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/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 #include <linux/pfn_t.h>
  47
  48 #include <asm/page.h>
  49 #include <asm/prom.h>
  50
  51 #define AXON_RAM_MODULE_NAME            "axonram"
  52 #define AXON_RAM_DEVICE_NAME            "axonram"
  53 #define AXON_RAM_MINORS_PER_DISK        16
  54 #define AXON_RAM_BLOCK_SHIFT            PAGE_SHIFT
  55 #define AXON_RAM_BLOCK_SIZE             1 << AXON_RAM_BLOCK_SHIFT
  56 #define AXON_RAM_SECTOR_SHIFT           9
  57 #define AXON_RAM_SECTOR_SIZE            1 << AXON_RAM_SECTOR_SHIFT
  58 #define AXON_RAM_IRQ_FLAGS              IRQF_SHARED | IRQF_TRIGGER_RISING
  59
  60 static int azfs_major, azfs_minor;
  61
  62 struct axon_ram_bank {
  63         struct platform_device  *device;
  64         struct gendisk          *disk;
  65         unsigned int            irq_id;
  66         unsigned long           ph_addr;
  67         unsigned long           io_addr;
  68         unsigned long           size;
  69         unsigned long           ecc_counter;
  70 };
  71
  72 static ssize_t
  73 axon_ram_sysfs_ecc(struct device *dev, struct device_attribute *attr, char *buf)
  74 {
  75         struct platform_device *device = to_platform_device(dev);
  76         struct axon_ram_bank *bank = device->dev.platform_data;
  77
  78         BUG_ON(!bank);
  79
  80         return sprintf(buf, "%ld\n", bank->ecc_counter);
  81 }
  82
  83 static DEVICE_ATTR(ecc, S_IRUGO, axon_ram_sysfs_ecc, NULL);
  84
  85 /**
  86  * axon_ram_irq_handler - interrupt handler for Axon RAM ECC
  87  * @irq: interrupt ID
  88  * @dev: pointer to of_device
  89  */
  90 static irqreturn_t
  91 axon_ram_irq_handler(int irq, void *dev)
  92 {
  93         struct platform_device *device = dev;
  94         struct axon_ram_bank *bank = device->dev.platform_data;
  95
  96         BUG_ON(!bank);
  97
  98         dev_err(&device->dev, "Correctable memory error occurred\n");
  99         bank->ecc_counter++;
 100         return IRQ_HANDLED;
 101 }
 102
 103 /**
 104  * axon_ram_make_request - make_request() method for block device
 105  * @queue, @bio: see blk_queue_make_request()
 106  */
 107 static blk_qc_t
 108 axon_ram_make_request(struct request_queue *queue, struct bio *bio)
 109 {
 110         struct axon_ram_bank *bank = bio->bi_bdev->bd_disk->private_data;
 111         unsigned long phys_mem, phys_end;
 112         void *user_mem;
 113         struct bio_vec vec;
 114         unsigned int transfered;
 115         struct bvec_iter iter;
 116
 117         phys_mem = bank->io_addr + (bio->bi_iter.bi_sector <<
 118                                     AXON_RAM_SECTOR_SHIFT);
 119         phys_end = bank->io_addr + bank->size;
 120         transfered = 0;
 121         bio_for_each_segment(vec, bio, iter) {
 122                 if (unlikely(phys_mem + vec.bv_len > phys_end)) {
 123                         bio_io_error(bio);
 124                         return BLK_QC_T_NONE;
 125                 }
 126
 127                 user_mem = page_address(vec.bv_page) + vec.bv_offset;
 128                 if (bio_data_dir(bio) == READ)
 129                         memcpy(user_mem, (void *) phys_mem, vec.bv_len);
 130                 else
 131                         memcpy((void *) phys_mem, user_mem, vec.bv_len);
 132
 133                 phys_mem += vec.bv_len;
 134                 transfered += vec.bv_len;
 135         }
 136         bio_endio(bio);
 137         return BLK_QC_T_NONE;
 138 }
 139
 140 /**
 141  * axon_ram_direct_access - direct_access() method for block device
 142  * @device, @sector, @data: see block_device_operations method
 143  */
 144 static long
 145 axon_ram_direct_access(struct block_device *device, sector_t sector,
