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Subject[PATCH] ARM: mm: clean-up in order to reduce to call kmap_high_get()
Date
In kmap_atomic(), kmap_high_get() is invoked for checking already
mapped area. In __flush_dcache_page() and dma_cache_maint_page(),
we explicitly call kmap_high_get() before kmap_atomic()
when cache_is_vipt(), so kmap_high_get() can be invoked twice.
This is useless operation, so remove one.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>

diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index c7e3759..b7711be 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -822,16 +822,16 @@ static void dma_cache_maint_page(struct page *page, unsigned long offset,
if (PageHighMem(page)) {
if (len + offset > PAGE_SIZE)
len = PAGE_SIZE - offset;
- vaddr = kmap_high_get(page);
- if (vaddr) {
- vaddr += offset;
- op(vaddr, len, dir);
- kunmap_high(page);
- } else if (cache_is_vipt()) {
- /* unmapped pages might still be cached */
+ if (cache_is_vipt()) {
vaddr = kmap_atomic(page);
op(vaddr + offset, len, dir);
kunmap_atomic(vaddr);
+ } else {
+ vaddr = kmap_high_get(page);
+ if (vaddr) {
+ op(vaddr + offset, len, dir);
+ kunmap_high(page);
+ }
}
} else {
vaddr = page_address(page) + offset;
diff --git a/arch/arm/mm/flush.c b/arch/arm/mm/flush.c
index 1c8f7f5..e6a03d0 100644
--- a/arch/arm/mm/flush.c
+++ b/arch/arm/mm/flush.c
@@ -170,15 +170,18 @@ void __flush_dcache_page(struct address_space *mapping, struct page *page)
if (!PageHighMem(page)) {
__cpuc_flush_dcache_area(page_address(page), PAGE_SIZE);
} else {
- void *addr = kmap_high_get(page);
- if (addr) {
- __cpuc_flush_dcache_area(addr, PAGE_SIZE);
- kunmap_high(page);
- } else if (cache_is_vipt()) {
- /* unmapped pages might still be cached */
+ void *addr;
+
+ if (cache_is_vipt()) {
addr = kmap_atomic(page);
__cpuc_flush_dcache_area(addr, PAGE_SIZE);
kunmap_atomic(addr);
+ } else {
+ addr = kmap_high_get(page);
+ if (addr) {
+ __cpuc_flush_dcache_area(addr, PAGE_SIZE);
+ kunmap_high(page);
+ }
}
}

--
1.7.9.5


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