Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756547AbZKMPKu (ORCPT ); Fri, 13 Nov 2009 10:10:50 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756285AbZKMPKp (ORCPT ); Fri, 13 Nov 2009 10:10:45 -0500 Received: from mtagate7.de.ibm.com ([195.212.17.167]:41612 "EHLO mtagate7.de.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756191AbZKMPJJ (ORCPT ); Fri, 13 Nov 2009 10:09:09 -0500 Message-Id: <20091113150916.986219548@de.ibm.com> User-Agent: quilt/0.48-1 Date: Fri, 13 Nov 2009 16:09:07 +0100 From: Martin Schwidefsky To: linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org Cc: Heiko Carstens , Peter Oberparleiter , Martin Schwidefsky Subject: [patch 43/52] [PATCH] cio: make steal lock procedure more robust References: <20091113150824.351347652@de.ibm.com> Content-Disposition: inline; filename=142-cio-steal-lock.diff Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 10199 Lines: 331 From: Peter Oberparleiter An Unconditional Reserve + Release operation (steal lock) for a boxed device may fail when encountering special error cases (e.g. unit checks or path errors). Fix this by using the more robust ccw_request infrastructure for performing the steal lock CCW program. Signed-off-by: Peter Oberparleiter Signed-off-by: Martin Schwidefsky --- drivers/s390/cio/device.h | 4 + drivers/s390/cio/device_fsm.c | 55 +++++++++----------- drivers/s390/cio/device_ops.c | 112 +++++++++++++++++++---------------------- drivers/s390/cio/device_pgid.c | 52 +++++++++++++++++++ 4 files changed, 134 insertions(+), 89 deletions(-) Index: quilt-2.6/drivers/s390/cio/device_fsm.c =================================================================== --- quilt-2.6.orig/drivers/s390/cio/device_fsm.c 2009-11-13 16:08:21.000000000 +0100 +++ quilt-2.6/drivers/s390/cio/device_fsm.c 2009-11-13 16:08:21.000000000 +0100 @@ -641,6 +641,23 @@ } /* + * Handle path verification event in boxed state. + */ +static void ccw_device_boxed_verify(struct ccw_device *cdev, + enum dev_event dev_event) +{ + struct subchannel *sch = to_subchannel(cdev->dev.parent); + + if (cdev->online) { + if (cio_enable_subchannel(sch, (u32) (addr_t) sch)) + ccw_device_done(cdev, DEV_STATE_NOT_OPER); + else + ccw_device_online_verify(cdev, dev_event); + } else + css_schedule_eval(sch->schid); +} + +/* * Got an interrupt for a normal io (state online). */ static void @@ -817,32 +834,6 @@ } static void -ccw_device_stlck_done(struct ccw_device *cdev, enum dev_event dev_event) -{ - struct irb *irb; - - switch (dev_event) { - case DEV_EVENT_INTERRUPT: - irb = (struct irb *) __LC_IRB; - /* Check for unsolicited interrupt. */ - if ((scsw_stctl(&irb->scsw) == - (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) && - (!scsw_cc(&irb->scsw))) - /* FIXME: we should restart stlck here, but this - * is extremely unlikely ... */ - goto out_wakeup; - - ccw_device_accumulate_irb(cdev, irb); - /* We don't care about basic sense etc. */ - break; - default: /* timeout */ - break; - } -out_wakeup: - wake_up(&cdev->private->wait_q); -} - -static void ccw_device_start_id(struct ccw_device *cdev, enum dev_event dev_event) { struct subchannel *sch; @@ -1010,9 +1001,9 @@ }, [DEV_STATE_BOXED] = { [DEV_EVENT_NOTOPER] = ccw_device_generic_notoper, - [DEV_EVENT_INTERRUPT] = ccw_device_stlck_done, - [DEV_EVENT_TIMEOUT] = ccw_device_stlck_done, - [DEV_EVENT_VERIFY] = ccw_device_nop, + [DEV_EVENT_INTERRUPT] = ccw_device_nop, + [DEV_EVENT_TIMEOUT] = ccw_device_nop, + [DEV_EVENT_VERIFY] = ccw_device_boxed_verify, }, /* states to wait for i/o completion before doing something */ [DEV_STATE_TIMEOUT_KILL] = { @@ -1052,6 +1043,12 @@ [DEV_EVENT_TIMEOUT] = ccw_device_update_cmfblock, [DEV_EVENT_VERIFY] = ccw_device_update_cmfblock, }, + [DEV_STATE_STEAL_LOCK] = { + [DEV_EVENT_NOTOPER] = ccw_device_request_event, + [DEV_EVENT_INTERRUPT] = ccw_device_request_event, + [DEV_EVENT_TIMEOUT] = ccw_device_request_event, + [DEV_EVENT_VERIFY] = ccw_device_nop, + }, }; EXPORT_SYMBOL_GPL(ccw_device_set_timeout); Index: quilt-2.6/drivers/s390/cio/device.h =================================================================== --- quilt-2.6.orig/drivers/s390/cio/device.h 