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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
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
59static int azfs_major, azfs_minor;
60
61struct axon_ram_bank {
62 struct platform_device *device;
63 struct gendisk *disk;
64 unsigned int irq_id;
65 unsigned long ph_addr;
66 unsigned long io_addr;
67 unsigned long size;
68 unsigned long ecc_counter;
69};
70
71static ssize_t
72axon_ram_sysfs_ecc(struct device *dev, struct device_attribute *attr, char *buf)
73{
74 struct platform_device *device = to_platform_device(dev);
75 struct axon_ram_bank *bank = device->dev.platform_data;
76
77 BUG_ON(!bank);
78
79 return sprintf(buf, "%ld\n", bank->ecc_counter);
80}
81
82static DEVICE_ATTR(ecc, S_IRUGO, axon_ram_sysfs_ecc, NULL);
83
84
85
86
87
88
89static irqreturn_t
90axon_ram_irq_handler(int irq, void *dev)
91{
92 struct platform_device *device = dev;
93 struct axon_ram_bank *bank = device->dev.platform_data;
94
95 BUG_ON(!bank);
96
97 dev_err(&device->dev, "Correctable memory error occurred\n");
98 bank->ecc_counter++;
99 return IRQ_HANDLED;
100}
101
102
103
104
105
106static void
107axon_ram_make_request(struct request_queue *queue, struct bio *bio)
108{
109 struct axon_ram_bank *bank = bio->bi_bdev->bd_disk->private_data;
110 unsigned long phys_mem, phys_end;
111 void *user_mem;
112 struct bio_vec vec;
113 unsigned int transfered;
114 struct bvec_iter iter;
115
116 phys_mem = bank->io_addr + (bio->bi_iter.bi_sector <<
117 AXON_RAM_SECTOR_SHIFT);
118 phys_end = bank->io_addr + bank->size;
119 transfered = 0;
120 bio_for_each_segment(vec, bio, iter) {
121 if (unlikely(phys_mem + vec.bv_len > phys_end)) {
122 bio_io_error(bio);
123 return;
124 }
125
126 user_mem = page_address(vec.bv_page) + vec.bv_offset;
127 if (bio_data_dir(bio) == READ)
128 memcpy(user_mem, (void *) phys_mem, vec.bv_len);
129 else
130 memcpy((void *) phys_mem, user_mem, vec.bv_len);
131
132 phys_mem += vec.bv_len;
133 transfered += vec.bv_len;
134 }
135 bio_endio(bio, 0);
136}
137
138
139
140
141
142static int
143axon_ram_direct_access(struct block_device *device, sector_t sector,
144 void **kaddr, unsigned long *pfn)
145{
146 struct axon_ram_bank *bank = device->bd_disk->private_data;
147 loff_t offset;
148
149 offset = sector;
150 if (device->bd_part != NULL)
151 offset += device->bd_part->start_sect;
152 offset <<= AXON_RAM_SECTOR_SHIFT;
153 if (offset >= bank->size) {
154 dev_err(&bank->device->dev, "Access outside of address space\n");
155 return -ERANGE;
156 }
157
158 *kaddr = (void *)(bank->ph_addr + offset);
159 *pfn = virt_to_phys(kaddr) >> PAGE_SHIFT;
160
161 return 0;
162}
163
164static const struct block_device_operations axon_ram_devops = {
165 .owner = THIS_MODULE,
166 .direct_access = axon_ram_direct_access
167};
168
169
170
171
172
173static int axon_ram_probe(struct platform_device *device)
174{
175 static int axon_ram_bank_id = -1;
176 struct axon_ram_bank *bank;
177 struct resource resource;
178 int rc = 0;
179
180 axon_ram_bank_id++;
181
182 dev_info(&device->dev, "Found memory controller on %s\n",
183 device->dev.of_node->full_name);
184
185 bank = kzalloc(sizeof(struct axon_ram_bank), GFP_KERNEL);
186 if (bank == NULL) {
187 dev_err(&device->dev, "Out of memory\n");
188 rc = -ENOMEM;
189 goto failed;
190 }
191
192 device->dev.platform_data = bank;
193
194 bank->device = device;
195
196 if (of_address_to_resource(device->dev.of_node, 0, &resource) != 0) {
197 dev_err(&device->dev, "Cannot access device tree\n");
198 rc = -EFAULT;
199 goto failed;
200 }
201
202 bank->size = resource_size(&resource);
203
204 if (bank->size == 0) {
205 dev_err(&device->dev, "No DDR2 memory found for %s%d\n",
206 AXON_RAM_DEVICE_NAME, axon_ram_bank_id);
207 rc = -ENODEV;
208 goto failed;
209 }
210
211 dev_info(&device->dev, "Register DDR2 memory device %s%d with %luMB\n",
