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dbdf04c4 MS |
1 | /* |
2 | * (C) Copyright IBM Deutschland Entwicklung GmbH 2006 | |
3 | * | |
4 | * Author: Maxim Shchetynin <maxim@de.ibm.com> | |
5 | * | |
6 | * Axon DDR2 device driver. | |
7 | * It registers one block device per Axon's DDR2 memory bank found on a system. | |
8 | * Block devices are called axonram?, their major and minor numbers are | |
9 | * available in /proc/devices, /proc/partitions or in /sys/block/axonram?/dev. | |
10 | * | |
11 | * This program is free software; you can redistribute it and/or modify | |
12 | * it under the terms of the GNU General Public License as published by | |
13 | * the Free Software Foundation; either version 2, or (at your option) | |
14 | * any later version. | |
15 | * | |
16 | * This program is distributed in the hope that it will be useful, | |
17 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
18 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
19 | * GNU General Public License for more details. | |
20 | * | |
21 | * You should have received a copy of the GNU General Public License | |
22 | * along with this program; if not, write to the Free Software | |
23 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
24 | */ | |
25 | ||
26 | #include <linux/bio.h> | |
27 | #include <linux/blkdev.h> | |
28 | #include <linux/buffer_head.h> | |
29 | #include <linux/device.h> | |
30 | #include <linux/errno.h> | |
31 | #include <linux/fs.h> | |
32 | #include <linux/genhd.h> | |
33 | #include <linux/interrupt.h> | |
34 | #include <linux/io.h> | |
35 | #include <linux/ioport.h> | |
36 | #include <linux/irq.h> | |
37 | #include <linux/irqreturn.h> | |
38 | #include <linux/kernel.h> | |
39 | #include <linux/mm.h> | |
40 | #include <linux/mod_devicetable.h> | |
41 | #include <linux/module.h> | |
42 | #include <linux/slab.h> | |
43 | #include <linux/string.h> | |
44 | #include <linux/types.h> | |
45 | #include <asm/of_device.h> | |
46 | #include <asm/of_platform.h> | |
47 | #include <asm/page.h> | |
48 | #include <asm/prom.h> | |
49 | ||
50 | #define AXON_RAM_MODULE_NAME "axonram" | |
51 | #define AXON_RAM_DEVICE_NAME "axonram" | |
52 | #define AXON_RAM_MINORS_PER_DISK 16 | |
53 | #define AXON_RAM_BLOCK_SHIFT PAGE_SHIFT | |
54 | #define AXON_RAM_BLOCK_SIZE 1 << AXON_RAM_BLOCK_SHIFT | |
55 | #define AXON_RAM_SECTOR_SHIFT 9 | |
56 | #define AXON_RAM_SECTOR_SIZE 1 << AXON_RAM_SECTOR_SHIFT | |
57 | #define AXON_RAM_IRQ_FLAGS IRQF_SHARED | IRQF_TRIGGER_RISING | |
58 | ||
59 | struct axon_ram_bank { | |
60 | struct of_device *device; | |
61 | struct gendisk *disk; | |
fedcd2c5 | 62 | unsigned int irq_id; |
dbdf04c4 MS |
63 | unsigned long ph_addr; |
64 | unsigned long io_addr; | |
65 | unsigned long size; | |
66 | unsigned long ecc_counter; | |
67 | }; | |
68 | ||
69 | static ssize_t | |
70 | axon_ram_sysfs_ecc(struct device *dev, struct device_attribute *attr, char *buf) | |
71 | { | |
72 | struct of_device *device = to_of_device(dev); | |
73 | struct axon_ram_bank *bank = device->dev.platform_data; | |
74 | ||
75 | BUG_ON(!bank); | |
76 | ||
