1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
|
/*
* (C) Copyright IBM Deutschland Entwicklung GmbH 2006
*
* Author: Maxim Shchetynin <maxim@de.ibm.com>
*
* Axon DDR2 device driver.
* It registers one block device per Axon's DDR2 memory bank found on a system.
* Block devices are called axonram?, their major and minor numbers are
* available in /proc/devices, /proc/partitions or in /sys/block/axonram?/dev.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/bio.h>
#include <linux/blkdev.h>
#include <linux/buffer_head.h>
#include <linux/device.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/genhd.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/irq.h>
#include <linux/irqreturn.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/of_device.h>
#include <linux/of_platform.h>
#include <asm/page.h>
#include <asm/prom.h>
#define AXON_RAM_MODULE_NAME "axonram"
#define AXON_RAM_DEVICE_NAME "axonram"
#define AXON_RAM_MINORS_PER_DISK 16
#define AXON_RAM_BLOCK_SHIFT PAGE_SHIFT
#define AXON_RAM_BLOCK_SIZE 1 << AXON_RAM_BLOCK_SHIFT
#define AXON_RAM_SECTOR_SHIFT 9
#define AXON_RAM_SECTOR_SIZE 1 << AXON_RAM_SECTOR_SHIFT
#define AXON_RAM_IRQ_FLAGS IRQF_SHARED | IRQF_TRIGGER_RISING
static int azfs_major, azfs_minor;
struct axon_ram_bank {
struct of_device *device;
struct gendisk *disk;
unsigned int irq_id;
unsigned long ph_addr;
unsigned long io_addr;
unsigned long size;
unsigned long ecc_counter;
};
static ssize_t
axon_ram_sysfs_ecc(struct device *dev, struct device_attribute *attr, char *buf)
{
struct of_device *device = to_of_device(dev);
struct axon_ram_bank *bank = device->dev.platform_data;
BUG_ON(!bank);
return sprintf(buf, "%ld\n", bank->ecc_counter);
}
static DEVICE_ATTR(ecc, S_IRUGO, axon_ram_sysfs_ecc, NULL);
/**
* axon_ram_irq_handler - interrupt handler for Axon RAM ECC
* @irq: interrupt ID
* @dev: pointer to of_device
*/
static irqreturn_t
axon_ram_irq_handler(int irq, void *dev)
{
struct of_device *device = dev;
struct axon_ram_bank *bank = device->dev.platform_data;
BUG_ON(!bank);
dev_err(&device->dev, "Correctable memory error occured\n");
bank->ecc_counter++;
return IRQ_HANDLED;
}
/**
* axon_ram_make_request - make_request() method for block device
* @queue, @bio: see blk_queue_make_request()
*/
static int
axon_ram_make_request(struct request_queue *queue, struct bio *bio)
{
struct axon_ram_bank *bank = bio->bi_bdev->bd_disk->private_data;
unsigned long phys_mem, phys_end;
void *user_mem;
struct bio_vec *vec;
unsigned int transfered;
unsigned short idx;
int rc = 0;
phys_mem = bank->io_addr + (bio->bi_sector << AXON_RAM_SECTOR_SHIFT);
phys_end = bank->io_addr + bank->size;
transfered = 0;
bio_for_each_segment(vec, bio, idx) {
if (unlikely(phys_mem + vec->bv_len > phys_end)) {
bio_io_error(bio);
rc = -ERANGE;
break;
}
user_mem = page_address(vec->bv_page) + vec->bv_offset;
if (bio_data_dir(bio) == READ)
memcpy(user_mem, (void *) phys_mem, vec->bv_len);
else
memcpy((void *) phys_mem, user_mem, vec->bv_len);
phys_mem += vec->bv_len;
transfered += vec->bv_len;
}
bio_endio(bio, 0);
return rc;
}
/**
* axon_ram_direct_access - direct_access() method for block device
