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 #include <asm/traps.h> 21 22 #define TCMTR_FORMAT_MASK 0xe0000000U 23 24 static struct gen_pool *tcm_pool; 25 static bool dtcm_present; 26 static bool itcm_present; 27 28 /* TCM section definitions from the linker */ 29 extern char __itcm_start, __sitcm_text, __eitcm_text; 30 extern char __dtcm_start, __sdtcm_data, __edtcm_data; 31 32 /* These will be increased as we run */ 33 u32 dtcm_end = DTCM_OFFSET; 34 u32 itcm_end = ITCM_OFFSET; 35 36 /* 37 * TCM memory resources 38 */ 39 static struct resource dtcm_res = { 40 .name = "DTCM RAM", 41 .start = DTCM_OFFSET, 42 .end = DTCM_OFFSET, 43 .flags = IORESOURCE_MEM 44 }; 45 46 static struct resource itcm_res = { 47 .name = "ITCM RAM", 48 .start = ITCM_OFFSET, 49 .end = ITCM_OFFSET, 50 .flags = IORESOURCE_MEM 51 }; 52 53 static struct map_desc dtcm_iomap[] __initdata = { 54 { 55 .virtual = DTCM_OFFSET, 56 .pfn = __phys_to_pfn(DTCM_OFFSET), 57 .length = 0, 58 .type = MT_MEMORY_RW_DTCM 59 } 60 }; 61 62 static struct map_desc itcm_iomap[] __initdata = { 63 { 64 .virtual = ITCM_OFFSET, 65 .pfn = __phys_to_pfn(ITCM_OFFSET), 66 .length = 0, 67 .type = MT_MEMORY_RWX_ITCM, 68 } 69 }; 70 71 /* 72 * Allocate a chunk of TCM memory 73 */ 74 void *tcm_alloc(size_t len) 75 { 76 unsigned long vaddr; 77 78 if (!tcm_pool) 79 return NULL; 80 81 vaddr = gen_pool_alloc(tcm_pool, len); 82 if (!vaddr) 83 return NULL; 84 85 return (void *) vaddr; 86 } 87 EXPORT_SYMBOL(tcm_alloc); 88 89 /* 90 * Free a chunk of TCM memory 91 */ 92 void tcm_free(void *addr, size_t len) 93 { 94 gen_pool_free(tcm_pool, (unsigned long) addr, len); 95 } 96 EXPORT_SYMBOL(tcm_free); 97 98 bool tcm_dtcm_present(void) 99 { 100 return dtcm_present; 101 } 102 EXPORT_SYMBOL(tcm_dtcm_present); 103 104 bool tcm_itcm_present(void) 105 { 106 return itcm_present; 107 } 108 EXPORT_SYMBOL(tcm_itcm_present); 109 110 static int __init setup_tcm_bank(u8 type, u8 bank, u8 banks, 111 u32 *offset) 112 { 113 const int tcm_sizes[16] = { 0, -1, -1, 4, 8, 16, 32, 64, 128, 114 256, 512, 1024, -1, -1, -1, -1 }; 115 u32 tcm_region; 116 int tcm_size; 117 118 /* 119 * If there are more than one TCM bank of this type, 120 * select the TCM bank to operate on in the TCM selection 121 * register. 122 */ 123 if (banks > 1) 124 asm("mcr p15, 0, %0, c9, c2, 0" 125 : /* No output operands */ 126 : "r" (bank)); 127 128 /* Read the special TCM region register c9, 0 */ 129 if (!type) 130 asm("mrc p15, 0, %0, c9, c1, 0" 131 : "=r" (tcm_region)); 132 else 133 asm("mrc p15, 0, %0, c9, c1, 1" 134 : "=r" (tcm_region)); 135 136 tcm_size = tcm_sizes[(tcm_region >> 2) & 0x0f]; 137 if (tcm_size < 0) { 138 pr_err("CPU: %sTCM%d of unknown size\n", 139 type ? "I" : "D", bank); 140 return -EINVAL; 141 } else if (tcm_size > 32) { 142 pr_err("CPU: %sTCM%d larger than 32k found\n", 143 type ? "I" : "D", bank); 144 return -EINVAL; 145 } else { 146 pr_info("CPU: found %sTCM%d %dk @ %08x, %senabled\n", 147 type ? "I" : "D", 148 bank, 149 tcm_size, 