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 #include <linux/pgtable.h>
  39
  40 #include <asm/setup.h>
  41 #include <asm/amigahw.h>
  42
  43 #include <linux/zorro.h>
  44
  45 #define Z2MINOR_COMBINED      (0)
  46 #define Z2MINOR_Z2ONLY        (1)
  47 #define Z2MINOR_CHIPONLY      (2)
  48 #define Z2MINOR_MEMLIST1      (4)
  49 #define Z2MINOR_MEMLIST2      (5)
  50 #define Z2MINOR_MEMLIST3      (6)
  51 #define Z2MINOR_MEMLIST4      (7)
  52 #define Z2MINOR_COUNT         (8)       /* Move this down when adding a new minor */
  53
  54 #define Z2RAM_CHUNK1024       ( Z2RAM_CHUNKSIZE >> 10 )
  55
  56 static DEFINE_MUTEX(z2ram_mutex);
  57 static u_long *z2ram_map = NULL;
  58 static u_long z2ram_size = 0;
  59 static int z2_count = 0;
  60 static int chip_count = 0;
  61 static int list_count = 0;
  62 static int current_device = -1;
  63
  64 static DEFINE_SPINLOCK(z2ram_lock);
  65
  66 static struct gendisk *z2ram_gendisk[Z2MINOR_COUNT];
  67
  68 static blk_status_t z2_queue_rq(struct blk_mq_hw_ctx *hctx,
  69                                 const struct blk_mq_queue_data *bd)
  70 {
  71         struct request *req = bd->rq;
  72         unsigned long start = blk_rq_pos(req) << 9;
  73         unsigned long len = blk_rq_cur_bytes(req);
  74
  75         blk_mq_start_request(req);
  76
  77         if (start + len > z2ram_size) {
  78                 pr_err(DEVICE_NAME ": bad access: block=%llu, "
  79                        "count=%u\n",
  80                        (unsigned long long)blk_rq_pos(req),
  81                        blk_rq_cur_sectors(req));
  82                 return BLK_STS_IOERR;
  83         }
  84
  85         spin_lock_irq(&z2ram_lock);
  86
  87         while (len) {
  88                 unsigned long addr = start & Z2RAM_CHUNKMASK;
  89                 unsigned long size = Z2RAM_CHUNKSIZE - addr;
  90                 void *buffer = bio_data(req->bio);
  91
  92                 if (len < size)
  93                         size = len;
  94                 addr += z2ram_map[start >> Z2RAM_CHUNKSHIFT];
  95                 if (rq_data_dir(req) == READ)
  96                         memcpy(buffer, (char *)addr, size);
  97                 else
  98                         memcpy((char *)addr, buffer, size);
  99                 start += size;
 100                 len -= size;
 101         }
 102
 103         spin_unlock_irq(&z2ram_lock);
 104         blk_mq_end_request(req, BLK_STS_OK);
 105         return BLK_STS_OK;
 106 }
 107
 108 static void get_z2ram(void)
 109 {
 110         int i;
 111
 112         for (i = 0; i < Z2RAM_SIZE / Z2RAM_CHUNKSIZE; i++) {
 113                 if (test_bit(i, zorro_unused_z2ram)) {
 114                         z2_count++;
 115                         z2ram_map[z2ram_size++] =
 116                             (unsigned long)ZTWO_VADDR(Z2RAM_START) +
 117                             (i << Z2RAM_CHUNKSHIFT);
 118                         clear_bit(i, zorro_unused_z2ram);
 119                 }
 120         }
 121
 122         return;
 123 }
 124
 125 static void get_chipram(void)
 126 {
 127
 128         while (amiga_chip_avail() > (Z2RAM_CHUNKSIZE * 4)) {
 129                 chip_count++;
 130                 z2ram_map[z2ram_size] =
 131                     (u_long) amiga_chip_alloc(Z2RAM_CHUNKSIZE, "z2ram");
 132
 133                 if (z2ram_map[z2ram_size] == 0) {
 134                         break;
 135                 }
 136
 137                 z2ram_size++;
 138         }
 139
 140         return;
 141 }
 142
 143 static int z2_open(struct gendisk *disk, blk_mode_t mode)
 144 {
 145         int device = disk->first_minor;
 146         int max_z2_map = (Z2RAM_SIZE / Z2RAM_CHUNKSIZE) * sizeof(z2ram_map[0]);
 147         int max_chip_map = (amiga_chip_size / Z2RAM_CHUNKSIZE) *
 148             sizeof(z2ram_map[0]);
 149         int rc = -ENOMEM;
 150
 151         mutex_lock(&z2ram_mutex);
 152         if (current_device != -1 && current_device != device) {
 153                 rc = -EBUSY;
 154                 goto err_out;
 155         }
 156
 157         if (current_device == -1) {
 158                 z2_count = 0;
 159                 chip_count = 0;
 160                 list_count = 0;
 161                 z2ram_size = 0;
 162
 163                 /* Use a specific list entry. */
 164                 if (device >= Z2MINOR_MEMLIST1 && device <= Z2MINOR_MEMLIST4) {
 165                         int index = device - Z2MINOR_MEMLIST1 + 1;
 166                         unsigned long size, paddr, vaddr;
 167
