[deliverable/linux.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
 */

#define KMSG_COMPONENT "xpram"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/ctype.h>  /* isdigit, isxdigit */
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/blkdev.h>
#include <linux/blkpg.h>
#include <linux/hdreg.h>  /* HDIO_GETGEO */
#include <linux/device.h>
#include <linux/bio.h>
#include <linux/suspend.h>
#include <linux/platform_device.h>
#include <linux/gfp.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) */

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 struct request_queue *xpram_queues[XPRAM_MAX_DEVS];
static unsigned int xpram_pages;
static int xpram_devs;

/*
 * Parameter parsing functions.
 */
static int devs = XPRAM_DEVS;
static char *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)
		return -ENXIO;
	if (cc == 1)
		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)
		return -ENXIO;
	if (cc == 1)
		return -EIO;
	return 0;
}

/*
 * Check if xpram is available.
 */
static int 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 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 void 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;
	struct bvec_iter iter;
	unsigned int index;
	unsigned long page_addr;
	unsigned long bytes;

	blk_queue_split(q, &bio, q->bio_split);

	if ((bio->bi_iter.bi_sector & 7) != 0 ||
	    (bio->bi_iter.bi_size & 4095) != 0)
		/* Request is not page-aligned. */
		goto fail;
	if ((bio->bi_iter.bi_size >> 12) > xdev->size)
		/* Request size is no page-aligned. */
		goto fail;
	if ((bio->bi_iter.bi_sector >> 3) > 0xffffffffU - xdev->offset)
		goto fail;
	index = (bio->bi_iter.bi_sector >> 3) + xdev->offset;
	bio_for_each_segment(bvec, bio, iter) {
		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++;
		}
	}
	bio_endio(bio);
	return;
fail:
	bio_io_error(bio);
}

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 const 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;
	char *sizes_end;
	int mem_auto_no;
	int i;

	/* Check number of devices. */
	if (devs <= 0 || devs > XPRAM_MAX_DEVS) {
		pr_err("%d is not a valid number of XPRAM 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_end, 0);
			switch (*sizes_end) {
			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++;
	}
	
	pr_info("  number of devices (partitions): %d \n", xpram_devs);
	for (i = 0; i < xpram_devs; i++) {
		if (xpram_sizes[i])
			pr_info("  size of partition %d: %u kB\n",
				i, xpram_sizes[i]);
		else
			pr_info("  size of partition %d to be set "
				"automatically\n",i);
	}
	pr_info("  memory needed (for sized partitions): %lu kB\n",
		mem_needed);
	pr_info("  partitions to be sized automatically: %d\n",
		mem_auto_no);

	if (mem_needed > pages * 4) {
		pr_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;
		pr_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 int __init xpram_setup_blkdev(void)
{
	unsigned long offset;
	int i, rc = -ENOMEM;

	for (i = 0; i < xpram_devs; i++) {
		xpram_disks[i] = alloc_disk(1);
		if (!xpram_disks[i])
			goto out;
		xpram_queues[i] = blk_alloc_queue(GFP_KERNEL);
		if (!xpram_queues[i]) {
			put_disk(xpram_disks[i]);
			goto out;
		}
		queue_flag_set_unlocked(QUEUE_FLAG_NONROT, xpram_queues[i]);
		queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, xpram_queues[i]);
		blk_queue_make_request(xpram_queues[i], xpram_make_request);
		blk_queue_logical_block_size(xpram_queues[i], 4096);
	}

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

	/*
	 * 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_queues[i];
		sprintf(disk->disk_name, "slram%d", i);
		set_capacity(disk, xpram_sizes[i] << 1);
		add_disk(disk);
	}

	return 0;
out:
	while (i--) {
		blk_cleanup_queue(xpram_queues[i]);
		put_disk(xpram_disks[i]);
	}
	return rc;
}

/*
 * Resume failed: Print error message and call panic.
 */
static void xpram_resume_error(const char *message)
{
	pr_err("Resuming the system failed: %s\n", message);
	panic("xpram resume error\n");
}

