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Subject[PATCH 1/3] nds32: Correct flush_dcache_page function
Date
1. Disable local irq before d-cache write-back and invalidate.
The cpu_dcache_wbinval_page function is composed of d-cache
write-back and invalidate. If the local irq is enabled when calling
cpu_dcache_wbinval_page, the content of d-cache is possibly updated
between write-back and invalidate. In this case, the updated data will
be dropped due to the following d-cache invalidation. Therefore, we
disable the local irq before calling cpu_dcache_wbinval_page.

2. Correct the data write-back for page aliasing case.
Only the page whose (page->index << PAGE_SHIFT) is located at the
same page color as page_address(page) needs to execute data write-back
in flush_dcache_page function.

Signed-off-by: Vincent Chen <vincentc@andestech.com>
---
arch/nds32/mm/cacheflush.c | 21 ++++++++++++---------
1 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/arch/nds32/mm/cacheflush.c b/arch/nds32/mm/cacheflush.c
index 6eb786a..288cf10 100644
--- a/arch/nds32/mm/cacheflush.c
+++ b/arch/nds32/mm/cacheflush.c
@@ -198,17 +198,20 @@ void flush_dcache_page(struct page *page)
if (mapping && !mapping_mapped(mapping))
set_bit(PG_dcache_dirty, &page->flags);
else {
- int i, pc;
- unsigned long vto, kaddr, flags;
+ unsigned long kaddr, flags;
+
kaddr = (unsigned long)page_address(page);
- cpu_dcache_wbinval_page(kaddr);
- pc = CACHE_SET(DCACHE) * CACHE_LINE_SIZE(DCACHE) / PAGE_SIZE;
local_irq_save(flags);
- for (i = 0; i < pc; i++) {
- vto =
- kremap0(kaddr + i * PAGE_SIZE, page_to_phys(page));
- cpu_dcache_wbinval_page(vto);
- kunmap01(vto);
+ cpu_dcache_wbinval_page(kaddr);
+ if (mapping) {
+ unsigned long vaddr, kto;
+
+ vaddr = page->index << PAGE_SHIFT;
+ if (aliasing(vaddr, kaddr)) {
+ kto = kremap0(vaddr, page_to_phys(page));
+ cpu_dcache_wbinval_page(kto);
+ kunmap01(kto);
+ }
}
local_irq_restore(flags);
}
--
1.7.1
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