1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  *  drivers/s390/net/iucv.h
4  *    IUCV base support.
5  *
6  *  S390 version
7  *    Copyright 2000, 2006 IBM Corporation
8  *    Author(s):Alan Altmark (Alan_Altmark@us.ibm.com)
9  *		Xenia Tkatschow (xenia@us.ibm.com)
10  *    Rewritten for af_iucv:
11  *	Martin Schwidefsky <schwidefsky@de.ibm.com>
12  *
13  *
14  * Functionality:
15  * To explore any of the IUCV functions, one must first register their
16  * program using iucv_register(). Once your program has successfully
17  * completed a register, it can exploit the other functions.
18  * For furthur reference on all IUCV functionality, refer to the
19  * CP Programming Services book, also available on the web thru
20  * www.vm.ibm.com/pubs, manual # SC24-6084
21  *
22  * Definition of Return Codes
23  * - All positive return codes including zero are reflected back
24  *   from CP. The definition of each return code can be found in
25  *   CP Programming Services book.
26  * - Return Code of:
27  *   -EINVAL: Invalid value
28  *   -ENOMEM: storage allocation failed
29  */
30 
31 #include <linux/types.h>
32 #include <linux/slab.h>
33 #include <asm/debug.h>
34 
35 /*
36  * IUCV option flags usable by device drivers:
37  *
38  * IUCV_IPRMDATA  Indicates that your program can handle a message in the
39  *		  parameter list / a message is sent in the parameter list.
40  *		  Used for iucv_path_accept, iucv_path_connect,
41  *		  iucv_message_reply, iucv_message_send, iucv_message_send2way.
42  * IUCV_IPQUSCE	  Indicates that you do not want to receive messages on this
43  *		  path until an iucv_path_resume is issued.
44  *		  Used for iucv_path_accept, iucv_path_connect.
45  * IUCV_IPBUFLST  Indicates that an address list is used for the message data.
46  *		  Used for iucv_message_receive, iucv_message_send,
47  *		  iucv_message_send2way.
48  * IUCV_IPPRTY	  Specifies that you want to send priority messages.
49  *		  Used for iucv_path_accept, iucv_path_connect,
50  *		  iucv_message_reply, iucv_message_send, iucv_message_send2way.
51  * IUCV_IPSYNC	  Indicates a synchronous send request.
52  *		  Used for iucv_message_send, iucv_message_send2way.
53  * IUCV_IPANSLST  Indicates that an address list is used for the reply data.
54  *		  Used for iucv_message_reply, iucv_message_send2way.
55  * IUCV_IPLOCAL	  Specifies that the communication partner has to be on the
56  *		  local system. If local is specified no target class can be
57  *		  specified.
58  *		  Used for iucv_path_connect.
59  *
60  * All flags are defined in the input field IPFLAGS1 of each function
61  * and can be found in CP Programming Services.
62  */
63 #define IUCV_IPRMDATA	0x80
64 #define IUCV_IPQUSCE	0x40
65 #define IUCV_IPBUFLST	0x40
66 #define IUCV_IPPRTY	0x20
67 #define IUCV_IPANSLST	0x08
68 #define IUCV_IPSYNC	0x04
69 #define IUCV_IPLOCAL	0x01
70 
71 /*
72  * iucv_array : Defines buffer array.
73  * Inside the array may be 31- bit addresses and 31-bit lengths.
74  * Use a pointer to an iucv_array as the buffer, reply or answer
75  * parameter on iucv_message_send, iucv_message_send2way, iucv_message_receive
76  * and iucv_message_reply if IUCV_IPBUFLST or IUCV_IPANSLST are used.
77  */
78 struct iucv_array {
79 	u32 address;
80 	u32 length;
81 } __attribute__ ((aligned (8)));
82 
83 extern struct bus_type iucv_bus;
84 extern struct device *iucv_root;
85 
86 /*
87  * struct iucv_path
88  * pathid: 16 bit path identification
89  * msglim: 16 bit message limit
90  * flags: properties of the path: IPRMDATA, IPQUSCE, IPPRTY
91  * handler:  address of iucv handler structure
92  * private: private information of the handler associated with the path
93  * list: list_head for the iucv_handler path list.
