1 /* 2 * Generic on-chip SRAM allocation driver 3 * 4 * Copyright (C) 2012 Philipp Zabel, Pengutronix 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License 8 * as published by the Free Software Foundation; either version 2 9 * of the License, or (at your option) any later version. 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public License 16 * along with this program; if not, write to the Free Software 17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, 18 * MA 02110-1301, USA. 19 */ 20 21 #include <linux/clk.h> 22 #include <linux/delay.h> 23 #include <linux/genalloc.h> 24 #include <linux/io.h> 25 #include <linux/list_sort.h> 26 #include <linux/of_address.h> 27 #include <linux/of_device.h> 28 #include <linux/platform_device.h> 29 #include <linux/regmap.h> 30 #include <linux/slab.h> 31 #include <linux/mfd/syscon.h> 32 #include <soc/at91/atmel-secumod.h> 33 34 #include "sram.h" 35 36 #define SRAM_GRANULARITY 32 37 38 static ssize_t sram_read(struct file *filp, struct kobject *kobj, 39 struct bin_attribute *attr, 40 char *buf, loff_t pos, size_t count) 41 { 42 struct sram_partition *part; 43 44 part = container_of(attr, struct sram_partition, battr); 45 46 mutex_lock(&part->lock); 47 memcpy_fromio(buf, part->base + pos, count); 48 mutex_unlock(&part->lock); 49 50 return count; 51 } 52 53 static ssize_t sram_write(struct file *filp, struct kobject *kobj, 54 struct bin_attribute *attr, 55 char *buf, loff_t pos, size_t count) 56 { 57 struct sram_partition *part; 58 59 part = container_of(attr, struct sram_partition, battr); 60 61 mutex_lock(&part->lock); 62 memcpy_toio(part->base + pos, buf, count); 63 mutex_unlock(&part->lock); 64 65 return count; 66 } 67 68 static int sram_add_pool(struct sram_dev *sram, struct sram_reserve *block, 69 phys_addr_t start, struct sram_partition *part) 70 { 71 int ret; 72 73 part->pool = devm_gen_pool_create(sram->dev, ilog2(SRAM_GRANULARITY), 74 NUMA_NO_NODE, block->label); 75 if (IS_ERR(part->pool)) 76 return PTR_ERR(part->pool); 77 78 ret = gen_pool_add_virt(part->pool, (unsigned long)part->base, start, 79 block->size, NUMA_NO_NODE); 80 if (ret < 0) { 81 dev_err(sram->dev, "failed to register subpool: %d\n", ret); 82 return ret; 83 } 84 85 return 0; 86 } 87 88 static int sram_add_export(struct sram_dev *sram, struct sram_reserve *block, 89 phys_addr_t start, struct sram_partition *part) 90 { 91 sysfs_bin_attr_init(&part->battr); 92 part->battr.attr.name = devm_kasprintf(sram->dev, GFP_KERNEL, 93 "%llx.sram", 94 (unsigned long long)start); 95 if (!part->battr.attr.name) 96 return -ENOMEM; 97 98 part->battr.attr.mode = S_IRUSR | S_IWUSR; 99 part->battr.read = sram_read; 100 part->battr.write = sram_write; 101 part->battr.size = block->size; 102 103 return device_create_bin_file(sram->dev, &part->battr); 104 } 105 106 static int sram_add_partition(struct sram_dev *sram, struct sram_reserve *block, 107 phys_addr_t start) 108 { 109 int ret; 110 struct sram_partition *part = &sram->partition[sram->partitions]; 111 112 mutex_init(&part->lock); 113 part->base = sram->virt_base + block->start; 114 115 if (block->pool) { 116 ret = sram_add_pool(sram, block, start, part); 117 if (ret) 118 return ret; 119 } 120 if (block->export) { 121 ret = sram_add_export(sram, block, start, part); 122 if (ret) 123 return ret; 124 } 125 if (block->protect_exec) { 126 ret = sram_check_protect_exec(sram, block, part); 127 if (ret) 128 return ret; 129 130 ret = sram_add_pool(sram, block, start, part); 131 if (ret) 132 return ret; 133 134 sram_add_protect_exec(part); 135 } 136 137 sram->partitions++; 138 139 return 0; 140 } 141 142 static void sram_free_partitions(struct sram_dev *sram) 143 { 144 struct sram_partition *part; 145 146 if (!sram->partitions) 147 return; 148 149 part = &sram->partition[sram->partitions - 1]; 150 for (; sram->partitions; sram->partitions--, part--) { 151 if (part->battr.size) 152 device_remove_bin_file(sram->dev, &part->battr); 153 154 if (part->pool && 155 gen_pool_avail(part->pool) < gen_pool_size(part->pool)) 156 dev_err(sram->dev, "removed pool while SRAM allocated\n"); 157 } 158 } 159 160 static int sram_reserve_cmp(void *priv, struct list_head *a, 161 struct list_head *b) 162 { 163 struct sram_reserve *ra = list_entry(a, struct sram_reserve, list); 164 struct sram_reserve *rb = list_entry(b, struct sram_reserve, list); 165 166 return ra->start - rb->start; 167 } 168 169 static int sram_reserve_regions(struct sram_dev *sram, struct resource *res) 170 { 171 struct device_node *np = sram->dev->of_node, *child; 172 unsigned long size, cur_start, cur_size; 173 struct sram_reserve *rblocks, *block; 174 struct list_head reserve_list; 175 unsigned int nblocks, exports = 0; 176 const char *label; 177 int ret = 0; 178 179 INIT_LIST_HEAD(&reserve_list); 180 181 size = resource_size(res); 182 183 /* 184 * We need an additional block to mark the end of the memory region 185 * after the reserved blocks from the dt are processed. 186 */ 187 nblocks = (np) ? of_get_available_child_count(np) + 1 : 1; 188 rblocks = kzalloc((nblocks) * sizeof(*rblocks), GFP_KERNEL); 189 if (!rblocks) 190 return -ENOMEM; 191 192 block = &rblocks[0]; 193 for_each_available_child_of_node(np, child) { 194 struct resource child_res; 195 196 ret = of_address_to_resource(child, 0, &child_res); 197 if (ret < 0) { 198 dev_err(sram->dev, 199 "could not get address for node %s\n", 200 child->full_name); 201 goto err_chunks; 202 } 203 204 if (child_res.start < res->start || child_res.end > res->end) { 205 dev_err(sram->dev, 206 "reserved block %s outside the sram area\n", 207 child->full_name); 208 ret = -EINVAL; 209 goto err_chunks; 210 } 211 212 block->start = child_res.start - res->start; 213 block->size = resource_size(&child_res); 214 list_add_tail(&block->list, &reserve_list); 215 216 if (of_find_property(child, "export", NULL)) 217 block->export = true; 218 219 if (of_find_property(child, "pool", NULL)) 220 block->pool = true; 221 222 if (of_find_property(child, "protect-exec", NULL)) 223 block->protect_exec = true; 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 "%s has invalid label name\n", 234 child->full_name); 235 goto err_chunks; 236 } 237 if (!label) 238 label = child->name; 239 240 block->label = devm_kstrdup(sram->dev, 241 label, GFP_KERNEL); 242 if (!block->label) { 243 ret = -ENOMEM; 244 goto err_chunks; 245 } 246 247 dev_dbg(sram->dev, "found %sblock '%s' 0x%x-0x%x\n", 248 block->export ? "exported " : "", block->label, 249 block->start, block->start + block->size); 250 } else { 251 dev_dbg(sram->dev, "found reserved block 0x%x-0x%x\n", 252 block->start, block->start + block->size); 253 } 254 255 block++; 256 } 257 child = NULL; 258 259 /* the last chunk marks the end of the region */ 260 rblocks[nblocks - 1].start = size; 261 rblocks[nblocks - 1].size = 0; 262 list_add_tail(&rblocks[nblocks - 1].list, &reserve_list); 263 264 list_sort(NULL, &reserve_list, sram_reserve_cmp); 265 266 if (exports) { 267 sram->partition = devm_kzalloc(sram->dev, 268 exports * sizeof(*sram->partition), 269 GFP_KERNEL); 270 if (!sram->partition) { 271 ret = -ENOMEM; 272 goto err_chunks; 273 } 274 } 275 276 cur_start = 0; 277 list_for_each_entry(block, &reserve_list, list) { 278 /* can only happen if sections overlap */ 279 if (block->start < cur_start) { 280 dev_err(sram->dev, 281 "block at 0x%x starts after current offset 0x%lx\n", 282 block->start, cur_start); 283 ret = -EINVAL; 284 sram_free_partitions(sram); 285 goto err_chunks; 286 } 287 288 if ((block->export || block->pool || block->protect_exec) && 289 block->size) { 290 ret = sram_add_partition(sram, block, 291 res->start + block->start); 292 if (ret) { 293 sram_free_partitions(sram); 294 goto err_chunks; 295 } 296 } 297 298 /* current start is in a reserved block, so continue after it */ 299 if (block->start == cur_start) { 300 cur_start = block->start + block->size; 301 continue; 302 } 303 304 /* 305 * allocate the space between the current starting 306 * address and the following reserved block, or the 307 * end of the region. 