[linux-2.6-block.git] / drivers / s390 / block / xpram.c

/*
 * Xpram.c -- the S/390 expanded memory RAM-disk
 *           
 * significant parts of this code are based on
 * the sbull device driver presented in
 * A. Rubini: Linux Device Drivers
 *
 * Author of XPRAM specific coding: Reinhard Buendgen
 *                                  buendgen@de.ibm.com
 * Rewrite for 2.5: Martin Schwidefsky <schwidefsky@de.ibm.com>
 *
 * External interfaces:
 *   Interfaces to linux kernel
 *        xpram_setup: read kernel parameters
 *   Device specific file operations
 *        xpram_iotcl
 *        xpram_open
 *
 * "ad-hoc" partitioning:
 *    the expanded memory can be partitioned among several devices 
 *    (with different minors). The partitioning set up can be
 *    set by kernel or module parameters (int devs & int sizes[])
 *
 * Potential future improvements:
 *   generic hard disk support to replace ad-hoc partitioning
 */

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/ctype.h>  /* isdigit, isxdigit */
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/blkdev.h>
#include <linux/blkpg.h>
#include <linux/hdreg.h>  /* HDIO_GETGEO */
#include <linux/sysdev.h>
#include <linux/bio.h>
#include <asm/uaccess.h>

#define XPRAM_NAME	"xpram"
#define XPRAM_DEVS	1	/* one partition */
#define XPRAM_MAX_DEVS	32	/* maximal number of devices (partitions) */

#define PRINT_DEBUG(x...)	printk(KERN_DEBUG XPRAM_NAME " debug:" x)
#define PRINT_INFO(x...)	printk(KERN_INFO XPRAM_NAME " info:" x)
#define PRINT_WARN(x...)	printk(KERN_WARNING XPRAM_NAME " warning:" x)
#define PRINT_ERR(x...)		printk(KERN_ERR XPRAM_NAME " error:" x)


typedef struct {
	unsigned int	size;		/* size of xpram segment in pages */
	unsigned int	offset;		/* start page of xpram segment */
} xpram_device_t;

static xpram_device_t xpram_devices[XPRAM_MAX_DEVS];
static unsigned int xpram_sizes[XPRAM_MAX_DEVS];
static struct gendisk *xpram_disks[XPRAM_MAX_DEVS];
static unsigned int xpram_pages;
static int xpram_devs;

/*
 * Parameter parsing functions.
 */
static int __initdata devs = XPRAM_DEVS;
static char __initdata *sizes[XPRAM_MAX_DEVS];

module_param(devs, int, 0);
module_param_array(sizes, charp, NULL, 0);

MODULE_PARM_DESC(devs, "number of devices (\"partitions\"), " \
		 "the default is " __MODULE_STRING(XPRAM_DEVS) "\n");
MODULE_PARM_DESC(sizes, "list of device (partition) sizes " \
		 "the defaults are 0s \n" \
		 "All devices with size 0 equally partition the "
		 "remaining space on the expanded strorage not "
		 "claimed by explicit sizes\n");
MODULE_LICENSE("GPL");

/*
 * Copy expanded memory page (4kB) into main memory                  
 * Arguments                                                         
 *           page_addr:    address of target page                    
 *           xpage_index:  index of expandeded memory page           
 * Return value                                                      
 *           0:            if operation succeeds
 *           -EIO:         if pgin failed
 *           -ENXIO:       if xpram has vanished
 */
static int xpram_page_in (unsigned long page_addr, unsigned int xpage_index)
{
	int cc = 2;	/* return unused cc 2 if pgin traps */

	asm volatile(
		"	.insn	rre,0xb22e0000,%1,%2\n"  /* pgin %1,%2 */
		"0:	ipm	%0\n"
		"	srl	%0,28\n"
		"1:\n"
		EX_TABLE(0b,1b)
		: "+d" (cc) : "a" (__pa(page_addr)), "d" (xpage_index) : "cc");
	if (cc == 3)
		return -ENXIO;
	if (cc == 2) {
		PRINT_ERR("expanded storage lost!\n");
		return -ENXIO;
	}
	if (cc == 1) {
		PRINT_ERR("page in failed for page index %u.\n",
			  xpage_index);
		return -EIO;
	}
	return 0;
}

