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path: root/drivers/s390/cio/vfio_ccw_fsm.c
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Diffstat (limited to 'drivers/s390/cio/vfio_ccw_fsm.c')
-rw-r--r--drivers/s390/cio/vfio_ccw_fsm.c143
1 files changed, 136 insertions, 7 deletions
diff --git a/drivers/s390/cio/vfio_ccw_fsm.c b/drivers/s390/cio/vfio_ccw_fsm.c
index cab17865aafe..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>
@@ -28,9 +30,12 @@ static int fsm_io_helper(struct vfio_ccw_private *private)
sch = private->sch;
spin_lock_irqsave(sch->lock, flags);
- private->state = VFIO_CCW_STATE_BUSY;
orb = cp_get_orb(&private->cp, (u32)(addr_t)sch, sch->lpm);
+ if (!orb) {
+ ret = -EIO;
+ goto out;
+ }
/* Issue "Start Subchannel" */
ccode = ssch(sch->schid, orb);
@@ -42,6 +47,7 @@ static int fsm_io_helper(struct vfio_ccw_private *private)
*/
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 */
@@ -64,6 +70,76 @@ static int fsm_io_helper(struct vfio_ccw_private *private)
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);
+
+ /* 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;
}
@@ -102,6 +178,30 @@ static void fsm_io_busy(struct vfio_ccw_private *private,
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)
{
@@ -130,8 +230,7 @@ static void fsm_io_request(struct vfio_ccw_private *private,
struct mdev_device *mdev = private->mdev;
char *errstr = "request";
- private->state = VFIO_CCW_STATE_BUSY;
-
+ private->state = VFIO_CCW_STATE_CP_PROCESSING;
memcpy(scsw, io_region->scsw_area, sizeof(*scsw));
if (scsw->cmd.fctl & SCSW_FCTL_START_FUNC) {
@@ -166,22 +265,42 @@ 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;
}
err_out:
- private->state = VFIO_CCW_STATE_IDLE;
trace_vfio_ccw_io_fctl(scsw->cmd.fctl, get_schid(private),
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;
+ }
+}
+
+/*
* Got an interrupt for a normal io (state busy).
*/
static void fsm_irq(struct vfio_ccw_private *private,
@@ -204,21 +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_BUSY] = {
+ [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,
},
};
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-21 17:12:34 +0100