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alistair23-linux/drivers/block/z2ram.c
Christoph Hellwig 2a842acab1 block: introduce new block status code type 
Currently we use nornal Linux errno values in the block layer, and while
we accept any error a few have overloaded magic meanings.  This patch
instead introduces a new  blk_status_t value that holds block layer specific
status codes and explicitly explains their meaning.  Helpers to convert from
and to the previous special meanings are provided for now, but I suspect
we want to get rid of them in the long run - those drivers that have a
errno input (e.g. networking) usually get errnos that don't know about
the special block layer overloads, and similarly returning them to userspace
will usually return somethings that strictly speaking isn't correct
for file system operations, but that's left as an exercise for later.

For now the set of errors is a very limited set that closely corresponds
to the previous overloaded errno values, but there is some low hanging
fruite to improve it.

blk_status_t (ab)uses the sparse __bitwise annotations to allow for sparse
typechecking, so that we can easily catch places passing the wrong values.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-06-09 09:27:32 -06:00

419 lines
9.2 KiB
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/*
** z2ram - Amiga pseudo-driver to access 16bit-RAM in ZorroII space
** as a block device, to be used as a RAM disk or swap space
**
** Copyright (C) 1994 by Ingo Wilken (Ingo.Wilken@informatik.uni-oldenburg.de)
**
** ++Geert: support for zorro_unused_z2ram, better range checking
** ++roman: translate accesses via an array
** ++Milan: support for ChipRAM usage
** ++yambo: converted to 2.0 kernel
** ++yambo: modularized and support added for 3 minor devices including:
** MAJOR MINOR DESCRIPTION
** ----- ----- ----------------------------------------------
** 37 0 Use Zorro II and Chip ram
** 37 1 Use only Zorro II ram
** 37 2 Use only Chip ram
** 37 4-7 Use memory list entry 1-4 (first is 0)
** ++jskov: support for 1-4th memory list entry.
**
** Permission to use, copy, modify, and distribute this software and its
** documentation for any purpose and without fee is hereby granted, provided
** that the above copyright notice appear in all copies and that both that
** copyright notice and this permission notice appear in supporting
** documentation. This software is provided "as is" without express or
** implied warranty.
*/
#define DEVICE_NAME "Z2RAM"
#include <linux/major.h>
#include <linux/vmalloc.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/blkdev.h>
#include <linux/bitops.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <asm/setup.h>
#include <asm/amigahw.h>
#include <asm/pgtable.h>
#include <linux/zorro.h>
#define Z2MINOR_COMBINED (0)
#define Z2MINOR_Z2ONLY (1)
#define Z2MINOR_CHIPONLY (2)
#define Z2MINOR_MEMLIST1 (4)
#define Z2MINOR_MEMLIST2 (5)
#define Z2MINOR_MEMLIST3 (6)
#define Z2MINOR_MEMLIST4 (7)
#define Z2MINOR_COUNT (8) /* Move this down when adding a new minor */
#define Z2RAM_CHUNK1024 ( Z2RAM_CHUNKSIZE >> 10 )
static DEFINE_MUTEX(z2ram_mutex);
static u_long *z2ram_map = NULL;
static u_long z2ram_size = 0;
