drivers/block/z2ram.c

   1 /*
   2 ** z2ram - Amiga pseudo-driver to access 16bit-RAM in ZorroII space
   3 **         as a block device, to be used as a RAM disk or swap space
   4 **
   5 ** Copyright (C) 1994 by Ingo Wilken (Ingo.Wilken@informatik.uni-oldenburg.de)
   6 **
   7 ** ++Geert: support for zorro_unused_z2ram, better range checking
   8 ** ++roman: translate accesses via an array
   9 ** ++Milan: support for ChipRAM usage
  10 ** ++yambo: converted to 2.0 kernel
  11 ** ++yambo: modularized and support added for 3 minor devices including:
  12 **          MAJOR  MINOR  DESCRIPTION
  13 **          -----  -----  ----------------------------------------------
  14 **          37     0       Use Zorro II and Chip ram
  15 **          37     1       Use only Zorro II ram
  16 **          37     2       Use only Chip ram
  17 **          37     4-7     Use memory list entry 1-4 (first is 0)
  18 ** ++jskov: support for 1-4th memory list entry.
  19 **
  20 ** Permission to use, copy, modify, and distribute this software and its
  21 ** documentation for any purpose and without fee is hereby granted, provided
  22 ** that the above copyright notice appear in all copies and that both that
  23 ** copyright notice and this permission notice appear in supporting
  24 ** documentation.  This software is provided "as is" without express or
  25 ** implied warranty.
  26 */
  27
  28 #define DEVICE_NAME "Z2RAM"
  29
  30 #include <linux/major.h>
  31 #include <linux/vmalloc.h>
  32 #include <linux/init.h>
  33 #include <linux/module.h>
  34 #include <linux/blk-mq.h>
  35 #include <linux/bitops.h>
  36 #include <linux/mutex.h>
  37 #include <linux/slab.h>
  38
  39 #include <asm/setup.h>
  40 #include <asm/amigahw.h>
  41 #include <asm/pgtable.h>
  42
  43 #include <linux/zorro.h>
  44
  45
  46 #define Z2MINOR_COMBINED      (0)
  47 #define Z2MINOR_Z2ONLY        (1)
  48 #define Z2MINOR_CHIPONLY      (2)
  49 #define Z2MINOR_MEMLIST1      (4)
  50 #define Z2MINOR_MEMLIST2      (5)
  51 #define Z2MINOR_MEMLIST3      (6)
  52 #define Z2MINOR_MEMLIST4      (7)
  53 #define Z2MINOR_COUNT         (8) /* Move this down when adding a new minor */
  54
  55 #define Z2RAM_CHUNK1024       ( Z2RAM_CHUNKSIZE >> 10 )
  56
  57 static DEFINE_MUTEX(z2ram_mutex);
  58 static u_long *z2ram_map    = NULL;
  59 static u_long z2ram_size    = 0;
  60 static int z2_count         = 0;
  61 static int chip_count       = 0;
  62 static int list_count       = 0;
  63 static int current_device   = -1;
  64
  65 static DEFINE_SPINLOCK(z2ram_lock);
  66
  67 static struct gendisk *z2ram_gendisk;
  68
  69 static blk_status_t z2_queue_rq(struct blk_mq_hw_ctx *hctx,
  70                                 const struct blk_mq_queue_data *bd)
  71 {
  72         struct request *req = bd->rq;
  73         unsigned long start = blk_rq_pos(req) << 9;
  74         unsigned long len  = blk_rq_cur_bytes(req);
  75
  76         blk_mq_start_request(req);
  77
  78         if (start + len > z2ram_size) {
  79                 pr_err(DEVICE_NAME ": bad access: block=%llu, "
  80                        "count=%u\n",
  81                        (unsigned long long)blk_rq_pos(req),
  82                        blk_rq_cur_sectors(req));
  83                 return BLK_STS_IOERR;
  84         }
  85
  86         spin_lock_irq(&z2ram_lock);
  87
  88         while (len) {
  89                 unsigned long addr = start & Z2RAM_CHUNKMASK;
  90                 unsigned long size = Z2RAM_CHUNKSIZE - addr;