/*
 * Copy a 4kB page of main memory to an expanded memory page          
 * Arguments                                                          
 *           page_addr:    address of source page                     
 *           xpage_index:  index of expandeded memory page            
 * Return value                                                       
 *           0:            if operation succeeds
 *           -EIO:         if pgout failed
 *           -ENXIO:       if xpram has vanished
 */
static long xpram_page_out (unsigned long page_addr, unsigned int xpage_index)
{
	int cc = 2;	/* return unused cc 2 if pgin traps */

	asm volatile(
		"	.insn	rre,0xb22f0000,%1,%2\n"  /* pgout %1,%2 */
		"0:	ipm	%0\n"
		"	srl	%0,28\n"
		"1:\n"
		EX_TABLE(0b,1b)
		: "+d" (cc) : "a" (__pa(page_addr)), "d" (xpage_index) : "cc");
	if (cc == 3)
		return -ENXIO;
	if (cc == 2) {
		PRINT_ERR("expanded storage lost!\n");
		return -ENXIO;
	}
	if (cc == 1) {
		PRINT_ERR("page out failed for page index %u.\n",
			  xpage_index);
		return -EIO;
	}
	return 0;
}

/*
 * Check if xpram is available.
 */
static int __init xpram_present(void)
{
	unsigned long mem_page;
	int rc;

	mem_page = (unsigned long) __get_free_page(GFP_KERNEL);
	if (!mem_page)
		return -ENOMEM;
	rc = xpram_page_in(mem_page, 0);
	free_page(mem_page);
	return rc ? -ENXIO : 0;
}

/*
 * Return index of the last available xpram page.
 */
static unsigned long __init xpram_highest_page_index(void)
{
	unsigned int page_index, add_bit;
	unsigned long mem_page;

	mem_page = (unsigned long) __get_free_page(GFP_KERNEL);
	if (!mem_page)
		return 0;

	page_index = 0;
	add_bit = 1ULL << (sizeof(unsigned int)*8 - 1);
	while (add_bit > 0) {
		if (xpram_page_in(mem_page, page_index | add_bit) == 0)
			page_index |= add_bit;
		add_bit >>= 1;
	}

	free_page (mem_page);

	return page_index;
}

/*
 * Block device make request function.
 */
static int xpram_make_request(struct request_queue *q, struct bio *bio)
{
	xpram_device_t *xdev = bio->bi_bdev->bd_disk->private_data;
	struct bio_vec *bvec;
	unsigned int index;
	unsigned long page_addr;
	unsigned long bytes;
	int i;

	if ((bio->bi_sector & 7) != 0 || (bio->bi_size & 4095) != 0)
		/* Request is not page-aligned. */
		goto fail;
	if ((bio->bi_size >> 12) > xdev->size)
		/* Request size is no page-aligned. */
		goto fail;
	if ((bio->bi_sector >> 3) > 0xffffffffU - xdev->offset)
		goto fail;
	index = (bio->bi_sector >> 3) + xdev->offset;
	bio_for_each_segment(bvec, bio, i) {
		page_addr = (unsigned long)
			kmap(bvec->bv_page) + bvec->bv_offset;
		bytes = bvec->bv_len;
		if ((page_addr & 4095) != 0 || (bytes & 4095) != 0)
			/* More paranoia. */
			goto fail;
		while (bytes > 0) {
			if (bio_data_dir(bio) == READ) {
				if (xpram_page_in(page_addr, index) != 0)
					goto fail;
			} else {
				if (xpram_page_out(page_addr, index) != 0)
					goto fail;
			}
			page_addr += 4096;
			bytes -= 4096;
			index++;
		}
	}
	set_bit(BIO_UPTODATE, &bio->bi_flags);
	bio_end_io(bio, 0);
	return 0;
fail:
	bio_io_error(bio);
	return 0;
}

static int xpram_getgeo(struct block_device *bdev, struct hd_geometry *geo)
{
	unsigned long size;

