1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Private stuff for vfio_ccw driver
4 *
5 * Copyright IBM Corp. 2017
6 * Copyright Red Hat, Inc. 2019
7 *
8 * Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
9 *            Xiao Feng Ren <renxiaof@linux.vnet.ibm.com>
10 *            Cornelia Huck <cohuck@redhat.com>
11 */
12
13#ifndef _VFIO_CCW_PRIVATE_H_
14#define _VFIO_CCW_PRIVATE_H_
15
16#include <linux/completion.h>
17#include <linux/eventfd.h>
18#include <linux/workqueue.h>
19#include <linux/vfio_ccw.h>
20#include <asm/crw.h>
21#include <asm/debug.h>
22
23#include "css.h"
24#include "vfio_ccw_cp.h"
25
26#define VFIO_CCW_OFFSET_SHIFT   10
27#define VFIO_CCW_OFFSET_TO_INDEX(off)	(off >> VFIO_CCW_OFFSET_SHIFT)
28#define VFIO_CCW_INDEX_TO_OFFSET(index)	((u64)(index) << VFIO_CCW_OFFSET_SHIFT)
29#define VFIO_CCW_OFFSET_MASK	(((u64)(1) << VFIO_CCW_OFFSET_SHIFT) - 1)
30
31/* capability chain handling similar to vfio-pci */
32struct vfio_ccw_private;
33struct vfio_ccw_region;
34
35struct vfio_ccw_regops {
36	ssize_t	(*read)(struct vfio_ccw_private *private, char __user *buf,
37			size_t count, loff_t *ppos);
38	ssize_t	(*write)(struct vfio_ccw_private *private,
39			 const char __user *buf, size_t count, loff_t *ppos);
40	void	(*release)(struct vfio_ccw_private *private,
41			   struct vfio_ccw_region *region);
42};
43
44struct vfio_ccw_region {
45	u32				type;
46	u32				subtype;
47	const struct vfio_ccw_regops	*ops;
48	void				*data;
49	size_t				size;
50	u32				flags;
51};
52
53int vfio_ccw_register_dev_region(struct vfio_ccw_private *private,
54				 unsigned int subtype,
55				 const struct vfio_ccw_regops *ops,
56				 size_t size, u32 flags, void *data);
57void vfio_ccw_unregister_dev_regions(struct vfio_ccw_private *private);
58
59int vfio_ccw_register_async_dev_regions(struct vfio_ccw_private *private);
60int vfio_ccw_register_schib_dev_regions(struct vfio_ccw_private *private);
61int vfio_ccw_register_crw_dev_regions(struct vfio_ccw_private *private);
62
63struct vfio_ccw_crw {
64	struct list_head	next;
65	struct crw		crw;
66};
67
68/**
69 * struct vfio_ccw_private
70 * @sch: pointer to the subchannel
71 * @state: internal state of the device
72 * @completion: synchronization helper of the I/O completion
73 * @avail: available for creating a mediated device
74 * @mdev: pointer to the mediated device
75 * @nb: notifier for vfio events
76 * @io_region: MMIO region to input/output I/O arguments/results
77 * @io_mutex: protect against concurrent update of I/O regions
78 * @region: additional regions for other subchannel operations
79 * @cmd_region: MMIO region for asynchronous I/O commands other than START
80 * @schib_region: MMIO region for SCHIB information
81 * @crw_region: MMIO region for getting channel report words
82 * @num_regions: number of additional regions
83 * @cp: channel program for the current I/O operation
84 * @irb: irb info received from interrupt
85 * @scsw: scsw info
86 * @io_trigger: eventfd ctx for signaling userspace I/O results
87 * @io_work: work for deferral process of I/O handling
88 */
89struct vfio_ccw_private {
90	struct subchannel	*sch;
91	int			state;
92	struct completion	*completion;
93	atomic_t		avail;
94	struct mdev_device	*mdev;
95	struct notifier_block	nb;
96	struct ccw_io_region	*io_region;
97	struct mutex		io_mutex;
98	struct vfio_ccw_region *region;
99	struct ccw_cmd_region	*cmd_region;
100	struct ccw_schib_region *schib_region;
101	struct ccw_crw_region	*crw_region;
102	int num_regions;
103
104	struct channel_program	cp;
105	struct irb		irb;
106	union scsw		scsw;
107	struct list_head	crw;
108
109	struct eventfd_ctx	*io_trigger;
110	struct eventfd_ctx	*crw_trigger;
111	struct work_struct	io_work;
112	struct work_struct	crw_work;
113} __aligned(8);
114
115extern int vfio_ccw_mdev_reg(struct subchannel *sch);
116extern void vfio_ccw_mdev_unreg(struct subchannel *sch);
117
118extern int vfio_ccw_sch_quiesce(struct subchannel *sch);
119
120/*
121 * States of the device statemachine.
122 */
123enum vfio_ccw_state {
124	VFIO_CCW_STATE_NOT_OPER,
125	VFIO_CCW_STATE_STANDBY,
126	VFIO_CCW_STATE_IDLE,
127	VFIO_CCW_STATE_CP_PROCESSING,
128	VFIO_CCW_STATE_CP_PENDING,
129	/* last element! */
130	NR_VFIO_CCW_STATES
131};
132
133/*
134 * Asynchronous events of the device statemachine.
135 */
136enum vfio_ccw_event {
137	VFIO_CCW_EVENT_NOT_OPER,
138	VFIO_CCW_EVENT_IO_REQ,
139	VFIO_CCW_EVENT_INTERRUPT,
140	VFIO_CCW_EVENT_ASYNC_REQ,
141	/* last element! */
142	NR_VFIO_CCW_EVENTS
143};
144
145/*
146 * Action called through jumptable.
147 */
148typedef void (fsm_func_t)(struct vfio_ccw_private *, enum vfio_ccw_event);
149extern fsm_func_t *vfio_ccw_jumptable[NR_VFIO_CCW_STATES][NR_VFIO_CCW_EVENTS];
150
151static inline void vfio_ccw_fsm_event(struct vfio_ccw_private *private,
152				     int event)
153{
154	trace_vfio_ccw_fsm_event(private->sch->schid, private->state, event);
155	vfio_ccw_jumptable[private->state][event](private, event);
156}
157
158extern struct workqueue_struct *vfio_ccw_work_q;
159
160
161/* s390 debug feature, similar to base cio */
162extern debug_info_t *vfio_ccw_debug_msg_id;
163extern debug_info_t *vfio_ccw_debug_trace_id;
164
165#define VFIO_CCW_TRACE_EVENT(imp, txt) \
166		debug_text_event(vfio_ccw_debug_trace_id, imp, txt)
167
168#define VFIO_CCW_MSG_EVENT(imp, args...) \
169		debug_sprintf_event(vfio_ccw_debug_msg_id, imp, ##args)
170
171static inline void VFIO_CCW_HEX_EVENT(int level, void *data, int length)
172{
173	debug_event(vfio_ccw_debug_trace_id, level, data, length);
174}
175
176#endif
177