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 */
32 struct vfio_ccw_private;
33 struct vfio_ccw_region;
34 
35 struct 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 
44 struct 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 
53 int 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);
57 void vfio_ccw_unregister_dev_regions(struct vfio_ccw_private *private);
58 
59 int vfio_ccw_register_async_dev_regions(struct vfio_ccw_private *private);
60 int vfio_ccw_register_schib_dev_regions(struct vfio_ccw_private *private);
61 int vfio_ccw_register_crw_dev_regions(struct vfio_ccw_private *private);
62 
63 struct 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  */
89 struct 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 
115 extern int vfio_ccw_mdev_reg(struct subchannel *sch);
116 extern void vfio_ccw_mdev_unreg(struct subchannel *sch);
117 
118 extern int vfio_ccw_sch_quiesce(struct subchannel *sch);
119 
120 /*
121  * States of the device statemachine.
122  */
123 enum 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  */
136 enum 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  */
148 typedef void (fsm_func_t)(struct vfio_ccw_private *, enum vfio_ccw_event);
149 extern fsm_func_t *vfio_ccw_jumptable[NR_VFIO_CCW_STATES][NR_VFIO_CCW_EVENTS];
150 
151 static 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 
158 extern struct workqueue_struct *vfio_ccw_work_q;
159 
160 
161 /* s390 debug feature, similar to base cio */
162 extern debug_info_t *vfio_ccw_debug_msg_id;
163 extern 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 
171 static 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