	/*
	 * get geometry: we have to fake one...  trim the size to a
	 * multiple of 64 (32k): tell we have 16 sectors, 4 heads,
	 * whatever cylinders. Tell also that data starts at sector. 4.
	 */
	size = (xpram_pages * 8) & ~0x3f;
	geo->cylinders = size >> 6;
	geo->heads = 4;
	geo->sectors = 16;
	geo->start = 4;
	return 0;
}

static struct block_device_operations xpram_devops =
{
	.owner	= THIS_MODULE,
	.getgeo	= xpram_getgeo,
};

/*
 * Setup xpram_sizes array.
 */
static int __init xpram_setup_sizes(unsigned long pages)
{
	unsigned long mem_needed;
	unsigned long mem_auto;
	unsigned long long size;
	int mem_auto_no;
	int i;

	/* Check number of devices. */
	if (devs <= 0 || devs > XPRAM_MAX_DEVS) {
		PRINT_ERR("invalid number %d of devices\n",devs);
		return -EINVAL;
	}
	xpram_devs = devs;

	/*
	 * Copy sizes array to xpram_sizes and align partition
	 * sizes to page boundary.
	 */
	mem_needed = 0;
	mem_auto_no = 0;
	for (i = 0; i < xpram_devs; i++) {
		if (sizes[i]) {
			size = simple_strtoull(sizes[i], &sizes[i], 0);
			switch (sizes[i][0]) {
			case 'g':
			case 'G':
				size <<= 20;
				break;
			case 'm':
			case 'M':
				size <<= 10;
			}
			xpram_sizes[i] = (size + 3) & -4UL;
		}
		if (xpram_sizes[i])
			mem_needed += xpram_sizes[i];
		else
			mem_auto_no++;
	}
	
	PRINT_INFO("  number of devices (partitions): %d \n", xpram_devs);
	for (i = 0; i < xpram_devs; i++) {
		if (xpram_sizes[i])
			PRINT_INFO("  size of partition %d: %u kB\n",
				   i, xpram_sizes[i]);
		else
			PRINT_INFO("  size of partition %d to be set "
				   "automatically\n",i);
	}
	PRINT_DEBUG("  memory needed (for sized partitions): %lu kB\n",
		    mem_needed);
	PRINT_DEBUG("  partitions to be sized automatically: %d\n",
		    mem_auto_no);

	if (mem_needed > pages * 4) {
		PRINT_ERR("Not enough expanded memory available\n");
		return -EINVAL;
	}

	/*
	 * partitioning:
	 * xpram_sizes[i] != 0; partition i has size xpram_sizes[i] kB
	 * else:             ; all partitions with zero xpram_sizes[i]
	 *                     partition equally the remaining space
	 */
	if (mem_auto_no) {
		mem_auto = ((pages - mem_needed / 4) / mem_auto_no) * 4;
		PRINT_INFO("  automatically determined "
			   "partition size: %lu kB\n", mem_auto);
		for (i = 0; i < xpram_devs; i++)
			if (xpram_sizes[i] == 0)
				xpram_sizes[i] = mem_auto;
	}
	return 0;
}

static struct request_queue *xpram_queue;

static int __init xpram_setup_blkdev(void)
{
	unsigned long offset;
	int i, rc = -ENOMEM;

	for (i = 0; i < xpram_devs; i++) {
		struct gendisk *disk = alloc_disk(1);
		if (!disk)
			goto out;
		xpram_disks[i] = disk;
	}

	/*
	 * Register xpram major.
	 */
	rc = register_blkdev(XPRAM_MAJOR, XPRAM_NAME);
	if (rc < 0)
		goto out;

