From bd6df57481b329dfeeb4889068848ee4f4761561 Mon Sep 17 00:00:00 2001 From: Paul Mundt Date: Wed, 9 Sep 2009 14:22:15 +0900 Subject: [PATCH] sh: Kill off segment-based d-cache flushing on SH-4. This kills off the unrolled segment based flushers on SH-4 and switches over to a generic unrolled approach derived from the writethrough segment flusher. Signed-off-by: Paul Mundt --- arch/sh/mm/cache-sh4.c | 291 +++-------------------------------------- 1 file changed, 20 insertions(+), 271 deletions(-) diff --git a/arch/sh/mm/cache-sh4.c b/arch/sh/mm/cache-sh4.c index f0999606686f..92b7d947db94 100644 --- a/arch/sh/mm/cache-sh4.c +++ b/arch/sh/mm/cache-sh4.c @@ -29,14 +29,6 @@ static void __flush_cache_4096(unsigned long addr, unsigned long phys, unsigned long exec_offset); -/* - * This is initialised here to ensure that it is not placed in the BSS. If - * that were to happen, note that cache_init gets called before the BSS is - * cleared, so this would get nulled out which would be hopeless. - */ -static void (*__flush_dcache_segment_fn)(unsigned long, unsigned long) = - (void (*)(unsigned long, unsigned long))0xdeadbeef; - /* * Write back the range of D-cache, and purge the I-cache. * @@ -158,10 +150,27 @@ static void __uses_jump_to_uncached flush_icache_all(void) local_irq_restore(flags); } -static inline void flush_dcache_all(void) +static void flush_dcache_all(void) { - (*__flush_dcache_segment_fn)(0UL, boot_cpu_data.dcache.way_size); - wmb(); + unsigned long addr, end_addr, entry_offset; + + end_addr = CACHE_OC_ADDRESS_ARRAY + + (current_cpu_data.dcache.sets << + current_cpu_data.dcache.entry_shift) * + current_cpu_data.dcache.ways; + + entry_offset = 1 << current_cpu_data.dcache.entry_shift; + + for (addr = CACHE_OC_ADDRESS_ARRAY; addr < end_addr; ) { + __raw_writel(0, addr); addr += entry_offset; + __raw_writel(0, addr); addr += entry_offset; + __raw_writel(0, addr); addr += entry_offset; + __raw_writel(0, addr); addr += entry_offset; + __raw_writel(0, addr); addr += entry_offset; + __raw_writel(0, addr); addr += entry_offset; + __raw_writel(0, addr); addr += entry_offset; + __raw_writel(0, addr); addr += entry_offset; + } } static void sh4_flush_cache_all(void *unused) @@ -347,245 +356,6 @@ static void __flush_cache_4096(unsigned long addr, unsigned long phys, } while (--way_count != 0); } -/* - * Break the 1, 2 and 4 way variants of this out into separate functions to - * avoid nearly all the overhead of having the conditional stuff in the function - * bodies (+ the 1 and 2 way cases avoid saving any registers too). - * - * We want to eliminate unnecessary bus transactions, so this code uses - * a non-obvious technique. - * - * Loop over a cache way sized block of, one cache line at a time. For each - * line, use movca.a to cause the current cache line contents to be written - * back, but without reading anything from main memory. However this has the - * side effect that the cache is now caching that memory location. So follow - * this with a cache invalidate to mark the cache line invalid. And do all - * this with interrupts disabled, to avoid the cache line being accidently - * evicted while it is holding garbage. - * - * This also breaks in a number of circumstances: - * - if there are modifications to the region of memory just above - * empty_zero_page (for example because a breakpoint has been placed - * there), then these can be lost. - * - * This is because the the memory address which the cache temporarily - * caches in the above description is empty_zero_page. So the - * movca.l hits the cache (it is assumed that it misses, or at least - * isn't dirty), modifies the line and then invalidates it, losing the - * required change. - * - * - If caches are disabled or configured in write-through mode, then - * the movca.l writes garbage directly into memory. - */ -static void __flush_dcache_segment_writethrough(unsigned long start, - unsigned long extent_per_way) -{ - unsigned long addr; - int i; - - addr = CACHE_OC_ADDRESS_ARRAY | (start & cpu_data->dcache.entry_mask); - - while (extent_per_way) { - for (i = 0; i < cpu_data->dcache.ways; i++) - __raw_writel(0, addr + cpu_data->dcache.way_incr * i); - - addr += cpu_data->dcache.linesz; - extent_per_way -= cpu_data->dcache.linesz; - } -} - -static void __flush_dcache_segment_1way(unsigned long start, - unsigned long extent_per_way) -{ - unsigned long orig_sr, sr_with_bl; - unsigned long base_addr; - unsigned long way_incr, linesz, way_size; - struct cache_info *dcache; - register unsigned long a0, a0e; - - asm volatile("stc sr, %0" : "=r" (orig_sr)); - sr_with_bl = orig_sr | (1<<28); - base_addr = ((unsigned long)&empty_zero_page[0]); - - /* - * The previous code aligned base_addr to 16k, i.e. the way_size of all - * existing SH-4 D-caches. Whilst I don't see a need to have this - * aligned to any better than the cache line size (which it will be - * anyway by construction), let's align it to at least the way_size of - * any existing or conceivable SH-4 D-cache. -- RPC - */ - base_addr = ((base_addr >> 16) << 16); - base_addr |= start; - - dcache = &boot_cpu_data.dcache; - linesz = dcache->linesz; - way_incr = dcache->way_incr; - way_size = dcache->way_size; - - a0 = base_addr; - a0e = base_addr + extent_per_way; - do { - asm volatile("ldc %0, sr" : : "r" (sr_with_bl)); - asm volatile("movca.l r0, @%0\n\t" - "ocbi @%0" : : "r" (a0)); - a0 += linesz; - asm volatile("movca.l r0, @%0\n\t" - "ocbi @%0" : : "r" (a0)); - a0 += linesz; - asm volatile("movca.l r0, @%0\n\t" - "ocbi @%0" : : "r" (a0)); - a0 += linesz; - asm volatile("movca.l r0, @%0\n\t" - "ocbi @%0" : : "r" (a0)); - asm volatile("ldc %0, sr" : : "r" (orig_sr)); - a0 += linesz; - } while (a0 < a0e); -} - -static void __flush_dcache_segment_2way(unsigned long start, - unsigned long extent_per_way) -{ - unsigned long orig_sr, sr_with_bl; - unsigned long base_addr; - unsigned long way_incr, linesz, way_size; - struct cache_info *dcache; - register unsigned long a0, a1, a0e; - - asm volatile("stc sr, %0" : "=r" (orig_sr)); - sr_with_bl = orig_sr | (1<<28); - base_addr = ((unsigned long)&empty_zero_page[0]); - - /* See comment under 1-way above */ - base_addr = ((base_addr >> 16) << 16); - base_addr |= start; - - dcache = &boot_cpu_data.dcache; - linesz = dcache->linesz; - way_incr = dcache->way_incr; - way_size = dcache->way_size; - - a0 = base_addr; - a1 = a0 + way_incr; - a0e = base_addr + extent_per_way; - do { - asm volatile("ldc %0, sr" : : "r" (sr_with_bl)); - asm volatile("movca.l r0, @%0\n\t" - "movca.l r0, @%1\n\t" - "ocbi @%0\n\t" - "ocbi @%1" : : - "r" (a0), "r" (a1)); - a0 += linesz; - a1 += linesz; - asm volatile("movca.l r0, @%0\n\t" - "movca.l r0, @%1\n\t" - "ocbi @%0\n\t" - "ocbi @%1" : : - "r" (a0), "r" (a1)); - a0 += linesz; - a1 += linesz; - asm volatile("movca.l r0, @%0\n\t" - "movca.l r0, @%1\n\t" - "ocbi @%0\n\t" - "ocbi @%1" : : - "r" (a0), "r" (a1)); - a0 += linesz; - a1 += linesz; - asm volatile("movca.l r0, @%0\n\t" - "movca.l r0, @%1\n\t" - "ocbi @%0\n\t" - "ocbi @%1" : : - "r" (a0), "r" (a1)); - asm volatile("ldc %0, sr" : : "r" (orig_sr)); - a0 += linesz; - a1 += linesz; - } while (a0 < a0e); -} - -static void __flush_dcache_segment_4way(unsigned long start, - unsigned long extent_per_way) -{ - unsigned long orig_sr, sr_with_bl; - unsigned long base_addr; - unsigned long way_incr, linesz, way_size; - struct cache_info *dcache; - register unsigned long a0, a1, a2, a3, a0e; - - asm volatile("stc sr, %0" : "=r" (orig_sr)); - sr_with_bl = orig_sr | (1<<28); - base_addr = ((unsigned long)&empty_zero_page[0]); - - /* See comment under 1-way above */ - base_addr = ((base_addr >> 16) << 16); - base_addr |= start; - - dcache = &boot_cpu_data.dcache; - linesz = dcache->linesz; - way_incr = dcache->way_incr; - way_size = dcache->way_size; - - a0 = base_addr; - a1 = a0 + way_incr; - a2 = a1 + way_incr; - a3 = a2 + way_incr; - a0e = base_addr + extent_per_way; - do { - asm volatile("ldc %0, sr" : : "r" (sr_with_bl)); - asm volatile("movca.l r0, @%0\n\t" - "movca.l r0, @%1\n\t" - "movca.l r0, @%2\n\t" - "movca.l r0, @%3\n\t" - "ocbi @%0\n\t" - "ocbi @%1\n\t" - "ocbi @%2\n\t" - "ocbi @%3\n\t" : : - "r" (a0), "r" (a1), "r" (a2), "r" (a3)); - a0 += linesz; - a1 += linesz; - a2 += linesz; - a3 += linesz; - asm volatile("movca.l r0, @%0\n\t" - "movca.l r0, @%1\n\t" - "movca.l r0, @%2\n\t" - "movca.l r0, @%3\n\t" - "ocbi @%0\n\t" - "ocbi @%1\n\t" - "ocbi @%2\n\t" - "ocbi @%3\n\t" : : - "r" (a0), "r" (a1), "r" (a2), "r" (a3)); - a0 += linesz; - a1 += linesz; - a2 += linesz; - a3 += linesz; - asm volatile("movca.l r0, @%0\n\t" - "movca.l r0, @%1\n\t" - "movca.l r0, @%2\n\t" - "movca.l r0, @%3\n\t" - "ocbi @%0\n\t" - "ocbi @%1\n\t" - "ocbi @%2\n\t" - "ocbi @%3\n\t" : : - "r" (a0), "r" (a1), "r" (a2), "r" (a3)); - a0 += linesz; - a1 += linesz; - a2 += linesz; - a3 += linesz; - asm volatile("movca.l r0, @%0\n\t" - "movca.l r0, @%1\n\t" - "movca.l r0, @%2\n\t" - "movca.l r0, @%3\n\t" - "ocbi @%0\n\t" - "ocbi @%1\n\t" - "ocbi @%2\n\t" - "ocbi @%3\n\t" : : - "r" (a0), "r" (a1), "r" (a2), "r" (a3)); - asm volatile("ldc %0, sr" : : "r" (orig_sr)); - a0 += linesz; - a1 += linesz; - a2 += linesz; - a3 += linesz; - } while (a0 < a0e); -} - extern void __weak sh4__flush_region_init(void); /* @@ -593,32 +363,11 @@ extern void __weak sh4__flush_region_init(void); */ void __init sh4_cache_init(void) { - unsigned int wt_enabled = !!(__raw_readl(CCR) & CCR_CACHE_WT); - printk("PVR=%08x CVR=%08x PRR=%08x\n", ctrl_inl(CCN_PVR), ctrl_inl(CCN_CVR), ctrl_inl(CCN_PRR)); - if (wt_enabled) - __flush_dcache_segment_fn = __flush_dcache_segment_writethrough; - else { - switch (boot_cpu_data.dcache.ways) { - case 1: - __flush_dcache_segment_fn = __flush_dcache_segment_1way; - break; - case 2: - __flush_dcache_segment_fn = __flush_dcache_segment_2way; - break; - case 4: - __flush_dcache_segment_fn = __flush_dcache_segment_4way; - break; - default: - panic("unknown number of cache ways\n"); - break; - } - } - local_flush_icache_range = sh4_flush_icache_range; local_flush_dcache_page = sh4_flush_dcache_page; local_flush_cache_all = sh4_flush_cache_all; -- 2.39.5