From: George G. Davis gdavis@mvista.com
The ARM1136 cache_flush() function uses the "mcr p15, 0, rn, c7, c7, 0" instruction which means "Invalidate Both Caches" when in fact the intent is to clean and invalidate all caches. So add an "mcr p15, 0, %0, c7, c10, 0" instruction to "Clean Entire Data Cache" prior to the "Invalidate Both Caches" instruction to insure that memory is consistent with any dirty cache lines.
Also fix a couple of "flush v*" comments in ARM1136 cpu_init_crit() so that they correctly describe the actual ARM1136 CP15 C7 Cache Operations used.
Signed-off-by: George G. Davis gdavis@mvista.com --- arch/arm/cpu/arm1136/cpu.c | 1 + arch/arm/cpu/arm1136/start.S | 4 ++-- 2 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/arm/cpu/arm1136/cpu.c b/arch/arm/cpu/arm1136/cpu.c index ade7f46..2b91631 100644 --- a/arch/arm/cpu/arm1136/cpu.c +++ b/arch/arm/cpu/arm1136/cpu.c @@ -71,6 +71,7 @@ static void cache_flush(void) { unsigned long i = 0;
+ asm ("mcr p15, 0, %0, c7, c10, 0": :"r" (i)); /* clean entire data cache */ asm ("mcr p15, 0, %0, c7, c7, 0": :"r" (i)); /* invalidate both caches and flush btb */ asm ("mcr p15, 0, %0, c7, c10, 4": :"r" (i)); /* mem barrier to sync things */ } diff --git a/arch/arm/cpu/arm1136/start.S b/arch/arm/cpu/arm1136/start.S index 957f438..922d01c 100644 --- a/arch/arm/cpu/arm1136/start.S +++ b/arch/arm/cpu/arm1136/start.S @@ -226,8 +226,8 @@ cpu_init_crit: * flush v4 I/D caches */ mov r0, #0 - mcr p15, 0, r0, c7, c7, 0 /* flush v3/v4 cache */ - mcr p15, 0, r0, c8, c7, 0 /* flush v4 TLB */ + mcr p15, 0, r0, c7, c7, 0 /* Invalidate I+D+BTB caches */ + mcr p15, 0, r0, c8, c7, 0 /* Invalidate Unified TLB */
/* * disable MMU stuff and caches