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-rw-r--r--arch/powerpc/kernel/setup_32.c3
-rw-r--r--arch/powerpc/lib/copy_32.S6
2 files changed, 9 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/setup_32.c b/arch/powerpc/kernel/setup_32.c
index b316ab7..ad8c9db 100644
--- a/arch/powerpc/kernel/setup_32.c
+++ b/arch/powerpc/kernel/setup_32.c
@@ -110,6 +110,8 @@ notrace unsigned long __init early_init(unsigned long dt_ptr)
* This is called very early on the boot process, after a minimal
* MMU environment has been set up but before MMU_init is called.
*/
+extern unsigned int memset_nocache_branch; /* Insn to be replaced by NOP */
+
notrace void __init machine_init(u64 dt_ptr)
{
lockdep_init();
@@ -118,6 +120,7 @@ notrace void __init machine_init(u64 dt_ptr)
udbg_early_init();
patch_instruction((unsigned int *)&memcpy, PPC_INST_NOP);
+ patch_instruction(&memset_nocache_branch, PPC_INST_NOP);
/* Do some early initialization based on the flat device tree */
early_init_devtree(__va(dt_ptr));
diff --git a/arch/powerpc/lib/copy_32.S b/arch/powerpc/lib/copy_32.S
index da5847d..c44df2d 100644
--- a/arch/powerpc/lib/copy_32.S
+++ b/arch/powerpc/lib/copy_32.S
@@ -73,6 +73,10 @@ CACHELINE_MASK = (L1_CACHE_BYTES-1)
* Use dcbz on the complete cache lines in the destination
* to set them to zero. This requires that the destination
* area is cacheable. -- paulus
+ *
+ * During early init, cache might not be active yet, so dcbz cannot be used.
+ * We therefore skip the optimised bloc that uses dcbz. This jump is
+ * replaced by a nop once cache is active. This is done in machine_init()
*/
_GLOBAL(memset)
rlwimi r4,r4,8,16,23
@@ -88,6 +92,8 @@ _GLOBAL(memset)
subf r6,r0,r6
cmplwi 0,r4,0
bne 2f /* Use normal procedure if r4 is not zero */
+_GLOBAL(memset_nocache_branch)
+ b 2f /* Skip optimised bloc until cache is enabled */
clrlwi r7,r6,32-LG_CACHELINE_BYTES
add r8,r7,r5