[mirror_ubuntu-kernels.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)


static struct sysdev_class xpram_sysclass = {
	set_kset_name("xpram"),
};

static struct sys_device xpram_sys_device = {
	.id	= 0,
	.cls	= &xpram_sysclass,
}; 

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;

	__asm__ __volatile__ (
		"   lhi   %0,2\n"  /* return unused cc 2 if pgin traps */
		"   .insn rre,0xb22e0000,%1,%2\n"  /* pgin %1,%2 */
                "0: ipm   %0\n"
		"   srl   %0,28\n"
		"1:\n"
#ifndef CONFIG_64BIT
		".section __ex_table,\"a\"\n"
		"   .align 4\n"
		"   .long  0b,1b\n"
		".previous"
#else
                ".section __ex_table,\"a\"\n"
                "   .align 8\n"
                "   .quad 0b,1b\n"
                ".previous"
#endif
		: "=&d" (cc) 
		: "a" (__pa(page_addr)), "a" (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;

	__asm__ __volatile__ (
		"   lhi   %0,2\n"  /* return unused cc 2 if pgout traps */
		"   .insn rre,0xb22f0000,%1,%2\n"  /* pgout %1,%2 */
                "0: ipm   %0\n"
		"   srl   %0,28\n"
		"1:\n"
#ifndef CONFIG_64BIT
		".section __ex_table,\"a\"\n"
		"   .align 4\n"
		"   .long  0b,1b\n"
		".previous"
#else
                ".section __ex_table,\"a\"\n"
                "   .align 8\n"
                "   .quad 0b,1b\n"
                ".previous"
#endif
		: "=&d" (cc) 
		: "a" (__pa(page_addr)), "a" (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(request_queue_t *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);
	bytes = bio->bi_size;
	bio->bi_size = 0;
	bio->bi_end_io(bio, bytes, 0);
	return 0;
fail:
	bio_io_error(bio, bio->bi_size);
	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;
	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])
			xpram_sizes[i] =
				(memparse(sizes[i], &sizes[i]) + 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);
	sysdev_unregister(&xpram_sys_device);
	sysdev_class_unregister(&xpram_sysclass);
}

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();
	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;
	rc = sysdev_class_register(&xpram_sysclass);
	if (rc)
		return rc;

	rc = sysdev_register(&xpram_sys_device);
	if (rc) {
		sysdev_class_unregister(&xpram_sysclass);
		return rc;
	}
	rc = xpram_setup_blkdev();
	if (rc)
		sysdev_unregister(&xpram_sys_device);
	return rc;
}

