[mirror_ubuntu-bionic-kernel.git] / drivers / s390 / block / xpram.c

// SPDX-License-Identifier: GPL-2.0
/*
 * 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 <linux/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 blk_qc_t xpram_make_request(struct request_queue *q, struct bio *bio)
{
	xpram_device_t *xdev = bio->bi_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);

	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 BLK_QC_T_NONE;
fail:
	bio_io_error(bio);
	return BLK_QC_T_NONE;
}

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
6a55d2cd	1	// SPDX-License-Identifier: GPL-2.0
1da177e4 LT	2	/*
	3	* Xpram.c -- the S/390 expanded memory RAM-disk
	4	*
	5	* significant parts of this code are based on
	6	* the sbull device driver presented in
	7	* A. Rubini: Linux Device Drivers
	8	*
	9	* Author of XPRAM specific coding: Reinhard Buendgen
	10	* buendgen@de.ibm.com
	11	* Rewrite for 2.5: Martin Schwidefsky <schwidefsky@de.ibm.com>
	12	*
	13	* External interfaces:
	14	* Interfaces to linux kernel
	15	* xpram_setup: read kernel parameters
	16	* Device specific file operations
	17	* xpram_iotcl
	18	* xpram_open
	19	*
	20	* "ad-hoc" partitioning:
	21	* the expanded memory can be partitioned among several devices
	22	* (with different minors). The partitioning set up can be
	23	* set by kernel or module parameters (int devs & int sizes[])
	24	*
	25	* Potential future improvements:
	26	* generic hard disk support to replace ad-hoc partitioning
	27	*/
	28
d1c2f892 MS	29	#define KMSG_COMPONENT "xpram"
	30	#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
	31
1da177e4 LT	32	#include <linux/module.h>
	33	#include <linux/moduleparam.h>
	34	#include <linux/ctype.h> /* isdigit, isxdigit */
	35	#include <linux/errno.h>
	36	#include <linux/init.h>
1da177e4 LT	37	#include <linux/blkdev.h>
	38	#include <linux/blkpg.h>
	39	#include <linux/hdreg.h> /* HDIO_GETGEO */
edbaa603	40	#include <linux/device.h>
1da177e4	41	#include <linux/bio.h>
14532095 MH	42	#include <linux/suspend.h>
14532095 MH	43	#include <linux/platform_device.h>
5a0e3ad6	44	#include <linux/gfp.h>
7c0f6ba6	45	#include <linux/uaccess.h>
1da177e4 LT	46
	47	#define XPRAM_NAME "xpram"
	48	#define XPRAM_DEVS 1 /* one partition */
	49	#define XPRAM_MAX_DEVS 32 /* maximal number of devices (partitions) */
	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];
3ce66093	59	static struct request_queue *xpram_queues[XPRAM_MAX_DEVS];
1da177e4 LT	60	static unsigned int xpram_pages;
	61	static int xpram_devs;
	62
	63	/*
	64	* Parameter parsing functions.
