[PATCH] i386: inline asm cleanup
i386 Inline asm cleanup. Use cr/dr accessor functions.
Also, a potential bugfix. Also, some CR accessors really should be volatile.
Reads from CR0 (numeric state may change in an exception handler), writes to
CR4 (flipping CR4.TSD) and reads from CR2 (page fault) prevent instruction
re-ordering. I did not add memory clobber to CR3 / CR4 / CR0 updates, as it
was not there to begin with, and in no case should kernel memory be clobbered,
except when doing a TLB flush, which already has memory clobber.
I noticed that page invalidation does not have a memory clobber. I can't find
a bug as a result, but there is definitely a potential for a bug here:
#define __flush_tlb_single(addr) \
__asm__ __volatile__("invlpg %0": :"m" (*(char *) addr))
Signed-off-by: Zachary Amsden <zach@vmware.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/asm-i386/agp.h b/include/asm-i386/agp.h
index b82f5f3..9075083 100644
--- a/include/asm-i386/agp.h
+++ b/include/asm-i386/agp.h
@@ -19,7 +19,7 @@
/* Could use CLFLUSH here if the cpu supports it. But then it would
need to be called for each cacheline of the whole page so it may not be
worth it. Would need a page for it. */
-#define flush_agp_cache() asm volatile("wbinvd":::"memory")
+#define flush_agp_cache() wbinvd()
/* Convert a physical address to an address suitable for the GART. */
#define phys_to_gart(x) (x)