From 0f33ece5bc3d5a9567b65cfbc736e8f206ecfc7b Mon Sep 17 00:00:00 2001 From: Brian King Date: Thu, 17 Jun 2010 13:56:00 -0500 Subject: [SCSI] ibmvscsi: Fix softlockup on resume This fixes a softlockup seen on resume. During resume, the CRQ must be reenabled. However, the H_ENABLE_CRQ hcall used to do this may return H_BUSY or H_LONG_BUSY. When this happens, the caller is expected to retry later. This patch changes a simple loop, which was causing the softlockup, to a loop at task level which sleeps between retries rather than simply spinning. Signed-off-by: Brian King Signed-off-by: James Bottomley --- drivers/scsi/ibmvscsi/ibmvscsi.c | 117 +++++++++++++++++++++++++++++---------- 1 file changed, 89 insertions(+), 28 deletions(-) (limited to 'drivers/scsi/ibmvscsi/ibmvscsi.c') diff --git a/drivers/scsi/ibmvscsi/ibmvscsi.c b/drivers/scsi/ibmvscsi/ibmvscsi.c index aad35cc41e49..e50fad96329c 100644 --- a/drivers/scsi/ibmvscsi/ibmvscsi.c +++ b/drivers/scsi/ibmvscsi/ibmvscsi.c @@ -73,6 +73,7 @@ #include #include #include +#include #include #include #include @@ -504,14 +505,8 @@ static void ibmvscsi_reset_host(struct ibmvscsi_host_data *hostdata) atomic_set(&hostdata->request_limit, 0); purge_requests(hostdata, DID_ERROR); - if ((ibmvscsi_ops->reset_crq_queue(&hostdata->queue, hostdata)) || - (ibmvscsi_ops->send_crq(hostdata, 0xC001000000000000LL, 0)) || - (vio_enable_interrupts(to_vio_dev(hostdata->dev)))) { - atomic_set(&hostdata->request_limit, -1); - dev_err(hostdata->dev, "error after reset\n"); - } - - scsi_unblock_requests(hostdata->host); + hostdata->reset_crq = 1; + wake_up(&hostdata->work_wait_q); } /** @@ -1462,30 +1457,14 @@ void ibmvscsi_handle_crq(struct viosrp_crq *crq, /* We need to re-setup the interpartition connection */ dev_info(hostdata->dev, "Re-enabling adapter!\n"); hostdata->client_migrated = 1; + hostdata->reenable_crq = 1; purge_requests(hostdata, DID_REQUEUE); - if ((ibmvscsi_ops->reenable_crq_queue(&hostdata->queue, - hostdata)) || - (ibmvscsi_ops->send_crq(hostdata, - 0xC001000000000000LL, 0))) { - atomic_set(&hostdata->request_limit, - -1); - dev_err(hostdata->dev, "error after enable\n"); - } + wake_up(&hostdata->work_wait_q); } else { dev_err(hostdata->dev, "Virtual adapter failed rc %d!\n", crq->format); - - purge_requests(hostdata, DID_ERROR); - if ((ibmvscsi_ops->reset_crq_queue(&hostdata->queue, - hostdata)) || - (ibmvscsi_ops->send_crq(hostdata, - 0xC001000000000000LL, 0))) { - atomic_set(&hostdata->request_limit, - -1); - dev_err(hostdata->dev, "error after reset\n"); - } + ibmvscsi_reset_host(hostdata); } - scsi_unblock_requests(hostdata->host); return; case 0x80: /* real payload */ break; @@ -1850,6 +1829,75 @@ static unsigned long ibmvscsi_get_desired_dma(struct vio_dev *vdev) return desired_io; } +static void ibmvscsi_do_work(struct ibmvscsi_host_data *hostdata) +{ + int rc; + char *action = "reset"; + + if (hostdata->reset_crq) { + smp_rmb(); + hostdata->reset_crq = 0; + + rc = ibmvscsi_ops->reset_crq_queue(&hostdata->queue, hostdata); + if (!rc) + rc = ibmvscsi_ops->send_crq(hostdata, 0xC001000000000000LL, 0); + if (!rc) + rc = vio_enable_interrupts(to_vio_dev(hostdata->dev)); + } else if (hostdata->reenable_crq) { + smp_rmb(); + action = "enable"; + rc = ibmvscsi_ops->reenable_crq_queue(&hostdata->queue, hostdata); + hostdata->reenable_crq = 0; + if (!rc) + rc = ibmvscsi_ops->send_crq(hostdata, 0xC001000000000000LL, 0); + } else + return; + + if (rc) { + atomic_set(&hostdata->request_limit, -1); + dev_err(hostdata->dev, "error after %s\n", action); + } + + scsi_unblock_requests(hostdata->host); +} + +static int ibmvscsi_work_to_do(struct ibmvscsi_host_data *hostdata) +{ + if (kthread_should_stop()) + return 1; + else if (hostdata->reset_crq) { + smp_rmb(); + return 1; + } else if (hostdata->reenable_crq) { + smp_rmb(); + return 1; + } + + return 0; +} + +static int ibmvscsi_work(void *data) +{ + struct ibmvscsi_host_data *hostdata = data; + int rc; + + set_user_nice(current, -20); + + while (1) { + rc = wait_event_interruptible(hostdata->work_wait_q, + ibmvscsi_work_to_do(hostdata)); + + BUG_ON(rc); + + if (kthread_should_stop()) + break; + + ibmvscsi_do_work(hostdata); + } + + return 0; +} + /** * Called by bus code for each adapter */ @@ -1875,6 +1923,7 @@ static int ibmvscsi_probe(struct vio_dev *vdev, const struct vio_device_id *id) hostdata = shost_priv(host); memset(hostdata, 0x00, sizeof(*hostdata)); INIT_LIST_HEAD(&hostdata->sent); + init_waitqueue_head(&hostdata->work_wait_q); hostdata->host = host; hostdata->dev = dev; atomic_set(&hostdata->request_limit, -1); @@ -1885,10 +1934,19 @@ static int ibmvscsi_probe(struct vio_dev *vdev, const struct vio_device_id *id) goto persist_bufs_failed; } + hostdata->work_thread = kthread_run(ibmvscsi_work, hostdata, "%s_%d", + "ibmvscsi", host->host_no); + + if (IS_ERR(hostdata->work_thread)) { + dev_err(&vdev->dev, "couldn't initialize kthread. rc=%ld\n", + PTR_ERR(hostdata->work_thread)); + goto init_crq_failed; + } + rc = ibmvscsi_ops->init_crq_queue(&hostdata->queue, hostdata, max_events); if (rc != 0 && rc != H_RESOURCE) { dev_err(&vdev->dev, "couldn't initialize crq. rc=%d\n", rc); - goto init_crq_failed; + goto kill_kthread; } if (initialize_event_pool(&hostdata->pool, max_events, hostdata) != 0) { dev_err(&vdev->dev, "couldn't initialize event pool\n"); @@ -1944,6 +2002,8 @@ static int ibmvscsi_probe(struct vio_dev *vdev, const struct vio_device_id *id) release_event_pool(&hostdata->pool, hostdata); init_pool_failed: ibmvscsi_ops->release_crq_queue(&hostdata->queue, hostdata, max_events); + kill_kthread: + kthread_stop(hostdata->work_thread); init_crq_failed: unmap_persist_bufs(hostdata); persist_bufs_failed: @@ -1960,6 +2020,7 @@ static int ibmvscsi_remove(struct vio_dev *vdev) ibmvscsi_ops->release_crq_queue(&hostdata->queue, hostdata, max_events); + kthread_stop(hostdata->work_thread); srp_remove_host(hostdata->host); scsi_remove_host(hostdata->host); scsi_host_put(hostdata->host); -- cgit v1.2.3