From 6e8266e3333bd01700decf9866725e254d84f21a Mon Sep 17 00:00:00 2001 From: Carlo Caione Date: Mon, 9 Feb 2015 10:38:35 +0100 Subject: [PATCH] ARM: 8304/1: Respect NO_KERNEL_MAPPING when we don't have an IOMMU Even without an iommu, NO_KERNEL_MAPPING is still convenient to save on kernel address space in places where we don't need a kernel mapping. Implement support for it in the two places where we're creating an expensive mapping. __alloc_from_pool uses an internal pool from which we already have virtual addresses, so it's not relevant, and __alloc_simple_buffer uses alloc_pages, which will always return a lowmem page, which is already mapped into kernel space, so we can't prevent a mapping for it in that case. Signed-off-by: Jasper St. Pierre Signed-off-by: Carlo Caione Reviewed-by: Rob Clark Reviewed-by: Daniel Drake Acked-by: Marek Szyprowski Signed-off-by: Russell King --- arch/arm/mm/dma-mapping.c | 67 ++++++++++++++++++++++++--------------- 1 file changed, 41 insertions(+), 26 deletions(-) diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index 170a116d1b29..713761643e38 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -289,11 +289,11 @@ static void __dma_free_buffer(struct page *page, size_t size) static void *__alloc_from_contiguous(struct device *dev, size_t size, pgprot_t prot, struct page **ret_page, - const void *caller); + const void *caller, bool want_vaddr); static void *__alloc_remap_buffer(struct device *dev, size_t size, gfp_t gfp, pgprot_t prot, struct page **ret_page, - const void *caller); + const void *caller, bool want_vaddr); static void * __dma_alloc_remap(struct page *page, size_t size, gfp_t gfp, pgprot_t prot, @@ -357,10 +357,10 @@ static int __init atomic_pool_init(void) if (dev_get_cma_area(NULL)) ptr = __alloc_from_contiguous(NULL, atomic_pool_size, prot, - &page, atomic_pool_init); + &page, atomic_pool_init, true); else ptr = __alloc_remap_buffer(NULL, atomic_pool_size, gfp, prot, - &page, atomic_pool_init); + &page, atomic_pool_init, true); if (ptr) { int ret; @@ -467,13 +467,15 @@ static void __dma_remap(struct page *page, size_t size, pgprot_t prot) static void *__alloc_remap_buffer(struct device *dev, size_t size, gfp_t gfp, pgprot_t prot, struct page **ret_page, - const void *caller) + const void *caller, bool want_vaddr) { struct page *page; - void *ptr; + void *ptr = NULL; page = __dma_alloc_buffer(dev, size, gfp); if (!page) return NULL; + if (!want_vaddr) + goto out; ptr = __dma_alloc_remap(page, size, gfp, prot, caller); if (!ptr) { @@ -481,6 +483,7 @@ static void *__alloc_remap_buffer(struct device *dev, size_t size, gfp_t gfp, return NULL; } + out: *ret_page = page; return ptr; } @@ -523,12 +526,12 @@ static int __free_from_pool(void *start, size_t size) static void *__alloc_from_contiguous(struct device *dev, size_t size, pgprot_t prot, struct page **ret_page, - const void *caller) + const void *caller, bool want_vaddr) { unsigned long order = get_order(size); size_t count = size >> PAGE_SHIFT; struct page *page; - void *ptr; + void *ptr = NULL; page = dma_alloc_from_contiguous(dev, count, order); if (!page) @@ -536,6 +539,9 @@ static void *__alloc_from_contiguous(struct device *dev, size_t size, __dma_clear_buffer(page, size); + if (!want_vaddr) + goto out; + if (PageHighMem(page)) { ptr = __dma_alloc_remap(page, size, GFP_KERNEL, prot, caller); if (!ptr) { @@ -546,17 +552,21 @@ static void *__alloc_from_contiguous(struct device *dev, size_t size, __dma_remap(page, size, prot); ptr = page_address(page); } + + out: *ret_page = page; return ptr; } static void __free_from_contiguous(struct device *dev, struct page *page, - void *cpu_addr, size_t size) + void *cpu_addr, size_t size, bool want_vaddr) { - if (PageHighMem(page)) - __dma_free_remap(cpu_addr, size); - else - __dma_remap(page, size, PAGE_KERNEL); + if (want_vaddr) { + if (PageHighMem(page)) + __dma_free_remap(cpu_addr, size); + else + __dma_remap(page, size, PAGE_KERNEL); + } dma_release_from_contiguous(dev, page, size >> PAGE_SHIFT); } @@ -574,12 +584,12 @@ static inline pgprot_t __get_dma_pgprot(struct dma_attrs *attrs, pgprot_t prot) #define nommu() 1 -#define __get_dma_pgprot(attrs, prot) __pgprot(0) -#define __alloc_remap_buffer(dev, size, gfp, prot, ret, c) NULL +#define __get_dma_pgprot(attrs, prot) __pgprot(0) +#define __alloc_remap_buffer(dev, size, gfp, prot, ret, c, wv) NULL #define __alloc_from_pool(size, ret_page) NULL -#define __alloc_from_contiguous(dev, size, prot, ret, c) NULL +#define __alloc_from_contiguous(dev, size, prot, ret, c, wv) NULL #define __free_from_pool(cpu_addr, size) 0 -#define __free_from_contiguous(dev, page, cpu_addr, size) do { } while (0) +#define __free_from_contiguous(dev, page, cpu_addr, size, wv) do { } while (0) #define __dma_free_remap(cpu_addr, size) do { } while (0) #endif /* CONFIG_MMU */ @@ -599,11 +609,13 @@ static void *__alloc_simple_buffer(struct device *dev, size_t size, gfp_t gfp, static void *__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, - gfp_t gfp, pgprot_t prot, bool is_coherent, const void *caller) + gfp_t gfp, pgprot_t prot, bool is_coherent, + struct dma_attrs *attrs, const void *caller) { u64 mask = get_coherent_dma_mask(dev); struct page *page = NULL; void *addr; + bool want_vaddr; #ifdef CONFIG_DMA_API_DEBUG u64 limit = (mask + 1) & ~mask; @@ -631,20 +643,21 @@ static void *__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, *handle = DMA_ERROR_CODE; size = PAGE_ALIGN(size); + want_vaddr = !dma_get_attr(DMA_ATTR_NO_KERNEL_MAPPING, attrs); if (is_coherent || nommu()) addr = __alloc_simple_buffer(dev, size, gfp, &page); else if (!(gfp & __GFP_WAIT)) addr = __alloc_from_pool(size, &page); else if (!dev_get_cma_area(dev)) - addr = __alloc_remap_buffer(dev, size, gfp, prot, &page, caller); + addr = __alloc_remap_buffer(dev, size, gfp, prot, &page, caller, want_vaddr); else - addr = __alloc_from_contiguous(dev, size, prot, &page, caller); + addr = __alloc_from_contiguous(dev, size, prot, &page, caller, want_vaddr); - if (addr) + if (page) *handle = pfn_to_dma(dev, page_to_pfn(page)); - return addr; + return want_vaddr ? addr : page; } /* @@ -661,7 +674,7 @@ void *arm_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, return memory; return __dma_alloc(dev, size, handle, gfp, prot, false, - __builtin_return_address(0)); + attrs, __builtin_return_address(0)); } static void *arm_coherent_dma_alloc(struct device *dev, size_t size, @@ -674,7 +687,7 @@ static void *arm_coherent_dma_alloc(struct device *dev, size_t size, return memory; return __dma_alloc(dev, size, handle, gfp, prot, true, - __builtin_return_address(0)); + attrs, __builtin_return_address(0)); } /* @@ -715,6 +728,7 @@ static void __arm_dma_free(struct device *dev, size_t size, void *cpu_addr, bool is_coherent) { struct page *page = pfn_to_page(dma_to_pfn(dev, handle)); + bool want_vaddr = !dma_get_attr(DMA_ATTR_NO_KERNEL_MAPPING, attrs); if (dma_release_from_coherent(dev, get_order(size), cpu_addr)) return; @@ -726,14 +740,15 @@ static void __arm_dma_free(struct device *dev, size_t size, void *cpu_addr, } else if (__free_from_pool(cpu_addr, size)) { return; } else if (!dev_get_cma_area(dev)) { - __dma_free_remap(cpu_addr, size); + if (want_vaddr) + __dma_free_remap(cpu_addr, size); __dma_free_buffer(page, size); } else { /* * Non-atomic allocations cannot be freed with IRQs disabled */ WARN_ON(irqs_disabled()); - __free_from_contiguous(dev, page, cpu_addr, size); + __free_from_contiguous(dev, page, cpu_addr, size, want_vaddr); } } -- 2.34.1