2 * (C) Copyright IBM Deutschland Entwicklung GmbH 2006
4 * Author: Maxim Shchetynin <maxim@de.ibm.com>
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.
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)
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.
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.
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>
32 #include <linux/genhd.h>
33 #include <linux/interrupt.h>
35 #include <linux/ioport.h>
36 #include <linux/irq.h>
37 #include <linux/irqreturn.h>
38 #include <linux/kernel.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>
52 #define AXON_RAM_MODULE_NAME "axonram"
53 #define AXON_RAM_DEVICE_NAME "axonram"
54 #define AXON_RAM_MINORS_PER_DISK 16
55 #define AXON_RAM_BLOCK_SHIFT PAGE_SHIFT
56 #define AXON_RAM_BLOCK_SIZE 1 << AXON_RAM_BLOCK_SHIFT
57 #define AXON_RAM_SECTOR_SHIFT 9
58 #define AXON_RAM_SECTOR_SIZE 1 << AXON_RAM_SECTOR_SHIFT
59 #define AXON_RAM_IRQ_FLAGS IRQF_SHARED | IRQF_TRIGGER_RISING
61 static int azfs_major, azfs_minor;
63 struct axon_ram_bank {
64 struct platform_device *device;
66 struct dax_device *dax_dev;
68 unsigned long ph_addr;
69 unsigned long io_addr;
71 unsigned long ecc_counter;
75 axon_ram_sysfs_ecc(struct device *dev, struct device_attribute *attr, char *buf)
77 struct platform_device *device = to_platform_device(dev);
78 struct axon_ram_bank *bank = device->dev.platform_data;
82 return sprintf(buf, "%ld\n", bank->ecc_counter);
85 static DEVICE_ATTR(ecc, S_IRUGO, axon_ram_sysfs_ecc, NULL);
88 * axon_ram_irq_handler - interrupt handler for Axon RAM ECC
90 * @dev: pointer to of_device
93 axon_ram_irq_handler(int irq, void *dev)
95 struct platform_device *device = dev;
96 struct axon_ram_bank *bank = device->dev.platform_data;
100 dev_err(&device->dev, "Correctable memory error occurred\n");
106 * axon_ram_make_request - make_request() method for block device
107 * @queue, @bio: see blk_queue_make_request()
110 axon_ram_make_request(struct request_queue *queue, struct bio *bio)
112 struct axon_ram_bank *bank = bio->bi_bdev->bd_disk->private_data;
113 unsigned long phys_mem, phys_end;
116 unsigned int transfered;
117 struct bvec_iter iter;
119 phys_mem = bank->io_addr + (bio->bi_iter.bi_sector <<
120 AXON_RAM_SECTOR_SHIFT);
121 phys_end = bank->io_addr + bank->size;
123 bio_for_each_segment(vec, bio, iter) {
124 if (unlikely(phys_mem + vec.bv_len > phys_end)) {
126 return BLK_QC_T_NONE;
129 user_mem = page_address(vec.bv_page) + vec.bv_offset;
130 if (bio_data_dir(bio) == READ)
131 memcpy(user_mem, (void *) phys_mem, vec.bv_len);
133 memcpy((void *) phys_mem, user_mem, vec.bv_len);
135 phys_mem += vec.bv_len;
136 transfered += vec.bv_len;
139 return BLK_QC_T_NONE;
142 static const struct block_device_operations axon_ram_devops = {
143 .owner = THIS_MODULE,
147 __axon_ram_direct_access(struct axon_ram_bank *bank, pgoff_t pgoff, long nr_pages,
148 void **kaddr, pfn_t *pfn)
150 resource_size_t offset = pgoff * PAGE_SIZE;
152 *kaddr = (void *) bank->io_addr + offset;
153 *pfn = phys_to_pfn_t(bank->ph_addr + offset, PFN_DEV);
154 return (bank->size - offset) / PAGE_SIZE;
158 axon_ram_dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, long nr_pages,
159 void **kaddr, pfn_t *pfn)
161 struct axon_ram_bank *bank = dax_get_private(dax_dev);
163 return __axon_ram_direct_access(bank, pgoff, nr_pages, kaddr, pfn);
166 static const struct dax_operations axon_ram_dax_ops = {
167 .direct_access = axon_ram_dax_direct_access,
171 * axon_ram_probe - probe() method for platform driver
172 * @device: see platform_driver method
174 static int axon_ram_probe(struct platform_device *device)
176 static int axon_ram_bank_id = -1;
177 struct axon_ram_bank *bank;
178 struct resource resource;
183 dev_info(&device->dev, "Found memory controller on %s\n",
184 device->dev.of_node->full_name);
186 bank = kzalloc(sizeof(struct axon_ram_bank), GFP_KERNEL);
