Blackfin arch: Fix bug - KGDB single step into the middle of a 4 bytes instruction...

[linux-2.6-omap-h63xx.git] / arch / blackfin / mach-common / cache.S

diff --git a/arch/blackfin/mach-common/cache.S b/arch/blackfin/mach-common/cache.S
index 3c98dacbf2892960ec4053f3c3bfde85bbc01fd9..aa0648c6a9feb19111d2b8e60e96dfef12bc9340 100644 (file)
--- a/arch/blackfin/mach-common/cache.S
+++ b/arch/blackfin/mach-common/cache.S
@@ -66,11 +66,33 @@
 
 /* Invalidate all instruction cache lines assocoiated with this memory area */
 ENTRY(_blackfin_icache_flush_range)
+/*
+ * Walkaround to avoid loading wrong instruction after invalidating icache
+ * and following sequence is met.
+ *
+ * 1) One instruction address is cached in the instruction cache.
+ * 2) This instruction in SDRAM is changed.
+ * 3) IFLASH[P0] is executed only once in blackfin_icache_flush_range().
+ * 4) This instruction is executed again, but the old one is loaded.
+ */
+       P0 = R0;
+       IFLUSH[P0];
        do_flush IFLUSH, , nop
 ENDPROC(_blackfin_icache_flush_range)
 
 /* Flush all cache lines assocoiated with this area of memory. */
 ENTRY(_blackfin_icache_dcache_flush_range)
+/*
+ * Walkaround to avoid loading wrong instruction after invalidating icache
+ * and following sequence is met.
+ *
+ * 1) One instruction address is cached in the instruction cache.
+ * 2) This instruction in SDRAM is changed.
+ * 3) IFLASH[P0] is executed only once in blackfin_icache_flush_range().
+ * 4) This instruction is executed again, but the old one is loaded.
+ */
+       P0 = R0;
+       IFLUSH[P0];
        do_flush FLUSH, IFLUSH
 ENDPROC(_blackfin_icache_dcache_flush_range)