diff options
Diffstat (limited to 'drivers/s390/cio/device_pgid.c')
| -rw-r--r-- | drivers/s390/cio/device_pgid.c | 724 |
1 files changed, 724 insertions, 0 deletions
diff --git a/drivers/s390/cio/device_pgid.c b/drivers/s390/cio/device_pgid.c new file mode 100644 index 000000000..d30a3babf --- /dev/null +++ b/drivers/s390/cio/device_pgid.c @@ -0,0 +1,724 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * CCW device PGID and path verification I/O handling. + * + * Copyright IBM Corp. 2002, 2009 + * Author(s): Cornelia Huck <cornelia.huck@de.ibm.com> + * Martin Schwidefsky <schwidefsky@de.ibm.com> + * Peter Oberparleiter <peter.oberparleiter@de.ibm.com> + */ + +#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 <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->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->iccws; + int i = pathmask_to_pos(req->lpm); + struct pgid *pgid = &cdev->private->pgid[i]; + + pgid->inf.fc = fn; + cp->cmd_code = CCW_CMD_SET_PGID; + cp->cda = (u32) (addr_t) 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->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->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->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->iccws; + int i = pathmask_to_pos(req->lpm); + + /* Channel program setup. */ + cp->cmd_code = CCW_CMD_SENSE_PGID; + cp->cda = (u32) (addr_t) &cdev->private->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->pgid, 0, sizeof(cdev->private->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->iccws; + + cp[0].cmd_code = CCW_CMD_STLCK; + cp[0].cda = (u32) (addr_t) buf1; + cp[0].count = 32; + cp[0].flags = CCW_FLAG_CC; + cp[1].cmd_code = CCW_CMD_RELEASE; + cp[1].cda = (u32) (addr_t) 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) (addr_t) 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; +} |