	/*
	 * Assign the other needed values: make request function, sizes and
	 * hardsect size. All the minor devices feature the same value.
	 */
	xpram_queue = blk_alloc_queue(GFP_KERNEL);
	if (!xpram_queue) {
		rc = -ENOMEM;
		goto out_unreg;
	}
	blk_queue_make_request(xpram_queue, xpram_make_request);
	blk_queue_hardsect_size(xpram_queue, 4096);

	/*
	 * Setup device structures.
	 */
	offset = 0;
	for (i = 0; i < xpram_devs; i++) {
		struct gendisk *disk = xpram_disks[i];

		xpram_devices[i].size = xpram_sizes[i] / 4;
		xpram_devices[i].offset = offset;
		offset += xpram_devices[i].size;
		disk->major = XPRAM_MAJOR;
		disk->first_minor = i;
		disk->fops = &xpram_devops;
		disk->private_data = &xpram_devices[i];
		disk->queue = xpram_queue;
		sprintf(disk->disk_name, "slram%d", i);
		set_capacity(disk, xpram_sizes[i] << 1);
		add_disk(disk);
	}

	return 0;
out_unreg:
	unregister_blkdev(XPRAM_MAJOR, XPRAM_NAME);
out:
	while (i--)
		put_disk(xpram_disks[i]);
	return rc;
}

/*
 * Finally, the init/exit functions.
 */
static void __exit xpram_exit(void)
{
	int i;
	for (i = 0; i < xpram_devs; i++) {
		del_gendisk(xpram_disks[i]);
		put_disk(xpram_disks[i]);
	}
	unregister_blkdev(XPRAM_MAJOR, XPRAM_NAME);
	blk_cleanup_queue(xpram_queue);
}

static int __init xpram_init(void)
{
	int rc;

	/* Find out size of expanded memory. */
	if (xpram_present() != 0) {
		PRINT_WARN("No expanded memory available\n");
		return -ENODEV;
	}
	xpram_pages = xpram_highest_page_index() + 1;
	PRINT_INFO("  %u pages expanded memory found (%lu KB).\n",
		   xpram_pages, (unsigned long) xpram_pages*4);
	rc = xpram_setup_sizes(xpram_pages);
	if (rc)
		return rc;
	return xpram_setup_blkdev();
}

