[U-Boot] [PATCH v3 05/10] armv7: integrate cache maintenance support
Aneesh V
aneesh at ti.com
Thu May 12 14:11:11 CEST 2011
- Enable I-cache on bootup
- Enable MMU and D-cache immediately after relocation
- Do necessary initialization before enabling d-cache and MMU
- Changes to cleanup_before_linux()
- Make changes according to the new framework
Signed-off-by: Aneesh V <aneesh at ti.com>
---
V2:
* Changes for -march=armv7a -> armv5 change
* Removed the print inside the weakly linked stub function -
__arm_init_before_mmu
---
arch/arm/cpu/armv7/cpu.c | 45 +++++++++++++++++++------------------------
arch/arm/cpu/armv7/start.S | 18 ++++++++++++++++-
arch/arm/lib/board.c | 6 +++++
arch/arm/lib/cache-cp15.c | 7 ++++++
arch/arm/lib/cache.c | 5 ----
5 files changed, 50 insertions(+), 31 deletions(-)
diff --git a/arch/arm/cpu/armv7/cpu.c b/arch/arm/cpu/armv7/cpu.c
index 7f28d87..5c69d04 100644
--- a/arch/arm/cpu/armv7/cpu.c
+++ b/arch/arm/cpu/armv7/cpu.c
@@ -34,13 +34,10 @@
#include <common.h>
#include <command.h>
#include <asm/system.h>
-#include <asm/cache.h>
#include <asm/armv7.h>
int cleanup_before_linux(void)
{
- unsigned int i;
-
/*
* this function is called just before we call linux
* it prepares the processor for linux
@@ -49,31 +46,29 @@ int cleanup_before_linux(void)
*/
disable_interrupts();
- /* turn off I/D-cache */
+ /*
+ * Turn off I-cache and invalidate it
+ */
icache_disable();
- dcache_disable();
+ invalidate_icache_all();
- /* invalidate I-cache */
- cache_flush();
-
-#ifndef CONFIG_L2_OFF
- /* turn off L2 cache */
- l2_cache_disable();
- /* invalidate L2 cache also */
- invalidate_dcache(get_device_type());
-#endif
- i = 0;
- /* mem barrier to sync up things */
- asm("mcr p15, 0, %0, c7, c10, 4": :"r"(i));
+ /*
+ * turn off D-cache
+ * dcache_disable() in turn flushes the d-cache and disables MMU
+ */
+ dcache_disable();
-#ifndef CONFIG_L2_OFF
- l2_cache_enable();
-#endif
+ /*
+ * After D-cache is flushed and before it is disabled there may
+ * be some new valid entries brought into the cache. We are sure
+ * that these lines are not dirty and will not affect our execution.
+ * (because unwinding the call-stack and setting a bit in CP15 SCTRL
+ * is all we did during this. We have not pushed anything on to the
+ * stack. Neither have we affected any static data)
+ * So just invalidate the entire d-cache again to avoid coherency
+ * problems for kernel
+ */
+ invalidate_dcache_all();
return 0;
}
-
-static void cache_flush(void)
-{
- asm ("mcr p15, 0, %0, c7, c5, 0": :"r" (0));
-}
diff --git a/arch/arm/cpu/armv7/start.S b/arch/arm/cpu/armv7/start.S
index 2929fc7..13e2d44 100644
--- a/arch/arm/cpu/armv7/start.S
+++ b/arch/arm/cpu/armv7/start.S
@@ -255,6 +255,14 @@ clbss_l:str r2, [r0] /* clear loop... */
* initialization, now running from RAM.
*/
jump_2_ram:
+/*
+ * If I-cache is enabled invalidate it
+ */
+#ifndef CONFIG_SYS_NO_ICACHE
+ mcr p15, 0, r0, c7, c5, 0 @ invalidate icache
+ mcr p15, 0, r0, c7, c10, 4 @ DSB
+ mcr p15, 0, r0, c7, c5, 4 @ ISB
+#endif
ldr r0, _board_init_r_ofs
adr r1, _start
add lr, r0, r1
@@ -290,6 +298,9 @@ cpu_init_crit:
mov r0, #0 @ set up for MCR
mcr p15, 0, r0, c8, c7, 0 @ invalidate TLBs
mcr p15, 0, r0, c7, c5, 0 @ invalidate icache
+ mcr p15, 0, r0, c7, c5, 6 @ invalidate BP array
+ mcr p15, 0, r0, c7, c10, 4 @ DSB
+ mcr p15, 0, r0, c7, c5, 4 @ ISB
/*
* disable MMU stuff and caches
@@ -298,7 +309,12 @@ cpu_init_crit:
bic r0, r0, #0x00002000 @ clear bits 13 (--V-)
bic r0, r0, #0x00000007 @ clear bits 2:0 (-CAM)
orr r0, r0, #0x00000002 @ set bit 1 (--A-) Align
- orr r0, r0, #0x00000800 @ set bit 12 (Z---) BTB
+ orr r0, r0, #0x00000800 @ set bit 11 (Z---) BTB
+#ifdef CONFIG_SYS_NO_ICACHE
+ bic r0, r0, #0x00001000 @ clear bit 12 (I) I-cache
+#else
+ orr r0, r0, #0x00001000 @ set bit 12 (I) I-cache
+#endif
mcr p15, 0, r0, c1, c0, 0
/*
diff --git a/arch/arm/lib/board.c b/arch/arm/lib/board.c
index 1a784a1..85469ae 100644
--- a/arch/arm/lib/board.c
+++ b/arch/arm/lib/board.c
@@ -464,6 +464,12 @@ void board_init_r (gd_t *id, ulong dest_addr)
gd->flags |= GD_FLG_RELOC; /* tell others: relocation done */
monitor_flash_len = _end_ofs;
+ /*
+ * Enable D$:
+ * I$, if needed, must be already enabled in start.S
+ */
+ dcache_enable();
+
debug ("monitor flash len: %08lX\n", monitor_flash_len);
board_init(); /* Setup chipselects */
diff --git a/arch/arm/lib/cache-cp15.c b/arch/arm/lib/cache-cp15.c
index d9175f0..fd97c45 100644
--- a/arch/arm/lib/cache-cp15.c
+++ b/arch/arm/lib/cache-cp15.c
@@ -34,6 +34,12 @@
DECLARE_GLOBAL_DATA_PTR;
+void __arm_init_before_mmu(void)
+{
+}
+void arm_init_before_mmu(void)
+ __attribute__((weak, alias("__arm_init_before_mmu")));
+
static void cp_delay (void)
{
volatile int i;
@@ -65,6 +71,7 @@ static inline void mmu_setup(void)
int i;
u32 reg;
+ arm_init_before_mmu();
/* Set up an identity-mapping for all 4GB, rw for everyone */
for (i = 0; i < 4096; i++)
page_table[i] = i << 20 | (3 << 10) | 0x12;
diff --git a/arch/arm/lib/cache.c b/arch/arm/lib/cache.c
index 27123cd..dc3242c 100644
--- a/arch/arm/lib/cache.c
+++ b/arch/arm/lib/cache.c
@@ -38,11 +38,6 @@ void __flush_cache(unsigned long start, unsigned long size)
/* disable write buffer as well (page 2-22) */
asm("mcr p15, 0, %0, c7, c10, 4" : : "r" (0));
#endif
-#ifdef CONFIG_OMAP34XX
- void v7_flush_cache_all(void);
-
- v7_flush_cache_all();
-#endif
return;
}
void flush_cache(unsigned long start, unsigned long size)
--
1.7.0.4
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