91c36919a4
Calling a ccw driver's notify function without the ccw device lock held opens up a race window between discovery and handling of a change in the device operational state. As a result, the device driver may encounter unexpected device malfunction, leading to out-of-retry situations or similar. Remove race by extending the ccw device lock from state change discovery to the calling of the notify function. Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
135 lines
3.9 KiB
C
135 lines
3.9 KiB
C
#ifndef S390_DEVICE_H
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#define S390_DEVICE_H
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#include <asm/ccwdev.h>
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#include <asm/atomic.h>
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#include <linux/wait.h>
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#include "io_sch.h"
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/*
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* states of the device statemachine
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*/
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enum dev_state {
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DEV_STATE_NOT_OPER,
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DEV_STATE_SENSE_PGID,
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DEV_STATE_SENSE_ID,
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DEV_STATE_OFFLINE,
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DEV_STATE_VERIFY,
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DEV_STATE_ONLINE,
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DEV_STATE_W4SENSE,
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DEV_STATE_DISBAND_PGID,
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DEV_STATE_BOXED,
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/* states to wait for i/o completion before doing something */
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DEV_STATE_CLEAR_VERIFY,
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DEV_STATE_TIMEOUT_KILL,
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DEV_STATE_QUIESCE,
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/* special states for devices gone not operational */
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DEV_STATE_DISCONNECTED,
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DEV_STATE_DISCONNECTED_SENSE_ID,
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DEV_STATE_CMFCHANGE,
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DEV_STATE_CMFUPDATE,
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/* last element! */
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NR_DEV_STATES
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};
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/*
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* asynchronous events of the device statemachine
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*/
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enum dev_event {
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DEV_EVENT_NOTOPER,
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DEV_EVENT_INTERRUPT,
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DEV_EVENT_TIMEOUT,
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DEV_EVENT_VERIFY,
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/* last element! */
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NR_DEV_EVENTS
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};
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struct ccw_device;
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/*
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* action called through jumptable
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*/
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typedef void (fsm_func_t)(struct ccw_device *, enum dev_event);
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extern fsm_func_t *dev_jumptable[NR_DEV_STATES][NR_DEV_EVENTS];
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static inline void
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dev_fsm_event(struct ccw_device *cdev, enum dev_event dev_event)
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{
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dev_jumptable[cdev->private->state][dev_event](cdev, dev_event);
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}
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/*
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* Delivers 1 if the device state is final.
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*/
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static inline int
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dev_fsm_final_state(struct ccw_device *cdev)
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{
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return (cdev->private->state == DEV_STATE_NOT_OPER ||
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cdev->private->state == DEV_STATE_OFFLINE ||
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cdev->private->state == DEV_STATE_ONLINE ||
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cdev->private->state == DEV_STATE_BOXED);
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}
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extern struct workqueue_struct *ccw_device_work;
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extern wait_queue_head_t ccw_device_init_wq;
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extern atomic_t ccw_device_init_count;
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void io_subchannel_recog_done(struct ccw_device *cdev);
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int ccw_device_cancel_halt_clear(struct ccw_device *);
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void ccw_device_do_unreg_rereg(struct work_struct *);
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void ccw_device_move_to_orphanage(struct work_struct *);
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int ccw_device_is_orphan(struct ccw_device *);
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int ccw_device_recognition(struct ccw_device *);
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int ccw_device_online(struct ccw_device *);
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int ccw_device_offline(struct ccw_device *);
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/* Function prototypes for device status and basic sense stuff. */
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void ccw_device_accumulate_irb(struct ccw_device *, struct irb *);
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void ccw_device_accumulate_basic_sense(struct ccw_device *, struct irb *);
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int ccw_device_accumulate_and_sense(struct ccw_device *, struct irb *);
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int ccw_device_do_sense(struct ccw_device *, struct irb *);
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/* Function prototypes for sense id stuff. */
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void ccw_device_sense_id_start(struct ccw_device *);
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void ccw_device_sense_id_irq(struct ccw_device *, enum dev_event);
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void ccw_device_sense_id_done(struct ccw_device *, int);
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/* Function prototypes for path grouping stuff. */
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void ccw_device_sense_pgid_start(struct ccw_device *);
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void ccw_device_sense_pgid_irq(struct ccw_device *, enum dev_event);
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void ccw_device_sense_pgid_done(struct ccw_device *, int);
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void ccw_device_verify_start(struct ccw_device *);
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void ccw_device_verify_irq(struct ccw_device *, enum dev_event);
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void ccw_device_verify_done(struct ccw_device *, int);
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void ccw_device_disband_start(struct ccw_device *);
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void ccw_device_disband_irq(struct ccw_device *, enum dev_event);
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void ccw_device_disband_done(struct ccw_device *, int);
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int ccw_device_call_handler(struct ccw_device *);
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int ccw_device_stlck(struct ccw_device *);
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/* Helper function for machine check handling. */
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void ccw_device_trigger_reprobe(struct ccw_device *);
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void ccw_device_kill_io(struct ccw_device *);
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int ccw_device_notify(struct ccw_device *, int);
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void ccw_device_set_notoper(struct ccw_device *cdev);
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/* qdio needs this. */
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void ccw_device_set_timeout(struct ccw_device *, int);
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extern struct subchannel_id ccw_device_get_subchannel_id(struct ccw_device *);
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extern struct bus_type ccw_bus_type;
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/* Channel measurement facility related */
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void retry_set_schib(struct ccw_device *cdev);
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void cmf_retry_copy_block(struct ccw_device *);
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int cmf_reenable(struct ccw_device *);
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extern struct device_attribute dev_attr_cmb_enable;
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#endif
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