[ARM] 5488/1: ARM errata: Invalidation of the Instruction Cache operation can fail

This patch implements the recommended workaround for erratum 411920
(ARM1136, ARM1156, ARM1176).

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 33 insertions, 0 deletions

diff --git a/arch/arm/mm/cache-v6.S b/arch/arm/mm/cache-v6.S
index 2c6c2a7c05a0..8f5c13f4c936 100644
--- a/arch/arm/mm/cache-v6.S
+++ b/arch/arm/mm/cache-v6.S
@@ -20,6 +20,31 @@
 #define D_CACHE_LINE_SIZE       32
 #define BTB_FLUSH_SIZE          8
 
+#ifdef CONFIG_ARM_ERRATA_411920
+/*
+ * Invalidate the entire I cache (this code is a workaround for the ARM1136
+ * erratum 411920 - Invalidate Instruction Cache operation can fail. This
+ * erratum is present in 1136, 1156 and 1176. It does not affect the MPCore.
+ *
+ * Registers:
+ *   r0 - set to 0
+ *   r1 - corrupted
+ */
+ENTRY(v6_icache_inval_all)
+        mov     r0, #0
+        mrs     r1, cpsr
+        cpsid   ifa                             @ disable interrupts
+        mcr     p15, 0, r0, c7, c5, 0           @ invalidate entire I-cache
+        mcr     p15, 0, r0, c7, c5, 0           @ invalidate entire I-cache
+        mcr     p15, 0, r0, c7, c5, 0           @ invalidate entire I-cache
+        mcr     p15, 0, r0, c7, c5, 0           @ invalidate entire I-cache
+        msr     cpsr_cx, r1                     @ restore interrupts
+        .rept   11                              @ ARM Ltd recommends at least
+        nop                                     @ 11 NOPs
+        .endr
+        mov     pc, lr
+#endif
+
 /*
  *      v6_flush_cache_all()
  *
@@ -31,8 +56,12 @@ ENTRY(v6_flush_kern_cache_all)
         mov     r0, #0
 #ifdef HARVARD_CACHE
         mcr     p15, 0, r0, c7, c14, 0          @ D cache clean+invalidate
+#ifndef CONFIG_ARM_ERRATA_411920
         mcr     p15, 0, r0, c7, c5, 0           @ I+BTB cache invalidate
 #else
+        b       v6_icache_inval_all
+#endif
+#else
         mcr     p15, 0, r0, c7, c15, 0          @ Cache clean+invalidate
 #endif
         mov     pc, lr
@@ -103,8 +132,12 @@ ENTRY(v6_coherent_user_range)
         mov     r0, #0
 #ifdef HARVARD_CACHE
         mcr     p15, 0, r0, c7, c10, 4          @ drain write buffer
+#ifndef CONFIG_ARM_ERRATA_411920
         mcr     p15, 0, r0, c7, c5, 0           @ I+BTB cache invalidate
 #else
+        b       v6_icache_inval_all
+#endif
+#else
         mcr     p15, 0, r0, c7, c5, 6           @ invalidate BTB
 #endif
         mov     pc, lr