module_init(xpram_init);
module_exit(xpram_exit);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Xpram.c -- the S/390 expanded memory RAM-disk
	3	*
	4	* significant parts of this code are based on
	5	* the sbull device driver presented in
	6	* A. Rubini: Linux Device Drivers
	7	*
	8	* Author of XPRAM specific coding: Reinhard Buendgen
	9	* buendgen@de.ibm.com
	10	* Rewrite for 2.5: Martin Schwidefsky <schwidefsky@de.ibm.com>
	11	*
	12	* External interfaces:
	13	* Interfaces to linux kernel
	14	* xpram_setup: read kernel parameters
	15	* Device specific file operations
	16	* xpram_iotcl
	17	* xpram_open
	18	*
	19	* "ad-hoc" partitioning:
	20	* the expanded memory can be partitioned among several devices
	21	* (with different minors). The partitioning set up can be
	22	* set by kernel or module parameters (int devs & int sizes[])
	23	*
	24	* Potential future improvements:
	25	* generic hard disk support to replace ad-hoc partitioning
	26	*/
	27
	28	#include <linux/module.h>
	29	#include <linux/moduleparam.h>
	30	#include <linux/ctype.h> /* isdigit, isxdigit */
	31	#include <linux/errno.h>
	32	#include <linux/init.h>
	33	#include <linux/slab.h>
	34	#include <linux/blkdev.h>
	35	#include <linux/blkpg.h>
	36	#include <linux/hdreg.h> /* HDIO_GETGEO */
	37	#include <linux/sysdev.h>
	38	#include <linux/bio.h>
1da177e4 LT	39	#include <asm/uaccess.h>
	40
	41	#define XPRAM_NAME "xpram"
	42	#define XPRAM_DEVS 1 /* one partition */
	43	#define XPRAM_MAX_DEVS 32 /* maximal number of devices (partitions) */
	44
	45	#define PRINT_DEBUG(x...) printk(KERN_DEBUG XPRAM_NAME " debug:" x)
	46	#define PRINT_INFO(x...) printk(KERN_INFO XPRAM_NAME " info:" x)
	47	#define PRINT_WARN(x...) printk(KERN_WARNING XPRAM_NAME " warning:" x)
	48	#define PRINT_ERR(x...) printk(KERN_ERR XPRAM_NAME " error:" x)
	49
	50
1da177e4 LT	51	typedef struct {
	52	unsigned int size; /* size of xpram segment in pages */
	53	unsigned int offset; /* start page of xpram segment */
	54	} xpram_device_t;
	55
	56	static xpram_device_t xpram_devices[XPRAM_MAX_DEVS];
	57	static unsigned int xpram_sizes[XPRAM_MAX_DEVS];
	58	static struct gendisk *xpram_disks[XPRAM_MAX_DEVS];
	59	static unsigned int xpram_pages;
	60	static int xpram_devs;
	61
	62	/*
	63	* Parameter parsing functions.
	64	*/
5c898ba9 HC	65	static int __initdata devs = XPRAM_DEVS;
5c898ba9 HC	66	static char __initdata *sizes[XPRAM_MAX_DEVS];
1da177e4 LT	67
1da177e4 LT	68	module_param(devs, int, 0);
5c898ba9	69	module_param_array(sizes, charp, NULL, 0);
1da177e4 LT	70
	71	MODULE_PARM_DESC(devs, "number of devices (\"partitions\"), " \
	72	"the default is " __MODULE_STRING(XPRAM_DEVS) "\n");
	73	MODULE_PARM_DESC(sizes, "list of device (partition) sizes " \
	74	"the defaults are 0s \n" \
	75	"All devices with size 0 equally partition the "
	76	"remaining space on the expanded strorage not "
	77	"claimed by explicit sizes\n");
	78	MODULE_LICENSE("GPL");
	79
1da177e4 LT	80	/*
	81	* Copy expanded memory page (4kB) into main memory
	82	* Arguments
	83	* page_addr: address of target page
	84	* xpage_index: index of expandeded memory page
	85	* Return value
	86	* 0: if operation succeeds
	87	* -EIO: if pgin failed
