powerpc: Cleanup, consolidating icache dirtying logic

[David Gibson]

The code to mark a page as icache dirty (so that it will later be
icache-dcache flushed when we try to execute from it) is duplicated in
three places: flush_dcache_page() does this marking and nothing else,
but clear_user_page() and copy_user_page() duplicate it, since those
functions make the page icache dirty themselves.

This patch makes those other functions call flush_dcache_page()
instead, so the logic's all in one place.  This will make life less
confusing if we ever need to tweak the details of the the lazy icache
flush mechanism.

 arch/powerpc/mm/mem.c |   14 ++------------
 1 file changed, 2 insertions(+), 12 deletions(-)

Signed-off-by: David Gibson <dwg at au1.ibm.com>

Index: working-2.6/arch/powerpc/mm/mem.c
===================================================================
--- working-2.6.orig/arch/powerpc/mm/mem.c	2006-02-06 12:58:07.000000000 +1100
+++ working-2.6/arch/powerpc/mm/mem.c	2006-02-06 13:20:29.000000000 +1100
@@ -435,17 +435,12 @@ void clear_user_page(void *page, unsigne
 {
 	clear_page(page);
 
-	if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
-		return;
 	/*
 	 * We shouldnt have to do this, but some versions of glibc
 	 * require it (ld.so assumes zero filled pages are icache clean)
 	 * - Anton
 	 */
-
-	/* avoid an atomic op if possible */
-	if (test_bit(PG_arch_1, &pg->flags))
-		clear_bit(PG_arch_1, &pg->flags);
+	flush_dcache_page(pg);
 }
 EXPORT_SYMBOL(clear_user_page);
 
@@ -469,12 +464,7 @@ void copy_user_page(void *vto, void *vfr
 		return;
 #endif
 
-	if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
-		return;
-
-	/* avoid an atomic op if possible */
-	if (test_bit(PG_arch_1, &pg->flags))
-		clear_bit(PG_arch_1, &pg->flags);
+	flush_dcache_page(pg);
 }
 
 void flush_icache_user_range(struct vm_area_struct *vma, struct page *page,

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson