// SPDX-License-Identifier: GPL-2.0 /* * VFIO based Physical Subchannel device driver * * Copyright IBM Corp. 2017 * Copyright Red Hat, Inc. 2019 * * Author(s): Dong Jia Shi * Xiao Feng Ren * Cornelia Huck */ #include #include #include #include #include #include #include #include "ioasm.h" #include "css.h" #include "vfio_ccw_private.h" struct workqueue_struct *vfio_ccw_work_q; static struct kmem_cache *vfio_ccw_io_region; static struct kmem_cache *vfio_ccw_cmd_region; debug_info_t *vfio_ccw_debug_msg_id; debug_info_t *vfio_ccw_debug_trace_id; /* * Helpers */ int vfio_ccw_sch_quiesce(struct subchannel *sch) { struct vfio_ccw_private *private = dev_get_drvdata(&sch->dev); DECLARE_COMPLETION_ONSTACK(completion); int iretry, ret = 0; spin_lock_irq(sch->lock); if (!sch->schib.pmcw.ena) goto out_unlock; ret = cio_disable_subchannel(sch); if (ret != -EBUSY) goto out_unlock; iretry = 255; do { ret = cio_cancel_halt_clear(sch, &iretry); if (ret == -EIO) { pr_err("vfio_ccw: could not quiesce subchannel 0.%x.%04x!\n", sch->schid.ssid, sch->schid.sch_no); break; } /* * Flush all I/O and wait for * cancel/halt/clear completion. */ private->completion = &completion; spin_unlock_irq(sch->lock); if (ret == -EBUSY) wait_for_completion_timeout(&completion, 3*HZ); private->completion = NULL; flush_workqueue(vfio_ccw_work_q); spin_lock_irq(sch->lock); ret = cio_disable_subchannel(sch); } while (ret == -EBUSY); out_unlock: private->state = VFIO_CCW_STATE_NOT_OPER; spin_unlock_irq(sch->lock); return ret; } static void vfio_ccw_sch_io_todo(struct work_struct *work) { struct vfio_ccw_private *private; struct irb *irb; bool is_final; private = container_of(work, struct vfio_ccw_private, io_work); irb = &private->irb; is_final = !(scsw_actl(&irb->scsw) & (SCSW_ACTL_DEVACT | SCSW_ACTL_SCHACT)); if (scsw_is_solicited(&irb->scsw)) { cp_update_scsw(&private->cp, &irb->scsw); if (is_final && private->state == VFIO_CCW_STATE_CP_PENDING) cp_free(&private->cp); } mutex_lock(&private->io_mutex); memcpy(private->io_region->irb_area, irb, sizeof(*irb)); mutex_unlock(&private->io_mutex); if (private->mdev && is_final) private->state = VFIO_CCW_STATE_IDLE; if (private->io_trigger) eventfd_signal(private->io_trigger, 1); } /* * Css driver callbacks */ static void vfio_ccw_sch_irq(struct subchannel *sch) { struct vfio_ccw_private *private = dev_get_drvdata(&sch->dev); inc_irq_stat(IRQIO_CIO); vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_INTERRUPT); } static int vfio_ccw_sch_probe(struct subchannel *sch) { struct pmcw *pmcw = &sch->schib.pmcw; struct vfio_ccw_private *private; int ret = -ENOMEM; if (pmcw->qf) { dev_warn(&sch->dev, "vfio: ccw: does not support QDIO: %s\n", dev_name(&sch->dev)); return -ENODEV; } private = kzalloc(sizeof(*private), GFP_KERNEL | GFP_DMA); if (!private) return -ENOMEM; private->cp.guest_cp = kcalloc(CCWCHAIN_LEN_MAX, sizeof(struct ccw1), GFP_KERNEL); if (!private->cp.guest_cp) goto out_free; private->io_region = kmem_cache_zalloc(vfio_ccw_io_region, GFP_KERNEL | GFP_DMA); if (!private->io_region) goto out_free; private->cmd_region = kmem_cache_zalloc(vfio_ccw_cmd_region, GFP_KERNEL | GFP_DMA); if (!private->cmd_region) goto out_free; private->sch = sch; dev_set_drvdata(&sch->dev, private); mutex_init(&private->io_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); atomic_set(&private->avail, 1); private->state = VFIO_CCW_STATE_STANDBY; ret = vfio_ccw_mdev_reg(sch); if (ret) goto out_disable; VFIO_CCW_MSG_EVENT(4, "bound to subchannel %x.%x.%04x\n", sch->schid.cssid, sch->schid.ssid, sch->schid.sch_no); return 0; out_disable: cio_disable_subchannel(sch); out_free: dev_set_drvdata(&sch->dev, NULL); if (private->cmd_region) kmem_cache_free(vfio_ccw_cmd_region, private->cmd_region); if (private->io_region) kmem_cache_free(vfio_ccw_io_region, private->io_region); kfree(private->cp.guest_cp); kfree(private); return ret; } static int vfio_ccw_sch_remove(struct subchannel *sch) { struct vfio_ccw_private *private = dev_get_drvdata(&sch->dev); vfio_ccw_sch_quiesce(sch); vfio_ccw_mdev_unreg(sch); dev_set_drvdata(&sch->dev, NULL); kmem_cache_free(vfio_ccw_cmd_region, private->cmd_region); kmem_cache_free(vfio_ccw_io_region, private->io_region); kfree(private->cp.guest_cp); kfree(private); VFIO_CCW_MSG_EVENT(4, "unbound from subchannel %x.