	88	* -ENXIO: if xpram has vanished
	89	*/
	90	static int xpram_page_in (unsigned long page_addr, unsigned int xpage_index)
	91	{
94c12cc7	92	int cc = 2; /* return unused cc 2 if pgin traps */
1da177e4	93
94c12cc7 MS	94	asm volatile(
	95	" .insn rre,0xb22e0000,%1,%2\n" /* pgin %1,%2 */
	96	"0: ipm %0\n"
	97	" srl %0,28\n"
1da177e4	98	"1:\n"
94c12cc7 MS	99	EX_TABLE(0b,1b)
94c12cc7 MS	100	: "+d" (cc) : "a" (__pa(page_addr)), "d" (xpage_index) : "cc");
1da177e4 LT	101	if (cc == 3)
	102	return -ENXIO;
	103	if (cc == 2) {
	104	PRINT_ERR("expanded storage lost!\n");
	105	return -ENXIO;
	106	}
	107	if (cc == 1) {
	108	PRINT_ERR("page in failed for page index %u.\n",
	109	xpage_index);
	110	return -EIO;
	111	}
	112	return 0;
	113	}
	114
	115	/*
	116	* Copy a 4kB page of main memory to an expanded memory page
	117	* Arguments
	118	* page_addr: address of source page
	119	* xpage_index: index of expandeded memory page
	120	* Return value
	121	* 0: if operation succeeds
	122	* -EIO: if pgout failed
	123	* -ENXIO: if xpram has vanished
	124	*/
	125	static long xpram_page_out (unsigned long page_addr, unsigned int xpage_index)
	126	{
94c12cc7	127	int cc = 2; /* return unused cc 2 if pgin traps */
1da177e4	128
94c12cc7 MS	129	asm volatile(
	130	" .insn rre,0xb22f0000,%1,%2\n" /* pgout %1,%2 */
	131	"0: ipm %0\n"
	132	" srl %0,28\n"
1da177e4	133	"1:\n"
94c12cc7 MS	134	EX_TABLE(0b,1b)
94c12cc7 MS	135	: "+d" (cc) : "a" (__pa(page_addr)), "d" (xpage_index) : "cc");
1da177e4 LT	136	if (cc == 3)
	137	return -ENXIO;
	138	if (cc == 2) {
	139	PRINT_ERR("expanded storage lost!\n");
	140	return -ENXIO;
	141	}
	142	if (cc == 1) {
	143	PRINT_ERR("page out failed for page index %u.\n",
	144	xpage_index);
	145	return -EIO;
	146	}
	147	return 0;
	148	}
	149
	150	/*
	151	* Check if xpram is available.
	152	*/
	153	static int __init xpram_present(void)
	154	{
	155	unsigned long mem_page;
	156	int rc;
	157
	158	mem_page = (unsigned long) __get_free_page(GFP_KERNEL);
	159	if (!mem_page)
	160	return -ENOMEM;
	161	rc = xpram_page_in(mem_page, 0);
	162	free_page(mem_page);
	163	return rc ? -ENXIO : 0;
	164	}
	165
	166	/*
	167	* Return index of the last available xpram page.
	168	*/
	169	static unsigned long __init xpram_highest_page_index(void)
	170	{
	171	unsigned int page_index, add_bit;
	172	unsigned long mem_page;
	173
	174	mem_page = (unsigned long) __get_free_page(GFP_KERNEL);
	175	if (!mem_page)
	176	return 0;
	177
	178	page_index = 0;
	179	add_bit = 1ULL << (sizeof(unsigned int)*8 - 1);
	180	while (add_bit > 0) {
	181	if (xpram_page_in(mem_page, page_index \| add_bit) == 0)
	182	page_index \|= add_bit;
	183	add_bit >>= 1;
	184	}
	185
	186	free_page (mem_page);
	187
	188	return page_index;
	189	}
	190
	191	/*
	192	* Block device make request function.
	193	*/
165125e1	194	static int xpram_make_request(struct request_queue q, struct bio bio)
1da177e4 LT	195	{
	196	xpram_device_t *xdev = bio->bi_bdev->bd_disk->private_data;
	197	struct bio_vec *bvec;
	198	unsigned int index;
	199	unsigned long page_addr;
	200	unsigned long bytes;
	201	int i;
	202
	203	if ((bio->bi_sector & 7) != 0 \|\| (bio->bi_size & 4095) != 0)
	204	/* Request is not page-aligned. */
	205	goto fail;
