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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/s390/cio/vfio_ccw_fsm.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/s390/cio/vfio_ccw_fsm.c')
-rw-r--r-- | drivers/s390/cio/vfio_ccw_fsm.c | 468 |
1 files changed, 468 insertions, 0 deletions
diff --git a/drivers/s390/cio/vfio_ccw_fsm.c b/drivers/s390/cio/vfio_ccw_fsm.c new file mode 100644 index 000000000..a59c75886 --- /dev/null +++ b/drivers/s390/cio/vfio_ccw_fsm.c @@ -0,0 +1,468 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * 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> + +#include <asm/isc.h> + +#include "ioasm.h" +#include "vfio_ccw_private.h" + +static int fsm_io_helper(struct vfio_ccw_private *private) +{ + struct subchannel *sch; + union orb *orb; + int ccode; + __u8 lpm; + unsigned long flags; + int ret; + + sch = private->sch; + + spin_lock_irqsave(sch->lock, flags); + + orb = cp_get_orb(&private->cp, (u32)(addr_t)sch, sch->lpm); + if (!orb) { + ret = -EIO; + goto out; + } + + VFIO_CCW_TRACE_EVENT(5, "stIO"); + VFIO_CCW_TRACE_EVENT(5, dev_name(&sch->dev)); + + /* Issue "Start Subchannel" */ + ccode = ssch(sch->schid, orb); + + VFIO_CCW_HEX_EVENT(5, &ccode, sizeof(ccode)); + + switch (ccode) { + case 0: + /* + * Initialize device status information + */ + sch->schib.scsw.cmd.actl |= SCSW_ACTL_START_PEND; + ret = 0; + private->state = VFIO_CCW_STATE_CP_PENDING; + break; + case 1: /* Status pending */ + case 2: /* Busy */ + ret = -EBUSY; + break; + case 3: /* Device/path not operational */ + { + lpm = orb->cmd.lpm; + if (lpm != 0) + sch->lpm &= ~lpm; + else + sch->lpm = 0; + + if (cio_update_schib(sch)) + ret = -ENODEV; + else + ret = sch->lpm ? -EACCES : -ENODEV; + break; + } + default: + ret = ccode; + } +out: + spin_unlock_irqrestore(sch->lock, flags); + 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); + + VFIO_CCW_TRACE_EVENT(2, "haltIO"); + VFIO_CCW_TRACE_EVENT(2, dev_name(&sch->dev)); + + /* Issue "Halt Subchannel" */ + ccode = hsch(sch->schid); + + VFIO_CCW_HEX_EVENT(2, &ccode, sizeof(ccode)); + + 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); + + VFIO_CCW_TRACE_EVENT(2, "clearIO"); + VFIO_CCW_TRACE_EVENT(2, dev_name(&sch->dev)); + + /* Issue "Clear Subchannel" */ + ccode = csch(sch->schid); + + VFIO_CCW_HEX_EVENT(2, &ccode, sizeof(ccode)); + + 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) +{ + struct subchannel *sch = private->sch; + + VFIO_CCW_MSG_EVENT(2, "sch %x.%x.%04x: notoper event %x state %x\n", + sch->schid.cssid, + sch->schid.ssid, + sch->schid.sch_no, + event, + private->state); + + /* + * TODO: + * Probably we should send the machine check to the guest. + */ + css_sched_sch_todo(sch, SCH_TODO_UNREG); + private->state = VFIO_CCW_STATE_NOT_OPER; + + /* This is usually handled during CLOSE event */ + cp_free(&private->cp); +} + +/* + * No operation action. + */ +static void fsm_nop(struct vfio_ccw_private *private, + enum vfio_ccw_event event) +{ +} + +static void fsm_io_error(struct vfio_ccw_private *private, + enum vfio_ccw_event event) +{ + pr_err("vfio-ccw: FSM: I/O request from state:%d\n", private->state); + private->io_region->ret_code = -EIO; +} + +static void fsm_io_busy(struct vfio_ccw_private *private, + enum vfio_ccw_event event) +{ + private->io_region->ret_code = -EBUSY; +} + +static void fsm_io_retry(struct vfio_ccw_private *private, + enum vfio_ccw_event event) +{ + 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) +{ + struct subchannel *sch = private->sch; + + /* + * An interrupt in a disabled state means a previous disable was not + * successful - should not happen, but we try to disable again. + */ + cio_disable_subchannel(sch); +} +inline struct subchannel_id get_schid(struct vfio_ccw_private *p) +{ + return p->sch->schid; +} + +/* + * Deal with the ccw command request from the userspace. + */ +static void fsm_io_request(struct vfio_ccw_private *private, + enum vfio_ccw_event event) +{ + union orb *orb; + union scsw *scsw = &private->scsw; + struct ccw_io_region *io_region = private->io_region; + char *errstr = "request"; + struct subchannel_id schid = get_schid(private); + + private->state = VFIO_CCW_STATE_CP_PROCESSING; + memcpy(scsw, io_region->scsw_area, sizeof(*scsw)); + + if (scsw->cmd.fctl & SCSW_FCTL_START_FUNC) { + orb = (union orb *)io_region->orb_area; + + /* Don't try to build a cp if transport mode is specified. */ + if (orb->tm.b) { + io_region->ret_code = -EOPNOTSUPP; + VFIO_CCW_MSG_EVENT(2, + "sch %x.