Workaround for the global I cache invalidation ARM1136 Errata

Errata 411920 - Invalidation of the Instruction Cache operation can
fail. This Errata is present in 1136, 1156 and 1176. It does not
affect the MPCore. This patch implements the ARM Ltd recommended
workaround.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

arch/arm/Kconfig

@@ -478,6 +478,16 @@ config ARM_ERRATA_364296
 	  processor into full low interrupt latency mode. ARM11MPCore
 	  is not affected.
 
+config ARM_ERRATA_411920
+	bool "Workaround for the global I cache invalidation on ARM1136"
+	depends on CPU_V6 && !SMP
+	default n
+	help
+	  Invalidation of the Instruction Cache operation can
+	  fail. This Erratum is present in 1136, 1156 and 1176. It
+	  does not affect the MPCore. This option enables the ARM Ltd.
+	  recommended workaround.
+
 endmenu
 
 source "arch/arm/common/Kconfig"

arch/arm/mm/cache-v6.S

@@ -20,6 +20,39 @@
 #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
+ * Errata 411920 - Invalidate Instruction Cache operation can fail. This
+ * Errata 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
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	mov	pc, lr
+#endif
+
 /*
  *	v6_flush_cache_all()
  *
@@ -31,7 +64,11 @@ 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
@@ -103,7 +140,11 @@ 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

arch/arm/mm/flush.c

@@ -31,10 +31,14 @@ static void flush_pfn_alias(unsigned long pfn, unsigned long vaddr)
 
 	asm(	"mcrr	p15, 0, %1, %0, c14\n"
 	"	mcr	p15, 0, %2, c7, c10, 4\n"
+#ifndef CONFIG_ARM_ERRATA_411920
 	"	mcr	p15, 0, %2, c7, c5, 0\n"
+#else
+	"	bl	v6_icache_inval_all\n"
+#endif
 	    :
 	    : "r" (to), "r" (to + PAGE_SIZE - L1_CACHE_BYTES), "r" (zero)
-	    : "cc");
+	    : "r0", "r1", "lr");
 }
 
 void flush_cache_mm(struct mm_struct *mm)
@@ -47,11 +51,15 @@ void flush_cache_mm(struct mm_struct *mm)
 
 	if (cache_is_vipt_aliasing()) {
 		asm(	"mcr	p15, 0, %0, c7, c14, 0\n"
+		"	mcr	p15, 0, %0, c7, c10, 4\n"
+#ifndef CONFIG_ARM_ERRATA_411920
 		"	mcr	p15, 0, %0, c7, c5, 0\n"
-		"	mcr	p15, 0, %0, c7, c10, 4"
+#else
+		"	bl	v6_icache_inval_all\n"
+#endif
 		    :
 		    : "r" (0)
-		    : "cc");
+		    : "r0", "r1", "lr", "cc");
 	}
 }
 
@@ -66,11 +74,15 @@ void flush_cache_range(struct vm_area_struct *vma, unsigned long start, unsigned
 
 	if (cache_is_vipt_aliasing()) {
 		asm(	"mcr	p15, 0, %0, c7, c14, 0\n"
+		"	mcr	p15, 0, %0, c7, c10, 4\n"
+#ifndef CONFIG_ARM_ERRATA_411920
 		"	mcr	p15, 0, %0, c7, c5, 0\n"
-		"	mcr	p15, 0, %0, c7, c10, 4"
+#else
+		"	bl	v6_icache_inval_all\n"
+#endif
 		    :
 		    : "r" (0)
-		    : "cc");
+		    : "r0", "r1", "lr", "cc");
 	}
 }