1 /* Copyright (C) 2010 - 2013 UNISYS CORPORATION
2 * All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or (at
7 * your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
12 * NON INFRINGEMENT. See the GNU General Public License for more
13 * details.
14 */
15
16 #ifndef __CHANNEL_H__
17 #define __CHANNEL_H__
18
19 #include <linux/types.h>
20 #include <linux/io.h>
21 #include <linux/uuid.h>
22
23 /*
24 * Whenever this file is changed a corresponding change must be made in
25 * the Console/ServicePart/visordiag_early/supervisor_channel.h file
26 * which is needed for Linux kernel compiles. These two files must be
27 * in sync.
28 */
29
30 /* define the following to prevent include nesting in kernel header
31 * files of similar abbreviated content
32 */
33 #define __SUPERVISOR_CHANNEL_H__
34
35 #define SIGNATURE_16(A, B) ((A) | (B<<8))
36 #define SIGNATURE_32(A, B, C, D) \
37 (SIGNATURE_16(A, B) | (SIGNATURE_16(C, D) << 16))
38 #define SIGNATURE_64(A, B, C, D, E, F, G, H) \
39 (SIGNATURE_32(A, B, C, D) | ((u64)(SIGNATURE_32(E, F, G, H)) << 32))
40
41 #ifndef lengthof
42 #define lengthof(TYPE, MEMBER) (sizeof(((TYPE *)0)->MEMBER))
43 #endif
44 #ifndef COVERQ
45 #define COVERQ(v, d) (((v)+(d)-1) / (d))
46 #endif
47 #ifndef COVER
48 #define COVER(v, d) ((d)*COVERQ(v, d))
49 #endif
50
51 #define ULTRA_CHANNEL_PROTOCOL_SIGNATURE SIGNATURE_32('E', 'C', 'N', 'L')
52
53 enum channel_serverstate {
54 CHANNELSRV_UNINITIALIZED = 0, /* channel is in an undefined state */
55 CHANNELSRV_READY = 1 /* channel has been initialized by server */
56 };
57
58 enum channel_clientstate {
59 CHANNELCLI_DETACHED = 0,
60 CHANNELCLI_DISABLED = 1, /* client can see channel but is NOT
61 * allowed to use it unless given TBD
62 * explicit request (should actually be
63 * < DETACHED) */
64 CHANNELCLI_ATTACHING = 2, /* legacy EFI client request
65 * for EFI server to attach */
66 CHANNELCLI_ATTACHED = 3, /* idle, but client may want
67 * to use channel any time */
68 CHANNELCLI_BUSY = 4, /* client either wants to use or is
69 * using channel */
70 CHANNELCLI_OWNED = 5 /* "no worries" state - client can
71 * access channel anytime */
72 };
73
74 static inline const u8 *
ULTRA_CHANNELCLI_STRING(u32 v)75 ULTRA_CHANNELCLI_STRING(u32 v)
76 {
77 switch (v) {
78 case CHANNELCLI_DETACHED:
79 return (const u8 *)("DETACHED");
80 case CHANNELCLI_DISABLED:
81 return (const u8 *)("DISABLED");
82 case CHANNELCLI_ATTACHING:
83 return (const u8 *)("ATTACHING");
84 case CHANNELCLI_ATTACHED:
85 return (const u8 *)("ATTACHED");
86 case CHANNELCLI_BUSY:
87 return (const u8 *)("BUSY");
88 case CHANNELCLI_OWNED:
89 return (const u8 *)("OWNED");
90 default:
91 break;
92 }
93 return (const u8 *)("?");
94 }
95
96 #define SPAR_CHANNEL_SERVER_READY(ch) \
97 (readl(&(ch)->srv_state) == CHANNELSRV_READY)
98
99 #define ULTRA_VALID_CHANNELCLI_TRANSITION(o, n) \
100 (((((o) == CHANNELCLI_DETACHED) && ((n) == CHANNELCLI_DISABLED)) || \
101 (((o) == CHANNELCLI_ATTACHING) && ((n) == CHANNELCLI_DISABLED)) || \
102 (((o) == CHANNELCLI_ATTACHED) && ((n) == CHANNELCLI_DISABLED)) || \
103 (((o) == CHANNELCLI_ATTACHING) && ((n) == CHANNELCLI_DETACHED)) || \
104 (((o) == CHANNELCLI_ATTACHED) && ((n) == CHANNELCLI_DETACHED)) || \