/*
 * Check if xpram setup changed between suspend and resume.
 */
static int xpram_restore(struct device *dev)
{
	if (!xpram_pages)
		return 0;
	if (xpram_present() != 0)
		xpram_resume_error("xpram disappeared");
	if (xpram_pages != xpram_highest_page_index() + 1)
		xpram_resume_error("Size of xpram changed");
	return 0;
}

static const struct dev_pm_ops xpram_pm_ops = {
	.restore	= xpram_restore,
};

static struct platform_driver xpram_pdrv = {
	.driver = {
		.name	= XPRAM_NAME,
		.pm	= &xpram_pm_ops,
	},
};

static struct platform_device *xpram_pdev;

/*
 * 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]);
		blk_cleanup_queue(xpram_queues[i]);
		put_disk(xpram_disks[i]);
	}
	unregister_blkdev(XPRAM_MAJOR, XPRAM_NAME);
	platform_device_unregister(xpram_pdev);
	platform_driver_unregister(&xpram_pdrv);
}

static int __init xpram_init(void)
{
	int rc;

	/* Find out size of expanded memory. */
	if (xpram_present() != 0) {
		pr_err("No expanded memory available\n");
		return -ENODEV;
	}
	xpram_pages = xpram_highest_page_index() + 1;
	pr_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 = platform_driver_register(&xpram_pdrv);
	if (rc)
		return rc;
	xpram_pdev = platform_device_register_simple(XPRAM_NAME, -1, NULL, 0);
	if (IS_ERR(xpram_pdev)) {
		rc = PTR_ERR(xpram_pdev);
		goto fail_platform_driver_unregister;
	}
	rc = xpram_setup_blkdev();
	if (rc)
		goto fail_platform_device_unregister;
	return 0;

