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/cputype.h> 17 #include <asm/mach/map.h> 18 #include <asm/memory.h> 19 #include <asm/system_info.h> 20 21 static struct gen_pool *tcm_pool; 22 static bool dtcm_present; 23 static bool itcm_present; 24 25 /* TCM section definitions from the linker */ 26 extern char __itcm_start, __sitcm_text, __eitcm_text; 27 extern char __dtcm_start, __sdtcm_data, __edtcm_data; 28 29 /* These will be increased as we run */ 30 u32 dtcm_end = DTCM_OFFSET; 31 u32 itcm_end = ITCM_OFFSET; 32 33 /* 34 * TCM memory resources 35 */ 36 static struct resource dtcm_res = { 37 .name = "DTCM RAM", 38 .start = DTCM_OFFSET, 39 .end = DTCM_OFFSET, 40 .flags = IORESOURCE_MEM 41 }; 42 43 static struct resource itcm_res = { 44 .name = "ITCM RAM", 45 .start = ITCM_OFFSET, 46 .end = ITCM_OFFSET, 47 .flags = IORESOURCE_MEM 48 }; 49 50 static struct map_desc dtcm_iomap[] __initdata = { 51 { 52 .virtual = DTCM_OFFSET, 53 .pfn = __phys_to_pfn(DTCM_OFFSET), 54 .length = 0, 55 .type = MT_MEMORY_RW_DTCM 56 } 57 }; 58 59 static struct map_desc itcm_iomap[] __initdata = { 60 { 61 .virtual = ITCM_OFFSET, 62 .pfn = __phys_to_pfn(ITCM_OFFSET), 63 .length = 0, 64 .type = MT_MEMORY_RWX_ITCM, 65 } 66 }; 67 68 /* 69 * Allocate a chunk of TCM memory 70 */ 71 void *tcm_alloc(size_t len) 72 { 73 unsigned long vaddr; 74 75 if (!tcm_pool) 76 return NULL; 77 78 vaddr = gen_pool_alloc(tcm_pool, len); 79 if (!vaddr) 80 return NULL; 81 82 return (void *) vaddr; 83 } 84 EXPORT_SYMBOL(tcm_alloc); 85 86 /* 87 * Free a chunk of TCM memory 88 */ 89 void tcm_free(void *addr, size_t len) 90 { 91 gen_pool_free(tcm_pool, (unsigned long) addr, len); 92 } 93 EXPORT_SYMBOL(tcm_free); 94 95 bool tcm_dtcm_present(void) 96 { 97 return dtcm_present; 98 } 99 EXPORT_SYMBOL(tcm_dtcm_present); 100 101 bool tcm_itcm_present(void) 102 { 103 return itcm_present; 104 } 105 EXPORT_SYMBOL(tcm_itcm_present); 106 107 static int __init setup_tcm_bank(u8 type, u8 bank, u8 banks, 108 u32 *offset) 109 { 110 const int tcm_sizes[16] = { 0, -1, -1, 4, 8, 16, 32, 64, 128, 111 256, 512, 1024, -1, -1, -1, -1 }; 112 u32 tcm_region; 113 int tcm_size; 114 115 /* 116 * If there are more than one TCM bank of this type, 117 * select the TCM bank to operate on in the TCM selection 118 * register. 119 */ 120 if (banks > 1) 121 asm("mcr p15, 0, %0, c9, c2, 0" 122 : /* No output operands */ 123 : "r" (bank)); 124 125 /* Read the special TCM region register c9, 0 */ 126 if (!type) 127 asm("mrc p15, 0, %0, c9, c1, 0" 128 : "=r" (tcm_region)); 129 else 130 asm("mrc p15, 0, %0, c9, c1, 1" 131 : "=r" (tcm_region)); 132 133 tcm_size = tcm_sizes[(tcm_region >> 2) & 0x0f]; 134 if (tcm_size < 0) { 135 pr_err("CPU: %sTCM%d of unknown size\n", 136 type ? "I" : "D", bank); 137 return -EINVAL; 138 } else if (tcm_size > 32) { 139 pr_err("CPU: %sTCM%d larger than 32k found\n", 140 type ? "I" : "D", bank); 141 return -EINVAL; 142 } else { 143 pr_info("CPU: found %sTCM%d %dk @ %08x, %senabled\n", 144 type ? "I" : "D", 145 bank, 146 tcm_size, 147 (tcm_region & 0xfffff000U), 148 (tcm_region & 1) ? "" : "not "); 149 } 150 151 /* Not much fun you can do with a size 0 bank */ 152 if (tcm_size == 0) 153 return 0; 154 155 /* Force move the TCM bank to where we want it, enable */ 156 tcm_region = *offset | (tcm_region & 0x00000ffeU) | 1; 157 158 if (!type) 159 asm("mcr p15, 0, %0, c9, c1, 0" 160 : /* No output operands */ 161 : "r" (tcm_region)); 162 else 163 asm("mcr p15, 0, %0, c9, c1, 1" 164 : /* No output operands */ 165 : "r" (tcm_region)); 166 167 /* Increase offset */ 168 *offset += (tcm_size << 10); 169 170 pr_info("CPU: moved %sTCM%d %dk to %08x, enabled\n", 171 type ? "I" : "D", 172 bank, 173 tcm_size, 174 (tcm_region & 0xfffff000U)); 175 return 0; 176 } 177 178 /* 179 * This initializes the TCM memory 180 */ 181 void __init tcm_init(void) 182 { 183 u32 tcm_status; 184 u8 dtcm_banks; 185 u8 itcm_banks; 186 size_t dtcm_code_sz = &__edtcm_data - &__sdtcm_data; 187 size_t itcm_code_sz = &__eitcm_text - &__sitcm_text; 188 char *start; 189 char *end; 190 char *ram; 191 int ret; 192 int i; 193 194 /* 195 * Prior to ARMv5 there is no TCM, and trying to read the status 196 * register will hang the processor. 197 */ 198 if (cpu_architecture() < CPU_ARCH_ARMv5) { 199 if (dtcm_code_sz || itcm_code_sz) 200 pr_info("CPU TCM: %u bytes of DTCM and %u bytes of " 201 "ITCM code compiled in, but no TCM present " 202 "in pre-v5 CPU\n", dtcm_code_sz, itcm_code_sz); 203 return; 204 } 205 206 tcm_status = read_cpuid_tcmstatus(); 207 dtcm_banks = (tcm_status >> 16) & 0x03; 208 itcm_banks = (tcm_status & 0x03); 209 210 /* Values greater than 2 for D/ITCM banks are "reserved" */ 211 if (dtcm_banks > 2) 212 dtcm_banks = 0; 213 if (itcm_banks > 2) 214 itcm_banks = 0; 215 216 /* Setup DTCM if present */ 217 if (dtcm_banks > 0) { 218 for (i = 0; i < dtcm_banks; i++) { 219 ret = setup_tcm_bank(0, i, dtcm_banks, &dtcm_end); 220 if (ret) 221 return; 222 } 223 /* This means you compiled more code than fits into DTCM */ 224 if (dtcm_code_sz > (dtcm_end - DTCM_OFFSET)) { 225 pr_info("CPU DTCM: %u bytes of code compiled to " 226 "DTCM but only %lu bytes of DTCM present\n", 227 dtcm_code_sz, (dtcm_end - DTCM_OFFSET)); 228 goto no_dtcm; 229 } 230 dtcm_res.end = dtcm_end - 1; 231 request_resource(&iomem_resource, &dtcm_res); 232 dtcm_iomap[0].length = dtcm_end - DTCM_OFFSET; 233 iotable_init(dtcm_iomap, 1); 234 /* Copy data from RAM to DTCM */ 235 start = &__sdtcm_data; 236 end = &__edtcm_data; 237 ram = &__dtcm_start; 238 memcpy(start, ram, dtcm_code_sz); 239 pr_debug("CPU DTCM: copied data from %p - %p\n", 240 start, end); 241 dtcm_present = true; 