212 AXON_RAM_DEVICE_NAME, axon_ram_bank_id, bank->size >> 20);
213
214 bank->ph_addr = resource.start;
215 bank->io_addr = (unsigned long) ioremap_prot(
216 bank->ph_addr, bank->size, _PAGE_NO_CACHE);
217 if (bank->io_addr == 0) {
218 dev_err(&device->dev, "ioremap() failed\n");
219 rc = -EFAULT;
220 goto failed;
221 }
222
223 bank->disk = alloc_disk(AXON_RAM_MINORS_PER_DISK);
224 if (bank->disk == NULL) {
225 dev_err(&device->dev, "Cannot register disk\n");
226 rc = -EFAULT;
227 goto failed;
228 }
229
230 bank->disk->major = azfs_major;
231 bank->disk->first_minor = azfs_minor;
232 bank->disk->fops = &axon_ram_devops;
233 bank->disk->private_data = bank;
234 bank->disk->driverfs_dev = &device->dev;
235
236 sprintf(bank->disk->disk_name, "%s%d",
237 AXON_RAM_DEVICE_NAME, axon_ram_bank_id);
238
239 bank->disk->queue = blk_alloc_queue(GFP_KERNEL);
240 if (bank->disk->queue == NULL) {
241 dev_err(&device->dev, "Cannot register disk queue\n");
242 rc = -EFAULT;
243 goto failed;
244 }
245
246 set_capacity(bank->disk, bank->size >> AXON_RAM_SECTOR_SHIFT);
247 blk_queue_make_request(bank->disk->queue, axon_ram_make_request);
248 blk_queue_logical_block_size(bank->disk->queue, AXON_RAM_SECTOR_SIZE);
249 add_disk(bank->disk);
250
251 bank->irq_id = irq_of_parse_and_map(device->dev.of_node, 0);
252 if (bank->irq_id == NO_IRQ) {
253 dev_err(&device->dev, "Cannot access ECC interrupt ID\n");
254 rc = -EFAULT;
255 goto failed;
256 }
257
258 rc = request_irq(bank->irq_id, axon_ram_irq_handler,
259 AXON_RAM_IRQ_FLAGS, bank->disk->disk_name, device);
260 if (rc != 0) {
261 dev_err(&device->dev, "Cannot register ECC interrupt handler\n");
262 bank->irq_id = NO_IRQ;
263 rc = -EFAULT;
264 goto failed;
265 }
266
267 rc = device_create_file(&device->dev, &dev_attr_ecc);
268 if (rc != 0) {
269 dev_err(&device->dev, "Cannot create sysfs file\n");
270 rc = -EFAULT;
271 goto failed;
272 }
273
274 azfs_minor += bank->disk->minors;
275
276 return 0;
277
278failed:
279 if (bank != NULL) {
280 if (bank->irq_id != NO_IRQ)
281 free_irq(bank->irq_id, device);
282 if (bank->disk != NULL) {
283 if (bank->disk->major > 0)
284 unregister_blkdev(bank->disk->major,
285 bank->disk->disk_name);
286 del_gendisk(bank->disk);
287 }
288 device->dev.platform_data = NULL;
289 if (bank->io_addr != 0)
290 iounmap((void __iomem *) bank->io_addr);
291 kfree(bank);
292 }
293
294 return rc;
295}
296
297
298
299
300
301static int
302axon_ram_remove(struct platform_device *device)
303{
304 struct axon_ram_bank *bank = device->dev.platform_data;
305
306 BUG_ON(!bank || !bank->disk);
307
308 device_remove_file(&device->dev, &dev_attr_ecc);
309 free_irq(bank->irq_id, device);
310 del_gendisk(bank->disk);
311 iounmap((void __iomem *) bank->io_addr);
312 kfree(bank);
313
314 return 0;
315}
316
317static struct of_device_id axon_ram_device_id[] = {
318 {
319 .type = "dma-memory"
320 },
321 {}
322};
323
324static struct platform_driver axon_ram_driver = {
325 .probe = axon_ram_probe,
326 .remove = axon_ram_remove,
327 .driver = {
328 .name = AXON_RAM_MODULE_NAME,
329 .owner = THIS_MODULE,
330 .of_match_table = axon_ram_device_id,
331 },
332};
333
334
335
336
337static int __init
338axon_ram_init(void)
339{
340 azfs_major = register_blkdev(azfs_major, AXON_RAM_DEVICE_NAME);
341 if (azfs_major < 0) {
342 printk(KERN_ERR "%s cannot become block device major number\n",
343 AXON_RAM_MODULE_NAME);
344 return -EFAULT;
345 }
346 azfs_minor = 0;
347
348 return platform_driver_register(&axon_ram_driver);
349}
350
351
352
353
354static void __exit
355axon_ram_exit(void)
356{
357 platform_driver_unregister(&axon_ram_driver);
358 unregister_blkdev(azfs_major, AXON_RAM_DEVICE_NAME);
359}
360
361module_init(axon_ram_init);
362module_exit(axon_ram_exit);
363
364MODULE_LICENSE("GPL");
365MODULE_AUTHOR("Maxim Shchetynin <maxim@de.ibm.com>");
366MODULE_DESCRIPTION("Axon DDR2 RAM device driver for IBM Cell BE");
367
