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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/genalloc.h>
23#include <linux/io.h>
24#include <linux/list_sort.h>
25#include <linux/of_address.h>
26#include <linux/platform_device.h>
27#include <linux/slab.h>
28
29#define SRAM_GRANULARITY 32
30
31struct sram_partition {
32 void __iomem *base;
33
34 struct gen_pool *pool;
35 struct bin_attribute battr;
36 struct mutex lock;
37};
38
39struct sram_dev {
40 struct device *dev;
41 void __iomem *virt_base;
42
43 struct gen_pool *pool;
44 struct clk *clk;
45
46 struct sram_partition *partition;
47 u32 partitions;
48};
49
50struct sram_reserve {
51 struct list_head list;
52 u32 start;
53 u32 size;
54 bool export;
55 bool pool;
56 const char *label;
57};
58
59static ssize_t sram_read(struct file *filp, struct kobject *kobj,
60 struct bin_attribute *attr,
61 char *buf, loff_t pos, size_t count)
62{
63 struct sram_partition *part;
64
65 part = container_of(attr, struct sram_partition, battr);
66
67 mutex_lock(&part->lock);
68 memcpy_fromio(buf, part->base + pos, count);
69 mutex_unlock(&part->lock);
70
71 return count;
72}
73
74static ssize_t sram_write(struct file *filp, struct kobject *kobj,
75 struct bin_attribute *attr,
76 char *buf, loff_t pos, size_t count)
77{
78 struct sram_partition *part;
79
80 part = container_of(attr, struct sram_partition, battr);
81
82 mutex_lock(&part->lock);
83 memcpy_toio(part->base + pos, buf, count);
84 mutex_unlock(&part->lock);
85
86 return count;
87}
88
89static int sram_add_pool(struct sram_dev *sram, struct sram_reserve *block,
90 phys_addr_t start, struct sram_partition *part)
91{
92 int ret;
93
94 part->pool = devm_gen_pool_create(sram->dev, ilog2(SRAM_GRANULARITY),
95 NUMA_NO_NODE, block->label);
96 if (IS_ERR(part->pool))
97 return PTR_ERR(part->pool);
98
99 ret = gen_pool_add_virt(part->pool, (unsigned long)part->base, start,
100 block->size, NUMA_NO_NODE);
101 if (ret < 0) {
102 dev_err(sram->dev, "failed to register subpool: %d\n", ret);
103 return ret;
104 }
105
106 return 0;
107}
108
109static int sram_add_export(struct sram_dev *sram, struct sram_reserve *block,
110 phys_addr_t start, struct sram_partition *part)
111{
112 sysfs_bin_attr_init(&part->battr);
113 part->battr.attr.name = devm_kasprintf(sram->dev, GFP_KERNEL,
114 "%llx.sram",
115 (unsigned long long)start);
116 if (!part->battr.attr.name)
117 return -ENOMEM;
118
119 part->battr.attr.mode = S_IRUSR | S_IWUSR;
120 part->battr.read = sram_read;
121 part->battr.write = sram_write;
122 part->battr.size = block->size;
123
124 return device_create_bin_file(sram->dev, &part->battr);
125}
126
127static int sram_add_partition(struct sram_dev *sram, struct sram_reserve *block,
128 phys_addr_t start)
129{
130 int ret;
131 struct sram_partition *part = &sram->partition[sram->partitions];
132
133 mutex_init(&part->lock);
134 part->base = sram->virt_base + block->start;
135
136 if (block->pool) {
137 ret = sram_add_pool(sram, block, start, part);
138 if (ret)
139 return ret;
140 }
141 if (block->export) {
142 ret = sram_add_export(sram, block, start, part);
143 if (ret)
144 return ret;
145 }
146 sram->partitions++;
147
148 return 0;
149}
150
151static void sram_free_partitions(struct sram_dev *sram)
152{
153 struct sram_partition *part;
154
155 if (!sram->partitions)
156 return;
157
158 part = &sram->partition[sram->partitions - 1];
159 for (; sram->partitions; sram->partitions--, part--) {
160 if (part->battr.size)
161 device_remove_bin_file(sram->dev, &part->battr);
162
163 if (part->pool &&
164 gen_pool_avail(part->pool) < gen_pool_size(part->pool))
165 dev_err(sram->dev, "removed pool while SRAM allocated\n");
166 }
167}
168
169static int sram_reserve_cmp(void *priv, struct list_head *a,
170 struct list_head *b)
171{
172 struct sram_reserve *ra = list_entry(a, struct sram_reserve, list);
173 struct sram_reserve *rb = list_entry(b, struct sram_reserve, list);
174
175 return ra->start - rb->start;
176}
177
178static int sram_reserve_regions(struct sram_dev *sram, struct resource *res)
179{
180 struct device_node *np = sram->dev->of_node, *child;
181 unsigned long size, cur_start, cur_size;
182 struct sram_reserve *rblocks, *block;
183 struct list_head reserve_list;
184 unsigned int nblocks, exports = 0;
185 const char *label;
186 int ret = 0;
187
188 INIT_LIST_HEAD(&reserve_list);
189
190 size = resource_size(res);
191
192 /*
193 * We need an additional block to mark the end of the memory region
194 * after the reserved blocks from the dt are processed.
