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 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 * axon_ram_irq_handler - interrupt handler for Axon RAM ECC 86 * @irq: interrupt ID 87 * @dev: pointer to of_device 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 * axon_ram_make_request - make_request() method for block device 104 * @queue, @bio: see blk_queue_make_request() 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 * axon_ram_direct_access - direct_access() method for block device 140 * @device, @sector, @data: see block_device_operations method 141 */ 142static long 143axon_ram_direct_access(struct block_device *device, sector_t sector, 144 void **kaddr, unsigned long *pfn, long size) 145{ 146 struct axon_ram_bank *bank = device->bd_disk->private_data; 147 loff_t offset = (loff_t)sector << AXON_RAM_SECTOR_SHIFT; 148 149 *kaddr = (void *)(bank->ph_addr + offset); 150 *pfn = virt_to_phys(*kaddr) >> PAGE_SHIFT; 151 152 return bank->size - offset; 153} 154 155static const struct block_device_operations axon_ram_devops = { 156 .owner = THIS_MODULE, 157 .direct_access = axon_ram_direct_access 158}; 159 160/** 161 * axon_ram_probe - probe() method for platform driver 162 * @device: see platform_driver method 163 */ 164static int axon_ram_probe(struct platform_device *device) 165{ 166 static int axon_ram_bank_id = -1; 167 struct axon_ram_bank *bank; 168 struct resource resource; 169 int rc = 0; 170 171 axon_ram_bank_id++; 172 173 dev_info(&device->dev, "Found memory controller on %s\n", 174 device->dev.of_node->full_name); 175 176 bank = kzalloc(sizeof(struct axon_ram_bank), GFP_KERNEL); 177 if (bank == NULL) { 178 dev_err(&device->dev, "Out of memory\n"); 179 rc = -ENOMEM; 180 goto failed; 181 } 182 183 device->dev.platform_data = bank; 184 185 bank->device = device; 186 187 if (of_address_to_resource(device->dev.of_node, 0, &resource) != 0) { 188 dev_err(&device->dev, "Cannot access device tree\n"); 189 rc = -EFAULT; 190 goto failed; 191 } 192 193 bank->size = resource_size(&resource); 194 195 if (bank->size == 0) { 196 dev_err(&device->dev, "No DDR2 memory found for %s%d\n", 197 AXON_RAM_DEVICE_NAME, axon_ram_bank_id); 198 rc = -ENODEV; 199 goto failed; 200 } 201 202 dev_info(&device->dev, "Register DDR2 memory device %s%d with %luMB\n", 203 AXON_RAM_DEVICE_NAME, axon_ram_bank_id, bank->size >> 20); 204 205 bank->ph_addr = resource.start; 206 bank->io_addr = (unsigned long) ioremap_prot( 207 bank->ph_addr, bank->size, _PAGE_NO_CACHE); 208 if (bank->io_addr == 0) { 209 dev_err(&device->dev, "ioremap() failed\n"); 210 rc = -EFAULT; 211 goto failed; 212 } 213 214 bank->disk = alloc_disk(AXON_RAM_MINORS_PER_DISK); 215 if (bank->disk == NULL) { 216 dev_err(&device->dev, "Cannot register disk\n"); 217 rc = -EFAULT; 218 goto failed; 219 } 220 221 bank->disk->major = azfs_major; 222 bank->disk->first_minor = azfs_minor; 223 bank->disk->fops = &axon_ram_devops; 224 bank->disk->private_data = bank; 225 bank->disk->driverfs_dev = &device->dev; 226 227 sprintf(bank->disk->disk_name, "%s%d", 228 AXON_RAM_DEVICE_NAME, axon_ram_bank_id); 229 230 bank->disk->queue = blk_alloc_queue(GFP_KERNEL); 231 if (bank->disk->queue == NULL) { 232 dev_err(&device->dev, "Cannot register disk queue\n"); 233 rc = -EFAULT; 234 goto failed; 235 } 236 237 set_capacity(bank->disk, bank->size >> AXON_RAM_SECTOR_SHIFT); 238 blk_queue_make_request(bank->disk->queue, axon_ram_make_request); 239 blk_queue_logical_block_size(bank->disk->queue, AXON_RAM_SECTOR_SIZE); 240 add_disk(bank->disk); 241 242 bank->irq_id = irq_of_parse_and_map(device->dev.of_node, 0); 243 if (bank->irq_id == NO_IRQ) { 244 dev_err(&device->dev, "Cannot access ECC interrupt ID\n"); 245 rc = -EFAULT; 246 goto failed; 247 } 248 249 rc = request_irq(bank->irq_id, axon_ram_irq_handler, 250 AXON_RAM_IRQ_FLAGS, bank->disk->disk_name, device); 251 if (rc != 0) { 252 dev_err(&device->dev, "Cannot register ECC interrupt handler\n"); 253 bank->irq_id = NO_IRQ; 254 rc = -EFAULT; 255 goto failed; 256 } 257 258 rc = device_create_file(&device->dev, &dev_attr_ecc); 259 if (rc != 0) { 260 dev_err(&device->dev, "Cannot create sysfs file\n"); 261 rc = -EFAULT; 262 goto failed; 263 } 264 265 azfs_minor += bank->disk->minors; 266 267 return 0; 268 269failed: 270 if (bank != NULL) { 271 if (bank->irq_id != NO_IRQ) 272 free_irq(bank->irq_id, device); 273 if (bank->disk != NULL) { 274 if (bank->disk->major > 0) 275 unregister_blkdev(bank->disk->major, 276 bank->disk->disk_name); 277 del_gendisk(bank->disk); 278 } 279 device->dev.platform_data = NULL; 280 if (bank->io_addr != 0) 281 iounmap((void __iomem *) bank->io_addr); 282 kfree(bank); 283 } 284 285 return rc; 286} 287 288/** 289 * axon_ram_remove - remove() method for platform driver 290 * @device: see of_platform_driver method 291 */ 292static int 293axon_ram_remove(struct platform_device *device) 294{ 295 struct axon_ram_bank *bank = device->dev.platform_data; 296 297 BUG_ON(!bank || !bank->disk); 298 299 device_remove_file(&device->dev, &dev_attr_ecc); 300 free_irq(bank->irq_id, device); 301 del_gendisk(bank->disk); 302 iounmap((void __iomem *) bank->io_addr); 303 kfree(bank); 304 305 return 0; 306} 307 308static const struct of_device_id axon_ram_device_id[] = { 309 { 310 .type = "dma-memory" 311 }, 312 {} 313}; 314 315static struct platform_driver axon_ram_driver = { 316 .probe = axon_ram_probe, 317 .remove = axon_ram_remove, 318 .driver = { 319 .name = AXON_RAM_MODULE_NAME, 320 .of_match_table = axon_ram_device_id, 321 }, 322}; 323 324/** 325 * axon_ram_init 326 */ 327static int __init 328axon_ram_init(void) 329{ 330 azfs_major = register_blkdev(azfs_major, AXON_RAM_DEVICE_NAME); 331 if (azfs_major < 0) { 332 printk(KERN_ERR "%s cannot become block device major number\n", 333 AXON_RAM_MODULE_NAME); 334 return -EFAULT; 335 } 336 azfs_minor = 0; 337 338 return platform_driver_register(&axon_ram_driver); 339} 340 341/** 342 * axon_ram_exit 343 */ 344static void __exit 345axon_ram_exit(void) 346{ 347 platform_driver_unregister(&axon_ram_driver); 348 unregister_blkdev(azfs_major, AXON_RAM_DEVICE_NAME); 349} 350 351module_init(axon_ram_init); 352module_exit(axon_ram_exit); 353 354MODULE_LICENSE("GPL"); 355MODULE_AUTHOR("Maxim Shchetynin <maxim@de.ibm.com>"); 356MODULE_DESCRIPTION("Axon DDR2 RAM device driver for IBM Cell BE"); 357