105 (((o) == CHANNELCLI_DETACHED) && ((n) == CHANNELCLI_ATTACHING)) || \
106 (((o) == CHANNELCLI_ATTACHING) && ((n) == CHANNELCLI_ATTACHED)) || \
107 (((o) == CHANNELCLI_DETACHED) && ((n) == CHANNELCLI_ATTACHED)) || \
108 (((o) == CHANNELCLI_BUSY) && ((n) == CHANNELCLI_ATTACHED)) || \
109 (((o) == CHANNELCLI_ATTACHED) && ((n) == CHANNELCLI_BUSY)) || \
110 (((o) == CHANNELCLI_DETACHED) && ((n) == CHANNELCLI_OWNED)) || \
111 (((o) == CHANNELCLI_DISABLED) && ((n) == CHANNELCLI_OWNED)) || \
112 (((o) == CHANNELCLI_ATTACHING) && ((n) == CHANNELCLI_OWNED)) || \
113 (((o) == CHANNELCLI_ATTACHED) && ((n) == CHANNELCLI_OWNED)) || \
114 (((o) == CHANNELCLI_BUSY) && ((n) == CHANNELCLI_OWNED)) || (0)) \
115 ? (1) : (0))
116
117 #define SPAR_CHANNEL_CLIENT_CHK_TRANSITION(old, new, id, log, \
118 file, line) \
119 do { \
120 if (!ULTRA_VALID_CHANNELCLI_TRANSITION(old, new)) \
121 pr_info("%s Channel StateTransition INVALID! (%s) %s(%d)-->%s(%d) @%s:%d\n", \
122 id, "CliState<x>", \
123 ULTRA_CHANNELCLI_STRING(old), \
124 old, \
125 ULTRA_CHANNELCLI_STRING(new), \
126 new, \
127 pathname_last_n_nodes((u8 *)file, 4), \
128 line); \
129 } while (0)
130
131 #define SPAR_CHANNEL_CLIENT_TRANSITION(ch, id, newstate, log) \
132 do { \
133 SPAR_CHANNEL_CLIENT_CHK_TRANSITION( \
134 readl(&(((struct channel_header __iomem *)\
135 (ch))->cli_state_os)), \
136 newstate, id, log, __FILE__, __LINE__); \
137 pr_info("%s Channel StateTransition (%s) %s(%d)-->%s(%d) @%s:%d\n", \
138 id, "CliStateOS", \
139 ULTRA_CHANNELCLI_STRING( \
140 readl(&((struct channel_header __iomem *)\
141 (ch))->cli_state_os)), \
142 readl(&((struct channel_header __iomem *)\
143 (ch))->cli_state_os), \
144 ULTRA_CHANNELCLI_STRING(newstate), \
145 newstate, \
146 pathname_last_n_nodes(__FILE__, 4), __LINE__); \
147 writel(newstate, &((struct channel_header __iomem *)\
148 (ch))->cli_state_os); \
149 mb(); /* required for channel synch */ \
150 } while (0)
151
152 /* Values for ULTRA_CHANNEL_PROTOCOL.CliErrorBoot: */
153 /* throttling invalid boot channel statetransition error due to client
154 * disabled */
155 #define ULTRA_CLIERRORBOOT_THROTTLEMSG_DISABLED 0x01
156
157 /* throttling invalid boot channel statetransition error due to client
158 * not attached */
159 #define ULTRA_CLIERRORBOOT_THROTTLEMSG_NOTATTACHED 0x02
160
161 /* throttling invalid boot channel statetransition error due to busy channel */
162 #define ULTRA_CLIERRORBOOT_THROTTLEMSG_BUSY 0x04
163
164 /* Values for ULTRA_CHANNEL_PROTOCOL.CliErrorOS: */
165 /* throttling invalid guest OS channel statetransition error due to
166 * client disabled */
167 #define ULTRA_CLIERROROS_THROTTLEMSG_DISABLED 0x01
168
169 /* throttling invalid guest OS channel statetransition error due to
170 * client not attached */
171 #define ULTRA_CLIERROROS_THROTTLEMSG_NOTATTACHED 0x02
172
173 /* throttling invalid guest OS channel statetransition error due to
174 * busy channel */
175 #define ULTRA_CLIERROROS_THROTTLEMSG_BUSY 0x04
176
177 /* Values for ULTRA_CHANNEL_PROTOCOL.Features: This define exists so
178 * that windows guest can look at the FeatureFlags in the io channel,
179 * and configure the windows driver to use interrupts or not based on
180 * this setting. This flag is set in uislib after the