77 | return sprintf(buf, "%ld\n", bank->ecc_counter); | |
78 | } | |
79 | ||
80 | static DEVICE_ATTR(ecc, S_IRUGO, axon_ram_sysfs_ecc, NULL); | |
81 | ||
82 | /** | |
83 | * axon_ram_irq_handler - interrupt handler for Axon RAM ECC | |
84 | * @irq: interrupt ID | |
85 | * @dev: pointer to of_device | |
86 | */ | |
87 | static irqreturn_t | |
88 | axon_ram_irq_handler(int irq, void *dev) | |
89 | { | |
90 | struct of_device *device = dev; | |
91 | struct axon_ram_bank *bank = device->dev.platform_data; | |
92 | ||
93 | BUG_ON(!bank); | |
94 | ||
fedcd2c5 MS |
95 | dev_err(&device->dev, "Correctable memory error occured\n"); |
96 | bank->ecc_counter++; | |
97 | return IRQ_HANDLED; | |
dbdf04c4 MS |
98 | } |
99 | ||
100 | /** | |
101 | * axon_ram_make_request - make_request() method for block device | |
102 | * @queue, @bio: see blk_queue_make_request() | |
103 | */ | |
104 | static int | |
105 | axon_ram_make_request(struct request_queue *queue, struct bio *bio) | |
106 | { | |
107 | struct axon_ram_bank *bank = bio->bi_bdev->bd_disk->private_data; | |
108 | unsigned long phys_mem, phys_end; | |
109 | void *user_mem; | |
110 | struct bio_vec *vec; | |
111 | unsigned int transfered; | |
112 | unsigned short idx; | |
113 | int rc = 0; | |
114 | ||
115 | phys_mem = bank->io_addr + (bio->bi_sector << AXON_RAM_SECTOR_SHIFT); | |
116 | phys_end = bank->io_addr + bank->size; | |
117 | transfered = 0; | |
118 | bio_for_each_segment(vec, bio, idx) { | |
119 | if (unlikely(phys_mem + vec->bv_len > phys_end)) { | |
120 | bio_io_error(bio, bio->bi_size); | |
121 | rc = -ERANGE; | |
122 | break; | |
123 | } | |
124 | ||
125 | user_mem = page_address(vec->bv_page) + vec->bv_offset; | |
126 | if (bio_data_dir(bio) == READ) | |
127 | memcpy(user_mem, (void *) phys_mem, vec->bv_len); | |
128 | else | |
129 | memcpy((void *) phys_mem, user_mem, vec->bv_len); | |
130 | ||
131 | phys_mem += vec->bv_len; | |
132 | transfered += vec->bv_len; | |
133 | } | |
134 | bio_endio(bio, transfered, 0); | |
135 | ||
136 | return rc; | |
137 | } | |
138 | ||
139 | /** | |
140 | * axon_ram_direct_access - direct_access() method for block device | |
141 | * @device, @sector, @data: see block_device_operations method | |
142 | */ | |
143 | static int | |
144 | axon_ram_direct_access(struct block_device *device, sector_t sector, | |
145 | unsigned long *data) | |
146 | { | |
147 | struct axon_ram_bank *bank = device->bd_disk->private_data; | |
148 | loff_t offset; | |
149 | ||
150 | offset = sector << AXON_RAM_SECTOR_SHIFT; | |
151 | if (offset >= bank->size) { | |
152 | dev_err(&bank->device->dev, "Access outside of address space\n"); | |
153 | return -ERANGE; | |
154 | } | |
155 | ||
156 | *data = bank->ph_addr + offset; | |
157 | ||
158 | return 0; | |
159 | } | |
160 | ||
161 | static struct block_device_operations axon_ram_devops = { | |
162 | .owner = THIS_MODULE, | |
163 | .direct_access = axon_ram_direct_access | |
164 | }; | |
165 | ||
166 | /** | |
167 | * axon_ram_probe - probe() method for platform driver | |
168 | * @device, @device_id: see of_platform_driver method | |
169 | */ | |
170 | static int | |
