lkml.org 
[lkml]   [2016]   [Feb]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 2/2] MIPS: Flush highmem pages from dcache in __flush_icache_page
Date
When a page is to be mapped executable for userspace, we can presume
that the icache doesn't contain anything valid for its address range but
we cannot be sure that its content has been written back from the dcache
to L2 or memory further out. If the icache fills from those memories,
ie. does not fill from the dcache, then we need to ensure that content
has been flushed from the dcache. This was being done for lowmem pages
but not for highmem pages. Fix this by mapping the page & flushing its
content from the dcache in __flush_icache_page, before the page is
provided to userland.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>

---

arch/mips/mm/cache.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/arch/mips/mm/cache.c b/arch/mips/mm/cache.c
index 3f159ca..734cb2f 100644
--- a/arch/mips/mm/cache.c
+++ b/arch/mips/mm/cache.c
@@ -16,6 +16,7 @@
#include <linux/mm.h>

#include <asm/cacheflush.h>
+#include <asm/highmem.h>
#include <asm/processor.h>
#include <asm/cpu.h>
#include <asm/cpu-features.h>
@@ -124,10 +125,14 @@ void __flush_icache_page(struct vm_area_struct *vma, struct page *page)
unsigned long addr;

if (PageHighMem(page))
- return;
+ addr = (unsigned long)kmap_atomic(page);
+ else
+ addr = (unsigned long)page_address(page);

- addr = (unsigned long) page_address(page);
flush_data_cache_page(addr);
+
+ if (PageHighMem(page))
+ __kunmap_atomic((void *)addr);
}
EXPORT_SYMBOL_GPL(__flush_icache_page);

--
2.7.1
\
 
 \ /
  Last update: 2016-02-22 19:41    [W:2.210 / U:0.024 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site