// SPDX-License-Identifier: GPL-2.0
/*
* CCW device PGID and path verification I/O handling.
*
* Copyright IBM Corp. 2002, 2009
* Author(s): Cornelia Huck <[email protected]>
* Martin Schwidefsky <[email protected]>
* Peter Oberparleiter <[email protected]>
*/
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/bitops.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <asm/ccwdev.h>
#include <asm/cio.h>
#include "cio.h"
#include "cio_debug.h"
#include "device.h"
#include "io_sch.h"
#define PGID_RETRIES 256
#define PGID_TIMEOUT (10 * HZ)
static void verify_start(struct ccw_device *cdev);
/*
* Process path verification data and report result.
*/
static void verify_done(struct ccw_device *cdev, int rc)
{
struct subchannel *sch = to_subchannel(cdev->dev.parent);
struct ccw_dev_id *id = &cdev->private->dev_id;
int mpath = cdev->private->flags.mpath;
int pgroup = cdev->private->flags.pgroup;
if (rc)
goto out;
/* Ensure consistent multipathing state at device and channel. */
if (sch->config.mp != mpath) {
sch->config.mp = mpath;
rc = cio_commit_config(sch);
}
out:
CIO_MSG_EVENT(2, "vrfy: device 0.%x.%04x: rc=%d pgroup=%d mpath=%d "
"vpm=%02x\n", id->ssid, id->devno, rc, pgroup, mpath,
sch->vpm);
ccw_device_verify_done(cdev, rc);
}
/*
* Create channel program to perform a NOOP.
*/
static void nop_build_cp(struct ccw_device *cdev)
{
struct ccw_request *req = &cdev->private->req;
struct ccw1 *cp = cdev->private->dma_area->iccws;
cp->cmd_code = CCW_CMD_NOOP;
cp->cda = 0;
cp->count = 0;
cp->flags = CCW_FLAG_SLI;
req->cp = cp;
}
/*
* Perform NOOP on a single path.
*/
static void nop_do(struct ccw_device *cdev)
{
struct subchannel *sch = to_subchannel(cdev->dev.parent);
struct ccw_request *req = &cdev->private->req;
req->lpm = lpm_adjust(req->lpm, sch->schib.pmcw.pam & sch->opm &
~cdev->private->path_noirq_mask);
if (!req->lpm)
goto out_nopath;
nop_build_cp(cdev);
ccw_request_start(cdev);
return;
out_nopath:
verify_done(cdev, sch->vpm ? 0 : -EACCES);
}
/*
* Adjust NOOP I/O status.
*/
static enum io_status nop_filter(struct ccw_device *cdev, void *data,
struct irb *irb, enum io_status status)
{
/* Only subchannel status might indicate a path error. */
if (status == IO_STATUS_ERROR && irb->scsw.cmd.cstat == 0)
return IO_DONE;
return status;
}
/*
* Process NOOP request result for a single path.
*/
static void nop_callback(struct ccw_device *cdev, void *data, int rc)
{
struct subchannel *sch = to_subchannel(cdev->dev.parent);
struct ccw_request *req = &cdev->private->req;
switch (rc) {
case 0:
sch->vpm |= req->lpm;
break;
case -ETIME:
cdev->private->path_noirq_mask |= req->lpm;
break;
case -EACCES:
cdev->private->path_notoper_mask |= req->lpm;
break;
default:
goto err;
}
/* Continue on the next path. */
req->lpm >>= 1;
nop_do(cdev);
return;
err:
verify_done(cdev, rc);
}
/*
* Create channel program to perform SET PGID on a single path.
*/
static void spid_build_cp(struct ccw_device *cdev, u8 fn)
{
struct ccw_request *req = &cdev->private->req;
struct ccw1 *cp = cdev->private->dma_area->iccws;
int i = pathmask_to_pos(req->lpm);
struct pgid *pgid = &cdev->private->dma_area->pgid[i];
pgid->inf.fc = fn;
cp->cmd_code = CCW_CMD_SET_PGID;
cp->cda = virt_to_dma32(pgid);
cp->count = sizeof(*pgid);
cp->flags = CCW_FLAG_SLI;
req->cp = cp;
}
static void pgid_wipeout_callback(struct ccw_device *cdev, void *data, int rc)
{
if (rc) {
/* We don't know the path groups' state. Abort. */
verify_done(cdev, rc);
return;
}
/*
* Path groups have been reset. Restart path verification but
* leave paths in path_noirq_mask out.