195 */
196 nblocks = (np) ? of_get_available_child_count(np) + 1 : 1;
197 rblocks = kzalloc((nblocks) * sizeof(*rblocks), GFP_KERNEL);
198 if (!rblocks)
199 return -ENOMEM;
200
201 block = &rblocks[0];
202 for_each_available_child_of_node(np, child) {
203 struct resource child_res;
204
205 ret = of_address_to_resource(child, 0, &child_res);
206 if (ret < 0) {
207 dev_err(sram->dev,
208 "could not get address for node %s\n",
209 child->full_name);
210 goto err_chunks;
211 }
212
213 if (child_res.start < res->start || child_res.end > res->end) {
214 dev_err(sram->dev,
215 "reserved block %s outside the sram area\n",
216 child->full_name);
217 ret = -EINVAL;
218 goto err_chunks;
219 }
220
221 block->start = child_res.start - res->start;
222 block->size = resource_size(&child_res);
223 list_add_tail(&block->list, &reserve_list);
224
225 if (of_find_property(child, "export", NULL))
226 block->export = true;
227
228 if (of_find_property(child, "pool", NULL))
229 block->pool = true;
230
231 if ((block->export || block->pool) && block->size) {
232 exports++;
233
234 label = NULL;
235 ret = of_property_read_string(child, "label", &label);
236 if (ret && ret != -EINVAL) {
237 dev_err(sram->dev,
238 "%s has invalid label name\n",
239 child->full_name);
240 goto err_chunks;
241 }
242 if (!label)
243 label = child->name;
244
245 block->label = devm_kstrdup(sram->dev,
246 label, GFP_KERNEL);
247 if (!block->label)
248 goto err_chunks;
249
250 dev_dbg(sram->dev, "found %sblock '%s' 0x%x-0x%x\n",
251 block->export ? "exported " : "", block->label,
252 block->start, block->start + block->size);
253 } else {
254 dev_dbg(sram->dev, "found reserved block 0x%x-0x%x\n",
255 block->start, block->start + block->size);
256 }
257
258 block++;
259 }
260 child = NULL;
261
262 /* the last chunk marks the end of the region */
263 rblocks[nblocks - 1].start = size;
264 rblocks[nblocks - 1].size = 0;
265 list_add_tail(&rblocks[nblocks - 1].list, &reserve_list);
266
267 list_sort(NULL, &reserve_list, sram_reserve_cmp);
268
269 if (exports) {
270 sram->partition = devm_kzalloc(sram->dev,
271 exports * sizeof(*sram->partition),
272 GFP_KERNEL);
273 if (!sram->partition) {
274 ret = -ENOMEM;
275 goto err_chunks;
276 }
277 }
278
279 cur_start = 0;
280 list_for_each_entry(block, &reserve_list, list) {
281 /* can only happen if sections overlap */
282 if (block->start < cur_start) {
283 dev_err(sram->dev,
284 "block at 0x%x starts after current offset 0x%lx\n",
285 block->start, cur_start);
286 ret = -EINVAL;
287 sram_free_partitions(sram);
288 goto err_chunks;
289 }
290
291 if ((block->export || block->pool) && block->size) {
292 ret = sram_add_partition(sram, block,
293 res->start + block->start);
294 if (ret) {
295 sram_free_partitions(sram);
296 goto err_chunks;
297 }
298 }
299
300 /* current start is in a reserved block, so continue after it */
301 if (block->start == cur_start) {
302 cur_start = block->start + block->size;
303 continue;
304 }
305
306 /*
307 * allocate the space between the current starting
308 * address and the following reserved block, or the
309 * end of the region.
