From: Eric Farman Date: Thu, 7 Jul 2022 15:57:35 +0200 Subject: vfio/ccw: Create a CLOSE FSM event Git-commit: f4b4ed44770221819daa19800f232a2708588c2f Patch-mainline: v6.0-rc1 References: bsc#1205701 Refactor the vfio_ccw_sch_quiesce() routine to extract the bit that disables the subchannel and affects the FSM state. Use this to form the basis of a CLOSE event that will mirror the OPEN event, and move the subchannel back to NOT_OPER state. A key difference with that mirroring is that while OPEN handles the transition from NOT_OPER => STANDBY, the later probing of the mdev handles the transition from STANDBY => IDLE. On the other hand, the CLOSE event will move from one of the operating states {IDLE, CP_PROCESSING, CP_PENDING} => NOT_OPER. That is, there is no stop in a STANDBY state on the deconfigure path. Add a call to cp_free() in this event, such that it is captured for the various permutations of this event. In the unlikely event that cio_disable_subchannel() returns -EBUSY, the remaining logic of vfio_ccw_sch_quiesce() can still be used. Signed-off-by: Eric Farman Reviewed-by: Matthew Rosato Link: https://lore.kernel.org/r/20220707135737.720765-10-farman@linux.ibm.com Signed-off-by: Alex Williamson Acked-by: Joerg Roedel --- drivers/s390/cio/vfio_ccw_drv.c | 17 +++++------------ drivers/s390/cio/vfio_ccw_fsm.c | 26 ++++++++++++++++++++++++++ drivers/s390/cio/vfio_ccw_ops.c | 14 ++------------ drivers/s390/cio/vfio_ccw_private.h | 1 + 4 files changed, 34 insertions(+), 24 deletions(-) diff --git a/drivers/s390/cio/vfio_ccw_drv.c b/drivers/s390/cio/vfio_ccw_drv.c index 7d9189640da3..f98c9915e73d 100644 --- a/drivers/s390/cio/vfio_ccw_drv.c +++ b/drivers/s390/cio/vfio_ccw_drv.c @@ -41,13 +41,6 @@ int vfio_ccw_sch_quiesce(struct subchannel *sch) DECLARE_COMPLETION_ONSTACK(completion); int iretry, ret = 0; - spin_lock_irq(sch->lock); - if (!sch->schib.pmcw.ena) - goto out_unlock; - ret = cio_disable_subchannel(sch); - if (ret != -EBUSY) - goto out_unlock; - iretry = 255; do { @@ -74,9 +67,7 @@ int vfio_ccw_sch_quiesce(struct subchannel *sch) spin_lock_irq(sch->lock); ret = cio_disable_subchannel(sch); } while (ret == -EBUSY); -out_unlock: - private->state = VFIO_CCW_STATE_NOT_OPER; - spin_unlock_irq(sch->lock); + return ret; } @@ -256,7 +247,7 @@ static void vfio_ccw_sch_remove(struct subchannel *sch) { struct vfio_ccw_private *private = dev_get_drvdata(&sch->dev); - vfio_ccw_sch_quiesce(sch); + vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_CLOSE); mdev_unregister_device(&sch->dev); dev_set_drvdata(&sch->dev, NULL); @@ -270,7 +261,9 @@ static void vfio_ccw_sch_remove(struct subchannel *sch) static void vfio_ccw_sch_shutdown(struct subchannel *sch) { - vfio_ccw_sch_quiesce(sch); + struct vfio_ccw_private *private = dev_get_drvdata(&sch->dev); + + vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_CLOSE); } /** diff --git a/drivers/s390/cio/vfio_ccw_fsm.c b/drivers/s390/cio/vfio_ccw_fsm.c index 2811b2040490..89eb3feffa41 100644 --- a/drivers/s390/cio/vfio_ccw_fsm.c +++ b/drivers/s390/cio/vfio_ccw_fsm.c @@ -384,6 +384,27 @@ static void fsm_open(struct vfio_ccw_private *private, spin_unlock_irq(sch->lock); } +static void fsm_close(struct vfio_ccw_private *private, + enum vfio_ccw_event event) +{ + struct subchannel *sch = private->sch; + int ret; + + spin_lock_irq(sch->lock); + + if (!sch->schib.pmcw.ena) + goto out_unlock; + + ret = cio_disable_subchannel(sch); + if (ret == -EBUSY) + vfio_ccw_sch_quiesce(sch); + +out_unlock: + private->state = VFIO_CCW_STATE_NOT_OPER; + spin_unlock_irq(sch->lock); + cp_free(&private->cp); +} + /* * Device statemachine */ @@ -394,6 +415,7 @@ fsm_func_t *vfio_ccw_jumptable[NR_VFIO_CCW_STATES][NR_VFIO_CCW_EVENTS] = { [VFIO_CCW_EVENT_ASYNC_REQ] = fsm_async_error, [VFIO_CCW_EVENT_INTERRUPT] = fsm_disabled_irq, [VFIO_CCW_EVENT_OPEN] = fsm_open, + [VFIO_CCW_EVENT_CLOSE] = fsm_nop, }, [VFIO_CCW_STATE_STANDBY] = { [VFIO_CCW_EVENT_NOT_OPER] = fsm_notoper, @@ -401,6 +423,7 @@ fsm_func_t *vfio_ccw_jumptable[NR_VFIO_CCW_STATES][NR_VFIO_CCW_EVENTS] = { [VFIO_CCW_EVENT_ASYNC_REQ] = fsm_async_error, [VFIO_CCW_EVENT_INTERRUPT] = fsm_irq, [VFIO_CCW_EVENT_OPEN] = fsm_notoper, + [VFIO_CCW_EVENT_CLOSE] = fsm_close, }, [VFIO_CCW_STATE_IDLE] = { [VFIO_CCW_EVENT_NOT_OPER] = fsm_notoper, @@ -408,6 +431,7 @@ fsm_func_t *vfio_ccw_jumptable[NR_VFIO_CCW_STATES][NR_VFIO_CCW_EVENTS] = { [VFIO_CCW_EVENT_ASYNC_REQ] = fsm_async_request, [VFIO_CCW_EVENT_INTERRUPT] = fsm_irq, [VFIO_CCW_EVENT_OPEN] = fsm_notoper, + [VFIO_CCW_EVENT_CLOSE] = fsm_close, }, [VFIO_CCW_STATE_CP_PROCESSING] = { [VFIO_CCW_EVENT_NOT_OPER] = fsm_notoper, @@ -415,6 +439,7 @@ fsm_func_t *vfio_ccw_jumptable[NR_VFIO_CCW_STATES][NR_VFIO_CCW_EVENTS] = { [VFIO_CCW_EVENT_ASYNC_REQ] = fsm_async_retry, [VFIO_CCW_EVENT_INTERRUPT] = fsm_irq, [VFIO_CCW_EVENT_OPEN] = fsm_notoper, + [VFIO_CCW_EVENT_CLOSE] = fsm_close, }, [VFIO_CCW_STATE_CP_PENDING] = { [VFIO_CCW_EVENT_NOT_OPER] = fsm_notoper, @@ -422,5 +447,6 @@ fsm_func_t *vfio_ccw_jumptable[NR_VFIO_CCW_STATES][NR_VFIO_CCW_EVENTS] = { [VFIO_CCW_EVENT_ASYNC_REQ] = fsm_async_request, [VFIO_CCW_EVENT_INTERRUPT] = fsm_irq, [VFIO_CCW_EVENT_OPEN] = fsm_notoper, + [VFIO_CCW_EVENT_CLOSE] = fsm_close, }, }; diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c index a7ea9358e461..fc5b83187bd9 100644 --- a/drivers/s390/cio/vfio_ccw_ops.c +++ b/drivers/s390/cio/vfio_ccw_ops.c @@ -33,9 +33,7 @@ static int vfio_ccw_mdev_reset(struct vfio_ccw_private *private) * There are still a lot more instructions need to be handled. We * should come back here later. */ - ret = vfio_ccw_sch_quiesce(sch); - if (ret) - return ret; + vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_CLOSE); ret = cio_enable_subchannel(sch, (u32)(unsigned long)sch); if (!ret) @@ -64,7 +62,6 @@ static int vfio_ccw_mdev_notifier(struct notifier_block *nb, if (vfio_ccw_mdev_reset(private)) return NOTIFY_BAD; - cp_free(&private->cp); return NOTIFY_OK; } @@ -159,15 +156,9 @@ static void vfio_ccw_mdev_remove(struct mdev_device *mdev) vfio_unregister_group_dev(&private->vdev); - if ((private->state != VFIO_CCW_STATE_NOT_OPER) && - (private->state != VFIO_CCW_STATE_STANDBY)) { - if (!vfio_ccw_sch_quiesce(private->sch)) - private->state = VFIO_CCW_STATE_STANDBY; - /* The state will be NOT_OPER on error. */ - } + vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_CLOSE); vfio_uninit_group_dev(&private->vdev); - cp_free(&private->cp); atomic_inc(&private->avail); } @@ -217,7 +208,6 @@ static void vfio_ccw_mdev_close_device(struct vfio_device *vdev) /* The state will be NOT_OPER on error. */ } - cp_free(&private->cp); vfio_ccw_unregister_dev_regions(private); vfio_unregister_notifier(vdev, VFIO_IOMMU_NOTIFY, &private->nb); } diff --git a/drivers/s390/cio/vfio_ccw_private.h b/drivers/s390/cio/vfio_ccw_private.h index 93e136ba369b..abac532bf03e 100644 --- a/drivers/s390/cio/vfio_ccw_private.h +++ b/drivers/s390/cio/vfio_ccw_private.h @@ -143,6 +143,7 @@ enum vfio_ccw_event { VFIO_CCW_EVENT_INTERRUPT, VFIO_CCW_EVENT_ASYNC_REQ, VFIO_CCW_EVENT_OPEN, + VFIO_CCW_EVENT_CLOSE, /* last element! */ NR_VFIO_CCW_EVENTS };