*/
cdev->private->flags.pgid_unknown = 0;
verify_start(cdev);
}
/*
* Reset pathgroups and restart path verification, leave unusable paths out.
*/
static void pgid_wipeout_start(struct ccw_device *cdev)
{
struct subchannel *sch = to_subchannel(cdev->dev.parent);
struct ccw_dev_id *id = &cdev->private->dev_id;
struct ccw_request *req = &cdev->private->req;
u8 fn;
CIO_MSG_EVENT(2, "wipe: device 0.%x.%04x: pvm=%02x nim=%02x\n",
id->ssid, id->devno, cdev->private->pgid_valid_mask,
cdev->private->path_noirq_mask);
/* Initialize request data. */
memset(req, 0, sizeof(*req));
req->timeout = PGID_TIMEOUT;
req->maxretries = PGID_RETRIES;
req->lpm = sch->schib.pmcw.pam;
req->callback = pgid_wipeout_callback;
fn = SPID_FUNC_DISBAND;
if (cdev->private->flags.mpath)
fn |= SPID_FUNC_MULTI_PATH;
spid_build_cp(cdev, fn);
ccw_request_start(cdev);
}
/*
* Perform establish/resign SET PGID on a single path.
*/
static void spid_do(struct ccw_device *cdev)
{
struct subchannel *sch = to_subchannel(cdev->dev.parent);
struct ccw_request *req = &cdev->private->req;
u8 fn;
/* Use next available path that is not already in correct state. */
req->lpm = lpm_adjust(req->lpm, cdev->private->pgid_todo_mask);
if (!req->lpm)
goto out_nopath;
/* Channel program setup. */
if (req->lpm & sch->opm)
fn = SPID_FUNC_ESTABLISH;
else
fn = SPID_FUNC_RESIGN;
if (cdev->private->flags.mpath)
fn |= SPID_FUNC_MULTI_PATH;
spid_build_cp(cdev, fn);
ccw_request_start(cdev);
return;
out_nopath:
if (cdev->private->flags.pgid_unknown) {
/* At least one SPID could be partially done. */
pgid_wipeout_start(cdev);
return;
}
verify_done(cdev, sch->vpm ? 0 : -EACCES);
}
/*
* Process SET PGID request result for a single path.
*/
static void spid_callback(struct ccw_device *cdev, void *data, int rc)
{
struct subchannel *sch = to_subchannel(cdev->dev.parent);
struct ccw_request *req = &cdev->private->req;
switch (rc) {
case 0:
sch->vpm |= req->lpm & sch->opm;
break;
case -ETIME:
cdev->private->flags.pgid_unknown = 1;
cdev->private->path_noirq_mask |= req->lpm;
break;
case -EACCES:
cdev->private->path_notoper_mask |= req->lpm;
break;
case -EOPNOTSUPP:
if (cdev->private->flags.mpath) {
/* Try without multipathing. */
cdev->private->flags.mpath = 0;
goto out_restart;
}
/* Try without pathgrouping. */
cdev->private->flags.pgroup = 0;
goto out_restart;
default:
goto err;
}
req->lpm >>= 1;
spid_do(cdev);
return;
out_restart:
verify_start(cdev);
return;
err:
verify_done(cdev, rc);
}
static void spid_start(struct ccw_device *cdev)
{
struct ccw_request *req = &cdev->private->req;
/* Initialize request data. */
memset(req, 0, sizeof(*req));
req->timeout = PGID_TIMEOUT;
req->maxretries = PGID_RETRIES;
req->lpm = 0x80;
req->singlepath = 1;
req->callback = spid_callback;
spid_do(cdev);
}
static int pgid_is_reset(struct pgid *p)
{
char *c;
for (c = (char *)p + 1; c < (char *)(p + 1); c++) {
if (*c != 0)
return 0;
}
return 1;
}
static int pgid_cmp(struct pgid *p1, struct pgid *p2)
{
return memcmp((char *) p1 + 1, (char *) p2 + 1,
sizeof(struct pgid) - 1);
}
/*
* Determine pathgroup state from PGID data.