 146                        void **kaddr, pfn_t *pfn, long size)
 147 {
 148         struct axon_ram_bank *bank = device->bd_disk->private_data;
 149         loff_t offset = (loff_t)sector << AXON_RAM_SECTOR_SHIFT;
 150
 151         *kaddr = (void *) bank->io_addr + offset;
 152         *pfn = phys_to_pfn_t(bank->ph_addr + offset, PFN_DEV);
 153         return bank->size - offset;
 154 }
 155
 156 static const struct block_device_operations axon_ram_devops = {
 157         .owner          = THIS_MODULE,
 158         .direct_access  = axon_ram_direct_access
 159 };
 160
 161 /**
 162  * axon_ram_probe - probe() method for platform driver
 163  * @device: see platform_driver method
 164  */
 165 static int axon_ram_probe(struct platform_device *device)
 166 {
 167         static int axon_ram_bank_id = -1;
 168         struct axon_ram_bank *bank;
 169         struct resource resource;
 170         int rc = 0;
 171
 172         axon_ram_bank_id++;
 173
 174         dev_info(&device->dev, "Found memory controller on %s\n",
 175                         device->dev.of_node->full_name);
 176
 177         bank = kzalloc(sizeof(struct axon_ram_bank), GFP_KERNEL);
 178         if (bank == NULL) {
 179                 dev_err(&device->dev, "Out of memory\n");
 180                 rc = -ENOMEM;
 181                 goto failed;
 182         }
 183
 184         device->dev.platform_data = bank;
 185
 186         bank->device = device;
 187
 188         if (of_address_to_resource(device->dev.of_node, 0, &resource) != 0) {
 189                 dev_err(&device->dev, "Cannot access device tree\n");
 190                 rc = -EFAULT;
 191                 goto failed;
 192         }
 193
 194         bank->size = resource_size(&resource);
 195
 196         if (bank->size == 0) {
 197                 dev_err(&device->dev, "No DDR2 memory found for %s%d\n",
 198                                 AXON_RAM_DEVICE_NAME, axon_ram_bank_id);
 199                 rc = -ENODEV;
 200                 goto failed;
 201         }
 202
 203         dev_info(&device->dev, "Register DDR2 memory device %s%d with %luMB\n",
 204                         AXON_RAM_DEVICE_NAME, axon_ram_bank_id, bank->size >> 20);
 205
 206         bank->ph_addr = resource.start;
 207         bank->io_addr = (unsigned long) ioremap_prot(
 208                         bank->ph_addr, bank->size, _PAGE_NO_CACHE);
 209         if (bank->io_addr == 0) {
 210                 dev_err(&device->dev, "ioremap() failed\n");
 211                 rc = -EFAULT;
 212                 goto failed;
 213         }
 214
 215         bank->disk = alloc_disk(AXON_RAM_MINORS_PER_DISK);
 216         if (bank->disk == NULL) {
 217                 dev_err(&device->dev, "Cannot register disk\n");
 218                 rc = -EFAULT;
 219                 goto failed;
 220         }
 221
 222         bank->disk->major = azfs_major;
 223         bank->disk->first_minor = azfs_minor;
 224         bank->disk->fops = &axon_ram_devops;
 225         bank->disk->private_data = bank;
 226         bank->disk->driverfs_dev = &device->dev;
 227
 228         sprintf(bank->disk->disk_name, "%s%d",
 229                         AXON_RAM_DEVICE_NAME, axon_ram_bank_id);
 230
 231         bank->disk->queue = blk_alloc_queue(GFP_KERNEL);
 232         if (bank->disk->queue == NULL) {
 233                 dev_err(&device->dev, "Cannot register disk queue\n");
 234                 rc = -EFAULT;
 235                 goto failed;
 236         }
 237
 238         set_capacity(bank->disk, bank->size >> AXON_RAM_SECTOR_SHIFT);
 239         blk_queue_make_request(bank->disk->queue, axon_ram_make_request);
 240         blk_queue_logical_block_size(bank->disk->queue, AXON_RAM_SECTOR_SIZE);
 241         add_disk(bank->disk);
 242
 243         bank->irq_id = irq_of_parse_and_map(device->dev.of_node, 0);
