1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Private stuff for vfio_ccw driver
4  *
5  * Copyright IBM Corp. 2017
6  *
7  * Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
8  *            Xiao Feng Ren <renxiaof@linux.vnet.ibm.com>
9  */
10 
11 #ifndef _VFIO_CCW_PRIVATE_H_
12 #define _VFIO_CCW_PRIVATE_H_
13 
14 #include <linux/completion.h>
15 #include <linux/eventfd.h>
16 #include <linux/workqueue.h>
17 #include <linux/vfio_ccw.h>
18 
19 #include "css.h"
20 #include "vfio_ccw_cp.h"
21 
22 /**
23  * struct vfio_ccw_private
24  * @sch: pointer to the subchannel
25  * @state: internal state of the device
26  * @completion: synchronization helper of the I/O completion
27  * @avail: available for creating a mediated device
28  * @mdev: pointer to the mediated device
29  * @nb: notifier for vfio events
30  * @io_region: MMIO region to input/output I/O arguments/results
31  * @cp: channel program for the current I/O operation
32  * @irb: irb info received from interrupt
33  * @scsw: scsw info
34  * @io_trigger: eventfd ctx for signaling userspace I/O results
35  * @io_work: work for deferral process of I/O handling
36  */
37 struct vfio_ccw_private {
38 	struct subchannel	*sch;
39 	int			state;
40 	struct completion	*completion;
41 	atomic_t		avail;
42 	struct mdev_device	*mdev;
43 	struct notifier_block	nb;
44 	struct ccw_io_region	*io_region;
45 
46 	struct channel_program	cp;
47 	struct irb		irb;
48 	union scsw		scsw;
49 
50 	struct eventfd_ctx	*io_trigger;
51 	struct work_struct	io_work;
52 } __aligned(8);
53 
54 extern int vfio_ccw_mdev_reg(struct subchannel *sch);
55 extern void vfio_ccw_mdev_unreg(struct subchannel *sch);
56 
57 extern int vfio_ccw_sch_quiesce(struct subchannel *sch);
58 
59 /*
60  * States of the device statemachine.
61  */
62 enum vfio_ccw_state {
63 	VFIO_CCW_STATE_NOT_OPER,
64 	VFIO_CCW_STATE_STANDBY,
65 	VFIO_CCW_STATE_IDLE,
66 	VFIO_CCW_STATE_BOXED,
67 	VFIO_CCW_STATE_BUSY,
68 	/* last element! */
69 	NR_VFIO_CCW_STATES
70 };
71 
72 /*
73  * Asynchronous events of the device statemachine.
74  */
75 enum vfio_ccw_event {
76 	VFIO_CCW_EVENT_NOT_OPER,
77 	VFIO_CCW_EVENT_IO_REQ,
78 	VFIO_CCW_EVENT_INTERRUPT,
79 	/* last element! */
80 	NR_VFIO_CCW_EVENTS
81 };
82 
83 /*
84  * Action called through jumptable.
85  */
86 typedef void (fsm_func_t)(struct vfio_ccw_private *, enum vfio_ccw_event);
87 extern fsm_func_t *vfio_ccw_jumptable[NR_VFIO_CCW_STATES][NR_VFIO_CCW_EVENTS];
88 
89 static inline void vfio_ccw_fsm_event(struct vfio_ccw_private *private,
90 				     int event)
91 {
92 	vfio_ccw_jumptable[private->state][event](private, event);
93 }
94 
95 extern struct workqueue_struct *vfio_ccw_work_q;
96 
97 #endif
98