[U-Boot] [PATCH 12/13] ARM: UniPhier: disable L2 cache by lowlevel_init of U-Boot proper
Masahiro Yamada
yamada.masahiro at socionext.com
Sun Mar 22 16:07:32 CET 2015
The L2 cache is used as a temporary SRAM on SPL.
Now the secondary CPUs store the necessary code for jumping to
Linux on their L1 I-caches. So, the L2 cache can be disabled
much earlier, at the very entry of U-Boot proper (lowlevel_init).
This makes the boot sequence clearer.
Also, as the L1 cache has been disabled by the start.S,
enable_caches() does not need to do it again.
Signed-off-by: Masahiro Yamada <yamada.masahiro at socionext.com>
---
arch/arm/mach-uniphier/cache_uniphier.c | 17 -----------------
arch/arm/mach-uniphier/late_lowlevel_init.S | 5 +++++
2 files changed, 5 insertions(+), 17 deletions(-)
diff --git a/arch/arm/mach-uniphier/cache_uniphier.c b/arch/arm/mach-uniphier/cache_uniphier.c
index 4bf01bc..c1e9164 100644
--- a/arch/arm/mach-uniphier/cache_uniphier.c
+++ b/arch/arm/mach-uniphier/cache_uniphier.c
@@ -122,23 +122,6 @@ void v7_outer_cache_disable(void)
void enable_caches(void)
{
- uint32_t reg;
-
- /*
- * UniPhier SoCs must use L2 cache for init stack pointer.
- * We disable L2 and L1 in this order.
- * If CONFIG_SYS_DCACHE_OFF is not defined,
- * caches are enabled again with a new page table.
- */
-
- /* L2 disable */
- v7_outer_cache_disable();
-
- /* L1 disable */
- reg = get_cr();
- reg &= ~(CR_C | CR_M);
- set_cr(reg);
-
#ifndef CONFIG_SYS_DCACHE_OFF
dcache_enable();
#endif
diff --git a/arch/arm/mach-uniphier/late_lowlevel_init.S b/arch/arm/mach-uniphier/late_lowlevel_init.S
index 22be2a2..1363364 100644
--- a/arch/arm/mach-uniphier/late_lowlevel_init.S
+++ b/arch/arm/mach-uniphier/late_lowlevel_init.S
@@ -6,7 +6,12 @@
*/
#include <linux/linkage.h>
+#include <mach/ssc-regs.h>
ENTRY(lowlevel_init)
+ ldr r1, = SSCC
+ ldr r0, [r1]
+ bic r0, r0, #SSCC_ON @ L2 disable
+ str r0, [r1]
mov pc, lr
ENDPROC(lowlevel_init)
--
1.9.1
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