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26#include <linux/bio.h>
27#include <linux/blkdev.h>
28#include <linux/dax.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#include <linux/pfn_t.h>
48#include <linux/uio.h>
49
50#include <asm/page.h>
51#include <asm/prom.h>
52
53#define AXON_RAM_MODULE_NAME "axonram"
54#define AXON_RAM_DEVICE_NAME "axonram"
55#define AXON_RAM_MINORS_PER_DISK 16
56#define AXON_RAM_BLOCK_SHIFT PAGE_SHIFT
57#define AXON_RAM_BLOCK_SIZE 1 << AXON_RAM_BLOCK_SHIFT
58#define AXON_RAM_SECTOR_SHIFT 9
59#define AXON_RAM_SECTOR_SIZE 1 << AXON_RAM_SECTOR_SHIFT
60#define AXON_RAM_IRQ_FLAGS IRQF_SHARED | IRQF_TRIGGER_RISING
61
62static int azfs_major, azfs_minor;
63
64struct axon_ram_bank {
65 struct platform_device *device;
66 struct gendisk *disk;
67 struct dax_device *dax_dev;
68 unsigned int irq_id;
69 unsigned long ph_addr;
70 unsigned long io_addr;
71 unsigned long size;
72 unsigned long ecc_counter;
73};
74
75static ssize_t
76axon_ram_sysfs_ecc(struct device *dev, struct device_attribute *attr, char *buf)
77{
78 struct platform_device *device = to_platform_device(dev);
79 struct axon_ram_bank *bank = device->dev.platform_data;
80
81 BUG_ON(!bank);
82
83 return sprintf(buf, "%ld\n", bank->ecc_counter);
84}
85
86static DEVICE_ATTR(ecc, S_IRUGO, axon_ram_sysfs_ecc, NULL);
87
88
89
90
91
92
93static irqreturn_t
94axon_ram_irq_handler(int irq, void *dev)
95{
96 struct platform_device *device = dev;
97 struct axon_ram_bank *bank = device->dev.platform_data;
98
99 BUG_ON(!bank);
100
101 dev_err(&device->dev, "Correctable memory error occurred\n");
102 bank->ecc_counter++;
103 return IRQ_HANDLED;
104}
105
106
107
108
109
110static blk_qc_t
111axon_ram_make_request(struct request_queue *queue, struct bio *bio)
112{
113 struct axon_ram_bank *bank = bio->bi_disk->private_data;
114 unsigned long phys_mem, phys_end;
115 void *user_mem;
116 struct bio_vec vec;
117 unsigned int transfered;
118 struct bvec_iter iter;
119
120 phys_mem = bank->io_addr + (bio->bi_iter.bi_sector <<
121 AXON_RAM_SECTOR_SHIFT);
122 phys_end = bank->io_addr + bank->size;
123 transfered = 0;
124 bio_for_each_segment(vec, bio, iter) {
125 if (unlikely(phys_mem + vec.bv_len > phys_end)) {
126 bio_io_error(bio);
127 return BLK_QC_T_NONE;
128 }
129
130 user_mem = page_address(vec.bv_page) + vec.bv_offset;
131 if (bio_data_dir(bio) == READ)
132 memcpy(user_mem, (void *) phys_mem, vec.bv_len);
133 else
134 memcpy((void *) phys_mem, user_mem, vec.bv_len);
135
136 phys_mem += vec.bv_len;
137 transfered += vec.bv_len;
138 }
139 bio_endio(bio);
140 return BLK_QC_T_NONE;
141}
142
143static const struct block_device_operations axon_ram_devops = {
144 .owner = THIS_MODULE,
145};
146
147static long
148__axon_ram_direct_access(struct axon_ram_bank *bank, pgoff_t pgoff, long nr_pages,
149 void **kaddr, pfn_t *pfn)
150{
151 resource_size_t offset = pgoff * PAGE_SIZE;
152
153 *kaddr = (void *) bank->io_addr + offset;
