From 6ac999efeeff98f203eda8cf46d5016e99f58b0c Mon Sep 17 00:00:00 2001 From: Jitendra Bhivare Date: Wed, 20 Jan 2016 14:10:45 +0530 Subject: [PATCH] be2iscsi: Fix soft lockup in mgmt_get_all_if_id path using bmbx We are taking mbox_lock spinlock which disables pre-emption before we poll for mbox completion. Waiting there with spinlock held in excess of 20s will cause soft lockup. Actual fix is to change mbox_lock to mutex. The changes are done in phases. This is the first part. 1. Changed mgmt_get_all_if_id to use MCC where after posting lock is released. 2. Changed be_mbox_db_ready_wait to busy wait for 12s max and removed wait_event_timeout. Added error handling code for IO reads. OPCODE_COMMON_QUERY_FIRMWARE_CONFIG mbox command takes 8s time when unreachable boot targets configured. Signed-off-by: Jitendra Bhivare Reviewed-by: Hannes Reinecke Signed-off-by: Martin K. Petersen --- drivers/scsi/be2iscsi/be_cmds.c | 60 ++++++++++++++++----------------- drivers/scsi/be2iscsi/be_mgmt.c | 32 ++++++++++++------ 2 files changed, 51 insertions(+), 41 deletions(-) diff --git a/drivers/scsi/be2iscsi/be_cmds.c b/drivers/scsi/be2iscsi/be_cmds.c index 2778089b01a5..cd50e3ce35a6 100644 --- a/drivers/scsi/be2iscsi/be_cmds.c +++ b/drivers/scsi/be2iscsi/be_cmds.c @@ -587,47 +587,42 @@ int be_mcc_notify_wait(struct beiscsi_hba *phba) **/ static int be_mbox_db_ready_wait(struct be_ctrl_info *ctrl) { -#define BEISCSI_MBX_RDY_BIT_TIMEOUT 4000 /* 4sec */ +#define BEISCSI_MBX_RDY_BIT_TIMEOUT 12000 /* 12sec */ void __iomem *db = ctrl->db + MPU_MAILBOX_DB_OFFSET; struct beiscsi_hba *phba = pci_get_drvdata(ctrl->pdev); unsigned long timeout; - bool read_flag = false; - int ret = 0, i; u32 ready; - DECLARE_WAIT_QUEUE_HEAD_ONSTACK(rdybit_check_q); - if (beiscsi_error(phba)) - return -EIO; + /* + * This BMBX busy wait path is used during init only. + * For the commands executed during init, 5s should suffice. + */ + timeout = jiffies + msecs_to_jiffies(BEISCSI_MBX_RDY_BIT_TIMEOUT); + do { + if (beiscsi_error(phba)) + return -EIO; - timeout = jiffies + (HZ * 110); + ready = ioread32(db); + if (ready == 0xffffffff) + return -EIO; - do { - for (i = 0; i < BEISCSI_MBX_RDY_BIT_TIMEOUT; i++) { - ready = ioread32(db) & MPU_MAILBOX_DB_RDY_MASK; - if (ready) { - read_flag = true; - break; - } - mdelay(1); - } + ready &= MPU_MAILBOX_DB_RDY_MASK; + if (ready) + return 0; - if (!read_flag) { - wait_event_timeout(rdybit_check_q, - (read_flag != true), - HZ * 5); - } - } while ((time_before(jiffies, timeout)) && !read_flag); + if (time_after(jiffies, timeout)) + break; + mdelay(1); + } while (!ready); - if (!read_flag) { - beiscsi_log(phba, KERN_ERR, - BEISCSI_LOG_CONFIG | BEISCSI_LOG_MBOX, - "BC_%d : FW Timed Out\n"); - phba->fw_timeout = true; - beiscsi_ue_detect(phba); - ret = -EBUSY; - } + beiscsi_log(phba, KERN_ERR, + BEISCSI_LOG_CONFIG | BEISCSI_LOG_MBOX, + "BC_%d : FW Timed Out\n"); - return ret; + phba->fw_timeout = true; + beiscsi_ue_detect(phba); + + return -EBUSY; } /* @@ -674,6 +669,9 @@ int be_mbox_notify(struct be_ctrl_info *ctrl) if (status) return status; + /* RDY is set; small delay before CQE read. */ + udelay(1); + if (be_mcc_compl_is_new(compl)) { status = be_mcc_compl_process(ctrl, &mbox->compl); be_mcc_compl_use(compl); diff --git a/drivers/scsi/be2iscsi/be_mgmt.c b/drivers/scsi/be2iscsi/be_mgmt.c index aea3e6b9477d..7b54b23e756e 100644 --- a/drivers/scsi/be2iscsi/be_mgmt.c +++ b/drivers/scsi/be2iscsi/be_mgmt.c @@ -809,27 +809,39 @@ int mgmt_open_connection(struct beiscsi_hba *phba, unsigned int mgmt_get_all_if_id(struct beiscsi_hba *phba) { struct be_ctrl_info *ctrl = &phba->ctrl; - struct be_mcc_wrb *wrb = wrb_from_mbox(&ctrl->mbox_mem); - struct be_cmd_get_all_if_id_req *req = embedded_payload(wrb); - struct be_cmd_get_all_if_id_req *pbe_allid = req; + struct be_mcc_wrb *wrb; + struct be_cmd_get_all_if_id_req *req; + struct be_cmd_get_all_if_id_req *pbe_allid; + unsigned int tag; int status = 0; - memset(wrb, 0, sizeof(*wrb)); - spin_lock(&ctrl->mbox_lock); + tag = alloc_mcc_tag(phba); + if (!tag) { + spin_unlock(&ctrl->mbox_lock); + return -ENOMEM; + } + + wrb = wrb_from_mccq(phba); + req = embedded_payload(wrb); + wrb->tag0 |= tag; be_wrb_hdr_prepare(wrb, sizeof(*req), true, 0); be_cmd_hdr_prepare(&req->hdr, CMD_SUBSYSTEM_ISCSI, OPCODE_COMMON_ISCSI_NTWK_GET_ALL_IF_ID, sizeof(*req)); - status = be_mbox_notify(ctrl); - if (!status) - phba->interface_handle = pbe_allid->if_hndl_list[0]; - else { + be_mcc_notify(phba); + spin_unlock(&ctrl->mbox_lock); + + status = beiscsi_mccq_compl(phba, tag, &wrb, NULL); + if (status) { beiscsi_log(phba, KERN_WARNING, BEISCSI_LOG_CONFIG, "BG_%d : Failed in mgmt_get_all_if_id\n"); + return -EBUSY; } - spin_unlock(&ctrl->mbox_lock); + + pbe_allid = embedded_payload(wrb); + phba->interface_handle = pbe_allid->if_hndl_list[0]; return status; } -- 2.30.2