	206	if ((bio->bi_size >> 12) > xdev->size)
	207	/* Request size is no page-aligned. */
	208	goto fail;
	209	if ((bio->bi_sector >> 3) > 0xffffffffU - xdev->offset)
	210	goto fail;
	211	index = (bio->bi_sector >> 3) + xdev->offset;
	212	bio_for_each_segment(bvec, bio, i) {
	213	page_addr = (unsigned long)
	214	kmap(bvec->bv_page) + bvec->bv_offset;
	215	bytes = bvec->bv_len;
	216	if ((page_addr & 4095) != 0 \|\| (bytes & 4095) != 0)
	217	/* More paranoia. */
	218	goto fail;
	219	while (bytes > 0) {
	220	if (bio_data_dir(bio) == READ) {
	221	if (xpram_page_in(page_addr, index) != 0)
	222	goto fail;
	223	} else {
	224	if (xpram_page_out(page_addr, index) != 0)
	225	goto fail;
	226	}
	227	page_addr += 4096;
	228	bytes -= 4096;
	229	index++;
	230	}
	231	}
	232	set_bit(BIO_UPTODATE, &bio->bi_flags);
6712ecf8	233	bio_end_io(bio, 0);
1da177e4 LT	234	return 0;
1da177e4 LT	235	fail:
6712ecf8	236	bio_io_error(bio);
1da177e4 LT	237	return 0;
	238	}
	239
a885c8c4	240	static int xpram_getgeo(struct block_device bdev, struct hd_geometry geo)
1da177e4	241	{
1da177e4	242	unsigned long size;
a885c8c4	243
1da177e4 LT	244	/*
	245	* get geometry: we have to fake one... trim the size to a
	246	* multiple of 64 (32k): tell we have 16 sectors, 4 heads,
	247	* whatever cylinders. Tell also that data starts at sector. 4.
	248	*/
1da177e4	249	size = (xpram_pages * 8) & ~0x3f;
a885c8c4 CH	250	geo->cylinders = size >> 6;
	251	geo->heads = 4;
	252	geo->sectors = 16;
	253	geo->start = 4;
1da177e4 LT	254	return 0;
	255	}
	256
	257	static struct block_device_operations xpram_devops =
	258	{
	259	.owner = THIS_MODULE,
a885c8c4	260	.getgeo = xpram_getgeo,
1da177e4 LT	261	};
	262
	263	/*
	264	* Setup xpram_sizes array.
	265	*/
	266	static int __init xpram_setup_sizes(unsigned long pages)
	267	{
	268	unsigned long mem_needed;
	269	unsigned long mem_auto;
f257b063	270	unsigned long long size;
1da177e4 LT	271	int mem_auto_no;
	272	int i;
	273
	274	/* Check number of devices. */
	275	if (devs <= 0 \|\| devs > XPRAM_MAX_DEVS) {
	276	PRINT_ERR("invalid number %d of devices\n",devs);
	277	return -EINVAL;
	278	}
	279	xpram_devs = devs;
	280
	281	/*
	282	* Copy sizes array to xpram_sizes and align partition
	283	* sizes to page boundary.
	284	*/
	285	mem_needed = 0;
	286	mem_auto_no = 0;
	287	for (i = 0; i < xpram_devs; i++) {
f257b063 HC	288	if (sizes[i]) {
	289	size = simple_strtoull(sizes[i], &sizes[i], 0);
	290	switch (sizes[i][0]) {
	291	case 'g':
	292	case 'G':
	293	size <<= 20;
	294	break;
	295	case 'm':
	296	case 'M':
	297	size <<= 10;
	298	}
	299	xpram_sizes[i] = (size + 3) & -4UL;
	300	}
1da177e4 LT	301	if (xpram_sizes[i])
	302	mem_needed += xpram_sizes[i];
	303	else
	304	mem_auto_no++;
	305	}
	306
	307	PRINT_INFO(" number of devices (partitions): %d \n", xpram_devs);
	308	for (i = 0; i < xpram_devs; i++) {
	309	if (xpram_sizes[i])
	310	PRINT_INFO(" size of partition %d: %u kB\n",
	311	i, xpram_sizes[i]);
	312	else
	313	PRINT_INFO(" size of partition %d to be set "
	314	"automatically\n",i);
	315	}
	316	PRINT_DEBUG(" memory needed (for sized partitions): %lu kB\n",
	317	mem_needed);
	318	PRINT_DEBUG(" partitions to be sized automatically: %d\n",
	319	mem_auto_no);
	320
