[PATCH] s390: 64 bit diag250 support

config DASD_DIAG

	tristate "Support for DIAG access to Disks"

	depends on DASD && ARCH_S390X = 'n'

	depends on DASD && ( ARCH_S390X = 'n' || EXPERIMENTAL)

	help

	  Select this option if you want to use Diagnose250 command to access

	  Disks under VM.  If you are not running under VM or unsure what it is,

 * Bugreports.to..: <Linux390@de.ibm.com>

 * (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999,2000

 *

 * $Revision: 1.42 $

 * $Revision: 1.49 $

 */

#include <linux/config.h>

#include <linux/stddef.h>

#include <linux/kernel.h>

#include <linux/slab.h>

#include <linux/hdreg.h>	/* HDIO_GETGEO			    */

#include <linux/hdreg.h>

#include <linux/bio.h>

#include <linux/module.h>

#include <linux/init.h>

#include <linux/jiffies.h>

#include <asm/dasd.h>

#include <asm/debug.h>

#include "dasd_int.h"

#include "dasd_diag.h"

#ifdef PRINTK_HEADER

#undef PRINTK_HEADER

#endif				/* PRINTK_HEADER */

#define PRINTK_HEADER "dasd(diag):"

MODULE_LICENSE("GPL");

/* The maximum number of blocks per request (max_blocks) is dependent on the

 * amount of storage that is available in the static I/O buffer for each

 * device. Currently each device gets 2 pages. We want to fit two requests

 * into the available memory so that we can immediately start the next if one

 * finishes. */

#define DIAG_MAX_BLOCKS	(((2 * PAGE_SIZE - sizeof(struct dasd_ccw_req) - \

			   sizeof(struct dasd_diag_req)) / \

		           sizeof(struct dasd_diag_bio)) / 2)

#define DIAG_MAX_RETRIES	32

#define DIAG_TIMEOUT		50 * HZ

struct dasd_discipline dasd_diag_discipline;

struct dasd_diag_private {

	struct dasd_diag_characteristics rdc_data;

	struct dasd_diag_rw_io iob;

	struct dasd_diag_init_io iib;

	unsigned int pt_block;

	blocknum_t pt_block;

};

struct dasd_diag_req {

	int block_count;

	unsigned int block_count;

	struct dasd_diag_bio bio[0];

};

static const u8 DASD_DIAG_CMS1[] = { 0xc3, 0xd4, 0xe2, 0xf1 };/* EBCDIC CMS1 */

/* Perform DIAG250 call with block I/O parameter list iob (input and output)

 * and function code cmd.

 * In case of an exception return 3. Otherwise return result of bitwise OR of

 * resulting condition code and DIAG return code. */

static __inline__ int

dia250(void *iob, int cmd)

{

	typedef struct {

		char _[max(sizeof (struct dasd_diag_init_io),

			   sizeof (struct dasd_diag_rw_io))];

	} addr_type;

	int rc;

	__asm__ __volatile__("    lhi   %0,3\n"

			     "	  lr	0,%2\n"

			     "	  diag	0,%1,0x250\n"

	__asm__ __volatile__(

#ifdef CONFIG_ARCH_S390X

		"	lghi	%0,3\n"

		"	lgr	0,%3\n"

		"	diag	0,%2,0x250\n"

		"0:	ipm	%0\n"

		"	srl	%0,28\n"

		"	or	%0,1\n"

		"1:\n"

#ifndef CONFIG_ARCH_S390X

		".section __ex_table,\"a\"\n"

			     "	  .align 4\n"

			     "	  .long 0b,1b\n"

		"	.align 8\n"

		"	.quad  0b,1b\n"

		".previous\n"

#else

		"	lhi	%0,3\n"

		"	lr	0,%3\n"

		"	diag	0,%2,0x250\n"

		"0:	ipm	%0\n"

		"	srl	%0,28\n"

		"	or	%0,1\n"

		"1:\n"

		".section __ex_table,\"a\"\n"

			     "	  .align 8\n"

			     "	  .quad  0b,1b\n"

		"	.align 4\n"

		"	.long 0b,1b\n"

		".previous\n"

#endif

			     : "=&d" (rc)

			     : "d" (cmd), "d" ((void *) __pa(iob))

		: "=&d" (rc), "=m" (*(addr_type *) iob)

		: "d" (cmd), "d" (iob), "m" (*(addr_type *) iob)

		: "0", "1", "cc");

	return rc;