308 */ 309 cur_size = block->start - cur_start; 310 311 dev_dbg(sram->dev, "adding chunk 0x%lx-0x%lx\n", 312 cur_start, cur_start + cur_size); 313 314 ret = gen_pool_add_virt(sram->pool, 315 (unsigned long)sram->virt_base + cur_start, 316 res->start + cur_start, cur_size, -1); 317 if (ret < 0) { 318 sram_free_partitions(sram); 319 goto err_chunks; 320 } 321 322 /* next allocation after this reserved block */ 323 cur_start = block->start + block->size; 324 } 325 326 err_chunks: 327 if (child) 328 of_node_put(child); 329 330 kfree(rblocks); 331 332 return ret; 333 } 334 335 static int atmel_securam_wait(void) 336 { 337 struct regmap *regmap; 338 u32 val; 339 340 regmap = syscon_regmap_lookup_by_compatible("atmel,sama5d2-secumod"); 341 if (IS_ERR(regmap)) 342 return -ENODEV; 343 344 return regmap_read_poll_timeout(regmap, AT91_SECUMOD_RAMRDY, val, 345 val & AT91_SECUMOD_RAMRDY_READY, 346 10000, 500000); 347 } 348 349 static const struct of_device_id sram_dt_ids[] = { 350 { .compatible = "mmio-sram" }, 351 { .compatible = "atmel,sama5d2-securam", .data = atmel_securam_wait }, 352 {} 353 }; 354 355 static int sram_probe(struct platform_device *pdev) 356 { 357 struct sram_dev *sram; 358 struct resource *res; 359 size_t size; 360 int ret; 361 int (*init_func)(void); 362 363 sram = devm_kzalloc(&pdev->dev, sizeof(*sram), GFP_KERNEL); 364 if (!sram) 365 return -ENOMEM; 366 367 sram->dev = &pdev->dev; 368 369 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 370 if (!res) { 371 dev_err(sram->dev, "found no memory resource\n"); 372 return -EINVAL; 373 } 374 375 size = resource_size(res); 376 377 if (!devm_request_mem_region(sram->dev, res->start, size, pdev->name)) { 378 dev_err(sram->dev, "could not request region for resource\n"); 379 return -EBUSY; 380 } 381 382 if (of_property_read_bool(pdev->dev.of_node, "no-memory-wc")) 383 sram->virt_base = devm_ioremap(sram->dev, res->start, size); 384 else 385 sram->virt_base = devm_ioremap_wc(sram->dev, res->start, size); 386 if (!sram->virt_base) 387 return -ENOMEM; 388 389 sram->pool = devm_gen_pool_create(sram->dev, ilog2(SRAM_GRANULARITY), 390 NUMA_NO_NODE, NULL); 391 if (IS_ERR(sram->pool)) 392 return PTR_ERR(sram->pool); 393 394 ret = sram_reserve_regions(sram, res); 395 if (ret) 396 return ret; 397 398 sram->clk = devm_clk_get(sram->dev, NULL); 399 if (IS_ERR(sram->clk)) 400 sram->clk = NULL; 401 else 402 clk_prepare_enable(sram->clk); 403 404 platform_set_drvdata(pdev, sram); 405 406 init_func = of_device_get_match_data(&pdev->dev); 407 if (init_func) { 408 ret = init_func(); 409 if (ret) 410 return ret; 411 } 412 413 dev_dbg(sram->dev, "SRAM pool: %zu KiB @ 0x%p\n", 414 gen_pool_size(sram->pool) / 1024, sram->virt_base); 415 416 return 0; 417 } 418 419 static int sram_remove(struct platform_device *pdev) 420 { 421 struct sram_dev *sram = platform_get_drvdata(pdev); 422 423 sram_free_partitions(sram); 424 425 if (gen_pool_avail(sram->pool) < gen_pool_size(sram->pool)) 426 dev_err(sram->dev, "removed while SRAM allocated\n"); 427 428 if (sram->clk) 429 clk_disable_unprepare(sram->clk); 430 431 return 0; 432 } 433 434 static struct platform_driver sram_driver = { 435 .driver = { 436 .name = "sram", 437 .of_match_table = sram_dt_ids, 438 }, 439 .probe = sram_probe, 440 .remove = sram_remove, 441 }; 442 443 static int __init sram_init(void) 444 { 445 return platform_driver_register(&sram_driver); 446 } 447 448 postcore_initcall(sram_init); 449