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 block_device *bdev, fmode_t mode)
 144 {
 145         int device;
 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         device = MINOR(bdev->bd_dev);
 152
 153         mutex_lock(&z2ram_mutex);
 154         if (current_device != -1 && current_device != device) {
 155                 rc = -EBUSY;
 156                 goto err_out;
 157         }
 158
 159         if (current_device == -1) {
 160                 z2_count = 0;
 161                 chip_count = 0;
 162                 list_count = 0;
 163                 z2ram_size = 0;
 164
 165                 /* Use a specific list entry. */
 166                 if (device >= Z2MINOR_MEMLIST1 && device <= Z2MINOR_MEMLIST4) {
 167                         int index = device - Z2MINOR_MEMLIST1 + 1;
 168                         unsigned long size, paddr, vaddr;
 169
 170                         if (index >= m68k_realnum_memory) {
 171                                 printk(KERN_ERR DEVICE_NAME
 172                                        ": no such entry in z2ram_map\n");
 173                                 goto err_out;
 174                         }
 175
 176                         paddr = m68k_memory[index].addr;
 177                         size = m68k_memory[index].size & ~(Z2RAM_CHUNKSIZE - 1);
 178
 179 #ifdef __powerpc__
 180                         /* FIXME: ioremap doesn't build correct memory tables. */
 181                         {
 182                                 vfree(vmalloc(size));
 183                         }
 184
 185                         vaddr = (unsigned long)ioremap_wt(paddr, size);
 186
 187 #else
 188                         vaddr =
 189                             (unsigned long)z_remap_nocache_nonser(paddr, size);
 190 #endif
 191                         z2ram_map =
 192                             kmalloc_array(size / Z2RAM_CHUNKSIZE,
 193                                           sizeof(z2ram_map[0]), GFP_KERNEL);
 194                         if (z2ram_map == NULL) {
 195                                 printk(KERN_ERR DEVICE_NAME
 196                                        ": cannot get mem for z2ram_map\n");
 197                                 goto err_out;
 198                         }
 199
 200                         while (size) {
 201                                 z2ram_map[z2ram_size++] = vaddr;
 202                                 size -= Z2RAM_CHUNKSIZE;
 203                                 vaddr += Z2RAM_CHUNKSIZE;
 204                                 list_count++;
 205                         }
 206
 207                         if (z2ram_size != 0)
 208                                 printk(KERN_INFO DEVICE_NAME
 209                                        ": using %iK List Entry %d Memory\n",
 210                                        list_count * Z2RAM_CHUNK1024, index);
 211                 } else
 212                         switch (device) {
 213                         case Z2MINOR_COMBINED:
 214
 215                                 z2ram_map =
 216                                     kmalloc(max_z2_map + max_chip_map,
 217                                             GFP_KERNEL);
 218                                 if (z2ram_map == NULL) {
 219                                         printk(KERN_ERR DEVICE_NAME
 220                                                ": cannot get mem for z2ram_map\n");
 221                                         goto err_out;
 222                                 }
 223
 224                                 get_z2ram();
 225                                 get_chipram();
 226
 227                                 if (z2ram_size != 0)
 228                                         printk(KERN_INFO DEVICE_NAME
 229                                                ": using %iK Zorro II RAM and %iK Chip RAM (Total %dK)\n",
 230                                                z2_count * Z2RAM_CHUNK1024,
 231                                                chip_count * Z2RAM_CHUNK1024,
 232                                                (z2_count +
 233                                                 chip_count) * Z2RAM_CHUNK1024);
 234
 235                                 break;
 236
 237                         case Z2MINOR_Z2ONLY:
 238                                 z2ram_map = kmalloc(max_z2_map, GFP_KERNEL);
 239                                 if (z2ram_map == NULL) {
 240                                         printk(KERN_ERR DEVICE_NAME
 241                                                ": cannot get mem for z2ram_map\n");
 242                                         goto err_out;
 243                                 }
 244
 245                                 get_z2ram();
 246
 247                                 if (z2ram_size != 0)
 248                                         printk(KERN_INFO DEVICE_NAME
 249                                                ": using %iK of Zorro II RAM\n",
 250                                                z2_count * Z2RAM_CHUNK1024);
 251
 252                                 break;
 253
 254                         case Z2MINOR_CHIPONLY:
 255                                 z2ram_map = kmalloc(max_chip_map, GFP_KERNEL);
 256                                 if (z2ram_map == NULL) {