310 */
311 cur_size = block->start - cur_start;
312
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(sram->pool,
317 (unsigned long)sram->virt_base + cur_start,
318 res->start + cur_start, cur_size, -1);
319 if (ret < 0) {
320 sram_free_partitions(sram);
321 goto err_chunks;
322 }
323
324 /* next allocation after this reserved block */
325 cur_start = block->start + block->size;
326 }
327
328 err_chunks:
329 if (child)
330 of_node_put(child);
331
332 kfree(rblocks);
333
334 return ret;
335}
336
337static int sram_probe(struct platform_device *pdev)
338{
339 struct sram_dev *sram;
340 struct resource *res;
341 size_t size;
342 int ret;
343
344 sram = devm_kzalloc(&pdev->dev, sizeof(*sram), GFP_KERNEL);
345 if (!sram)
346 return -ENOMEM;
347
348 sram->dev = &pdev->dev;
349
350 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
351 if (!res) {
352 dev_err(sram->dev, "found no memory resource\n");
353 return -EINVAL;
354 }
355
356 size = resource_size(res);
357
358 if (!devm_request_mem_region(sram->dev, res->start, size, pdev->name)) {
359 dev_err(sram->dev, "could not request region for resource\n");
360 return -EBUSY;
361 }
362
363 if (of_property_read_bool(pdev->dev.of_node, "no-memory-wc"))
364 sram->virt_base = devm_ioremap(sram->dev, res->start, size);
365 else
366 sram->virt_base = devm_ioremap_wc(sram->dev, res->start, size);
367 if (IS_ERR(sram->virt_base))
368 return PTR_ERR(sram->virt_base);
369
370 sram->pool = devm_gen_pool_create(sram->dev, ilog2(SRAM_GRANULARITY),
371 NUMA_NO_NODE, NULL);
372 if (IS_ERR(sram->pool))
373 return PTR_ERR(sram->pool);
374
375 ret = sram_reserve_regions(sram, res);
376 if (ret)
377 return ret;
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 platform_set_drvdata(pdev, sram);
386
387 dev_dbg(sram->dev, "SRAM pool: %zu KiB @ 0x%p\n",
388 gen_pool_size(sram->pool) / 1024, sram->virt_base);
389
390 return 0;
391}
392
393static int sram_remove(struct platform_device *pdev)
394{
395 struct sram_dev *sram = platform_get_drvdata(pdev);
396
397 sram_free_partitions(sram);
398
399 if (gen_pool_avail(sram->pool) < gen_pool_size(sram->pool))
400 dev_err(sram->dev, "removed while SRAM allocated\n");
401
402 if (sram->clk)
403 clk_disable_unprepare(sram->clk);
404
405 return 0;
406}
407
408#ifdef CONFIG_OF
409static const struct of_device_id sram_dt_ids[] = {
410 { .compatible = "mmio-sram" },
411 {}
412};
413#endif
414
415static struct platform_driver sram_driver = {
416 .driver = {
417 .name = "sram",
418 .of_match_table = of_match_ptr(sram_dt_ids),
419 },
420 .probe = sram_probe,
421 .remove = sram_remove,
422};
423
424static int __init sram_init(void)
425{
426 return platform_driver_register(&sram_driver);
427}
428
429postcore_initcall(sram_init);
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/kernel.h>
22#include <linux/init.h>
23#include <linux/clk.h>
24#include <linux/err.h>
25#include <linux/io.h>
26#include <linux/of.h>
27#include <linux/of_address.h>
28#include <linux/list.h>
29#include <linux/list_sort.h>
30#include <linux/platform_device.h>
31#include <linux/slab.h>
32#include <linux/spinlock.h>
33#include <linux/genalloc.h>
34
35#define SRAM_GRANULARITY 32
36
37struct sram_dev {
38 struct gen_pool *pool;
39 struct clk *clk;
40};
41
42struct sram_reserve {
43 struct list_head list;
44 u32 start;
45 u32 size;
46};
47
48static int sram_reserve_cmp(void *priv, struct list_head *a,
49 struct list_head *b)
50{
51 struct sram_reserve *ra = list_entry(a, struct sram_reserve, list);
52 struct sram_reserve *rb = list_entry(b, struct sram_reserve, list);
53
54 return ra->start - rb->start;
55}
56
57static int sram_probe(struct platform_device *pdev)
58{
59 void __iomem *virt_base;
60 struct sram_dev *sram;
61 struct resource *res;
62 struct device_node *np = pdev->dev.of_node, *child;
63 unsigned long size, cur_start, cur_size;
64 struct sram_reserve *rblocks, *block;
65 struct list_head reserve_list;
66 unsigned int nblocks;
67 int ret;
68
69 INIT_LIST_HEAD(&reserve_list);
70
71 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
72 virt_base = devm_ioremap_resource(&pdev->dev, res);
73 if (IS_ERR(virt_base))
74 return PTR_ERR(virt_base);
75
76 size = resource_size(res);
77
78 sram = devm_kzalloc(&pdev->dev, sizeof(*sram), GFP_KERNEL);
79 if (!sram)
80 return -ENOMEM;
81
82 sram->clk = devm_clk_get(&pdev->dev, NULL);
83 if (IS_ERR(sram->clk))
84 sram->clk = NULL;
85 else
86 clk_prepare_enable(sram->clk);
87
88 sram->pool = devm_gen_pool_create(&pdev->dev, ilog2(SRAM_GRANULARITY), -1);
89 if (!sram->pool)
90 return -ENOMEM;
91
92 /*
93 * We need an additional block to mark the end of the memory region
94 * after the reserved blocks from the dt are processed.