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
	51	static struct sysdev_class xpram_sysclass = {
	52	set_kset_name("xpram"),
	53	};
	54
	55	static struct sys_device xpram_sys_device = {
	56	.id = 0,
	57	.cls = &xpram_sysclass,
	58	};
	59
	60	typedef struct {
	61	unsigned int size; /* size of xpram segment in pages */
	62	unsigned int offset; /* start page of xpram segment */
	63	} xpram_device_t;
	64
	65	static xpram_device_t xpram_devices[XPRAM_MAX_DEVS];
	66	static unsigned int xpram_sizes[XPRAM_MAX_DEVS];
	67	static struct gendisk *xpram_disks[XPRAM_MAX_DEVS];
	68	static unsigned int xpram_pages;
	69	static int xpram_devs;
	70
	71	/*
	72	* Parameter parsing functions.
	73	*/
5c898ba9 HC	74	static int __initdata devs = XPRAM_DEVS;
5c898ba9 HC	75	static char __initdata *sizes[XPRAM_MAX_DEVS];
1da177e4 LT	76
1da177e4 LT	77	module_param(devs, int, 0);
5c898ba9	78	module_param_array(sizes, charp, NULL, 0);
1da177e4 LT	79
	80	MODULE_PARM_DESC(devs, "number of devices (\"partitions\"), " \
	81	"the default is " __MODULE_STRING(XPRAM_DEVS) "\n");
	82	MODULE_PARM_DESC(sizes, "list of device (partition) sizes " \
	83	"the defaults are 0s \n" \
	84	"All devices with size 0 equally partition the "
	85	"remaining space on the expanded strorage not "
	86	"claimed by explicit sizes\n");
	87	MODULE_LICENSE("GPL");
	88
1da177e4 LT	89	/*
	90	* Copy expanded memory page (4kB) into main memory
	91	* Arguments
	92	* page_addr: address of target page
	93	* xpage_index: index of expandeded memory page
	94	* Return value
	95	* 0: if operation succeeds
	96	* -EIO: if pgin failed
	97	* -ENXIO: if xpram has vanished
	98	*/
	99	static int xpram_page_in (unsigned long page_addr, unsigned int xpage_index)
	100	{
	101	int cc;
	102
	103	__asm__ __volatile__ (
	104	" lhi %0,2\n" /* return unused cc 2 if pgin traps */
	105	" .insn rre,0xb22e0000,%1,%2\n" /* pgin %1,%2 */
	106	"0: ipm %0\n"
	107	" srl %0,28\n"
	108	"1:\n"
347a8dc3	109	#ifndef CONFIG_64BIT
1da177e4 LT	110	".section __ex_table,\"a\"\n"
	111	" .align 4\n"
	112	" .long 0b,1b\n"
	113	".previous"
	114	#else
	115	".section __ex_table,\"a\"\n"
	116	" .align 8\n"
	117	" .quad 0b,1b\n"
	118	".previous"
	119	#endif
	120	: "=&d" (cc)
	121	: "a" (__pa(page_addr)), "a" (xpage_index)
	122	: "cc" );
	123	if (cc == 3)
	124	return -ENXIO;
	125	if (cc == 2) {
	126	PRINT_ERR("expanded storage lost!\n");
	127	return -ENXIO;
	128	}
	129	if (cc == 1) {
	130	PRINT_ERR("page in failed for page index %u.\n",
	131	xpage_index);
	132	return -EIO;
	133	}
	134	return 0;
	135	}
	136
	137	/*
	138	* Copy a 4kB page of main memory to an expanded memory page
	139	* Arguments
	140	* page_addr: address of source page
	141	* xpage_index: index of expandeded memory page
	142	* Return value
	143	* 0: if operation succeeds
	144	* -EIO: if pgout failed
	145	* -ENXIO: if xpram has vanished
	146	*/
	147	static long xpram_page_out (unsigned long page_addr, unsigned int xpage_index)
	148	{
	149	int cc;
	150
	151	__asm__ __volatile__ (
	152	" lhi %0,2\n" /* return unused cc 2 if pgout traps */
	153	" .insn rre,0xb22f0000,%1,%2\n" /* pgout %1,%2 */
	154	"0: ipm %0\n"
	155	" srl %0,28\n"
	156	"1:\n"
347a8dc3	157	#ifndef CONFIG_64BIT
1da177e4 LT	158	".section __ex_table,\"a\"\n"
	159	" .align 4\n"
	160	" .long 0b,1b\n"
	161	".previous"
	162	#else
	163	".section __ex_table,\"a\"\n"
	164	" .align 8\n"
	165	" .quad 0b,1b\n"
	166	".previous"
	167	#endif
	168	: "=&d" (cc)
	169	: "a" (__pa(page_addr)), "a" (xpage_index)
	170	: "cc" );
	171	if (cc == 3)
	172	return -ENXIO;
	173	if (cc == 2) {
	174	PRINT_ERR("expanded storage lost!\n");
	175	return -ENXIO;
	176	}
	177	if (cc == 1) {
	178	PRINT_ERR("page out failed for page index %u.\n",
	179	xpage_index);
	180	return -EIO;
	181	}
	182	return 0;
	183	}
	184
	185	/*
	186	* Check if xpram is available.
	187	*/
	188	static int __init xpram_present(void)
	189	{
	190	unsigned long mem_page;
