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 <linux/vfio.h>
21 #include <linux/mdev.h>
22 #include <asm/crw.h>
23 #include <asm/debug.h>
24 
25 #include "css.h"
26 #include "vfio_ccw_cp.h"
27 
28 #define VFIO_CCW_OFFSET_SHIFT   10
29 #define VFIO_CCW_OFFSET_TO_INDEX(off)	(off >> VFIO_CCW_OFFSET_SHIFT)
30 #define VFIO_CCW_INDEX_TO_OFFSET(index)	((u64)(index) << VFIO_CCW_OFFSET_SHIFT)
31 #define VFIO_CCW_OFFSET_MASK	(((u64)(1) << VFIO_CCW_OFFSET_SHIFT) - 1)
32 
33 /* capability chain handling similar to vfio-pci */
34 struct vfio_ccw_private;
35 struct vfio_ccw_region;
36 
37 struct vfio_ccw_regops {
38 	ssize_t	(*read)(struct vfio_ccw_private *private, char __user *buf,
39 			size_t count, loff_t *ppos);
40 	ssize_t	(*write)(struct vfio_ccw_private *private,
41 			 const char __user *buf, size_t count, loff_t *ppos);
42 	void	(*release)(struct vfio_ccw_private *private,
43 			   struct vfio_ccw_region *region);
44 };
45 
46 struct vfio_ccw_region {
47 	u32				type;
48 	u32				subtype;
49 	const struct vfio_ccw_regops	*ops;
50 	void				*data;
51 	size_t				size;
52 	u32				flags;
53 };
54 
55 int vfio_ccw_register_dev_region(struct vfio_ccw_private *private,
56 				 unsigned int subtype,
57 				 const struct vfio_ccw_regops *ops,
58 				 size_t size, u32 flags, void *data);
59 void vfio_ccw_unregister_dev_regions(struct vfio_ccw_private *private);
60 
61 int vfio_ccw_register_async_dev_regions(struct vfio_ccw_private *private);
62 int vfio_ccw_register_schib_dev_regions(struct vfio_ccw_private *private);
63 int vfio_ccw_register_crw_dev_regions(struct vfio_ccw_private *private);
64 
65 struct vfio_ccw_crw {
66 	struct list_head	next;
67 	struct crw		crw;
68 };
69 
70 /**
71  * struct vfio_ccw_private
72  * @vdev: Embedded VFIO device
73  * @sch: pointer to the subchannel
74  * @state: internal state of the device
75  * @completion: synchronization helper of the I/O completion
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  * @crw_trigger: eventfd ctx for signaling userspace CRW information
88  * @req_trigger: eventfd ctx for signaling userspace to return device
89  * @io_work: work for deferral process of I/O handling
90  * @crw_work: work for deferral process of CRW handling
91  * @release_comp: synchronization helper for vfio device release
92  * @parent: parent data structures for mdevs created
93  */
94 struct vfio_ccw_private {
95 	struct vfio_device vdev;
96 	struct subchannel	*sch;
97 	int			state;
98 	struct completion	*completion;
99 	struct ccw_io_region	*io_region;
100 	struct mutex		io_mutex;
101 	struct vfio_ccw_region *region;
102 	struct ccw_cmd_region	*cmd_region;
103 	struct ccw_schib_region *schib_region;
104 	struct ccw_crw_region	*crw_region;
105 	int num_regions;
106 
107 	struct channel_program	cp;
108 	struct irb		irb;
109 	union scsw		scsw;
110 	struct list_head	crw;
111 
112 	struct eventfd_ctx	*io_trigger;
113 	struct eventfd_ctx	*crw_trigger;
114 	struct eventfd_ctx	*req_trigger;
115 	struct work_struct	io_work;
116 	struct work_struct	crw_work;
117 
118 	struct completion	release_comp;
119 
120 	struct mdev_parent	parent;
121 	struct mdev_type	mdev_type;
122 	struct mdev_type	*mdev_types[1];
123 } __aligned(8);
124 
125 int vfio_ccw_sch_quiesce(struct subchannel *sch);
126 
127 extern struct mdev_driver vfio_ccw_mdev_driver;
128 
129 /*
130  * States of the device statemachine.
131  */
132 enum vfio_ccw_state {
133 	VFIO_CCW_STATE_NOT_OPER,
134 	VFIO_CCW_STATE_STANDBY,
135 	VFIO_CCW_STATE_IDLE,
136 	VFIO_CCW_STATE_CP_PROCESSING,
137 	VFIO_CCW_STATE_CP_PENDING,
138 	/* last element! */
139 	NR_VFIO_CCW_STATES
140 };
141 
142 /*
143  * Asynchronous events of the device statemachine.
144  */
145 enum vfio_ccw_event {
146 	VFIO_CCW_EVENT_NOT_OPER,
147 	VFIO_CCW_EVENT_IO_REQ,
148 	VFIO_CCW_EVENT_INTERRUPT,
149 	VFIO_CCW_EVENT_ASYNC_REQ,
150 	VFIO_CCW_EVENT_OPEN,
151 	VFIO_CCW_EVENT_CLOSE,
152 	/* last element! */
153 	NR_VFIO_CCW_EVENTS
154 };
155 
156 /*
157  * Action called through jumptable.
158  */
159 typedef void (fsm_func_t)(struct vfio_ccw_private *, enum vfio_ccw_event);
160 extern fsm_func_t *vfio_ccw_jumptable[NR_VFIO_CCW_STATES][NR_VFIO_CCW_EVENTS];
161 
162 static inline void vfio_ccw_fsm_event(struct vfio_ccw_private *private,
163 				      enum vfio_ccw_event event)
164 {
165 	trace_vfio_ccw_fsm_event(private->sch->schid, private->state, event);
166 	vfio_ccw_jumptable[private->state][event](private, event);
167 }
168 
169 extern struct workqueue_struct *vfio_ccw_work_q;
170 
171 
172 /* s390 debug feature, similar to base cio */
173 extern debug_info_t *vfio_ccw_debug_msg_id;
174 extern debug_info_t *vfio_ccw_debug_trace_id;
175 
176 #define VFIO_CCW_TRACE_EVENT(imp, txt) \
177 		debug_text_event(vfio_ccw_debug_trace_id, imp, txt)
178 
179 #define VFIO_CCW_MSG_EVENT(imp, args...) \
180 		debug_sprintf_event(vfio_ccw_debug_msg_id, imp, ##args)
181 
182 static inline void VFIO_CCW_HEX_EVENT(int level, void *data, int length)
183 {
184 	debug_event(vfio_ccw_debug_trace_id, level, data, length);
185 }
186 
187 #endif
188