// SPDX-License-Identifier: GPL-2.0
/*
* Author(s)......: Holger Smolinski <[email protected]>
* Based on.......: linux/drivers/s390/block/mdisk.c
* ...............: by Hartmunt Penner <[email protected]>
* Bugreports.to..: <[email protected]>
* Copyright IBM Corp. 1999, 2000
*
*/
#include <linux/kernel_stat.h>
#include <linux/stddef.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/hdreg.h>
#include <linux/bio.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/jiffies.h>
#include <asm/asm-extable.h>
#include <asm/dasd.h>
#include <asm/debug.h>
#include <asm/diag.h>
#include <asm/ebcdic.h>
#include <linux/io.h>
#include <asm/irq.h>
#include <asm/vtoc.h>
#include "dasd_int.h"
#include "dasd_diag.h"
MODULE_DESCRIPTION("S/390 Support for DIAG access to DASD Disks");
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
static 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;
blocknum_t pt_block;
struct ccw_dev_id dev_id;
};
struct dasd_diag_req {
unsigned int block_count;
struct dasd_diag_bio bio[];
};
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)
{
union register_pair rx = { .even = (unsigned long)iob, };
typedef union {
struct dasd_diag_init_io init_io;
struct dasd_diag_rw_io rw_io;
} addr_type;
int cc;
cc = 3;
asm volatile(
" diag %[rx],%[cmd],0x250\n"
"0: ipm %[cc]\n"
" srl %[cc],28\n"
"1:\n"
EX_TABLE(0b,1b)
: [cc] "+&d" (cc), [rx] "+&d" (rx.pair), "+m" (*(addr_type *)iob)
: [cmd] "d" (cmd)
: "cc");
return cc | rx.odd;
}
static inline int dia250(void *iob, int cmd)
{
diag_stat_inc(DIAG_STAT_X250);
return __dia250(iob, cmd);
}
/* 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, unsigned int blocksize,
blocknum_t offset, blocknum_t *end_block)
{
struct dasd_diag_private *private = device->private;
struct dasd_diag_init_io *iib = &private->iib;
int rc;
memset(iib, 0, sizeof (struct dasd_diag_init_io));
iib->dev_nr = private->dev_id.devno;
iib->block_size = blocksize;
iib->offset = offset;
iib->flaga = DASD_DIAG_FLAGA_DEFAULT;
rc = dia250(iib, INIT_BIO);
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)
{
struct dasd_diag_private *private = device->private;
struct dasd_diag_init_io *iib = &private->iib;
int rc;
memset(iib, 0, sizeof (struct dasd_diag_init_io));
iib->dev_nr = private->dev_id.devno;
rc = dia250(iib, TERM_BIO);
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->block->bp_block, 0, NULL);
if (rc == 4) {
if (!(test_and_set_bit(DASD_FLAG_DEVICE_RO, &device->flags)))
pr_warn("%s: The access mode of a DIAG device changed to read-only\n",
dev_name(&device->cdev->dev));
rc = 0;
}
if (rc)
pr_warn("%s: DIAG ERP failed with rc=%d\n",
dev_name(&device->cdev->dev), 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)
{
struct dasd_device *device;
struct dasd_diag_private *private;
struct dasd_diag_req *dreq;
int rc;
device = cqr->startdev;
if (cqr->retries < 0) {
DBF_DEV_EVENT(DBF_ERR, device, "DIAG start_IO: request %p "
"- no retry left)", cqr);
cqr->status = DASD_CQR_ERROR;
return -EIO;
}
private = device->private;
dreq = cqr->data;
private->iob.dev_nr = private->dev_id.devno;
private->iob.key = 0;
private->iob.flags = DASD_DIAG_RWFLAG_ASYNC;
private->iob.block_count = dreq->block_count;
private->iob.interrupt_params = (addr_t) cqr;
private->iob.bio_list = dreq->bio;
private->iob.flaga = DASD_DIAG_FLAGA_DEFAULT;
cqr->startclk = get_tod_clock();
cqr->starttime = jiffies;
cqr->retries--;
rc = dia250(&private->iob, RW_BIO);
switch (rc) {
case 0: /* Synchronous I/O finished successfully */
cqr->stopclk = get_tod_clock();
cqr->status = DASD_CQR_SUCCESS;
/* 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;
DBF_DEV_EVENT(DBF_WARNING, device, "dia250 returned rc=%d", rc);
dasd_diag_erp(device);
rc = -EIO;
break;
}
