[PATCH v3 10/18] arm64: __inval_dcache_area to take end parameter instead of size

Fuad Tabba
2021-05-20T12:49:33Z

To be consistent with other functions with similar names and
functionality in cacheflush.h, cache.S, and cachetlb.rst, change
to specify the range in terms of start and end, as opposed to
start and size.

Because the code is shared with __dma_inv_area, it changes the
parameters for that as well. However, __dma_inv_area is local to
cache.S, so no other users are affected.

No functional change intended.

Reported-by: Will Deacon <will@kernel.org>
Signed-off-by: Fuad Tabba <tabba@google.com>
---
arch/arm64/include/asm/cacheflush.h | 2 +-
arch/arm64/kernel/head.S | 5 +----
arch/arm64/mm/cache.S | 16 +++++++++-------
arch/arm64/mm/flush.c | 2 +-
4 files changed, 12 insertions(+), 13 deletions(-)

diff --git a/arch/arm64/include/asm/cacheflush.h b/arch/arm64/include/asm/cacheflush.h
index a586afa84172..157234706817 100644
--- a/arch/arm64/include/asm/cacheflush.h
+++ b/arch/arm64/include/asm/cacheflush.h
@@ -59,7 +59,7 @@
extern void __flush_icache_range(unsigned long start, unsigned long end);
extern void invalidate_icache_range(unsigned long start, unsigned long end);
extern void __flush_dcache_area(void *addr, size_t len);
-extern void __inval_dcache_area(void *addr, size_t len);
+extern void __inval_dcache_area(unsigned long start, unsigned long end);
extern void __clean_dcache_area_poc(void *addr, size_t len);
extern void __clean_dcache_area_pop(void *addr, size_t len);
extern void __clean_dcache_area_pou(void *addr, size_t len);
diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
index 96873dfa67fd..8df0ac8d9123 100644
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S
@@ -117,7 +117,7 @@ SYM_CODE_START_LOCAL(preserve_boot_args)
dmb sy // needed before dc ivac with
// MMU off

- mov x1, #0x20 // 4 x 8 bytes
+ add x1, x0, #0x20 // 4 x 8 bytes
b __inval_dcache_area // tail call
SYM_CODE_END(preserve_boot_args)

@@ -268,7 +268,6 @@ SYM_FUNC_START_LOCAL(__create_page_tables)
*/
adrp x0, init_pg_dir
adrp x1, init_pg_end
- sub x1, x1, x0
bl __inval_dcache_area

/*
@@ -382,12 +381,10 @@ SYM_FUNC_START_LOCAL(__create_page_tables)

adrp x0, idmap_pg_dir
adrp x1, idmap_pg_end
- sub x1, x1, x0
bl __inval_dcache_area

adrp x0, init_pg_dir
adrp x1, init_pg_end
- sub x1, x1, x0
bl __inval_dcache_area

ret x28
diff --git a/arch/arm64/mm/cache.S b/arch/arm64/mm/cache.S
index 80da4b8718b6..5170d9ab450a 100644
--- a/arch/arm64/mm/cache.S
+++ b/arch/arm64/mm/cache.S
@@ -138,25 +138,24 @@ alternative_else_nop_endif
SYM_FUNC_END(__clean_dcache_area_pou)

/*
- * __inval_dcache_area(kaddr, size)
+ * __inval_dcache_area(start, end)
*
- * Ensure that any D-cache lines for the interval [kaddr, kaddr+size)
+ * Ensure that any D-cache lines for the interval [start, end)
* are invalidated. Any partial lines at the ends of the interval are
* also cleaned to PoC to prevent data loss.
*
- * - kaddr - kernel address
- * - size - size in question
+ * - start - kernel start address of region
+ * - end - kernel end address of region
*/
SYM_FUNC_START_LOCAL(__dma_inv_area)
SYM_FUNC_START_PI(__inval_dcache_area)
/* FALLTHROUGH */

/*
- * __dma_inv_area(start, size)
+ * __dma_inv_area(start, end)
* - start - virtual start address of region
- * - size - size in question
+ * - end - virtual end address of region
*/
- add x1, x1, x0
dcache_line_size x2, x3
sub x3, x2, #1
tst x1, x3 // end cache line aligned?
@@ -237,8 +236,10 @@ SYM_FUNC_END_PI(__dma_flush_area)
* - dir - DMA direction
*/
SYM_FUNC_START_PI(__dma_map_area)
+ add x1, x0, x1
cmp w2, #DMA_FROM_DEVICE
b.eq __dma_inv_area
+ sub x1, x1, x0
b __dma_clean_area
SYM_FUNC_END_PI(__dma_map_area)

@@ -249,6 +250,7 @@ SYM_FUNC_END_PI(__dma_map_area)
* - dir - DMA direction
*/
SYM_FUNC_START_PI(__dma_unmap_area)
+ add x1, x0, x1
cmp w2, #DMA_TO_DEVICE
b.ne __dma_inv_area
ret
diff --git a/arch/arm64/mm/flush.c b/arch/arm64/mm/flush.c
index ac485163a4a7..4e3505c2bea6 100644
--- a/arch/arm64/mm/flush.c
+++ b/arch/arm64/mm/flush.c
@@ -88,7 +88,7 @@ EXPORT_SYMBOL_GPL(arch_wb_cache_pmem);

void arch_invalidate_pmem(void *addr, size_t size)
{
- __inval_dcache_area(addr, size);
+ __inval_dcache_area((unsigned long)addr, (unsigned long)addr + size);
}
EXPORT_SYMBOL_GPL(arch_invalidate_pmem);
#endif
--
2.31.1.751.gd2f1c929bd-goog