1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Generic on-chip SRAM allocation driver 4 * 5 * Copyright (C) 2012 Philipp Zabel, Pengutronix 6 */ 7 8 #include <linux/clk.h> 9 #include <linux/delay.h> 10 #include <linux/genalloc.h> 11 #include <linux/io.h> 12 #include <linux/list_sort.h> 13 #include <linux/of_address.h> 14 #include <linux/of_device.h> 15 #include <linux/platform_device.h> 16 #include <linux/regmap.h> 17 #include <linux/slab.h> 18 #include <linux/mfd/syscon.h> 19 #include <soc/at91/atmel-secumod.h> 20 21 #include "sram.h" 22 23 #define SRAM_GRANULARITY 32 24 25 static ssize_t sram_read(struct file *filp, struct kobject *kobj, 26 struct bin_attribute *attr, 27 char *buf, loff_t pos, size_t count) 28 { 29 struct sram_partition *part; 30 31 part = container_of(attr, struct sram_partition, battr); 32 33 mutex_lock(&part->lock); 34 memcpy_fromio(buf, part->base + pos, count); 35 mutex_unlock(&part->lock); 36 37 return count; 38 } 39 40 static ssize_t sram_write(struct file *filp, struct kobject *kobj, 41 struct bin_attribute *attr, 42 char *buf, loff_t pos, size_t count) 43 { 44 struct sram_partition *part; 45 46 part = container_of(attr, struct sram_partition, battr); 47 48 mutex_lock(&part->lock); 49 memcpy_toio(part->base + pos, buf, count); 50 mutex_unlock(&part->lock); 51 52 return count; 53 } 54 55 static int sram_add_pool(struct sram_dev *sram, struct sram_reserve *block, 56 phys_addr_t start, struct sram_partition *part) 57 { 58 int ret; 59 60 part->pool = devm_gen_pool_create(sram->dev, ilog2(SRAM_GRANULARITY), 61 NUMA_NO_NODE, block->label); 62 if (IS_ERR(part->pool)) 63 return PTR_ERR(part->pool); 64 65 ret = gen_pool_add_virt(part->pool, (unsigned long)part->base, start, 66 block->size, NUMA_NO_NODE); 67 if (ret < 0) { 68 dev_err(sram->dev, "failed to register subpool: %d\n", ret); 69 return ret; 70 } 71 72 return 0; 73 } 74 75 static int sram_add_export(struct sram_dev *sram, struct sram_reserve *block, 76 phys_addr_t start, struct sram_partition *part) 77 { 78 sysfs_bin_attr_init(&part->battr); 79 part->battr.attr.name = devm_kasprintf(sram->dev, GFP_KERNEL, 80 "%llx.sram", 81 (unsigned long long)start); 82 if (!part->battr.attr.name) 83 return -ENOMEM; 84 85 part->battr.attr.mode = S_IRUSR | S_IWUSR; 86 part->battr.read = sram_read; 87 part->battr.write = sram_write; 88 part->battr.size = block->size; 89 90 return device_create_bin_file(sram->dev, &part->battr); 91 } 92 93 static int sram_add_partition(struct sram_dev *sram, struct sram_reserve *block, 94 phys_addr_t start) 95 { 96 int ret; 97 struct sram_partition *part = &sram->partition[sram->partitions]; 98 99 mutex_init(&part->lock); 100 101 if (sram->config && sram->config->map_only_reserved) { 102 void __iomem *virt_base; 103 104 if (sram->no_memory_wc) 105 virt_base = devm_ioremap_resource(sram->dev, &block->res); 106 else 107 virt_base = devm_ioremap_resource_wc(sram->dev, &block->res); 108 109 if (IS_ERR(virt_base)) { 110 dev_err(sram->dev, "could not map SRAM at %pr\n", &block->res); 111 return PTR_ERR(virt_base); 112 } 113 114 part->base = virt_base; 115 } else { 116 part->base = sram->virt_base + block->start; 117 } 118 119 if (block->pool) { 120 ret = sram_add_pool(sram, block, start, part); 121 if (ret) 122 return ret; 123 } 124 if (block->export) { 125 ret = sram_add_export(sram, block, start, part); 126 if (ret) 127 return ret; 128 } 129 if (block->protect_exec) { 130 ret = sram_check_protect_exec(sram, block, part); 131 if (ret) 132 return ret; 133 134 ret = sram_add_pool(sram, block, start, part); 135 if (ret) 136 return ret; 137 138 sram_add_protect_exec(part); 139 } 140 141 sram->partitions++; 142 143 return 0; 144 } 145 146 static void sram_free_partitions(struct sram_dev *sram) 147 { 148 struct sram_partition *part; 149 150 if (!sram->partitions) 151 return; 152 153 part = &sram->partition[sram->partitions - 1]; 154 for (; sram->partitions; sram->partitions--, part--) { 155 if (part->battr.size) 156 device_remove_bin_file(sram->dev, &part->battr); 157 158 if (part->pool && 159 gen_pool_avail(part->pool) < gen_pool_size(part->pool)) 160 dev_err(sram->dev, "removed pool while SRAM allocated\n"); 161 } 162 } 