 168                         if (index >= m68k_realnum_memory) {
 169                                 printk(KERN_ERR DEVICE_NAME
 170                                        ": no such entry in z2ram_map\n");
 171                                 goto err_out;
 172                         }
 173
 174                         paddr = m68k_memory[index].addr;
 175                         size = m68k_memory[index].size & ~(Z2RAM_CHUNKSIZE - 1);
 176
 177 #ifdef __powerpc__
 178                         /* FIXME: ioremap doesn't build correct memory tables. */
 179                         {
 180                                 vfree(vmalloc(size));
 181                         }
 182
 183                         vaddr = (unsigned long)ioremap_wt(paddr, size);
 184
 185 #else
 186                         vaddr =
 187                             (unsigned long)z_remap_nocache_nonser(paddr, size);
 188 #endif
 189                         z2ram_map =
 190                             kmalloc_array(size / Z2RAM_CHUNKSIZE,
 191                                           sizeof(z2ram_map[0]), GFP_KERNEL);
 192                         if (z2ram_map == NULL) {
 193                                 printk(KERN_ERR DEVICE_NAME
 194                                        ": cannot get mem for z2ram_map\n");
 195                                 goto err_out;
 196                         }
 197
 198                         while (size) {
 199                                 z2ram_map[z2ram_size++] = vaddr;
 200                                 size -= Z2RAM_CHUNKSIZE;
 201                                 vaddr += Z2RAM_CHUNKSIZE;
 202                                 list_count++;
 203                         }
 204
 205                         if (z2ram_size != 0)
 206                                 printk(KERN_INFO DEVICE_NAME
 207                                        ": using %iK List Entry %d Memory\n",
 208                                        list_count * Z2RAM_CHUNK1024, index);
 209                 } else
 210                         switch (device) {
 211                         case Z2MINOR_COMBINED:
 212
 213                                 z2ram_map =
 214                                     kmalloc(max_z2_map + max_chip_map,
 215                                             GFP_KERNEL);
 216                                 if (z2ram_map == NULL) {
 217                                         printk(KERN_ERR DEVICE_NAME
 218                                                ": cannot get mem for z2ram_map\n");
 219                                         goto err_out;
 220                                 }
 221
 222                                 get_z2ram();
 223                                 get_chipram();
 224
 225                                 if (z2ram_size != 0)
 226                                         printk(KERN_INFO DEVICE_NAME
 227                                                ": using %iK Zorro II RAM and %iK Chip RAM (Total %dK)\n",
 228                                                z2_count * Z2RAM_CHUNK1024,
 229                                                chip_count * Z2RAM_CHUNK1024,
 230                                                (z2_count +
 231                                                 chip_count) * Z2RAM_CHUNK1024);
 232
 233                                 break;
 234
 235                         case Z2MINOR_Z2ONLY:
 236                                 z2ram_map = kmalloc(max_z2_map, GFP_KERNEL);
 237                                 if (!z2ram_map)
 238                                         goto err_out;
 239
 240                                 get_z2ram();
 241
 242                                 if (z2ram_size != 0)
 243                                         printk(KERN_INFO DEVICE_NAME
 244                                                ": using %iK of Zorro II RAM\n",
 245                                                z2_count * Z2RAM_CHUNK1024);
 246
 247                                 break;
 248
 249                         case Z2MINOR_CHIPONLY:
 250                                 z2ram_map = kmalloc(max_chip_map, GFP_KERNEL);
 251                                 if (!z2ram_map)
 252                                         goto err_out;
 253
 254                                 get_chipram();
 255
 256                                 if (z2ram_size != 0)
 257                                         printk(KERN_INFO DEVICE_NAME
 258                                                ": using %iK Chip RAM\n",
 259                                                chip_count * Z2RAM_CHUNK1024);
