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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 <linux/of_device.h>
46#include <linux/of_platform.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
60static int azfs_major, azfs_minor;
61
62struct axon_ram_bank {
63 struct of_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
72static ssize_t
73axon_ram_sysfs_ecc(struct device *dev, struct device_attribute *attr, char *buf)
74{
75 struct of_device *device = to_of_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
83static DEVICE_ATTR(ecc, S_IRUGO, axon_ram_sysfs_ecc, NULL);
84
85
86
87
88
89
90static irqreturn_t
91axon_ram_irq_handler(int irq, void *dev)
92{
93 struct of_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 occured\n");
99 bank->ecc_counter++;
100 return IRQ_HANDLED;
101}
102
103
104
105
106
107static int
108axon_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 unsigned short idx;
116 int rc = 0;
117
118 phys_mem = bank->io_addr + (bio->bi_sector << AXON_RAM_SECTOR_SHIFT);
119 phys_end = bank->io_addr + bank->size;
120 transfered = 0;
121 bio_for_each_segment(vec, bio, idx) {
122 if (unlikely(phys_mem + vec->bv_len > phys_end)) {
123 bio_io_error(bio);
124 rc = -ERANGE;
125 break;
126 }
127
128 user_mem = page_address(vec->bv_page) + vec->bv_offset;
129 if (bio_data_dir(bio) == READ)
130 memcpy(user_mem, (void *) phys_mem, vec->bv_len);
131 else
132 memcpy((void *) phys_mem, user_mem, vec->bv_len);
133
134 phys_mem += vec->bv_len;
135 transfered += vec->bv_len;
136 }
137 bio_endio(bio, 0);
138
139 return rc;
140}
141
142
143
144
145
146static int
147axon_ram_direct_access(struct block_device *device, sector_t sector,
148 void **kaddr, unsigned long *pfn)
149{
150 struct axon_ram_bank *bank = device->bd_disk->private_data;
151 loff_t offset;
152
153 offset = sector;
154 if (device->bd_part != NULL)
155 offset += device->bd_part->start_sect;
156 offset <<= AXON_RAM_SECTOR_SHIFT;
157 if (offset >= bank->size) {
158 dev_err(&bank->device->dev, "Access outside of address space\n");
159 return -ERANGE;
160 }
161
162 *kaddr = (void *)(bank->ph_addr + offset);
163 *pfn = virt_to_phys(kaddr) >> PAGE_SHIFT;
164
165 return 0;
166}
167
168static const struct block_device_operations axon_ram_devops = {
169 .owner = THIS_MODULE,
170 .direct_access = axon_ram_direct_access
171};
172
173
174
175
176
177static int
178axon_ram_probe(struct of_device *device, const struct of_device_id *device_id)
179{
180 static int axon_ram_bank_id = -1;
181 struct axon_ram_bank *bank;
182 struct resource resource;
183 int rc = 0;
184
185 axon_ram_bank_id++;
186
187 dev_info(&device->dev, "Found memory controller on %s\n",
188 device->node->full_name);
189
190 bank = kzalloc(sizeof(struct axon_ram_bank), GFP_KERNEL);
191 if (bank == NULL) {
192 dev_err(&device->dev, "Out of memory\n");
193 rc = -ENOMEM;
194 goto failed;
195 }
196
197 device->dev.platform_data = bank;
198
199 bank->device = device;
200
201 if (of_address_to_resource(device->node, 0, &resource) != 0) {
202 dev_err(&device->dev, "Cannot access device tree\n");
203 rc = -EFAULT;
204 goto failed;
205 }
206
207 bank->size = resource.end - resource.start + 1;
208
209 if (bank->size == 0) {
210 dev_err(&device->dev, "No DDR2 memory found for %s%d\n",
211 AXON_RAM_DEVICE_NAME, axon_ram_bank_id);
212 rc = -ENODEV;
213 goto failed;
214 }
215
216 dev_info(&device->dev, "Register DDR2 memory device %s%d with %luMB\n",
217 AXON_RAM_DEVICE_NAME, axon_ram_bank_id, bank->size >> 20);
218
219 bank->ph_addr = resource.start;
220 bank->io_addr = (unsigned long) ioremap_flags(
221 bank->ph_addr, bank->size, _PAGE_NO_CACHE);
222 if (bank->io_addr == 0) {
