css.h

  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 */
 49enum 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
 54struct 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
 61struct extended_cssid {
 62	u8 version;
 63	u8 cssid;
 64} __attribute__ ((packed));
 65
 66struct 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
 80struct subchannel;
 81struct 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 */
 94struct 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
108extern int css_driver_register(struct css_driver *);
109extern void css_driver_unregister(struct css_driver *);
110
111extern void css_sch_device_unregister(struct subchannel *);
112extern int css_register_subchannel(struct subchannel *);
113extern struct subchannel *css_alloc_subchannel(struct subchannel_id,
114					       struct schib *schib);
115extern struct subchannel *get_subchannel_by_schid(struct subchannel_id);
116extern int css_init_done;
117extern int max_ssid;
118int for_each_subchannel_staged(int (*fn_known)(struct subchannel *, void *),
119			       int (*fn_unknown)(struct subchannel_id,
120			       void *), void *data);
121extern int for_each_subchannel(int(*fn)(struct subchannel_id, void *), void *);
122void css_update_ssd_info(struct subchannel *sch);
123
124struct 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
141extern struct channel_subsystem *channel_subsystems[];
142
143/* Dummy helper which needs to change once we support more than one css. */
144static 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. */
154void css_schedule_eval(struct subchannel_id schid);
155void css_schedule_eval_all(void);
156void css_schedule_eval_cond(enum css_eval_cond, unsigned long delay);
157int css_complete_work(void);
158
159int sch_is_pseudo_sch(struct subchannel *);
160struct schib;
161int css_sch_is_valid(struct schib *);
162
163extern struct workqueue_struct *cio_work_q;
164void css_wait_for_slow_path(void);
165void css_sched_sch_todo(struct subchannel *sch, enum sch_todo todo);
166#endif