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/buffer_head.h>
  29 #include <linux/device.h>
  30 #include <linux/errno.h>
  31 #include <linux/fs.h>
  32 #include <linux/genhd.h>
  33 #include <linux/interrupt.h>
  34 #include <linux/io.h>
  35 #include <linux/ioport.h>
  36 #include <linux/irq.h>
  37 #include <linux/irqreturn.h>
  38 #include <linux/kernel.h>
  39 #include <linux/mm.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 <asm/of_device.h>
  46 #include <asm/of_platform.h>
  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 struct axon_ram_bank {
  60         struct of_device        *device;
  61         struct gendisk          *disk;
  62         unsigned int            irq_correctable;
  63         unsigned int            irq_uncorrectable;
  64         unsigned long           ph_addr;
  65         unsigned long           io_addr;
  66         unsigned long           size;
  67         unsigned long           ecc_counter;
  68 };
  69
  70 static ssize_t
  71 axon_ram_sysfs_ecc(struct device *dev, struct device_attribute *attr, char *buf)
  72 {
  73         struct of_device *device = to_of_device(dev);
  74         struct axon_ram_bank *bank = device->dev.platform_data;
  75
  76         BUG_ON(!bank);
  77
  78         return sprintf(buf, "%ld\n", bank->ecc_counter);
  79 }
  80
  81 static DEVICE_ATTR(ecc, S_IRUGO, axon_ram_sysfs_ecc, NULL);
  82
  83 /**
  84  * axon_ram_irq_handler - interrupt handler for Axon RAM ECC
  85  * @irq: interrupt ID
  86  * @dev: pointer to of_device
  87  */
  88 static irqreturn_t
  89 axon_ram_irq_handler(int irq, void *dev)
  90 {
  91         struct of_device *device = dev;
  92         struct axon_ram_bank *bank = device->dev.platform_data;
  93
  94         BUG_ON(!bank);
  95
  96         if (irq == bank->irq_correctable) {
  97                 dev_err(&device->dev, "Correctable memory error occured\n");
  98                 bank->ecc_counter++;
  99                 return IRQ_HANDLED;
 100         } else if (irq == bank->irq_uncorrectable) {
 101                 dev_err(&device->dev, "Uncorrectable memory error occured\n");
 102                 panic("Critical ECC error on %s", device->node->full_name);
 103         }
 104
 105         return IRQ_NONE;
 106 }
 107
 108 /**
 109  * axon_ram_make_request - make_request() method for block device
 110  * @queue, @bio: see blk_queue_make_request()
 111  */
 112 static int
 113 axon_ram_make_request(struct request_queue *queue, struct bio *bio)
 114 {
 115         struct axon_ram_bank *bank = bio->bi_bdev->bd_disk->private_data;
 116         unsigned long phys_mem, phys_end;
 117         void *user_mem;
 118         struct bio_vec *vec;
 119         unsigned int transfered;
 120         unsigned short idx;
 121         int rc = 0;
 122
 123         phys_mem = bank->io_addr + (bio->bi_sector << AXON_RAM_SECTOR_SHIFT);
 124         phys_end = bank->io_addr + bank->size;
 125         transfered = 0;
 126         bio_for_each_segment(vec, bio, idx) {
 127                 if (unlikely(phys_mem + vec->bv_len > phys_end)) {
 128                         bio_io_error(bio, bio->bi_size);
 129                         rc = -ERANGE;
 130                         break;
 131                 }
 132
 133                 user_mem = page_address(vec->bv_page) + vec->bv_offset;
 134                 if (bio_data_dir(bio) == READ)
 135                         memcpy(user_mem, (void *) phys_mem, vec->bv_len);
 136                 else
 137                         memcpy((void *) phys_mem, user_mem, vec->bv_len);
 138
 139                 phys_mem += vec->bv_len;
 140                 transfered += vec->bv_len;
 141         }
 142         bio_endio(bio, transfered, 0);
 143
 144         return rc;
 145 }
 146
 147 /**
 148  * axon_ram_direct_access - direct_access() method for block device
 149  * @device, @sector, @data: see block_device_operations method
 150  */
 151 static int
 152 axon_ram_direct_access(struct block_device *device, sector_t sector,
 153                        unsigned long *data)
 154 {
 155         struct axon_ram_bank *bank = device->bd_disk->private_data;
