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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 blk_qc_t
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 BLK_QC_T_NONE;
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);
136 return BLK_QC_T_NONE;
137}
138
139
140
141
142
143static long
144axon_ram_direct_access(struct block_device *device, sector_t sector,
145 void __pmem **kaddr, unsigned long *pfn)
146{
147 struct axon_ram_bank *bank = device->bd_disk->private_data;
148 loff_t offset = (loff_t)sector << AXON_RAM_SECTOR_SHIFT;
149 void *addr = (void *)(bank->ph_addr + offset);
150
151 *kaddr = (void __pmem *)addr;
152 *pfn = virt_to_phys(addr) >> PAGE_SHIFT;
153
154 return bank->size - offset;
155}
156
157static const struct block_device_operations axon_ram_devops = {
158 .owner = THIS_MODULE,
159 .direct_access = axon_ram_direct_access
160};
161
162
163
164
165
166static int axon_ram_probe(struct platform_device *device)
167{
168 static int axon_ram_bank_id = -1;
169 struct axon_ram_bank *bank;
170 struct resource resource;
171 int rc = 0;
172
173 axon_ram_bank_id++;
174
175 dev_info(&device->dev, "Found memory controller on %s\n",
176 device->dev.of_node->full_name);
177
178 bank = kzalloc(sizeof(struct axon_ram_bank), GFP_KERNEL);
179 if (bank == NULL) {
180 dev_err(&device->dev, "Out of memory\n");
181 rc = -ENOMEM;
182 goto failed;
183 }
184
185 device->dev.platform_data = bank;
186
187 bank->device = device;
188
189 if (of_address_to_resource(device->dev.of_node, 0, &resource) != 0) {
190 dev_err(&device->dev, "Cannot access device tree\n");
191 rc = -EFAULT;
192 goto failed;
193 }
194
195 bank->size = resource_size(&resource);
196
197 if (bank->size == 0) {
198 dev_err(&device->dev, "No DDR2 memory found for %s%d\n",
199 AXON_RAM_DEVICE_NAME, axon_ram_bank_id);
200 rc = -ENODEV;
201 goto failed;
202 }
203
204 dev_info(&device->dev, "Register DDR2 memory device %s%d with %luMB\n",
205 AXON_RAM_DEVICE_NAME, axon_ram_bank_id, bank->size >> 20);
206
207 bank->ph_addr = resource.start;
208 bank->io_addr = (unsigned long) ioremap_prot(
209 bank->ph_addr, bank->size, _PAGE_NO_CACHE);
210 if (bank->io_addr == 0) {
211 dev_err(&device->dev, "ioremap() failed\n");
212 rc = -EFAULT;
213 goto failed;
214 }
215
216 bank->disk = alloc_disk(AXON_RAM_MINORS_PER_DISK);
217 if (bank->disk == NULL) {
218 dev_err(&device->dev, "Cannot register disk\n");
219 rc = -EFAULT;
220 goto failed;
221 }
222
223 bank->disk->major = azfs_major;
224 bank->disk->first_minor = azfs_minor;
225 bank->disk->fops = &axon_ram_devops;
226 bank->disk->private_data = bank;
227 bank->disk->driverfs_dev = &device->dev;
228
229 sprintf(bank->disk->disk_name, "%s%d",
230 AXON_RAM_DEVICE_NAME, axon_ram_bank_id);
231
232 bank->disk->queue = blk_alloc_queue(GFP_KERNEL);
233 if (bank->disk->queue == NULL) {
234 dev_err(&device->dev, "Cannot register disk queue\n");
235 rc = -EFAULT;
236 goto failed;
237 }
238
239 set_capacity(bank->disk, bank->size >> AXON_RAM_SECTOR_SHIFT);
240 blk_queue_make_request(bank->disk->queue, axon_ram_make_request);
241 blk_queue_logical_block_size(bank->disk->queue, AXON_RAM_SECTOR_SIZE);
242 add_disk(bank->disk);
243
244 bank->irq_id = irq_of_parse_and_map(device->dev.of_node, 0);
245 if (bank->irq_id == NO_IRQ) {
246 dev_err(&device->dev, "Cannot access ECC interrupt ID\n");
247 rc = -EFAULT;
248 goto failed;
249 }
250
251 rc = request_irq(bank->irq_id, axon_ram_irq_handler,
252 AXON_RAM_IRQ_FLAGS, bank->disk->disk_name, device);
253 if (rc != 0) {
254 dev_err(&device->dev, "Cannot register ECC interrupt handler\n");
255 bank->irq_id = NO_IRQ;
256 rc = -EFAULT;
257 goto failed;
258 }
259
260 rc = device_create_file(&device->dev, &dev_attr_ecc);
261 if (rc != 0) {
262 dev_err(&device->dev, "Cannot create sysfs file\n");
263 rc = -EFAULT;
264 goto failed;
265 }
266
267 azfs_minor += bank->disk->minors;
268
269 return 0;
270
271failed:
272 if (bank != NULL) {
273 if (bank->irq_id != NO_IRQ)
274 free_irq(bank->irq_id, device);
275 if (bank->disk != NULL) {
276 if (bank->disk->major > 0)
277 unregister_blkdev(bank->disk->major,
278 bank->disk->disk_name);
279 del_gendisk(bank->disk);
280 }
281 device->dev.platform_data = NULL;
282 if (bank->io_addr != 0)
283 iounmap((void __iomem *) bank->io_addr);
284 kfree(bank);
285 }
286
287 return rc;
288}
289
290
291
292
293
294static int
295axon_ram_remove(struct platform_device *device)
296{
297 struct axon_ram_bank *bank = device->dev.platform_data;
298
299 BUG_ON(!bank || !bank->disk);
300
301 device_remove_file(&device->dev, &dev_attr_ecc);
302 free_irq(bank->irq_id, device);
303 del_gendisk(bank->disk);
304 iounmap((void __iomem *) bank->io_addr);
305 kfree(bank);
306
307 return 0;
308}
309
310static const struct of_device_id axon_ram_device_id[] = {
311 {
312 .type = "dma-memory"
313 },
314 {}
315};
316
317static struct platform_driver axon_ram_driver = {
318 .probe = axon_ram_probe,
319 .remove = axon_ram_remove,
320 .driver = {
321 .name = AXON_RAM_MODULE_NAME,
322 .of_match_table = axon_ram_device_id,
323 },
324};
325
326
327
328
329static int __init
330axon_ram_init(void)
331{
332 azfs_major = register_blkdev(azfs_major, AXON_RAM_DEVICE_NAME);
333 if (azfs_major < 0) {
334 printk(KERN_ERR "%s cannot become block device major number\n",
335 AXON_RAM_MODULE_NAME);
336 return -EFAULT;
337 }
338 azfs_minor = 0;
339
340 return platform_driver_register(&axon_ram_driver);
341}
342
343
344
345
346static void __exit
347axon_ram_exit(void)
348{
349 platform_driver_unregister(&axon_ram_driver);
350 unregister_blkdev(azfs_major, AXON_RAM_DEVICE_NAME);
351}
352
353module_init(axon_ram_init);
354module_exit(axon_ram_exit);
355
356MODULE_LICENSE("GPL");
357MODULE_AUTHOR("Maxim Shchetynin <maxim@de.ibm.com>");
358MODULE_DESCRIPTION("Axon DDR2 RAM device driver for IBM Cell BE");
359
