--- /dev/null
+/*
+ * 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/types.h>
+#include <linux/errno.h>
+#include <linux/bitops.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 = 8 - ffs(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 = 8 - ffs(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);
+}
+
+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)
+{
+ ccw_device_stlck_done(cdev, data, rc);
+}
+
+/**
+ * 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.
+ * When finished, call ccw_device_stlck_done with a return code specifying the
+ * result.
+ */
+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);
+}
+
Code Review / kvmfornfv.git / blobdiff