242 } else if (dtcm_code_sz) { 243 pr_info("CPU DTCM: %u bytes of code compiled to DTCM but no " 244 "DTCM banks present in CPU\n", dtcm_code_sz); 245 } 246 247 no_dtcm: 248 /* Setup ITCM if present */ 249 if (itcm_banks > 0) { 250 for (i = 0; i < itcm_banks; i++) { 251 ret = setup_tcm_bank(1, i, itcm_banks, &itcm_end); 252 if (ret) 253 return; 254 } 255 /* This means you compiled more code than fits into ITCM */ 256 if (itcm_code_sz > (itcm_end - ITCM_OFFSET)) { 257 pr_info("CPU ITCM: %u bytes of code compiled to " 258 "ITCM but only %lu bytes of ITCM present\n", 259 itcm_code_sz, (itcm_end - ITCM_OFFSET)); 260 return; 261 } 262 itcm_res.end = itcm_end - 1; 263 request_resource(&iomem_resource, &itcm_res); 264 itcm_iomap[0].length = itcm_end - ITCM_OFFSET; 265 iotable_init(itcm_iomap, 1); 266 /* Copy code from RAM to ITCM */ 267 start = &__sitcm_text; 268 end = &__eitcm_text; 269 ram = &__itcm_start; 270 memcpy(start, ram, itcm_code_sz); 271 pr_debug("CPU ITCM: copied code from %p - %p\n", 272 start, end); 273 itcm_present = true; 274 } else if (itcm_code_sz) { 275 pr_info("CPU ITCM: %u bytes of code compiled to ITCM but no " 276 "ITCM banks present in CPU\n", itcm_code_sz); 277 } 278 } 279 280 /* 281 * This creates the TCM memory pool and has to be done later, 282 * during the core_initicalls, since the allocator is not yet 283 * up and running when the first initialization runs. 284 */ 285 static int __init setup_tcm_pool(void) 286 { 287 u32 dtcm_pool_start = (u32) &__edtcm_data; 288 u32 itcm_pool_start = (u32) &__eitcm_text; 289 int ret; 290 291 /* 292 * Set up malloc pool, 2^2 = 4 bytes granularity since 293 * the TCM is sometimes just 4 KiB. NB: pages and cache 294 * line alignments does not matter in TCM! 295 */ 296 tcm_pool = gen_pool_create(2, -1); 297 298 pr_debug("Setting up TCM memory pool\n"); 299 300 /* Add the rest of DTCM to the TCM pool */ 301 if (dtcm_present) { 302 if (dtcm_pool_start < dtcm_end) { 303 ret = gen_pool_add(tcm_pool, dtcm_pool_start, 304 dtcm_end - dtcm_pool_start, -1); 305 if (ret) { 306 pr_err("CPU DTCM: could not add DTCM " \ 307 "remainder to pool!\n"); 308 return ret; 309 } 310 pr_debug("CPU DTCM: Added %08x bytes @ %08x to " \ 311 "the TCM memory pool\n", 312 dtcm_end - dtcm_pool_start, 313 dtcm_pool_start); 314 } 315 } 316 317 /* Add the rest of ITCM to the TCM pool */ 318 if (itcm_present) { 319 if (itcm_pool_start < itcm_end) { 320 ret = gen_pool_add(tcm_pool, itcm_pool_start, 321 itcm_end - itcm_pool_start, -1); 322 if (ret) { 323 pr_err("CPU ITCM: could not add ITCM " \ 324 "remainder to pool!\n"); 325 return ret; 326 } 327 pr_debug("CPU ITCM: Added %08x bytes @ %08x to " \ 328 "the TCM memory pool\n", 329 itcm_end - itcm_pool_start, 330 itcm_pool_start); 331 } 332 } 333 return 0; 334 } 335 336 core_initcall(setup_tcm_pool); 337