fail_platform_device_unregister:
	platform_device_unregister(xpram_pdev);
fail_platform_driver_unregister:
	platform_driver_unregister(&xpram_pdrv);
	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
d1c2f892 MS	28	#define KMSG_COMPONENT "xpram"
	29	#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
	30
1da177e4 LT	31	#include <linux/module.h>
	32	#include <linux/moduleparam.h>
	33	#include <linux/ctype.h> /* isdigit, isxdigit */
	34	#include <linux/errno.h>
	35	#include <linux/init.h>
1da177e4 LT	36	#include <linux/blkdev.h>
	37	#include <linux/blkpg.h>
	38	#include <linux/hdreg.h> /* HDIO_GETGEO */
edbaa603	39	#include <linux/device.h>
1da177e4	40	#include <linux/bio.h>
14532095 MH	41	#include <linux/suspend.h>
14532095 MH	42	#include <linux/platform_device.h>
5a0e3ad6	43	#include <linux/gfp.h>
1da177e4 LT	44	#include <asm/uaccess.h>
	45
	46	#define XPRAM_NAME "xpram"
	47	#define XPRAM_DEVS 1 /* one partition */
	48	#define XPRAM_MAX_DEVS 32 /* maximal number of devices (partitions) */
	49
1da177e4 LT	50	typedef struct {
	51	unsigned int size; /* size of xpram segment in pages */
	52	unsigned int offset; /* start page of xpram segment */
	53	} xpram_device_t;
	54
	55	static xpram_device_t xpram_devices[XPRAM_MAX_DEVS];
	56	static unsigned int xpram_sizes[XPRAM_MAX_DEVS];
	57	static struct gendisk *xpram_disks[XPRAM_MAX_DEVS];
3ce66093	58	static struct request_queue *xpram_queues[XPRAM_MAX_DEVS];
1da177e4 LT	59	static unsigned int xpram_pages;
	60	static int xpram_devs;
	61
	62	/*
	63	* Parameter parsing functions.
	64	*/
0c0db035 MS	65	static int devs = XPRAM_DEVS;
0c0db035 MS	66	static char *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)
1da177e4 LT	102	return -ENXIO;
8df22b4b	103	if (cc == 2)
1da177e4	104	return -ENXIO;
8df22b4b	105	if (cc == 1)
1da177e4	106	return -EIO;
1da177e4 LT	107	return 0;
	108	}
	109
	110	/*
	111	* Copy a 4kB page of main memory to an expanded memory page
	112	* Arguments
	113	* page_addr: address of source page
	114	* xpage_index: index of expandeded memory page
	115	* Return value
	116	* 0: if operation succeeds
	117	* -EIO: if pgout failed
	118	* -ENXIO: if xpram has vanished
	119	*/
	120	static long xpram_page_out (unsigned long page_addr, unsigned int xpage_index)
	121	{
94c12cc7	122	int cc = 2; /* return unused cc 2 if pgin traps */
1da177e4	123
94c12cc7 MS	124	asm volatile(
	125	" .insn rre,0xb22f0000,%1,%2\n" /* pgout %1,%2 */
	126	"0: ipm %0\n"
	127	" srl %0,28\n"
1da177e4	128	"1:\n"
94c12cc7 MS	129	EX_TABLE(0b,1b)
94c12cc7 MS	130	: "+d" (cc) : "a" (__pa(page_addr)), "d" (xpage_index) : "cc");
1da177e4 LT	131	if (cc == 3)
1da177e4 LT	132	return -ENXIO;
8df22b4b	133	if (cc == 2)
1da177e4	134	return -ENXIO;
8df22b4b	135	if (cc == 1)
1da177e4	136	return -EIO;
1da177e4 LT	137	return 0;
	138	}
	139
	140	/*
	141	* Check if xpram is available.
	142	*/
14532095	143	static int xpram_present(void)
1da177e4 LT	144	{
	145	unsigned long mem_page;
	146	int rc;
	147
	148	mem_page = (unsigned long) __get_free_page(GFP_KERNEL);
	149	if (!mem_page)
	150	return -ENOMEM;
	151	rc = xpram_page_in(mem_page, 0);
	152	free_page(mem_page);
	153	return rc ? -ENXIO : 0;
	154	}
	155
	156	/*
	157	* Return index of the last available xpram page.
	158	*/