94  */
95 struct iucv_path {
96 	u16 pathid;
97 	u16 msglim;
98 	u8  flags;
99 	void *private;
100 	struct iucv_handler *handler;
101 	struct list_head list;
102 };
103 
104 /*
105  * struct iucv_message
106  * id: 32 bit message id
107  * audit: 32 bit error information of purged or replied messages
108  * class: 32 bit target class of a message (source class for replies)
109  * tag: 32 bit tag to be associated with the message
110  * length: 32 bit length of the message / reply
111  * reply_size: 32 bit maximum allowed length of the reply
112  * rmmsg: 8 byte inline message
113  * flags: message properties (IUCV_IPPRTY)
114  */
115 struct iucv_message {
116 	u32 id;
117 	u32 audit;
118 	u32 class;
119 	u32 tag;
120 	u32 length;
121 	u32 reply_size;
122 	u8  rmmsg[8];
123 	u8  flags;
124 } __packed;
125 
126 /*
127  * struct iucv_handler
128  *
129  * A vector of functions that handle IUCV interrupts. Each functions gets
130  * a parameter area as defined by the CP Programming Services and private
131  * pointer that is provided by the user of the interface.
132  */
133 struct iucv_handler {
134 	 /*
135 	  * The path_pending function is called after an iucv interrupt
136 	  * type 0x01 has been received. The base code allocates a path
137 	  * structure and "asks" the handler if this path belongs to the
138 	  * handler. To accept the path the path_pending function needs
139 	  * to call iucv_path_accept and return 0. If the callback returns
140 	  * a value != 0 the iucv base code will continue with the next
141 	  * handler. The order in which the path_pending functions are
142 	  * called is the order of the registration of the iucv handlers
143 	  * to the base code.
144 	  */
145 	int  (*path_pending)(struct iucv_path *, u8 *ipvmid, u8 *ipuser);
146 	/*
147 	 * The path_complete function is called after an iucv interrupt
148 	 * type 0x02 has been received for a path that has been established
149 	 * for this handler with iucv_path_connect and got accepted by the
150 	 * peer with iucv_path_accept.
151 	 */
152 	void (*path_complete)(struct iucv_path *, u8 *ipuser);
153 	 /*
154 	  * The path_severed function is called after an iucv interrupt
155 	  * type 0x03 has been received. The communication peer shutdown
156 	  * his end of the communication path. The path still exists and
157 	  * remaining messages can be received until a iucv_path_sever
158 	  * shuts down the other end of the path as well.
159 	  */
160 	void (*path_severed)(struct iucv_path *, u8 *ipuser);
161 	/*
162 	 * The path_quiesced function is called after an icuv interrupt
163 	 * type 0x04 has been received. The communication peer has quiesced
164 	 * the path. Delivery of messages is stopped until iucv_path_resume
165 	 * has been called.
166 	 */
167 	void (*path_quiesced)(struct iucv_path *, u8 *ipuser);
168 	/*
169 	 * The path_resumed function is called after an icuv interrupt
170 	 * type 0x05 has been received. The communication peer has resumed
171 	 * the path.
172 	 */
173 	void (*path_resumed)(struct iucv_path *, u8 *ipuser);
174 	/*
175 	 * The message_pending function is called after an icuv interrupt
176 	 * type 0x06 or type 0x07 has been received. A new message is
177 	 * available and can be received with iucv_message_receive.
178 	 */
179 	void (*message_pending)(struct iucv_path *, struct iucv_message *);
180 	/*
181 	 * The message_complete function is called after an icuv interrupt
182 	 * type 0x08 or type 0x09 has been received. A message send with
183 	 * iucv_message_send2way has been replied to. The reply can be
184 	 * received with iucv_message_receive.
185 	 */
186 	void (*message_complete)(struct iucv_path *, struct iucv_message *);
187 
188 	struct list_head list;
189 	struct list_head paths;
190 };
191 
192 /**
193  * iucv_register:
194  * @handler: address of iucv handler structure
195  * @smp: != 0 indicates that the handler can deal with out of order messages
196  *
197  * Registers a driver with IUCV.