	191	int rc;
	192
	193	mem_page = (unsigned long) __get_free_page(GFP_KERNEL);
	194	if (!mem_page)
	195	return -ENOMEM;
	196	rc = xpram_page_in(mem_page, 0);
	197	free_page(mem_page);
	198	return rc ? -ENXIO : 0;
	199	}
	200
	201	/*
	202	* Return index of the last available xpram page.
	203	*/
	204	static unsigned long __init xpram_highest_page_index(void)
	205	{
	206	unsigned int page_index, add_bit;
	207	unsigned long mem_page;
	208
	209	mem_page = (unsigned long) __get_free_page(GFP_KERNEL);
	210	if (!mem_page)
	211	return 0;
	212
	213	page_index = 0;
	214	add_bit = 1ULL << (sizeof(unsigned int)*8 - 1);
	215	while (add_bit > 0) {
	216	if (xpram_page_in(mem_page, page_index \| add_bit) == 0)
	217	page_index \|= add_bit;
	218	add_bit >>= 1;
	219	}
	220
	221	free_page (mem_page);
222
223	return page_index;
224	}
225
226	/*
227	* Block device make request function.
228	*/
229	static int xpram_make_request(request_queue_t q, struct bio bio)
230	{
231	xpram_device_t *xdev = bio->bi_bdev->bd_disk->private_data;
232	struct bio_vec *bvec;
233	unsigned int index;
234	unsigned long page_addr;
235	unsigned long bytes;
236	int i;
237
238	if ((bio->bi_sector & 7) != 0 \|\| (bio->bi_size & 4095) != 0)
239	/* Request is not page-aligned. */
240	goto fail;
241	if ((bio->bi_size >> 12) > xdev->size)
242	/* Request size is no page-aligned. */
243	goto fail;
244	if ((bio->bi_sector >> 3) > 0xffffffffU - xdev->offset)
245	goto fail;
246	index = (bio->bi_sector >> 3) + xdev->offset;
247	bio_for_each_segment(bvec, bio, i) {
248	page_addr = (unsigned long)
249	kmap(bvec->bv_page) + bvec->bv_offset;
250	bytes = bvec->bv_len;
251	if ((page_addr & 4095) != 0 \|\| (bytes & 4095) != 0)
252	/* More paranoia. */
253	goto fail;
254	while (bytes > 0) {
255	if (bio_data_dir(bio) == READ) {
256	if (xpram_page_in(page_addr, index) != 0)
257	goto fail;
258	} else {
259	if (xpram_page_out(page_addr, index) != 0)
260	goto fail;
261	}
262	page_addr += 4096;
263	bytes -= 4096;
264	index++;
265	}
266	}
267	set_bit(BIO_UPTODATE, &bio->bi_flags);
268	bytes = bio->bi_size;
269	bio->bi_size = 0;
270	bio->bi_end_io(bio, bytes, 0);
271	return 0;
272	fail:
273	bio_io_error(bio, bio->bi_size);
274	return 0;
275	}
276
a885c8c4	277	static int xpram_getgeo(struct block_device bdev, struct hd_geometry geo)
1da177e4	278	{
1da177e4	279	unsigned long size;
a885c8c4	280
1da177e4 LT	281	/*
	282	* get geometry: we have to fake one... trim the size to a
	283	* multiple of 64 (32k): tell we have 16 sectors, 4 heads,
	284	* whatever cylinders. Tell also that data starts at sector. 4.
	285	*/
1da177e4	286	size = (xpram_pages * 8) & ~0x3f;
a885c8c4 CH	287	geo->cylinders = size >> 6;
	288	geo->heads = 4;
	289	geo->sectors = 16;
	290	geo->start = 4;
1da177e4 LT	291	return 0;
	292	}
	293
	294	static struct block_device_operations xpram_devops =
	295	{
	296	.owner = THIS_MODULE,
a885c8c4	297	.getgeo = xpram_getgeo,
1da177e4 LT	298	};
	299
	300	/*
	301	* Setup xpram_sizes array.
	302	*/
	303	static int __init xpram_setup_sizes(unsigned long pages)
	304	{
	305	unsigned long mem_needed;
	306	unsigned long mem_auto;
	307	int mem_auto_no;
	308	int i;
	309
	310	/* Check number of devices. */
	311	if (devs <= 0 \|\| devs > XPRAM_MAX_DEVS) {
	312	PRINT_ERR("invalid number %d of devices\n",devs);
	313	return -EINVAL;
	314	}
	315	xpram_devs = devs;
	316
	317	/*
	318	* Copy sizes array to xpram_sizes and align partition
	319	* sizes to page boundary.
	320	*/
	321	mem_needed = 0;
	322	mem_auto_no = 0;
	323	for (i = 0; i < xpram_devs; i++) {
5c898ba9 HC	324	if (sizes[i])
	325	xpram_sizes[i] =
	326	(memparse(sizes[i], &sizes[i]) + 3) & -4UL;
1da177e4 LT	327	if (xpram_sizes[i])
	328	mem_needed += xpram_sizes[i];
	329	else
	330	mem_auto_no++;
	331	}
	332
	333	PRINT_INFO(" number of devices (partitions): %d \n", xpram_devs);
	334	for (i = 0; i < xpram_devs; i++) {
	335	if (xpram_sizes[i])