14532095	159	static unsigned long xpram_highest_page_index(void)
1da177e4 LT	160	{
	161	unsigned int page_index, add_bit;
	162	unsigned long mem_page;
	163
	164	mem_page = (unsigned long) __get_free_page(GFP_KERNEL);
	165	if (!mem_page)
	166	return 0;
	167
	168	page_index = 0;
	169	add_bit = 1ULL << (sizeof(unsigned int)*8 - 1);
	170	while (add_bit > 0) {
	171	if (xpram_page_in(mem_page, page_index \| add_bit) == 0)
	172	page_index \|= add_bit;
	173	add_bit >>= 1;
	174	}
	175
	176	free_page (mem_page);
	177
	178	return page_index;
	179	}
	180
	181	/*
	182	* Block device make request function.
	183	*/
5a7bbad2	184	static void xpram_make_request(struct request_queue q, struct bio bio)
1da177e4 LT	185	{
1da177e4 LT	186	xpram_device_t *xdev = bio->bi_bdev->bd_disk->private_data;
7988613b KO	187	struct bio_vec bvec;
7988613b KO	188	struct bvec_iter iter;
1da177e4 LT	189	unsigned int index;
	190	unsigned long page_addr;
	191	unsigned long bytes;
1da177e4	192
54efd50b KO	193	blk_queue_split(q, &bio, q->bio_split);
54efd50b KO	194
4f024f37 KO	195	if ((bio->bi_iter.bi_sector & 7) != 0 \|\|
4f024f37 KO	196	(bio->bi_iter.bi_size & 4095) != 0)
1da177e4 LT	197	/* Request is not page-aligned. */
1da177e4 LT	198	goto fail;
4f024f37	199	if ((bio->bi_iter.bi_size >> 12) > xdev->size)
1da177e4 LT	200	/* Request size is no page-aligned. */
1da177e4 LT	201	goto fail;
4f024f37	202	if ((bio->bi_iter.bi_sector >> 3) > 0xffffffffU - xdev->offset)
1da177e4	203	goto fail;
4f024f37	204	index = (bio->bi_iter.bi_sector >> 3) + xdev->offset;
7988613b	205	bio_for_each_segment(bvec, bio, iter) {
1da177e4	206	page_addr = (unsigned long)
7988613b KO	207	kmap(bvec.bv_page) + bvec.bv_offset;
7988613b KO	208	bytes = bvec.bv_len;
1da177e4 LT	209	if ((page_addr & 4095) != 0 \|\| (bytes & 4095) != 0)
	210	/* More paranoia. */
	211	goto fail;
	212	while (bytes > 0) {
	213	if (bio_data_dir(bio) == READ) {
	214	if (xpram_page_in(page_addr, index) != 0)
	215	goto fail;
	216	} else {
	217	if (xpram_page_out(page_addr, index) != 0)
	218	goto fail;
	219	}
	220	page_addr += 4096;
	221	bytes -= 4096;
	222	index++;
	223	}
	224	}
4246a0b6	225	bio_endio(bio);
5a7bbad2	226	return;
1da177e4	227	fail:
6712ecf8	228	bio_io_error(bio);
1da177e4 LT	229	}
1da177e4 LT	230
a885c8c4	231	static int xpram_getgeo(struct block_device bdev, struct hd_geometry geo)
1da177e4	232	{
1da177e4	233	unsigned long size;
a885c8c4	234
1da177e4 LT	235	/*
	236	* get geometry: we have to fake one... trim the size to a
	237	* multiple of 64 (32k): tell we have 16 sectors, 4 heads,
	238	* whatever cylinders. Tell also that data starts at sector. 4.
	239	*/
1da177e4	240	size = (xpram_pages * 8) & ~0x3f;
a885c8c4 CH	241	geo->cylinders = size >> 6;
	242	geo->heads = 4;
	243	geo->sectors = 16;
	244	geo->start = 4;
1da177e4 LT	245	return 0;
	246	}
	247
83d5cde4	248	static const struct block_device_operations xpram_devops =
1da177e4 LT	249	{
1da177e4 LT	250	.owner = THIS_MODULE,
a885c8c4	251	.getgeo = xpram_getgeo,
1da177e4 LT	252	};
	253
	254	/*
	255	* Setup xpram_sizes array.
	256	*/
	257	static int __init xpram_setup_sizes(unsigned long pages)
	258	{
	259	unsigned long mem_needed;
	260	unsigned long mem_auto;
f257b063	261	unsigned long long size;
7e2e2b96	262	char *sizes_end;
