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 int 143axon_ram_direct_access(struct block_device *device, sector_t sector, 144 void **kaddr, unsigned long *pfn) 145{ 146 struct axon_ram_bank *bank = device->bd_disk->private_data; 147 loff_t offset; 148 149 offset = sector; 150 if (device->bd_part != NULL) 151 offset += device->bd_part->start_sect; 152 offset <<= AXON_RAM_SECTOR_SHIFT; 153 if (offset >= bank->size) { 154 dev_err(&bank->device->dev, "Access outside of address space\n"); 155 return -ERANGE; 156 } 157 158 *kaddr = (void *)(bank->ph_addr + offset); 159 *pfn = virt_to_phys(kaddr) >> PAGE_SHIFT; 160 161 return 0; 162} 163 164static const struct block_device_operations axon_ram_devops = { 165 .owner = THIS_MODULE, 166 .direct_access = axon_ram_direct_access 167}; 168 169/** 170 * axon_ram_probe - probe() method for platform driver 171 * @device: see platform_driver method 172 */ 173static int axon_ram_probe(struct platform_device *device) 174{ 175 static int axon_ram_bank_id = -1; 176 struct axon_ram_bank *bank; 177 struct resource resource; 178 int rc = 0; 179 180 axon_ram_bank_id++; 181 182 dev_info(&device->dev, "Found memory controller on %s\n", 183 device->dev.of_node->full_name); 184 185 bank = kzalloc(sizeof(struct axon_ram_bank), GFP_KERNEL); 186 if (bank == NULL) { 187 dev_err(&device->dev, "Out of memory\n"); 188 rc = -ENOMEM; 189 goto failed; 190 } 191 192 device->dev.platform_data = bank; 193 194 bank->device = device; 195 196 if (of_address_to_resource(device->dev.of_node, 0, &resource) != 0) { 197 dev_err(&device->dev, "Cannot access device tree\n"); 198 rc = -EFAULT; 199 goto failed; 200 } 201 202 bank->size = resource_size(&resource); 203 204 if (bank->size == 0) { 205 dev_err(&device->dev, "No DDR2 memory found for %s%d\n", 206 AXON_RAM_DEVICE_NAME, axon_ram_bank_id); 207 rc = -ENODEV; 208 goto failed; 209 } 210 211 dev_info(&device->dev, "Register DDR2 memory device %s%d with %luMB\n", 212 AXON_RAM_DEVICE_NAME, axon_ram_bank_id, bank->size >> 20); 213 214 bank->ph_addr = resource.start; 215 bank->io_addr = (unsigned long) ioremap_prot( 216 bank->ph_addr, bank->size, _PAGE_NO_CACHE); 217 if (bank->io_addr == 0) { 218 dev_err(&device->dev, "ioremap() failed\n"); 219 rc = -EFAULT; 220 goto failed; 221 } 222 223 bank->disk = alloc_disk(AXON_RAM_MINORS_PER_DISK); 224 if (bank->disk == NULL) { 225 dev_err(&device->dev, "Cannot register disk\n"); 226 rc = -EFAULT; 227 goto failed; 228 } 229 230 bank->disk->major = azfs_major; 231 bank->disk->first_minor = azfs_minor; 232 bank->disk->fops = &axon_ram_devops; 233 bank->disk->private_data = bank; 234 bank->disk->driverfs_dev = &device->dev; 235 236 sprintf(bank->disk->disk_name, "%s%d", 237 AXON_RAM_DEVICE_NAME, axon_ram_bank_id); 238 239 bank->disk->queue = blk_alloc_queue(GFP_KERNEL); 240 if (bank->disk->queue == NULL) { 241 dev_err(&device->dev, "Cannot register disk queue\n"); 242 rc = -EFAULT; 243 goto failed; 244 } 245 246 set_capacity(bank->disk, bank->size >> AXON_RAM_SECTOR_SHIFT); 