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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
25static 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
40static 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
55static 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
75static 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
93static 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
129static 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
147static 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
156static 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
313err_chunks:
314 of_node_put(child);
315 kfree(rblocks);
316
317 return ret;
318}
319
320static 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
334static const struct of_device_id sram_dt_ids[] = {
335 { .compatible = "mmio-sram" },
336 { .compatible = "atmel,sama5d2-securam", .data = atmel_securam_wait },
337 {}
338};
339
340static 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
403err_free_partitions:
404 sram_free_partitions(sram);
405err_disable_clk:
406 if (sram->clk)
407 clk_disable_unprepare(sram->clk);
408
409 return ret;
410}
411
412static 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
427static 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
436static int __init sram_init(void)
437{
438 return platform_driver_register(&sram_driver);
439}
440
441postcore_initcall(sram_init);