linux/drivers/block/z2ram.c
Tejun Heo 9934c8c045 block: implement and enforce request peek/start/fetch
Till now block layer allowed two separate modes of request execution.
A request is always acquired from the request queue via
elv_next_request().  After that, drivers are free to either dequeue it
or process it without dequeueing.  Dequeue allows elv_next_request()
to return the next request so that multiple requests can be in flight.

Executing requests without dequeueing has its merits mostly in
allowing drivers for simpler devices which can't do sg to deal with
segments only without considering request boundary.  However, the
benefit this brings is dubious and declining while the cost of the API
ambiguity is increasing.  Segment based drivers are usually for very
old or limited devices and as converting to dequeueing model isn't
difficult, it doesn't justify the API overhead it puts on block layer
and its more modern users.

Previous patches converted all block low level drivers to dequeueing
model.  This patch completes the API transition by...

* renaming elv_next_request() to blk_peek_request()

* renaming blkdev_dequeue_request() to blk_start_request()

* adding blk_fetch_request() which is combination of peek and start

* disallowing completion of queued (not started) requests

* applying new API to all LLDs

Renamings are for consistency and to break out of tree code so that
it's apparent that out of tree drivers need updating.

[ Impact: block request issue API cleanup, no functional change ]

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Mike Miller <mike.miller@hp.com>
Cc: unsik Kim <donari75@gmail.com>
Cc: Paul Clements <paul.clements@steeleye.com>
Cc: Tim Waugh <tim@cyberelk.net>
Cc: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Laurent Vivier <Laurent@lvivier.info>
Cc: Jeff Garzik <jgarzik@pobox.com>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Adrian McMenamin <adrian@mcmen.demon.co.uk>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Cc: Borislav Petkov <petkovbb@googlemail.com>
Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Cc: Alex Dubov <oakad@yahoo.com>
Cc: Pierre Ossman <drzeus@drzeus.cx>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Markus Lidel <Markus.Lidel@shadowconnect.com>
Cc: Stefan Weinhuber <wein@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Pete Zaitcev <zaitcev@redhat.com>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-05-11 09:52:18 +02:00

411 lines
8.9 KiB
C

/*
** 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 <asm/setup.h>
#include <asm/amigahw.h>
#include <asm/pgtable.h>
#include <linux/zorro.h>
extern int m68k_realnum_memory;
extern struct mem_info m68k_memory[NUM_MEMINFO];
#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 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 block_device_operations z2_fops;
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);
int err = 0;
if (start + len > z2ram_size) {
printk( KERN_ERR DEVICE_NAME ": bad access: block=%lu, count=%u\n",
blk_rq_pos(req), blk_rq_cur_sectors(req));
err = -EIO;
goto done;
}
while (len) {
unsigned long addr = start & Z2RAM_CHUNKMASK;
unsigned long size = Z2RAM_CHUNKSIZE - addr;
if (len < size)
size = len;
addr += z2ram_map[ start >> Z2RAM_CHUNKSHIFT ];
if (rq_data_dir(req) == READ)
memcpy(req->buffer, (char *)addr, size);
else
memcpy((char *)addr, req->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++ ] =
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);
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);
}
return 0;
err_out_kfree:
kfree(z2ram_map);
err_out:
return rc;
}
static int
z2_release(struct gendisk *disk, fmode_t mode)
{
if ( current_device == -1 )
return 0;
/*
* FIXME: unmap memory
*/
return 0;
}
static 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), 256);
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");