[PATCH v2] arm64: mm: convert __dma_* routines to use start, size

From: Kwangwoo Lee
Date: Tue Jul 26 2016 - 03:36:13 EST


v2)
change __dma_* routine names using the terminoloy guidance:
area: takes a start and size
range: takes a start and end
use __dma_flush_area() instead of __dma_flush_range() in dma-mapping.c

v1)
__dma_* routines have been converted to use start and size instread of
start and end addresses. The patch was origianlly for adding
__clean_dcache_area_poc() which will be used in pmem driver to clean
dcache to the PoC(Point of Coherency) in arch_wb_cache_pmem().

The functionality of __clean_dcache_area_poc() was equivalent to
__dma_clean_range(). The difference was __dma_clean_range() uses the end
address, but __clean_dcache_area_poc() uses the size to clean.

Thus, __clean_dcache_area_poc() has been revised with a fall through
function of __dma_clean_range() after the change that __dma_* routines
use start and size instead of using start and end.

Signed-off-by: Kwangwoo Lee <kwangwoo.lee@xxxxxx>
---
arch/arm64/include/asm/cacheflush.h | 3 +-
arch/arm64/mm/cache.S | 71 +++++++++++++++++++------------------
arch/arm64/mm/dma-mapping.c | 6 ++--
3 files changed, 41 insertions(+), 39 deletions(-)

diff --git a/arch/arm64/include/asm/cacheflush.h b/arch/arm64/include/asm/cacheflush.h
index c64268d..2e5fb97 100644
--- a/arch/arm64/include/asm/cacheflush.h
+++ b/arch/arm64/include/asm/cacheflush.h
@@ -68,6 +68,7 @@
extern void flush_cache_range(struct vm_area_struct *vma, unsigned long start, unsigned long end);
extern void flush_icache_range(unsigned long start, unsigned long end);
extern void __flush_dcache_area(void *addr, size_t len);
+extern void __clean_dcache_area_poc(void *addr, size_t len);
extern void __clean_dcache_area_pou(void *addr, size_t len);
extern long __flush_cache_user_range(unsigned long start, unsigned long end);

@@ -85,7 +86,7 @@ static inline void flush_cache_page(struct vm_area_struct *vma,
*/
extern void __dma_map_area(const void *, size_t, int);
extern void __dma_unmap_area(const void *, size_t, int);
-extern void __dma_flush_range(const void *, const void *);
+extern void __dma_flush_area(const void *, size_t);

/*
* Copy user data from/to a page which is mapped into a different
diff --git a/arch/arm64/mm/cache.S b/arch/arm64/mm/cache.S
index 50ff9ba..4415c1b 100644
--- a/arch/arm64/mm/cache.S
+++ b/arch/arm64/mm/cache.S
@@ -110,14 +110,16 @@ ENDPROC(__clean_dcache_area_pou)
* - end - end address of region
*/
ENTRY(__inval_cache_range)
+ sub x1, x1, x0
/* FALLTHROUGH */

/*
- * __dma_inv_range(start, end)
+ * __dma_inv_area(start, size)
* - start - virtual start address of region
- * - end - virtual end address of region
+ * - size - size in question
*/
-__dma_inv_range:
+__dma_inv_area:
+ add x1, x1, x0
dcache_line_size x2, x3
sub x3, x2, #1
tst x1, x3 // end cache line aligned?
@@ -136,46 +138,47 @@ __dma_inv_range:
dsb sy
ret
ENDPIPROC(__inval_cache_range)
-ENDPROC(__dma_inv_range)
+ENDPROC(__dma_inv_area)
+
+/*
+ * __clean_dcache_area_poc(kaddr, size)
+ *
+ * Ensure that any D-cache lines for the interval [kaddr, kaddr+size)
+ * are cleaned to the PoC.
+ *
+ * - kaddr - kernel address
+ * - size - size in question
+ */
+ENTRY(__clean_dcache_area_poc)
+ /* FALLTHROUGH */