  91                 void *buffer = bio_data(req->bio);
  92
  93                 if (len < size)
  94                         size = len;
  95                 addr += z2ram_map[ start >> Z2RAM_CHUNKSHIFT ];
  96                 if (rq_data_dir(req) == READ)
  97                         memcpy(buffer, (char *)addr, size);
  98                 else
  99                         memcpy((char *)addr, buffer, size);
 100                 start += size;
 101                 len -= size;
 102         }
 103
 104         spin_unlock_irq(&z2ram_lock);
 105         blk_mq_end_request(req, BLK_STS_OK);
 106         return BLK_STS_OK;
 107 }
 108
 109 static void
 110 get_z2ram( void )
 111 {
 112     int i;
 113
 114     for ( i = 0; i < Z2RAM_SIZE / Z2RAM_CHUNKSIZE; i++ )
 115     {
 116         if ( test_bit( i, zorro_unused_z2ram ) )
 117         {
 118             z2_count++;
 119             z2ram_map[z2ram_size++] = (unsigned long)ZTWO_VADDR(Z2RAM_START) +
 120                                       (i << Z2RAM_CHUNKSHIFT);
 121             clear_bit( i, zorro_unused_z2ram );
 122         }
 123     }
 124
 125     return;
 126 }
 127
 128 static void
 129 get_chipram( void )
 130 {
 131
 132     while ( amiga_chip_avail() > ( Z2RAM_CHUNKSIZE * 4 ) )
 133     {
 134         chip_count++;
 135         z2ram_map[ z2ram_size ] =
 136             (u_long)amiga_chip_alloc( Z2RAM_CHUNKSIZE, "z2ram" );
 137
 138         if ( z2ram_map[ z2ram_size ] == 0 )
 139         {
 140             break;
 141         }
 142
 143         z2ram_size++;
 144     }
 145
 146     return;
 147 }
 148
 149 static int z2_open(struct block_device *bdev, fmode_t mode)
 150 {
 151     int device;
 152     int max_z2_map = ( Z2RAM_SIZE / Z2RAM_CHUNKSIZE ) *
 153         sizeof( z2ram_map[0] );
 154     int max_chip_map = ( amiga_chip_size / Z2RAM_CHUNKSIZE ) *
 155         sizeof( z2ram_map[0] );
 156     int rc = -ENOMEM;
 157
 158     device = MINOR(bdev->bd_dev);
 159
 160     mutex_lock(&z2ram_mutex);
 161     if ( current_device != -1 && current_device != device )
 162     {
 163         rc = -EBUSY;
 164         goto err_out;
 165     }
 166
 167     if ( current_device == -1 )
 168     {
 169         z2_count   = 0;
 170         chip_count = 0;
 171         list_count = 0;
 172         z2ram_size = 0;
 173
 174         /* Use a specific list entry. */
 175         if (device >= Z2MINOR_MEMLIST1 && device <= Z2MINOR_MEMLIST4) {
 176                 int index = device - Z2MINOR_MEMLIST1 + 1;
 177                 unsigned long size, paddr, vaddr;
 178
 179                 if (index >= m68k_realnum_memory) {
 180                         printk( KERN_ERR DEVICE_NAME
 181                                 ": no such entry in z2ram_map\n" );
 182                         goto err_out;
 183                 }
 184
 185                 paddr = m68k_memory[index].addr;
 186                 size = m68k_memory[index].size & ~(Z2RAM_CHUNKSIZE-1);
 187
 188 #ifdef __powerpc__
 189                 /* FIXME: ioremap doesn't build correct memory tables. */
 190                 {
 191                         vfree(vmalloc (size));
 192                 }
 193
 194                 vaddr = (unsigned long)ioremap_wt(paddr, size);
 195
 196 #else
 197                 vaddr = (unsigned long)z_remap_nocache_nonser(paddr, size);
 198 #endif
 199                 z2ram_map =
 200                         kmalloc_array(size / Z2RAM_CHUNKSIZE,