171 | axon_ram_probe(struct of_device *device, const struct of_device_id *device_id) | |
172 | { | |
173 | static int axon_ram_bank_id = -1; | |
174 | struct axon_ram_bank *bank; | |
175 | struct resource resource; | |
176 | int rc = 0; | |
177 | ||
178 | axon_ram_bank_id++; | |
179 | ||
180 | dev_info(&device->dev, "Found memory controller on %s\n", | |
181 | device->node->full_name); | |
182 | ||
183 | bank = kzalloc(sizeof(struct axon_ram_bank), GFP_KERNEL); | |
184 | if (bank == NULL) { | |
185 | dev_err(&device->dev, "Out of memory\n"); | |
186 | rc = -ENOMEM; | |
187 | goto failed; | |
188 | } | |
189 | ||
190 | device->dev.platform_data = bank; | |
191 | ||
192 | bank->device = device; | |
193 | ||
194 | if (of_address_to_resource(device->node, 0, &resource) != 0) { | |
195 | dev_err(&device->dev, "Cannot access device tree\n"); | |
196 | rc = -EFAULT; | |
197 | goto failed; | |
198 | } | |
199 | ||
200 | bank->size = resource.end - resource.start + 1; | |
201 | ||
202 | if (bank->size == 0) { | |
203 | dev_err(&device->dev, "No DDR2 memory found for %s%d\n", | |
204 | AXON_RAM_DEVICE_NAME, axon_ram_bank_id); | |
205 | rc = -ENODEV; | |
206 | goto failed; | |
207 | } | |
208 | ||
209 | dev_info(&device->dev, "Register DDR2 memory device %s%d with %luMB\n", | |
210 | AXON_RAM_DEVICE_NAME, axon_ram_bank_id, bank->size >> 20); | |
211 | ||
212 | bank->ph_addr = resource.start; | |
213 | bank->io_addr = (unsigned long) ioremap_flags( | |
214 | bank->ph_addr, bank->size, _PAGE_NO_CACHE); | |
215 | if (bank->io_addr == 0) { | |
216 | dev_err(&device->dev, "ioremap() failed\n"); | |
217 | rc = -EFAULT; | |
218 | goto failed; | |
219 | } | |
220 | ||
221 | bank->disk = alloc_disk(AXON_RAM_MINORS_PER_DISK); | |
222 | if (bank->disk == NULL) { | |
223 | dev_err(&device->dev, "Cannot register disk\n"); | |
224 | rc = -EFAULT; | |
225 | goto failed; | |
226 | } | |
227 | ||
228 | bank->disk->first_minor = 0; | |
229 | bank->disk->fops = &axon_ram_devops; | |
230 | bank->disk->private_data = bank; | |
231 | bank->disk->driverfs_dev = &device->dev; | |
232 | ||
233 | sprintf(bank->disk->disk_name, "%s%d", | |
234 | AXON_RAM_DEVICE_NAME, axon_ram_bank_id); | |
235 | bank->disk->major = register_blkdev(0, bank->disk->disk_name); | |
236 | if (bank->disk->major < 0) { | |
237 | dev_err(&device->dev, "Cannot register block device\n"); | |
238 | rc = -EFAULT; | |
239 | goto failed; | |
240 | } | |
241 | ||
242 | bank->disk->queue = blk_alloc_queue(GFP_KERNEL); | |
243 | if (bank->disk->queue == NULL) { | |
244 | dev_err(&device->dev, "Cannot register disk queue\n"); | |
245 | rc = -EFAULT; | |
246 | goto failed; | |
247 | } | |
248 | ||
249 | set_capacity(bank->disk, bank->size >> AXON_RAM_SECTOR_SHIFT); | |
250 | blk_queue_make_request(bank->disk->queue, axon_ram_make_request); | |
251 | blk_queue_hardsect_size(bank->disk->queue, AXON_RAM_SECTOR_SIZE); | |
252 | add_disk(bank->disk); | |
253 | ||
fedcd2c5 MS |
254 | bank->irq_id = irq_of_parse_and_map(device->node, 0); |
255 | if (bank->irq_id == NO_IRQ) { | |
dbdf04c4 MS |
256 | dev_err(&device->dev, "Cannot access ECC interrupt ID\n"); |
