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 <asm/crw.h>
22 #include <asm/debug.h>
23 
24 #include "css.h"
25 #include "vfio_ccw_cp.h"
26 
27 #define VFIO_CCW_OFFSET_SHIFT   10
28 #define VFIO_CCW_OFFSET_TO_INDEX(off)	(off >> VFIO_CCW_OFFSET_SHIFT)
29 #define VFIO_CCW_INDEX_TO_OFFSET(index)	((u64)(index) << VFIO_CCW_OFFSET_SHIFT)
30 #define VFIO_CCW_OFFSET_MASK	(((u64)(1) << VFIO_CCW_OFFSET_SHIFT) - 1)
31 
32 /* capability chain handling similar to vfio-pci */
33 struct vfio_ccw_private;
34 struct vfio_ccw_region;
35 
36 struct vfio_ccw_regops {
37 	ssize_t	(*read)(struct vfio_ccw_private *private, char __user *buf,
38 			size_t count, loff_t *ppos);
39 	ssize_t	(*write)(struct vfio_ccw_private *private,
40 			 const char __user *buf, size_t count, loff_t *ppos);
41 	void	(*release)(struct vfio_ccw_private *private,
42 			   struct vfio_ccw_region *region);
43 };
44 
45 struct vfio_ccw_region {
46 	u32				type;
47 	u32				subtype;
48 	const struct vfio_ccw_regops	*ops;
49 	void				*data;
50 	size_t				size;
51 	u32				flags;
52 };
53 
54 int vfio_ccw_register_dev_region(struct vfio_ccw_private *private,
55 				 unsigned int subtype,
56 				 const struct vfio_ccw_regops *ops,
57 				 size_t size, u32 flags, void *data);
58 void vfio_ccw_unregister_dev_regions(struct vfio_ccw_private *private);
59 
60 int vfio_ccw_register_async_dev_regions(struct vfio_ccw_private *private);
61 int vfio_ccw_register_schib_dev_regions(struct vfio_ccw_private *private);
62 int vfio_ccw_register_crw_dev_regions(struct vfio_ccw_private *private);
63 
64 struct vfio_ccw_crw {
65 	struct list_head	next;
66 	struct crw		crw;
67 };
68 
69 /**
70  * struct vfio_ccw_private
71  * @vdev: Embedded VFIO device
72  * @sch: pointer to the subchannel
73  * @state: internal state of the device
74  * @completion: synchronization helper of the I/O completion
75  * @avail: available for creating a mediated device
76  * @mdev: pointer to the mediated device
77  * @nb: notifier for vfio events
78  * @io_region: MMIO region to input/output I/O arguments/results
79  * @io_mutex: protect against concurrent update of I/O regions
80  * @region: additional regions for other subchannel operations
81  * @cmd_region: MMIO region for asynchronous I/O commands other than START
82  * @schib_region: MMIO region for SCHIB information
83  * @crw_region: MMIO region for getting channel report words
84  * @num_regions: number of additional regions
85  * @cp: channel program for the current I/O operation
86  * @irb: irb info received from interrupt
87  * @scsw: scsw info
88  * @io_trigger: eventfd ctx for signaling userspace I/O results
89  * @crw_trigger: eventfd ctx for signaling userspace CRW information
90  * @req_trigger: eventfd ctx for signaling userspace to return device
91  * @io_work: work for deferral process of I/O handling
92  * @crw_work: work for deferral process of CRW handling
93  */
94 struct vfio_ccw_private {
95 	struct vfio_device vdev;
96 	struct subchannel	*sch;
97 	int			state;
98 	struct completion	*completion;
99 	atomic_t		avail;
100 	struct mdev_device	*mdev;
101 	struct notifier_block	nb;
102 	struct ccw_io_region	*io_region;
103 	struct mutex		io_mutex;
104 	struct vfio_ccw_region *region;
105 	struct ccw_cmd_region	*cmd_region;
106 	struct ccw_schib_region *schib_region;
107 	struct ccw_crw_region	*crw_region;
108 	int num_regions;
109 
110 	struct channel_program	cp;
111 	struct irb		irb;
112 	union scsw		scsw;
113 	struct list_head	crw;
114 
115 	struct eventfd_ctx	*io_trigger;
116 	struct eventfd_ctx	*crw_trigger;
117 	struct eventfd_ctx	*req_trigger;
118 	struct work_struct	io_work;
119 	struct work_struct	crw_work;
120 } __aligned(8);
121 
122 extern int vfio_ccw_mdev_reg(struct subchannel *sch);
123 extern void vfio_ccw_mdev_unreg(struct subchannel *sch);
124 
125 extern 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 	/* last element! */
151 	NR_VFIO_CCW_EVENTS
152 };
153 
154 /*
155  * Action called through jumptable.
156  */
157 typedef void (fsm_func_t)(struct vfio_ccw_private *, enum vfio_ccw_event);
158 extern fsm_func_t *vfio_ccw_jumptable[NR_VFIO_CCW_STATES][NR_VFIO_CCW_EVENTS];
159 
160 static inline void vfio_ccw_fsm_event(struct vfio_ccw_private *private,
161 				     int event)
162 {
163 	trace_vfio_ccw_fsm_event(private->sch->schid, private->state, event);
164 	vfio_ccw_jumptable[private->state][event](private, event);
165 }
166 
167 extern struct workqueue_struct *vfio_ccw_work_q;
168 
169 
170 /* s390 debug feature, similar to base cio */
171 extern debug_info_t *vfio_ccw_debug_msg_id;
172 extern debug_info_t *vfio_ccw_debug_trace_id;
173 
174 #define VFIO_CCW_TRACE_EVENT(imp, txt) \
175 		debug_text_event(vfio_ccw_debug_trace_id, imp, txt)
176 
177 #define VFIO_CCW_MSG_EVENT(imp, args...) \
178 		debug_sprintf_event(vfio_ccw_debug_msg_id, imp, ##args)
179 
180 static inline void VFIO_CCW_HEX_EVENT(int level, void *data, int length)
181 {
182 	debug_event(vfio_ccw_debug_trace_id, level, data, length);
183 }
184 
185 #endif
186