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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/device.h> | |
29 | #include <linux/errno.h> | |
30 | #include <linux/fs.h> | |
31 | #include <linux/genhd.h> | |
32 | #include <linux/interrupt.h> | |
33 | #include <linux/io.h> | |
34 | #include <linux/ioport.h> | |
35 | #include <linux/irq.h> | |
36 | #include <linux/irqreturn.h> | |
37 | #include <linux/kernel.h> | |
38 | #include <linux/mm.h> | |
39 | #include <linux/mod_devicetable.h> | |
40 | #include <linux/module.h> | |
41 | #include <linux/slab.h> | |
42 | #include <linux/string.h> | |
43 | #include <linux/types.h> | |
44 | #include <linux/of_device.h> | |
45 | #include <linux/of_platform.h> | |
46 | #include <linux/pfn_t.h> | |
47 | ||
48 | #include <asm/page.h> | |
49 | #include <asm/prom.h> | |
50 | ||
51 | #define AXON_RAM_MODULE_NAME "axonram" | |
52 | #define AXON_RAM_DEVICE_NAME "axonram" | |
53 | #define AXON_RAM_MINORS_PER_DISK 16 | |
54 | #define AXON_RAM_BLOCK_SHIFT PAGE_SHIFT | |
55 | #define AXON_RAM_BLOCK_SIZE 1 << AXON_RAM_BLOCK_SHIFT | |
56 | #define AXON_RAM_SECTOR_SHIFT 9 | |
57 | #define AXON_RAM_SECTOR_SIZE 1 << AXON_RAM_SECTOR_SHIFT | |
58 | #define AXON_RAM_IRQ_FLAGS IRQF_SHARED | IRQF_TRIGGER_RISING | |
59 | ||
60 | static int azfs_major, azfs_minor; | |
61 | ||
62 | struct axon_ram_bank { | |
63 | struct platform_device *device; | |
64 | struct gendisk *disk; | |
65 | unsigned int irq_id; | |
66 | unsigned long ph_addr; | |
67 | unsigned long io_addr; | |
68 | unsigned long size; | |
69 | unsigned long ecc_counter; | |
70 | }; | |
71 | ||
72 | static ssize_t | |
73 | axon_ram_sysfs_ecc(struct device *dev, struct device_attribute *attr, char *buf) | |
74 | { | |
75 | struct platform_device *device = to_platform_device(dev); | |
76 | struct axon_ram_bank *bank = device->dev.platform_data; | |
77 | ||
78 | BUG_ON(!bank); | |
79 | ||
80 | return sprintf(buf, "%ld\n", bank->ecc_counter); | |
81 | } | |
82 | ||
83 | static DEVICE_ATTR(ecc, S_IRUGO, axon_ram_sysfs_ecc, NULL); | |
84 | ||
85 | /** | |
86 | * axon_ram_irq_handler - interrupt handler for Axon RAM ECC | |
87 | * @irq: interrupt ID | |
88 | * @dev: pointer to of_device | |
89 | */ | |
90 | static irqreturn_t | |
91 | axon_ram_irq_handler(int irq, void *dev) | |
92 | { | |
93 | struct platform_device *device = dev; | |
94 | struct axon_ram_bank *bank = device->dev.platform_data; | |
95 | ||
96 | BUG_ON(!bank); | |
97 | ||
98 | dev_err(&device->dev, "Correctable memory error occurred\n"); | |
99 | bank->ecc_counter++; | |
100 | return IRQ_HANDLED; | |
101 | } | |
102 | ||
103 | /** | |
104 | * axon_ram_make_request - make_request() method for block device | |
105 | * @queue, @bio: see blk_queue_make_request() | |
106 | */ | |
107 | static blk_qc_t | |
108 | axon_ram_make_request(struct request_queue *queue, struct bio *bio) | |
109 | { | |
110 | struct axon_ram_bank *bank = bio->bi_bdev->bd_disk->private_data; | |
111 | unsigned long phys_mem, phys_end; | |
112 | void *user_mem; | |
113 | struct bio_vec vec; | |
114 | unsigned int transfered; | |
115 | struct bvec_iter iter; | |
116 | ||
117 | phys_mem = bank->io_addr + (bio->bi_iter.bi_sector << | |
118 | AXON_RAM_SECTOR_SHIFT); | |
119 | phys_end = bank->io_addr + bank->size; | |
120 | transfered = 0; | |
121 | bio_for_each_segment(vec, bio, iter) { | |
122 | if (unlikely(phys_mem + vec.bv_len > phys_end)) { | |
123 | bio_io_error(bio); | |
124 | return BLK_QC_T_NONE; | |
125 | } | |
126 | ||
127 | user_mem = page_address(vec.bv_page) + vec.bv_offset; | |
128 | if (bio_data_dir(bio) == READ) | |
129 | memcpy(user_mem, (void *) phys_mem, vec.bv_len); | |
130 | else | |
131 | memcpy((void *) phys_mem, user_mem, vec.bv_len); | |
