From 419e2f1838819e954071dfa1d1f820ab3386ada1 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 26 Aug 2019 09:03:44 +0200 Subject: dma-mapping: remove arch_dma_mmap_pgprot arch_dma_mmap_pgprot is used for two things: 1) to override the "normal" uncached page attributes for mapping memory coherent to devices that can't snoop the CPU caches 2) to provide the special DMA_ATTR_WRITE_COMBINE semantics on older arm systems and some mips platforms Replace one with the pgprot_dmacoherent macro that is already provided by arm and much simpler to use, and lift the DMA_ATTR_WRITE_COMBINE handling to common code with an explicit arch opt-in. Signed-off-by: Christoph Hellwig Acked-by: Geert Uytterhoeven # m68k Acked-by: Paul Burton # mips --- kernel/dma/Kconfig | 12 +++++++++--- kernel/dma/mapping.c | 8 +++++--- 2 files changed, 14 insertions(+), 6 deletions(-) (limited to 'kernel/dma') diff --git a/kernel/dma/Kconfig b/kernel/dma/Kconfig index 9decbba255fc..73c5c2b8e824 100644 --- a/kernel/dma/Kconfig +++ b/kernel/dma/Kconfig @@ -20,6 +20,15 @@ config ARCH_HAS_DMA_COHERENCE_H config ARCH_HAS_DMA_SET_MASK bool +# +# Select this option if the architecture needs special handling for +# DMA_ATTR_WRITE_COMBINE. Normally the "uncached" mapping should be what +# people thing of when saying write combine, so very few platforms should +# need to enable this. +# +config ARCH_HAS_DMA_WRITE_COMBINE + bool + config DMA_DECLARE_COHERENT bool @@ -45,9 +54,6 @@ config ARCH_HAS_DMA_PREP_COHERENT config ARCH_HAS_DMA_COHERENT_TO_PFN bool -config ARCH_HAS_DMA_MMAP_PGPROT - bool - config ARCH_HAS_FORCE_DMA_UNENCRYPTED bool diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c index b0038ca3aa92..1b96616c9f20 100644 --- a/kernel/dma/mapping.c +++ b/kernel/dma/mapping.c @@ -161,9 +161,11 @@ pgprot_t dma_pgprot(struct device *dev, pgprot_t prot, unsigned long attrs) (IS_ENABLED(CONFIG_DMA_NONCOHERENT_CACHE_SYNC) && (attrs & DMA_ATTR_NON_CONSISTENT))) return prot; - if (IS_ENABLED(CONFIG_ARCH_HAS_DMA_MMAP_PGPROT)) - return arch_dma_mmap_pgprot(dev, prot, attrs); - return pgprot_noncached(prot); +#ifdef CONFIG_ARCH_HAS_DMA_WRITE_COMBINE + if (attrs & DMA_ATTR_WRITE_COMBINE) + return pgprot_writecombine(prot); +#endif + return pgprot_dmacoherent(prot); } #endif /* CONFIG_MMU */ -- cgit v1.2.3 From 8e3a68fb55e00e0760bd8023883e064f1f93c62d Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Sat, 3 Aug 2019 12:42:15 +0300 Subject: dma-mapping: make dma_atomic_pool_init self-contained The memory allocated for the atomic pool needs to have the same mapping attributes that we use for remapping, so use pgprot_dmacoherent instead of open coding it. Also deduct a suitable zone to allocate the memory from based on the presence of the DMA zones. Signed-off-by: Christoph Hellwig --- kernel/dma/remap.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) (limited to 'kernel/dma') diff --git a/kernel/dma/remap.c b/kernel/dma/remap.c index ffe78f0b2fe4..838123f79639 100644 --- a/kernel/dma/remap.c +++ b/kernel/dma/remap.c @@ -105,7 +105,16 @@ static int __init early_coherent_pool(char *p) } early_param("coherent_pool", early_coherent_pool); -int __init dma_atomic_pool_init(gfp_t gfp, pgprot_t prot) +static gfp_t dma_atomic_pool_gfp(void) +{ + if (IS_ENABLED(CONFIG_ZONE_DMA)) + return GFP_DMA; + if (IS_ENABLED(CONFIG_ZONE_DMA32)) + return GFP_DMA32; + return GFP_KERNEL; +} + +static int __init dma_atomic_pool_init(void) { unsigned int pool_size_order = get_order(atomic_pool_size); unsigned long nr_pages = atomic_pool_size >> PAGE_SHIFT; @@ -117,7 +126,7 @@ int __init dma_atomic_pool_init(gfp_t gfp, pgprot_t prot) page = dma_alloc_from_contiguous(NULL, nr_pages, pool_size_order, false); else - page = alloc_pages(gfp, pool_size_order); + page = alloc_pages(dma_atomic_pool_gfp(), pool_size_order); if (!page) goto out; @@ -128,7 +137,8 @@ int __init dma_atomic_pool_init(gfp_t gfp, pgprot_t prot) goto free_page; addr = dma_common_contiguous_remap(page, atomic_pool_size, VM_USERMAP, - prot, __builtin_return_address(0)); + pgprot_dmacoherent(PAGE_KERNEL), + __builtin_return_address(0)); if (!addr) goto destroy_genpool; @@ -155,6 +165,7 @@ out: atomic_pool_size / 1024); return -ENOMEM; } +postcore_initcall(dma_atomic_pool_init); bool dma_in_atomic_pool(void *start, size_t size) { -- cgit v1.2.3 From 6ba99411b858bd70bae966633561e698cd6de38c Mon Sep 17 00:00:00 2001 From: Yoshihiro Shimoda Date: Wed, 28 Aug 2019 21:35:40 +0900 Subject: dma-mapping: introduce dma_get_merge_boundary() This patch adds a new DMA API "dma_get_merge_boundary". This function returns the DMA merge boundary if the DMA layer can merge the segments. This patch also adds the implementation for a new dma_map_ops pointer. Signed-off-by: Yoshihiro Shimoda Reviewed-by: Simon Horman Signed-off-by: Christoph Hellwig --- kernel/dma/mapping.c | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'kernel/dma') diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c index 1b96616c9f20..72c825c1788e 100644 --- a/kernel/dma/mapping.c +++ b/kernel/dma/mapping.c @@ -407,3 +407,14 @@ size_t dma_max_mapping_size(struct device *dev) return size; } EXPORT_SYMBOL_GPL(dma_max_mapping_size); + +unsigned long dma_get_merge_boundary(struct device *dev) +{ + const struct dma_map_ops *ops = get_dma_ops(dev); + + if (!ops || !ops->get_merge_boundary) + return 0; /* can't merge */ + + return ops->get_merge_boundary(dev); +} +EXPORT_SYMBOL_GPL(dma_get_merge_boundary); -- cgit v1.2.3 From 14451467014b4c8aff6570b44b6d0ee68cd49bc0 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 15 Mar 2019 17:56:43 +0100 Subject: dma-mapping: move the dma_get_sgtable API comments from arm to common code The comments are spot on and should be near the central API, not just near a single implementation. Signed-off-by: Christoph Hellwig --- kernel/dma/mapping.c | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'kernel/dma') diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c index 72c825c1788e..a136932b8e6d 100644 --- a/kernel/dma/mapping.c +++ b/kernel/dma/mapping.c @@ -136,6 +136,17 @@ int dma_common_get_sgtable(struct device *dev, struct sg_table *sgt, return ret; } +/* + * The whole dma_get_sgtable() idea is fundamentally unsafe - it seems + * that the intention is to allow exporting memory allocated via the + * coherent DMA APIs through the dma_buf API, which only accepts a + * scattertable. This presents a couple of problems: + * 1. Not all memory allocated via the coherent DMA APIs is backed by + * a struct page + * 2. Passing coherent DMA memory into the streaming APIs is not allowed + * as we will try to flush the memory through a different alias to that + * actually being used (and the flushes are redundant.) + */ int dma_get_sgtable_attrs(struct device *dev, struct sg_table *sgt, void *cpu_addr, dma_addr_t dma_addr, size_t size, unsigned long attrs) -- cgit v1.2.3 From f9f3232a7d0ab73a33d11f4056c5823010f03d55 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 6 Aug 2019 15:01:50 +0300 Subject: dma-mapping: explicitly wire up ->mmap and ->get_sgtable While the default ->mmap and ->get_sgtable implementations work for the majority of our dma_map_ops impementations they are inherently safe for others that don't use the page allocator or CMA and/or use their own way of remapping not covered by the common code. So remove the defaults if these methods are not wired up, but instead wire up the default implementations for all safe instances. Fixes: e1c7e324539a ("dma-mapping: always provide the dma_map_ops based implementation") Signed-off-by: Christoph Hellwig --- kernel/dma/mapping.c | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) (limited to 'kernel/dma') diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c index a136932b8e6d..c8b4e46407ba 100644 --- a/kernel/dma/mapping.c +++ b/kernel/dma/mapping.c @@ -153,11 +153,12 @@ int dma_get_sgtable_attrs(struct device *dev, struct sg_table *sgt, { const struct dma_map_ops *ops = get_dma_ops(dev); - if (!dma_is_direct(ops) && ops->get_sgtable) - return ops->get_sgtable(dev, sgt, cpu_addr, dma_addr, size, - attrs); - return dma_common_get_sgtable(dev, sgt, cpu_addr, dma_addr, size, - attrs); + if (dma_is_direct(ops)) + return dma_common_get_sgtable(dev, sgt, cpu_addr, dma_addr, + size, attrs); + if (!ops->get_sgtable) + return -ENXIO; + return ops->get_sgtable(dev, sgt, cpu_addr, dma_addr, size, attrs); } EXPORT_SYMBOL(dma_get_sgtable_attrs); @@ -240,9 +241,12 @@ int dma_mmap_attrs(struct device *dev, struct vm_area_struct *vma, { const struct dma_map_ops *ops = get_dma_ops(dev); - if (!dma_is_direct(ops) && ops->mmap) - return ops->mmap(dev, vma, cpu_addr, dma_addr, size, attrs); - return dma_common_mmap(dev, vma, cpu_addr, dma_addr, size, attrs); + if (dma_is_direct(ops)) + return dma_common_mmap(dev, vma, cpu_addr, dma_addr, size, + attrs); + if (!ops->mmap) + return -ENXIO; + return ops->mmap(dev, vma, cpu_addr, dma_addr, size, attrs); } EXPORT_SYMBOL(dma_mmap_attrs); -- cgit v1.2.3 From e29ccc188f3dae1cb66f59e10e01e0f150642a54 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Sat, 3 Aug 2019 13:31:25 +0300 Subject: dma-mapping: add a dma_can_mmap helper Add a helper to check if DMA allocations for a specific device can be mapped to userspace using dma_mmap_*. Signed-off-by: Christoph Hellwig --- kernel/dma/mapping.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) (limited to 'kernel/dma') diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c index c8b4e46407ba..18ba1ac93fc1 100644 --- a/kernel/dma/mapping.c +++ b/kernel/dma/mapping.c @@ -222,6 +222,29 @@ int dma_common_mmap(struct device *dev, struct vm_area_struct *vma, #endif /* !CONFIG_ARCH_NO_COHERENT_DMA_MMAP */ } +/** + * dma_can_mmap - check if a given device supports dma_mmap_* + * @dev: device to check + * + * Returns %true if @dev supports dma_mmap_coherent() and dma_mmap_attrs() to + * map DMA allocations to userspace. + */ +bool dma_can_mmap(struct device *dev) +{ + const struct dma_map_ops *ops = get_dma_ops(dev); + + if (IS_ENABLED(CONFIG_ARCH_NO_COHERENT_DMA_MMAP)) + return false; + + if (dma_is_direct(ops)) { + return dev_is_dma_coherent(dev) || + IS_ENABLED(CONFIG_ARCH_HAS_DMA_COHERENT_TO_PFN); + } + + return ops->mmap != NULL; +} +EXPORT_SYMBOL_GPL(dma_can_mmap); + /** * dma_mmap_attrs - map a coherent DMA allocation into user space * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices -- cgit v1.2.3 From 62fcee9a3bd73e279d3052245a652a918d0c51da Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 6 Aug 2019 15:06:40 +0300 Subject: dma-mapping: remove CONFIG_ARCH_NO_COHERENT_DMA_MMAP CONFIG_ARCH_NO_COHERENT_DMA_MMAP is now functionally identical to !CONFIG_MMU, so remove the separate symbol. The only difference is that arm did not set it for !CONFIG_MMU, but arm uses a separate dma mapping implementation including its own mmap method, which is handled by moving the CONFIG_MMU check in dma_can_mmap so that is only applies to the dma-direct case, just as the other ifdefs for it. Signed-off-by: Christoph Hellwig Acked-by: Geert Uytterhoeven # m68k --- kernel/dma/mapping.