dma-mapping: consolidate the dma mmap implementations

The only functional differences (modulo a few missing fixes in the arch
code) is that architectures without coherent caches need a hook to
convert a virtual or dma address into a pfn, given that we don't have
the kernel linear mapping available for the otherwise easy virt_to_page
call.  As a side effect we can support mmap of the per-device coherent
area even on architectures not providing the callback, and we make
previous dangerous default methods dma_common_mmap actually save for
non-coherent architectures by rejecting it without the right helper.

In addition to that we need a hook so that some architectures can
override the protection bits when mmaping a dma coherent allocations.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Paul Burton <paul.burton@mips.com> # MIPS parts

4 files changed, 3 insertions, 26 deletions

diff --git a/arch/microblaze/Kconfig b/arch/microblaze/Kconfig
index 0f48ab6a8070..164a4857737a 100644
--- a/arch/microblaze/Kconfig
+++ b/arch/microblaze/Kconfig
@@ -1,6 +1,7 @@
 config MICROBLAZE
 	def_bool y
 	select ARCH_NO_SWAP
+	select ARCH_HAS_DMA_COHERENT_TO_PFN if MMU
 	select ARCH_HAS_GCOV_PROFILE_ALL
 	select ARCH_HAS_SYNC_DMA_FOR_CPU
 	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
@@ -12,7 +13,6 @@ config MICROBLAZE
 	select CLONE_BACKWARDS3
 	select COMMON_CLK
 	select DMA_DIRECT_OPS
-	select DMA_NONCOHERENT_MMAP
 	select GENERIC_ATOMIC64
 	select GENERIC_CLOCKEVENTS
 	select GENERIC_CPU_DEVICES
diff --git a/arch/microblaze/include/asm/pgtable.h b/arch/microblaze/include/asm/pgtable.h
index 7b650ab14fa0..f64ebb9c9a41 100644
--- a/arch/microblaze/include/asm/pgtable.h
+++ b/arch/microblaze/include/asm/pgtable.h
@@ -553,8 +553,6 @@ void __init *early_get_page(void);
 
 extern unsigned long ioremap_bot, ioremap_base;
 
-unsigned long consistent_virt_to_pfn(void *vaddr);
-
 void setup_memory(void);
 #endif /* __ASSEMBLY__ */
 
diff --git a/arch/microblaze/kernel/dma.c b/arch/microblaze/kernel/dma.c
index 71032cf64669..a89c2d4ed5ff 100644
--- a/arch/microblaze/kernel/dma.c
+++ b/arch/microblaze/kernel/dma.c
@@ -42,25 +42,3 @@ void arch_sync_dma_for_cpu(struct device *dev, phys_addr_t paddr,
 {
 	__dma_sync(dev, paddr, size, dir);
 }
-
-int arch_dma_mmap(struct device *dev, struct vm_area_struct *vma,
-		void *cpu_addr, dma_addr_t handle, size_t size,
-		unsigned long attrs)
-{
-#ifdef CONFIG_MMU
-	unsigned long user_count = vma_pages(vma);
-	unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
-	unsigned long off = vma->vm_pgoff;
-	unsigned long pfn;
-
-	if (off >= count || user_count > (count - off))
-		return -ENXIO;
-
-	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
-	pfn = consistent_virt_to_pfn(cpu_addr);
-	return remap_pfn_range(vma, vma->vm_start, pfn + off,
-			       vma->vm_end - vma->vm_start, vma->vm_page_prot);
-#else
-	return -ENXIO;
-#endif
-}
diff --git a/arch/microblaze/mm/consistent.c b/arch/microblaze/mm/consistent.c
index c9a278ac795a..d801cc5f5b95 100644
--- a/arch/microblaze/mm/consistent.c
+++ b/arch/microblaze/mm/consistent.c
@@ -165,7 +165,8 @@ static pte_t *consistent_virt_to_pte(void *vaddr)
 	return pte_offset_kernel(pmd_offset(pgd_offset_k(addr), addr), addr);
 }
 
-unsigned long consistent_virt_to_pfn(void *vaddr)
+long arch_dma_coherent_to_pfn(struct device *dev, void *vaddr,
+		dma_addr_t dma_addr)
 {
 	pte_t *ptep = consistent_virt_to_pte(vaddr);