From: Nicolas Saenz Julienne nsaenzjulienne@suse.de
upstream 8b5369ea580964dbc982781bfb9fb93459fc5e8d commit.
Some architectures, notably ARM, are interested in tweaking this depending on their runtime DMA addressing limitations.
Acked-by: Christoph Hellwig hch@lst.de Signed-off-by: Nicolas Saenz Julienne nsaenzjulienne@suse.de Signed-off-by: Catalin Marinas catalin.marinas@arm.com Change-Id: I890f2bfbbf5758e3868acddd7bba6f655ec2b357 Signed-off-by: Peter Gonda pgonda@google.com --- arch/arm64/mm/init.c | 9 ++++++++- arch/powerpc/include/asm/page.h | 9 --------- arch/powerpc/mm/mem.c | 20 +++++++++++++++----- arch/s390/include/asm/page.h | 2 -- arch/s390/mm/init.c | 1 + include/linux/dma-direct.h | 2 ++ kernel/dma/direct.c | 13 ++++++------- 7 files changed, 32 insertions(+), 24 deletions(-)
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index 45c00a54909c..214cedc9271c 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -20,6 +20,7 @@ #include <linux/sort.h> #include <linux/of.h> #include <linux/of_fdt.h> +#include <linux/dma-direct.h> #include <linux/dma-mapping.h> #include <linux/dma-contiguous.h> #include <linux/efi.h> @@ -41,6 +42,8 @@ #include <asm/tlb.h> #include <asm/alternative.h>
+#define ARM64_ZONE_DMA_BITS 30 + /* * We need to be able to catch inadvertent references to memstart_addr * that occur (potentially in generic code) before arm64_memblock_init() @@ -418,7 +421,11 @@ void __init arm64_memblock_init(void)
early_init_fdt_scan_reserved_mem();
- /* 4GB maximum for 32-bit only capable devices */ + if (IS_ENABLED(CONFIG_ZONE_DMA)) { + zone_dma_bits = ARM64_ZONE_DMA_BITS; + arm64_dma_phys_limit = max_zone_phys(ARM64_ZONE_DMA_BITS); + } + if (IS_ENABLED(CONFIG_ZONE_DMA32)) arm64_dma_phys_limit = max_zone_dma_phys(); else diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h index 6ba5adb96a3b..d568ce08e3b2 100644 --- a/arch/powerpc/include/asm/page.h +++ b/arch/powerpc/include/asm/page.h @@ -334,13 +334,4 @@ struct vm_area_struct; #endif /* __ASSEMBLY__ */ #include <asm/slice.h>
-/* - * Allow 30-bit DMA for very limited Broadcom wifi chips on many powerbooks. - */ -#ifdef CONFIG_PPC32 -#define ARCH_ZONE_DMA_BITS 30 -#else -#define ARCH_ZONE_DMA_BITS 31 -#endif - #endif /* _ASM_POWERPC_PAGE_H */ diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c index 96ca90ce0264..3b99b6b67fb5 100644 --- a/arch/powerpc/mm/mem.c +++ b/arch/powerpc/mm/mem.c @@ -31,6 +31,7 @@ #include <linux/slab.h> #include <linux/vmalloc.h> #include <linux/memremap.h> +#include <linux/dma-direct.h>
#include <asm/pgalloc.h> #include <asm/prom.h> @@ -223,10 +224,10 @@ static int __init mark_nonram_nosave(void) * everything else. GFP_DMA32 page allocations automatically fall back to * ZONE_DMA. * - * By using 31-bit unconditionally, we can exploit ARCH_ZONE_DMA_BITS to - * inform the generic DMA mapping code. 32-bit only devices (if not handled - * by an IOMMU anyway) will take a first dip into ZONE_NORMAL and get - * otherwise served by ZONE_DMA. + * By using 31-bit unconditionally, we can exploit zone_dma_bits to inform the + * generic DMA mapping code. 32-bit only devices (if not handled by an IOMMU + * anyway) will take a first dip into ZONE_NORMAL and get otherwise served by + * ZONE_DMA. */ static unsigned long max_zone_pfns[MAX_NR_ZONES];
