xref: /linux/drivers/s390/cio/css.h (revision 4b132aacb0768ac1e652cf517097ea6f237214b9)
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 /*
38  * Miscellaneous constants
39  */
40 
41 #define CSS_NUM_CUB_PAGES		2
42 #define CSS_CUES_PER_PAGE		128
43 #define CSS_NUM_ECUB_PAGES		4
44 #define CSS_ECUES_PER_PAGE		64
45 
46 /*
47  * Conditions used to specify which subchannels need evaluation
48  */
49 enum css_eval_cond {
50 	CSS_EVAL_NO_PATH,		/* Subchannels with no operational paths */
51 	CSS_EVAL_NOT_ONLINE	/* sch without an online-device */
52 };
53 
54 struct path_state {
55 	__u8  state1 : 2;	/* path state value 1 */
56 	__u8  state2 : 2;	/* path state value 2 */
57 	__u8  state3 : 1;	/* path state value 3 */
58 	__u8  resvd  : 3;	/* reserved */
59 } __attribute__ ((packed));
60 
61 struct extended_cssid {
62 	u8 version;
63 	u8 cssid;
64 } __attribute__ ((packed));
65 
66 struct pgid {
67 	union {
68 		__u8 fc;   	/* SPID function code */
69 		struct path_state ps;	/* SNID path state */
70 	} __attribute__ ((packed)) inf;
71 	union {
72 		__u32 cpu_addr	: 16;	/* CPU address */
73 		struct extended_cssid ext_cssid;
74 	} __attribute__ ((packed)) pgid_high;
75 	__u32 cpu_id	: 24;	/* CPU identification */
76 	__u32 cpu_model : 16;	/* CPU model */
77 	__u32 tod_high;		/* high word TOD clock */
78 } __attribute__ ((packed));
79 
80 struct subchannel;
81 struct chp_link;
82 /**
83  * struct css_driver - device driver for subchannels
84  * @subchannel_type: subchannel type supported by this driver
85  * @drv: embedded device driver structure
86  * @irq: called on interrupts
87  * @chp_event: called for events affecting a channel path
88  * @sch_event: called for events affecting the subchannel
89  * @probe: function called on probe
90  * @remove: function called on remove
91  * @shutdown: called at device shutdown
92  * @settle: wait for asynchronous work to finish
93  */
94 struct css_driver {
95 	struct css_device_id *subchannel_type;
96 	struct device_driver drv;
97 	void (*irq)(struct subchannel *);
98 	int (*chp_event)(struct subchannel *, struct chp_link *, int);
99 	int (*sch_event)(struct subchannel *, int);
100 	int (*probe)(struct subchannel *);
101 	void (*remove)(struct subchannel *);
102 	void (*shutdown)(struct subchannel *);
103 	int (*settle)(void);
104 };
105 
106 #define to_cssdriver(n) container_of_const(n, struct css_driver, drv)
107 
108 extern int css_driver_register(struct css_driver *);
109 extern void css_driver_unregister(struct css_driver *);
110 
111 extern void css_sch_device_unregister(struct subchannel *);
112 extern int css_register_subchannel(struct subchannel *);
113 extern struct subchannel *css_alloc_subchannel(struct subchannel_id,
114 					       struct schib *schib);
115 extern struct subchannel *get_subchannel_by_schid(struct subchannel_id);
116 extern int css_init_done;
117 extern int max_ssid;
118 int for_each_subchannel_staged(int (*fn_known)(struct subchannel *, void *),
119 			       int (*fn_unknown)(struct subchannel_id,
120 			       void *), void *data);
121 extern int for_each_subchannel(int(*fn)(struct subchannel_id, void *), void *);
122 void css_update_ssd_info(struct subchannel *sch);
123 
124 struct channel_subsystem {
125 	u8 cssid;
126 	u8 iid;
127 	bool id_valid; /* cssid,iid */
128 	struct channel_path *chps[__MAX_CHPID + 1];
129 	struct device device;
130 	struct pgid global_pgid;
131 	struct mutex mutex;
132 	/* channel measurement related */
133 	int cm_enabled;
134 	void *cub[CSS_NUM_CUB_PAGES];
135 	void *ecub[CSS_NUM_ECUB_PAGES];
136 	/* for orphaned ccw devices */
137 	struct subchannel *pseudo_subchannel;
138 };
139 #define to_css(dev) container_of(dev, struct channel_subsystem, device)
140 
141 extern struct channel_subsystem *channel_subsystems[];
142 
143 /* Dummy helper which needs to change once we support more than one css. */
144 static inline struct channel_subsystem *css_by_id(u8 cssid)
145 {
146 	return channel_subsystems[0];
147 }
148 
149 /* Dummy iterator which needs to change once we support more than one css. */
150 #define for_each_css(css)						\
151 	for ((css) = channel_subsystems[0]; (css); (css) = NULL)
152 
153 /* Helper functions to build lists for the slow path. */
154 void css_schedule_eval(struct subchannel_id schid);
155 void css_schedule_eval_all(void);
156 void css_schedule_eval_cond(enum css_eval_cond, unsigned long delay);
157 int css_complete_work(void);
158 
159 int sch_is_pseudo_sch(struct subchannel *);
160 struct schib;
161 int css_sch_is_valid(struct schib *);
162 
163 extern struct workqueue_struct *cio_work_q;
164 void css_wait_for_slow_path(void);
165 void css_sched_sch_todo(struct subchannel *sch, enum sch_todo todo);
166 #endif
167