 260
 261                                 break;
 262
 263                         default:
 264                                 rc = -ENODEV;
 265                                 goto err_out;
 266
 267                                 break;
 268                         }
 269
 270                 if (z2ram_size == 0) {
 271                         printk(KERN_NOTICE DEVICE_NAME
 272                                ": no unused ZII/Chip RAM found\n");
 273                         goto err_out_kfree;
 274                 }
 275
 276                 current_device = device;
 277                 z2ram_size <<= Z2RAM_CHUNKSHIFT;
 278                 set_capacity(z2ram_gendisk[device], z2ram_size >> 9);
 279         }
 280
 281         mutex_unlock(&z2ram_mutex);
 282         return 0;
 283
 284 err_out_kfree:
 285         kfree(z2ram_map);
 286 err_out:
 287         mutex_unlock(&z2ram_mutex);
 288         return rc;
 289 }
 290
 291 static void z2_release(struct gendisk *disk)
 292 {
 293         mutex_lock(&z2ram_mutex);
 294         if (current_device == -1) {
 295                 mutex_unlock(&z2ram_mutex);
 296                 return;
 297         }
 298         mutex_unlock(&z2ram_mutex);
 299         /*
 300          * FIXME: unmap memory
 301          */
 302 }
 303
 304 static const struct block_device_operations z2_fops = {
 305         .owner = THIS_MODULE,
 306         .open = z2_open,
 307         .release = z2_release,
 308 };
 309
 310 static struct blk_mq_tag_set tag_set;
 311
 312 static const struct blk_mq_ops z2_mq_ops = {
 313         .queue_rq = z2_queue_rq,
 314 };
 315
 316 static int z2ram_register_disk(int minor)
 317 {
 318         struct gendisk *disk;
 319         int err;
 320
 321         disk = blk_mq_alloc_disk(&tag_set, NULL, NULL);
 322         if (IS_ERR(disk))
 323                 return PTR_ERR(disk);
 324
 325         disk->major = Z2RAM_MAJOR;
 326         disk->first_minor = minor;
 327         disk->minors = 1;
 328         disk->flags |= GENHD_FL_NO_PART;
 329         disk->fops = &z2_fops;
 330         if (minor)
 331                 sprintf(disk->disk_name, "z2ram%d", minor);
 332         else
 333                 sprintf(disk->disk_name, "z2ram");
 334
 335         z2ram_gendisk[minor] = disk;
 336         err = add_disk(disk);
 337         if (err)
 338                 put_disk(disk);
 339         return err;
 340 }
 341
 342 static int __init z2_init(void)
 343 {
 344         int ret, i;
 345
 346         if (!MACH_IS_AMIGA)
 347                 return -ENODEV;
 348
 349         if (register_blkdev(Z2RAM_MAJOR, DEVICE_NAME))
 350                 return -EBUSY;
 351
 352         tag_set.ops = &z2_mq_ops;
 353         tag_set.nr_hw_queues = 1;
 354         tag_set.nr_maps = 1;
 355         tag_set.queue_depth = 16;
 356         tag_set.numa_node = NUMA_NO_NODE;
 357         tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
 358         ret = blk_mq_alloc_tag_set(&tag_set);
 359         if (ret)
 360                 goto out_unregister_blkdev;
 361
 362         for (i = 0; i < Z2MINOR_COUNT; i++) {
 363                 ret = z2ram_register_disk(i);
 364                 if (ret && i == 0)
 365                         goto out_free_tagset;
 366         }
 367
 368         return 0;
 369
 370 out_free_tagset:
 371         blk_mq_free_tag_set(&tag_set);
 372 out_unregister_blkdev:
 373         unregister_blkdev(Z2RAM_MAJOR, DEVICE_NAME);
 374         return ret;
 375 }
 376
 377 static void __exit z2_exit(void)
 378 {
 379         int i, j;
 380
 381         unregister_blkdev(Z2RAM_MAJOR, DEVICE_NAME);
 382
 383         for (i = 0; i < Z2MINOR_COUNT; i++) {
 384                 del_gendisk(z2ram_gendisk[i]);
 385                 put_disk(z2ram_gendisk[i]);
 386         }
 387         blk_mq_free_tag_set(&tag_set);
 388
 389         if (current_device != -1) {
 390                 i = 0;
 391
 392                 for (j = 0; j < z2_count; j++) {
 393                         set_bit(i++, zorro_unused_z2ram);
 394                 }
 395
 396                 for (j = 0; j < chip_count; j++) {
 397                         if (z2ram_map[i]) {
 398                                 amiga_chip_free((void *)z2ram_map[i++]);
 399                         }
 400                 }
 401
 402                 if (z2ram_map != NULL) {
 403                         kfree(z2ram_map);
 404                 }
 405         }
 406
 407         return;
 408 }
 409
 410 module_init(z2_init);
 411 module_exit(z2_exit);
 412 MODULE_LICENSE("GPL");