@@ -259,9 +260,18 @@ void __init paging_init(void) printk(KERN_DEBUG "Memory hole size: %ldMB\n", (long int)((top_of_ram - total_ram) >> 20));
+ /* + * Allow 30-bit DMA for very limited Broadcom wifi chips on many + * powerbooks. + */ + if (IS_ENABLED(CONFIG_PPC32)) + zone_dma_bits = 30; + else + zone_dma_bits = 31; + #ifdef CONFIG_ZONE_DMA max_zone_pfns[ZONE_DMA] = min(max_low_pfn, - 1UL << (ARCH_ZONE_DMA_BITS - PAGE_SHIFT)); + 1UL << (zone_dma_bits - PAGE_SHIFT)); #endif max_zone_pfns[ZONE_NORMAL] = max_low_pfn; #ifdef CONFIG_HIGHMEM diff --git a/arch/s390/include/asm/page.h b/arch/s390/include/asm/page.h index e399102367af..1019efd85b9d 100644 --- a/arch/s390/include/asm/page.h +++ b/arch/s390/include/asm/page.h @@ -179,8 +179,6 @@ static inline int devmem_is_allowed(unsigned long pfn) #define VM_DATA_DEFAULT_FLAGS (VM_READ | VM_WRITE | \ VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
-#define ARCH_ZONE_DMA_BITS 31 - #include <asm-generic/memory_model.h> #include <asm-generic/getorder.h>
diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c index c1d96e588152..ac44bd76db4b 100644 --- a/arch/s390/mm/init.c +++ b/arch/s390/mm/init.c @@ -118,6 +118,7 @@ void __init paging_init(void)
sparse_memory_present_with_active_regions(MAX_NUMNODES); sparse_init(); + zone_dma_bits = 31; memset(max_zone_pfns, 0, sizeof(max_zone_pfns)); max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS); max_zone_pfns[ZONE_NORMAL] = max_low_pfn; diff --git a/include/linux/dma-direct.h b/include/linux/dma-direct.h index 6db863c3eb93..f3b276242f2d 100644 --- a/include/linux/dma-direct.h +++ b/include/linux/dma-direct.h @@ -6,6 +6,8 @@ #include <linux/memblock.h> /* for min_low_pfn */ #include <linux/mem_encrypt.h>
+extern unsigned int zone_dma_bits; + static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr);
#ifdef CONFIG_ARCH_HAS_PHYS_TO_DMA diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c index 71be82b07743..2af418b4b6f9 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -17,12 +17,11 @@ #include <linux/swiotlb.h>
/* - * Most architectures use ZONE_DMA for the first 16 Megabytes, but - * some use it for entirely different regions: + * Most architectures use ZONE_DMA for the first 16 Megabytes, but some use it + * it for entirely different regions. In that case the arch code needs to + * override the variable below for dma-direct to work properly. */ -#ifndef ARCH_ZONE_DMA_BITS -#define ARCH_ZONE_DMA_BITS 24 -#endif +unsigned int zone_dma_bits __ro_after_init = 24;
static void report_addr(struct device *dev, dma_addr_t dma_addr, size_t size) { @@ -77,7 +76,7 @@ gfp_t dma_direct_optimal_gfp_mask(struct device *dev, u64 dma_mask, * Note that GFP_DMA32 and GFP_DMA are no ops without the corresponding * zones. */ - if (*phys_mask <= DMA_BIT_MASK(ARCH_ZONE_DMA_BITS)) + if (*phys_mask <= DMA_BIT_MASK(zone_dma_bits)) return GFP_DMA; if (*phys_mask <= DMA_BIT_MASK(32)) return GFP_DMA32; @@ -547,7 +546,7 @@ int dma_direct_supported(struct device *dev, u64 mask) u64 min_mask;
if (IS_ENABLED(CONFIG_ZONE_DMA)) - min_mask = DMA_BIT_MASK(ARCH_ZONE_DMA_BITS); + min_mask = DMA_BIT_MASK(zone_dma_bits); else min_mask = DMA_BIT_MASK(32);