}

/* Initialize block I/O to DIAG device using the specified blocksize and

 * block offset. On success, return zero and set end_block to contain the

 * number of blocks on the device minus the specified offset. Return non-zero

 * otherwise. */

static __inline__ int

mdsk_init_io(struct dasd_device * device, int blocksize, int offset, int size)

mdsk_init_io(struct dasd_device *device, unsigned int blocksize,

	     blocknum_t offset, blocknum_t *end_block)

{

	struct dasd_diag_private *private;

	struct dasd_diag_init_io *iib;

	iib->dev_nr = _ccw_device_get_device_number(device->cdev);

	iib->block_size = blocksize;

	iib->offset = offset;

	iib->start_block = 0;

	iib->end_block = size;

	iib->flaga = DASD_DIAG_FLAGA_DEFAULT;

	rc = dia250(iib, INIT_BIO);

	return rc & 3;

	if ((rc & 3) == 0 && end_block)

		*end_block = iib->end_block;

	return rc;

}

/* Remove block I/O environment for device. Return zero on success, non-zero

 * otherwise. */

static __inline__ int

mdsk_term_io(struct dasd_device * device)

{

	memset(iib, 0, sizeof (struct dasd_diag_init_io));

	iib->dev_nr = _ccw_device_get_device_number(device->cdev);

	rc = dia250(iib, TERM_BIO);

	return rc & 3;

	return rc;

}

/* Error recovery for failed DIAG requests - try to reestablish the DIAG

 * environment. */

static void

dasd_diag_erp(struct dasd_device *device)

{

	int rc;

	mdsk_term_io(device);

	rc = mdsk_init_io(device, device->bp_block, 0, NULL);

	if (rc)

		DEV_MESSAGE(KERN_WARNING, device, "DIAG ERP unsuccessful, "

			    "rc=%d", rc);

}

/* Start a given request at the device. Return zero on success, non-zero

 * otherwise. */

static int

dasd_start_diag(struct dasd_ccw_req * cqr)

{

	int rc;

	device = cqr->device;

	if (cqr->retries < 0) {

		DEV_MESSAGE(KERN_WARNING, device, "DIAG start_IO: request %p "

			    "- no retry left)", cqr);

		cqr->status = DASD_CQR_FAILED;

		return -EIO;

	}

	private = (struct dasd_diag_private *) device->private;

	dreq = (struct dasd_diag_req *) cqr->data;

	private->iob.dev_nr = _ccw_device_get_device_number(device->cdev);

	private->iob.key = 0;

	private->iob.flags = 2;	/* do asynchronous io */

	private->iob.flags = DASD_DIAG_RWFLAG_ASYNC;

	private->iob.block_count = dreq->block_count;

	private->iob.interrupt_params = (u32)(addr_t) cqr;

	private->iob.interrupt_params = (addr_t) cqr;

	private->iob.bio_list = __pa(dreq->bio);

	private->iob.flaga = DASD_DIAG_FLAGA_DEFAULT;

	cqr->startclk = get_clock();

	cqr->starttime = jiffies;

	cqr->retries--;

	rc = dia250(&private->iob, RW_BIO);

	if (rc > 8) {

		DEV_MESSAGE(KERN_WARNING, device, "dia250 returned CC %d", rc);

		cqr->status = DASD_CQR_ERROR;

	} else if (rc == 0) {

	switch (rc) {

	case 0: /* Synchronous I/O finished successfully */

		cqr->stopclk = get_clock();

		cqr->status = DASD_CQR_DONE;

		dasd_schedule_bh(device);

	} else {

		/* Indicate to calling function that only a dasd_schedule_bh()

		   and no timer is needed */

                rc = -EACCES;

		break;

	case 8: /* Asynchronous I/O was started */

		cqr->status = DASD_CQR_IN_IO;

		rc = 0;

		break;

	default: /* Error condition */

		cqr->status = DASD_CQR_QUEUED;

		DEV_MESSAGE(KERN_WARNING, device, "dia250 returned rc=%d", rc);

		dasd_diag_erp(device);

		rc = -EIO;

		break;

	}

	return rc;

}

/* Terminate given request at the device. */

static int

dasd_diag_term_IO(struct dasd_ccw_req * cqr)

{

	struct dasd_device *device;

	device = cqr->device;

	mdsk_term_io(device);

	mdsk_init_io(device, device->bp_block, 0, NULL);

	cqr->status = DASD_CQR_CLEAR;

	cqr->stopclk = get_clock();

	dasd_schedule_bh(device);

	return 0;

}

/* Handle external interruption. */

static void

dasd_ext_handler(struct pt_regs *regs, __u16 code)

{

	struct dasd_device *device;

	unsigned long long expires;

	unsigned long flags;

	char status;

	int ip;

	u8 int_code, status;

	addr_t ip;

	int rc;

	/*

	 * Get the external interruption subcode. VM stores

	 * this in the 'cpu address' field associated with

	 * the external interrupt. For diag 250 the subcode

	 * needs to be 3.

