1 /* 2 * arch/sh/mm/cache-sh7705.c 3 * 4 * Copyright (C) 1999, 2000 Niibe Yutaka 5 * Copyright (C) 2004 Alex Song 6 * 7 * This file is subject to the terms and conditions of the GNU General Public 8 * License. See the file "COPYING" in the main directory of this archive 9 * for more details. 10 * 11 */ 12 #include <linux/init.h> 13 #include <linux/mman.h> 14 #include <linux/mm.h> 15 #include <linux/fs.h> 16 #include <linux/threads.h> 17 #include <asm/addrspace.h> 18 #include <asm/page.h> 19 #include <asm/pgtable.h> 20 #include <asm/processor.h> 21 #include <asm/cache.h> 22 #include <asm/io.h> 23 #include <linux/uaccess.h> 24 #include <asm/pgalloc.h> 25 #include <asm/mmu_context.h> 26 #include <asm/cacheflush.h> 27 28 /* 29 * The 32KB cache on the SH7705 suffers from the same synonym problem 30 * as SH4 CPUs 31 */ 32 static inline void cache_wback_all(void) 33 { 34 unsigned long ways, waysize, addrstart; 35 36 ways = current_cpu_data.dcache.ways; 37 waysize = current_cpu_data.dcache.sets; 38 waysize <<= current_cpu_data.dcache.entry_shift; 39 40 addrstart = CACHE_OC_ADDRESS_ARRAY; 41 42 do { 43 unsigned long addr; 44 45 for (addr = addrstart; 46 addr < addrstart + waysize; 47 addr += current_cpu_data.dcache.linesz) { 48 unsigned long data; 49 int v = SH_CACHE_UPDATED | SH_CACHE_VALID; 50 51 data = __raw_readl(addr); 52 53 if ((data & v) == v) 54 __raw_writel(data & ~v, addr); 55 56 } 57 58 addrstart += current_cpu_data.dcache.way_incr; 59 } while (--ways); 60 } 61 62 /* 63 * Write back the range of D-cache, and purge the I-cache. 64 * 65 * Called from kernel/module.c:sys_init_module and routine for a.out format. 66 */ 67 static void sh7705_flush_icache_range(void *args) 68 { 69 struct flusher_data *data = args; 70 unsigned long start, end; 71 72 start = data->addr1; 73 end = data->addr2; 74 75 __flush_wback_region((void *)start, end - start); 76 } 77 78 /* 79 * Writeback&Invalidate the D-cache of the page 80 */ 81 static void __flush_dcache_page(unsigned long phys) 82 { 83 unsigned long ways, waysize, addrstart; 84 unsigned long flags; 85 86 phys |= SH_CACHE_VALID; 87 88 /* 89 * Here, phys is the physical address of the page. We check all the 90 * tags in the cache for those with the same page number as this page 91 * (by masking off the lowest 2 bits of the 19-bit tag; these bits are 92 * derived from the offset within in the 4k page). Matching valid 93 * entries are invalidated. 94 * 95 * Since 2 bits of the cache index are derived from the virtual page 96 * number, knowing this would reduce the number of cache entries to be 97 * searched by a factor of 4. However this function exists to deal with 98 * potential cache aliasing, therefore the optimisation is probably not 99 * possible. 100 */ 101 local_irq_save(flags); 102 jump_to_uncached(); 103 104 ways = current_cpu_data.dcache.ways; 105 waysize = current_cpu_data.dcache.sets; 106 waysize <<= current_cpu_data.dcache.entry_shift; 107 108 addrstart = CACHE_OC_ADDRESS_ARRAY; 109 110 do { 111 unsigned long addr; 112 113 for (addr = addrstart; 114 addr < addrstart + waysize; 115 addr += current_cpu_data.dcache.linesz) { 116 unsigned long data; 117 118 data = __raw_readl(addr) & (0x1ffffC00 | SH_CACHE_VALID); 119 if (data == phys) { 120 data &= ~(SH_CACHE_VALID | SH_CACHE_UPDATED); 121 __raw_writel(data, addr); 122 } 123 } 124 125 addrstart += current_cpu_data.dcache.way_incr; 126 } while (--ways); 127 128 back_to_cached(); 129 local_irq_restore(flags); 130 } 131 132 /* 133 * Write back & invalidate the D-cache of the page. 134 * (To avoid "alias" issues) 135 */ 136 static void sh7705_flush_dcache_page(void *arg) 137 { 138 struct page *page = arg; 139 struct address_space *mapping = page_mapping(page); 140 141 if (mapping && !mapping_mapped(mapping)) 142 clear_bit(PG_dcache_clean, &page->flags); 143 else 144 __flush_dcache_page(__pa(page_address(page))); 145 } 146 147 static void sh7705_flush_cache_all(void *args) 148 { 149 unsigned long flags; 150 151 local_irq_save(flags); 152 jump_to_uncached(); 153 154 cache_wback_all(); 155 back_to_cached(); 156 local_irq_restore(flags); 157 } 158 159 /* 160 * Write back and invalidate I/D-caches for the page. 161 * 162 * ADDRESS: Virtual Address (U0 address) 163 */ 164 static void sh7705_flush_cache_page(void *args) 165 { 166 struct flusher_data *data = args; 167 unsigned long pfn = data->addr2; 168 169 __flush_dcache_page(pfn << PAGE_SHIFT); 170 } 171 172 /* 173 * This is called when a page-cache page is about to be mapped into a 174 * user process' address space. It offers an opportunity for a 175 * port to ensure d-cache/i-cache coherency if necessary. 176 * 177 * Not entirely sure why this is necessary on SH3 with 32K cache but 178 * without it we get occasional "Memory fault" when loading a program. 179 */ 180 static void sh7705_flush_icache_page(void *page) 181 { 182 __flush_purge_region(page_address(page), PAGE_SIZE); 183 } 184 185 void __init sh7705_cache_init(void) 186 { 187 local_flush_icache_range = sh7705_flush_icache_range; 188 local_flush_dcache_page = sh7705_flush_dcache_page; 189 local_flush_cache_all = sh7705_flush_cache_all; 190 local_flush_cache_mm = sh7705_flush_cache_all; 191 local_flush_cache_dup_mm = sh7705_flush_cache_all; 192 local_flush_cache_range = sh7705_flush_cache_all; 193 local_flush_cache_page = sh7705_flush_cache_page; 194 local_flush_icache_page = sh7705_flush_icache_page; 195 } 196