static int z2_count = 0;
static int chip_count = 0;
static int list_count = 0;
static int current_device = -1;
static DEFINE_SPINLOCK(z2ram_lock);
static struct gendisk *z2ram_gendisk;
static void do_z2_request(struct request_queue *q)
{
struct request *req;
req = blk_fetch_request(q);
while (req) {
unsigned long start = blk_rq_pos(req) << 9;
unsigned long len = blk_rq_cur_bytes(req);
blk_status_t err = BLK_STS_OK;
if (start + len > z2ram_size) {
pr_err(DEVICE_NAME ": bad access: block=%llu, "
"count=%u\n",
(unsigned long long)blk_rq_pos(req),
blk_rq_cur_sectors(req));
err = BLK_STS_IOERR;
goto done;
}
while (len) {
unsigned long addr = start & Z2RAM_CHUNKMASK;
unsigned long size = Z2RAM_CHUNKSIZE - addr;
void *buffer = bio_data(req->bio);
if (len < size)
size = len;
addr += z2ram_map[ start >> Z2RAM_CHUNKSHIFT ];
if (rq_data_dir(req) == READ)
memcpy(buffer, (char *)addr, size);
else
memcpy((char *)addr, buffer, size);
start += size;
len -= size;
}
done:
if (!__blk_end_request_cur(req, err))
req = blk_fetch_request(q);
}
}
static void
get_z2ram( void )
{
int i;
for ( i = 0; i < Z2RAM_SIZE / Z2RAM_CHUNKSIZE; i++ )
{
if ( test_bit( i, zorro_unused_z2ram ) )
{
z2_count++;
z2ram_map[z2ram_size++] = (unsigned long)ZTWO_VADDR(Z2RAM_START) +
(i << Z2RAM_CHUNKSHIFT);
clear_bit( i, zorro_unused_z2ram );
}
}
return;
}
static void
get_chipram( void )
{
while ( amiga_chip_avail() > ( Z2RAM_CHUNKSIZE * 4 ) )
{
chip_count++;
z2ram_map[ z2ram_size ] =
(u_long)amiga_chip_alloc( Z2RAM_CHUNKSIZE, "z2ram" );
if ( z2ram_map[ z2ram_size ] == 0 )
{
break;
}
z2ram_size++;
}
return;
}
static int z2_open(struct block_device *bdev, fmode_t mode)
{
int device;
int max_z2_map = ( Z2RAM_SIZE / Z2RAM_CHUNKSIZE ) *
sizeof( z2ram_map[0] );
int max_chip_map = ( amiga_chip_size / Z2RAM_CHUNKSIZE ) *
sizeof( z2ram_map[0] );
int rc = -ENOMEM;
device = MINOR(bdev->bd_dev);
mutex_lock(&z2ram_mutex);
if ( current_device != -1 && current_device != device )
{
rc = -EBUSY;
goto err_out;
}
if ( current_device == -1 )
{
z2_count = 0;
chip_count = 0;
list_count = 0;
z2ram_size = 0;
/* Use a specific list entry. */
if (device >= Z2MINOR_MEMLIST1 && device <= Z2MINOR_MEMLIST4) {
int index = device - Z2MINOR_MEMLIST1 + 1;
unsigned long size, paddr, vaddr;
if (index >= m68k_realnum_memory) {
printk( KERN_ERR DEVICE_NAME
": no such entry in z2ram_map\n" );
goto err_out;
}
paddr = m68k_memory[index].addr;
size = m68k_memory[index].size & ~(Z2RAM_CHUNKSIZE-1);
#ifdef __powerpc__
/* FIXME: ioremap doesn't build correct memory tables. */
{
vfree(vmalloc (size));
}
vaddr = (unsigned long) __ioremap (paddr, size,
_PAGE_WRITETHRU);
#else
vaddr = (unsigned long)z_remap_nocache_nonser(paddr, size);
#endif
z2ram_map =
kmalloc((size/Z2RAM_CHUNKSIZE)*sizeof(z2ram_map[0]),
GFP_KERNEL);
if ( z2ram_map == NULL )
{
printk( KERN_ERR DEVICE_NAME
": cannot get mem for z2ram_map\n" );
goto err_out;
}
while (size) {
z2ram_map[ z2ram_size++ ] = vaddr;
size -= Z2RAM_CHUNKSIZE;
vaddr += Z2RAM_CHUNKSIZE;
list_count++;
}
if ( z2ram_size != 0 )
printk( KERN_INFO DEVICE_NAME
": using %iK List Entry %d Memory\n",
list_count * Z2RAM_CHUNK1024, index );
} else
switch ( device )
{
case Z2MINOR_COMBINED:
z2ram_map = kmalloc( max_z2_map + max_chip_map, GFP_KERNEL );
