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 part->base = sram->virt_base + block->start; 101 102 if (block->pool) { 103 ret = sram_add_pool(sram, block, start, part); 104 if (ret) 105 return ret; 106 } 107 if (block->export) { 108 ret = sram_add_export(sram, block, start, part); 109 if (ret) 110 return ret; 111 } 112 if (block->protect_exec) { 113 ret = sram_check_protect_exec(sram, block, part); 114 if (ret) 115 return ret; 116 117 ret = sram_add_pool(sram, block, start, part); 118 if (ret) 119 return ret; 120 121 sram_add_protect_exec(part); 122 } 123 124 sram->partitions++; 125 126 return 0; 127 } 128 129 static void sram_free_partitions(struct sram_dev *sram) 130 { 131 struct sram_partition *part; 132 133 if (!sram->partitions) 134 return; 135 136 part = &sram->partition[sram->partitions - 1]; 137 for (; sram->partitions; sram->partitions--, part--) { 138 if (part->battr.size) 139 device_remove_bin_file(sram->dev, &part->battr); 140 141 if (part->pool && 142 gen_pool_avail(part->pool) < gen_pool_size(part->pool)) 143 dev_err(sram->dev, "removed pool while SRAM allocated\n"); 144 } 145 } 146 147 static int sram_reserve_cmp(void *priv, struct list_head *a, 148 struct list_head *b) 149 { 150 struct sram_reserve *ra = list_entry(a, struct sram_reserve, list); 151 struct sram_reserve *rb = list_entry(b, struct sram_reserve, list); 152 153 return ra->start - rb->start; 154 } 155 156 static int sram_reserve_regions(struct sram_dev *sram, struct resource *res) 157 { 158 struct device_node *np = sram->dev->of_node, *child; 159 unsigned long size, cur_start, cur_size; 160 struct sram_reserve *rblocks, *block; 161 struct list_head reserve_list; 162 unsigned int nblocks, exports = 0; 163 const char *label; 164 int ret = 0; 165 166 INIT_LIST_HEAD(&reserve_list); 167 168 size = resource_size(res); 169 170 /* 171 * We need an additional block to mark the end of the memory region 172 * after the reserved blocks from the dt are processed. 173 */ 174 nblocks = (np) ? of_get_available_child_count(np) + 1 : 1; 175 rblocks = kcalloc(nblocks, sizeof(*rblocks), GFP_KERNEL); 176 if (!rblocks) 177 return -ENOMEM; 178 179 block = &rblocks[0]; 180 for_each_available_child_of_node(np, child) { 181 struct resource child_res; 182 183 ret = of_address_to_resource(child, 0, &child_res); 184 if (ret < 0) { 185 dev_err(sram->dev, 186 "could not get address for node %pOF\n", 187 child); 188 goto err_chunks; 189 } 190 191 if (child_res.start < res->start || child_res.end > res->end) { 192 dev_err(sram->dev, 193 "reserved block %pOF outside the sram area\n", 194 child); 195 ret = -EINVAL; 196 goto err_chunks; 197 } 198 199 block->start = child_res.start - res->start; 200 block->size = resource_size(&child_res); 201 list_add_tail(&block->list, &reserve_list); 202 203 if (of_find_property(child, "export", NULL)) 204 block->export = true; 205 206 if (of_find_property(child, "pool", NULL)) 207 block->pool = true; 208 209 if (of_find_property(child, "protect-exec", NULL)) 210 block->protect_exec = true; 211 212 if ((block->export || block->pool || block->protect_exec) && 213 block->size) { 214 exports++; 215 216 label = NULL; 217 ret = of_property_read_string(child, "label", &label); 218 if (ret && ret != -EINVAL) { 219 dev_err(sram->dev, 220 "%pOF has invalid label name\n", 221 child); 222 goto err_chunks; 223 } 224 if (!label) 225 label = child->name; 226 227 block->label = devm_kstrdup(sram->dev, 228 label, GFP_KERNEL); 229 if (!block->label) { 230 ret = -ENOMEM; 231 goto err_chunks; 232 } 233 234 dev_dbg(sram->dev, "found %sblock '%s' 0x%x-0x%x\n", 235 block->export ? "exported " : "", block->label, 236 block->start, block->start + block->size); 237 } else { 238 dev_dbg(sram->dev, "found reserved block 0x%x-0x%x\n", 239 block->start, block->start + block->size); 240 } 241 242 block++; 243 } 244 child = NULL; 245 246 /* the last chunk marks the end of the region */ 247 rblocks[nblocks - 1].start = size; 248 rblocks[nblocks - 1].size = 0; 249 list_add_tail(&rblocks[nblocks - 1].list, &reserve_list); 250 251 list_sort(NULL, &reserve_list, sram_reserve_cmp); 252 253 if (exports) { 254 sram->partition = devm_kcalloc(sram->dev, 255 exports, sizeof(*sram->partition), 256 GFP_KERNEL); 257 if (!sram->partition) { 258 ret = -ENOMEM; 259 goto err_chunks; 260 } 261 } 262 263 cur_start = 0; 264 list_for_each_entry(block, &reserve_list, list) { 265 /* can only happen if