arm64: mm: Remove assembly DMA cache maintenance wrappers

Remove the __dma_{flush,map,unmap}_area assembly wrappers and call the
appropriate cache maintenance functions directly from the DMA mapping
callbacks.

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20220610151228.4562-3-will@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>

diff --git a/arch/arm64/include/asm/cacheflush.h b/arch/arm64/include/asm/cacheflush.h
index 5a228e203ef997439c251bf393c96b172b0b7d4f..37185e978aeb200893d2d51e447ee38db30a47e1 100644 (file)
--- a/arch/arm64/include/asm/cacheflush.h
+++ b/arch/arm64/include/asm/cacheflush.h
@@ -104,13 +104,6 @@ static inline void flush_icache_range(unsigned long start, unsigned long end)
 }
 #define flush_icache_range flush_icache_range
 
-/*
- * Cache maintenance functions used by the DMA API. No to be used directly.
- */
-extern void __dma_map_area(const void *, size_t, int);
-extern void __dma_unmap_area(const void *, size_t, int);
-extern void __dma_flush_area(const void *, size_t);
-
 /*
  * Copy user data from/to a page which is mapped into a different
  * processes address space.  Really, we want to allow our "user

diff --git a/arch/arm64/mm/cache.S b/arch/arm64/mm/cache.S
index 21c907987080f60d4b25ef70f438332a6c1c24cc..081058d4e4366edbcdfba226f692e1b6c6401c81 100644 (file)
--- a/arch/arm64/mm/cache.S
+++ b/arch/arm64/mm/cache.S
@@ -194,44 +194,3 @@ SYM_FUNC_START(__pi_dcache_clean_pop)
        ret
 SYM_FUNC_END(__pi_dcache_clean_pop)
 SYM_FUNC_ALIAS(dcache_clean_pop, __pi_dcache_clean_pop)
-
-/*
- *     __dma_flush_area(start, size)
- *
- *     clean & invalidate D / U line
- *
- *     - start   - virtual start address of region
- *     - size    - size in question
- */
-SYM_FUNC_START(__pi___dma_flush_area)
-       add     x1, x0, x1
-       dcache_by_line_op civac, sy, x0, x1, x2, x3
-       ret
-SYM_FUNC_END(__pi___dma_flush_area)
-SYM_FUNC_ALIAS(__dma_flush_area, __pi___dma_flush_area)
-
-/*
- *     __dma_map_area(start, size, dir)
- *     - start - kernel virtual start address
- *     - size  - size of region
- *     - dir   - DMA direction
- */
-SYM_FUNC_START(__pi___dma_map_area)
-       add     x1, x0, x1
-       b       __pi_dcache_clean_poc
-SYM_FUNC_END(__pi___dma_map_area)
-SYM_FUNC_ALIAS(__dma_map_area, __pi___dma_map_area)
-
-/*
- *     __dma_unmap_area(start, size, dir)
- *     - start - kernel virtual start address
- *     - size  - size of region
- *     - dir   - DMA direction
- */
-SYM_FUNC_START(__pi___dma_unmap_area)
-       add     x1, x0, x1
-       cmp     w2, #DMA_TO_DEVICE
-       b.ne    __pi_dcache_inval_poc
-       ret
-SYM_FUNC_END(__pi___dma_unmap_area)
-SYM_FUNC_ALIAS(__dma_unmap_area, __pi___dma_unmap_area)

diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
index 6099c81b9322372b27b1c15fdc80d7a5418001a7..599cf81f568514123a3ee5874c2802f082a837a1 100644 (file)
--- a/arch/arm64/mm/dma-mapping.c
+++ b/arch/arm64/mm/dma-mapping.c
@@ -14,20 +14,29 @@
 #include <asm/xen/xen-ops.h>
 
 void arch_sync_dma_for_device(phys_addr_t paddr, size_t size,
-               enum dma_data_direction dir)
+                             enum dma_data_direction dir)
 {
-       __dma_map_area(phys_to_virt(paddr), size, dir);
+       unsigned long start = (unsigned long)phys_to_virt(paddr);
+
+       dcache_clean_poc(start, start + size);
 }
 
 void arch_sync_dma_for_cpu(phys_addr_t paddr, size_t size,
-               enum dma_data_direction dir)
+                          enum dma_data_direction dir)
 {
-       __dma_unmap_area(phys_to_virt(paddr), size, dir);
+       unsigned long start = (unsigned long)phys_to_virt(paddr);
+
+       if (dir == DMA_TO_DEVICE)
+               return;
+
+       dcache_inval_poc(start, start + size);
 }
 
 void arch_dma_prep_coherent(struct page *page, size_t size)
 {
-       __dma_flush_area(page_address(page), size);
+       unsigned long start = (unsigned long)page_address(page);
+
+       dcache_clean_inval_poc(start, start + size);
 }
 
 #ifdef CONFIG_IOMMU_DMA