163 164 static int sram_reserve_cmp(void *priv, const struct list_head *a, 165 const struct list_head *b) 166 { 167 struct sram_reserve *ra = list_entry(a, struct sram_reserve, list); 168 struct sram_reserve *rb = list_entry(b, struct sram_reserve, list); 169 170 return ra->start - rb->start; 171 } 172 173 static int sram_reserve_regions(struct sram_dev *sram, struct resource *res) 174 { 175 struct device_node *np = sram->dev->of_node, *child; 176 unsigned long size, cur_start, cur_size; 177 struct sram_reserve *rblocks, *block; 178 struct list_head reserve_list; 179 unsigned int nblocks, exports = 0; 180 const char *label; 181 int ret = 0; 182 183 INIT_LIST_HEAD(&reserve_list); 184 185 size = resource_size(res); 186 187 /* 188 * We need an additional block to mark the end of the memory region 189 * after the reserved blocks from the dt are processed. 190 */ 191 nblocks = (np) ? of_get_available_child_count(np) + 1 : 1; 192 rblocks = kcalloc(nblocks, sizeof(*rblocks), GFP_KERNEL); 193 if (!rblocks) 194 return -ENOMEM; 195 196 block = &rblocks[0]; 197 for_each_available_child_of_node(np, child) { 198 struct resource child_res; 199 200 ret = of_address_to_resource(child, 0, &child_res); 201 if (ret < 0) { 202 dev_err(sram->dev, 203 "could not get address for node %pOF\n", 204 child); 205 goto err_chunks; 206 } 207 208 if (child_res.start < res->start || child_res.end > res->end) { 209 dev_err(sram->dev, 210 "reserved block %pOF outside the sram area\n", 211 child); 212 ret = -EINVAL; 213 goto err_chunks; 214 } 215 216 block->start = child_res.start - res->start; 217 block->size = resource_size(&child_res); 218 block->res = child_res; 219 list_add_tail(&block->list, &reserve_list); 220 221 block->export = of_property_read_bool(child, "export"); 222 block->pool = of_property_read_bool(child, "pool"); 223 block->protect_exec = of_property_read_bool(child, "protect-exec"); 224 225 if ((block->export || block->pool || block->protect_exec) && 226 block->size) { 227 exports++; 228 229 label = NULL; 230 ret = of_property_read_string(child, "label", &label); 231 if (ret && ret != -EINVAL) { 232 dev_err(sram->dev, 233 "%pOF has invalid label name\n", 234 child); 235 goto err_chunks; 236 } 237 if (!label) 238 block->label = devm_kasprintf(sram->dev, GFP_KERNEL, 239 "%s", dev_name(sram->dev)); 240 else 241 block->label = devm_kstrdup(sram->dev, 242 label, GFP_KERNEL); 243 if (!block->label) { 244 ret = -ENOMEM; 245 goto err_chunks; 246 } 247 248 dev_dbg(sram->dev, "found %sblock '%s' 0x%x-0x%x\n", 249 block->export ? "exported " : "", block->label, 250 block->start, block->start + block->size); 251 } else { 252 dev_dbg(sram->dev, "found reserved block 0x%x-0x%x\n", 253 block->start, block->start + block->size); 254 } 255 256 block++; 257 } 258 child = NULL; 259 260 /* the last chunk marks the end of the region */ 261 rblocks[nblocks - 1].start = size; 262 rblocks[nblocks - 1].size = 0; 263 list_add_tail(&rblocks[nblocks - 1].list, &reserve_list); 264 265 list_sort(NULL, &reserve_list, sram_reserve_cmp); 266 267 if (exports) { 268 sram->partition = devm_kcalloc(sram->dev, 269 exports, sizeof(*sram->partition), 270 GFP_KERNEL); 271 if (!sram->partition) { 272 ret = -ENOMEM; 273 goto err_chunks; 274 } 275 } 276 277 cur_start = 0; 278 list_for_each_entry(block, &reserve_list, list) { 279 /* can only happen if sections overlap */ 280 if (block->start < cur_start) { 281 dev_err(sram->dev, 282 "block at 0x%x starts after current offset 0x%lx\n", 283 block->start, cur_start); 284 ret = -EINVAL; 285 sram_free_partitions(sram); 286 goto err_chunks; 287 } 288 289 if ((block->export || block->pool || block->protect_exec) && 290 block->size) { 291 ret = sram_add_partition(sram, block, 292 res->start + block->start); 293 if (ret) { 294 sram_free_partitions(sram); 295 goto err_chunks; 296 } 297 } 298 299 /* current start is in a reserved block, so continue after it */ 300 if (block->start == cur_start) { 301 cur_start = block->start + block->size; 302 continue; 303 } 304 305 /* 306 * allocate the space between the current starting 307 * address and the following reserved block, or the 308 * end of the region. 