| Message ID | 1524149293-12658-8-git-send-email-pmorel@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, 19 Apr 2018 16:48:10 +0200 Pierre Morel <pmorel@linux.vnet.ibm.com> wrote: > The VFIO_CCW_EVENT_INIT event allows to export the initial state > into the FSM. I don't know, that feels a bit unintuitive to me. I would naively expect initialization to be done _before_ we activate processing via the state machine. > > Signed-off-by: Pierre Morel <pmorel@linux.vnet.ibm.com> > --- > drivers/s390/cio/vfio_ccw_drv.c | 26 +++++++++++--------------- > drivers/s390/cio/vfio_ccw_fsm.c | 21 +++++++++++++++++++++ > drivers/s390/cio/vfio_ccw_ops.c | 11 ----------- > drivers/s390/cio/vfio_ccw_private.h | 1 + > 4 files changed, 33 insertions(+), 26 deletions(-) > /* > * Device statemachine > */ > fsm_func_t *vfio_ccw_jumptable[NR_VFIO_CCW_STATES][NR_VFIO_CCW_EVENTS] = { > [VFIO_CCW_STATE_NOT_OPER] = { > + [VFIO_CCW_EVENT_INIT] = fsm_init, > [VFIO_CCW_EVENT_NOT_OPER] = fsm_nop, > [VFIO_CCW_EVENT_SSCH_REQ] = fsm_io_error, > [VFIO_CCW_EVENT_INTERRUPT] = fsm_disabled_irq, > [VFIO_CCW_EVENT_SCH_EVENT] = fsm_nop, > }, > [VFIO_CCW_STATE_STANDBY] = { > + [VFIO_CCW_EVENT_INIT] = fsm_nop, > [VFIO_CCW_EVENT_NOT_OPER] = fsm_notoper, > [VFIO_CCW_EVENT_SSCH_REQ] = fsm_io_error, > [VFIO_CCW_EVENT_INTERRUPT] = fsm_irq, > [VFIO_CCW_EVENT_SCH_EVENT] = fsm_sch_event, > }, > [VFIO_CCW_STATE_IDLE] = { > + [VFIO_CCW_EVENT_INIT] = fsm_nop, > [VFIO_CCW_EVENT_NOT_OPER] = fsm_notoper, > [VFIO_CCW_EVENT_SSCH_REQ] = fsm_io_request, > [VFIO_CCW_EVENT_INTERRUPT] = fsm_irq, > [VFIO_CCW_EVENT_SCH_EVENT] = fsm_sch_event, > }, > [VFIO_CCW_STATE_BOXED] = { > + [VFIO_CCW_EVENT_INIT] = fsm_nop, > [VFIO_CCW_EVENT_NOT_OPER] = fsm_notoper, > [VFIO_CCW_EVENT_SSCH_REQ] = fsm_io_busy, > [VFIO_CCW_EVENT_INTERRUPT] = fsm_irq, > [VFIO_CCW_EVENT_SCH_EVENT] = fsm_sch_event, > }, > [VFIO_CCW_STATE_BUSY] = { > + [VFIO_CCW_EVENT_INIT] = fsm_nop, > [VFIO_CCW_EVENT_NOT_OPER] = fsm_notoper, > [VFIO_CCW_EVENT_SSCH_REQ] = fsm_io_busy, > [VFIO_CCW_EVENT_INTERRUPT] = fsm_irq, ...especially as you only call it if in the NOT_OPER state. Why should this event be generated in any case but in the very beginning?
On 30/04/2018 17:39, Cornelia Huck wrote: > On Thu, 19 Apr 2018 16:48:10 +0200 > Pierre Morel <pmorel@linux.vnet.ibm.com> wrote: > >> The VFIO_CCW_EVENT_INIT event allows to export the initial state >> into the FSM. > I don't know, that feels a bit unintuitive to me. I would naively > expect initialization to be done _before_ we activate processing via > the state machine. > >> Signed-off-by: Pierre Morel <pmorel@linux.vnet.ibm.com> >> --- >> drivers/s390/cio/vfio_ccw_drv.c | 26 +++++++++++--------------- >> drivers/s390/cio/vfio_ccw_fsm.c | 21 +++++++++++++++++++++ >> drivers/s390/cio/vfio_ccw_ops.c | 11 ----------- >> drivers/s390/cio/vfio_ccw_private.h | 1 + >> 4 files changed, 33 insertions(+), 26 deletions(-) >> /* >> * Device statemachine >> */ >> fsm_func_t *vfio_ccw_jumptable[NR_VFIO_CCW_STATES][NR_VFIO_CCW_EVENTS] = { >> [VFIO_CCW_STATE_NOT_OPER] = { >> + [VFIO_CCW_EVENT_INIT] = fsm_init, >> [VFIO_CCW_EVENT_NOT_OPER] = fsm_nop, >> [VFIO_CCW_EVENT_SSCH_REQ] = fsm_io_error, >> [VFIO_CCW_EVENT_INTERRUPT] = fsm_disabled_irq, >> [VFIO_CCW_EVENT_SCH_EVENT] = fsm_nop, >> }, >> [VFIO_CCW_STATE_STANDBY] = { >> + [VFIO_CCW_EVENT_INIT] = fsm_nop, >> [VFIO_CCW_EVENT_NOT_OPER] = fsm_notoper, >> [VFIO_CCW_EVENT_SSCH_REQ] = fsm_io_error, >> [VFIO_CCW_EVENT_INTERRUPT] = fsm_irq, >> [VFIO_CCW_EVENT_SCH_EVENT] = fsm_sch_event, >> }, >> [VFIO_CCW_STATE_IDLE] = { >> + [VFIO_CCW_EVENT_INIT] = fsm_nop, >> [VFIO_CCW_EVENT_NOT_OPER] = fsm_notoper, >> [VFIO_CCW_EVENT_SSCH_REQ] = fsm_io_request, >> [VFIO_CCW_EVENT_INTERRUPT] = fsm_irq, >> [VFIO_CCW_EVENT_SCH_EVENT] = fsm_sch_event, >> }, >> [VFIO_CCW_STATE_BOXED] = { >> + [VFIO_CCW_EVENT_INIT] = fsm_nop, >> [VFIO_CCW_EVENT_NOT_OPER] = fsm_notoper, >> [VFIO_CCW_EVENT_SSCH_REQ] = fsm_io_busy, >> [VFIO_CCW_EVENT_INTERRUPT] = fsm_irq, >> [VFIO_CCW_EVENT_SCH_EVENT] = fsm_sch_event, >> }, >> [VFIO_CCW_STATE_BUSY] = { >> + [VFIO_CCW_EVENT_INIT] = fsm_nop, >> [VFIO_CCW_EVENT_NOT_OPER] = fsm_notoper, >> [VFIO_CCW_EVENT_SSCH_REQ] = fsm_io_busy, >> [VFIO_CCW_EVENT_INTERRUPT] = fsm_irq, > ...especially as you only call it if in the NOT_OPER state. Why should > this event be generated in any case but in the very beginning? > It is the only way to go out of the NOT_OPER state. The idea is to introduce recoverycode in a later version. However, no problem to suppress this state until we get there so I will remove it in V2.
diff --git a/drivers/s390/cio/vfio_ccw_drv.c b/drivers/s390/cio/vfio_ccw_drv.c index 1c9422a..f6e7def1 100644 --- a/drivers/s390/cio/vfio_ccw_drv.c +++ b/drivers/s390/cio/vfio_ccw_drv.c @@ -116,31 +116,27 @@ static int vfio_ccw_sch_probe(struct subchannel *sch) private = kzalloc(sizeof(*private), GFP_KERNEL | GFP_DMA); if (!private) return -ENOMEM; + private->sch = sch; dev_set_drvdata(&sch->dev, private); mutex_init(&private->state_mutex); - - spin_lock_irq(sch->lock); - private->state = VFIO_CCW_STATE_NOT_OPER; - sch->isc = VFIO_CCW_ISC; - ret = cio_enable_subchannel(sch, (u32)(unsigned long)sch); - spin_unlock_irq(sch->lock); - if (ret) - goto out_free; + INIT_WORK(&private->io_work, vfio_ccw_sch_io_todo); + INIT_WORK(&private->event_work, vfio_ccw_sch_event_todo); + atomic_set(&private->avail, 1); ret = vfio_ccw_mdev_reg(sch); if (ret) - goto out_disable; + goto out_free; - INIT_WORK(&private->io_work, vfio_ccw_sch_io_todo); - INIT_WORK(&private->event_work, vfio_ccw_sch_event_todo); - atomic_set(&private->avail, 1); - private->state = VFIO_CCW_STATE_STANDBY; + vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_INIT); + ret = -EFAULT; + if (private->state != VFIO_CCW_STATE_STANDBY) + goto out_unreg; return 0; -out_disable: - cio_disable_subchannel(sch); +out_unreg: + vfio_ccw_mdev_unreg(sch); out_free: dev_set_drvdata(&sch->dev, NULL); kfree(private); diff --git a/drivers/s390/cio/vfio_ccw_fsm.c b/drivers/s390/cio/vfio_ccw_fsm.c index d85bcfc..e8fe1e6 100644 --- a/drivers/s390/cio/vfio_ccw_fsm.c +++ b/drivers/s390/cio/vfio_ccw_fsm.c @@ -9,6 +9,7 @@ #include <linux/vfio.h> #include <linux/mdev.h> +#include <asm/isc.h> #include "ioasm.h" #include "vfio_ccw_private.h" @@ -167,35 +168,55 @@ static int fsm_sch_event(struct vfio_ccw_private *private) return ret; } +static int fsm_init(struct vfio_ccw_private *private) +{ + struct subchannel *sch = private->sch; + int ret = VFIO_CCW_STATE_STANDBY; + + spin_lock_irq(sch->lock); + sch->isc = VFIO_CCW_ISC; + if (cio_enable_subchannel(sch, (u32)(unsigned long)sch)) + ret = VFIO_CCW_STATE_NOT_OPER; + spin_unlock_irq(sch->lock); + + return ret; +} + + /* * Device statemachine */ fsm_func_t *vfio_ccw_jumptable[NR_VFIO_CCW_STATES][NR_VFIO_CCW_EVENTS] = { [VFIO_CCW_STATE_NOT_OPER] = { + [VFIO_CCW_EVENT_INIT] = fsm_init, [VFIO_CCW_EVENT_NOT_OPER] = fsm_nop, [VFIO_CCW_EVENT_SSCH_REQ] = fsm_io_error, [VFIO_CCW_EVENT_INTERRUPT] = fsm_disabled_irq, [VFIO_CCW_EVENT_SCH_EVENT] = fsm_nop, }, [VFIO_CCW_STATE_STANDBY] = { + [VFIO_CCW_EVENT_INIT] = fsm_nop, [VFIO_CCW_EVENT_NOT_OPER] = fsm_notoper, [VFIO_CCW_EVENT_SSCH_REQ] = fsm_io_error, [VFIO_CCW_EVENT_INTERRUPT] = fsm_irq, [VFIO_CCW_EVENT_SCH_EVENT] = fsm_sch_event, }, [VFIO_CCW_STATE_IDLE] = { + [VFIO_CCW_EVENT_INIT] = fsm_nop, [VFIO_CCW_EVENT_NOT_OPER] = fsm_notoper, [VFIO_CCW_EVENT_SSCH_REQ] = fsm_io_request, [VFIO_CCW_EVENT_INTERRUPT] = fsm_irq, [VFIO_CCW_EVENT_SCH_EVENT] = fsm_sch_event, }, [VFIO_CCW_STATE_BOXED] = { + [VFIO_CCW_EVENT_INIT] = fsm_nop, [VFIO_CCW_EVENT_NOT_OPER] = fsm_notoper, [VFIO_CCW_EVENT_SSCH_REQ] = fsm_io_busy, [VFIO_CCW_EVENT_INTERRUPT] = fsm_irq, [VFIO_CCW_EVENT_SCH_EVENT] = fsm_sch_event, }, [VFIO_CCW_STATE_BUSY] = { + [VFIO_CCW_EVENT_INIT] = fsm_nop, [VFIO_CCW_EVENT_NOT_OPER] = fsm_notoper, [VFIO_CCW_EVENT_SSCH_REQ] = fsm_io_busy, [VFIO_CCW_EVENT_INTERRUPT] = fsm_irq, diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c index dac8ce4..78d1925 100644 --- a/drivers/s390/cio/vfio_ccw_ops.c +++ b/drivers/s390/cio/vfio_ccw_ops.c @@ -111,14 +111,10 @@ static int vfio_ccw_mdev_create(struct kobject *kobj, struct mdev_device *mdev) struct vfio_ccw_private *private = dev_get_drvdata(mdev_parent_dev(mdev)); - if (private->state == VFIO_CCW_STATE_NOT_OPER) - return -ENODEV; - if (atomic_dec_if_positive(&private->avail) < 0) return -EPERM; private->mdev = mdev; - private->state = VFIO_CCW_STATE_IDLE; return 0; } @@ -128,13 +124,6 @@ static int vfio_ccw_mdev_remove(struct mdev_device *mdev) struct vfio_ccw_private *private = dev_get_drvdata(mdev_parent_dev(mdev)); - if ((private->state != VFIO_CCW_STATE_NOT_OPER) && - (private->state != VFIO_CCW_STATE_STANDBY)) { - if (!vfio_ccw_mdev_reset(mdev)) - private->state = VFIO_CCW_STATE_STANDBY; - /* The state will be NOT_OPER on error. */ - } - private->mdev = NULL; atomic_inc(&private->avail); diff --git a/drivers/s390/cio/vfio_ccw_private.h b/drivers/s390/cio/vfio_ccw_private.h index cf197cf..cacf677 100644 --- a/drivers/s390/cio/vfio_ccw_private.h +++ b/drivers/s390/cio/vfio_ccw_private.h @@ -76,6 +76,7 @@ enum vfio_ccw_state { * Asynchronous events of the device statemachine. */ enum vfio_ccw_event { + VFIO_CCW_EVENT_INIT, VFIO_CCW_EVENT_NOT_OPER, VFIO_CCW_EVENT_SSCH_REQ, VFIO_CCW_EVENT_INTERRUPT,
The VFIO_CCW_EVENT_INIT event allows to export the initial state into the FSM. Signed-off-by: Pierre Morel <pmorel@linux.vnet.ibm.com> --- drivers/s390/cio/vfio_ccw_drv.c | 26 +++++++++++--------------- drivers/s390/cio/vfio_ccw_fsm.c | 21 +++++++++++++++++++++ drivers/s390/cio/vfio_ccw_ops.c | 11 ----------- drivers/s390/cio/vfio_ccw_private.h | 1 + 4 files changed, 33 insertions(+), 26 deletions(-)