132 | ||
133 | phys_mem += vec.bv_len; | |
134 | transfered += vec.bv_len; | |
135 | } | |
136 | bio_endio(bio); | |
137 | return BLK_QC_T_NONE; | |
138 | } | |
139 | ||
140 | /** | |
141 | * axon_ram_direct_access - direct_access() method for block device | |
142 | * @device, @sector, @data: see block_device_operations method | |
143 | */ | |
144 | static long | |
145 | axon_ram_direct_access(struct block_device *device, sector_t sector, | |
146 | void __pmem **kaddr, pfn_t *pfn, long size) | |
147 | { | |
148 | struct axon_ram_bank *bank = device->bd_disk->private_data; | |
149 | loff_t offset = (loff_t)sector << AXON_RAM_SECTOR_SHIFT; | |
150 | ||
151 | *kaddr = (void __pmem __force *) bank->io_addr + offset; | |
152 | *pfn = phys_to_pfn_t(bank->ph_addr + offset, PFN_DEV); | |
153 | return bank->size - offset; | |
154 | } | |
155 | ||
156 | static const struct block_device_operations axon_ram_devops = { | |
157 | .owner = THIS_MODULE, | |
158 | .direct_access = axon_ram_direct_access | |
159 | }; | |
160 | ||
161 | /** | |
162 | * axon_ram_probe - probe() method for platform driver | |
163 | * @device: see platform_driver method | |
164 | */ | |
165 | static int axon_ram_probe(struct platform_device *device) | |
166 | { | |
167 | static int axon_ram_bank_id = -1; | |
168 | struct axon_ram_bank *bank; | |
169 | struct resource resource; | |
170 | int rc = 0; | |
171 | ||
172 | axon_ram_bank_id++; | |
173 | ||
174 | dev_info(&device->dev, "Found memory controller on %s\n", | |
175 | device->dev.of_node->full_name); | |
176 | ||
177 | bank = kzalloc(sizeof(struct axon_ram_bank), GFP_KERNEL); | |
178 | if (bank == NULL) { | |
179 | dev_err(&device->dev, "Out of memory\n"); | |
180 | rc = -ENOMEM; | |
181 | goto failed; | |
182 | } | |
183 | ||
184 | device->dev.platform_data = bank; | |
185 | ||
186 | bank->device = device; | |
187 | ||
188 | if (of_address_to_resource(device->dev.of_node, 0, &resource) != 0) { | |
189 | dev_err(&device->dev, "Cannot access device tree\n"); | |
190 | rc = -EFAULT; | |
191 | goto failed; | |
192 | } | |
193 | ||
194 | bank->size = resource_size(&resource); | |
195 | ||
196 | if (bank->size == 0) { | |
197 | dev_err(&device->dev, "No DDR2 memory found for %s%d\n", | |
198 | AXON_RAM_DEVICE_NAME, axon_ram_bank_id); | |
199 | rc = -ENODEV; | |
200 | goto failed; | |
201 | } | |
202 | ||
203 | dev_info(&device->dev, "Register DDR2 memory device %s%d with %luMB\n", | |
204 | AXON_RAM_DEVICE_NAME, axon_ram_bank_id, bank->size >> 20); | |
205 | ||
206 | bank->ph_addr = resource.start; | |
207 | bank->io_addr = (unsigned long) ioremap_prot( | |
208 | bank->ph_addr, bank->size, _PAGE_NO_CACHE); | |
209 | if (bank->io_addr == 0) { | |
210 | dev_err(&device->dev, "ioremap() failed\n"); | |
211 | rc = -EFAULT; | |
212 | goto failed; | |
213 | } | |
214 | ||
215 | bank->disk = alloc_disk(AXON_RAM_MINORS_PER_DISK); | |
216 | if (bank->disk == NULL) { | |
217 | dev_err(&device->dev, "Cannot register disk\n"); | |
218 | rc = -EFAULT; | |
219 | goto failed; | |
220 | } | |
221 | ||
222 | bank->disk->major = azfs_major; | |
223 | bank->disk->first_minor = azfs_minor; | |
224 | bank->disk->fops = &axon_ram_devops; | |
225 | bank->disk->private_data = bank; | |
226 | ||
227 | sprintf(bank->disk->disk_name, "%s%d", | |
228 | AXON_RAM_DEVICE_NAME, axon_ram_bank_id); | |
229 | ||
230 | bank->disk->queue = blk_alloc_queue(GFP_KERNEL); | |
231 | if (bank->disk->queue == NULL) { | |
232 | dev_err(&device->dev, "Cannot register disk queue\n"); | |
233 | rc = -EFAULT; | |
234 | goto failed; | |
235 | } | |
236 | ||
237 | set_capacity(bank->disk, bank->size >> AXON_RAM_SECTOR_SHIFT); | |
238 | blk_queue_make_request(bank->disk->queue, axon_ram_make_request); | |
