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