* @device, @sector, @data: see block_device_operations method
*/
static int
axon_ram_direct_access(struct block_device *device, sector_t sector,
void **kaddr, unsigned long *pfn)
{
struct axon_ram_bank *bank = device->bd_disk->private_data;
loff_t offset;
offset = sector;
if (device->bd_part != NULL)
offset += device->bd_part->start_sect;
offset <<= AXON_RAM_SECTOR_SHIFT;
if (offset >= bank->size) {
dev_err(&bank->device->dev, "Access outside of address space\n");
return -ERANGE;
}
*kaddr = (void *)(bank->ph_addr + offset);
*pfn = virt_to_phys(kaddr) >> PAGE_SHIFT;
return 0;
}
static struct block_device_operations axon_ram_devops = {
.owner = THIS_MODULE,
.direct_access = axon_ram_direct_access
};
/**
* axon_ram_probe - probe() method for platform driver
* @device, @device_id: see of_platform_driver method
*/
static int
axon_ram_probe(struct of_device *device, const struct of_device_id *device_id)
{
static int axon_ram_bank_id = -1;
struct axon_ram_bank *bank;
struct resource resource;
int rc = 0;
axon_ram_bank_id++;
dev_info(&device->dev, "Found memory controller on %s\n",
device->node->full_name);
bank = kzalloc(sizeof(struct axon_ram_bank), GFP_KERNEL);
if (bank == NULL) {
dev_err(&device->dev, "Out of memory\n");
rc = -ENOMEM;
goto failed;
}
device->dev.platform_data = bank;
bank->device = device;
if (of_address_to_resource(device->node, 0, &resource) != 0) {
dev_err(&device->dev, "Cannot access device tree\n");
rc = -EFAULT;
goto failed;
}
bank->size = resource.end - resource.start + 1;
if (bank->size == 0) {
dev_err(&device->dev, "No DDR2 memory found for %s%d\n",
AXON_RAM_DEVICE_NAME, axon_ram_bank_id);
rc = -ENODEV;
goto failed;
}
dev_info(&device->dev, "Register DDR2 memory device %s%d with %luMB\n",
AXON_RAM_DEVICE_NAME, axon_ram_bank_id, bank->size >> 20);
bank->ph_addr = resource.start;
bank->io_addr = (unsigned long) ioremap_flags(
bank->ph_addr, bank->size, _PAGE_NO_CACHE);
if (bank->io_addr == 0) {
dev_err(&device->dev, "ioremap() failed\n");
rc = -EFAULT;
goto failed;
}
bank->disk = alloc_disk(AXON_RAM_MINORS_PER_DISK);
if (bank->disk == NULL) {
dev_err(&device->dev, "Cannot register disk\n");
rc = -EFAULT;
goto failed;
}
bank->disk->major = azfs_major;
bank->disk->first_minor = azfs_minor;
bank->disk->fops = &axon_ram_devops;
bank->disk->private_data = bank;
bank->disk->driverfs_dev = &device->dev;
sprintf(bank->disk->disk_name, "%s%d",
AXON_RAM_DEVICE_NAME, axon_ram_bank_id);
bank->disk->queue = blk_alloc_queue(GFP_KERNEL);
if (bank->disk->queue == NULL) {
dev_err(&device->dev, "Cannot register disk queue\n");
rc = -EFAULT;
goto failed;
}
set_capacity(bank->disk, bank->size >> AXON_RAM_SECTOR_SHIFT);
blk_queue_make_request(bank->disk->queue, axon_ram_make_request);
blk_queue_hardsect_size(bank->disk->queue, AXON_RAM_SECTOR_SIZE);
add_disk(bank->disk);
bank->irq_id = irq_of_parse_and_map(device->node, 0);
if (bank->irq_id == NO_IRQ) {
dev_err(&device->dev, "Cannot access ECC interrupt ID\n");
rc = -EFAULT;
goto failed;
}
rc = request_irq(bank->irq_id, axon_ram_irq_handler,
AXON_RAM_IRQ_FLAGS, bank->disk->disk_name, device);
if (rc != 0) {
dev_err(&device->dev, "Cannot register ECC interrupt handler\n");
bank-
|