sections overlap */ 266 if (block->start < cur_start) { 267 dev_err(sram->dev, 268 "block at 0x%x starts after current offset 0x%lx\n", 269 block->start, cur_start); 270 ret = -EINVAL; 271 sram_free_partitions(sram); 272 goto err_chunks; 273 } 274 275 if ((block->export || block->pool || block->protect_exec) && 276 block->size) { 277 ret = sram_add_partition(sram, block, 278 res->start + block->start); 279 if (ret) { 280 sram_free_partitions(sram); 281 goto err_chunks; 282 } 283 } 284 285 /* current start is in a reserved block, so continue after it */ 286 if (block->start == cur_start) { 287 cur_start = block->start + block->size; 288 continue; 289 } 290 291 /* 292 * allocate the space between the current starting 293 * address and the following reserved block, or the 294 * end of the region. 295 */ 296 cur_size = block->start - cur_start; 297 298 dev_dbg(sram->dev, "adding chunk 0x%lx-0x%lx\n", 299 cur_start, cur_start + cur_size); 300 301 ret = gen_pool_add_virt(sram->pool, 302 (unsigned long)sram->virt_base + cur_start, 303 res->start + cur_start, cur_size, -1); 304 if (ret < 0) { 305 sram_free_partitions(sram); 306 goto err_chunks; 307 } 308 309 /* next allocation after this reserved block */ 310 cur_start = block->start + block->size; 311 } 312 313 err_chunks: 314 of_node_put(child); 315 kfree(rblocks); 316 317 return ret; 318 } 319 320 static int atmel_securam_wait(void) 321 { 322 struct regmap *regmap; 323 u32 val; 324 325 regmap = syscon_regmap_lookup_by_compatible("atmel,sama5d2-secumod"); 326 if (IS_ERR(regmap)) 327 return -ENODEV; 328 329 return regmap_read_poll_timeout(regmap, AT91_SECUMOD_RAMRDY, val, 330 val & AT91_SECUMOD_RAMRDY_READY, 331 10000, 500000); 332 } 333 334 static const struct of_device_id sram_dt_ids[] = { 335 { .compatible = "mmio-sram" }, 336 { .compatible = "atmel,sama5d2-securam", .data = atmel_securam_wait }, 337 {} 338 }; 339 340 static int sram_probe(struct platform_device *pdev) 341 { 342 struct sram_dev *sram; 343 struct resource *res; 344 size_t size; 345 int ret; 346 int (*init_func)(void); 347 348 sram = devm_kzalloc(&pdev->dev, sizeof(*sram), GFP_KERNEL); 349 if (!sram) 350 return -ENOMEM; 351 352 sram->dev = &pdev->dev; 353 354 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 355 if (!res) { 356 dev_err(sram->dev, "found no memory resource\n"); 357 return -EINVAL; 358 } 359 360 size = resource_size(res); 361 362 if (!devm_request_mem_region(sram->dev, res->start, size, pdev->name)) { 363 dev_err(sram->dev, "could not request region for resource\n"); 364 return -EBUSY; 365 } 366 367 if (of_property_read_bool(pdev->dev.of_node, "no-memory-wc")) 368 sram->virt_base = devm_ioremap(sram->dev, res->start, size); 369 else 370 sram->virt_base = devm_ioremap_wc(sram->dev, res->start, size); 371 if (!sram->virt_base) 372 return -ENOMEM; 373 374 sram->pool = devm_gen_pool_create(sram->dev, ilog2(SRAM_GRANULARITY), 375 NUMA_NO_NODE, NULL); 376 if (IS_ERR(sram->pool)) 377 return PTR_ERR(sram->pool); 378 379 sram->clk = devm_clk_get(sram->dev, NULL); 380 if (IS_ERR(sram->clk)) 381 sram->clk = NULL; 382 else 383 clk_prepare_enable(sram->clk); 384 385 ret = sram_reserve_regions(sram, res); 386 if (ret) 387 goto err_disable_clk; 388 389 platform_set_drvdata(pdev, sram); 390 391 init_func = of_device_get_match_data(&pdev->dev); 392 if (init_func) { 393 ret = init_func(); 394 if (ret) 395 goto err_free_partitions; 396 } 397 398 dev_dbg(sram->dev, "SRAM pool: %zu KiB @ 0x%p\n", 399 gen_pool_size(sram->pool) / 1024, sram->virt_base); 400 401 return 0; 402 403 err_free_partitions: 404 sram_free_partitions(sram); 405 err_disable_clk: 406 if (sram->clk) 407 clk_disable_unprepare(sram->clk); 408 409 return ret; 410 } 411 412 static int sram_remove(struct platform_device *pdev) 413 { 414 struct sram_dev *sram = platform_get_drvdata(pdev); 415 416 sram_free_partitions(sram); 417 418 if (gen_pool_avail(sram->pool) < gen_pool_size(sram->pool)) 419 dev_err(sram->dev, "removed while SRAM allocated\n"); 420 421 if (sram->clk) 422 clk_disable_unprepare(sram->clk); 423 424 return 0; 425 } 426 427 static struct platform_driver sram_driver = { 428 .driver = { 429 .name = "sram", 430 .of_match_table = sram_dt_ids, 431 }, 432 .probe = sram_probe, 433 .remove = sram_remove, 434 }; 435 436 static int __init sram_init(void) 437 { 438 return platform_driver_register(&sram_driver); 439 } 440 441 postcore_initcall(sram_init); 442