andrew Morton --- kernel/dma/debug.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'kernel/dma/debug.c') diff --git a/kernel/dma/debug.c b/kernel/dma/debug.c index 1e5c64cb6a42..138ede653de4 100644 --- a/kernel/dma/debug.c +++ b/kernel/dma/debug.c @@ -23,6 +23,7 @@ #include #include #include +#include #include #include "debug.h" @@ -594,7 +595,9 @@ static void add_dma_entry(struct dma_debug_entry *entry, unsigned long attrs) if (rc == -ENOMEM) { pr_err_once("cacheline tracking ENOMEM, dma-debug disabled\n"); global_disable = true; - } else if (rc == -EEXIST && !(attrs & DMA_ATTR_SKIP_CPU_SYNC)) { + } else if (rc == -EEXIST && !(attrs & DMA_ATTR_SKIP_CPU_SYNC) && + !(IS_ENABLED(CONFIG_DMA_BOUNCE_UNALIGNED_KMALLOC) && + is_swiotlb_active(entry->dev))) { err_printk(entry->dev, entry, "cacheline tracking EEXIST, overlapping mappings aren't supported\n"); } -- cgit v1.2.3