257 | rc = -EFAULT; | |
258 | goto failed; | |
259 | } | |
260 | ||
fedcd2c5 | 261 | rc = request_irq(bank->irq_id, axon_ram_irq_handler, |
dbdf04c4 MS |
262 | AXON_RAM_IRQ_FLAGS, bank->disk->disk_name, device); |
263 | if (rc != 0) { | |
264 | dev_err(&device->dev, "Cannot register ECC interrupt handler\n"); | |
fedcd2c5 | 265 | bank->irq_id = NO_IRQ; |
dbdf04c4 MS |
266 | rc = -EFAULT; |
267 | goto failed; | |
268 | } | |
269 | ||
270 | rc = device_create_file(&device->dev, &dev_attr_ecc); | |
271 | if (rc != 0) { | |
272 | dev_err(&device->dev, "Cannot create sysfs file\n"); | |
273 | rc = -EFAULT; | |
274 | goto failed; | |
275 | } | |
276 | ||
277 | return 0; | |
278 | ||
279 | failed: | |
280 | if (bank != NULL) { | |
fedcd2c5 MS |
281 | if (bank->irq_id != NO_IRQ) |
282 | free_irq(bank->irq_id, device); | |
dbdf04c4 | 283 | if (bank->disk != NULL) { |
dbdf04c4 MS |
284 | if (bank->disk->major > 0) |
285 | unregister_blkdev(bank->disk->major, | |
286 | bank->disk->disk_name); | |
287 | del_gendisk(bank->disk); | |
288 | } | |
289 | device->dev.platform_data = NULL; | |
290 | if (bank->io_addr != 0) | |
291 | iounmap((void __iomem *) bank->io_addr); | |
292 | kfree(bank); | |
293 | } | |
294 | ||
295 | return rc; | |
296 | } | |
297 | ||
298 | /** | |
299 | * axon_ram_remove - remove() method for platform driver | |
300 | * @device: see of_platform_driver method | |
301 | */ | |
302 | static int | |
303 | axon_ram_remove(struct of_device *device) | |
304 | { | |
305 | struct axon_ram_bank *bank = device->dev.platform_data; | |
306 | ||
307 | BUG_ON(!bank || !bank->disk); | |
308 | ||
309 | device_remove_file(&device->dev, &dev_attr_ecc); | |
fedcd2c5 | 310 | free_irq(bank->irq_id, device); |
dbdf04c4 MS |
311 | unregister_blkdev(bank->disk->major, bank->disk->disk_name); |
312 | del_gendisk(bank->disk); | |
313 | iounmap((void __iomem *) bank->io_addr); | |
314 | kfree(bank); | |
315 | ||
316 | return 0; | |
317 | } | |
318 | ||
319 | static struct of_device_id axon_ram_device_id[] = { | |
320 | { | |
321 | .type = "dma-memory" | |
322 | }, | |
323 | {} | |
324 | }; | |
325 | ||
326 | static struct of_platform_driver axon_ram_driver = { | |
dbdf04c4 MS |
327 | .match_table = axon_ram_device_id, |
328 | .probe = axon_ram_probe, | |
84dd4676 SR |
329 | .remove = axon_ram_remove, |
330 | .driver = { | |
331 | .owner = THIS_MODULE, | |
332 | .name = AXON_RAM_MODULE_NAME, | |
333 | }, | |
dbdf04c4 MS |
334 | }; |
335 | ||
336 | /** | |
337 | * axon_ram_init | |
338 | */ | |
339 | static int __init | |
340 | axon_ram_init(void) | |
341 | { | |
342 | return of_register_platform_driver(&axon_ram_driver); | |
343 | } | |
344 | ||
345 | /** | |
346 | * axon_ram_exit | |
347 | */ | |
348 | static void __exit | |
349 | axon_ram_exit(void) | |
350 | { | |
351 | of_unregister_platform_driver(&axon_ram_driver); | |
352 | } | |
353 | ||
354 | module_init(axon_ram_init); | |
355 | module_exit(axon_ram_exit); | |
356 | ||
357 | MODULE_LICENSE("GPL"); | |
358 | MODULE_AUTHOR("Maxim Shchetynin <maxim@de.ibm.com>"); | |
359 | MODULE_DESCRIPTION("Axon DDR2 RAM device driver for IBM Cell BE"); |