mirror of https://gitee.com/openkylin/linux.git
205 lines
4.6 KiB
C
205 lines
4.6 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Finite state machine for vfio-ccw device handling
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*
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* Copyright IBM Corp. 2017
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*
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* Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
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*/
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#include <linux/vfio.h>
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#include <linux/mdev.h>
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#include "ioasm.h"
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#include "vfio_ccw_private.h"
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static int fsm_io_helper(struct vfio_ccw_private *private)
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{
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struct subchannel *sch;
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union orb *orb;
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int ccode;
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__u8 lpm;
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unsigned long flags;
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sch = private->sch;
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spin_lock_irqsave(sch->lock, flags);
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private->state = VFIO_CCW_STATE_BUSY;
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spin_unlock_irqrestore(sch->lock, flags);
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orb = cp_get_orb(&private->cp, (u32)(addr_t)sch, sch->lpm);
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/* Issue "Start Subchannel" */
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ccode = ssch(sch->schid, orb);
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switch (ccode) {
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case 0:
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/*
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* Initialize device status information
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*/
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sch->schib.scsw.cmd.actl |= SCSW_ACTL_START_PEND;
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return 0;
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case 1: /* Status pending */
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case 2: /* Busy */
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return -EBUSY;
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case 3: /* Device/path not operational */
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{
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lpm = orb->cmd.lpm;
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if (lpm != 0)
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sch->lpm &= ~lpm;
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else
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sch->lpm = 0;
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if (cio_update_schib(sch))
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return -ENODEV;
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return sch->lpm ? -EACCES : -ENODEV;
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}
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default:
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return ccode;
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}
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}
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static void fsm_notoper(struct vfio_ccw_private *private,
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enum vfio_ccw_event event)
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{
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struct subchannel *sch = private->sch;
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/*
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* TODO:
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* Probably we should send the machine check to the guest.
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*/
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css_sched_sch_todo(sch, SCH_TODO_UNREG);
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private->state = VFIO_CCW_STATE_NOT_OPER;
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}
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/*
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* No operation action.
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*/
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static void fsm_nop(struct vfio_ccw_private *private,
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enum vfio_ccw_event event)
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{
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}
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static void fsm_io_error(struct vfio_ccw_private *private,
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enum vfio_ccw_event event)
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{
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pr_err("vfio-ccw: FSM: I/O request from state:%d\n", private->state);
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private->io_region.ret_code = -EIO;
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}
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static void fsm_io_busy(struct vfio_ccw_private *private,
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enum vfio_ccw_event event)
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{
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private->io_region.ret_code = -EBUSY;
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}
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static void fsm_disabled_irq(struct vfio_ccw_private *private,
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enum vfio_ccw_event event)
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{
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struct subchannel *sch = private->sch;
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/*
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* An interrupt in a disabled state means a previous disable was not
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* successful - should not happen, but we try to disable again.
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*/
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cio_disable_subchannel(sch);
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}
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/*
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* Deal with the ccw command request from the userspace.
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*/
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static void fsm_io_request(struct vfio_ccw_private *private,
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enum vfio_ccw_event event)
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{
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union orb *orb;
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union scsw *scsw = &private->scsw;
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struct ccw_io_region *io_region = &private->io_region;
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struct mdev_device *mdev = private->mdev;
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private->state = VFIO_CCW_STATE_BOXED;
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memcpy(scsw, io_region->scsw_area, sizeof(*scsw));
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if (scsw->cmd.fctl & SCSW_FCTL_START_FUNC) {
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orb = (union orb *)io_region->orb_area;
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io_region->ret_code = cp_init(&private->cp, mdev_dev(mdev),
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orb);
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if (io_region->ret_code)
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goto err_out;
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io_region->ret_code = cp_prefetch(&private->cp);
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if (io_region->ret_code) {
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cp_free(&private->cp);
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goto err_out;
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}
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/* Start channel program and wait for I/O interrupt. */
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io_region->ret_code = fsm_io_helper(private);
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if (io_region->ret_code) {
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cp_free(&private->cp);
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goto err_out;
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}
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return;
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} else if (scsw->cmd.fctl & SCSW_FCTL_HALT_FUNC) {
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/* XXX: Handle halt. */
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io_region->ret_code = -EOPNOTSUPP;
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goto err_out;
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} else if (scsw->cmd.fctl & SCSW_FCTL_CLEAR_FUNC) {
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/* XXX: Handle clear. */
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io_region->ret_code = -EOPNOTSUPP;
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goto err_out;
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}
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err_out:
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private->state = VFIO_CCW_STATE_IDLE;
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}
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/*
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* Got an interrupt for a normal io (state busy).
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*/
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static void fsm_irq(struct vfio_ccw_private *private,
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enum vfio_ccw_event event)
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{
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struct irb *irb = this_cpu_ptr(&cio_irb);
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memcpy(&private->irb, irb, sizeof(*irb));
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queue_work(vfio_ccw_work_q, &private->io_work);
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if (private->completion)
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complete(private->completion);
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}
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/*
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* Device statemachine
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*/
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fsm_func_t *vfio_ccw_jumptable[NR_VFIO_CCW_STATES][NR_VFIO_CCW_EVENTS] = {
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[VFIO_CCW_STATE_NOT_OPER] = {
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[VFIO_CCW_EVENT_NOT_OPER] = fsm_nop,
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[VFIO_CCW_EVENT_IO_REQ] = fsm_io_error,
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[VFIO_CCW_EVENT_INTERRUPT] = fsm_disabled_irq,
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},
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[VFIO_CCW_STATE_STANDBY] = {
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[VFIO_CCW_EVENT_NOT_OPER] = fsm_notoper,
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[VFIO_CCW_EVENT_IO_REQ] = fsm_io_error,
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[VFIO_CCW_EVENT_INTERRUPT] = fsm_irq,
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},
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[VFIO_CCW_STATE_IDLE] = {
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[VFIO_CCW_EVENT_NOT_OPER] = fsm_notoper,
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[VFIO_CCW_EVENT_IO_REQ] = fsm_io_request,
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[VFIO_CCW_EVENT_INTERRUPT] = fsm_irq,
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},
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[VFIO_CCW_STATE_BOXED] = {
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[VFIO_CCW_EVENT_NOT_OPER] = fsm_notoper,
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[VFIO_CCW_EVENT_IO_REQ] = fsm_io_busy,
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[VFIO_CCW_EVENT_INTERRUPT] = fsm_irq,
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},
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[VFIO_CCW_STATE_BUSY] = {
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[VFIO_CCW_EVENT_NOT_OPER] = fsm_notoper,
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[VFIO_CCW_EVENT_IO_REQ] = fsm_io_busy,
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[VFIO_CCW_EVENT_INTERRUPT] = fsm_irq,
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},
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};
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