	 */

	if ((S390_lowcore.cpu_addr & 0xff00) != 0x0300)

	int_code = *((u8 *) DASD_DIAG_LC_INT_CODE);

	status = *((u8 *) DASD_DIAG_LC_INT_STATUS);

	switch (int_code) {

	case DASD_DIAG_CODE_31BIT:

		ip = (addr_t) *((u32 *) DASD_DIAG_LC_INT_PARM_31BIT);

		break;

	case DASD_DIAG_CODE_64BIT:

		ip = (addr_t) *((u64 *) DASD_DIAG_LC_INT_PARM_64BIT);

		break;

	default:

		return;

	status = *((char *) &S390_lowcore.ext_params + 5);

	ip = S390_lowcore.ext_params;

	}

	if (!ip) {		/* no intparm: unsolicited interrupt */

		MESSAGE(KERN_DEBUG, "%s", "caught unsolicited interrupt");

		return;

	}

	cqr = (struct dasd_ccw_req *)(addr_t) ip;

	cqr = (struct dasd_ccw_req *) ip;

	device = (struct dasd_device *) cqr->device;

	if (strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {

		DEV_MESSAGE(KERN_WARNING, device,

	/* get irq lock to modify request queue */

	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);

	/* Check for a pending clear operation */

	if (cqr->status == DASD_CQR_CLEAR) {

		cqr->status = DASD_CQR_QUEUED;

		dasd_clear_timer(device);

		dasd_schedule_bh(device);

		spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);

		return;

	}

	cqr->stopclk = get_clock();

	expires = 0;

			next = list_entry(device->ccw_queue.next,

					  struct dasd_ccw_req, list);

			if (next->status == DASD_CQR_QUEUED) {

				if (dasd_start_diag(next) == 0)

				rc = dasd_start_diag(next);

				if (rc == 0)

					expires = next->expires;

				else

				else if (rc != -EACCES)

					DEV_MESSAGE(KERN_WARNING, device, "%s",

						    "Interrupt fastpath "

						    "failed!");

			}

		}

	} else 

		cqr->status = DASD_CQR_FAILED;

	} else {

		cqr->status = DASD_CQR_QUEUED;

		DEV_MESSAGE(KERN_WARNING, device, "interrupt status for "

			    "request %p was %d (%d retries left)", cqr, status,

			    cqr->retries);

		dasd_diag_erp(device);

	}

	if (expires != 0)

		dasd_set_timer(device, expires);

	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);

}

/* Check whether device can be controlled by DIAG discipline. Return zero on

 * success, non-zero otherwise. */

static int

dasd_diag_check_device(struct dasd_device *device)

{

	struct dasd_diag_private *private;

	struct dasd_diag_characteristics *rdc_data;

	struct dasd_diag_bio bio;

	long *label;

	int sb, bsize;

	struct dasd_diag_cms_label *label;

	blocknum_t end_block;

	unsigned int sb, bsize;

	int rc;

	private = (struct dasd_diag_private *) device->private;

	rdc_data->rdc_len = sizeof (struct dasd_diag_characteristics);

	rc = diag210((struct diag210 *) rdc_data);

	if (rc)

	if (rc) {

		DEV_MESSAGE(KERN_WARNING, device, "failed to retrieve device "

			    "information (rc=%d)", rc);

		return -ENOTSUPP;

	}

	/* Figure out position of label block */

	switch (private->rdc_data.vdev_class) {

		private->pt_block = 2;

		break;

	default:

		DEV_MESSAGE(KERN_WARNING, device, "unsupported device class "

			    "(class=%d)", private->rdc_data.vdev_class);

		return -ENOTSUPP;

	}

	mdsk_term_io(device);

	/* figure out blocksize of device */

	label = (long *) get_zeroed_page(GFP_KERNEL);

	label = (struct dasd_diag_cms_label *) get_zeroed_page(GFP_KERNEL);

	if (label == NULL)  {

		DEV_MESSAGE(KERN_WARNING, device, "%s",

			    "No memory to allocate initialization request");

		return -ENOMEM;

	}

	rc = 0;

	end_block = 0;