 244         if (bank->irq_id == NO_IRQ) {
 245                 dev_err(&device->dev, "Cannot access ECC interrupt ID\n");
 246                 rc = -EFAULT;
 247                 goto failed;
 248         }
 249
 250         rc = request_irq(bank->irq_id, axon_ram_irq_handler,
 251                         AXON_RAM_IRQ_FLAGS, bank->disk->disk_name, device);
 252         if (rc != 0) {
 253                 dev_err(&device->dev, "Cannot register ECC interrupt handler\n");
 254                 bank->irq_id = NO_IRQ;
 255                 rc = -EFAULT;
 256                 goto failed;
 257         }
 258
 259         rc = device_create_file(&device->dev, &dev_attr_ecc);
 260         if (rc != 0) {
 261                 dev_err(&device->dev, "Cannot create sysfs file\n");
 262                 rc = -EFAULT;
 263                 goto failed;
 264         }
 265
 266         azfs_minor += bank->disk->minors;
 267
 268         return 0;
 269
 270 failed:
 271         if (bank != NULL) {
 272                 if (bank->irq_id != NO_IRQ)
 273                         free_irq(bank->irq_id, device);
 274                 if (bank->disk != NULL) {
 275                         if (bank->disk->major > 0)
 276                                 unregister_blkdev(bank->disk->major,
 277                                                 bank->disk->disk_name);
 278                         del_gendisk(bank->disk);
 279                 }
 280                 device->dev.platform_data = NULL;
 281                 if (bank->io_addr != 0)
 282                         iounmap((void __iomem *) bank->io_addr);
 283                 kfree(bank);
 284         }
 285
 286         return rc;
 287 }
 288
 289 /**
 290  * axon_ram_remove - remove() method for platform driver
 291  * @device: see of_platform_driver method
 292  */
 293 static int
 294 axon_ram_remove(struct platform_device *device)
 295 {
 296         struct axon_ram_bank *bank = device->dev.platform_data;
 297
 298         BUG_ON(!bank || !bank->disk);
 299
 300         device_remove_file(&device->dev, &dev_attr_ecc);
 301         free_irq(bank->irq_id, device);
 302         del_gendisk(bank->disk);
 303         iounmap((void __iomem *) bank->io_addr);
 304         kfree(bank);
 305
 306         return 0;
 307 }
 308
 309 static const struct of_device_id axon_ram_device_id[] = {
 310         {
 311                 .type   = "dma-memory"
 312         },
 313         {}
 314 };
 315 MODULE_DEVICE_TABLE(of, axon_ram_device_id);
 316
 317 static struct platform_driver axon_ram_driver = {
 318         .probe          = axon_ram_probe,
 319         .remove         = axon_ram_remove,
 320         .driver = {
 321                 .name = AXON_RAM_MODULE_NAME,
 322                 .of_match_table = axon_ram_device_id,
 323         },
 324 };
 325
 326 /**
 327  * axon_ram_init
 328  */
 329 static int __init
 330 axon_ram_init(void)
 331 {
 332         azfs_major = register_blkdev(azfs_major, AXON_RAM_DEVICE_NAME);
 333         if (azfs_major < 0) {
 334                 printk(KERN_ERR "%s cannot become block device major number\n",
 335                                 AXON_RAM_MODULE_NAME);
 336                 return -EFAULT;
 337         }
 338         azfs_minor = 0;
 339
 340         return platform_driver_register(&axon_ram_driver);
 341 }
 342
 343 /**
 344  * axon_ram_exit
 345  */
 346 static void __exit
 347 axon_ram_exit(void)
 348 {
 349         platform_driver_unregister(&axon_ram_driver);
 350         unregister_blkdev(azfs_major, AXON_RAM_DEVICE_NAME);
 351 }
 352
 353 module_init(axon_ram_init);
 354 module_exit(axon_ram_exit);
 355
 356 MODULE_LICENSE("GPL");
 357 MODULE_AUTHOR("Maxim Shchetynin <maxim@de.ibm.com>");
 358 MODULE_DESCRIPTION("Axon DDR2 RAM device driver for IBM Cell BE");