	65	*/
0c0db035 MS	66	static int devs = XPRAM_DEVS;
0c0db035 MS	67	static char *sizes[XPRAM_MAX_DEVS];
1da177e4 LT	68
1da177e4 LT	69	module_param(devs, int, 0);
5c898ba9	70	module_param_array(sizes, charp, NULL, 0);
1da177e4 LT	71
	72	MODULE_PARM_DESC(devs, "number of devices (\"partitions\"), " \
	73	"the default is " __MODULE_STRING(XPRAM_DEVS) "\n");
	74	MODULE_PARM_DESC(sizes, "list of device (partition) sizes " \
	75	"the defaults are 0s \n" \
	76	"All devices with size 0 equally partition the "
	77	"remaining space on the expanded strorage not "
	78	"claimed by explicit sizes\n");
	79	MODULE_LICENSE("GPL");
	80
1da177e4 LT	81	/*
	82	* Copy expanded memory page (4kB) into main memory
	83	* Arguments
	84	* page_addr: address of target page
	85	* xpage_index: index of expandeded memory page
	86	* Return value
	87	* 0: if operation succeeds
	88	* -EIO: if pgin failed
	89	* -ENXIO: if xpram has vanished
	90	*/
	91	static int xpram_page_in (unsigned long page_addr, unsigned int xpage_index)
	92	{
94c12cc7	93	int cc = 2; /* return unused cc 2 if pgin traps */
1da177e4	94
94c12cc7 MS	95	asm volatile(
	96	" .insn rre,0xb22e0000,%1,%2\n" /* pgin %1,%2 */
	97	"0: ipm %0\n"
	98	" srl %0,28\n"
1da177e4	99	"1:\n"
94c12cc7 MS	100	EX_TABLE(0b,1b)
94c12cc7 MS	101	: "+d" (cc) : "a" (__pa(page_addr)), "d" (xpage_index) : "cc");
1da177e4 LT	102	if (cc == 3)
1da177e4 LT	103	return -ENXIO;
8df22b4b	104	if (cc == 2)
1da177e4	105	return -ENXIO;
8df22b4b	106	if (cc == 1)
1da177e4	107	return -EIO;
1da177e4 LT	108	return 0;
	109	}
	110
	111	/*
	112	* Copy a 4kB page of main memory to an expanded memory page
	113	* Arguments
	114	* page_addr: address of source page
	115	* xpage_index: index of expandeded memory page
	116	* Return value
	117	* 0: if operation succeeds
	118	* -EIO: if pgout failed
	119	* -ENXIO: if xpram has vanished
	120	*/
	121	static long xpram_page_out (unsigned long page_addr, unsigned int xpage_index)
	122	{
94c12cc7	123	int cc = 2; /* return unused cc 2 if pgin traps */
1da177e4	124
94c12cc7 MS	125	asm volatile(
	126	" .insn rre,0xb22f0000,%1,%2\n" /* pgout %1,%2 */
	127	"0: ipm %0\n"
	128	" srl %0,28\n"
1da177e4	129	"1:\n"
94c12cc7 MS	130	EX_TABLE(0b,1b)
94c12cc7 MS	131	: "+d" (cc) : "a" (__pa(page_addr)), "d" (xpage_index) : "cc");
1da177e4 LT	132	if (cc == 3)
1da177e4 LT	133	return -ENXIO;
8df22b4b	134	if (cc == 2)
1da177e4	135	return -ENXIO;
8df22b4b	136	if (cc == 1)
1da177e4	137	return -EIO;
1da177e4 LT	138	return 0;
	139	}
	140
	141	/*
	142	* Check if xpram is available.
	143	*/
14532095	144	static int xpram_present(void)
1da177e4 LT	145	{
	146	unsigned long mem_page;
	147	int rc;
	148
	149	mem_page = (unsigned long) __get_free_page(GFP_KERNEL);
	150	if (!mem_page)
	151	return -ENOMEM;
	152	rc = xpram_page_in(mem_page, 0);
	153	free_page(mem_page);
	154	return rc ? -ENXIO : 0;
	155	}
	156
	157	/*
	158	* Return index of the last available xpram page.
	159	*/
14532095	160	static unsigned long xpram_highest_page_index(void)
1da177e4 LT	161	{
	162	unsigned int page_index, add_bit;
	163	unsigned long mem_page;
	164
	165	mem_page = (unsigned long) __get_free_page(GFP_KERNEL);
	166	if (!mem_page)
	167	return 0;
	168
	169	page_index = 0;
	170	add_bit = 1ULL << (sizeof(unsigned int)*8 - 1);
	171	while (add_bit > 0) {
	172	if (xpram_page_in(mem_page, page_index \| add_bit) == 0)
	173	page_index \|= add_bit;
	174	add_bit >>= 1;
	175	}
	176
	177	free_page (mem_page);
	178
	179	return page_index;
	180	}
	181
	182	/*
	183	* Block device make request function.