if ( z2ram_map == NULL )
{
printk( KERN_ERR DEVICE_NAME
": cannot get mem for z2ram_map\n" );
goto err_out;
}
get_z2ram();
get_chipram();
if ( z2ram_size != 0 )
printk( KERN_INFO DEVICE_NAME
": using %iK Zorro II RAM and %iK Chip RAM (Total %dK)\n",
z2_count * Z2RAM_CHUNK1024,
chip_count * Z2RAM_CHUNK1024,
( z2_count + chip_count ) * Z2RAM_CHUNK1024 );
break;
case Z2MINOR_Z2ONLY:
z2ram_map = kmalloc( max_z2_map, GFP_KERNEL );
if ( z2ram_map == NULL )
{
printk( KERN_ERR DEVICE_NAME
": cannot get mem for z2ram_map\n" );
goto err_out;
}
get_z2ram();
if ( z2ram_size != 0 )
printk( KERN_INFO DEVICE_NAME
": using %iK of Zorro II RAM\n",
z2_count * Z2RAM_CHUNK1024 );
break;
case Z2MINOR_CHIPONLY:
z2ram_map = kmalloc( max_chip_map, GFP_KERNEL );
if ( z2ram_map == NULL )
{
printk( KERN_ERR DEVICE_NAME
": cannot get mem for z2ram_map\n" );
goto err_out;
}
get_chipram();
if ( z2ram_size != 0 )
printk( KERN_INFO DEVICE_NAME
": using %iK Chip RAM\n",
chip_count * Z2RAM_CHUNK1024 );
break;
default:
rc = -ENODEV;
goto err_out;
break;
}
if ( z2ram_size == 0 )
{
printk( KERN_NOTICE DEVICE_NAME
": no unused ZII/Chip RAM found\n" );
goto err_out_kfree;
}
current_device = device;
z2ram_size <<= Z2RAM_CHUNKSHIFT;
set_capacity(z2ram_gendisk, z2ram_size >> 9);
}
mutex_unlock(&z2ram_mutex);
return 0;
err_out_kfree:
kfree(z2ram_map);
err_out:
mutex_unlock(&z2ram_mutex);
return rc;
}
static void
z2_release(struct gendisk *disk, fmode_t mode)
{
mutex_lock(&z2ram_mutex);
if ( current_device == -1 ) {
mutex_unlock(&z2ram_mutex);
return;
}
mutex_unlock(&z2ram_mutex);
/*
* FIXME: unmap memory
*/
}
static const struct block_device_operations z2_fops =
{
.owner = THIS_MODULE,
.open = z2_open,
.release = z2_release,
};
static struct kobject *z2_find(dev_t dev, int *part, void *data)
{
*part = 0;
return get_disk(z2ram_gendisk);
}
static struct request_queue *z2_queue;
static int __init
z2_init(void)
{
int ret;
if (!MACH_IS_AMIGA)
return -ENODEV;
ret = -EBUSY;
if (register_blkdev(Z2RAM_MAJOR, DEVICE_NAME))
goto err;
ret = -ENOMEM;
z2ram_gendisk = alloc_disk(1);
if (!z2ram_gendisk)
goto out_disk;
z2_queue = blk_init_queue(do_z2_request, &z2ram_lock);
if (!z2_queue)
goto out_queue;
z2ram_gendisk->major = Z2RAM_MAJOR;
z2ram_gendisk->first_minor = 0;
z2ram_gendisk->fops = &z2_fops;
sprintf(z2ram_gendisk->disk_name, "z2ram");
z2ram_gendisk->queue = z2_queue;
add_disk(z2ram_gendisk);
blk_register_region(MKDEV(Z2RAM_MAJOR, 0), Z2MINOR_COUNT, THIS_MODULE,
z2_find, NULL, NULL);
return 0;
out_queue:
put_disk(z2ram_gendisk);
out_disk:
unregister_blkdev(Z2RAM_MAJOR, DEVICE_NAME);
err:
return ret;
}
static void __exit z2_exit(void)
{
int i, j;
blk_unregister_region(MKDEV(Z2RAM_MAJOR, 0), Z2MINOR_COUNT);
unregister_blkdev(Z2RAM_MAJOR, DEVICE_NAME);
del_gendisk(z2ram_gendisk);
put_disk(z2ram_gendisk);
blk_cleanup_queue(z2_queue);
if ( current_device != -1 )
{
i = 0;
for ( j = 0 ; j < z2_count; j++ )
{
set_bit( i++, zorro_unused_z2ram );
}
for ( j = 0 ; j < chip_count; j++ )
{
if ( z2ram_map[ i ] )
{
amiga_chip_free( (void *) z2ram_map[ i++ ] );
}
}
if ( z2ram_map != NULL )
{
kfree( z2ram_map );
}
}
return;
}
module_init(z2_init);
module_exit(z2_exit);
MODULE_LICENSE("GPL");
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