154 *pfn = phys_to_pfn_t(bank->ph_addr + offset, PFN_DEV);
155 return (bank->size - offset) / PAGE_SIZE;
156}
157
158static long
159axon_ram_dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, long nr_pages,
160 void **kaddr, pfn_t *pfn)
161{
162 struct axon_ram_bank *bank = dax_get_private(dax_dev);
163
164 return __axon_ram_direct_access(bank, pgoff, nr_pages, kaddr, pfn);
165}
166
167static size_t axon_ram_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff,
168 void *addr, size_t bytes, struct iov_iter *i)
169{
170 return copy_from_iter(addr, bytes, i);
171}
172
173static const struct dax_operations axon_ram_dax_ops = {
174 .direct_access = axon_ram_dax_direct_access,
175 .copy_from_iter = axon_ram_copy_from_iter,
176};
177
178
179
180
181
182static int axon_ram_probe(struct platform_device *device)
183{
184 static int axon_ram_bank_id = -1;
185 struct axon_ram_bank *bank;
186 struct resource resource;
187 int rc = 0;
188
189 axon_ram_bank_id++;
190
191 dev_info(&device->dev, "Found memory controller on %pOF\n",
192 device->dev.of_node);
193
194 bank = kzalloc(sizeof(*bank), GFP_KERNEL);
195 if (!bank)
196 return -ENOMEM;
197
198 device->dev.platform_data = bank;
199
200 bank->device = device;
201
202 if (of_address_to_resource(device->dev.of_node, 0, &resource) != 0) {
203 dev_err(&device->dev, "Cannot access device tree\n");
204 rc = -EFAULT;
205 goto failed;
206 }
207
208 bank->size = resource_size(&resource);
209
210 if (bank->size == 0) {
211 dev_err(&device->dev, "No DDR2 memory found for %s%d\n",
212 AXON_RAM_DEVICE_NAME, axon_ram_bank_id);
213 rc = -ENODEV;
214 goto failed;
215 }
216
217 dev_info(&device->dev, "Register DDR2 memory device %s%d with %luMB\n",
218 AXON_RAM_DEVICE_NAME, axon_ram_bank_id, bank->size >> 20);
219
220 bank->ph_addr = resource.start;
221 bank->io_addr = (unsigned long) ioremap_prot(
222 bank->ph_addr, bank->size, _PAGE_NO_CACHE);
223 if (bank->io_addr == 0) {
224 dev_err(&device->dev, "ioremap() failed\n");
225 rc = -EFAULT;
226 goto failed;
227 }
228
229 bank->disk = alloc_disk(AXON_RAM_MINORS_PER_DISK);
230 if (bank->disk == NULL) {
231 dev_err(&device->dev, "Cannot register disk\n");
232 rc = -EFAULT;
233 goto failed;
234 }
235
236
237 bank->disk->major = azfs_major;
238 bank->disk->first_minor = azfs_minor;
239 bank->disk->fops = &axon_ram_devops;
240 bank->disk->private_data = bank;
241
242 sprintf(bank->disk->disk_name, "%s%d",
243 AXON_RAM_DEVICE_NAME, axon_ram_bank_id);
244
245 bank->dax_dev = alloc_dax(bank, bank->disk->disk_name,
246 &axon_ram_dax_ops);
247 if (!bank->dax_dev) {
248 rc = -ENOMEM;
249 goto failed;
250 }
251
252 bank->disk->queue = blk_alloc_queue(GFP_KERNEL);
253 if (bank->disk->queue == NULL) {
254 dev_err(&device->dev, "Cannot register disk queue\n");
255 rc = -EFAULT;
256 goto failed;
257 }
258
259 set_capacity(bank->disk, bank->size >> AXON_RAM_SECTOR_SHIFT);
260 blk_queue_make_request(bank->disk->queue, axon_ram_make_request);