	184	*/
dece1635	185	static blk_qc_t xpram_make_request(struct request_queue q, struct bio bio)
1da177e4	186	{
74d46992	187	xpram_device_t *xdev = bio->bi_disk->private_data;
7988613b KO	188	struct bio_vec bvec;
7988613b KO	189	struct bvec_iter iter;
1da177e4 LT	190	unsigned int index;
	191	unsigned long page_addr;
	192	unsigned long bytes;
1da177e4	193
af67c31f	194	blk_queue_split(q, &bio);
54efd50b	195
4f024f37 KO	196	if ((bio->bi_iter.bi_sector & 7) != 0 \|\|
4f024f37 KO	197	(bio->bi_iter.bi_size & 4095) != 0)
1da177e4 LT	198	/* Request is not page-aligned. */
1da177e4 LT	199	goto fail;
4f024f37	200	if ((bio->bi_iter.bi_size >> 12) > xdev->size)
1da177e4 LT	201	/* Request size is no page-aligned. */
1da177e4 LT	202	goto fail;
4f024f37	203	if ((bio->bi_iter.bi_sector >> 3) > 0xffffffffU - xdev->offset)
1da177e4	204	goto fail;
4f024f37	205	index = (bio->bi_iter.bi_sector >> 3) + xdev->offset;
7988613b	206	bio_for_each_segment(bvec, bio, iter) {
1da177e4	207	page_addr = (unsigned long)
7988613b KO	208	kmap(bvec.bv_page) + bvec.bv_offset;
7988613b KO	209	bytes = bvec.bv_len;
1da177e4 LT	210	if ((page_addr & 4095) != 0 \|\| (bytes & 4095) != 0)
	211	/* More paranoia. */
	212	goto fail;
	213	while (bytes > 0) {
	214	if (bio_data_dir(bio) == READ) {
	215	if (xpram_page_in(page_addr, index) != 0)
	216	goto fail;
	217	} else {
	218	if (xpram_page_out(page_addr, index) != 0)
	219	goto fail;
	220	}
	221	page_addr += 4096;
	222	bytes -= 4096;
	223	index++;
	224	}
	225	}
4246a0b6	226	bio_endio(bio);
dece1635	227	return BLK_QC_T_NONE;
1da177e4	228	fail:
6712ecf8	229	bio_io_error(bio);
dece1635	230	return BLK_QC_T_NONE;
1da177e4 LT	231	}
1da177e4 LT	232
a885c8c4	233	static int xpram_getgeo(struct block_device bdev, struct hd_geometry geo)
1da177e4	234	{
1da177e4	235	unsigned long size;
a885c8c4	236
1da177e4 LT	237	/*
	238	* get geometry: we have to fake one... trim the size to a
	239	* multiple of 64 (32k): tell we have 16 sectors, 4 heads,
	240	* whatever cylinders. Tell also that data starts at sector. 4.
	241	*/
1da177e4	242	size = (xpram_pages * 8) & ~0x3f;
a885c8c4 CH	243	geo->cylinders = size >> 6;
	244	geo->heads = 4;
	245	geo->sectors = 16;
	246	geo->start = 4;
1da177e4 LT	247	return 0;
	248	}
	249
83d5cde4	250	static const struct block_device_operations xpram_devops =
1da177e4 LT	251	{
1da177e4 LT	252	.owner = THIS_MODULE,
a885c8c4	253	.getgeo = xpram_getgeo,
1da177e4 LT	254	};
	255
	256	/*
	257	* Setup xpram_sizes array.
	258	*/
	259	static int __init xpram_setup_sizes(unsigned long pages)
	260	{
	261	unsigned long mem_needed;
	262	unsigned long mem_auto;
f257b063	263	unsigned long long size;
7e2e2b96	264	char *sizes_end;
1da177e4 LT	265	int mem_auto_no;
	266	int i;
	267
	268	/* Check number of devices. */
	269	if (devs <= 0 \|\| devs > XPRAM_MAX_DEVS) {
d1c2f892	270	pr_err("%d is not a valid number of XPRAM devices\n",devs);
1da177e4 LT	271	return -EINVAL;
	272	}
	273	xpram_devs = devs;
	274
	275	/*
	276	* Copy sizes array to xpram_sizes and align partition
	277	* sizes to page boundary.
