1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _CSS_H
3 #define _CSS_H
4 
5 #include <linux/mutex.h>
6 #include <linux/wait.h>
7 #include <linux/workqueue.h>
8 #include <linux/device.h>
9 #include <linux/types.h>
10 
11 #include <asm/cio.h>
12 #include <asm/chpid.h>
13 #include <asm/schid.h>
14 
15 #include "cio.h"
16 
17 /*
18  * path grouping stuff
19  */
20 #define SPID_FUNC_SINGLE_PATH	   0x00
21 #define SPID_FUNC_MULTI_PATH	   0x80
22 #define SPID_FUNC_ESTABLISH	   0x00
23 #define SPID_FUNC_RESIGN	   0x40
24 #define SPID_FUNC_DISBAND	   0x20
25 
26 #define SNID_STATE1_RESET	   0
27 #define SNID_STATE1_UNGROUPED	   2
28 #define SNID_STATE1_GROUPED	   3
29 
30 #define SNID_STATE2_NOT_RESVD	   0
31 #define SNID_STATE2_RESVD_ELSE	   2
32 #define SNID_STATE2_RESVD_SELF	   3
33 
34 #define SNID_STATE3_MULTI_PATH	   1
35 #define SNID_STATE3_SINGLE_PATH	   0
36 
37 struct path_state {
38 	__u8  state1 : 2;	/* path state value 1 */
39 	__u8  state2 : 2;	/* path state value 2 */
40 	__u8  state3 : 1;	/* path state value 3 */
41 	__u8  resvd  : 3;	/* reserved */
42 } __attribute__ ((packed));
43 
44 struct extended_cssid {
45 	u8 version;
46 	u8 cssid;
47 } __attribute__ ((packed));
48 
49 struct pgid {
50 	union {
51 		__u8 fc;   	/* SPID function code */
52 		struct path_state ps;	/* SNID path state */
53 	} __attribute__ ((packed)) inf;
54 	union {
55 		__u32 cpu_addr	: 16;	/* CPU address */
56 		struct extended_cssid ext_cssid;
57 	} __attribute__ ((packed)) pgid_high;
58 	__u32 cpu_id	: 24;	/* CPU identification */
59 	__u32 cpu_model : 16;	/* CPU model */
60 	__u32 tod_high;		/* high word TOD clock */
61 } __attribute__ ((packed));
62 
63 struct subchannel;
64 struct chp_link;
65 /**
66  * struct css_driver - device driver for subchannels
67  * @subchannel_type: subchannel type supported by this driver
68  * @drv: embedded device driver structure
69  * @irq: called on interrupts
70  * @chp_event: called for events affecting a channel path
71  * @sch_event: called for events affecting the subchannel
72  * @probe: function called on probe
73  * @remove: function called on remove
74  * @shutdown: called at device shutdown
75  * @prepare: prepare for pm state transition
76  * @complete: undo work done in @prepare
77  * @freeze: callback for freezing during hibernation snapshotting
78  * @thaw: undo work done in @freeze
79  * @restore: callback for restoring after hibernation
80  * @settle: wait for asynchronous work to finish
81  */
82 struct css_driver {
83 	struct css_device_id *subchannel_type;
84 	struct device_driver drv;
85 	void (*irq)(struct subchannel *);
86 	int (*chp_event)(struct subchannel *, struct chp_link *, int);
87 	int (*sch_event)(struct subchannel *, int);
88 	int (*probe)(struct subchannel *);
89 	int (*remove)(struct subchannel *);
90 	void (*shutdown)(struct subchannel *);
91 	int (*prepare) (struct subchannel *);
92 	void (*complete) (struct subchannel *);
93 	int (*freeze)(struct subchannel *);
94 	int (*thaw) (struct subchannel *);
95 	int (*restore)(struct subchannel *);
96 	int (*settle)(void);
97 };
98 
99 #define to_cssdriver(n) container_of(n, struct css_driver, drv)
100 
101 extern int css_driver_register(struct css_driver *);
102 extern void css_driver_unregister(struct css_driver *);
103 
104 extern void css_sch_device_unregister(struct subchannel *);
105 extern int css_register_subchannel(struct subchannel *);
106 extern struct subchannel *css_alloc_subchannel(struct subchannel_id,
107 					       struct schib *schib);
108 extern struct subchannel *get_subchannel_by_schid(struct subchannel_id);
109 extern int css_init_done;
110 extern int max_ssid;
111 int for_each_subchannel_staged(int (*fn_known)(struct subchannel *, void *),
112 			       int (*fn_unknown)(struct subchannel_id,
113 			       void *), void *data);
114 extern int for_each_subchannel(int(*fn)(struct subchannel_id, void *), void *);
115 void css_update_ssd_info(struct subchannel *sch);
116 
117 struct channel_subsystem {
118 	int cssid;
119 	struct channel_path *chps[__MAX_CHPID + 1];
120 	struct device device;
121 	struct pgid global_pgid;
122 	struct mutex mutex;
123 	/* channel measurement related */
124 	int cm_enabled;
125 	void *cub_addr1;
126 	void *cub_addr2;
127 	/* for orphaned ccw devices */
128 	struct subchannel *pseudo_subchannel;
129 };
130 #define to_css(dev) container_of(dev, struct channel_subsystem, device)
131 
132 extern struct channel_subsystem *channel_subsystems[];
133 
134 /* Dummy helper which needs to change once we support more than one css. */
css_by_id(u8 cssid)135 static inline struct channel_subsystem *css_by_id(u8 cssid)
136 {
137 	return channel_subsystems[0];
138 }
139 
140 /* Dummy iterator which needs to change once we support more than one css. */
141 #define for_each_css(css)						\
142 	for ((css) = channel_subsystems[0]; (css); (css) = NULL)
143 
144 /* Helper functions to build lists for the slow path. */
145 void css_schedule_eval(struct subchannel_id schid);
146 void css_schedule_eval_all(void);
147 void css_schedule_eval_all_unreg(unsigned long delay);
148 int css_complete_work(void);
149 
150 int sch_is_pseudo_sch(struct subchannel *);
151 struct schib;
152 int css_sch_is_valid(struct schib *);
153 
154 extern struct workqueue_struct *cio_work_q;
155 void css_wait_for_slow_path(void);
156 void css_sched_sch_todo(struct subchannel *sch, enum sch_todo todo);
157 #endif
158