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 <hch@lst.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>	# m68k
Acked-by: Paul Burton <paul.burton@mips.com>		# mips

10 files changed, 10 insertions, 26 deletions

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 24360211534a..217083caeabd 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -8,7 +8,7 @@ config ARM
 	select ARCH_HAS_DEBUG_VIRTUAL if MMU
 	select ARCH_HAS_DEVMEM_IS_ALLOWED
 	select ARCH_HAS_DMA_COHERENT_TO_PFN if SWIOTLB
-	select ARCH_HAS_DMA_MMAP_PGPROT if SWIOTLB
+	select ARCH_HAS_DMA_WRITE_COMBINE if !ARM_DMA_MEM_BUFFERABLE
 	select ARCH_HAS_ELF_RANDOMIZE
 	select ARCH_HAS_FORTIFY_SOURCE
 	select ARCH_HAS_KEEPINITRD
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index d42557ee69c2..d27b12f61737 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -2402,12 +2402,6 @@ long arch_dma_coherent_to_pfn(struct device *dev, void *cpu_addr,
 	return dma_to_pfn(dev, dma_addr);
 }
 
-pgprot_t arch_dma_mmap_pgprot(struct device *dev, pgprot_t prot,
-		unsigned long attrs)
-{
-	return __get_dma_pgprot(attrs, prot);
-}
-
 void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
 		gfp_t gfp, unsigned long attrs)
 {
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 3adcec05b1f6..dab9dda34206 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -13,7 +13,6 @@ config ARM64
 	select ARCH_HAS_DEBUG_VIRTUAL
 	select ARCH_HAS_DEVMEM_IS_ALLOWED
 	select ARCH_HAS_DMA_COHERENT_TO_PFN
-	select ARCH_HAS_DMA_MMAP_PGPROT
 	select ARCH_HAS_DMA_PREP_COHERENT
 	select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
 	select ARCH_HAS_ELF_RANDOMIZE
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index e09760ece844..6700371227d1 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -435,6 +435,10 @@ static inline pmd_t pmd_mkdevmap(pmd_t pmd)
 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_NORMAL_NC) | PTE_PXN | PTE_UXN)
 #define pgprot_device(prot) \
 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_DEVICE_nGnRE) | PTE_PXN | PTE_UXN)
+#define pgprot_dmacoherent(prot) \
+	__pgprot_modify(prot, PTE_ATTRINDX_MASK, \
+			PTE_ATTRINDX(MT_NORMAL_NC) | PTE_PXN | PTE_UXN)
+
 #define __HAVE_PHYS_MEM_ACCESS_PROT
 struct file;
 extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
index bd2b039f43a6..676efcda51e6 100644
--- a/arch/arm64/mm/dma-mapping.c
+++ b/arch/arm64/mm/dma-mapping.c
@@ -11,12 +11,6 @@
 
 #include <asm/cacheflush.h>
 
-pgprot_t arch_dma_mmap_pgprot(struct device *dev, pgprot_t prot,
-		unsigned long attrs)
-{
-	return pgprot_writecombine(prot);
-}
-
 void arch_sync_dma_for_device(struct device *dev, phys_addr_t paddr,
 		size_t size, enum dma_data_direction dir)
 {
diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig
index c518d695c376..a9e564306d3e 100644
--- a/arch/m68k/Kconfig
+++ b/arch/m68k/Kconfig
@@ -4,7 +4,6 @@ config M68K
 	default y
 	select ARCH_32BIT_OFF_T
 	select ARCH_HAS_BINFMT_FLAT
-	select ARCH_HAS_DMA_MMAP_PGPROT if MMU && !COLDFIRE
 	select ARCH_HAS_DMA_PREP_COHERENT if HAS_DMA && MMU && !COLDFIRE
 	select ARCH_HAS_SYNC_DMA_FOR_DEVICE if HAS_DMA
 	select ARCH_MIGHT_HAVE_PC_PARPORT if ISA
diff --git a/arch/m68k/include/asm/pgtable_mm.h b/arch/m68k/include/asm/pgtable_mm.h
index fe3ddd73a0cc..fde4534b974f 100644
--- a/arch/m68k/include/asm/pgtable_mm.h
+++ b/arch/m68k/include/asm/pgtable_mm.h
@@ -169,6 +169,9 @@ static inline void update_mmu_cache(struct vm_area_struct *vma,
 	    ? (__pgprot((pgprot_val(prot) & _CACHEMASK040) | _PAGE_NOCACHE_S))	\
 	    : (prot)))
 
+pgprot_t pgprot_dmacoherent(pgprot_t prot);
+#define pgprot_dmacoherent(prot)	pgprot_dmacoherent(prot)
+
 #endif /* CONFIG_COLDFIRE */
 #include <asm-generic/pgtable.h>
 #endif /* !__ASSEMBLY__ */
diff --git a/arch/m68k/kernel/dma.c b/arch/m68k/kernel/dma.c
index 30cd59caf037..35064150e348 100644
--- a/arch/m68k/kernel/dma.c
+++ b/arch/m68k/kernel/dma.c
@@ -23,8 +23,7 @@ void arch_dma_prep_coherent(struct page *page, size_t size)
 	cache_push(page_to_phys(page), size);
 }
 
-pgprot_t arch_dma_mmap_pgprot(struct device *dev, pgprot_t prot,
-		unsigned long attrs)
+pgprot_t pgprot_dmacoherent(pgprot_t prot)
 {
 	if (CPU_IS_040_OR_060) {
 		pgprot_val(prot) &= ~_PAGE_CACHE040;
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index d50fafd7bf3a..fc88f68ea1ee 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -1119,7 +1119,7 @@ config DMA_PERDEV_COHERENT
 
 config DMA_NONCOHERENT
 	bool
-	select ARCH_HAS_DMA_MMAP_PGPROT
+	select ARCH_HAS_DMA_WRITE_COMBINE
 	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
 	select ARCH_HAS_UNCACHED_SEGMENT
 	select NEED_DMA_MAP_STATE
diff --git a/arch/mips/mm/dma-noncoherent.c b/arch/mips/mm/dma-noncoherent.c
index ed56c6fa7be2..1d4d57dd9acf 100644
--- a/arch/mips/mm/dma-noncoherent.c
+++ b/arch/mips/mm/dma-noncoherent.c
@@ -65,14 +65,6 @@ long arch_dma_coherent_to_pfn(struct device *dev, void *cpu_addr,
 	return page_to_pfn(virt_to_page(cached_kernel_address(cpu_addr)));
 }
 
-pgprot_t arch_dma_mmap_pgprot(struct device *dev, pgprot_t prot,
-		unsigned long attrs)
-{
-	if (attrs & DMA_ATTR_WRITE_COMBINE)
-		return pgprot_writecombine(prot);
-	return pgprot_noncached(prot);
-}
-
 static inline void dma_sync_virt(void *addr, size_t size,
 		enum dma_data_direction dir)
 {