diff options
Diffstat (limited to 'drivers/s390/cio/vfio_ccw_fsm.c')
| -rw-r--r-- | drivers/s390/cio/vfio_ccw_fsm.c | 119 |
1 files changed, 117 insertions, 2 deletions
diff --git a/drivers/s390/cio/vfio_ccw_fsm.c b/drivers/s390/cio/vfio_ccw_fsm.c index b4a141fbd1a8..49d9d3da0282 100644 --- a/drivers/s390/cio/vfio_ccw_fsm.c +++ b/drivers/s390/cio/vfio_ccw_fsm.c @@ -3,8 +3,10 @@ * Finite state machine for vfio-ccw device handling * * Copyright IBM Corp. 2017 + * Copyright Red Hat, Inc. 2019 * * Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com> + * Cornelia Huck <cohuck@redhat.com> */ #include <linux/vfio.h> @@ -73,6 +75,75 @@ out: return ret; } +static int fsm_do_halt(struct vfio_ccw_private *private) +{ + struct subchannel *sch; + unsigned long flags; + int ccode; + int ret; + + sch = private->sch; + + spin_lock_irqsave(sch->lock, flags); + + /* Issue "Halt Subchannel" */ + ccode = hsch(sch->schid); + + switch (ccode) { + case 0: + /* + * Initialize device status information + */ + sch->schib.scsw.cmd.actl |= SCSW_ACTL_HALT_PEND; + ret = 0; + break; + case 1: /* Status pending */ + case 2: /* Busy */ + ret = -EBUSY; + break; + case 3: /* Device not operational */ + ret = -ENODEV; + break; + default: + ret = ccode; + } + spin_unlock_irqrestore(sch->lock, flags); + return ret; +} + +static int fsm_do_clear(struct vfio_ccw_private *private) +{ + struct subchannel *sch; + unsigned long flags; + int ccode; + int ret; + + sch = private->sch; + + spin_lock_irqsave(sch->lock, flags); + + /* Issue "Clear Subchannel" */ + ccode = csch(sch->schid); + + switch (ccode) { + case 0: + /* + * Initialize device status information + */ + sch->schib.scsw.cmd.actl = SCSW_ACTL_CLEAR_PEND; + /* TODO: check what else we might need to clear */ + ret = 0; + break; + case 3: /* Device not operational */ + ret = -ENODEV; + break; + default: + ret = ccode; + } + spin_unlock_irqrestore(sch->lock, flags); + return ret; +} + static void fsm_notoper(struct vfio_ccw_private *private, enum vfio_ccw_event event) { @@ -113,6 +184,24 @@ static void fsm_io_retry(struct vfio_ccw_private *private, private->io_region->ret_code = -EAGAIN; } +static void fsm_async_error(struct vfio_ccw_private *private, + enum vfio_ccw_event event) +{ + struct ccw_cmd_region *cmd_region = private->cmd_region; + + pr_err("vfio-ccw: FSM: %s request from state:%d\n", + cmd_region->command == VFIO_CCW_ASYNC_CMD_HSCH ? "halt" : + cmd_region->command == VFIO_CCW_ASYNC_CMD_CSCH ? "clear" : + "<unknown>", private->state); + cmd_region->ret_code = -EIO; +} + +static void fsm_async_retry(struct vfio_ccw_private *private, + enum vfio_ccw_event event) +{ + private->cmd_region->ret_code = -EAGAIN; +} + static void fsm_disabled_irq(struct vfio_ccw_private *private, enum vfio_ccw_event event) { @@ -176,11 +265,11 @@ static void fsm_io_request(struct vfio_ccw_private *private, } return; } else if (scsw->cmd.fctl & SCSW_FCTL_HALT_FUNC) { - /* XXX: Handle halt. */ + /* halt is handled via the async cmd region */ io_region->ret_code = -EOPNOTSUPP; goto err_out; } else if (scsw->cmd.fctl & SCSW_FCTL_CLEAR_FUNC) { - /* XXX: Handle clear. */ + /* clear is handled via the async cmd region */ io_region->ret_code = -EOPNOTSUPP; goto err_out; } @@ -191,6 +280,27 @@ err_out: } /* + * Deal with an async request from userspace. + */ +static void fsm_async_request(struct vfio_ccw_private *private, + enum vfio_ccw_event event) +{ + struct ccw_cmd_region *cmd_region = private->cmd_region; + + switch (cmd_region->command) { + case VFIO_CCW_ASYNC_CMD_HSCH: + cmd_region->ret_code = fsm_do_halt(private); + break; + case VFIO_CCW_ASYNC_CMD_CSCH: + cmd_region->ret_code = fsm_do_clear(private); + break; + default: + /* should not happen? */ + cmd_region->ret_code = -EINVAL; + } +} + +/* * Got an interrupt for a normal io (state busy). */ static void fsm_irq(struct vfio_ccw_private *private, @@ -213,26 +323,31 @@ fsm_func_t *vfio_ccw_jumptable[NR_VFIO_CCW_STATES][NR_VFIO_CCW_EVENTS] = { [VFIO_CCW_STATE_NOT_OPER] = { [VFIO_CCW_EVENT_NOT_OPER] = fsm_nop, [VFIO_CCW_EVENT_IO_REQ] = fsm_io_error, + [VFIO_CCW_EVENT_ASYNC_REQ] = fsm_async_error, [VFIO_CCW_EVENT_INTERRUPT] = fsm_disabled_irq, }, [VFIO_CCW_STATE_STANDBY] = { [VFIO_CCW_EVENT_NOT_OPER] = fsm_notoper, [VFIO_CCW_EVENT_IO_REQ] = fsm_io_error, + [VFIO_CCW_EVENT_ASYNC_REQ] = fsm_async_error, [VFIO_CCW_EVENT_INTERRUPT] = fsm_irq, }, [VFIO_CCW_STATE_IDLE] = { [VFIO_CCW_EVENT_NOT_OPER] = fsm_notoper, [VFIO_CCW_EVENT_IO_REQ] = fsm_io_request, + [VFIO_CCW_EVENT_ASYNC_REQ] = fsm_async_request, [VFIO_CCW_EVENT_INTERRUPT] = fsm_irq, }, [VFIO_CCW_STATE_CP_PROCESSING] = { [VFIO_CCW_EVENT_NOT_OPER] = fsm_notoper, [VFIO_CCW_EVENT_IO_REQ] = fsm_io_retry, + [VFIO_CCW_EVENT_ASYNC_REQ] = fsm_async_retry, [VFIO_CCW_EVENT_INTERRUPT] = fsm_irq, }, [VFIO_CCW_STATE_CP_PENDING] = { [VFIO_CCW_EVENT_NOT_OPER] = fsm_notoper, [VFIO_CCW_EVENT_IO_REQ] = fsm_io_busy, + [VFIO_CCW_EVENT_ASYNC_REQ] = fsm_async_request, [VFIO_CCW_EVENT_INTERRUPT] = fsm_irq, }, }; |