cqr->intrc = rc;
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->startdev;
mdsk_term_io(device);
mdsk_init_io(device, device->block->bp_block, 0, NULL);
cqr->status = DASD_CQR_CLEAR_PENDING;
cqr->stopclk = get_tod_clock();
dasd_schedule_device_bh(device);
return 0;
}
/* Handle external interruption. */
static void dasd_ext_handler(struct ext_code ext_code,
unsigned int param32, unsigned long param64)
{
struct dasd_ccw_req *cqr, *next;
struct dasd_device *device;
unsigned long expires;
unsigned long flags;
addr_t ip;
int rc;
switch (ext_code.subcode >> 8) {
case DASD_DIAG_CODE_31BIT:
ip = (addr_t) param32;
break;
case DASD_DIAG_CODE_64BIT:
ip = (addr_t) param64;
break;
default:
return;
}
inc_irq_stat(IRQEXT_DSD);
if (!ip) { /* no intparm: unsolicited interrupt */
DBF_EVENT(DBF_NOTICE, "%s", "caught unsolicited "
"interrupt");
return;
}
cqr = (struct dasd_ccw_req *) ip;
device = (struct dasd_device *) cqr->startdev;
if (strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
DBF_DEV_EVENT(DBF_WARNING, device,
" magic number of dasd_ccw_req 0x%08X doesn't"
" match discipline 0x%08X",
cqr->magic, *(int *) (&device->discipline->name));
return;
}
/* 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_PENDING) {
cqr->status = DASD_CQR_CLEARED;
dasd_device_clear_timer(device);
dasd_schedule_device_bh(device);
spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
return;
}
cqr->stopclk = get_tod_clock();
expires = 0;
if ((ext_code.subcode & 0xff) == 0) {
cqr->status = DASD_CQR_SUCCESS;
/* Start first request on queue if possible -> fast_io. */
if (!list_empty(&device->ccw_queue)) {
next = list_entry(device->ccw_queue.next,
struct dasd_ccw_req, devlist);
if (next->status == DASD_CQR_QUEUED) {
rc = dasd_start_diag(next);
if (rc == 0)
expires = next->expires;
}
}
} else {
cqr->status = DASD_CQR_QUEUED;
DBF_DEV_EVENT(DBF_DEBUG, device, "interrupt status for "
"request %p was %d (%d retries left)", cqr,
ext_code.subcode & 0xff, cqr->retries);
dasd_diag_erp(device);
}
if (expires != 0)
dasd_device_set_timer(device, expires);
else
dasd_device_clear_timer(device);
dasd_schedule_device_bh(device);
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 = device->private;
struct dasd_diag_characteristics *rdc_data;
struct vtoc_cms_label *label;
struct dasd_block *block;
struct dasd_diag_bio *bio;
unsigned int sb, bsize;
blocknum_t end_block;
int rc;
if (private == NULL) {
private = kzalloc(sizeof(*private), GFP_KERNEL);
if (private == NULL) {
DBF_DEV_EVENT(DBF_WARNING, device, "%s",
"Allocating memory for private DASD data "
"failed\n");
return -ENOMEM;
}
ccw_device_get_id(device->cdev, &private->dev_id);
device->private = private;
}
block = dasd_alloc_block();
if (IS_ERR(block)) {
DBF_DEV_EVENT(DBF_WARNING, device, "%s",
"could not allocate dasd block structure");
device->private = NULL;
kfree(private);
return PTR_ERR(block);
}
device->block = block;
block->base = device;
/* Read Device Characteristics */
rdc_data = &private->rdc_data;
rdc_data->dev_nr = private->dev_id.devno;
rdc_data->rdc_len = sizeof (struct dasd_diag_characteristics);
rc = diag210((struct diag210 *) rdc_data);
if (rc) {
DBF_DEV_EVENT(DBF_WARNING, device, "failed to retrieve device "
"information (rc=%d)", rc);
rc = -EOPNOTSUPP;
goto out;
}
device->default_expires = DIAG_TIMEOUT;
device->default_retries = DIAG_MAX_RETRIES;
/* Figure out position of label block */
switch (private->rdc_data.vdev_class) {
case DEV_CLASS_FBA:
private->pt_block = 1;
break;
case DEV_CLASS_ECKD:
private->pt_block = 2;
break;
default:
pr_warn("%s: Device type %d is not supported in DIAG mode\n",
dev_name(&device->cdev->dev),
private->rdc_data.vdev_class);
rc = -EOPNOTSUPP;
goto out;
}
DBF_DEV_EVENT(DBF_INFO, device,