	336	PRINT_INFO(" size of partition %d: %u kB\n",
	337	i, xpram_sizes[i]);
	338	else
	339	PRINT_INFO(" size of partition %d to be set "
	340	"automatically\n",i);
	341	}
	342	PRINT_DEBUG(" memory needed (for sized partitions): %lu kB\n",
	343	mem_needed);
	344	PRINT_DEBUG(" partitions to be sized automatically: %d\n",
	345	mem_auto_no);
	346
	347	if (mem_needed > pages * 4) {
	348	PRINT_ERR("Not enough expanded memory available\n");
	349	return -EINVAL;
	350	}
	351
	352	/*
	353	* partitioning:
	354	* xpram_sizes[i] != 0; partition i has size xpram_sizes[i] kB
	355	* else: ; all partitions with zero xpram_sizes[i]
	356	* partition equally the remaining space
	357	*/
	358	if (mem_auto_no) {
	359	mem_auto = ((pages - mem_needed / 4) / mem_auto_no) * 4;
	360	PRINT_INFO(" automatically determined "
	361	"partition size: %lu kB\n", mem_auto);
	362	for (i = 0; i < xpram_devs; i++)
	363	if (xpram_sizes[i] == 0)
	364	xpram_sizes[i] = mem_auto;
	365	}
	366	return 0;
	367	}
	368
	369	static struct request_queue *xpram_queue;
	370
	371	static int __init xpram_setup_blkdev(void)
	372	{
	373	unsigned long offset;
	374	int i, rc = -ENOMEM;
	375
	376	for (i = 0; i < xpram_devs; i++) {
	377	struct gendisk *disk = alloc_disk(1);
	378	if (!disk)
	379	goto out;
	380	xpram_disks[i] = disk;
	381	}
	382
	383	/*
	384	* Register xpram major.
	385	*/
	386	rc = register_blkdev(XPRAM_MAJOR, XPRAM_NAME);
	387	if (rc < 0)
	388	goto out;
	389
1da177e4 LT	390	/*
	391	* Assign the other needed values: make request function, sizes and
	392	* hardsect size. All the minor devices feature the same value.
	393	*/
	394	xpram_queue = blk_alloc_queue(GFP_KERNEL);
	395	if (!xpram_queue) {
	396	rc = -ENOMEM;
	397	goto out_unreg;
	398	}
	399	blk_queue_make_request(xpram_queue, xpram_make_request);
	400	blk_queue_hardsect_size(xpram_queue, 4096);
	401
	402	/*
	403	* Setup device structures.
	404	*/
	405	offset = 0;
	406	for (i = 0; i < xpram_devs; i++) {
	407	struct gendisk *disk = xpram_disks[i];
	408
	409	xpram_devices[i].size = xpram_sizes[i] / 4;
	410	xpram_devices[i].offset = offset;
	411	offset += xpram_devices[i].size;
	412	disk->major = XPRAM_MAJOR;
	413	disk->first_minor = i;
	414	disk->fops = &xpram_devops;
	415	disk->private_data = &xpram_devices[i];
	416	disk->queue = xpram_queue;
	417	sprintf(disk->disk_name, "slram%d", i);
1da177e4 LT	418	set_capacity(disk, xpram_sizes[i] << 1);
	419	add_disk(disk);
	420	}
	421
	422	return 0;
	423	out_unreg:
1da177e4 LT	424	unregister_blkdev(XPRAM_MAJOR, XPRAM_NAME);
	425	out:
	426	while (i--)
	427	put_disk(xpram_disks[i]);
	428	return rc;
	429	}
	430
	431	/*
	432	* Finally, the init/exit functions.
	433	*/
	434	static void __exit xpram_exit(void)
	435	{
	436	int i;
	437	for (i = 0; i < xpram_devs; i++) {
	438	del_gendisk(xpram_disks[i]);
	439	put_disk(xpram_disks[i]);
	440	}
	441	unregister_blkdev(XPRAM_MAJOR, XPRAM_NAME);
1da177e4 LT	442	blk_cleanup_queue(xpram_queue);
	443	sysdev_unregister(&xpram_sys_device);
	444	sysdev_class_unregister(&xpram_sysclass);
	445	}
	446
	447	static int __init xpram_init(void)
	448	{
	449	int rc;
	450
	451	/* Find out size of expanded memory. */
	452	if (xpram_present() != 0) {
	453	PRINT_WARN("No expanded memory available\n");
	454	return -ENODEV;
	455	}
	456	xpram_pages = xpram_highest_page_index();
	457	PRINT_INFO(" %u pages expanded memory found (%lu KB).\n",
	458	xpram_pages, (unsigned long) xpram_pages*4);
	459	rc = xpram_setup_sizes(xpram_pages);
	460	if (rc)
	461	return rc;
	462	rc = sysdev_class_register(&xpram_sysclass);
	463	if (rc)
	464	return rc;
	465
	466	rc = sysdev_register(&xpram_sys_device);
	467	if (rc) {
	468	sysdev_class_unregister(&xpram_sysclass);
	469	return rc;
	470	}
	471	rc = xpram_setup_blkdev();
	472	if (rc)
	473	sysdev_unregister(&xpram_sys_device);
	474	return rc;
	475	}
	476
	477	module_init(xpram_init);
	478	module_exit(xpram_exit);