1 /* 2 * Copyright (C) 2008-2009 ST-Ericsson AB 3 * License terms: GNU General Public License (GPL) version 2 4 * TCM memory handling for ARM systems 5 * 6 * Author: Linus Walleij <linus.walleij@stericsson.com> 7 * Author: Rickard Andersson <rickard.andersson@stericsson.com> 8 */ 9 #include <linux/init.h> 10 #include <linux/kernel.h> 11 #include <linux/module.h> 12 #include <linux/stddef.h> 13 #include <linux/ioport.h> 14 #include <linux/genalloc.h> 15 #include <linux/string.h> /* memcpy */ 16 #include <asm/page.h> /* PAGE_SHIFT */ 17 #include <asm/cputype.h> 18 #include <asm/mach/map.h> 19 #include <mach/memory.h> 20 #include "tcm.h" 21 22 /* Scream and warn about misuse */ 23 #if !defined(ITCM_OFFSET) || !defined(ITCM_END) || \ 24 !defined(DTCM_OFFSET) || !defined(DTCM_END) 25 #error "TCM support selected but offsets not defined!" 26 #endif 27 28 static struct gen_pool *tcm_pool; 29 30 /* TCM section definitions from the linker */ 31 extern char __itcm_start, __sitcm_text, __eitcm_text; 32 extern char __dtcm_start, __sdtcm_data, __edtcm_data; 33 34 /* 35 * TCM memory resources 36 */ 37 static struct resource dtcm_res = { 38 .name = "DTCM RAM", 39 .start = DTCM_OFFSET, 40 .end = DTCM_END, 41 .flags = IORESOURCE_MEM 42 }; 43 44 static struct resource itcm_res = { 45 .name = "ITCM RAM", 46 .start = ITCM_OFFSET, 47 .end = ITCM_END, 48 .flags = IORESOURCE_MEM 49 }; 50 51 static struct map_desc dtcm_iomap[] __initdata = { 52 { 53 .virtual = DTCM_OFFSET, 54 .pfn = __phys_to_pfn(DTCM_OFFSET), 55 .length = (DTCM_END - DTCM_OFFSET + 1), 56 .type = MT_UNCACHED 57 } 58 }; 59 60 static struct map_desc itcm_iomap[] __initdata = { 61 { 62 .virtual = ITCM_OFFSET, 63 .pfn = __phys_to_pfn(ITCM_OFFSET), 64 .length = (ITCM_END - ITCM_OFFSET + 1), 65 .type = MT_UNCACHED 66 } 67 }; 68 69 /* 70 * Allocate a chunk of TCM memory 71 */ 72 void *tcm_alloc(size_t len) 73 { 74 unsigned long vaddr; 75 76 if (!tcm_pool) 77 return NULL; 78 79 vaddr = gen_pool_alloc(tcm_pool, len); 80 if (!vaddr) 81 return NULL; 82 83 return (void *) vaddr; 84 } 85 EXPORT_SYMBOL(tcm_alloc); 86 87 /* 88 * Free a chunk of TCM memory 89 */ 90 void tcm_free(void *addr, size_t len) 91 { 92 gen_pool_free(tcm_pool, (unsigned long) addr, len); 93 } 94 EXPORT_SYMBOL(tcm_free); 95 96 97 static void __init setup_tcm_bank(u8 type, u32 offset, u32 expected_size) 98 { 99 const int tcm_sizes[16] = { 0, -1, -1, 4, 8, 16, 32, 64, 128, 100 256, 512, 1024, -1, -1, -1, -1 }; 101 u32 tcm_region; 102 int tcm_size; 103 104 /* Read the special TCM region register c9, 0 */ 105 if (!type) 106 asm("mrc p15, 0, %0, c9, c1, 0" 107 : "=r" (tcm_region)); 108 else 109 asm("mrc p15, 0, %0, c9, c1, 1" 110 : "=r" (tcm_region)); 111 112 tcm_size = tcm_sizes[(tcm_region >> 2) & 0x0f]; 113 if (tcm_size < 0) { 114 pr_err("CPU: %sTCM of unknown size!\n", 115 type ? "I" : "D"); 116 } else { 117 pr_info("CPU: found %sTCM %dk @ %08x, %senabled\n", 118 type ? "I" : "D", 119 tcm_size, 120 (tcm_region & 0xfffff000U), 121 (tcm_region & 1) ? "" : "not "); 122 } 123 124 if (tcm_size != expected_size) { 125 pr_crit("CPU: %sTCM was detected %dk but expected %dk!