2 * Generic on-chip SRAM allocation driver
4 * Copyright (C) 2012 Philipp Zabel, Pengutronix
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.
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,
21 #include <linux/clk.h>
22 #include <linux/delay.h>
23 #include <linux/genalloc.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>
36 #define SRAM_GRANULARITY 32
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)
42 struct sram_partition *part;
44 part = container_of(attr, struct sram_partition, battr);
46 mutex_lock(&part->lock);
47 memcpy_fromio(buf, part->base + pos, count);
48 mutex_unlock(&part->lock);
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)
57 struct sram_partition *part;
59 part = container_of(attr, struct sram_partition, battr);
61 mutex_lock(&part->lock);
62 memcpy_toio(part->base + pos, buf, count);
63 mutex_unlock(&part->lock);
68 static int sram_add_pool(struct sram_dev *sram, struct sram_reserve *block,
69 phys_addr_t start, struct sram_partition *part)
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);
78 ret = gen_pool_add_virt(part->pool, (unsigned long)part->base, start,
79 block->size, NUMA_NO_NODE);
81 dev_err(sram->dev, "failed to register subpool: %d\n", ret);
88 static int sram_add_export(struct sram_dev *sram, struct sram_reserve *block,
89 phys_addr_t start, struct sram_partition *part)
91 sysfs_bin_attr_init(&part->battr);
92 part->battr.attr.name = devm_kasprintf(sram->dev, GFP_KERNEL,
94 (unsigned long long)start);
95 if (!part->battr.attr.name)
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;
103 return device_create_bin_file(sram->dev, &part->battr);
106 static int sram_add_partition(struct sram_dev *sram, struct sram_reserve *block,
110 struct sram_partition *part = &sram->partition[sram->partitions];
112 mutex_init(&part->lock);
113 part->base = sram->virt_base + block->start;
116 ret = sram_add_pool(sram, block, start, part);
121 ret = sram_add_export(sram, block, start, part);
125 if (block->protect_exec) {
126 ret = sram_check_protect_exec(sram, block, part);
130 ret = sram_add_pool(sram, block, start, part);
134 sram_add_protect_exec(part);
142 static void sram_free_partitions(struct sram_dev *sram)
144 struct sram_partition *part;
146 if (!sram->partitions)
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);
155 gen_pool_avail(part->pool) < gen_pool_size(part->pool))
156 dev_err(sram->dev, "removed pool while SRAM allocated\n");
160 static int sram_reserve_cmp(void *priv, struct list_head *a,
163 struct sram_reserve *ra = list_entry(a, struct sram_reserve, list);
164 struct sram_reserve *rb = list_entry(b, struct sram_reserve, list);
166 return ra->start - rb->start;
169 static int sram_reserve_regions(struct sram_dev *sram, struct resource *res)
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;
179 INIT_LIST_HEAD(&reserve_list);
181 size = resource_size(res);
184 * We need an additional block to mark the end of the memory region
185 * after the reserved blocks from the dt are processed.