 257                                         printk(KERN_ERR DEVICE_NAME
 258                                                ": cannot get mem for z2ram_map\n");
 259                                         goto err_out;
 260                                 }
 261
 262                                 get_chipram();
 263
 264                                 if (z2ram_size != 0)
 265                                         printk(KERN_INFO DEVICE_NAME
 266                                                ": using %iK Chip RAM\n",
 267                                                chip_count * Z2RAM_CHUNK1024);
 268
 269                                 break;
 270
 271                         default:
 272                                 rc = -ENODEV;
 273                                 goto err_out;
 274
 275                                 break;
 276                         }
 277
 278                 if (z2ram_size == 0) {
 279                         printk(KERN_NOTICE DEVICE_NAME
 280                                ": no unused ZII/Chip RAM found\n");
 281                         goto err_out_kfree;
 282                 }
 283
 284                 current_device = device;
 285                 z2ram_size <<= Z2RAM_CHUNKSHIFT;
 286                 set_capacity(z2ram_gendisk[device], z2ram_size >> 9);
 287         }
 288
 289         mutex_unlock(&z2ram_mutex);
 290         return 0;
 291
 292 err_out_kfree:
 293         kfree(z2ram_map);
 294 err_out:
 295         mutex_unlock(&z2ram_mutex);
 296         return rc;
 297 }
 298
 299 static void z2_release(struct gendisk *disk, fmode_t mode)
 300 {
 301         mutex_lock(&z2ram_mutex);
 302         if (current_device == -1) {
 303                 mutex_unlock(&z2ram_mutex);
 304                 return;
 305         }
 306         mutex_unlock(&z2ram_mutex);
 307         /*
 308          * FIXME: unmap memory
 309          */
 310 }
 311
 312 static const struct block_device_operations z2_fops = {
 313         .owner = THIS_MODULE,
 314         .open = z2_open,
 315         .release = z2_release,
 316 };
 317
 318 static struct blk_mq_tag_set tag_set;
 319
 320 static const struct blk_mq_ops z2_mq_ops = {
 321         .queue_rq = z2_queue_rq,
 322 };
 323
 324 static int z2ram_register_disk(int minor)
 325 {
 326         struct request_queue *q;
 327         struct gendisk *disk;
 328
 329         disk = alloc_disk(1);
 330         if (!disk)
 331                 return -ENOMEM;
 332
 333         q = blk_mq_init_queue(&tag_set);
 334         if (IS_ERR(q)) {
 335                 put_disk(disk);
 336                 return PTR_ERR(q);
 337         }
 338
 339         disk->major = Z2RAM_MAJOR;
 340         disk->first_minor = minor;
 341         disk->fops = &z2_fops;
 342         if (minor)
 343                 sprintf(disk->disk_name, "z2ram%d", minor);
 344         else
 345                 sprintf(disk->disk_name, "z2ram");
 346         disk->queue = q;
 347
 348         z2ram_gendisk[minor] = disk;
 349         add_disk(disk);
 350         return 0;
 351 }
 352
 353 static int __init z2_init(void)
 354 {
 355         int ret, i;
 356
 357         if (!MACH_IS_AMIGA)
 358                 return -ENODEV;
 359
 360         if (register_blkdev(Z2RAM_MAJOR, DEVICE_NAME))
 361                 return -EBUSY;
 362
 363         tag_set.ops = &z2_mq_ops;
 364         tag_set.nr_hw_queues = 1;
 365         tag_set.nr_maps = 1;
 366         tag_set.queue_depth = 16;
 367         tag_set.numa_node = NUMA_NO_NODE;
 368         tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
 369         ret = blk_mq_alloc_tag_set(&tag_set);
 370         if (ret)
 371                 goto out_unregister_blkdev;
 372
 373         for (i = 0; i < Z2MINOR_COUNT; i++) {
 374                 ret = z2ram_register_disk(i);
 375                 if (ret && i == 0)
 376                         goto out_free_tagset;
 377         }
 378
 379         return 0;
 380
 381 out_free_tagset:
 382         blk_mq_free_tag_set(&tag_set);
 383 out_unregister_blkdev:
 384         unregister_blkdev(Z2RAM_MAJOR, DEVICE_NAME);
 385         return ret;
 386 }
 387
 388 static void __exit z2_exit(void)
 389 {
 390         int i, j;
 391
 392         unregister_blkdev(Z2RAM_MAJOR, DEVICE_NAME);
 393
 394         for (i = 0; i < Z2MINOR_COUNT; i++) {
 395                 del_gendisk(z2ram_gendisk[i]);
 396                 blk_cleanup_queue(z2ram_gendisk[i]->queue);
 397                 put_disk(z2ram_gendisk[i]);
 398         }
 399         blk_mq_free_tag_set(&tag_set);
 400
 401         if (current_device != -1) {
 402                 i = 0;
 403
 404                 for (j = 0; j < z2_count; j++) {
 405                         set_bit(i++, zorro_unused_z2ram);
 406                 }
 407
 408                 for (j = 0; j < chip_count; j++) {
 409                         if (z2ram_map[i]) {
 410                                 amiga_chip_free((void *)z2ram_map[i++]);
 411                         }
 412                 }
 413
 414                 if (z2ram_map != NULL) {
 415                         kfree(z2ram_map);
 416                 }
 417         }
 418
 419         return;
 420 }
 421
 422 module_init(z2_init);
 423 module_exit(z2_exit);
 424 MODULE_LICENSE("GPL");