1 // SPDX-License-Identifier: GPL-2.0
3 * VFIO based Physical Subchannel device driver
5 * Copyright IBM Corp. 2017
7 * Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
8 * Xiao Feng Ren <renxiaof@linux.vnet.ibm.com>
11 #include <linux/module.h>
12 #include <linux/init.h>
13 #include <linux/device.h>
14 #include <linux/slab.h>
15 #include <linux/uuid.h>
16 #include <linux/mdev.h>
22 #include "vfio_ccw_private.h"
24 struct workqueue_struct *vfio_ccw_work_q;
29 int vfio_ccw_sch_quiesce(struct subchannel *sch)
31 struct vfio_ccw_private *private = dev_get_drvdata(&sch->dev);
32 DECLARE_COMPLETION_ONSTACK(completion);
35 spin_lock_irq(sch->lock);
36 if (!sch->schib.pmcw.ena)
38 ret = cio_disable_subchannel(sch);
45 ret = cio_cancel_halt_clear(sch, &iretry);
46 while (ret == -EBUSY) {
48 * Flush all I/O and wait for
49 * cancel/halt/clear completion.
51 private->completion = &completion;
52 spin_unlock_irq(sch->lock);
54 wait_for_completion_timeout(&completion, 3*HZ);
56 spin_lock_irq(sch->lock);
57 private->completion = NULL;
58 flush_workqueue(vfio_ccw_work_q);
59 ret = cio_cancel_halt_clear(sch, &iretry);
62 ret = cio_disable_subchannel(sch);
63 } while (ret == -EBUSY);
65 private->state = VFIO_CCW_STATE_NOT_OPER;
66 spin_unlock_irq(sch->lock);
70 static void vfio_ccw_sch_io_todo(struct work_struct *work)
72 struct vfio_ccw_private *private;
75 private = container_of(work, struct vfio_ccw_private, io_work);
78 if (scsw_is_solicited(&irb->scsw)) {
79 cp_update_scsw(&private->cp, &irb->scsw);
80 cp_free(&private->cp);
82 memcpy(private->io_region.irb_area, irb, sizeof(*irb));
84 if (private->io_trigger)
85 eventfd_signal(private->io_trigger, 1);
88 private->state = VFIO_CCW_STATE_IDLE;
92 * Css driver callbacks
94 static void vfio_ccw_sch_irq(struct subchannel *sch)
96 struct vfio_ccw_private *private = dev_get_drvdata(&sch->dev);
98 inc_irq_stat(IRQIO_CIO);
99 vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_INTERRUPT);
102 static int vfio_ccw_sch_probe(struct subchannel *sch)
104 struct pmcw *pmcw = &sch->schib.pmcw;
105 struct vfio_ccw_private *private;
109 dev_warn(&sch->dev, "vfio: ccw: does not support QDIO: %s\n",
110 dev_name(&sch->dev));
114 private = kzalloc(sizeof(*private), GFP_KERNEL | GFP_DMA);
118 dev_set_drvdata(&sch->dev, private);
120 spin_lock_irq(sch->lock);
121 private->state = VFIO_CCW_STATE_NOT_OPER;
122 sch->isc = VFIO_CCW_ISC;
123 ret = cio_enable_subchannel(sch, (u32)(unsigned long)sch);
124 spin_unlock_irq(sch->lock);
128 ret = vfio_ccw_mdev_reg(sch);
132 INIT_WORK(&private->io_work, vfio_ccw_sch_io_todo);
133 atomic_set(&private->avail, 1);
134 private->state = VFIO_CCW_STATE_STANDBY;
139 cio_disable_subchannel(sch);
141 dev_set_drvdata(&sch->dev, NULL);
146 static int vfio_ccw_sch_remove(struct subchannel *sch)
148 struct vfio_ccw_private *private = dev_get_drvdata(&sch->dev);
150 vfio_ccw_sch_quiesce(sch);
152 vfio_ccw_mdev_unreg(sch);
154 dev_set_drvdata(&sch->dev, NULL);
161 static void vfio_ccw_sch_shutdown(struct subchannel *sch)
163 vfio_ccw_sch_quiesce(sch);
167 * vfio_ccw_sch_event - process subchannel event
169 * @process: non-zero if function is called in process context
171 * An unspecified event occurred for this subchannel. Adjust data according
172 * to the current operational state of the subchannel. Return zero when the
173 * event has been handled sufficiently or -EAGAIN when this function should
174 * be called again in process context.
176 static int vfio_ccw_sch_event(struct subchannel *sch, int process)
178 struct vfio_ccw_private *private = dev_get_drvdata(&sch->dev);
181 spin_lock_irqsave(sch->lock, flags);
182 if (!device_is_registered(&sch->dev))
185 if (work_pending(&sch->todo_work))
188 if (cio_update_schib(sch)) {
189 vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_NOT_OPER);
193 private = dev_get_drvdata(&sch->dev);
194 if (private->state == VFIO_CCW_STATE_NOT_OPER) {
195 private->state = private->mdev ? VFIO_CCW_STATE_IDLE :
196 VFIO_CCW_STATE_STANDBY;
200 spin_unlock_irqrestore(sch->lock, flags);
205 static struct css_device_id vfio_ccw_sch_ids[] = {
206 { .match_flags = 0x1, .type = SUBCHANNEL_TYPE_IO, },
207 { /* end of list */ },
209 MODULE_DEVICE_TABLE(css, vfio_ccw_sch_ids);
211 static struct css_driver vfio_ccw_sch_driver = {
214 .owner = THIS_MODULE,
216 .subchannel_type = vfio_ccw_sch_ids,
217 .irq = vfio_ccw_sch_irq,
218 .probe = vfio_ccw_sch_probe,
219 .remove = vfio_ccw_sch_remove,
220 .shutdown = vfio_ccw_sch_shutdown,
221 .sch_event = vfio_ccw_sch_event,
224 static int __init vfio_ccw_sch_init(void)
228 vfio_ccw_work_q = create_singlethread_workqueue("vfio-ccw");
229 if (!vfio_ccw_work_q)
232 isc_register(VFIO_CCW_ISC);
233 ret = css_driver_register(&vfio_ccw_sch_driver);
235 isc_unregister(VFIO_CCW_ISC);
236 destroy_workqueue(vfio_ccw_work_q);
242 static void __exit vfio_ccw_sch_exit(void)
244 css_driver_unregister(&vfio_ccw_sch_driver);
245 isc_unregister(VFIO_CCW_ISC);
246 destroy_workqueue(vfio_ccw_work_q);
248 module_init(vfio_ccw_sch_init);
249 module_exit(vfio_ccw_sch_exit);
251 MODULE_LICENSE("GPL v2");