2009-11-13 16:08:21.000000000 +0100 +++ quilt-2.6/drivers/s390/cio/device.h 2009-11-13 16:08:21.000000000 +0100 @@ -28,6 +28,7 @@ DEV_STATE_DISCONNECTED_SENSE_ID, DEV_STATE_CMFCHANGE, DEV_STATE_CMFUPDATE, + DEV_STATE_STEAL_LOCK, /* last element! */ NR_DEV_STATES }; @@ -116,6 +117,9 @@ void ccw_device_disband_start(struct ccw_device *); void ccw_device_disband_done(struct ccw_device *, int); +void ccw_device_stlck_start(struct ccw_device *, void *, void *, void *); +void ccw_device_stlck_done(struct ccw_device *, void *, int); + int ccw_device_call_handler(struct ccw_device *); int ccw_device_stlck(struct ccw_device *); Index: quilt-2.6/drivers/s390/cio/device_ops.c =================================================================== --- quilt-2.6.orig/drivers/s390/cio/device_ops.c 2009-11-13 16:08:21.000000000 +0100 +++ quilt-2.6/drivers/s390/cio/device_ops.c 2009-11-13 16:08:21.000000000 +0100 @@ -11,6 +11,7 @@ #include #include #include +#include #include #include @@ -504,74 +505,65 @@ return sch->lpm; } -/* - * Try to break the lock on a boxed device. - */ -int -ccw_device_stlck(struct ccw_device *cdev) -{ - void *buf, *buf2; - unsigned long flags; - struct subchannel *sch; - int ret; +struct stlck_data { + struct completion done; + int rc; +}; - if (!cdev) - return -ENODEV; +void ccw_device_stlck_done(struct ccw_device *cdev, void *data, int rc) +{ + struct stlck_data *sdata = data; - if (cdev->drv && !cdev->private->options.force) - return -EINVAL; + sdata->rc = rc; + complete(&sdata->done); +} - sch = to_subchannel(cdev->dev.parent); - - CIO_TRACE_EVENT(2, "stl lock"); - CIO_TRACE_EVENT(2, dev_name(&cdev->dev)); +/* + * 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; - buf = kmalloc(32*sizeof(char), GFP_DMA|GFP_KERNEL); - if (!buf) - return -ENOMEM; - buf2 = kmalloc(32*sizeof(char), GFP_DMA|GFP_KERNEL); - if (!buf2) { - kfree(buf); - return -ENOMEM; + /* Check if steal lock operation is valid for this device. */ + if (cdev->drv) { + if (!cdev->private->options.force) + return -EINVAL; } - spin_lock_irqsave(sch->lock, flags); - ret = cio_enable_subchannel(sch, (u32)(addr_t)sch); - if (ret) - goto out_unlock; - /* - * Setup ccw. We chain an unconditional reserve and a release so we - * only break the lock. - */ - cdev->private->iccws[0].cmd_code = CCW_CMD_STLCK; - cdev->private->iccws[0].cda = (__u32) __pa(buf); - cdev->private->iccws[0].count = 32; - cdev->private->iccws[0].flags = CCW_FLAG_CC; - cdev->private->iccws[1].cmd_code = CCW_CMD_RELEASE; - cdev->private->iccws[1].cda = (__u32) __pa(buf2); - cdev->private->iccws[1].count = 32; - cdev->private->iccws[1].flags = 0; - ret = cio_start(sch, cdev->private->iccws, 0); - if (ret) { - cio_disable_subchannel(sch); //FIXME: return code? + 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); } - cdev->private->irb.scsw.cmd.actl |= SCSW_ACTL_START_PEND; - spin_unlock_irqrestore(sch->lock, flags); - wait_event(cdev->private->wait_q, - cdev->private->irb.scsw.cmd.actl == 0); - spin_lock_irqsave(sch->lock, flags); - cio_disable_subchannel(sch); //FIXME: return code? - if ((cdev->private->irb.scsw.cmd.dstat != - (DEV_STAT_CHN_END|DEV_STAT_DEV_END)) || - (cdev->private->irb.scsw.cmd.cstat != 0)) - ret = -EIO; - /* Clear irb. */ - memset(&cdev->private->irb, 0, sizeof(struct irb)); + rc = data.rc; + /* Check results. */ + spin_lock_irq(sch->lock); + cio_disable_subchannel(sch); + cdev->private->state = DEV_STATE_BOXED; out_unlock: - kfree(buf); - kfree(buf2); - spin_unlock_irqrestore(sch->lock, flags); - return ret; + spin_unlock_irq(sch->lock); + kfree(buffer); + + return rc; } void *ccw_device_get_chp_desc(struct ccw_device *cdev, int chp_no) Index: quilt-2.6/drivers/s390/cio/device_pgid.c =================================================================== --- quilt-2.6.orig/drivers/s390/cio/device_pgid.c 2009-11-13 16:08:21.000000000 +0100 +++ quilt-2.6/drivers/s390/cio/device_pgid.c 2009-11-13 16:08:21.000000000 +0100 @@ -507,3 +507,55 @@ 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); +} + -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/