Merge tag 'pci-v5.3-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci
[linux-2.6-microblaze.git] / drivers / misc / sram.c
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);