 156         loff_t offset;
 157
 158         offset = sector << AXON_RAM_SECTOR_SHIFT;
 159         if (offset >= bank->size) {
 160                 dev_err(&bank->device->dev, "Access outside of address space\n");
 161                 return -ERANGE;
 162         }
 163
 164         *data = bank->ph_addr + offset;
 165
 166         return 0;
 167 }
 168
 169 static struct block_device_operations axon_ram_devops = {
 170         .owner          = THIS_MODULE,
 171         .direct_access  = axon_ram_direct_access
 172 };
 173
 174 /**
 175  * axon_ram_probe - probe() method for platform driver
 176  * @device, @device_id: see of_platform_driver method
 177  */
 178 static int
 179 axon_ram_probe(struct of_device *device, const struct of_device_id *device_id)
 180 {
 181         static int axon_ram_bank_id = -1;
 182         struct axon_ram_bank *bank;
 183         struct resource resource;
 184         int rc = 0;
 185
 186         axon_ram_bank_id++;
 187
 188         dev_info(&device->dev, "Found memory controller on %s\n",
 189                         device->node->full_name);
 190
 191         bank = kzalloc(sizeof(struct axon_ram_bank), GFP_KERNEL);
 192         if (bank == NULL) {
 193                 dev_err(&device->dev, "Out of memory\n");
 194                 rc = -ENOMEM;
 195                 goto failed;
 196         }
 197
 198         device->dev.platform_data = bank;
 199
 200         bank->device = device;
 201
 202         if (of_address_to_resource(device->node, 0, &resource) != 0) {
 203                 dev_err(&device->dev, "Cannot access device tree\n");
 204                 rc = -EFAULT;
 205                 goto failed;
 206         }
 207
 208         bank->size = resource.end - resource.start + 1;
 209
 210         if (bank->size == 0) {
 211                 dev_err(&device->dev, "No DDR2 memory found for %s%d\n",
 212                                 AXON_RAM_DEVICE_NAME, axon_ram_bank_id);
 213                 rc = -ENODEV;
 214                 goto failed;
 215         }
 216
 217         dev_info(&device->dev, "Register DDR2 memory device %s%d with %luMB\n",
 218                         AXON_RAM_DEVICE_NAME, axon_ram_bank_id, bank->size >> 20);
 219
 220         bank->ph_addr = resource.start;
 221         bank->io_addr = (unsigned long) ioremap_flags(
 222                         bank->ph_addr, bank->size, _PAGE_NO_CACHE);
 223         if (bank->io_addr == 0) {
 224                 dev_err(&device->dev, "ioremap() failed\n");
 225                 rc = -EFAULT;
 226                 goto failed;
 227         }
 228
 229         bank->disk = alloc_disk(AXON_RAM_MINORS_PER_DISK);
 230         if (bank->disk == NULL) {
 231                 dev_err(&device->dev, "Cannot register disk\n");
 232                 rc = -EFAULT;
 233                 goto failed;
 234         }
 235
 236         bank->disk->first_minor = 0;
 237         bank->disk->fops = &axon_ram_devops;
 238         bank->disk->private_data = bank;
 239         bank->disk->driverfs_dev = &device->dev;
 240
 241         sprintf(bank->disk->disk_name, "%s%d",
 242                         AXON_RAM_DEVICE_NAME, axon_ram_bank_id);
 243         bank->disk->major = register_blkdev(0, bank->disk->disk_name);
 244         if (bank->disk->major < 0) {
 245                 dev_err(&device->dev, "Cannot register block device\n");
 246                 rc = -EFAULT;
 247                 goto failed;
 248         }
 249
 250         bank->disk->queue = blk_alloc_queue(GFP_KERNEL);
 251         if (bank->disk->queue == NULL) {
 252                 dev_err(&device->dev, "Cannot register disk queue\n");
 253                 rc = -EFAULT;
 254                 goto failed;
 255         }
 256
 257         set_capacity(bank->disk, bank->size >> AXON_RAM_SECTOR_SHIFT);
 258         blk_queue_make_request(bank->disk->queue, axon_ram_make_request);
 259         blk_queue_hardsect_size(bank->disk->queue, AXON_RAM_SECTOR_SIZE);
 260         add_disk(bank->disk);
 261
 262         bank->irq_correctable = irq_of_parse_and_map(device->node, 0);
 263         bank->irq_uncorrectable = irq_of_parse_and_map(device->node, 1);