247 blk_queue_make_request(bank->disk->queue, axon_ram_make_request); 248 blk_queue_logical_block_size(bank->disk->queue, AXON_RAM_SECTOR_SIZE); 249 add_disk(bank->disk); 250 251 bank->irq_id = irq_of_parse_and_map(device->dev.of_node, 0); 252 if (bank->irq_id == NO_IRQ) { 253 dev_err(&device->dev, "Cannot access ECC interrupt ID\n"); 254 rc = -EFAULT; 255 goto failed; 256 } 257 258 rc = request_irq(bank->irq_id, axon_ram_irq_handler, 259 AXON_RAM_IRQ_FLAGS, bank->disk->disk_name, device); 260 if (rc != 0) { 261 dev_err(&device->dev, "Cannot register ECC interrupt handler\n"); 262 bank->irq_id = NO_IRQ; 263 rc = -EFAULT; 264 goto failed; 265 } 266 267 rc = device_create_file(&device->dev, &dev_attr_ecc); 268 if (rc != 0) { 269 dev_err(&device->dev, "Cannot create sysfs file\n"); 270 rc = -EFAULT; 271 goto failed; 272 } 273 274 azfs_minor += bank->disk->minors; 275 276 return 0; 277 278failed: 279 if (bank != NULL) { 280 if (bank->irq_id != NO_IRQ) 281 free_irq(bank->irq_id, device); 282 if (bank->disk != NULL) { 283 if (bank->disk->major > 0) 284 unregister_blkdev(bank->disk->major, 285 bank->disk->disk_name); 286 del_gendisk(bank->disk); 287 } 288 device->dev.platform_data = NULL; 289 if (bank->io_addr != 0) 290 iounmap((void __iomem *) bank->io_addr); 291 kfree(bank); 292 } 293 294 return rc; 295} 296 297/** 298 * axon_ram_remove - remove() method for platform driver 299 * @device: see of_platform_driver method 300 */ 301static int 302axon_ram_remove(struct platform_device *device) 303{ 304 struct axon_ram_bank *bank = device->dev.platform_data; 305 306 BUG_ON(!bank || !bank->disk); 307 308 device_remove_file(&device->dev, &dev_attr_ecc); 309 free_irq(bank->irq_id, device); 310 del_gendisk(bank->disk); 311 iounmap((void __iomem *) bank->io_addr); 312 kfree(bank); 313 314 return 0; 315} 316 317static const struct of_device_id axon_ram_device_id[] = { 318 { 319 .type = "dma-memory" 320 }, 321 {} 322}; 323 324static struct platform_driver axon_ram_driver = { 325 .probe = axon_ram_probe, 326 .remove = axon_ram_remove, 327 .driver = { 328 .name = AXON_RAM_MODULE_NAME, 329 .owner = THIS_MODULE, 330 .of_match_table = axon_ram_device_id, 331 }, 332}; 333 334/** 335 * axon_ram_init 336 */ 337static int __init 338axon_ram_init(void) 339{ 340 azfs_major = register_blkdev(azfs_major, AXON_RAM_DEVICE_NAME); 341 if (azfs_major < 0) { 342 printk(KERN_ERR "%s cannot become block device major number\n", 343 AXON_RAM_MODULE_NAME); 344 return -EFAULT; 345 } 346 azfs_minor = 0; 347 348 return platform_driver_register(&axon_ram_driver); 349} 350 351/** 352 * axon_ram_exit 353 */ 354static void __exit 355axon_ram_exit(void) 356{ 357 platform_driver_unregister(&axon_ram_driver); 358 unregister_blkdev(azfs_major, AXON_RAM_DEVICE_NAME); 359} 360 361module_init(axon_ram_init); 362module_exit(axon_ram_exit); 363 364MODULE_LICENSE("GPL"); 365MODULE_AUTHOR("Maxim Shchetynin <maxim@de.ibm.com>"); 366MODULE_DESCRIPTION("Axon DDR2 RAM device driver for IBM Cell BE"); 367