From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Williams Subject: [PATCH v2 22/28] libsas: add mutex for SMP task execution Date: Thu, 22 Dec 2011 19:00:23 -0800 Message-ID: <20111223030023.21827.20295.stgit@localhost6.localdomain6> References: <20111223025350.21827.85779.stgit@localhost6.localdomain6> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: Received: from mga09.intel.com ([134.134.136.24]:1732 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756274Ab1LWDAX (ORCPT ); Thu, 22 Dec 2011 22:00:23 -0500 In-Reply-To: <20111223025350.21827.85779.stgit@localhost6.localdomain6> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: linux-scsi@vger.kernel.org Cc: linux-ide@vger.kernel.org, Jeff Skirvin From: Jeff Skirvin SAS does not tag SMP requests, and at least one lldd (isci) does not permit more than one in-flight request at a time. Signed-off-by: Jeff Skirvin Signed-off-by: Dan Williams --- drivers/scsi/libsas/sas_discover.c | 1 + drivers/scsi/libsas/sas_expander.c | 29 ++++++++++++++++------------- include/scsi/libsas.h | 2 ++ 3 files changed, 19 insertions(+), 13 deletions(-) diff --git a/drivers/scsi/libsas/sas_discover.c b/drivers/scsi/libsas/sas_discover.c index 3905143..6e5fdfd 100644 --- a/drivers/scsi/libsas/sas_discover.c +++ b/drivers/scsi/libsas/sas_discover.c @@ -43,6 +43,7 @@ void sas_init_dev(struct domain_device *dev) case EDGE_DEV: case FANOUT_DEV: INIT_LIST_HEAD(&dev->ex_dev.children); + mutex_init(&dev->ex_dev.cmd_mutex); break; case SATA_DEV: case SATA_PM: diff --git a/drivers/scsi/libsas/sas_expander.c b/drivers/scsi/libsas/sas_expander.c index 9d2bb32..fd77ea3 100644 --- a/drivers/scsi/libsas/sas_expander.c +++ b/drivers/scsi/libsas/sas_expander.c @@ -72,11 +72,13 @@ static int smp_execute_task(struct domain_device *dev, void *req, int req_size, struct sas_internal *i = to_sas_internal(dev->port->ha->core.shost->transportt); + mutex_lock(&dev->ex_dev.cmd_mutex); for (retry = 0; retry < 3; retry++) { task = sas_alloc_task(GFP_KERNEL); - if (!task) - return -ENOMEM; - + if (!task) { + res = -ENOMEM; + break; + } task->dev = dev; task->task_proto = dev->tproto; sg_init_one(&task->smp_task.smp_req, req, req_size); @@ -94,7 +96,7 @@ static int smp_execute_task(struct domain_device *dev, void *req, int req_size, if (res) { del_timer(&task->timer); SAS_DPRINTK("executing SMP task failed:%d\n", res); - goto ex_err; + break; } wait_for_completion(&task->completion); @@ -104,21 +106,23 @@ static int smp_execute_task(struct domain_device *dev, void *req, int req_size, i->dft->lldd_abort_task(task); if (!(task->task_state_flags & SAS_TASK_STATE_DONE)) { SAS_DPRINTK("SMP task aborted and not done\n"); - goto ex_err; + break; } } if (task->task_status.resp == SAS_TASK_COMPLETE && task->task_status.stat == SAM_STAT_GOOD) { res = 0; break; - } if (task->task_status.resp == SAS_TASK_COMPLETE && - task->task_status.stat == SAS_DATA_UNDERRUN) { + } + if (task->task_status.resp == SAS_TASK_COMPLETE && + task->task_status.stat == SAS_DATA_UNDERRUN) { /* no error, but return the number of bytes of * underrun */ res = task->task_status.residual; break; - } if (task->task_status.resp == SAS_TASK_COMPLETE && - task->task_status.stat == SAS_DATA_OVERRUN) { + } + if (task->task_status.resp == SAS_TASK_COMPLETE && + task->task_status.stat == SAS_DATA_OVERRUN) { res = -EMSGSIZE; break; } else { @@ -131,11 +135,10 @@ static int smp_execute_task(struct domain_device *dev, void *req, int req_size, task = NULL; } } -ex_err: + mutex_unlock(&dev->ex_dev.cmd_mutex); + BUG_ON(retry == 3 && task != NULL); - if (task != NULL) { - sas_free_task(task); - } + sas_free_task(task); return res; } diff --git a/include/scsi/libsas.h b/include/scsi/libsas.h index 7ba7095..6e1c640 100644 --- a/include/scsi/libsas.h +++ b/include/scsi/libsas.h @@ -153,6 +153,8 @@ struct expander_device { struct ex_phy *ex_phy; struct sas_port *parent_port; + + struct mutex cmd_mutex; }; /* ---------- SATA device ---------- */