 264         if ((bank->irq_correctable <= 0) || (bank->irq_uncorrectable <= 0)) {
 265                 dev_err(&device->dev, "Cannot access ECC interrupt ID\n");
 266                 rc = -EFAULT;
 267                 goto failed;
 268         }
 269
 270         rc = request_irq(bank->irq_correctable, axon_ram_irq_handler,
 271                         AXON_RAM_IRQ_FLAGS, bank->disk->disk_name, device);
 272         if (rc != 0) {
 273                 dev_err(&device->dev, "Cannot register ECC interrupt handler\n");
 274                 bank->irq_correctable = bank->irq_uncorrectable = 0;
 275                 rc = -EFAULT;
 276                 goto failed;
 277         }
 278
 279         rc = request_irq(bank->irq_uncorrectable, axon_ram_irq_handler,
 280                         AXON_RAM_IRQ_FLAGS, bank->disk->disk_name, device);
 281         if (rc != 0) {
 282                 dev_err(&device->dev, "Cannot register ECC interrupt handler\n");
 283                 bank->irq_uncorrectable = 0;
 284                 rc = -EFAULT;
 285                 goto failed;
 286         }
 287
 288         rc = device_create_file(&device->dev, &dev_attr_ecc);
 289         if (rc != 0) {
 290                 dev_err(&device->dev, "Cannot create sysfs file\n");
 291                 rc = -EFAULT;
 292                 goto failed;
 293         }
 294
 295         return 0;
 296
 297 failed:
 298         if (bank != NULL) {
 299                 if (bank->irq_uncorrectable > 0)
 300                         free_irq(bank->irq_uncorrectable, device);
 301                 if (bank->irq_correctable > 0)
 302                         free_irq(bank->irq_correctable, device);
 303                 if (bank->disk != NULL) {
 304                         if (bank->disk->queue != NULL)
 305                                 blk_cleanup_queue(bank->disk->queue);
 306                         if (bank->disk->major > 0)
 307                                 unregister_blkdev(bank->disk->major,
 308                                                 bank->disk->disk_name);
 309                         del_gendisk(bank->disk);
 310                 }
 311                 device->dev.platform_data = NULL;
 312                 if (bank->io_addr != 0)
 313                         iounmap((void __iomem *) bank->io_addr);
 314                 kfree(bank);
 315         }
 316
 317         return rc;
 318 }
 319
 320 /**
 321  * axon_ram_remove - remove() method for platform driver
 322  * @device: see of_platform_driver method
 323  */
 324 static int
 325 axon_ram_remove(struct of_device *device)
 326 {
 327         struct axon_ram_bank *bank = device->dev.platform_data;
 328
 329         BUG_ON(!bank || !bank->disk);
 330
 331         device_remove_file(&device->dev, &dev_attr_ecc);
 332         free_irq(bank->irq_uncorrectable, device);
 333         free_irq(bank->irq_correctable, device);
 334         blk_cleanup_queue(bank->disk->queue);
 335         unregister_blkdev(bank->disk->major, bank->disk->disk_name);
 336         del_gendisk(bank->disk);
 337         iounmap((void __iomem *) bank->io_addr);
 338         kfree(bank);
 339
 340         return 0;
 341 }
 342
 343 static struct of_device_id axon_ram_device_id[] = {
 344         {
 345                 .type   = "dma-memory"
 346         },
 347         {}
 348 };
 349
 350 static struct of_platform_driver axon_ram_driver = {
 351         .owner          = THIS_MODULE,
 352         .name           = AXON_RAM_MODULE_NAME,
 353         .match_table    = axon_ram_device_id,
 354         .probe          = axon_ram_probe,
 355         .remove         = axon_ram_remove
 356 };
 357
 358 /**
 359  * axon_ram_init
 360  */
 361 static int __init
 362 axon_ram_init(void)
 363 {
 364         return of_register_platform_driver(&axon_ram_driver);
 365 }
 366
 367 /**
 368  * axon_ram_exit
 369  */
 370 static void __exit
 371 axon_ram_exit(void)
 372 {
 373         of_unregister_platform_driver(&axon_ram_driver);
 374 }
 375
 376 module_init(axon_ram_init);
 377 module_exit(axon_ram_exit);
 378
 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");