"%04X: %04X on real %04X/%02X",
rdc_data->dev_nr,
rdc_data->vdev_type,
rdc_data->rdev_type, rdc_data->rdev_model);
/* terminate all outstanding operations */
mdsk_term_io(device);
/* figure out blocksize of device */
label = (struct vtoc_cms_label *) get_zeroed_page(GFP_KERNEL);
if (label == NULL) {
DBF_DEV_EVENT(DBF_WARNING, device, "%s",
"No memory to allocate initialization request");
rc = -ENOMEM;
goto out;
}
bio = kzalloc(sizeof(*bio), GFP_KERNEL);
if (bio == NULL) {
DBF_DEV_EVENT(DBF_WARNING, device, "%s",
"No memory to allocate initialization bio");
rc = -ENOMEM;
goto out_label;
}
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, &end_block);
memset(bio, 0, sizeof(*bio));
bio->type = MDSK_READ_REQ;
bio->block_number = private->pt_block + 1;
bio->buffer = label;
memset(&private->iob, 0, sizeof (struct dasd_diag_rw_io));
private->iob.dev_nr = rdc_data->dev_nr;
private->iob.key = 0;
private->iob.flags = 0; /* do synchronous io */
private->iob.block_count = 1;
private->iob.interrupt_params = 0;
private->iob.bio_list = bio;
private->iob.flaga = DASD_DIAG_FLAGA_DEFAULT;
rc = dia250(&private->iob, RW_BIO);
if (rc == 3) {
pr_warn("%s: A 64-bit DIAG call failed\n",
dev_name(&device->cdev->dev));
rc = -EOPNOTSUPP;
goto out_bio;
}
mdsk_term_io(device);
if (rc == 0)
break;
}
if (bsize > PAGE_SIZE) {
pr_warn("%s: Accessing the DASD failed because of an incorrect format (rc=%d)\n",
dev_name(&device->cdev->dev), rc);
rc = -EIO;
goto out_bio;
}
/* check for label block */
if (memcmp(label->label_id, DASD_DIAG_CMS1,
sizeof(DASD_DIAG_CMS1)) == 0) {
/* get formatted blocksize from label block */
bsize = (unsigned int) label->block_size;
block->blocks = (unsigned long) label->block_count;
} else
block->blocks = end_block;
block->bp_block = bsize;
block->s2b_shift = 0; /* bits to shift 512 to get a block */
for (sb = 512; sb < bsize; sb = sb << 1)
block->s2b_shift++;
rc = mdsk_init_io(device, block->bp_block, 0, NULL);
if (rc && (rc != 4)) {
pr_warn("%s: DIAG initialization failed with rc=%d\n",
dev_name(&device->cdev->dev), rc);
rc = -EIO;
} else {
if (rc == 4)
set_bit(DASD_FLAG_DEVICE_RO, &device->flags);
pr_info("%s: New DASD with %ld byte/block, total size %ld "
"KB%s\n", dev_name(&device->cdev->dev),
(unsigned long) block->bp_block,
(unsigned long) (block->blocks <<
block->s2b_shift) >> 1,
(rc == 4) ? ", read-only device" : "");
rc = 0;
}
out_bio:
kfree(bio);
out_label:
free_page((long) label);
out:
if (rc) {
device->block = NULL;
dasd_free_block(block);
device->private = NULL;
kfree(private);
}
return rc;
}
/* Fill in virtual disk geometry for device. Return zero on success, non-zero
* otherwise. */
static int
dasd_diag_fill_geometry(struct dasd_block *block, struct hd_geometry *geo)
{
if (dasd_check_blocksize(block->bp_block) != 0)
return -EINVAL;
geo->cylinders = (block->blocks << block->s2b_shift) >> 10;
geo->heads = 16;
geo->sectors = 128 >> block->s2b_shift;
return 0;
}
static dasd_erp_fn_t
dasd_diag_erp_action(struct dasd_ccw_req * cqr)
{
return dasd_default_erp_action;
}
static dasd_erp_fn_t
dasd_diag_erp_postaction(struct dasd_ccw_req * cqr)
{
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 *memdev,
struct dasd_block *block,
struct request *req)
{
struct dasd_ccw_req *cqr;
struct dasd_diag_req *dreq;
struct dasd_diag_bio *dbio;
struct req_iterator iter;
struct bio_vec bv;
char *dst;
unsigned int count;
sector_t recid, first_rec, last_rec;
unsigned int blksize, off;
unsigned char rw_cmd;
if (rq_data_dir(req) == READ)
rw_cmd = MDSK_READ_REQ;
else if (rq_data_dir(req) == WRITE)
rw_cmd = MDSK_WRITE_REQ;
else
return ERR_PTR(-EINVAL);
blksize = block->bp_block;
/* Calculate record id of first and last block. */
first_rec = blk_rq_pos(req) >> block->s2b_shift;