	278	*/
	279	mem_needed = 0;
	280	mem_auto_no = 0;
	281	for (i = 0; i < xpram_devs; i++) {
f257b063	282	if (sizes[i]) {
7e2e2b96 SO	283	size = simple_strtoull(sizes[i], &sizes_end, 0);
7e2e2b96 SO	284	switch (*sizes_end) {
f257b063 HC	285	case 'g':
	286	case 'G':
	287	size <<= 20;
	288	break;
	289	case 'm':
	290	case 'M':
	291	size <<= 10;
	292	}
	293	xpram_sizes[i] = (size + 3) & -4UL;
	294	}
1da177e4 LT	295	if (xpram_sizes[i])
	296	mem_needed += xpram_sizes[i];
	297	else
	298	mem_auto_no++;
	299	}
	300
d1c2f892	301	pr_info(" number of devices (partitions): %d \n", xpram_devs);
1da177e4 LT	302	for (i = 0; i < xpram_devs; i++) {
1da177e4 LT	303	if (xpram_sizes[i])
d1c2f892 MS	304	pr_info(" size of partition %d: %u kB\n",
d1c2f892 MS	305	i, xpram_sizes[i]);
1da177e4	306	else
d1c2f892 MS	307	pr_info(" size of partition %d to be set "
d1c2f892 MS	308	"automatically\n",i);
1da177e4	309	}
d1c2f892 MS	310	pr_info(" memory needed (for sized partitions): %lu kB\n",
	311	mem_needed);
	312	pr_info(" partitions to be sized automatically: %d\n",
	313	mem_auto_no);
1da177e4 LT	314
1da177e4 LT	315	if (mem_needed > pages * 4) {
d1c2f892	316	pr_err("Not enough expanded memory available\n");
1da177e4 LT	317	return -EINVAL;
	318	}
	319
	320	/*
	321	* partitioning:
	322	* xpram_sizes[i] != 0; partition i has size xpram_sizes[i] kB
	323	* else: ; all partitions with zero xpram_sizes[i]
	324	* partition equally the remaining space
	325	*/
	326	if (mem_auto_no) {
	327	mem_auto = ((pages - mem_needed / 4) / mem_auto_no) * 4;
d1c2f892 MS	328	pr_info(" automatically determined "
d1c2f892 MS	329	"partition size: %lu kB\n", mem_auto);
1da177e4 LT	330	for (i = 0; i < xpram_devs; i++)
	331	if (xpram_sizes[i] == 0)
	332	xpram_sizes[i] = mem_auto;
	333	}
	334	return 0;
	335	}
	336
1da177e4 LT	337	static int __init xpram_setup_blkdev(void)
	338	{
	339	unsigned long offset;
	340	int i, rc = -ENOMEM;
	341
	342	for (i = 0; i < xpram_devs; i++) {
3ce66093 MS	343	xpram_disks[i] = alloc_disk(1);
	344	if (!xpram_disks[i])
	345	goto out;
	346	xpram_queues[i] = blk_alloc_queue(GFP_KERNEL);
	347	if (!xpram_queues[i]) {
	348	put_disk(xpram_disks[i]);
1da177e4	349	goto out;
3ce66093	350	}
00e5d35c	351	queue_flag_set_unlocked(QUEUE_FLAG_NONROT, xpram_queues[i]);
b277da0a	352	queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, xpram_queues[i]);
3ce66093	353	blk_queue_make_request(xpram_queues[i], xpram_make_request);
e1defc4f	354	blk_queue_logical_block_size(xpram_queues[i], 4096);
1da177e4 LT	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	* Setup device structures.
