forked from Minki/linux
aa343c695a
After a successful SRP login response we call scsi_unblock_requests() to kick any pending IOs. The callback to process this SRP response happens in a tasklet and therefore is in softirq context. The result of such is that when blk-mq is enabled, it is no longer safe to call scsi_unblock_requests() from this context. The result of duing so triggers the following WARN_ON splat in dmesg after a host reset or CRQ reenablement. WARNING: CPU: 0 PID: 0 at block/blk-mq.c:1375 __blk_mq_run_hw_queue+0x120/0x180 Modules linked in: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.0.0-rc8 #4 NIP [c0000000009771e0] __blk_mq_run_hw_queue+0x120/0x180 LR [c000000000977484] __blk_mq_delay_run_hw_queue+0x244/0x250 Call Trace: __blk_mq_delay_run_hw_queue+0x244/0x250 blk_mq_run_hw_queue+0x8c/0x1c0 blk_mq_run_hw_queues+0x60/0x90 scsi_run_queue+0x1e4/0x3b0 scsi_run_host_queues+0x48/0x80 login_rsp+0xb0/0x100 ibmvscsi_handle_crq+0x30c/0x3e0 ibmvscsi_task+0x54/0xe0 tasklet_action_common.isra.3+0xc4/0x1a0 __do_softirq+0x174/0x3f4 irq_exit+0xf0/0x120 __do_irq+0xb0/0x210 call_do_irq+0x14/0x24 do_IRQ+0x9c/0x130 hardware_interrupt_common+0x14c/0x150 This patch fixes the issue by introducing a new host action for unblocking the scsi requests in our seperate work thread. Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
119 lines
3.4 KiB
C
119 lines
3.4 KiB
C
/* ------------------------------------------------------------
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* ibmvscsi.h
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* (C) Copyright IBM Corporation 1994, 2003
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* Authors: Colin DeVilbiss (devilbis@us.ibm.com)
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* Santiago Leon (santil@us.ibm.com)
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* Dave Boutcher (sleddog@us.ibm.com)
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
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* USA
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*
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* ------------------------------------------------------------
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* Emulation of a SCSI host adapter for Virtual I/O devices
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*
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* This driver allows the Linux SCSI peripheral drivers to directly
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* access devices in the hosting partition, either on an iSeries
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* hypervisor system or a converged hypervisor system.
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*/
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#ifndef IBMVSCSI_H
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#define IBMVSCSI_H
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#include <linux/types.h>
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#include <linux/list.h>
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#include <linux/completion.h>
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#include <linux/interrupt.h>
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#include <scsi/viosrp.h>
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struct scsi_cmnd;
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struct Scsi_Host;
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/* Number of indirect bufs...the list of these has to fit in the
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* additional data of the srp_cmd struct along with the indirect
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* descriptor
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*/
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#define MAX_INDIRECT_BUFS 10
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#define IBMVSCSI_MAX_REQUESTS_DEFAULT 100
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#define IBMVSCSI_CMDS_PER_LUN_DEFAULT 16
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#define IBMVSCSI_MAX_SECTORS_DEFAULT 256 /* 32 * 8 = default max I/O 32 pages */
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#define IBMVSCSI_MAX_CMDS_PER_LUN 64
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#define IBMVSCSI_MAX_LUN 32
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/* ------------------------------------------------------------
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* Data Structures
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*/
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/* an RPA command/response transport queue */
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struct crq_queue {
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struct viosrp_crq *msgs;
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int size, cur;
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dma_addr_t msg_token;
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spinlock_t lock;
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};
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/* a unit of work for the hosting partition */
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struct srp_event_struct {
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union viosrp_iu *xfer_iu;
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struct scsi_cmnd *cmnd;
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struct list_head list;
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void (*done) (struct srp_event_struct *);
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struct viosrp_crq crq;
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struct ibmvscsi_host_data *hostdata;
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atomic_t free;
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union viosrp_iu iu;
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void (*cmnd_done) (struct scsi_cmnd *);
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struct completion comp;
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struct timer_list timer;
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union viosrp_iu *sync_srp;
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struct srp_direct_buf *ext_list;
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dma_addr_t ext_list_token;
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};
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/* a pool of event structs for use */
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struct event_pool {
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struct srp_event_struct *events;
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u32 size;
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int next;
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union viosrp_iu *iu_storage;
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dma_addr_t iu_token;
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};
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enum ibmvscsi_host_action {
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IBMVSCSI_HOST_ACTION_NONE = 0,
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IBMVSCSI_HOST_ACTION_RESET,
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IBMVSCSI_HOST_ACTION_REENABLE,
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IBMVSCSI_HOST_ACTION_UNBLOCK,
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};
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/* all driver data associated with a host adapter */
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struct ibmvscsi_host_data {
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struct list_head host_list;
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atomic_t request_limit;
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int client_migrated;
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enum ibmvscsi_host_action action;
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struct device *dev;
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struct event_pool pool;
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struct crq_queue queue;
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struct tasklet_struct srp_task;
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struct list_head sent;
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struct Scsi_Host *host;
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struct task_struct *work_thread;
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wait_queue_head_t work_wait_q;
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struct mad_adapter_info_data madapter_info;
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struct capabilities caps;
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dma_addr_t caps_addr;
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dma_addr_t adapter_info_addr;
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};
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#endif /* IBMVSCSI_H */
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