linux/drivers/block/z2ram.c
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   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
  57static DEFINE_MUTEX(z2ram_mutex);
  58static u_long *z2ram_map    = NULL;
  59static u_long z2ram_size    = 0;
  60static int z2_count         = 0;
  61static int chip_count       = 0;
  62static int list_count       = 0;
  63static int current_device   = -1;
  64
  65static DEFINE_SPINLOCK(z2ram_lock);
  66
  67static struct gendisk *z2ram_gendisk;
  68
  69static 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
 109static void
 110get_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
 128static void
 129get_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
 149static 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 (paddr, size, 
 195                                                   _PAGE_WRITETHRU);
 196
 197#else
 198                vaddr = (unsigned long)z_remap_nocache_nonser(paddr, size);
 199#endif
 200                z2ram_map = 
 201                        kmalloc_array(size / Z2RAM_CHUNKSIZE,
 202                                      sizeof(z2ram_map[0]),
 203                                      GFP_KERNEL);
 204                if ( z2ram_map == NULL )
 205                {
 206                    printk( KERN_ERR DEVICE_NAME
 207                        ": cannot get mem for z2ram_map\n" );
 208                    goto err_out;
 209                }
 210
 211                while (size) {
 212                        z2ram_map[ z2ram_size++ ] = vaddr;
 213                        size -= Z2RAM_CHUNKSIZE;
 214                        vaddr += Z2RAM_CHUNKSIZE;
 215                        list_count++;
 216                }
 217
 218                if ( z2ram_size != 0 )
 219                    printk( KERN_INFO DEVICE_NAME
 220                        ": using %iK List Entry %d Memory\n",
 221                        list_count * Z2RAM_CHUNK1024, index );
 222        } else
 223
 224        switch ( device )
 225        {
 226            case Z2MINOR_COMBINED:
 227
 228                z2ram_map = kmalloc( max_z2_map + max_chip_map, GFP_KERNEL );
 229                if ( z2ram_map == NULL )
 230                {
 231                    printk( KERN_ERR DEVICE_NAME
 232                        ": cannot get mem for z2ram_map\n" );
 233                    goto err_out;
 234                }
 235
 236                get_z2ram();
 237                get_chipram();
 238
 239                if ( z2ram_size != 0 )
 240                    printk( KERN_INFO DEVICE_NAME 
 241                        ": using %iK Zorro II RAM and %iK Chip RAM (Total %dK)\n",
 242                        z2_count * Z2RAM_CHUNK1024,
 243                        chip_count * Z2RAM_CHUNK1024,
 244                        ( z2_count + chip_count ) * Z2RAM_CHUNK1024 );
 245
 246            break;
 247
 248            case Z2MINOR_Z2ONLY:
 249                z2ram_map = kmalloc( max_z2_map, GFP_KERNEL );
 250                if ( z2ram_map == NULL )
 251                {
 252                    printk( KERN_ERR DEVICE_NAME
 253                        ": cannot get mem for z2ram_map\n" );
 254                    goto err_out;
 255                }
 256
 257                get_z2ram();
 258
 259                if ( z2ram_size != 0 )
 260                    printk( KERN_INFO DEVICE_NAME 
 261                        ": using %iK of Zorro II RAM\n",
 262                        z2_count * Z2RAM_CHUNK1024 );
 263
 264            break;
 265
 266            case Z2MINOR_CHIPONLY:
 267                z2ram_map = kmalloc( max_chip_map, GFP_KERNEL );
 268                if ( z2ram_map == NULL )
 269                {
 270                    printk( KERN_ERR DEVICE_NAME
 271                        ": cannot get mem for z2ram_map\n" );
 272                    goto err_out;
 273                }
 274
 275                get_chipram();
 276
 277                if ( z2ram_size != 0 )