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-) (limited to 'kernel/dma') diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c index 18ba1ac93fc1..285de5fbc8e9 100644 --- a/kernel/dma/mapping.c +++ b/kernel/dma/mapping.c @@ -188,7 +188,7 @@ int dma_common_mmap(struct device *dev, struct vm_area_struct *vma, void *cpu_addr, dma_addr_t dma_addr, size_t size, unsigned long attrs) { -#ifndef CONFIG_ARCH_NO_COHERENT_DMA_MMAP +#ifdef CONFIG_MMU unsigned long user_count = vma_pages(vma); unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT; unsigned long off = vma->vm_pgoff; @@ -219,7 +219,7 @@ int dma_common_mmap(struct device *dev, struct vm_area_struct *vma, user_count << PAGE_SHIFT, vma->vm_page_prot); #else return -ENXIO; -#endif /* !CONFIG_ARCH_NO_COHERENT_DMA_MMAP */ +#endif /* CONFIG_MMU */ } /** @@ -233,12 +233,10 @@ bool dma_can_mmap(struct device *dev) { const struct dma_map_ops *ops = get_dma_ops(dev); - if (IS_ENABLED(CONFIG_ARCH_NO_COHERENT_DMA_MMAP)) - return false; - if (dma_is_direct(ops)) { - return dev_is_dma_coherent(dev) || - IS_ENABLED(CONFIG_ARCH_HAS_DMA_COHERENT_TO_PFN); + return IS_ENABLED(CONFIG_MMU) && + (dev_is_dma_coherent(dev) || + IS_ENABLED(CONFIG_ARCH_HAS_DMA_COHERENT_TO_PFN)); } return ops->mmap != NULL; -- cgit v1.2.3 From 1fa0682448acd5198f79c1d28ee1292a27ae406d Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 30 Aug 2019 08:46:57 +0200 Subject: dma-mapping: remove dma_release_declared_memory This function is entirely unused given that declared memory is generally provided by platform setup code. Signed-off-by: Christoph Hellwig --- kernel/dma/coherent.c | 11 ----------- 1 file changed, 11 deletions(-) (limited to 'kernel/dma') diff --git a/kernel/dma/coherent.c b/kernel/dma/coherent.c index 29fd6590dc1e..7271cda86a37 100644 --- a/kernel/dma/coherent.c +++ b/kernel/dma/coherent.c @@ -124,17 +124,6 @@ int dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr, } EXPORT_SYMBOL(dma_declare_coherent_memory); -void dma_release_declared_memory(struct device *dev) -{ - struct dma_coherent_mem *mem = dev->dma_mem; - - if (!mem) - return; - dma_release_coherent_memory(mem); - dev->dma_mem = NULL; -} -EXPORT_SYMBOL(dma_release_declared_memory); - static void *__dma_alloc_from_coherent(struct dma_coherent_mem *mem, ssize_t size, dma_addr_t *dma_handle) { -- cgit v1.2.3 From 7a01ee42209c00e551c7cfb581be7a207a376f00 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 30 Aug 2019 08:40:33 +0200 Subject: dma-mapping: remove the dma_mmap_from_dev_coherent export dma_mmap_from_dev_coherent is only used by dma_map_ops instances, none of which is modular. Signed-off-by: Christoph Hellwig --- kernel/dma/coherent.c | 1 - 1 file changed, 1 deletion(-) (limited to 'kernel/dma') diff --git a/kernel/dma/coherent.c b/kernel/dma/coherent.c index 7271cda86a37..7cafe1affdc9 100644 --- a/kernel/dma/coherent.c +++ b/kernel/dma/coherent.c @@ -277,7 +277,6 @@ int dma_mmap_from_dev_coherent(struct device *dev, struct vm_area_struct *vma, return __dma_mmap_from_coherent(mem, vma, vaddr, size, ret); } -EXPORT_SYMBOL(dma_mmap_from_dev_coherent); int dma_mmap_from_global_coherent(struct vm_area_struct *vma, void *vaddr, size_t size, int *ret) -- cgit v1.2.3 From d9295532d5725e5926d76470acdfd239c8d2aad3 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 30 Aug 2019 08:48:27 +0200 Subject: dma-mapping: remove the dma_declare_coherent_memory export dma_declare_coherent_memory is something that the platform setup code (which pretty much means the device tree these days) need to do so that drivers can use the memory as declared by the platform. Drivers themselves have no business calling this function. Signed-off-by: Christoph Hellwig --- kernel/dma/coherent.c | 1 - 1 file changed, 1 deletion(-) (limited to 'kernel/dma') diff --git a/kernel/dma/coherent.c b/kernel/dma/coherent.c index 7cafe1affdc9..545e3869b0e3 100644 --- a/kernel/dma/coherent.c +++ b/kernel/dma/coherent.c @@ -122,7 +122,6 @@ int dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr, dma_release_coherent_memory(mem); return ret; } -EXPORT_SYMBOL(dma_declare_coherent_memory); static void *__dma_alloc_from_coherent(struct