 201                                       sizeof(z2ram_map[0]),
 202                                       GFP_KERNEL);
 203                 if ( z2ram_map == NULL )
 204                 {
 205                     printk( KERN_ERR DEVICE_NAME
 206                         ": cannot get mem for z2ram_map\n" );
 207                     goto err_out;
 208                 }
 209
 210                 while (size) {
 211                         z2ram_map[ z2ram_size++ ] = vaddr;
 212                         size -= Z2RAM_CHUNKSIZE;
 213                         vaddr += Z2RAM_CHUNKSIZE;
 214                         list_count++;
 215                 }
 216
 217                 if ( z2ram_size != 0 )
 218                     printk( KERN_INFO DEVICE_NAME
 219                         ": using %iK List Entry %d Memory\n",
 220                         list_count * Z2RAM_CHUNK1024, index );
 221         } else
 222
 223         switch ( device )
 224         {
 225             case Z2MINOR_COMBINED:
 226
 227                 z2ram_map = kmalloc( max_z2_map + max_chip_map, GFP_KERNEL );
 228                 if ( z2ram_map == NULL )
 229                 {
 230                     printk( KERN_ERR DEVICE_NAME
 231                         ": cannot get mem for z2ram_map\n" );
 232                     goto err_out;
 233                 }
 234
 235                 get_z2ram();
 236                 get_chipram();
 237
 238                 if ( z2ram_size != 0 )
 239                     printk( KERN_INFO DEVICE_NAME
 240                         ": using %iK Zorro II RAM and %iK Chip RAM (Total %dK)\n",
 241                         z2_count * Z2RAM_CHUNK1024,
 242                         chip_count * Z2RAM_CHUNK1024,
 243                         ( z2_count + chip_count ) * Z2RAM_CHUNK1024 );
 244
 245             break;
 246
 247             case Z2MINOR_Z2ONLY:
 248                 z2ram_map = kmalloc( max_z2_map, GFP_KERNEL );
 249                 if ( z2ram_map == NULL )
 250                 {
 251                     printk( KERN_ERR DEVICE_NAME
 252                         ": cannot get mem for z2ram_map\n" );
 253                     goto err_out;
 254                 }
 255
 256                 get_z2ram();
 257
 258                 if ( z2ram_size != 0 )
 259                     printk( KERN_INFO DEVICE_NAME
 260                         ": using %iK of Zorro II RAM\n",
 261                         z2_count * Z2RAM_CHUNK1024 );
 262
 263             break;
 264
 265             case Z2MINOR_CHIPONLY:
 266                 z2ram_map = kmalloc( max_chip_map, GFP_KERNEL );
 267                 if ( z2ram_map == NULL )
 268                 {
 269                     printk( KERN_ERR DEVICE_NAME
 270                         ": cannot get mem for z2ram_map\n" );
 271                     goto err_out;
 272                 }
 273
 274                 get_chipram();
 275
 276                 if ( z2ram_size != 0 )
 277                     printk( KERN_INFO DEVICE_NAME
 278                         ": using %iK Chip RAM\n",
 279                         chip_count * Z2RAM_CHUNK1024 );
 280
 281             break;
 282
 283             default:
 284                 rc = -ENODEV;
 285                 goto err_out;
 286
 287             break;
 288         }
 289
 290         if ( z2ram_size == 0 )
 291         {
 292             printk( KERN_NOTICE DEVICE_NAME
 293                 ": no unused ZII/Chip RAM found\n" );
 294             goto err_out_kfree;
 295         }
 296