\n", 126 type ? "I" : "D", 127 tcm_size, 128 expected_size); 129 /* Adjust to the expected size? what can we do... */ 130 } 131 132 /* Force move the TCM bank to where we want it, enable */ 133 tcm_region = offset | (tcm_region & 0x00000ffeU) | 1; 134 135 if (!type) 136 asm("mcr p15, 0, %0, c9, c1, 0" 137 : /* No output operands */ 138 : "r" (tcm_region)); 139 else 140 asm("mcr p15, 0, %0, c9, c1, 1" 141 : /* No output operands */ 142 : "r" (tcm_region)); 143 144 pr_debug("CPU: moved %sTCM %dk to %08x, enabled\n", 145 type ? "I" : "D", 146 tcm_size, 147 (tcm_region & 0xfffff000U)); 148 } 149 150 /* 151 * This initializes the TCM memory 152 */ 153 void __init tcm_init(void) 154 { 155 u32 tcm_status = read_cpuid_tcmstatus(); 156 char *start; 157 char *end; 158 char *ram; 159 160 /* Setup DTCM if present */ 161 if (tcm_status & (1 << 16)) { 162 setup_tcm_bank(0, DTCM_OFFSET, 163 (DTCM_END - DTCM_OFFSET + 1) >> 10); 164 request_resource(&iomem_resource, &dtcm_res); 165 iotable_init(dtcm_iomap, 1); 166 /* Copy data from RAM to DTCM */ 167 start = &__sdtcm_data; 168 end = &__edtcm_data; 169 ram = &__dtcm_start; 170 memcpy(start, ram, (end-start)); 171 pr_debug("CPU DTCM: copied data from %p - %p\n", start, end); 172 } 173 174 /* Setup ITCM if present */ 175 if (tcm_status & 1) { 176 setup_tcm_bank(1, ITCM_OFFSET, 177 (ITCM_END - ITCM_OFFSET + 1) >> 10); 178 request_resource(&iomem_resource, &itcm_res); 179 iotable_init(itcm_iomap, 1); 180 /* Copy code from RAM to ITCM */ 181 start = &__sitcm_text; 182 end = &__eitcm_text; 183 ram = &__itcm_start; 184 memcpy(start, ram, (end-start)); 185 pr_debug("CPU ITCM: copied code from %p - %p\n", start, end); 186 } 187 } 188 189 /* 190 * This creates the TCM memory pool and has to be done later, 191 * during the core_initicalls, since the allocator is not yet 192 * up and running when the first initialization runs. 193 */ 194 static int __init setup_tcm_pool(void) 195 { 196 u32 tcm_status = read_cpuid_tcmstatus(); 197 u32 dtcm_pool_start = (u32) &__edtcm_data; 198 u32 itcm_pool_start = (u32) &__eitcm_text; 199 int ret; 200 201 /* 202 * Set up malloc pool, 2^2 = 4 bytes granularity since 203 * the TCM is sometimes just 4 KiB. NB: pages and cache 204 * line alignments does not matter in TCM! 205 */ 206 tcm_pool = gen_pool_create(2, -1); 207 208 pr_debug("Setting up TCM memory pool\n"); 209 210 /* Add the rest of DTCM to the TCM pool */ 211 if (tcm_status & (1 << 16)) { 212 if (dtcm_pool_start < DTCM_END) { 213 ret = gen_pool_add(tcm_pool, dtcm_pool_start, 214 DTCM_END - dtcm_pool_start + 1, -1); 215 if (ret) { 216 pr_err("CPU DTCM: could not add DTCM " \ 217 "remainder to pool!\n"); 218 return ret; 219 } 220 pr_debug("CPU DTCM: Added %08x bytes @ %08x to " \ 221 "the TCM memory pool\n", 222 DTCM_END - dtcm_pool_start + 1, 223 dtcm_pool_start); 224 } 225 } 226 227 /* Add the rest of ITCM to the TCM pool */ 228 if (tcm_status & 1) { 229 if (itcm_pool_start < ITCM_END) { 230 ret = gen_pool_add(tcm_pool, itcm_pool_start, 231 ITCM_END - itcm_pool_start + 1, -1); 232 if (ret) { 233 pr_err("CPU ITCM: could not add ITCM " \ 234 "remainder to pool!\n"); 235 return ret; 236 } 237 pr_debug("CPU ITCM: Added %08x bytes @ %08x to " \ 238 "the TCM memory pool\n", 239 ITCM_END - itcm_pool_start + 1, 240 itcm_pool_start); 241 } 242 } 243 return 0; 244 } 245 246 core_initcall(setup_tcm_pool); 247