150 (tcm_region & 0xfffff000U), 151 (tcm_region & 1) ? "" : "not "); 152 } 153 154 /* Not much fun you can do with a size 0 bank */ 155 if (tcm_size == 0) 156 return 0; 157 158 /* Force move the TCM bank to where we want it, enable */ 159 tcm_region = *offset | (tcm_region & 0x00000ffeU) | 1; 160 161 if (!type) 162 asm("mcr p15, 0, %0, c9, c1, 0" 163 : /* No output operands */ 164 : "r" (tcm_region)); 165 else 166 asm("mcr p15, 0, %0, c9, c1, 1" 167 : /* No output operands */ 168 : "r" (tcm_region)); 169 170 /* Increase offset */ 171 *offset += (tcm_size << 10); 172 173 pr_info("CPU: moved %sTCM%d %dk to %08x, enabled\n", 174 type ? "I" : "D", 175 bank, 176 tcm_size, 177 (tcm_region & 0xfffff000U)); 178 return 0; 179 } 180 181 /* 182 * When we are running in the non-secure world and the secure world 183 * has not explicitly given us access to the TCM we will get an 184 * undefined error when reading the TCM region register in the 185 * setup_tcm_bank function (above). 186 * 187 * There are two variants of this register read that we need to trap, 188 * the read for the data TCM and the read for the instruction TCM: 189 * c0370628: ee196f11 mrc 15, 0, r6, cr9, cr1, {0} 190 * c0370674: ee196f31 mrc 15, 0, r6, cr9, cr1, {1} 191 * 192 * Our undef hook mask explicitly matches all fields of the encoded 193 * instruction other than the destination register. The mask also 194 * only allows operand 2 to have the values 0 or 1. 195 * 196 * The undefined hook is defined as __init and __initdata, and therefore 197 * must be removed before tcm_init returns. 198 * 199 * In this particular case (MRC with ARM condition code ALways) the 200 * Thumb-2 and ARM instruction encoding are identical, so this hook 201 * will work on a Thumb-2 kernel. 202 * 203 * See A8.8.107, DDI0406C_C ARM Architecture Reference Manual, Encoding 204 * T1/A1 for the bit-by-bit details. 205 * 206 * mrc p15, 0, XX, c9, c1, 0 207 * mrc p15, 0, XX, c9, c1, 1 208 * | | | | | | | +---- opc2 0|1 = 000|001 209 * | | | | | | +------- CRm 0 = 0001 210 * | | | | | +----------- CRn 0 = 1001 211 * | | | | +--------------- Rt ? = ???? 212 * | | | +------------------- opc1 0 = 000 213 * | | +----------------------- coproc 15 = 1111 214 * | +-------------------------- condition ALways = 1110 215 * +----------------------------- instruction MRC = 1110 216 * 217 * Encoding this as per A8.8.107 of DDI0406C, Encoding T1/A1, yields: 218 * 1111 1111 1111 1111 0000 1111 1101 1111 Required Mask 219 * 1110 1110 0001 1001 ???? 1111 0001 0001 mrc p15, 0, XX, c9, c1, 0 220 * 1110 1110 0001 1001 ???? 