From: Michal Simek Date: Mon, 26 Apr 2010 06:54:13 +0000 (+0200) Subject: microblaze: Optimize CACHE_LOOP_LIMITS and CACHE_RANGE_LOOP macros X-Git-Tag: v5.15~29700^2~1 X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=3274c5707c22221574b396d140d0db3480a2027a;p=mirror_ubuntu-kernels.git microblaze: Optimize CACHE_LOOP_LIMITS and CACHE_RANGE_LOOP macros 1. Remove CACHE_ALL_LOOP2 macro because it is identical to CACHE_ALL_LOOP 2. Change BUG_ON to WARN_ON 3. Remove end aligned from CACHE_LOOP_LIMITS. C implementation do not need aligned end address and ASM code do aligned in their macros 4. ASM optimized CACHE_RANGE_LOOP_1/2 macros needs to get aligned end address. Because end address is compound from start + size, end address is the first address which is exclude. Here is the corresponding code which describe it. + int align = ~(line_length - 1); + end = ((end & align) == end) ? end - line_length : end & align; a) end is aligned: it is necessary to subtruct line length because we don't want to work with next cacheline b) end address is not aligned: Just align it to be ready for ASM code. Signed-off-by: Michal Simek --- diff --git a/arch/microblaze/kernel/cpu/cache.c b/arch/microblaze/kernel/cpu/cache.c index 19dae71dbaaf..21c3a92394de 100644 --- a/arch/microblaze/kernel/cpu/cache.c +++ b/arch/microblaze/kernel/cpu/cache.c @@ -96,13 +96,16 @@ static inline void __disable_dcache_nomsr(void) } -/* Helper macro for computing the limits of cache range loops */ +/* Helper macro for computing the limits of cache range loops + * + * End address can be unaligned which is OK for C implementation. + * ASM implementation align it in ASM macros + */ #define CACHE_LOOP_LIMITS(start, end, cache_line_length, cache_size) \ do { \ int align = ~(cache_line_length - 1); \ end = min(start + cache_size, end); \ start &= align; \ - end = ((end & align) + cache_line_length); \ } while (0); /* @@ -111,9 +114,9 @@ do { \ */ #define CACHE_ALL_LOOP(cache_size, line_length, op) \ do { \ - unsigned int len = cache_size; \ + unsigned int len = cache_size - line_length; \ int step = -line_length; \ - BUG_ON(step >= 0); \ + WARN_ON(step >= 0); \ \ __asm__ __volatile__ (" 1: " #op " %0, r0; \ bgtid %0, 1b; \ @@ -122,26 +125,21 @@ do { \ : "memory"); \ } while (0); - -#define CACHE_ALL_LOOP2(cache_size, line_length, op) \ -do { \ - unsigned int len = cache_size; \ - int step = -line_length; \ - BUG_ON(step >= 0); \ - \ - __asm__ __volatile__ (" 1: " #op " r0, %0; \ - bgtid %0, 1b; \ - addk %0, %0, %1; \ - " : : "r" (len), "r" (step) \ - : "memory"); \ -} while (0); - -/* for wdc.flush/clear */ +/* Used for wdc.flush/clear which can use rB for offset which is not possible + * to use for simple wdc or wic. + * + * start address is cache aligned + * end address is not aligned, if end is aligned then I have to substract + * cacheline length because I can't flush/invalidate the next cacheline. + * If is not, I align it because I will flush/invalidate whole line. + */ #define CACHE_RANGE_LOOP_2(start, end, line_length, op) \ do { \ int step = -line_length; \ + int align = ~(line_length - 1); \ + end = ((end & align) == end) ? end - line_length : end & align; \ int count = end - start; \ - BUG_ON(count <= 0); \ + WARN_ON(count < 0); \ \ __asm__ __volatile__ (" 1: " #op " %0, %1; \ bgtid %1, 1b; \ @@ -154,7 +152,9 @@ do { \ #define CACHE_RANGE_LOOP_1(start, end, line_length, op) \ do { \ int volatile temp; \ - BUG_ON(end - start <= 0); \ + int align = ~(line_length - 1); \ + end = ((end & align) == end) ? end - line_length : end & align; \ + WARN_ON(end - start < 0); \ \ __asm__ __volatile__ (" 1: " #op " %1, r0; \ cmpu %0, %1, %2; \ @@ -360,8 +360,12 @@ static void __invalidate_dcache_all_noirq_wt(void) #endif } -/* FIXME this is weird - should be only wdc but not work - * MS: I am getting bus errors and other weird things */ +/* FIXME It is blindly invalidation as is expected + * but can't be called on noMMU in microblaze_cache_init below + * + * MS: noMMU kernel won't boot if simple wdc is used + * The reason should be that there are discared data which kernel needs + */ static void __invalidate_dcache_all_wb(void) { #ifndef ASM_LOOP @@ -369,12 +373,12 @@ static void __invalidate_dcache_all_wb(void) #endif pr_debug("%s\n", __func__); #ifdef ASM_LOOP - CACHE_ALL_LOOP2(cpuinfo.dcache_size, cpuinfo.dcache_line_length, - wdc.clear) + CACHE_ALL_LOOP(cpuinfo.dcache_size, cpuinfo.dcache_line_length, + wdc) #else for (i = 0; i < cpuinfo.dcache_size; i += cpuinfo.dcache_line_length) - __asm__ __volatile__ ("wdc.clear %0, r0;" \ + __asm__ __volatile__ ("wdc %0, r0;" \ : : "r" (i)); #endif } @@ -650,7 +654,11 @@ void microblaze_cache_init(void) } } } - invalidate_dcache(); +/* FIXME Invalidation is done in U-BOOT + * WT cache: Data is already written to main memory + * WB cache: Discard data on noMMU which caused that kernel doesn't boot + */ + /* invalidate_dcache(); */ enable_dcache(); invalidate_icache();