	321	if (mem_needed > pages * 4) {
	322	PRINT_ERR("Not enough expanded memory available\n");
	323	return -EINVAL;
	324	}
	325
	326	/*
	327	* partitioning:
	328	* xpram_sizes[i] != 0; partition i has size xpram_sizes[i] kB
	329	* else: ; all partitions with zero xpram_sizes[i]
	330	* partition equally the remaining space
	331	*/
	332	if (mem_auto_no) {
	333	mem_auto = ((pages - mem_needed / 4) / mem_auto_no) * 4;
	334	PRINT_INFO(" automatically determined "
	335	"partition size: %lu kB\n", mem_auto);
	336	for (i = 0; i < xpram_devs; i++)
	337	if (xpram_sizes[i] == 0)
	338	xpram_sizes[i] = mem_auto;
	339	}
	340	return 0;
	341	}
	342
	343	static struct request_queue *xpram_queue;
	344
	345	static int __init xpram_setup_blkdev(void)
	346	{
	347	unsigned long offset;
	348	int i, rc = -ENOMEM;
	349
	350	for (i = 0; i < xpram_devs; i++) {
	351	struct gendisk *disk = alloc_disk(1);
	352	if (!disk)
	353	goto out;
	354	xpram_disks[i] = disk;
	355	}
	356
	357	/*
	358	* Register xpram major.
	359	*/
	360	rc = register_blkdev(XPRAM_MAJOR, XPRAM_NAME);
	361	if (rc < 0)
	362	goto out;
	363
1da177e4 LT	364	/*
	365	* Assign the other needed values: make request function, sizes and
	366	* hardsect size. All the minor devices feature the same value.
	367	*/
	368	xpram_queue = blk_alloc_queue(GFP_KERNEL);
	369	if (!xpram_queue) {
	370	rc = -ENOMEM;
	371	goto out_unreg;
	372	}
	373	blk_queue_make_request(xpram_queue, xpram_make_request);
	374	blk_queue_hardsect_size(xpram_queue, 4096);
	375
	376	/*
	377	* Setup device structures.
	378	*/
	379	offset = 0;
	380	for (i = 0; i < xpram_devs; i++) {
	381	struct gendisk *disk = xpram_disks[i];
	382
	383	xpram_devices[i].size = xpram_sizes[i] / 4;
	384	xpram_devices[i].offset = offset;
	385	offset += xpram_devices[i].size;
	386	disk->major = XPRAM_MAJOR;
	387	disk->first_minor = i;
	388	disk->fops = &xpram_devops;
	389	disk->private_data = &xpram_devices[i];
	390	disk->queue = xpram_queue;
	391	sprintf(disk->disk_name, "slram%d", i);
1da177e4 LT	392	set_capacity(disk, xpram_sizes[i] << 1);
	393	add_disk(disk);
	394	}
	395
	396	return 0;
	397	out_unreg:
1da177e4 LT	398	unregister_blkdev(XPRAM_MAJOR, XPRAM_NAME);
	399	out:
	400	while (i--)
	401	put_disk(xpram_disks[i]);
	402	return rc;
	403	}
	404
	405	/*
	406	* Finally, the init/exit functions.
	407	*/
	408	static void __exit xpram_exit(void)
	409	{
	410	int i;
	411	for (i = 0; i < xpram_devs; i++) {
	412	del_gendisk(xpram_disks[i]);
	413	put_disk(xpram_disks[i]);
	414	}
	415	unregister_blkdev(XPRAM_MAJOR, XPRAM_NAME);
1da177e4	416	blk_cleanup_queue(xpram_queue);
1da177e4 LT	417	}
	418
	419	static int __init xpram_init(void)
	420	{
	421	int rc;
	422
	423	/* Find out size of expanded memory. */
	424	if (xpram_present() != 0) {
	425	PRINT_WARN("No expanded memory available\n");
	426	return -ENODEV;
	427	}
e620c494	428	xpram_pages = xpram_highest_page_index() + 1;
1da177e4 LT	429	PRINT_INFO(" %u pages expanded memory found (%lu KB).\n",
	430	xpram_pages, (unsigned long) xpram_pages*4);
	431	rc = xpram_setup_sizes(xpram_pages);
	432	if (rc)
	433	return rc;
37ab46a3	434	return xpram_setup_blkdev();
1da177e4 LT	435	}
	436
	437	module_init(xpram_init);
	438	module_exit(xpram_exit);