1111 0011 0001 mrc p15, 0, XX, c9, c1, 1 221 * [ ] [ ] [ ]| [ ] [ ] [ ] [ ]| +--- CRm 222 * | | | | | | | | +----- SBO 223 * | | | | | | | +------- opc2 224 * | | | | | | +----------- coproc 225 * | | | | | +---------------- Rt 226 * | | | | +--------------------- CRn 227 * | | | +------------------------- SBO 228 * | | +--------------------------- opc1 229 * | +------------------------------- instruction 230 * +------------------------------------ condition 231 */ 232 #define TCM_REGION_READ_MASK 0xffff0fdf 233 #define TCM_REGION_READ_INSTR 0xee190f11 234 #define DEST_REG_SHIFT 12 235 #define DEST_REG_MASK 0xf 236 237 static int __init tcm_handler(struct pt_regs *regs, unsigned int instr) 238 { 239 regs->uregs[(instr >> DEST_REG_SHIFT) & DEST_REG_MASK] = 0; 240 regs->ARM_pc += 4; 241 return 0; 242 } 243 244 static struct undef_hook tcm_hook __initdata = { 245 .instr_mask = TCM_REGION_READ_MASK, 246 .instr_val = TCM_REGION_READ_INSTR, 247 .cpsr_mask = MODE_MASK, 248 .cpsr_val = SVC_MODE, 249 .fn = tcm_handler 250 }; 251 252 /* 253 * This initializes the TCM memory 254 */ 255 void __init tcm_init(void) 256 { 257 u32 tcm_status; 258 u8 dtcm_banks; 259 u8 itcm_banks; 260 size_t dtcm_code_sz = &__edtcm_data - &__sdtcm_data; 261 size_t itcm_code_sz = &__eitcm_text - &__sitcm_text; 262 char *start; 263 char *end; 264 char *ram; 265 int ret; 266 int i; 267 268 /* 269 * Prior to ARMv5 there is no TCM, and trying to read the status 270 * register will hang the processor. 271 */ 272 if (cpu_architecture() < CPU_ARCH_ARMv5) { 273 if (dtcm_code_sz || itcm_code_sz) 274 pr_info("CPU TCM: %u bytes of DTCM and %u bytes of " 275 "ITCM code compiled in, but no TCM present " 276 "in pre-v5 CPU\n", dtcm_code_sz, itcm_code_sz); 277 return; 278 } 279 280 tcm_status = read_cpuid_tcmstatus(); 281 282 /* 283 * This code only supports v6-compatible TCMTR implementations. 284 */ 285 if (tcm_status & TCMTR_FORMAT_MASK) 286 return; 287 288 dtcm_banks = (tcm_status >> 16) & 0x03; 289 itcm_banks = (tcm_status & 0x03); 290 291 register_undef_hook(&tcm_hook); 292 293 /* Values greater than 2 for D/ITCM banks are "reserved" */ 294 if (dtcm_banks > 2) 295 dtcm_banks = 0; 296 if (itcm_banks > 2) 297 itcm_banks = 0; 298 299 /* Setup DTCM if present */ 300 if (dtcm_banks > 0) { 301 for (i = 0; i < dtcm_banks; i++) { 302 ret = setup_tcm_bank(0, i, dtcm_banks, &dtcm_end); 303 if (ret) 304 goto unregister; 305 } 306 /* This means you compiled more code than fits into DTCM */ 307 if (dtcm_code_sz > (dtcm_end - DTCM_OFFSET)) { 308 pr_info("CPU DTCM: %u bytes of code compiled to " 309 "DTCM but only %lu bytes of DTCM present\n", 310 dtcm_code_sz, (dtcm_end - DTCM_OFFSET)); 311 goto no_dtcm; 312 } 313 /* 314 * This means that the DTCM sizes were 0 or the DTCM banks 315 * were inaccessible due to TrustZone configuration. 316 */ 317 if (!(dtcm_end - DTCM_OFFSET)) 318 goto no_dtcm; 319 dtcm_res.end = dtcm_end - 1; 320 request_resource(&iomem_resource, &dtcm_res); 321 dtcm_iomap[0].length = dtcm_end - DTCM_OFFSET; 322 iotable_init(dtcm_iomap, 1); 323 /* Copy data from RAM to DTCM */ 324 start = &__sdtcm_data; 325 end = &__edtcm_data; 326 ram = &__dtcm_start; 327 memcpy(start, ram, dtcm_code_sz); 328 pr_debug("CPU DTCM: copied data from %p - %p\n", 329 start, end); 330 dtcm_present = true; 331 } else if (dtcm_code_sz) { 332 pr_info("CPU DTCM: %u bytes of code compiled to DTCM but no " 