1da177e4 LT	263	int mem_auto_no;
	264	int i;
	265
	266	/* Check number of devices. */
	267	if (devs <= 0 \|\| devs > XPRAM_MAX_DEVS) {
d1c2f892	268	pr_err("%d is not a valid number of XPRAM devices\n",devs);
1da177e4 LT	269	return -EINVAL;
	270	}
	271	xpram_devs = devs;
	272
	273	/*
	274	* Copy sizes array to xpram_sizes and align partition
	275	* sizes to page boundary.
	276	*/
	277	mem_needed = 0;
	278	mem_auto_no = 0;
	279	for (i = 0; i < xpram_devs; i++) {
f257b063	280	if (sizes[i]) {
7e2e2b96 SO	281	size = simple_strtoull(sizes[i], &sizes_end, 0);
7e2e2b96 SO	282	switch (*sizes_end) {
f257b063 HC	283	case 'g':
	284	case 'G':
	285	size <<= 20;
	286	break;
	287	case 'm':
	288	case 'M':
	289	size <<= 10;
	290	}
	291	xpram_sizes[i] = (size + 3) & -4UL;
	292	}
1da177e4 LT	293	if (xpram_sizes[i])
	294	mem_needed += xpram_sizes[i];
	295	else
	296	mem_auto_no++;
	297	}
	298
d1c2f892	299	pr_info(" number of devices (partitions): %d \n", xpram_devs);
1da177e4 LT	300	for (i = 0; i < xpram_devs; i++) {
1da177e4 LT	301	if (xpram_sizes[i])
d1c2f892 MS	302	pr_info(" size of partition %d: %u kB\n",
d1c2f892 MS	303	i, xpram_sizes[i]);
1da177e4	304	else
d1c2f892 MS	305	pr_info(" size of partition %d to be set "
d1c2f892 MS	306	"automatically\n",i);
1da177e4	307	}
d1c2f892 MS	308	pr_info(" memory needed (for sized partitions): %lu kB\n",
	309	mem_needed);
	310	pr_info(" partitions to be sized automatically: %d\n",
	311	mem_auto_no);
1da177e4 LT	312
1da177e4 LT	313	if (mem_needed > pages * 4) {
d1c2f892	314	pr_err("Not enough expanded memory available\n");
1da177e4 LT	315	return -EINVAL;
	316	}
	317
	318	/*
	319	* partitioning:
	320	* xpram_sizes[i] != 0; partition i has size xpram_sizes[i] kB
	321	* else: ; all partitions with zero xpram_sizes[i]
	322	* partition equally the remaining space
	323	*/
	324	if (mem_auto_no) {
	325	mem_auto = ((pages - mem_needed / 4) / mem_auto_no) * 4;
d1c2f892 MS	326	pr_info(" automatically determined "
d1c2f892 MS	327	"partition size: %lu kB\n", mem_auto);
1da177e4 LT	328	for (i = 0; i < xpram_devs; i++)
	329	if (xpram_sizes[i] == 0)
	330	xpram_sizes[i] = mem_auto;
	331	}
	332	return 0;
	333	}
	334
1da177e4 LT	335	static int __init xpram_setup_blkdev(void)
	336	{
	337	unsigned long offset;
	338	int i, rc = -ENOMEM;
	339
	340	for (i = 0; i < xpram_devs; i++) {
3ce66093 MS	341	xpram_disks[i] = alloc_disk(1);
	342	if (!xpram_disks[i])
	343	goto out;
	344	xpram_queues[i] = blk_alloc_queue(GFP_KERNEL);
	345	if (!xpram_queues[i]) {
	346	put_disk(xpram_disks[i]);
1da177e4	347	goto out;
3ce66093	348	}
00e5d35c	349	queue_flag_set_unlocked(QUEUE_FLAG_NONROT, xpram_queues[i]);
b277da0a	350	queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, xpram_queues[i]);
3ce66093	351	blk_queue_make_request(xpram_queues[i], xpram_make_request);
e1defc4f	352	blk_queue_logical_block_size(xpram_queues[i], 4096);
1da177e4 LT	353	}
	354
	355	/*
	356	* Register xpram major.
	357	*/
	358	rc = register_blkdev(XPRAM_MAJOR, XPRAM_NAME);
	359	if (rc < 0)
	360	goto out;
	361
1da177e4 LT	362	/*
	363	* Setup device structures.
	364	*/
	365	offset = 0;
	366	for (i = 0; i < xpram_devs; i++) {
	367	struct gendisk *disk = xpram_disks[i];
	368
	369	xpram_devices[i].size = xpram_sizes[i] / 4;