dma_coherent_mem *mem, ssize_t size, dma_addr_t *dma_handle) -- cgit v1.2.3 From 249baa54790171438524ba97e8e0485dd6aa2762 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 6 Aug 2019 15:01:38 +0300 Subject: dma-mapping: provide a better default ->get_required_mask Most dma_map_ops instances are IOMMUs that work perfectly fine in 32-bits of IOVA space, and the generic direct mapping code already provides its own routines that is intelligent based on the amount of memory actually present. Wire up the dma-direct routine for the ARM direct mapping code as well, and otherwise default to the constant 32-bit mask. This way we only need to override it for the occasional odd IOMMU that requires 64-bit IOVA support, or IOMMU drivers that are more efficient if they can fall back to the direct mapping. Signed-off-by: Christoph Hellwig --- kernel/dma/mapping.c | 30 ++++++++++-------------------- 1 file changed, 10 insertions(+), 20 deletions(-) (limited to 'kernel/dma') diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c index 285de5fbc8e9..64a3d294f4b4 100644 --- a/kernel/dma/mapping.c +++ b/kernel/dma/mapping.c @@ -271,25 +271,6 @@ int dma_mmap_attrs(struct device *dev, struct vm_area_struct *vma, } EXPORT_SYMBOL(dma_mmap_attrs); -static u64 dma_default_get_required_mask(struct device *dev) -{ - u32 low_totalram = ((max_pfn - 1) << PAGE_SHIFT); - u32 high_totalram = ((max_pfn - 1) >> (32 - PAGE_SHIFT)); - u64 mask; - - if (!high_totalram) { - /* convert to mask just covering totalram */ - low_totalram = (1 << (fls(low_totalram) - 1)); - low_totalram += low_totalram - 1; - mask = low_totalram; - } else { - high_totalram = (1 << (fls(high_totalram) - 1)); - high_totalram += high_totalram - 1; - mask = (((u64)high_totalram) << 32) + 0xffffffff; - } - return mask; -} - u64 dma_get_required_mask(struct device *dev) { const struct dma_map_ops *ops = get_dma_ops(dev); @@ -298,7 +279,16 @@ u64 dma_get_required_mask(struct device *dev) return dma_direct_get_required_mask(dev); if (ops->get_required_mask) return ops->get_required_mask(dev); - return dma_default_get_required_mask(dev); + + /* + * We require every DMA ops implementation to at least support a 32-bit + * DMA mask (and use bounce buffering if that isn't supported in + * hardware). As the direct mapping code has its own routine to + * actually report an optimal mask we default to 32-bit here as that + * is the right thing for most IOMMUs, and at least not actively + * harmful in general. + */ + return DMA_BIT_MASK(32); } EXPORT_SYMBOL_GPL(dma_get_required_mask); -- cgit v1.2.3 From 512317401f6a337e617ec284d20dec5fa3a951ec Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 30 Aug 2019 08:51:01 +0200 Subject: dma-mapping: always use VM_DMA_COHERENT for generic DMA remap Currently the generic dma remap allocator gets a vm_flags passed by the caller that is a little confusing. We just introduced a generic vmalloc-level flag to identify the dma coherent allocations, so use that everywhere and remove the now pointless argument. Signed-off-by: Christoph Hellwig --- kernel/dma/remap.c | 23 ++++++++++------------- 1 file changed, 10 insertions(+), 13 deletions(-) (limited to 'kernel/dma') diff --git a/kernel/dma/remap.c b/kernel/dma/remap.c index 838123f79639..f6b90521a7e4 100644 --- a/kernel/dma/remap.c +++ b/kernel/dma/remap.c @@ -12,12 +12,11 @@ #include static struct vm_struct *__dma_common_pages_remap(struct page **pages, - size_t size, unsigned long vm_flags, pgprot_t prot, - const void *caller) + size_t size, pgprot_t prot, const void *caller) { struct vm_struct *area; - area = get_vm_area_caller(size, vm_flags, caller); + area = get_vm_area_caller(size, VM_DMA_COHERENT, caller); if (!area) return NULL; @@ -34,12 +33,11 @@ static struct vm_struct *__dma_common_pages_remap(struct page **pages, * Cannot