%x.%04x: transport mode\n", + schid.cssid, + schid.ssid, schid.sch_no); + errstr = "transport mode"; + goto err_out; + } + io_region->ret_code = cp_init(&private->cp, orb); + if (io_region->ret_code) { + VFIO_CCW_MSG_EVENT(2, + "sch %x.%x.%04x: cp_init=%d\n", + schid.cssid, + schid.ssid, schid.sch_no, + io_region->ret_code); + errstr = "cp init"; + goto err_out; + } + + io_region->ret_code = cp_prefetch(&private->cp); + if (io_region->ret_code) { + VFIO_CCW_MSG_EVENT(2, + "sch %x.%x.%04x: cp_prefetch=%d\n", + schid.cssid, + schid.ssid, schid.sch_no, + io_region->ret_code); + errstr = "cp prefetch"; + cp_free(&private->cp); + goto err_out; + } + + /* Start channel program and wait for I/O interrupt. */ + io_region->ret_code = fsm_io_helper(private); + if (io_region->ret_code) { + VFIO_CCW_MSG_EVENT(2, + "sch %x.%x.%04x: fsm_io_helper=%d\n", + schid.cssid, + schid.ssid, schid.sch_no, + io_region->ret_code); + errstr = "cp fsm_io_helper"; + cp_free(&private->cp); + goto err_out; + } + return; + } else if (scsw->cmd.fctl & SCSW_FCTL_HALT_FUNC) { + VFIO_CCW_MSG_EVENT(2, + "sch %x.%x.%04x: halt on io_region\n", + schid.cssid, + schid.ssid, schid.sch_no); + /* 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) { + VFIO_CCW_MSG_EVENT(2, + "sch %x.%x.%04x: clear on io_region\n", + schid.cssid, + schid.ssid, schid.sch_no); + /* clear is handled via the async cmd region */ + io_region->ret_code = -EOPNOTSUPP; + goto err_out; + } + +err_out: + private->state = VFIO_CCW_STATE_IDLE; + trace_vfio_ccw_fsm_io_request(scsw->cmd.fctl, schid, + io_region->ret_code, errstr); +} + +/* + * 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; + } + + trace_vfio_ccw_fsm_async_request(get_schid(private), + cmd_region->command, + cmd_region->ret_code); +} + +/* + * Got an interrupt for a normal io (state busy). + */ +static void fsm_irq(struct vfio_ccw_private *private, + enum vfio_ccw_event event) +{ + struct irb *irb = this_cpu_ptr(&cio_irb); + + VFIO_CCW_TRACE_EVENT(6, "IRQ"); + VFIO_CCW_TRACE_EVENT(6, dev_name(&private->sch->dev)); + + memcpy(&private->irb, irb, sizeof(*irb)); + + queue_work(vfio_ccw_work_q, &private->io_work); + + if (private->completion) + complete(private->completion); +} + +static void fsm_open(struct vfio_ccw_private *private, + enum vfio_ccw_event event) +{ + struct subchannel *sch = private->sch; + int ret; + + spin_lock_irq(sch->lock); + sch->isc = VFIO_CCW_ISC; + ret = cio_enable_subchannel(sch, (u32)(unsigned long)sch); + if (ret) + goto err_unlock; + + private->state = VFIO_CCW_STATE_IDLE; + spin_unlock_irq(sch->lock); + return; + +err_unlock: + spin_unlock_irq(sch->lock); + vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_NOT_OPER); +} + +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 err_unlock; + + ret = cio_disable_subchannel(sch); + if (ret == -EBUSY) + ret = vfio_ccw_sch_quiesce(sch); + if (ret) + goto err_unlock; + + private->state = VFIO_CCW_STATE_STANDBY; + spin_unlock_irq(sch->lock); + cp_free(&private->cp); + return; + +err_unlock: + spin_unlock_irq(sch->lock); + vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_NOT_OPER); +} + +/* + * Device statemachine + */ +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_EVENT_OPEN] = fsm_nop, + [VFIO_CCW_EVENT_CLOSE] = fsm_nop, + }, + [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_disabled_irq, + [VFIO_CCW_EVENT_OPEN] = fsm_open, + [VFIO_CCW_EVENT_CLOSE] = fsm_notoper, + }, + [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_EVENT_OPEN] = fsm_notoper, + [VFIO_CCW_EVENT_CLOSE] = fsm_close, + }, + [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_EVENT_OPEN] = fsm_notoper, + [VFIO_CCW_EVENT_CLOSE] = fsm_close, + }, + [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, + [VFIO_CCW_EVENT_OPEN] = fsm_notoper, + [VFIO_CCW_EVENT_CLOSE] = fsm_close, + }, +}; |