ARM: 6379/1: Assume new page cache pages have dirty D-cache
There are places in Linux where writes to newly allocated page cache
pages happen without a subsequent call to flush_dcache_page() (several
PIO drivers including USB HCD). This patch changes the meaning of
PG_arch_1 to be PG_dcache_clean and always flush the D-cache for a newly
mapped page in update_mmu_cache().
The patch also sets the PG_arch_1 bit in the DMA cache maintenance
function to avoid additional cache flushing in update_mmu_cache().
Tested-by: Rabin Vincent <rabin.vincent@stericsson.com>
Cc: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/mm/flush.c b/arch/arm/mm/flush.c
index 87dd5ff..b4efce9 100644
--- a/arch/arm/mm/flush.c
+++ b/arch/arm/mm/flush.c
@@ -248,7 +248,7 @@
#ifndef CONFIG_SMP
if (mapping && !mapping_mapped(mapping))
- set_bit(PG_dcache_dirty, &page->flags);
+ clear_bit(PG_dcache_clean, &page->flags);
else
#endif
{
@@ -257,6 +257,7 @@
__flush_dcache_aliases(mapping, page);
else if (mapping)
__flush_icache_all();
+ set_bit(PG_dcache_clean, &page->flags);
}
}
EXPORT_SYMBOL(flush_dcache_page);