*/
static void pgid_analyze(struct ccw_device *cdev, struct pgid **p,
int *mismatch, u8 *reserved, u8 *reset)
{
struct pgid *pgid = &cdev->private->dma_area->pgid[0];
struct pgid *first = NULL;
int lpm;
int i;
*mismatch = 0;
*reserved = 0;
*reset = 0;
for (i = 0, lpm = 0x80; i < 8; i++, pgid++, lpm >>= 1) {
if ((cdev->private->pgid_valid_mask & lpm) == 0)
continue;
if (pgid->inf.ps.state2 == SNID_STATE2_RESVD_ELSE)
*reserved |= lpm;
if (pgid_is_reset(pgid)) {
*reset |= lpm;
continue;
}
if (!first) {
first = pgid;
continue;
}
if (pgid_cmp(pgid, first) != 0)
*mismatch = 1;
}
if (!first)
first = &channel_subsystems[0]->global_pgid;
*p = first;
}
static u8 pgid_to_donepm(struct ccw_device *cdev)
{
struct subchannel *sch = to_subchannel(cdev->dev.parent);
struct pgid *pgid;
int i;
int lpm;
u8 donepm = 0;
/* Set bits for paths which are already in the target state. */
for (i = 0; i < 8; i++) {
lpm = 0x80 >> i;
if ((cdev->private->pgid_valid_mask & lpm) == 0)
continue;
pgid = &cdev->private->dma_area->pgid[i];
if (sch->opm & lpm) {
if (pgid->inf.ps.state1 != SNID_STATE1_GROUPED)
continue;
} else {
if (pgid->inf.ps.state1 != SNID_STATE1_UNGROUPED)
continue;
}
if (cdev->private->flags.mpath) {
if (pgid->inf.ps.state3 != SNID_STATE3_MULTI_PATH)
continue;
} else {
if (pgid->inf.ps.state3 != SNID_STATE3_SINGLE_PATH)
continue;
}
donepm |= lpm;
}
return donepm;
}
static void pgid_fill(struct ccw_device *cdev, struct pgid *pgid)
{
int i;
for (i = 0; i < 8; i++)
memcpy(&cdev->private->dma_area->pgid[i], pgid,
sizeof(struct pgid));
}
/*
* Process SENSE PGID data and report result.
*/
static void snid_done(struct ccw_device *cdev, int rc)
{
struct ccw_dev_id *id = &cdev->private->dev_id;
struct subchannel *sch = to_subchannel(cdev->dev.parent);
struct pgid *pgid;
int mismatch = 0;
u8 reserved = 0;
u8 reset = 0;
u8 donepm;
if (rc)
goto out;
pgid_analyze(cdev, &pgid, &mismatch, &reserved, &reset);
if (reserved == cdev->private->pgid_valid_mask)
rc = -EUSERS;
else if (mismatch)
rc = -EOPNOTSUPP;
else {
donepm = pgid_to_donepm(cdev);
sch->vpm = donepm & sch->opm;
cdev->private->pgid_reset_mask |= reset;
cdev->private->pgid_todo_mask &=
~(donepm | cdev->private->path_noirq_mask);
pgid_fill(cdev, pgid);
}
out:
CIO_MSG_EVENT(2, "snid: device 0.%x.%04x: rc=%d pvm=%02x vpm=%02x "
"todo=%02x mism=%d rsvd=%02x reset=%02x\n", id->ssid,
id->devno, rc, cdev->private->pgid_valid_mask, sch->vpm,
cdev->private->pgid_todo_mask, mismatch, reserved, reset);
switch (rc) {
case 0:
if (cdev->private->flags.pgid_unknown) {
pgid_wipeout_start(cdev);
return;
}
/* Anything left to do? */
if (cdev->private->pgid_todo_mask == 0) {
verify_done(cdev, sch->vpm == 0 ? -EACCES : 0);
return;
}
/* Perform path-grouping. */
spid_start(cdev);
break;
case -EOPNOTSUPP:
/* Path-grouping not supported. */
cdev->private->flags.pgroup = 0;
cdev->private->flags.mpath = 0;
verify_start(cdev);
break;
default:
verify_done(cdev, rc);
}
}
/*
* Create channel program to perform a SENSE PGID on a single path.
*/
static void snid_build_cp(struct ccw_device *cdev)
{
struct ccw_request *req = &cdev->private->req;
struct ccw1 *cp = cdev->private->dma_area->iccws;
int i = pathmask_to_pos(req->lpm);
/* Channel program setup. */
cp->cmd_code = CCW_CMD_SENSE_PGID;
cp->cda = virt_to_dma32(&cdev->private->dma_area->pgid[i]);
cp->count = sizeof(struct pgid);
cp->flags = CCW_FLAG_SLI;
req->cp = cp;
}
/*
* Perform SENSE PGID on a single path.