198  *
199  * Returns 0 on success, -ENOMEM if the memory allocation for the pathid
200  * table failed, or -EIO if IUCV_DECLARE_BUFFER failed on all cpus.
201  */
202 int iucv_register(struct iucv_handler *handler, int smp);
203 
204 /**
205  * iucv_unregister
206  * @handler:  address of iucv handler structure
207  * @smp: != 0 indicates that the handler can deal with out of order messages
208  *
209  * Unregister driver from IUCV.
210  */
211 void iucv_unregister(struct iucv_handler *handle, int smp);
212 
213 /**
214  * iucv_path_alloc
215  * @msglim: initial message limit
216  * @flags: initial flags
217  * @gfp: kmalloc allocation flag
218  *
219  * Allocate a new path structure for use with iucv_connect.
220  *
221  * Returns NULL if the memory allocation failed or a pointer to the
222  * path structure.
223  */
iucv_path_alloc(u16 msglim,u8 flags,gfp_t gfp)224 static inline struct iucv_path *iucv_path_alloc(u16 msglim, u8 flags, gfp_t gfp)
225 {
226 	struct iucv_path *path;
227 
228 	path = kzalloc(sizeof(struct iucv_path), gfp);
229 	if (path) {
230 		path->msglim = msglim;
231 		path->flags = flags;
232 	}
233 	return path;
234 }
235 
236 /**
237  * iucv_path_free
238  * @path: address of iucv path structure
239  *
240  * Frees a path structure.
241  */
iucv_path_free(struct iucv_path * path)242 static inline void iucv_path_free(struct iucv_path *path)
243 {
244 	kfree(path);
245 }
246 
247 /**
248  * iucv_path_accept
249  * @path: address of iucv path structure
250  * @handler: address of iucv handler structure
251  * @userdata: 16 bytes of data reflected to the communication partner
252  * @private: private data passed to interrupt handlers for this path
253  *
254  * This function is issued after the user received a connection pending
255  * external interrupt and now wishes to complete the IUCV communication path.
256  *
257  * Returns the result of the CP IUCV call.
258  */
259 int iucv_path_accept(struct iucv_path *path, struct iucv_handler *handler,
260 		     u8 *userdata, void *private);
261 
262 /**
263  * iucv_path_connect
264  * @path: address of iucv path structure
265  * @handler: address of iucv handler structure
266  * @userid: 8-byte user identification
267  * @system: 8-byte target system identification
268  * @userdata: 16 bytes of data reflected to the communication partner
269  * @private: private data passed to interrupt handlers for this path
270  *
271  * This function establishes an IUCV path. Although the connect may complete
272  * successfully, you are not able to use the path until you receive an IUCV
273  * Connection Complete external interrupt.
274  *
275  * Returns the result of the CP IUCV call.
276  */
277 int iucv_path_connect(struct iucv_path *path, struct iucv_handler *handler,
278 		      u8 *userid, u8 *system, u8 *userdata,
279 		      void *private);
280 
281 /**
282  * iucv_path_quiesce:
283  * @path: address of iucv path structure
284  * @userdata: 16 bytes of data reflected to the communication partner
285  *
286  * This function temporarily suspends incoming messages on an IUCV path.
287  * You can later reactivate the path by invoking the iucv_resume function.
288  *
289  * Returns the result from the CP IUCV call.
290  */
291 int iucv_path_quiesce(struct iucv_path *path, u8 *userdata);
292 
293 /**
294  * iucv_path_resume:
295  * @path: address of iucv path structure
296  * @userdata: 16 bytes of data reflected to the communication partner
297  *
298  * This function resumes incoming messages on an IUCV path that has
299  * been stopped with iucv_path_quiesce.
300  *
301  * Returns the result from the CP IUCV call.
302  */
303 int iucv_path_resume(struct iucv_path *path, u8 *userdata);
304 
305 /**
306  * iucv_path_sever
307  * @path: address of iucv path structure
308  * @userdata: 16 bytes of data reflected to the communication partner
309  *
310  * This function terminates an IUCV path.