223 dev_err(&device->dev, "ioremap() failed\n");
224 rc = -EFAULT;
225 goto failed;
226 }
227
228 bank->disk = alloc_disk(AXON_RAM_MINORS_PER_DISK);
229 if (bank->disk == NULL) {
230 dev_err(&device->dev, "Cannot register disk\n");
231 rc = -EFAULT;
232 goto failed;
233 }
234
235 bank->disk->major = azfs_major;
236 bank->disk->first_minor = azfs_minor;
237 bank->disk->fops = &axon_ram_devops;
238 bank->disk->private_data = bank;
239 bank->disk->driverfs_dev = &device->dev;
240
241 sprintf(bank->disk->disk_name, "%s%d",
242 AXON_RAM_DEVICE_NAME, axon_ram_bank_id);
243
244 bank->disk->queue = blk_alloc_queue(GFP_KERNEL);
245 if (bank->disk->queue == NULL) {
246 dev_err(&device->dev, "Cannot register disk queue\n");
247 rc = -EFAULT;
248 goto failed;
249 }
250
251 set_capacity(bank->disk, bank->size >> AXON_RAM_SECTOR_SHIFT);
252 blk_queue_make_request(bank->disk->queue, axon_ram_make_request);
253 blk_queue_logical_block_size(bank->disk->queue, AXON_RAM_SECTOR_SIZE);
254 add_disk(bank->disk);
255
256 bank->irq_id = irq_of_parse_and_map(device->node, 0);
257 if (bank->irq_id == NO_IRQ) {
258 dev_err(&device->dev, "Cannot access ECC interrupt ID\n");
259 rc = -EFAULT;
260 goto failed;
261 }
262
263 rc = request_irq(bank->irq_id, axon_ram_irq_handler,
264 AXON_RAM_IRQ_FLAGS, bank->disk->disk_name, device);
265 if (rc != 0) {
266 dev_err(&device->dev, "Cannot register ECC interrupt handler\n");
267 bank->irq_id = NO_IRQ;
268 rc = -EFAULT;
269 goto failed;
270 }
271
272 rc = device_create_file(&device->dev, &dev_attr_ecc);
273 if (rc != 0) {
274 dev_err(&device->dev, "Cannot create sysfs file\n");
275 rc = -EFAULT;
276 goto failed;
277 }
278
279 azfs_minor += bank->disk->minors;
280
281 return 0;
282
283failed:
284 if (bank != NULL) {
285 if (bank->irq_id != NO_IRQ)
286 free_irq(bank->irq_id, device);
287 if (bank->disk != NULL) {
288 if (bank->disk->major > 0)
289 unregister_blkdev(bank->disk->major,
290 bank->disk->disk_name);
291 del_gendisk(bank->disk);
292 }
293 device->dev.platform_data = NULL;
294 if (bank->io_addr != 0)
295 iounmap((void __iomem *) bank->io_addr);
296 kfree(bank);
297 }
298
299 return rc;
300}
301
302
303
304
305
306static int
307axon_ram_remove(struct of_device *device)
308{
309 struct axon_ram_bank *bank = device->dev.platform_data;
310
311 BUG_ON(!bank || !bank->disk);
312
313 device_remove_file(&device->dev, &dev_attr_ecc);
314 free_irq(bank->irq_id, device);
315 del_gendisk(bank->disk);
316 iounmap((void __iomem *) bank->io_addr);
317 kfree(bank);
318
319 return 0;
320}
321
322static struct of_device_id axon_ram_device_id[] = {
323 {
324 .type = "dma-memory"
325 },
326 {}
327};
328
329static struct of_platform_driver axon_ram_driver = {
330 .match_table = axon_ram_device_id,
331 .probe = axon_ram_probe,
332 .remove = axon_ram_remove,
333 .driver = {
334 .owner = THIS_MODULE,
335 .name = AXON_RAM_MODULE_NAME,
336 },
337};
338
339
340
341
342static int __init
343axon_ram_init(void)
344{
345 azfs_major = register_blkdev(azfs_major, AXON_RAM_DEVICE_NAME);
346 if (azfs_major < 0) {
347 printk(KERN_ERR "%s cannot become block device major number\n",
348 AXON_RAM_MODULE_NAME);
349 return -EFAULT;
350 }
351 azfs_minor = 0;
352
353 return of_register_platform_driver(&axon_ram_driver);
354}
355
356
357
358
359static void __exit
360axon_ram_exit(void)
361{
362 of_unregister_platform_driver(&axon_ram_driver);
363 unregister_blkdev(azfs_major, AXON_RAM_DEVICE_NAME);
364}
365
366module_init(axon_ram_init);
367module_exit(axon_ram_exit);
368
369MODULE_LICENSE("GPL");
370MODULE_AUTHOR("Maxim Shchetynin <maxim@de.ibm.com>");
371MODULE_DESCRIPTION("Axon DDR2 RAM device driver for IBM Cell BE");
372
