diff options
| author | Haavard Skinnemoen <hskinnemoen@atmel.com> | 2006-10-01 08:29:14 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-10-01 09:39:31 +0200 |
| commit | db71daabad0821996483dfe309c4bc81d6755a70 (patch) | |
| tree | 10e60d91178ccb0d1fd1c47321fc6c096db926e5 /lib/ioremap.c | |
| parent | [PATCH] Generic ioremap_page_range: implementation (diff) | |
| download | linux-db71daabad0821996483dfe309c4bc81d6755a70.tar.xz linux-db71daabad0821996483dfe309c4bc81d6755a70.zip | |
[PATCH] Generic ioremap_page_range: flush_cache_vmap
The existing implementation of ioremap_page_range(), which was taken
from i386, does this:
flush_cache_all();
/* modify page tables */
flush_tlb_all();
I think this is a bit defensive, so this patch changes the generic
implementation to do:
/* modify page tables */
flush_cache_vmap(start, end);
instead, which is similar to what vmalloc() does. This should still
be correct because we never modify existing PTEs. According to
James Bottomley:
The problem the flush_tlb_all() is trying to solve is to avoid stale tlb
entries in the ioremap area. We're just being conservative by flushing
on both map and unmap. Technically what vmalloc/vfree does (only flush
the tlb on unmap) is just fine because it means that the only tlb
entries in the remap area must belong to in-use mappings.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Andi Kleen <ak@suse.de>
Cc: <linux-m32r@ml.linux-m32r.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Kyle McMartin <kyle@parisc-linux.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'lib/ioremap.c')
| -rw-r--r-- | lib/ioremap.c | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/lib/ioremap.c b/lib/ioremap.c index 29c810ec9813..99fa277f9f7b 100644 --- a/lib/ioremap.c +++ b/lib/ioremap.c @@ -76,8 +76,6 @@ int ioremap_page_range(unsigned long addr, BUG_ON(addr >= end); - flush_cache_all(); - start = addr; phys_addr -= addr; pgd = pgd_offset_k(addr); @@ -88,7 +86,7 @@ int ioremap_page_range(unsigned long addr, break; } while (pgd++, addr = next, addr != end); - flush_tlb_all(); + flush_cache_vmap(start, end); return err; } |