311  *
312  * Returns the result from the CP IUCV call.
313  */
314 int iucv_path_sever(struct iucv_path *path, u8 *userdata);
315 
316 /**
317  * iucv_message_purge
318  * @path: address of iucv path structure
319  * @msg: address of iucv msg structure
320  * @srccls: source class of message
321  *
322  * Cancels a message you have sent.
323  *
324  * Returns the result from the CP IUCV call.
325  */
326 int iucv_message_purge(struct iucv_path *path, struct iucv_message *msg,
327 		       u32 srccls);
328 
329 /**
330  * iucv_message_receive
331  * @path: address of iucv path structure
332  * @msg: address of iucv msg structure
333  * @flags: flags that affect how the message is received (IUCV_IPBUFLST)
334  * @buffer: address of data buffer or address of struct iucv_array
335  * @size: length of data buffer
336  * @residual:
337  *
338  * This function receives messages that are being sent to you over
339  * established paths. This function will deal with RMDATA messages
340  * embedded in struct iucv_message as well.
341  *
342  * Locking:	local_bh_enable/local_bh_disable
343  *
344  * Returns the result from the CP IUCV call.
345  */
346 int iucv_message_receive(struct iucv_path *path, struct iucv_message *msg,
347 			 u8 flags, void *buffer, size_t size, size_t *residual);
348 
349 /**
350  * __iucv_message_receive
351  * @path: address of iucv path structure
352  * @msg: address of iucv msg structure
353  * @flags: flags that affect how the message is received (IUCV_IPBUFLST)
354  * @buffer: address of data buffer or address of struct iucv_array
355  * @size: length of data buffer
356  * @residual:
357  *
358  * This function receives messages that are being sent to you over
359  * established paths. This function will deal with RMDATA messages
360  * embedded in struct iucv_message as well.
361  *
362  * Locking:	no locking.
363  *
364  * Returns the result from the CP IUCV call.
365  */
366 int __iucv_message_receive(struct iucv_path *path, struct iucv_message *msg,
367 			   u8 flags, void *buffer, size_t size,
368 			   size_t *residual);
369 
370 /**
371  * iucv_message_reject
372  * @path: address of iucv path structure
373  * @msg: address of iucv msg structure
374  *
375  * The reject function refuses a specified message. Between the time you
376  * are notified of a message and the time that you complete the message,
377  * the message may be rejected.
378  *
379  * Returns the result from the CP IUCV call.
380  */
381 int iucv_message_reject(struct iucv_path *path, struct iucv_message *msg);
382 
383 /**
384  * iucv_message_reply
385  * @path: address of iucv path structure
386  * @msg: address of iucv msg structure
387  * @flags: how the reply is sent (IUCV_IPRMDATA, IUCV_IPPRTY, IUCV_IPBUFLST)
388  * @reply: address of data buffer or address of struct iucv_array
389  * @size: length of reply data buffer
390  *
391  * This function responds to the two-way messages that you receive. You
392  * must identify completely the message to which you wish to reply. ie,
393  * pathid, msgid, and trgcls. Prmmsg signifies the data is moved into
394  * the parameter list.
395  *
396  * Returns the result from the CP IUCV call.
397  */
398 int iucv_message_reply(struct iucv_path *path, struct iucv_message *msg,
399 		       u8 flags, void *reply, size_t size);
400 
401 /**
402  * iucv_message_send
403  * @path: address of iucv path structure
404  * @msg: address of iucv msg structure
405  * @flags: how the message is sent (IUCV_IPRMDATA, IUCV_IPPRTY, IUCV_IPBUFLST)
406  * @srccls: source class of message
407  * @buffer: address of data buffer or address of struct iucv_array
408  * @size: length of send buffer
409  *
410  * This function transmits data to another application. Data to be
411  * transmitted is in a buffer and this is a one-way message and the
412  * receiver will not reply to the message.
413  *
414  * Locking:	local_bh_enable/local_bh_disable
415  *
416  * Returns the result from the CP IUCV call.