be used in non-sleeping contexts */ void *dma_common_pages_remap(struct page **pages, size_t size, - unsigned long vm_flags, pgprot_t prot, - const void *caller) + pgprot_t prot, const void *caller) { struct vm_struct *area; - area = __dma_common_pages_remap(pages, size, vm_flags, prot, caller); + area = __dma_common_pages_remap(pages, size, prot, caller); if (!area) return NULL; @@ -53,7 +51,6 @@ void *dma_common_pages_remap(struct page **pages, size_t size, * Cannot be used in non-sleeping contexts */ void *dma_common_contiguous_remap(struct page *page, size_t size, - unsigned long vm_flags, pgprot_t prot, const void *caller) { int i; @@ -67,7 +64,7 @@ void *dma_common_contiguous_remap(struct page *page, size_t size, for (i = 0; i < (size >> PAGE_SHIFT); i++) pages[i] = nth_page(page, i); - area = __dma_common_pages_remap(pages, size, vm_flags, prot, caller); + area = __dma_common_pages_remap(pages, size, prot, caller); kfree(pages); @@ -79,11 +76,11 @@ void *dma_common_contiguous_remap(struct page *page, size_t size, /* * Unmaps a range previously mapped by dma_common_*_remap */ -void dma_common_free_remap(void *cpu_addr, size_t size, unsigned long vm_flags) +void dma_common_free_remap(void *cpu_addr, size_t size) { struct vm_struct *area = find_vm_area(cpu_addr); - if (!area || (area->flags & vm_flags) != vm_flags) { + if (!area || area->flags != VM_DMA_COHERENT) { WARN(1, "trying to free invalid coherent area: %p\n", cpu_addr); return; } @@ -136,7 +133,7 @@ static int __init dma_atomic_pool_init(void) if (!atomic_pool) goto free_page; - addr = dma_common_contiguous_remap(page, atomic_pool_size, VM_USERMAP, + addr = dma_common_contiguous_remap(page, atomic_pool_size, pgprot_dmacoherent(PAGE_KERNEL), __builtin_return_address(0)); if (!addr) @@ -153,7 +150,7 @@ static int __init dma_atomic_pool_init(void) return 0; remove_mapping: - dma_common_free_remap(addr, atomic_pool_size, VM_USERMAP); + dma_common_free_remap(addr, atomic_pool_size); destroy_genpool: gen_pool_destroy(atomic_pool); atomic_pool = NULL; @@ -228,7 +225,7 @@ void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, arch_dma_prep_coherent(page, size); /* create a coherent mapping */ - ret = dma_common_contiguous_remap(page, size, VM_USERMAP, + ret = dma_common_contiguous_remap(page, size, dma_pgprot(dev, PAGE_KERNEL, attrs), __builtin_return_address(0)); if (!ret) { -- cgit v1.2.3 From 5cf4537975bbd5691b9ddd015d540bb92f61e322 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 3 Jun 2019 09:14:31 +0200 Subject: dma-mapping: introduce a dma_common_find_pages helper A helper to find the backing page array based on a virtual address. This also ensures we do the same vm_flags check everywhere instead of slightly different or missing ones in a few places. Signed-off-by: Christoph Hellwig --- kernel/dma/remap.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) (limited to 'kernel/dma') diff --git a/kernel/dma/remap.c b/kernel/dma/remap.c index f6b90521a7e4..ca4e5d44b571 100644 --- a/kernel/dma/remap.c +++ b/kernel/dma/remap.c @@ -11,6 +11,15 @@ #include #include +struct page **dma_common_find_pages(void *cpu_addr) +{ + struct vm_struct *area = find_vm_area(cpu_addr); + + if (!area || area->flags != VM_DMA_COHERENT) + return NULL; + return area->pages; +} + static struct vm_struct *__dma_common_pages_remap(struct page **pages, size_t size, pgprot_t prot, const void *caller) { @@ -78,9 +87,9 @@ void *dma_common_contiguous_remap(struct page *page, size_t size, */ void dma_common_free_remap(void *cpu_addr, size_t size) { - struct vm_struct *area = find_vm_area(cpu_addr); + struct page **pages = dma_common_find_pages(cpu_addr); - if (!area || area->flags != VM_DMA_COHERENT) { + if (!pages) { WARN(1, "trying to free invalid coherent area: %p\n", cpu_addr); return; } -- cgit v1.2.3