%x.%04x\n", sch->schid.cssid, sch->schid.ssid, sch->schid.sch_no); return 0; } static void vfio_ccw_sch_shutdown(struct subchannel *sch) { vfio_ccw_sch_quiesce(sch); } /** * vfio_ccw_sch_event - process subchannel event * @sch: subchannel * @process: non-zero if function is called in process context * * An unspecified event occurred for this subchannel. Adjust data according * to the current operational state of the subchannel. Return zero when the * event has been handled sufficiently or -EAGAIN when this function should * be called again in process context. */ static int vfio_ccw_sch_event(struct subchannel *sch, int process) { struct vfio_ccw_private *private = dev_get_drvdata(&sch->dev); unsigned long flags; int rc = -EAGAIN; spin_lock_irqsave(sch->lock, flags); if (!device_is_registered(&sch->dev)) goto out_unlock; if (work_pending(&sch->todo_work)) goto out_unlock; if (cio_update_schib(sch)) { vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_NOT_OPER); rc = 0; goto out_unlock; } private = dev_get_drvdata(&sch->dev); if (private->state == VFIO_CCW_STATE_NOT_OPER) { private->state = private->mdev ? VFIO_CCW_STATE_IDLE : VFIO_CCW_STATE_STANDBY; } rc = 0; out_unlock: spin_unlock_irqrestore(sch->lock, flags); return rc; } static struct css_device_id vfio_ccw_sch_ids[] = { { .match_flags = 0x1, .type = SUBCHANNEL_TYPE_IO, }, { /* end of list */ }, }; MODULE_DEVICE_TABLE(css, vfio_ccw_sch_ids); static struct css_driver vfio_ccw_sch_driver = { .drv = { .name = "vfio_ccw", .owner = THIS_MODULE, }, .subchannel_type = vfio_ccw_sch_ids, .irq = vfio_ccw_sch_irq, .probe = vfio_ccw_sch_probe, .remove = vfio_ccw_sch_remove, .shutdown = vfio_ccw_sch_shutdown, .sch_event = vfio_ccw_sch_event, }; static int __init vfio_ccw_debug_init(void) { vfio_ccw_debug_msg_id = debug_register("vfio_ccw_msg", 16, 1, 11 * sizeof(long)); if (!vfio_ccw_debug_msg_id) goto out_unregister; debug_register_view(vfio_ccw_debug_msg_id, &debug_sprintf_view); debug_set_level(vfio_ccw_debug_msg_id, 2); vfio_ccw_debug_trace_id = debug_register("vfio_ccw_trace", 16, 1, 16); if (!vfio_ccw_debug_trace_id) goto out_unregister; debug_register_view(vfio_ccw_debug_trace_id, &debug_hex_ascii_view); debug_set_level(vfio_ccw_debug_trace_id, 2); return 0; out_unregister: debug_unregister(vfio_ccw_debug_msg_id); debug_unregister(vfio_ccw_debug_trace_id); return -1; } static void vfio_ccw_debug_exit(void) { debug_unregister(vfio_ccw_debug_msg_id); debug_unregister(vfio_ccw_debug_trace_id); } static int __init vfio_ccw_sch_init(void) { int ret; ret = vfio_ccw_debug_init(); if (ret) return ret; vfio_ccw_work_q = create_singlethread_workqueue("vfio-ccw"); if (!vfio_ccw_work_q) { ret = -ENOMEM; goto out_err; } vfio_ccw_io_region = kmem_cache_create_usercopy("vfio_ccw_io_region", sizeof(struct ccw_io_region), 0, SLAB_ACCOUNT, 0, sizeof(struct ccw_io_region), NULL); if (!vfio_ccw_io_region) goto out_err; vfio_ccw_cmd_region = kmem_cache_create_usercopy("vfio_ccw_cmd_region", sizeof(struct ccw_cmd_region), 0, SLAB_ACCOUNT, 0, sizeof(struct ccw_cmd_region), NULL); if (!vfio_ccw_cmd_region) goto out_err; isc_register(VFIO_CCW_ISC); ret = css_driver_register(&vfio_ccw_sch_driver); if (ret) { isc_unregister(VFIO_CCW_ISC); goto out_err; } return ret; out_err: kmem_cache_destroy(vfio_ccw_cmd_region); kmem_cache_destroy(vfio_ccw_io_region); destroy_workqueue(vfio_ccw_work_q); vfio_ccw_debug_exit(); return ret; } static void __exit vfio_ccw_sch_exit(void) { css_driver_unregister(&vfio_ccw_sch_driver); isc_unregister(VFIO_CCW_ISC); kmem_cache_destroy(vfio_ccw_io_region); kmem_cache_destroy(vfio_ccw_cmd_region); destroy_workqueue(vfio_ccw_work_q); vfio_ccw_debug_exit(); } module_init(vfio_ccw_sch_init); module_exit(vfio_ccw_sch_exit); MODULE_LICENSE("GPL v2");