 297         current_device = device;
 298         z2ram_size <<= Z2RAM_CHUNKSHIFT;
 299         set_capacity(z2ram_gendisk, z2ram_size >> 9);
 300     }
 301
 302     mutex_unlock(&z2ram_mutex);
 303     return 0;
 304
 305 err_out_kfree:
 306     kfree(z2ram_map);
 307 err_out:
 308     mutex_unlock(&z2ram_mutex);
 309     return rc;
 310 }
 311
 312 static void
 313 z2_release(struct gendisk *disk, fmode_t mode)
 314 {
 315     mutex_lock(&z2ram_mutex);
 316     if ( current_device == -1 ) {
 317         mutex_unlock(&z2ram_mutex);
 318         return;
 319     }
 320     mutex_unlock(&z2ram_mutex);
 321     /*
 322      * FIXME: unmap memory
 323      */
 324 }
 325
 326 static const struct block_device_operations z2_fops =
 327 {
 328         .owner          = THIS_MODULE,
 329         .open           = z2_open,
 330         .release        = z2_release,
 331 };
 332
 333 static struct kobject *z2_find(dev_t dev, int *part, void *data)
 334 {
 335         *part = 0;
 336         return get_disk_and_module(z2ram_gendisk);
 337 }
 338
 339 static struct request_queue *z2_queue;
 340 static struct blk_mq_tag_set tag_set;
 341
 342 static const struct blk_mq_ops z2_mq_ops = {
 343         .queue_rq       = z2_queue_rq,
 344 };
 345
 346 static int __init
 347 z2_init(void)
 348 {
 349     int ret;
 350
 351     if (!MACH_IS_AMIGA)
 352         return -ENODEV;
 353
 354     ret = -EBUSY;
 355     if (register_blkdev(Z2RAM_MAJOR, DEVICE_NAME))
 356         goto err;
 357
 358     ret = -ENOMEM;
 359     z2ram_gendisk = alloc_disk(1);
 360     if (!z2ram_gendisk)
 361         goto out_disk;
 362
 363     z2_queue = blk_mq_init_sq_queue(&tag_set, &z2_mq_ops, 16,
 364                                         BLK_MQ_F_SHOULD_MERGE);
 365     if (IS_ERR(z2_queue)) {
 366         ret = PTR_ERR(z2_queue);
 367         z2_queue = NULL;
 368         goto out_queue;
 369     }
 370
 371     z2ram_gendisk->major = Z2RAM_MAJOR;
 372     z2ram_gendisk->first_minor = 0;
 373     z2ram_gendisk->fops = &z2_fops;
 374     sprintf(z2ram_gendisk->disk_name, "z2ram");
 375
 376     z2ram_gendisk->queue = z2_queue;
 377     add_disk(z2ram_gendisk);
 378     blk_register_region(MKDEV(Z2RAM_MAJOR, 0), Z2MINOR_COUNT, THIS_MODULE,
 379                                 z2_find, NULL, NULL);
 380
 381     return 0;
 382
 383 out_queue:
 384     put_disk(z2ram_gendisk);
 385 out_disk:
 386     unregister_blkdev(Z2RAM_MAJOR, DEVICE_NAME);
 387 err:
 388     return ret;
 389 }
 390
 391 static void __exit z2_exit(void)
 392 {
 393     int i, j;
 394     blk_unregister_region(MKDEV(Z2RAM_MAJOR, 0), Z2MINOR_COUNT);
 395     unregister_blkdev(Z2RAM_MAJOR, DEVICE_NAME);
 396     del_gendisk(z2ram_gendisk);
 397     put_disk(z2ram_gendisk);
 398     blk_cleanup_queue(z2_queue);
 399     blk_mq_free_tag_set(&tag_set);
 400
 401     if ( current_device != -1 )
 402     {
 403         i = 0;
 404
 405         for ( j = 0 ; j < z2_count; j++ )
 406         {
 407             set_bit( i++, zorro_unused_z2ram );
 408         }
 409
 410         for ( j = 0 ; j < chip_count; j++ )
 411         {
 412             if ( z2ram_map[ i ] )
 413             {
 414                 amiga_chip_free( (void *) z2ram_map[ i++ ] );
 415             }
 416         }
 417
 418         if ( z2ram_map != NULL )
 419         {
 420             kfree( z2ram_map );
 421         }
 422     }
 423
 424     return;
 425 }
 426
 427 module_init(z2_init);
 428 module_exit(z2_exit);
 429 MODULE_LICENSE("GPL");