- 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@ti.com --- arch/arm/cpu/armv7/cpu.c | 47 +++++++++++++++++++------------------------ arch/arm/cpu/armv7/start.S | 18 +++++++++++++++- arch/arm/lib/board.c | 6 +++++ arch/arm/lib/cache-cp15.c | 9 ++++++++ 4 files changed, 53 insertions(+), 27 deletions(-)
diff --git a/arch/arm/cpu/armv7/cpu.c b/arch/arm/cpu/armv7/cpu.c index a01e0d6..b418304 100644 --- a/arch/arm/cpu/armv7/cpu.c +++ b/arch/arm/cpu/armv7/cpu.c @@ -38,13 +38,10 @@ #ifndef CONFIG_L2_OFF #include <asm/arch/sys_proto.h> #endif - -static void cache_flush(void); +#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 @@ -53,31 +50,29 @@ 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 684f2d2..7d17f1e 100644 --- a/arch/arm/cpu/armv7/start.S +++ b/arch/arm/cpu/armv7/start.S @@ -241,6 +241,14 @@ 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 + dsb + isb +#endif ldr r0, _board_init_r_ofs adr r1, _start add lr, r0, r1 @@ -276,6 +284,9 @@ 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 */ + dsb + isb
/* * disable MMU stuff and caches @@ -284,7 +295,12 @@ 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 7266381..bef32a6 100644 --- a/arch/arm/lib/board.c +++ b/arch/arm/lib/board.c @@ -459,6 +459,12 @@ void board_init_r (gd_t *id, ulong dest_addr)
gd->flags |= GD_FLG_RELOC; /* tell others: relocation done */
+ /* + * Enable D$: + * I$, if needed, must be already enabled in start.S + */ + dcache_enable(); + monitor_flash_len = _bss_start_ofs; 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..ca526fb 100644 --- a/arch/arm/lib/cache-cp15.c +++ b/arch/arm/lib/cache-cp15.c @@ -34,6 +34,14 @@
DECLARE_GLOBAL_DATA_PTR;
+void __arm_init_before_mmu(void) +{ + puts("__arm_init_before_mmu: dummy implementation! " + "real implementation missing!!\n"); +} +void arm_init_before_mmu(void) + __attribute__((weak, alias("__arm_init_before_mmu"))); + static void cp_delay (void) { volatile int i; @@ -65,6 +73,7 @@ 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;