Initial import

1 files changed, 669 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..37ada05e8
--- /dev/null
+++ b/drivers/s390/cio/device_pgid.c
@@ -0,0 +1,669 @@
+/*
+ *  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);
+}
+