*/
static void snid_do(struct ccw_device *cdev)
{
struct subchannel *sch = to_subchannel(cdev->dev.parent);
struct ccw_request *req = &cdev->private->req;
int ret;
req->lpm = lpm_adjust(req->lpm, sch->schib.pmcw.pam &
~cdev->private->path_noirq_mask);
if (!req->lpm)
goto out_nopath;
snid_build_cp(cdev);
ccw_request_start(cdev);
return;
out_nopath:
if (cdev->private->pgid_valid_mask)
ret = 0;
else if (cdev->private->path_noirq_mask)
ret = -ETIME;
else
ret = -EACCES;
snid_done(cdev, ret);
}
/*
* Process SENSE PGID request result for single path.
*/
static void snid_callback(struct ccw_device *cdev, void *data, int rc)
{
struct ccw_request *req = &cdev->private->req;
switch (rc) {
case 0:
cdev->private->pgid_valid_mask |= req->lpm;
break;
case -ETIME:
cdev->private->flags.pgid_unknown = 1;
cdev->private->path_noirq_mask |= req->lpm;
break;
case -EACCES:
cdev->private->path_notoper_mask |= req->lpm;
break;
default:
goto err;
}
/* Continue on the next path. */
req->lpm >>= 1;
snid_do(cdev);
return;
err:
snid_done(cdev, rc);
}
/*
* Perform path verification.
*/
static void verify_start(struct ccw_device *cdev)
{
struct subchannel *sch = to_subchannel(cdev->dev.parent);
struct ccw_request *req = &cdev->private->req;
struct ccw_dev_id *devid = &cdev->private->dev_id;
sch->vpm = 0;
sch->lpm = sch->schib.pmcw.pam;
/* Initialize PGID data. */
memset(cdev->private->dma_area->pgid, 0,
sizeof(cdev->private->dma_area->pgid));
cdev->private->pgid_valid_mask = 0;
cdev->private->pgid_todo_mask = sch->schib.pmcw.pam;
cdev->private->path_notoper_mask = 0;
/* Initialize request data. */
memset(req, 0, sizeof(*req));
req->timeout = PGID_TIMEOUT;
req->maxretries = PGID_RETRIES;
req->lpm = 0x80;
req->singlepath = 1;
if (cdev->private->flags.pgroup) {
CIO_TRACE_EVENT(4, "snid");
CIO_HEX_EVENT(4, devid, sizeof(*devid));
req->callback = snid_callback;
snid_do(cdev);
} else {
CIO_TRACE_EVENT(4, "nop");
CIO_HEX_EVENT(4, devid, sizeof(*devid));
req->filter = nop_filter;
req->callback = nop_callback;
nop_do(cdev);
}
}
/**
* ccw_device_verify_start - perform path verification
* @cdev: ccw device
*
* Perform an I/O on each available channel path to @cdev to determine which
* paths are operational. The resulting path mask is stored in sch->vpm.
* If device options specify pathgrouping, establish a pathgroup for the
* operational paths. When finished, call ccw_device_verify_done with a
* return code specifying the result.
*/
void ccw_device_verify_start(struct ccw_device *cdev)
{
CIO_TRACE_EVENT(4, "vrfy");
CIO_HEX_EVENT(4, &cdev->private->dev_id, sizeof(cdev->private->dev_id));
/*
* Initialize pathgroup and multipath state with target values.
* They may change in the course of path verification.
*/
cdev->private->flags.pgroup = cdev->private->options.pgroup;
cdev->private->flags.mpath = cdev->private->options.mpath;
cdev->private->flags.doverify = 0;
cdev->private->path_noirq_mask = 0;
verify_start(cdev);
}
/*
* Process disband SET PGID request result.
*/
static void disband_callback(struct ccw_device *cdev, void *data, int rc)
{
struct subchannel *sch = to_subchannel(cdev->dev.parent);
struct ccw_dev_id *id = &cdev->private->dev_id;
if (rc)
goto out;
/* Ensure consistent multipathing state at device and channel. */
cdev->private->flags.mpath = 0;
if (sch->config.mp) {
sch->config.mp = 0;
rc = cio_commit_config(sch);
}
out:
CIO_MSG_EVENT(0, "disb: device 0.%x.%04x: rc=%d\n", id->ssid, id->devno,
rc);
ccw_device_disband_done(cdev, rc);
}
/**
* ccw_device_disband_start - disband pathgroup
* @cdev: ccw device
*
* Execute a SET PGID channel program on @cdev to disband a previously
* established pathgroup. When finished, call ccw_device_disband_done with
* a return code specifying the result.