	/* try all sizes - needed for ECKD devices */

	for (bsize = 512; bsize <= PAGE_SIZE; bsize <<= 1) {

		mdsk_init_io(device, bsize, 0, 64);

		mdsk_init_io(device, bsize, 0, &end_block);

		memset(&bio, 0, sizeof (struct dasd_diag_bio));

		bio.type = MDSK_READ_REQ;

		bio.block_number = private->pt_block + 1;

		private->iob.block_count = 1;

		private->iob.interrupt_params = 0;

		private->iob.bio_list = __pa(&bio);

		if (dia250(&private->iob, RW_BIO) == 0)

		private->iob.flaga = DASD_DIAG_FLAGA_DEFAULT;

		rc = dia250(&private->iob, RW_BIO);

		if (rc == 0 || rc == 3)

			break;

		mdsk_term_io(device);

	}

	if (bsize <= PAGE_SIZE && label[0] == 0xc3d4e2f1) {

	if (rc == 3) {

		DEV_MESSAGE(KERN_WARNING, device, "%s", "DIAG call failed");

		rc = -EOPNOTSUPP;

	} else if (rc != 0) {

		DEV_MESSAGE(KERN_WARNING, device, "device access failed "

			    "(rc=%d)", rc);

		rc = -EIO;

	} else {

		if (memcmp(label->label_id, DASD_DIAG_CMS1,

			  sizeof(DASD_DIAG_CMS1)) == 0) {

			/* get formatted blocksize from label block */

		bsize = (int) label[3];

		device->blocks = label[7];

			bsize = (unsigned int) label->block_size;

			device->blocks = (unsigned long) label->block_count;

		} else

			device->blocks = end_block;

		device->bp_block = bsize;

		device->s2b_shift = 0;	/* bits to shift 512 to get a block */

		for (sb = 512; sb < bsize; sb = sb << 1)

			device->s2b_shift++;

		DEV_MESSAGE(KERN_INFO, device,

			    "capacity (%dkB blks): %ldkB",

			    (device->bp_block >> 10),

			    (device->blocks << device->s2b_shift) >> 1);

			    "(%ld B/blk): %ldkB",

			    (unsigned long) device->bp_block,

			    (unsigned long) (device->blocks <<

				device->s2b_shift) >> 1);

		rc = 0;

	} else {

		if (bsize > PAGE_SIZE)

			DEV_MESSAGE(KERN_WARNING, device, "%s",

				    "DIAG access failed");

		else

			DEV_MESSAGE(KERN_WARNING, device, "%s",

				    "volume is not CMS formatted");

		rc = -EMEDIUMTYPE;

	}

	free_page((long) label);

	return rc;

}

/* Fill in virtual disk geometry for device. Return zero on success, non-zero

 * otherwise. */

static int

dasd_diag_fill_geometry(struct dasd_device *device, struct hd_geometry *geo)

{

	return dasd_default_erp_postaction;

}

/* Create DASD request from block device request. Return pointer to new

 * request on success, ERR_PTR otherwise. */

static struct dasd_ccw_req *

dasd_diag_build_cp(struct dasd_device * device, struct request *req)

{

	struct bio *bio;

	struct bio_vec *bv;

	char *dst;

	int count, datasize;

	unsigned int count, datasize;

	sector_t recid, first_rec, last_rec;

	unsigned blksize, off;

	unsigned int blksize, off;

	unsigned char rw_cmd;

	int i;

			}

		}

	}

	cqr->retries = DIAG_MAX_RETRIES;

	cqr->buildclk = get_clock();

	cqr->device = device;

	cqr->expires = 50 * HZ;	/* 50 seconds */

	cqr->expires = DIAG_TIMEOUT;

	cqr->status = DASD_CQR_FILLED;

	return cqr;

}

/* Release DASD request. Return non-zero if request was successful, zero

 * otherwise. */

static int

dasd_diag_free_cp(struct dasd_ccw_req *cqr, struct request *req)

{

	return status;

}

/* Fill in IOCTL data for device. */

static int

dasd_diag_fill_info(struct dasd_device * device,

		    struct dasd_information2_t * info)

	struct dasd_diag_private *private;

	private = (struct dasd_diag_private *) device->private;

	info->label_block = private->pt_block;

	info->label_block = (unsigned int) private->pt_block;

	info->FBA_layout = 1;

	info->format = DASD_FORMAT_LDL;

	info->characteristics_size = sizeof (struct dasd_diag_characteristics);

		    "dump sense not available for DIAG data");

}

/*

 * max_blocks is dependent on the amount of storage that is available

 * in the static io buffer for each device. Currently each device has

 * 8192 bytes (=2 pages). dasd diag is only relevant for 31 bit.

 * The struct dasd_ccw_req has 96 bytes, the struct dasd_diag_req has

 * 8 bytes and the struct dasd_diag_bio for each block has 16 bytes. 

