1 /* 2 * (C) Copyright 2002 3 * Wolfgang Denk, DENX Software Engineering, wd@denx.de. 4 * 5 * SPDX-License-Identifier: GPL-2.0+ 6 */ 7 8 #include <common.h> 9 #include <asm/system.h> 10 #include <asm/cache.h> 11 #include <linux/compiler.h> 12 13 #if !(defined(CONFIG_SYS_ICACHE_OFF) && defined(CONFIG_SYS_DCACHE_OFF)) 14 15 DECLARE_GLOBAL_DATA_PTR; 16 17 __weak void arm_init_before_mmu(void) 18 { 19 } 20 21 __weak void arm_init_domains(void) 22 { 23 } 24 25 static void cp_delay (void) 26 { 27 volatile int i; 28 29 /* copro seems to need some delay between reading and writing */ 30 for (i = 0; i < 100; i++) 31 nop(); 32 asm volatile("" : : : "memory"); 33 } 34 35 void set_section_dcache(int section, enum dcache_option option) 36 { 37 u32 *page_table = (u32 *)gd->arch.tlb_addr; 38 u32 value; 39 40 value = (section << MMU_SECTION_SHIFT) | (3 << 10); 41 value |= option; 42 page_table[section] = value; 43 } 44 45 __weak void mmu_page_table_flush(unsigned long start, unsigned long stop) 46 { 47 debug("%s: Warning: not implemented\n", __func__); 48 } 49 50 void mmu_set_region_dcache_behaviour(phys_addr_t start, size_t size, 51 enum dcache_option option) 52 { 53 u32 *page_table = (u32 *)gd->arch.tlb_addr; 54 unsigned long upto, end; 55 56 end = ALIGN(start + size, MMU_SECTION_SIZE) >> MMU_SECTION_SHIFT; 57 start = start >> MMU_SECTION_SHIFT; 58 debug("%s: start=%pa, size=%zu, option=%d\n", __func__, &start, size, 59 option); 60 for (upto = start; upto < end; upto++) 61 set_section_dcache(upto, option); 62 mmu_page_table_flush((u32)&page_table[start], (u32)&page_table[end]); 63 } 64 65 __weak void dram_bank_mmu_setup(int bank) 66 { 67 bd_t *bd = gd->bd; 68 int i; 69 70 debug("%s: bank: %d\n", __func__, bank); 71 for (i = bd->bi_dram[bank].start >> 20; 72 i < (bd->bi_dram[bank].start >> 20) + (bd->bi_dram[bank].size >> 20); 73 i++) { 74 #if defined(CONFIG_SYS_ARM_CACHE_WRITETHROUGH) 75 set_section_dcache(i, DCACHE_WRITETHROUGH); 76 #elif defined(CONFIG_SYS_ARM_CACHE_WRITEALLOC) 77 set_section_dcache(i, DCACHE_WRITEALLOC); 78 #else 79 set_section_dcache(i, DCACHE_WRITEBACK); 80 #endif 81 } 82 } 83 84 /* to activate the MMU we need to set up virtual memory: use 1M areas */ 85 static inline void mmu_setup(void) 86 { 87 int i; 88 u32 reg; 89 90 arm_init_before_mmu(); 91 /* Set up an identity-mapping for all 4GB, rw for everyone */ 92 for (i = 0; i < 4096; i++) 93 set_section_dcache(i, DCACHE_OFF); 94 95 for (i = 0; i < CONFIG_NR_DRAM_BANKS; i++) { 96 dram_bank_mmu_setup(i); 97 } 98 99 #ifdef CONFIG_CPU_V7 100 /* Set TTBR0 */ 101 reg = gd->arch.tlb_addr & TTBR0_BASE_ADDR_MASK; 102 #if defined(CONFIG_SYS_ARM_CACHE_WRITETHROUGH) 103 reg |= TTBR0_RGN_WT | TTBR0_IRGN_WT; 104 #elif defined(CONFIG_SYS_ARM_CACHE_WRITEALLOC) 105 reg |= TTBR0_RGN_WBWA | TTBR0_IRGN_WBWA; 106 #else 107 reg |= TTBR0_RGN_WB | TTBR0_IRGN_WB; 108 #endif 109 asm volatile("mcr p15, 0, %0, c2, c0, 0" 110 : : "r" (reg) : "memory"); 111 #else 112 /* Copy the page table address to cp15 */ 113 asm volatile("mcr p15, 0, %0, c2, c0, 0" 114 : : "r" (gd->arch.tlb_addr) : "memory"); 115 #endif 116 /* Set the access control to all-supervisor */ 117 asm volatile("mcr p15, 0, %0, c3, c0, 0" 118 : : "r" (~0)); 119 120 arm_init_domains(); 121 122 /* and enable the mmu */ 123 reg = get_cr(); /* get control reg. */ 124 cp_delay(); 125 set_cr(reg | CR_M); 126 } 127 128 static int mmu_enabled(void) 129 { 130 return get_cr() & CR_M; 131 } 132 133 /* cache_bit must be either CR_I or CR_C */ 134 static void cache_enable(uint32_t cache_bit) 135 { 136 uint32_t reg; 137 138 /* The data cache is not active unless the mmu is enabled too */ 139 if ((cache_bit == CR_C) && !mmu_enabled()) 140 mmu_setup(); 141 reg = get_cr(); /* get control reg. */ 142 cp_delay(); 143 set_cr(reg | cache_bit); 144 } 145 146 /* cache_bit must be either CR_I or CR_C */ 147 static void cache_disable(uint32_t cache_bit) 148 { 149 uint32_t reg; 150 151 reg = get_cr(); 152 cp_delay(); 153 154 if (cache_bit == CR_C) { 155 /* if cache isn;t enabled no need to disable */ 156 if ((reg & CR_C) != CR_C) 157 return; 158 /* if disabling data cache, disable mmu too */ 159 cache_bit |= CR_M; 160 } 161 reg = get_cr(); 162 cp_delay(); 163 if (cache_bit == (CR_C | CR_M)) 164 flush_dcache_all(); 165 set_cr(reg & ~cache_bit); 166 } 167 #endif 168 169 #ifdef CONFIG_SYS_ICACHE_OFF 170 void icache_enable (void) 171 { 172 return; 173 } 174 175 void icache_disable (void) 176 { 177 return; 178 } 179 180 int icache_status (void) 181 { 182 return 0; /* always off */ 183 } 184 #else 185 void icache_enable(void) 186 { 187 cache_enable(CR_I); 188 } 189 190 void icache_disable(void) 191 { 192 cache_disable(CR_I); 193 } 194 195 int icache_status(void) 196 { 197 return (get_cr() & CR_I) != 0; 198 } 199 #endif 200 201 #ifdef CONFIG_SYS_DCACHE_OFF 202 void dcache_enable (void) 203 { 204 return; 205 } 206 207 void dcache_disable (void) 208 { 209 return; 210 } 211 212 int dcache_status (void) 213 { 214 return 0; /* always off */ 215 } 216 #else 217 void dcache_enable(void) 218 { 219 cache_enable(CR_C); 220 } 221 222 void dcache_disable(void) 223 { 224 cache_disable(CR_C); 225 } 226 227 int dcache_status(void) 228 { 229 return (get_cr() & CR_C) != 0; 230 } 231 #endif 232