Version:  2.0.40 2.2.26 2.4.37 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2 4.3 4.4

Linux/arch/powerpc/sysdev/axonram.c

  1 /*
  2  * (C) Copyright IBM Deutschland Entwicklung GmbH 2006
  3  *
  4  * Author: Maxim Shchetynin <maxim@de.ibm.com>
  5  *
  6  * Axon DDR2 device driver.
  7  * It registers one block device per Axon's DDR2 memory bank found on a system.
  8  * Block devices are called axonram?, their major and minor numbers are
  9  * available in /proc/devices, /proc/partitions or in /sys/block/axonram?/dev.
 10  *
 11  * This program is free software; you can redistribute it and/or modify
 12  * it under the terms of the GNU General Public License as published by
 13  * the Free Software Foundation; either version 2, or (at your option)
 14  * any later version.
 15  *
 16  * This program is distributed in the hope that it will be useful,
 17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
 18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 19  * GNU General Public License for more details.
 20  *
 21  * You should have received a copy of the GNU General Public License
 22  * along with this program; if not, write to the Free Software
 23  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 24  */
 25 
 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 
 59 static int azfs_major, azfs_minor;
 60 
 61 struct 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 
 71 static ssize_t
 72 axon_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 
 82 static DEVICE_ATTR(ecc, S_IRUGO, axon_ram_sysfs_ecc, NULL);
 83 
 84 /**
 85  * axon_ram_irq_handler - interrupt handler for Axon RAM ECC
 86  * @irq: interrupt ID
 87  * @dev: pointer to of_device
 88  */
 89 static irqreturn_t
 90 axon_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  * axon_ram_make_request - make_request() method for block device
104  * @queue, @bio: see blk_queue_make_request()
105  */
106 static blk_qc_t
107 axon_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  * axon_ram_direct_access - direct_access() method for block device
141  * @device, @sector, @data: see block_device_operations method
142  */
143 static long
144 axon_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 
157 static const struct block_device_operations axon_ram_devops = {
158         .owner          = THIS_MODULE,
159         .direct_access  = axon_ram_direct_access
160 };
161 
162 /**
163  * axon_ram_probe - probe() method for platform driver
164  * @device: see platform_driver method
165  */
166 static 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 
271 failed:
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  * axon_ram_remove - remove() method for platform driver
292  * @device: see of_platform_driver method
293  */
294 static int
295 axon_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 
310 static const struct of_device_id axon_ram_device_id[] = {
311         {
312                 .type   = "dma-memory"
313         },
314         {}
315 };
316 
317 static 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  * axon_ram_init
328  */
329 static int __init
330 axon_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  * axon_ram_exit
345  */
346 static void __exit
347 axon_ram_exit(void)
348 {
349         platform_driver_unregister(&axon_ram_driver);
350         unregister_blkdev(azfs_major, AXON_RAM_DEVICE_NAME);
351 }
352 
353 module_init(axon_ram_init);
354 module_exit(axon_ram_exit);
355 
356 MODULE_LICENSE("GPL");
357 MODULE_AUTHOR("Maxim Shchetynin <maxim@de.ibm.com>");
358 MODULE_DESCRIPTION("Axon DDR2 RAM device driver for IBM Cell BE");
359 

This page was automatically generated by LXR 0.3.1 (source).  •  Linux is a registered trademark of Linus Torvalds  •  Contact us