333 "DTCM banks present in CPU\n", dtcm_code_sz); 334 } 335 336 no_dtcm: 337 /* Setup ITCM if present */ 338 if (itcm_banks > 0) { 339 for (i = 0; i < itcm_banks; i++) { 340 ret = setup_tcm_bank(1, i, itcm_banks, &itcm_end); 341 if (ret) 342 goto unregister; 343 } 344 /* This means you compiled more code than fits into ITCM */ 345 if (itcm_code_sz > (itcm_end - ITCM_OFFSET)) { 346 pr_info("CPU ITCM: %u bytes of code compiled to " 347 "ITCM but only %lu bytes of ITCM present\n", 348 itcm_code_sz, (itcm_end - ITCM_OFFSET)); 349 goto unregister; 350 } 351 /* 352 * This means that the ITCM sizes were 0 or the ITCM banks 353 * were inaccessible due to TrustZone configuration. 354 */ 355 if (!(itcm_end - ITCM_OFFSET)) 356 goto unregister; 357 itcm_res.end = itcm_end - 1; 358 request_resource(&iomem_resource, &itcm_res); 359 itcm_iomap[0].length = itcm_end - ITCM_OFFSET; 360 iotable_init(itcm_iomap, 1); 361 /* Copy code from RAM to ITCM */ 362 start = &__sitcm_text; 363 end = &__eitcm_text; 364 ram = &__itcm_start; 365 memcpy(start, ram, itcm_code_sz); 366 pr_debug("CPU ITCM: copied code from %p - %p\n", 367 start, end); 368 itcm_present = true; 369 } else if (itcm_code_sz) { 370 pr_info("CPU ITCM: %u bytes of code compiled to ITCM but no " 371 "ITCM banks present in CPU\n", itcm_code_sz); 372 } 373 374 unregister: 375 unregister_undef_hook(&tcm_hook); 376 } 377 378 /* 379 * This creates the TCM memory pool and has to be done later, 380 * during the core_initicalls, since the allocator is not yet 381 * up and running when the first initialization runs. 382 */ 383 static int __init setup_tcm_pool(void) 384 { 385 u32 dtcm_pool_start = (u32) &__edtcm_data; 386 u32 itcm_pool_start = (u32) &__eitcm_text; 387 int ret; 388 389 /* 390 * Set up malloc pool, 2^2 = 4 bytes granularity since 391 * the TCM is sometimes just 4 KiB. NB: pages and cache 392 * line alignments does not matter in TCM! 393 */ 394 tcm_pool = gen_pool_create(2, -1); 395 396 pr_debug("Setting up TCM memory pool\n"); 397 398 /* Add the rest of DTCM to the TCM pool */ 399 if (dtcm_present) { 400 if (dtcm_pool_start < dtcm_end) { 401 ret = gen_pool_add(tcm_pool, dtcm_pool_start, 402 dtcm_end - dtcm_pool_start, -1); 403 if (ret) { 404 pr_err("CPU DTCM: could not add DTCM " \ 405 "remainder to pool!\n"); 406 return ret; 407 } 408 pr_debug("CPU DTCM: Added %08x bytes @ %08x to " \ 409 "the TCM memory pool\n", 410 dtcm_end - dtcm_pool_start, 411 dtcm_pool_start); 412 } 413 } 414 415 /* Add the rest of ITCM to the TCM pool */ 416 if (itcm_present) { 417 if (itcm_pool_start < itcm_end) { 418 ret = gen_pool_add(tcm_pool, itcm_pool_start, 419 itcm_end - itcm_pool_start, -1); 420 if (ret) { 421 pr_err("CPU ITCM: could not add ITCM " \ 422 "remainder to pool!\n"); 423 return ret; 424 } 425 pr_debug("CPU ITCM: Added %08x bytes @ %08x to " \ 426 "the TCM memory pool\n", 427 itcm_end - itcm_pool_start, 428 itcm_pool_start); 429 } 430 } 431 return 0; 432 } 433 434 core_initcall(setup_tcm_pool); 435