	366	*/
	367	offset = 0;
	368	for (i = 0; i < xpram_devs; i++) {
	369	struct gendisk *disk = xpram_disks[i];
	370
	371	xpram_devices[i].size = xpram_sizes[i] / 4;
	372	xpram_devices[i].offset = offset;
	373	offset += xpram_devices[i].size;
	374	disk->major = XPRAM_MAJOR;
	375	disk->first_minor = i;
	376	disk->fops = &xpram_devops;
	377	disk->private_data = &xpram_devices[i];
3ce66093	378	disk->queue = xpram_queues[i];
1da177e4	379	sprintf(disk->disk_name, "slram%d", i);
1da177e4 LT	380	set_capacity(disk, xpram_sizes[i] << 1);
	381	add_disk(disk);
	382	}
	383
	384	return 0;
1da177e4	385	out:
3ce66093 MS	386	while (i--) {
3ce66093 MS	387	blk_cleanup_queue(xpram_queues[i]);
1da177e4	388	put_disk(xpram_disks[i]);
3ce66093	389	}
1da177e4 LT	390	return rc;
	391	}
	392
14532095 MH	393	/*
	394	* Resume failed: Print error message and call panic.
	395	*/
	396	static void xpram_resume_error(const char *message)
	397	{
2c48c4d6	398	pr_err("Resuming the system failed: %s\n", message);
14532095 MH	399	panic("xpram resume error\n");
	400	}
	401
	402	/*
	403	* Check if xpram setup changed between suspend and resume.
	404	*/
	405	static int xpram_restore(struct device *dev)
	406	{
	407	if (!xpram_pages)
	408	return 0;
	409	if (xpram_present() != 0)
	410	xpram_resume_error("xpram disappeared");
	411	if (xpram_pages != xpram_highest_page_index() + 1)
	412	xpram_resume_error("Size of xpram changed");
14532095 MH	413	return 0;
	414	}
	415
47145210	416	static const struct dev_pm_ops xpram_pm_ops = {
14532095 MH	417	.restore = xpram_restore,
	418	};
	419
	420	static struct platform_driver xpram_pdrv = {
	421	.driver = {
	422	.name = XPRAM_NAME,
14532095 MH	423	.pm = &xpram_pm_ops,
	424	},
	425	};
	426
	427	static struct platform_device *xpram_pdev;
	428
1da177e4 LT	429	/*
	430	* Finally, the init/exit functions.
	431	*/
	432	static void __exit xpram_exit(void)
	433	{
	434	int i;
	435	for (i = 0; i < xpram_devs; i++) {
	436	del_gendisk(xpram_disks[i]);
3ce66093	437	blk_cleanup_queue(xpram_queues[i]);
1da177e4 LT	438	put_disk(xpram_disks[i]);
	439	}
	440	unregister_blkdev(XPRAM_MAJOR, XPRAM_NAME);
14532095 MH	441	platform_device_unregister(xpram_pdev);
14532095 MH	442	platform_driver_unregister(&xpram_pdrv);
1da177e4 LT	443	}
	444
	445	static int __init xpram_init(void)
	446	{
	447	int rc;
	448
	449	/* Find out size of expanded memory. */
	450	if (xpram_present() != 0) {
d1c2f892	451	pr_err("No expanded memory available\n");
1da177e4 LT	452	return -ENODEV;
1da177e4 LT	453	}
e620c494	454	xpram_pages = xpram_highest_page_index() + 1;
d1c2f892 MS	455	pr_info(" %u pages expanded memory found (%lu KB).\n",
d1c2f892 MS	456	xpram_pages, (unsigned long) xpram_pages*4);
1da177e4 LT	457	rc = xpram_setup_sizes(xpram_pages);
	458	if (rc)
	459	return rc;
14532095 MH	460	rc = platform_driver_register(&xpram_pdrv);
	461	if (rc)
	462	return rc;
	463	xpram_pdev = platform_device_register_simple(XPRAM_NAME, -1, NULL, 0);
	464	if (IS_ERR(xpram_pdev)) {
	465	rc = PTR_ERR(xpram_pdev);
	466	goto fail_platform_driver_unregister;
	467	}
	468	rc = xpram_setup_blkdev();
	469	if (rc)
	470	goto fail_platform_device_unregister;
	471	return 0;
	472
	473	fail_platform_device_unregister:
	474	platform_device_unregister(xpram_pdev);
	475	fail_platform_driver_unregister:
	476	platform_driver_unregister(&xpram_pdrv);
	477	return rc;
1da177e4 LT	478	}
	479
	480	module_init(xpram_init);
	481	module_exit(xpram_exit);