[PATCH] [POWERPC] Xilinx: clear data caches.
Stephen Neuendorffer
stephen.neuendorffer at xilinx.com
Wed Dec 5 07:49:10 EST 2007
This code is needed to boot without a boot loader.
Grant: I'm not sure where the right place to put this is. I'm assuming we'll actually need some boot code that is not generic? Also, note that there is a V4FX errata workaround in arch/ppc/boot/head.S, which probably also needs to get pulled to powerpc.
Signed-off-by: Stephen Neuendorffer <stephen.neuendorffer at xilinx.com>
---
arch/powerpc/boot/raw-platform.c | 22 ++++++++++++++++++++++
1 files changed, 22 insertions(+), 0 deletions(-)
diff --git a/arch/powerpc/boot/raw-platform.c b/arch/powerpc/boot/raw-platform.c
index b9caeee..2a5e493 100644
--- a/arch/powerpc/boot/raw-platform.c
+++ b/arch/powerpc/boot/raw-platform.c
@@ -24,6 +24,28 @@ void platform_init(unsigned long r3, unsigned long r4, unsigned long r5,
unsigned long r6, unsigned long r7)
{
u64 memsize64 = memsize[0];
+ static const unsigned long line_size = 32;
+ static const unsigned long congruence_classes = 256;
+ unsigned long addr;
+ unsigned long dccr;
+
+ /*
+ * Invalidate the data cache if the data cache is turned off.
+ * - The 405 core does not invalidate the data cache on power-up
+ * or reset but does turn off the data cache. We cannot assume
+ * that the cache contents are valid.
+ * - If the data cache is turned on this must have been done by
+ * a bootloader and we assume that the cache contents are
+ * valid.
+ */
+ __asm__("mfdccr %0": "=r" (dccr));
+ if (dccr == 0) {
+ for (addr = 0;
+ addr < (congruence_classes * line_size);
+ addr += line_size) {
+ __asm__("dccci 0,%0": :"b"(addr));
+ }
+ }
if (mem_size_cells == 2) {
memsize64 <<= 32;
--
1.5.3.4-dirty
More information about the Linuxppc-dev
mailing list