linux-m68k.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* [PATCH v2] m68k: fix ColdFire clear cache operation
@ 2012-07-11  0:37 gerg
  2012-07-11 15:51 ` Philippe De Muyter
  2012-07-16 19:13 ` Geert Uytterhoeven
  0 siblings, 2 replies; 5+ messages in thread
From: gerg @ 2012-07-11  0:37 UTC (permalink / raw)
  To: linux-m68k; +Cc: Greg Ungerer

From: Greg Ungerer <gerg@uclinux.org>

The code for clearing (invalidating) the ColdFire cache is actually performing
a push operation. Add functions to clear the cache, and fix cache_clear() to
call the appropriate clear cache function.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
---
 arch/m68k/include/asm/cacheflush_mm.h |   35 +++++++++++++++++++++++++++++++++
 arch/m68k/mm/memory.c                 |    2 +-
 2 files changed, 36 insertions(+), 1 deletions(-)

diff --git a/arch/m68k/include/asm/cacheflush_mm.h b/arch/m68k/include/asm/cacheflush_mm.h
index 8104bd8..b05990e 100644
--- a/arch/m68k/include/asm/cacheflush_mm.h
+++ b/arch/m68k/include/asm/cacheflush_mm.h
@@ -17,6 +17,41 @@
 #define DCACHE_SETMASK	0
 #endif
 
+/*
+ * ColdFire architecture has no way to clear individual cache lines, so we
+ * are stuck invalidating all the cache entries when we want a clear operation.
+ */
+static inline void clear_cf_icache(unsigned long start, unsigned long end)
+{
+	__asm__ __volatile__ (
+		"movec	%0,%%cacr\n\t"
+		"nop\n\t"
+		:
+		: "r" (CACHE_MODE | CACR_ICINVA | CACR_BCINVA));
+}
+
+static inline void clear_cf_dcache(unsigned long start, unsigned long end)
+{
+	__asm__ __volatile__ (
+		"movec	%0,%%cacr\n\t"
+		"nop\n\t"
+		:
+		: "r" (CACHE_MODE | CACR_DCINVA));
+}
+
+static inline void clear_cf_bcache(unsigned long start, unsigned long end)
+{
+	__asm__ __volatile__ (
+		"movec	%0,%%cacr\n\t"
+		"nop\n\t"
+		:
+		: "r" (CACHE_MODE | CACR_ICINVA | CACR_BCINVA | CACR_DCINVA));
+}
+
+/*
+ * Use the ColdFire cpushl instruction to push (and invalidate) cache lines.
+ * The start and end addresses are cache line numbers not memory addresses.
+ */
 static inline void flush_cf_icache(unsigned long start, unsigned long end)
 {
 	unsigned long set;
diff --git a/arch/m68k/mm/memory.c b/arch/m68k/mm/memory.c
index 250b8b7..51bc9d2 100644
--- a/arch/m68k/mm/memory.c
+++ b/arch/m68k/mm/memory.c
@@ -203,7 +203,7 @@ static inline void pushcl040(unsigned long paddr)
 void cache_clear (unsigned long paddr, int len)
 {
     if (CPU_IS_COLDFIRE) {
-	flush_cf_bcache(0, DCACHE_MAX_ADDR);
+	clear_cf_bcache(0, DCACHE_MAX_ADDR);
     } else if (CPU_IS_040_OR_060) {
 	int tmp;
 
-- 
1.7.0.4

^ permalink raw reply related	[flat|nested] 5+ messages in thread
end of thread, other threads:[~2012-07-17  6:09 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2012-07-11  0:37 [PATCH v2] m68k: fix ColdFire clear cache operation gerg
2012-07-11 15:51 ` Philippe De Muyter
2012-07-12  1:50   ` Greg Ungerer
2012-07-16 19:13 ` Geert Uytterhoeven
2012-07-17  6:03   ` Greg Ungerer

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).