95 */
96 nblocks = (np) ? of_get_available_child_count(np) + 1 : 1;
97 rblocks = kmalloc((nblocks) * sizeof(*rblocks), GFP_KERNEL);
98 if (!rblocks) {
99 ret = -ENOMEM;
100 goto err_alloc;
101 }
102
103 block = &rblocks[0];
104 for_each_available_child_of_node(np, child) {
105 struct resource child_res;
106
107 ret = of_address_to_resource(child, 0, &child_res);
108 if (ret < 0) {
109 dev_err(&pdev->dev,
110 "could not get address for node %s\n",
111 child->full_name);
112 goto err_chunks;
113 }
114
115 if (child_res.start < res->start || child_res.end > res->end) {
116 dev_err(&pdev->dev,
117 "reserved block %s outside the sram area\n",
118 child->full_name);
119 ret = -EINVAL;
120 goto err_chunks;
121 }
122
123 block->start = child_res.start - res->start;
124 block->size = resource_size(&child_res);
125 list_add_tail(&block->list, &reserve_list);
126
127 dev_dbg(&pdev->dev, "found reserved block 0x%x-0x%x\n",
128 block->start,
129 block->start + block->size);
130
131 block++;
132 }
133
134 /* the last chunk marks the end of the region */
135 rblocks[nblocks - 1].start = size;
136 rblocks[nblocks - 1].size = 0;
137 list_add_tail(&rblocks[nblocks - 1].list, &reserve_list);
138
139 list_sort(NULL, &reserve_list, sram_reserve_cmp);
140
141 cur_start = 0;
142
143 list_for_each_entry(block, &reserve_list, list) {
144 /* can only happen if sections overlap */
145 if (block->start < cur_start) {
146 dev_err(&pdev->dev,
147 "block at 0x%x starts after current offset 0x%lx\n",
148 block->start, cur_start);
149 ret = -EINVAL;
150 goto err_chunks;
151 }
152
153 /* current start is in a reserved block, so continue after it */
154 if (block->start == cur_start) {
155 cur_start = block->start + block->size;
156 continue;
157 }
158
159 /*
160 * allocate the space between the current starting
161 * address and the following reserved block, or the
162 * end of the region.
163 */
164 cur_size = block->start - cur_start;
165
166 dev_dbg(&pdev->dev, "adding chunk 0x%lx-0x%lx\n",
167 cur_start, cur_start + cur_size);
168 ret = gen_pool_add_virt(sram->pool,
169 (unsigned long)virt_base + cur_start,
170 res->start + cur_start, cur_size, -1);
171 if (ret < 0)
172 goto err_chunks;
173
174 /* next allocation after this reserved block */
175 cur_start = block->start + block->size;
176 }
177
178 kfree(rblocks);
179
180 platform_set_drvdata(pdev, sram);
181
182 dev_dbg(&pdev->dev, "SRAM pool: %ld KiB @ 0x%p\n", size / 1024, virt_base);
183
184 return 0;
185
186err_chunks:
187 kfree(rblocks);
188err_alloc:
189 if (sram->clk)
190 clk_disable_unprepare(sram->clk);
191 return ret;
192}
193
194static int sram_remove(struct platform_device *pdev)
195{
196 struct sram_dev *sram = platform_get_drvdata(pdev);
197
198 if (gen_pool_avail(sram->pool) < gen_pool_size(sram->pool))
199 dev_dbg(&pdev->dev, "removed while SRAM allocated\n");
200
201 if (sram->clk)
202 clk_disable_unprepare(sram->clk);
203
204 return 0;
205}
206
207#ifdef CONFIG_OF
208static struct of_device_id sram_dt_ids[] = {
209 { .compatible = "mmio-sram" },
210 {}
211};
212#endif
213
214static struct platform_driver sram_driver = {
215 .driver = {
216 .name = "sram",
217 .of_match_table = of_match_ptr(sram_dt_ids),
218 },
219 .probe = sram_probe,
220 .remove = sram_remove,
221};
222
223static int __init sram_init(void)
224{
225 return platform_driver_register(&sram_driver);
226}
227
228postcore_initcall(sram_init);