 278                    printk( KERN_INFO DEVICE_NAME 
 279                        ": using %iK Chip RAM\n",
 280                        chip_count * Z2RAM_CHUNK1024 );
 281                    
 282            break;
 283
 284            default:
 285                rc = -ENODEV;
 286                goto err_out;
 287        
 288            break;
 289        }
 290
 291        if ( z2ram_size == 0 )
 292        {
 293            printk( KERN_NOTICE DEVICE_NAME
 294                ": no unused ZII/Chip RAM found\n" );
 295            goto err_out_kfree;
 296        }
 297
 298        current_device = device;
 299        z2ram_size <<= Z2RAM_CHUNKSHIFT;
 300        set_capacity(z2ram_gendisk, z2ram_size >> 9);
 301    }
 302
 303    mutex_unlock(&z2ram_mutex);
 304    return 0;
 305
 306err_out_kfree:
 307    kfree(z2ram_map);
 308err_out:
 309    mutex_unlock(&z2ram_mutex);
 310    return rc;
 311}
 312
 313static void
 314z2_release(struct gendisk *disk, fmode_t mode)
 315{
 316    mutex_lock(&z2ram_mutex);
 317    if ( current_device == -1 ) {
 318        mutex_unlock(&z2ram_mutex);
 319        return;
 320    }
 321    mutex_unlock(&z2ram_mutex);
 322    /*
 323     * FIXME: unmap memory
 324     */
 325}
 326
 327static const struct block_device_operations z2_fops =
 328{
 329        .owner          = THIS_MODULE,
 330        .open           = z2_open,
 331        .release        = z2_release,
 332};
 333
 334static struct kobject *z2_find(dev_t dev, int *part, void *data)
 335{
 336        *part = 0;
 337        return get_disk_and_module(z2ram_gendisk);
 338}
 339
 340static struct request_queue *z2_queue;
 341static struct blk_mq_tag_set tag_set;
 342
 343static const struct blk_mq_ops z2_mq_ops = {
 344        .queue_rq       = z2_queue_rq,
 345};
 346
 347static int __init 
 348z2_init(void)
 349{
 350    int ret;
 351
 352    if (!MACH_IS_AMIGA)
 353        return -ENODEV;
 354
 355    ret = -EBUSY;
 356    if (register_blkdev(Z2RAM_MAJOR, DEVICE_NAME))
 357        goto err;
 358
 359    ret = -ENOMEM;
 360    z2ram_gendisk = alloc_disk(1);
 361    if (!z2ram_gendisk)
 362        goto out_disk;
 363
 364    z2_queue = blk_mq_init_sq_queue(&tag_set, &z2_mq_ops, 16,
 365                                        BLK_MQ_F_SHOULD_MERGE);
 366    if (IS_ERR(z2_queue)) {
 367        ret = PTR_ERR(z2_queue);
 368        z2_queue = NULL;
 369        goto out_queue;
 370    }
 371
 372    z2ram_gendisk->major = Z2RAM_MAJOR;
 373    z2ram_gendisk->first_minor = 0;
 374    z2ram_gendisk->fops = &z2_fops;
 375    sprintf(z2ram_gendisk->disk_name, "z2ram");
 376
 377    z2ram_gendisk->queue = z2_queue;
 378    add_disk(z2ram_gendisk);
 379    blk_register_region(MKDEV(Z2RAM_MAJOR, 0), Z2MINOR_COUNT, THIS_MODULE,
 380                                z2_find, NULL, NULL);
 381
 382    return 0;
 383
 384out_queue:
 385    put_disk(z2ram_gendisk);
 386out_disk:
 387    unregister_blkdev(Z2RAM_MAJOR, DEVICE_NAME);
 388err:
 389    return ret;
 390}
 391
 392static void __exit z2_exit(void)
 393{
 394    int i, j;
 395    blk_unregister_region(MKDEV(Z2RAM_MAJOR, 0), Z2MINOR_COUNT);
 396    unregister_blkdev(Z2RAM_MAJOR, DEVICE_NAME);
 397    del_gendisk(z2ram_gendisk);
 398    put_disk(z2ram_gendisk);
 399    blk_cleanup_queue(z2_queue);
 400    blk_mq_free_tag_set(&tag_set);
 401
 402    if ( current_device != -1 )
 403    {
 404        i = 0;
 405
 406        for ( j = 0 ; j < z2_count; j++ )
 407        {
 408            set_bit( i++, zorro_unused_z2ram ); 
 409        }
 410
 411        for ( j = 0 ; j < chip_count; j++ )
 412        {
 413            if ( z2ram_map[ i ] )
 414            {
 415                amiga_chip_free( (void *) z2ram_map[ i++ ] );
 416            }
 417        }
 418
 419        if ( z2ram_map != NULL )
 420        {
 421            kfree( z2ram_map );
 422        }
 423    }
 424
 425    return;
 426} 
 427
 428module_init(z2_init);
 429module_exit(z2_exit);
 430MODULE_LICENSE("GPL");
 431