*/
void ccw_device_disband_start(struct ccw_device *cdev)
{
struct subchannel *sch = to_subchannel(cdev->dev.parent);
struct ccw_request *req = &cdev->private->req;
u8 fn;
CIO_TRACE_EVENT(4, "disb");
CIO_HEX_EVENT(4, &cdev->private->dev_id, sizeof(cdev->private->dev_id));
/* Request setup. */
memset(req, 0, sizeof(*req));
req->timeout = PGID_TIMEOUT;
req->maxretries = PGID_RETRIES;
req->lpm = sch->schib.pmcw.pam & sch->opm;
req->singlepath = 1;
req->callback = disband_callback;
fn = SPID_FUNC_DISBAND;
if (cdev->private->flags.mpath)
fn |= SPID_FUNC_MULTI_PATH;
spid_build_cp(cdev, fn);
ccw_request_start(cdev);
}
struct stlck_data {
struct completion done;
int rc;
};
static void stlck_build_cp(struct ccw_device *cdev, void *buf1, void *buf2)
{
struct ccw_request *req = &cdev->private->req;
struct ccw1 *cp = cdev->private->dma_area->iccws;
cp[0].cmd_code = CCW_CMD_STLCK;
cp[0].cda = virt_to_dma32(buf1);
cp[0].count = 32;
cp[0].flags = CCW_FLAG_CC;
cp[1].cmd_code = CCW_CMD_RELEASE;
cp[1].cda = virt_to_dma32(buf2);
cp[1].count = 32;
cp[1].flags = 0;
req->cp = cp;
}
static void stlck_callback(struct ccw_device *cdev, void *data, int rc)
{
struct stlck_data *sdata = data;
sdata->rc = rc;
complete(&sdata->done);
}
/**
* ccw_device_stlck_start - perform unconditional release
* @cdev: ccw device
* @data: data pointer to be passed to ccw_device_stlck_done
* @buf1: data pointer used in channel program
* @buf2: data pointer used in channel program
*
* Execute a channel program on @cdev to release an existing PGID reservation.
*/
static void ccw_device_stlck_start(struct ccw_device *cdev, void *data,
void *buf1, void *buf2)
{
struct subchannel *sch = to_subchannel(cdev->dev.parent);
struct ccw_request *req = &cdev->private->req;
CIO_TRACE_EVENT(4, "stlck");
CIO_HEX_EVENT(4, &cdev->private->dev_id, sizeof(cdev->private->dev_id));
/* Request setup. */
memset(req, 0, sizeof(*req));
req->timeout = PGID_TIMEOUT;
req->maxretries = PGID_RETRIES;
req->lpm = sch->schib.pmcw.pam & sch->opm;
req->data = data;
req->callback = stlck_callback;
stlck_build_cp(cdev, buf1, buf2);
ccw_request_start(cdev);
}
/*
* Perform unconditional reserve + release.
*/
int ccw_device_stlck(struct ccw_device *cdev)
{
struct subchannel *sch = to_subchannel(cdev->dev.parent);
struct stlck_data data;
u8 *buffer;
int rc;
/* Check if steal lock operation is valid for this device. */
if (cdev->drv) {
if (!cdev->private->options.force)
return -EINVAL;
}
buffer = kzalloc(64, GFP_DMA | GFP_KERNEL);
if (!buffer)
return -ENOMEM;
init_completion(&data.done);
data.rc = -EIO;
spin_lock_irq(&sch->lock);
rc = cio_enable_subchannel(sch, (u32)virt_to_phys(sch));
if (rc)
goto out_unlock;
/* Perform operation. */
cdev->private->state = DEV_STATE_STEAL_LOCK;
ccw_device_stlck_start(cdev, &data, &buffer[0], &buffer[32]);
spin_unlock_irq(&sch->lock);
/* Wait for operation to finish. */
if (wait_for_completion_interruptible(&data.done)) {
/* Got a signal. */
spin_lock_irq(&sch->lock);
ccw_request_cancel(cdev);
spin_unlock_irq(&sch->lock);
wait_for_completion(&data.done);
}
rc = data.rc;
/* Check results. */
spin_lock_irq(&sch->lock);
cio_disable_subchannel(sch);
cdev->private->state = DEV_STATE_BOXED;
out_unlock:
spin_unlock_irq(&sch->lock);
kfree(buffer);
return rc;
}
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