187 nblocks = (np) ? of_get_available_child_count(np) + 1 : 1;
188 rblocks = kcalloc(nblocks, sizeof(*rblocks), GFP_KERNEL);
193 for_each_available_child_of_node(np, child) {
194 struct resource child_res;
196 ret = of_address_to_resource(child, 0, &child_res);
199 "could not get address for node %pOF\n",
204 if (child_res.start < res->start || child_res.end > res->end) {
206 "reserved block %pOF outside the sram area\n",
212 block->start = child_res.start - res->start;
213 block->size = resource_size(&child_res);
214 list_add_tail(&block->list, &reserve_list);
216 if (of_find_property(child, "export", NULL))
217 block->export = true;
219 if (of_find_property(child, "pool", NULL))
222 if (of_find_property(child, "protect-exec", NULL))
223 block->protect_exec = true;
225 if ((block->export || block->pool || block->protect_exec) &&
230 ret = of_property_read_string(child, "label", &label);
231 if (ret && ret != -EINVAL) {
233 "%pOF has invalid label name\n",
240 block->label = devm_kstrdup(sram->dev,
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);
251 dev_dbg(sram->dev, "found reserved block 0x%x-0x%x\n",
252 block->start, block->start + block->size);
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);
264 list_sort(NULL, &reserve_list, sram_reserve_cmp);
267 sram->partition = devm_kcalloc(sram->dev,
268 exports, sizeof(*sram->partition),
270 if (!sram->partition) {
277 list_for_each_entry(block, &reserve_list, list) {
278 /* can only happen if sections overlap */
279 if (block->start < cur_start) {
281 "block at 0x%x starts after current offset 0x%lx\n",
282 block->start, cur_start);
284 sram_free_partitions(sram);
288 if ((block->export || block->pool || block->protect_exec) &&
290 ret = sram_add_partition(sram, block,
291 res->start + block->start);
293 sram_free_partitions(sram);
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;
305 * allocate the space between the current starting
306 * address and the following reserved block, or the
309 cur_size = block->start - cur_start;
311 dev_dbg(sram->dev, "adding chunk 0x%lx-0x%lx\n",
312 cur_start, cur_start + cur_size);
314 ret = gen_pool_add_virt(sram->pool,
315 (unsigned long)sram->virt_base + cur_start,
316 res->start + cur_start, cur_size, -1);
318 sram_free_partitions(sram);
322 /* next allocation after this reserved block */
323 cur_start = block->start + block->size;
333 static int atmel_securam_wait(void)
335 struct regmap *regmap;
338 regmap = syscon_regmap_lookup_by_compatible("atmel,sama5d2-secumod");
342 return regmap_read_poll_timeout(regmap, AT91_SECUMOD_RAMRDY, val,
343 val & AT91_SECUMOD_RAMRDY_READY,
347 static const struct of_device_id sram_dt_ids[] = {
348 { .compatible = "mmio-sram" },
349 { .compatible = "atmel,sama5d2-securam", .data = atmel_securam_wait },
353 static int sram_probe(struct platform_device *pdev)
355 struct sram_dev *sram;
356 struct resource *res;
359 int (*init_func)(void);
361 sram = devm_kzalloc(&pdev->dev, sizeof(*sram), GFP_KERNEL);
365 sram->dev = &pdev->dev;
367 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
369 dev_err(sram->dev, "found no memory resource\n");
373 size = resource_size(res);
375 if (!devm_request_mem_region(sram->dev, res->start, size, pdev->name)) {
376 dev_err(sram->dev, "could not request region for resource\n");
380 if (of_property_read_bool(pdev->dev.of_node, "no-memory-wc"))
381 sram->virt_base = devm_ioremap(sram->dev, res->start, size);
383 sram->virt_base = devm_ioremap_wc(sram->dev, res->start, size);
384 if (!sram->virt_base)
387 sram->pool = devm_gen_pool_create(sram->dev, ilog2(SRAM_GRANULARITY),
389 if (IS_ERR(sram->pool))
390 return PTR_ERR(sram->pool);
392 sram->clk = devm_clk_get(sram->dev, NULL);
393 if (IS_ERR(sram->clk))
396 clk_prepare_enable(sram->clk);
398 ret = sram_reserve_regions(sram, res);
400 goto err_disable_clk;
402 platform_set_drvdata(pdev, sram);
404 init_func = of_device_get_match_data(&pdev->dev);
408 goto err_free_partitions;
411 dev_dbg(sram->dev, "SRAM pool: %zu KiB @ 0x%p\n",
412 gen_pool_size(sram->pool) / 1024, sram->virt_base);
417 sram_free_partitions(sram);
420 clk_disable_unprepare(sram->clk);
425 static int sram_remove(struct platform_device *pdev)
427 struct sram_dev *sram = platform_get_drvdata(pdev);
429 sram_free_partitions(sram);
431 if (gen_pool_avail(sram->pool) < gen_pool_size(sram->pool))
432 dev_err(sram->dev, "removed while SRAM allocated\n");
435 clk_disable_unprepare(sram->clk);
440 static struct platform_driver sram_driver = {
443 .of_match_table = sram_dt_ids,
446 .remove = sram_remove,
449 static int __init sram_init(void)
451 return platform_driver_register(&sram_driver);
454 postcore_initcall(sram_init);