417  */
418 int iucv_message_send(struct iucv_path *path, struct iucv_message *msg,
419 		      u8 flags, u32 srccls, void *buffer, size_t size);
420 
421 /**
422  * __iucv_message_send
423  * @path: address of iucv path structure
424  * @msg: address of iucv msg structure
425  * @flags: how the message is sent (IUCV_IPRMDATA, IUCV_IPPRTY, IUCV_IPBUFLST)
426  * @srccls: source class of message
427  * @buffer: address of data buffer or address of struct iucv_array
428  * @size: length of send buffer
429  *
430  * This function transmits data to another application. Data to be
431  * transmitted is in a buffer and this is a one-way message and the
432  * receiver will not reply to the message.
433  *
434  * Locking:	no locking.
435  *
436  * Returns the result from the CP IUCV call.
437  */
438 int __iucv_message_send(struct iucv_path *path, struct iucv_message *msg,
439 			u8 flags, u32 srccls, void *buffer, size_t size);
440 
441 /**
442  * iucv_message_send2way
443  * @path: address of iucv path structure
444  * @msg: address of iucv msg structure
445  * @flags: how the message is sent and the reply is received
446  *	   (IUCV_IPRMDATA, IUCV_IPBUFLST, IUCV_IPPRTY, IUCV_ANSLST)
447  * @srccls: source class of message
448  * @buffer: address of data buffer or address of struct iucv_array
449  * @size: length of send buffer
450  * @ansbuf: address of answer buffer or address of struct iucv_array
451  * @asize: size of reply buffer
452  *
453  * This function transmits data to another application. Data to be
454  * transmitted is in a buffer. The receiver of the send is expected to
455  * reply to the message and a buffer is provided into which IUCV moves
456  * the reply to this message.
457  *
458  * Returns the result from the CP IUCV call.
459  */
460 int iucv_message_send2way(struct iucv_path *path, struct iucv_message *msg,
461 			  u8 flags, u32 srccls, void *buffer, size_t size,
462 			  void *answer, size_t asize, size_t *residual);
463 
464 struct iucv_interface {
465 	int (*message_receive)(struct iucv_path *path, struct iucv_message *msg,
466 		u8 flags, void *buffer, size_t size, size_t *residual);
467 	int (*__message_receive)(struct iucv_path *path,
468 		struct iucv_message *msg, u8 flags, void *buffer, size_t size,
469 		size_t *residual);
470 	int (*message_reply)(struct iucv_path *path, struct iucv_message *msg,
471 		u8 flags, void *reply, size_t size);
472 	int (*message_reject)(struct iucv_path *path, struct iucv_message *msg);
473 	int (*message_send)(struct iucv_path *path, struct iucv_message *msg,
474 		u8 flags, u32 srccls, void *buffer, size_t size);
475 	int (*__message_send)(struct iucv_path *path, struct iucv_message *msg,
476 		u8 flags, u32 srccls, void *buffer, size_t size);
477 	int (*message_send2way)(struct iucv_path *path,
478 		struct iucv_message *msg, u8 flags, u32 srccls, void *buffer,
479 		size_t size, void *answer, size_t asize, size_t *residual);
480 	int (*message_purge)(struct iucv_path *path, struct iucv_message *msg,
481 		u32 srccls);
482 	int (*path_accept)(struct iucv_path *path, struct iucv_handler *handler,
483 		u8 userdata[16], void *private);
484 	int (*path_connect)(struct iucv_path *path,
485 		struct iucv_handler *handler,
486 		u8 userid[8], u8 system[8], u8 userdata[16], void *private);
487 	int (*path_quiesce)(struct iucv_path *path, u8 userdata[16]);
488 	int (*path_resume)(struct iucv_path *path, u8 userdata[16]);
489 	int (*path_sever)(struct iucv_path *path, u8 userdata[16]);
490 	int (*iucv_register)(struct iucv_handler *handler, int smp);
491 	void (*iucv_unregister)(struct iucv_handler *handler, int smp);
492 	struct bus_type *bus;
493 	struct device *root;
494 };
495 
496 extern struct iucv_interface iucv_if;
497