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.h>
14#include <linux/of_address.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(lock: &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(lock: &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(dev: sram->dev, ilog2(SRAM_GRANULARITY),
61 NUMA_NO_NODE, name: block->label);
62 if (IS_ERR(ptr: part->pool))
63 return PTR_ERR(ptr: part->pool);
64
65 ret = gen_pool_add_virt(pool: part->pool, addr: (unsigned long)part->base, phys: start,
66 size: 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(dev: sram->dev, GFP_KERNEL,
80 fmt: "%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(dev: sram->dev, attr: &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
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(dev: sram->dev, res: &block->res);
106 else
107 virt_base = devm_ioremap_resource_wc(dev: sram->dev, res: &block->res);
108
109 if (IS_ERR(ptr: virt_base)) {
110 dev_err(sram->dev, "could not map SRAM at %pr\n", &block->res);
111 return PTR_ERR(ptr: 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
146static 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(dev: sram->dev, attr: &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
164static 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
173static 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(list: &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(n: nblocks, size: 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(dev: child, index: 0, r: &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(res: &child_res);
218 block->res = child_res;
219 list_add_tail(new: &block->list, head: &reserve_list);
220
221 block->export = of_property_read_bool(np: child, propname: "export");
222 block->pool = of_property_read_bool(np: child, propname: "pool");
223 block->protect_exec = of_property_read_bool(np: child, propname: "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(np: child, propname: "label", out_string: &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(dev: sram->dev, GFP_KERNEL,
239 fmt: "%s", of_node_full_name(np: child));
240 else
241 block->label = devm_kstrdup(dev: sram->dev,
242 s: 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(new: &rblocks[nblocks - 1].list, head: &reserve_list);
264
265 list_sort(NULL, head: &reserve_list, cmp: sram_reserve_cmp);
266
267 if (exports) {
268 sram->partition = devm_kcalloc(dev: sram->dev,
269 n: exports, size: 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 start: 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(pool: sram->pool,
317 addr: (unsigned long)sram->virt_base + cur_start,
318 phys: res->start + cur_start, size: cur_size, nid: -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
329err_chunks:
330 of_node_put(node: child);
331 kfree(objp: rblocks);
332
333 return ret;
334}
335
336static int atmel_securam_wait(void)
337{
338 struct regmap *regmap;
339 u32 val;
340
341 regmap = syscon_regmap_lookup_by_compatible(s: "atmel,sama5d2-secumod");
342 if (IS_ERR(ptr: 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
350static 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 */
361static const struct sram_config tegra_sysram_config = {
362 .map_only_reserved = true,
363};
364
365static 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
374static 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(dev: &pdev->dev);
383
384 sram = devm_kzalloc(dev: &pdev->dev, size: 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(np: pdev->dev.of_node, propname: "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(dev: &pdev->dev, res);
396 else
397 sram->virt_base = devm_ioremap_resource_wc(dev: &pdev->dev, res);
398 if (IS_ERR(ptr: sram->virt_base)) {
399 dev_err(&pdev->dev, "could not map SRAM registers\n");
400 return PTR_ERR(ptr: sram->virt_base);
401 }
402
403 sram->pool = devm_gen_pool_create(dev: sram->dev, ilog2(SRAM_GRANULARITY),
404 NUMA_NO_NODE, NULL);
405 if (IS_ERR(ptr: sram->pool))
406 return PTR_ERR(ptr: sram->pool);
407 }
408
409 clk = devm_clk_get_optional_enabled(dev: sram->dev, NULL);
410 if (IS_ERR(ptr: clk))
411 return PTR_ERR(ptr: clk);
412
413 ret = sram_reserve_regions(sram,
414 res: platform_get_resource(pdev, IORESOURCE_MEM, 0));
415 if (ret)
416 return ret;
417
418 platform_set_drvdata(pdev, data: 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
432err_free_partitions:
433 sram_free_partitions(sram);
434
435 return ret;
436}
437
438static 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
450static 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
459static int __init sram_init(void)
460{
461 return platform_driver_register(&sram_driver);
462}
463
464postcore_initcall(sram_init);
465

source code of linux/drivers/misc/sram.c