 * That makes:

 * (8192 - 96 - 8) / 16 = 505.5 blocks at maximum.

 * We want to fit two into the available memory so that we can immediately

 * start the next request if one finishes off. That makes 252.75 blocks

 * for one request. Give a little safety and the result is 240.

 */

struct dasd_discipline dasd_diag_discipline = {

	.owner = THIS_MODULE,

	.name = "DIAG",

	.ebcname = "DIAG",

	.max_blocks = 240,

	.max_blocks = DIAG_MAX_BLOCKS,

	.check_device = dasd_diag_check_device,

	.fill_geometry = dasd_diag_fill_geometry,

	.start_IO = dasd_start_diag,

	.term_IO = dasd_diag_term_IO,

	.examine_error = dasd_diag_examine_error,

	.erp_action = dasd_diag_erp_action,

	.erp_postaction = dasd_diag_erp_postaction,

			    "Machine is not VM: %s "

			    "discipline not initializing",

			    dasd_diag_discipline.name);

		return -EINVAL;

		return -ENODEV;

	}

	ASCEBC(dasd_diag_discipline.ebcname, 4);

static void __exit

dasd_diag_cleanup(void)

{

	if (!MACHINE_IS_VM) {

		MESSAGE_LOG(KERN_INFO,

			    "Machine is not VM: %s "

			    "discipline not cleaned",

			    dasd_diag_discipline.name);

		return;

	}

	unregister_external_interrupt(0x2603, dasd_ext_handler);

	ctl_clear_bit(0, 9);

	dasd_diag_discipline_pointer = NULL;

module_init(dasd_diag_init);

module_exit(dasd_diag_cleanup);

/*

 * Overrides for Emacs so that we follow Linus's tabbing style.

 * Emacs will notice this stuff at the end of the file and automatically

 * adjust the settings for this buffer only.  This must remain at the end

 * of the file.

 * ---------------------------------------------------------------------------

 * Local variables:

 * c-indent-level: 4 

 * c-brace-imaginary-offset: 0

 * c-brace-offset: -4

 * c-argdecl-indent: 4

 * c-label-offset: -4

 * c-continued-statement-offset: 4

 * c-continued-brace-offset: 0

 * indent-tabs-mode: 1

 * tab-width: 8

 * End:

 */

 * Bugreports.to..: <Linux390@de.ibm.com>

 * (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999,2000

 *

 * $Revision: 1.6 $

 * $Revision: 1.7 $

 */

#define MDSK_WRITE_REQ 0x01

#define DEV_CLASS_FBA	0x01

#define DEV_CLASS_ECKD	0x04

#define DASD_DIAG_LC_INT_CODE		132

#define DASD_DIAG_LC_INT_STATUS		133

#define DASD_DIAG_LC_INT_PARM_31BIT	128

#define DASD_DIAG_LC_INT_PARM_64BIT	4536

#define DASD_DIAG_CODE_31BIT		0x03

#define DASD_DIAG_CODE_64BIT		0x07

#define DASD_DIAG_RWFLAG_ASYNC		0x02

#define DASD_DIAG_RWFLAG_NOCACHE	0x01

#define DASD_DIAG_FLAGA_FORMAT_64BIT	0x80

struct dasd_diag_characteristics {

	u16 dev_nr;

	u16 rdc_len;

	u8 rdev_features;

} __attribute__ ((packed, aligned(4)));

struct dasd_diag_cms_label {

	u8 label_id[4];

	u8 vol_id[6];

	u16 version_id;

	u32 block_size;

	u32 origin_ptr;

	u32 usable_count;

	u32 formatted_count;

	u32 block_count;

	u32 used_count;

	u32 fst_size;

	u32 fst_count;

	u8 format_date[6];

	u8 reserved1[2];

	u32 disk_offset;

	u32 map_block;

	u32 hblk_disp;

	u32 user_disp;

	u8 reserved2[4];

	u8 segment_name[8];

} __attribute__ ((packed));

#ifdef CONFIG_ARCH_S390X

#define DASD_DIAG_FLAGA_DEFAULT		DASD_DIAG_FLAGA_FORMAT_64BIT

typedef u64 blocknum_t;

typedef s64 sblocknum_t;

struct dasd_diag_bio {

	u8 type;

	u8 status;

	u8 spare1[2];

	u32 alet;

	blocknum_t block_number;

	u64 buffer;

} __attribute__ ((packed, aligned(8)));

struct dasd_diag_init_io {

	u16 dev_nr;

	u8 flaga;

	u8 spare1[21];

	u32 block_size;

	u8 spare2[4];

	blocknum_t offset;