309 */ 310 cur_size = block->start - cur_start; 311 312 if (sram->pool) { 313 dev_dbg(sram->dev, "adding chunk 0x%lx-0x%lx\n", 314 cur_start, cur_start + cur_size); 315 316 ret = gen_pool_add_virt(sram->pool, 317 (unsigned long)sram->virt_base + cur_start, 318 res->start + cur_start, cur_size, -1); 319 if (ret < 0) { 320 sram_free_partitions(sram); 321 goto err_chunks; 322 } 323 } 324 325 /* next allocation after this reserved block */ 326 cur_start = block->start + block->size; 327 } 328 329 err_chunks: 330 of_node_put(child); 331 kfree(rblocks); 332 333 return ret; 334 } 335 336 static int atmel_securam_wait(void) 337 { 338 struct regmap *regmap; 339 u32 val; 340 341 regmap = syscon_regmap_lookup_by_compatible("atmel,sama5d2-secumod"); 342 if (IS_ERR(regmap)) 343 return -ENODEV; 344 345 return regmap_read_poll_timeout(regmap, AT91_SECUMOD_RAMRDY, val, 346 val & AT91_SECUMOD_RAMRDY_READY, 347 10000, 500000); 348 } 349 350 static const struct sram_config atmel_securam_config = { 351 .init = atmel_securam_wait, 352 }; 353 354 /* 355 * SYSRAM contains areas that are not accessible by the 356 * kernel, such as the first 256K that is reserved for TZ. 357 * Accesses to those areas (including speculative accesses) 358 * trigger SErrors. As such we must map only the areas of 359 * SYSRAM specified in the device tree. 360 */ 361 static const struct sram_config tegra_sysram_config = { 362 .map_only_reserved = true, 363 }; 364 365 static const struct of_device_id sram_dt_ids[] = { 366 { .compatible = "mmio-sram" }, 367 { .compatible = "atmel,sama5d2-securam", .data = &atmel_securam_config }, 368 { .compatible = "nvidia,tegra186-sysram", .data = &tegra_sysram_config }, 369 { .compatible = "nvidia,tegra194-sysram", .data = &tegra_sysram_config }, 370 { .compatible = "nvidia,tegra234-sysram", .data = &tegra_sysram_config }, 371 {} 372 }; 373 374 static int sram_probe(struct platform_device *pdev) 375 { 376 const struct sram_config *config; 377 struct sram_dev *sram; 378 int ret; 379 struct resource *res; 380 struct clk *clk; 381 382 config = of_device_get_match_data(&pdev->dev); 383 384 sram = devm_kzalloc(&pdev->dev, sizeof(*sram), GFP_KERNEL); 385 if (!sram) 386 return -ENOMEM; 387 388 sram->dev = &pdev->dev; 389 sram->no_memory_wc = of_property_read_bool(pdev->dev.of_node, "no-memory-wc"); 390 sram->config = config; 391 392 if (!config || !config->map_only_reserved) { 393 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 394 if (sram->no_memory_wc) 395 sram->virt_base = devm_ioremap_resource(&pdev->dev, res); 396 else 397 sram->virt_base = devm_ioremap_resource_wc(&pdev->dev, res); 398 if (IS_ERR(sram->virt_base)) { 399 dev_err(&pdev->dev, "could not map SRAM registers\n"); 400 return PTR_ERR(sram->virt_base); 401 } 402 403 sram->pool = devm_gen_pool_create(sram->dev, ilog2(SRAM_GRANULARITY), 404 NUMA_NO_NODE, NULL); 405 if (IS_ERR(sram->pool)) 406 return PTR_ERR(sram->pool); 407 } 408 409 clk = devm_clk_get_optional_enabled(sram->dev, NULL); 410 if (IS_ERR(clk)) 411 return PTR_ERR(clk); 412 413 ret = sram_reserve_regions(sram, 414 platform_get_resource(pdev, IORESOURCE_MEM, 0)); 415 if (ret) 416 return ret; 417 418 platform_set_drvdata(pdev, sram); 419 420 if (config && config->init) { 421 ret = config->init(); 422 if (ret) 423 goto err_free_partitions; 424 } 425 426 if (sram->pool) 427 dev_dbg(sram->dev, "SRAM pool: %zu KiB @ 0x%p\n", 428 gen_pool_size(sram->pool) / 1024, sram->virt_base); 429 430 return 0; 431 432 err_free_partitions: 433 sram_free_partitions(sram); 434 435 return ret; 436 } 437 438 static int sram_remove(struct platform_device *pdev) 439 { 440 struct sram_dev *sram = platform_get_drvdata(pdev); 441 442 sram_free_partitions(sram); 443 444 if (sram->pool && gen_pool_avail(sram->pool) < gen_pool_size(sram->pool)) 445 dev_err(sram->dev, "removed while SRAM allocated\n"); 446 447 return 0; 448 } 449 450 static struct platform_driver sram_driver = { 451 .driver = { 452 .name = "sram", 453 .of_match_table = sram_dt_ids, 454 }, 455 .probe = sram_probe, 456 .remove = sram_remove, 457 }; 458 459 static int __init sram_init(void) 460 { 461 return platform_driver_register(&sram_driver); 462 } 463 464 postcore_initcall(sram_init); 465