last_rec =
(blk_rq_pos(req) + blk_rq_sectors(req) - 1) >> block->s2b_shift;
/* Check struct bio and count the number of blocks for the request. */
count = 0;
rq_for_each_segment(bv, req, iter) {
if (bv.bv_len & (blksize - 1))
/* Fba can only do full blocks. */
return ERR_PTR(-EINVAL);
count += bv.bv_len >> (block->s2b_shift + 9);
}
/* Paranoia. */
if (count != last_rec - first_rec + 1)
return ERR_PTR(-EINVAL);
/* Build the request */
cqr = dasd_smalloc_request(DASD_DIAG_MAGIC, 0, struct_size(dreq, bio, count),
memdev, blk_mq_rq_to_pdu(req));
if (IS_ERR(cqr))
return cqr;
dreq = (struct dasd_diag_req *) cqr->data;
dreq->block_count = count;
dbio = dreq->bio;
recid = first_rec;
rq_for_each_segment(bv, req, iter) {
dst = bvec_virt(&bv);
for (off = 0; off < bv.bv_len; off += blksize) {
memset(dbio, 0, sizeof (struct dasd_diag_bio));
dbio->type = rw_cmd;
dbio->block_number = recid + 1;
dbio->buffer = dst;
dbio++;
dst += blksize;
recid++;
}
}
cqr->retries = memdev->default_retries;
cqr->buildclk = get_tod_clock();
if (blk_noretry_request(req) ||
block->base->features & DASD_FEATURE_FAILFAST)
set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags);
cqr->startdev = memdev;
cqr->memdev = memdev;
cqr->block = block;
cqr->expires = memdev->default_expires * HZ;
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)
{
int status;
status = cqr->status == DASD_CQR_DONE;
dasd_sfree_request(cqr, cqr->memdev);
return status;
}
static void dasd_diag_handle_terminated_request(struct dasd_ccw_req *cqr)
{
if (cqr->retries < 0)
cqr->status = DASD_CQR_FAILED;
else
cqr->status = DASD_CQR_FILLED;
};
/* 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 = device->private;
info->label_block = (unsigned int) private->pt_block;
info->FBA_layout = 1;
info->format = DASD_FORMAT_LDL;
info->characteristics_size = sizeof(private->rdc_data);
memcpy(info->characteristics, &private->rdc_data,
sizeof(private->rdc_data));
info->confdata_size = 0;
return 0;
}
static void
dasd_diag_dump_sense(struct dasd_device *device, struct dasd_ccw_req * req,
struct irb *stat)
{
DBF_DEV_EVENT(DBF_WARNING, device, "%s",
"dump sense not available for DIAG data");
}
static unsigned int dasd_diag_max_sectors(struct dasd_block *block)
{
return DIAG_MAX_BLOCKS << block->s2b_shift;
}
static int dasd_diag_pe_handler(struct dasd_device *device,
__u8 tbvpm, __u8 fcsecpm)
{
return dasd_generic_verify_path(device, tbvpm);
}
static struct dasd_discipline dasd_diag_discipline = {
.owner = THIS_MODULE,
.name = "DIAG",
.ebcname = "DIAG",
.max_sectors = dasd_diag_max_sectors,
.check_device = dasd_diag_check_device,
.pe_handler = dasd_diag_pe_handler,
.fill_geometry = dasd_diag_fill_geometry,
.start_IO = dasd_start_diag,
.term_IO = dasd_diag_term_IO,
.handle_terminated_request = dasd_diag_handle_terminated_request,
.erp_action = dasd_diag_erp_action,
.erp_postaction = dasd_diag_erp_postaction,
.build_cp = dasd_diag_build_cp,
.free_cp = dasd_diag_free_cp,
.dump_sense = dasd_diag_dump_sense,
.fill_info = dasd_diag_fill_info,
};
static int __init
dasd_diag_init(void)
{
if (!MACHINE_IS_VM) {
pr_info("Discipline %s cannot be used without z/VM\n",
dasd_diag_discipline.name);
return -ENODEV;
}
ASCEBC(dasd_diag_discipline.ebcname, 4);
irq_subclass_register(IRQ_SUBCLASS_SERVICE_SIGNAL);
register_external_irq(EXT_IRQ_CP_SERVICE, dasd_ext_handler);
dasd_diag_discipline_pointer = &dasd_diag_discipline;
return 0;
}
static void __exit
dasd_diag_cleanup(void)
{
unregister_external_irq(EXT_IRQ_CP_SERVICE, dasd_ext_handler);
irq_subclass_unregister(IRQ_SUBCLASS_SERVICE_SIGNAL);
dasd_diag_discipline_pointer = NULL;
}
module_init(dasd_diag_init);
module_exit(dasd_diag_cleanup);
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