/*
- * __dma_clean_range(start, end)
+ * __dma_clean_area(start, size)
* - start - virtual start address of region
- * - end - virtual end address of region
+ * - size - size in question
*/
-__dma_clean_range:
- dcache_line_size x2, x3
- sub x3, x2, #1
- bic x0, x0, x3
-1:
+__dma_clean_area:
alternative_if_not ARM64_WORKAROUND_CLEAN_CACHE
- dc cvac, x0
+ dcache_by_line_op cvac, sy, x0, x1, x2, x3
alternative_else
- dc civac, x0
+ dcache_by_line_op civac, sy, x0, x1, x2, x3
alternative_endif
- add x0, x0, x2
- cmp x0, x1
- b.lo 1b
- dsb sy
ret
-ENDPROC(__dma_clean_range)
+ENDPIPROC(__clean_dcache_area_poc)
+ENDPROC(__dma_clean_area)

/*
- * __dma_flush_range(start, end)
+ * __dma_flush_area(start, size)
+ *
+ * clean & invalidate D / U line
+ *
* - start - virtual start address of region
- * - end - virtual end address of region
+ * - size - size in question
*/
-ENTRY(__dma_flush_range)
- dcache_line_size x2, x3
- sub x3, x2, #1
- bic x0, x0, x3
-1: dc civac, x0 // clean & invalidate D / U line
- add x0, x0, x2
- cmp x0, x1
- b.lo 1b
- dsb sy
+ENTRY(__dma_flush_area)
+ dcache_by_line_op civac, sy, x0, x1, x2, x3
ret
-ENDPIPROC(__dma_flush_range)
+ENDPIPROC(__dma_flush_area)

/*
* __dma_map_area(start, size, dir)
@@ -184,10 +187,9 @@ ENDPIPROC(__dma_flush_range)
* - dir - DMA direction
*/
ENTRY(__dma_map_area)
- add x1, x1, x0
cmp w2, #DMA_FROM_DEVICE
- b.eq __dma_inv_range
- b __dma_clean_range
+ b.eq __dma_inv_area
+ b __dma_clean_area
ENDPIPROC(__dma_map_area)

/*
@@ -197,8 +199,7 @@ ENDPIPROC(__dma_map_area)
* - dir - DMA direction
*/
ENTRY(__dma_unmap_area)
- add x1, x1, x0
cmp w2, #DMA_TO_DEVICE
- b.ne __dma_inv_range
+ b.ne __dma_inv_area
ret
ENDPIPROC(__dma_unmap_area)
diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
index c566ec8..e0b0712 100644
--- a/arch/arm64/mm/dma-mapping.c
+++ b/arch/arm64/mm/dma-mapping.c
@@ -165,7 +165,7 @@ static void *__dma_alloc(struct device *dev, size_t size,
return ptr;

/* remove any dirty cache lines on the kernel alias */
- __dma_flush_range(ptr, ptr + size);
+ __dma_flush_area(ptr, size);

/* create a coherent mapping */
page = virt_to_page(ptr);
@@ -377,7 +377,7 @@ static int __init atomic_pool_init(void)
void *page_addr = page_address(page);

memset(page_addr, 0, atomic_pool_size);
- __dma_flush_range(page_addr, page_addr + atomic_pool_size);
+ __dma_flush_area(page_addr, atomic_pool_size);

atomic_pool = gen_pool_create(PAGE_SHIFT, -1);
if (!atomic_pool)
@@ -535,7 +535,7 @@ fs_initcall(dma_debug_do_init);
/* Thankfully, all cache ops are by VA so we can ignore phys here */
static void flush_page(struct device *dev, const void *virt, phys_addr_t phys)
{
- __dma_flush_range(virt, virt + PAGE_SIZE);
+ __dma_flush_area(virt, PAGE_SIZE);
}

static void *__iommu_alloc_attrs(struct device *dev, size_t size,
--
2.5.0