188 dev_err(&device->dev, "Out of memory\n");
193 device->dev.platform_data = bank;
195 bank->device = device;
197 if (of_address_to_resource(device->dev.of_node, 0, &resource) != 0) {
198 dev_err(&device->dev, "Cannot access device tree\n");
203 bank->size = resource_size(&resource);
205 if (bank->size == 0) {
206 dev_err(&device->dev, "No DDR2 memory found for %s%d\n",
207 AXON_RAM_DEVICE_NAME, axon_ram_bank_id);
212 dev_info(&device->dev, "Register DDR2 memory device %s%d with %luMB\n",
213 AXON_RAM_DEVICE_NAME, axon_ram_bank_id, bank->size >> 20);
215 bank->ph_addr = resource.start;
216 bank->io_addr = (unsigned long) ioremap_prot(
217 bank->ph_addr, bank->size, _PAGE_NO_CACHE);
218 if (bank->io_addr == 0) {
219 dev_err(&device->dev, "ioremap() failed\n");
224 bank->disk = alloc_disk(AXON_RAM_MINORS_PER_DISK);
225 if (bank->disk == NULL) {
226 dev_err(&device->dev, "Cannot register disk\n");
232 bank->disk->major = azfs_major;
233 bank->disk->first_minor = azfs_minor;
234 bank->disk->fops = &axon_ram_devops;
235 bank->disk->private_data = bank;
237 sprintf(bank->disk->disk_name, "%s%d",
238 AXON_RAM_DEVICE_NAME, axon_ram_bank_id);
240 bank->dax_dev = alloc_dax(bank, bank->disk->disk_name,
242 if (!bank->dax_dev) {
247 bank->disk->queue = blk_alloc_queue(GFP_KERNEL);
248 if (bank->disk->queue == NULL) {
249 dev_err(&device->dev, "Cannot register disk queue\n");
254 set_capacity(bank->disk, bank->size >> AXON_RAM_SECTOR_SHIFT);
255 blk_queue_make_request(bank->disk->queue, axon_ram_make_request);
256 blk_queue_logical_block_size(bank->disk->queue, AXON_RAM_SECTOR_SIZE);
257 device_add_disk(&device->dev, bank->disk);
259 bank->irq_id = irq_of_parse_and_map(device->dev.of_node, 0);
261 dev_err(&device->dev, "Cannot access ECC interrupt ID\n");
266 rc = request_irq(bank->irq_id, axon_ram_irq_handler,
267 AXON_RAM_IRQ_FLAGS, bank->disk->disk_name, device);
269 dev_err(&device->dev, "Cannot register ECC interrupt handler\n");
275 rc = device_create_file(&device->dev, &dev_attr_ecc);
277 dev_err(&device->dev, "Cannot create sysfs file\n");
282 azfs_minor += bank->disk->minors;
289 free_irq(bank->irq_id, device);
290 if (bank->disk != NULL) {
291 if (bank->disk->major > 0)
292 unregister_blkdev(bank->disk->major,
293 bank->disk->disk_name);
294 if (bank->disk->flags & GENHD_FL_UP)
295 del_gendisk(bank->disk);
296 put_disk(bank->disk);
298 kill_dax(bank->dax_dev);
299 put_dax(bank->dax_dev);
300 device->dev.platform_data = NULL;
301 if (bank->io_addr != 0)
302 iounmap((void __iomem *) bank->io_addr);
310 * axon_ram_remove - remove() method for platform driver
311 * @device: see of_platform_driver method
314 axon_ram_remove(struct platform_device *device)
316 struct axon_ram_bank *bank = device->dev.platform_data;
318 BUG_ON(!bank || !bank->disk);
320 device_remove_file(&device->dev, &dev_attr_ecc);
321 free_irq(bank->irq_id, device);
322 kill_dax(bank->dax_dev);
323 put_dax(bank->dax_dev);
324 del_gendisk(bank->disk);
325 put_disk(bank->disk);
326 iounmap((void __iomem *) bank->io_addr);
332 static const struct of_device_id axon_ram_device_id[] = {
338 MODULE_DEVICE_TABLE(of, axon_ram_device_id);
340 static struct platform_driver axon_ram_driver = {
341 .probe = axon_ram_probe,
342 .remove = axon_ram_remove,
344 .name = AXON_RAM_MODULE_NAME,
345 .of_match_table = axon_ram_device_id,
355 azfs_major = register_blkdev(azfs_major, AXON_RAM_DEVICE_NAME);
356 if (azfs_major < 0) {
357 printk(KERN_ERR "%s cannot become block device major number\n",
358 AXON_RAM_MODULE_NAME);
363 return platform_driver_register(&axon_ram_driver);
372 platform_driver_unregister(&axon_ram_driver);
373 unregister_blkdev(azfs_major, AXON_RAM_DEVICE_NAME);
376 module_init(axon_ram_init);
377 module_exit(axon_ram_exit);
379 MODULE_LICENSE("GPL");
380 MODULE_AUTHOR("Maxim Shchetynin <maxim@de.ibm.com>");
381 MODULE_DESCRIPTION("Axon DDR2 RAM device driver for IBM Cell BE");