239 | blk_queue_logical_block_size(bank->disk->queue, AXON_RAM_SECTOR_SIZE); | |
240 | device_add_disk(&device->dev, bank->disk); | |
241 | ||
242 | bank->irq_id = irq_of_parse_and_map(device->dev.of_node, 0); | |
243 | if (bank->irq_id == NO_IRQ) { | |
244 | dev_err(&device->dev, "Cannot access ECC interrupt ID\n"); | |
245 | rc = -EFAULT; | |
246 | goto failed; | |
247 | } | |
248 | ||
249 | rc = request_irq(bank->irq_id, axon_ram_irq_handler, | |
250 | AXON_RAM_IRQ_FLAGS, bank->disk->disk_name, device); | |
251 | if (rc != 0) { | |
252 | dev_err(&device->dev, "Cannot register ECC interrupt handler\n"); | |
253 | bank->irq_id = NO_IRQ; | |
254 | rc = -EFAULT; | |
255 | goto failed; | |
256 | } | |
257 | ||
258 | rc = device_create_file(&device->dev, &dev_attr_ecc); | |
259 | if (rc != 0) { | |
260 | dev_err(&device->dev, "Cannot create sysfs file\n"); | |
261 | rc = -EFAULT; | |
262 | goto failed; | |
263 | } | |
264 | ||
265 | azfs_minor += bank->disk->minors; | |
266 | ||
267 | return 0; | |
268 | ||
269 | failed: | |
270 | if (bank != NULL) { | |
271 | if (bank->irq_id != NO_IRQ) | |
272 | free_irq(bank->irq_id, device); | |
273 | if (bank->disk != NULL) { | |
274 | if (bank->disk->major > 0) | |
275 | unregister_blkdev(bank->disk->major, | |
276 | bank->disk->disk_name); | |
277 | del_gendisk(bank->disk); | |
278 | } | |
279 | device->dev.platform_data = NULL; | |
280 | if (bank->io_addr != 0) | |
281 | iounmap((void __iomem *) bank->io_addr); | |
282 | kfree(bank); | |
283 | } | |
284 | ||
285 | return rc; | |
286 | } | |
287 | ||
288 | /** | |
289 | * axon_ram_remove - remove() method for platform driver | |
290 | * @device: see of_platform_driver method | |
291 | */ | |
292 | static int | |
293 | axon_ram_remove(struct platform_device *device) | |
294 | { | |
295 | struct axon_ram_bank *bank = device->dev.platform_data; | |
296 | ||
297 | BUG_ON(!bank || !bank->disk); | |
298 | ||
299 | device_remove_file(&device->dev, &dev_attr_ecc); | |
300 | free_irq(bank->irq_id, device); | |
301 | del_gendisk(bank->disk); | |
302 | iounmap((void __iomem *) bank->io_addr); | |
303 | kfree(bank); | |
304 | ||
305 | return 0; | |
306 | } | |
307 | ||
308 | static const struct of_device_id axon_ram_device_id[] = { | |
309 | { | |
310 | .type = "dma-memory" | |
311 | }, | |
312 | {} | |
313 | }; | |
314 | MODULE_DEVICE_TABLE(of, axon_ram_device_id); | |
315 | ||
316 | static struct platform_driver axon_ram_driver = { | |
317 | .probe = axon_ram_probe, | |
318 | .remove = axon_ram_remove, | |
319 | .driver = { | |
320 | .name = AXON_RAM_MODULE_NAME, | |
321 | .of_match_table = axon_ram_device_id, | |
322 | }, | |
323 | }; | |
324 | ||
325 | /** | |
326 | * axon_ram_init | |
327 | */ | |
328 | static int __init | |
329 | axon_ram_init(void) | |
330 | { | |
331 | azfs_major = register_blkdev(azfs_major, AXON_RAM_DEVICE_NAME); | |
332 | if (azfs_major < 0) { | |
333 | printk(KERN_ERR "%s cannot become block device major number\n", | |
334 | AXON_RAM_MODULE_NAME); | |
335 | return -EFAULT; | |
336 | } | |
337 | azfs_minor = 0; | |
338 | ||
339 | return platform_driver_register(&axon_ram_driver); | |
340 | } | |
341 | ||
342 | /** | |
343 | * axon_ram_exit | |
344 | */ | |
345 | static void __exit | |
346 | axon_ram_exit(void) | |
347 | { | |
348 | platform_driver_unregister(&axon_ram_driver); | |
349 | unregister_blkdev(azfs_major, AXON_RAM_DEVICE_NAME); | |
350 | } | |
351 | ||
352 | module_init(axon_ram_init); | |
353 | module_exit(axon_ram_exit); | |
354 | ||
355 | MODULE_LICENSE("GPL"); | |
356 | MODULE_AUTHOR("Maxim Shchetynin <maxim@de.ibm.com>"); | |
357 | MODULE_DESCRIPTION("Axon DDR2 RAM device driver for IBM Cell BE"); |