	370	xpram_devices[i].offset = offset;
	371	offset += xpram_devices[i].size;
	372	disk->major = XPRAM_MAJOR;
	373	disk->first_minor = i;
	374	disk->fops = &xpram_devops;
	375	disk->private_data = &xpram_devices[i];
3ce66093	376	disk->queue = xpram_queues[i];
1da177e4	377	sprintf(disk->disk_name, "slram%d", i);
1da177e4 LT	378	set_capacity(disk, xpram_sizes[i] << 1);
	379	add_disk(disk);
	380	}
	381
	382	return 0;
1da177e4	383	out:
3ce66093 MS	384	while (i--) {
3ce66093 MS	385	blk_cleanup_queue(xpram_queues[i]);
1da177e4	386	put_disk(xpram_disks[i]);
3ce66093	387	}
1da177e4 LT	388	return rc;
	389	}
	390
14532095 MH	391	/*
	392	* Resume failed: Print error message and call panic.
	393	*/
	394	static void xpram_resume_error(const char *message)
	395	{
2c48c4d6	396	pr_err("Resuming the system failed: %s\n", message);
14532095 MH	397	panic("xpram resume error\n");
	398	}
	399
	400	/*
	401	* Check if xpram setup changed between suspend and resume.
	402	*/
	403	static int xpram_restore(struct device *dev)
	404	{
	405	if (!xpram_pages)
	406	return 0;
	407	if (xpram_present() != 0)
	408	xpram_resume_error("xpram disappeared");
	409	if (xpram_pages != xpram_highest_page_index() + 1)
	410	xpram_resume_error("Size of xpram changed");
14532095 MH	411	return 0;
	412	}
	413
47145210	414	static const struct dev_pm_ops xpram_pm_ops = {
14532095 MH	415	.restore = xpram_restore,
	416	};
	417
	418	static struct platform_driver xpram_pdrv = {
	419	.driver = {
	420	.name = XPRAM_NAME,
14532095 MH	421	.pm = &xpram_pm_ops,
	422	},
	423	};
	424
	425	static struct platform_device *xpram_pdev;
	426
1da177e4 LT	427	/*
	428	* Finally, the init/exit functions.
	429	*/
	430	static void __exit xpram_exit(void)
	431	{
	432	int i;
	433	for (i = 0; i < xpram_devs; i++) {
	434	del_gendisk(xpram_disks[i]);
3ce66093	435	blk_cleanup_queue(xpram_queues[i]);
1da177e4 LT	436	put_disk(xpram_disks[i]);
	437	}
	438	unregister_blkdev(XPRAM_MAJOR, XPRAM_NAME);
14532095 MH	439	platform_device_unregister(xpram_pdev);
14532095 MH	440	platform_driver_unregister(&xpram_pdrv);
1da177e4 LT	441	}
	442
	443	static int __init xpram_init(void)
	444	{
	445	int rc;
	446
	447	/* Find out size of expanded memory. */
	448	if (xpram_present() != 0) {
d1c2f892	449	pr_err("No expanded memory available\n");
1da177e4 LT	450	return -ENODEV;
1da177e4 LT	451	}
e620c494	452	xpram_pages = xpram_highest_page_index() + 1;
d1c2f892 MS	453	pr_info(" %u pages expanded memory found (%lu KB).\n",
d1c2f892 MS	454	xpram_pages, (unsigned long) xpram_pages*4);
1da177e4 LT	455	rc = xpram_setup_sizes(xpram_pages);
	456	if (rc)
	457	return rc;
14532095 MH	458	rc = platform_driver_register(&xpram_pdrv);
	459	if (rc)
	460	return rc;
	461	xpram_pdev = platform_device_register_simple(XPRAM_NAME, -1, NULL, 0);
	462	if (IS_ERR(xpram_pdev)) {
	463	rc = PTR_ERR(xpram_pdev);
	464	goto fail_platform_driver_unregister;
	465	}
	466	rc = xpram_setup_blkdev();
	467	if (rc)
	468	goto fail_platform_device_unregister;
	469	return 0;
	470
	471	fail_platform_device_unregister:
	472	platform_device_unregister(xpram_pdev);
	473	fail_platform_driver_unregister:
	474	platform_driver_unregister(&xpram_pdrv);
	475	return rc;
1da177e4 LT	476	}
	477
	478	module_init(xpram_init);
	479	module_exit(xpram_exit);