261 blk_queue_logical_block_size(bank->disk->queue, AXON_RAM_SECTOR_SIZE);
262 device_add_disk(&device->dev, bank->disk);
263
264 bank->irq_id = irq_of_parse_and_map(device->dev.of_node, 0);
265 if (!bank->irq_id) {
266 dev_err(&device->dev, "Cannot access ECC interrupt ID\n");
267 rc = -EFAULT;
268 goto failed;
269 }
270
271 rc = request_irq(bank->irq_id, axon_ram_irq_handler,
272 AXON_RAM_IRQ_FLAGS, bank->disk->disk_name, device);
273 if (rc != 0) {
274 dev_err(&device->dev, "Cannot register ECC interrupt handler\n");
275 bank->irq_id = 0;
276 rc = -EFAULT;
277 goto failed;
278 }
279
280 rc = device_create_file(&device->dev, &dev_attr_ecc);
281 if (rc != 0) {
282 dev_err(&device->dev, "Cannot create sysfs file\n");
283 rc = -EFAULT;
284 goto failed;
285 }
286
287 azfs_minor += bank->disk->minors;
288
289 return 0;
290
291failed:
292 if (bank->irq_id)
293 free_irq(bank->irq_id, device);
294 if (bank->disk != NULL) {
295 if (bank->disk->major > 0)
296 unregister_blkdev(bank->disk->major,
297 bank->disk->disk_name);
298 if (bank->disk->flags & GENHD_FL_UP)
299 del_gendisk(bank->disk);
300 put_disk(bank->disk);
301 }
302 kill_dax(bank->dax_dev);
303 put_dax(bank->dax_dev);
304 device->dev.platform_data = NULL;
305 if (bank->io_addr != 0)
306 iounmap((void __iomem *) bank->io_addr);
307 kfree(bank);
308 return rc;
309}
310
311
312
313
314
315static int
316axon_ram_remove(struct platform_device *device)
317{
318 struct axon_ram_bank *bank = device->dev.platform_data;
319
320 BUG_ON(!bank || !bank->disk);
321
322 device_remove_file(&device->dev, &dev_attr_ecc);
323 free_irq(bank->irq_id, device);
324 kill_dax(bank->dax_dev);
325 put_dax(bank->dax_dev);
326 del_gendisk(bank->disk);
327 put_disk(bank->disk);
328 iounmap((void __iomem *) bank->io_addr);
329 kfree(bank);
330
331 return 0;
332}
333
334static const struct of_device_id axon_ram_device_id[] = {
335 {
336 .type = "dma-memory"
337 },
338 {}
339};
340MODULE_DEVICE_TABLE(of, axon_ram_device_id);
341
342static struct platform_driver axon_ram_driver = {
343 .probe = axon_ram_probe,
344 .remove = axon_ram_remove,
345 .driver = {
346 .name = AXON_RAM_MODULE_NAME,
347 .of_match_table = axon_ram_device_id,
348 },
349};
350
351
352
353
354static int __init
355axon_ram_init(void)
356{
357 azfs_major = register_blkdev(azfs_major, AXON_RAM_DEVICE_NAME);
358 if (azfs_major < 0) {
359 printk(KERN_ERR "%s cannot become block device major number\n",
360 AXON_RAM_MODULE_NAME);
361 return -EFAULT;
362 }
363 azfs_minor = 0;
364
365 return platform_driver_register(&axon_ram_driver);
366}
367
368
369
370
371static void __exit
372axon_ram_exit(void)
373{
374 platform_driver_unregister(&axon_ram_driver);
375 unregister_blkdev(azfs_major, AXON_RAM_DEVICE_NAME);
376}
377
378module_init(axon_ram_init);
379module_exit(axon_ram_exit);
380
381MODULE_LICENSE("GPL");
382MODULE_AUTHOR("Maxim Shchetynin <maxim@de.ibm.com>");
383MODULE_DESCRIPTION("Axon DDR2 RAM device driver for IBM Cell BE");
384