181 * ULTRA_VHBA_init_channel is called. All feature bits for all
182 * channels should be defined here. The io channel feature bits are
183 * defined right here */
184 #define ULTRA_IO_DRIVER_ENABLES_INTS (0x1ULL << 1)
185 #define ULTRA_IO_CHANNEL_IS_POLLING (0x1ULL << 3)
186 #define ULTRA_IO_IOVM_IS_OK_WITH_DRIVER_DISABLING_INTS (0x1ULL << 4)
187 #define ULTRA_IO_DRIVER_DISABLES_INTS (0x1ULL << 5)
188 #define ULTRA_IO_DRIVER_SUPPORTS_ENHANCED_RCVBUF_CHECKING (0x1ULL << 6)
189
190 #pragma pack(push, 1) /* both GCC and VC now allow this pragma */
191 /* Common Channel Header */
192 struct channel_header {
193 u64 signature; /* Signature */
194 u32 legacy_state; /* DEPRECATED - being replaced by */
195 /* / SrvState, CliStateBoot, and CliStateOS below */
196 u32 header_size; /* sizeof(struct channel_header) */
197 u64 size; /* Total size of this channel in bytes */
198 u64 features; /* Flags to modify behavior */
199 uuid_le chtype; /* Channel type: data, bus, control, etc. */
200 u64 partition_handle; /* ID of guest partition */
201 u64 handle; /* Device number of this channel in client */
202 u64 ch_space_offset; /* Offset in bytes to channel specific area */
203 u32 version_id; /* struct channel_header Version ID */
204 u32 partition_index; /* Index of guest partition */
205 uuid_le zone_uuid; /* Guid of Channel's zone */
206 u32 cli_str_offset; /* offset from channel header to
207 * nul-terminated ClientString (0 if
208 * ClientString not present) */
209 u32 cli_state_boot; /* CHANNEL_CLIENTSTATE of pre-boot
210 * EFI client of this channel */
211 u32 cmd_state_cli; /* CHANNEL_COMMANDSTATE (overloaded in
212 * Windows drivers, see ServerStateUp,
213 * ServerStateDown, etc) */
214 u32 cli_state_os; /* CHANNEL_CLIENTSTATE of Guest OS
215 * client of this channel */
216 u32 ch_characteristic; /* CHANNEL_CHARACTERISTIC_<xxx> */
217 u32 cmd_state_srv; /* CHANNEL_COMMANDSTATE (overloaded in
218 * Windows drivers, see ServerStateUp,
219 * ServerStateDown, etc) */
220 u32 srv_state; /* CHANNEL_SERVERSTATE */
221 u8 cli_error_boot; /* bits to indicate err states for
222 * boot clients, so err messages can
223 * be throttled */
224 u8 cli_error_os; /* bits to indicate err states for OS
225 * clients, so err messages can be
226 * throttled */
227 u8 filler[1]; /* Pad out to 128 byte cacheline */
228 /* Please add all new single-byte values below here */
229 u8 recover_channel;
230 };
231
232 #define ULTRA_CHANNEL_ENABLE_INTS (0x1ULL << 0)
233
234 /* Subheader for the Signal Type variation of the Common Channel */
235 struct signal_queue_header {
236 /* 1st cache line */
237 u32 version; /* SIGNAL_QUEUE_HEADER Version ID */
238 u32 chtype; /* Queue type: storage, network */
239 u64 size; /* Total size of this queue in bytes */
240 u64 sig_base_offset; /* Offset to signal queue area */
241 u64 features; /* Flags to modify behavior */
242 u64 num_sent; /* Total # of signals placed in this queue */
243 u64 num_overflows; /* Total # of inserts failed due to
244 * full queue */
245 u32 signal_size; /* Total size of a signal for this queue */
246 u32 max_slots; /* Max # of slots in queue, 1 slot is
247 * always empty */
248 u32 max_signals; /* Max # of signals in queue
249 * (MaxSignalSlots-1) */
250 u32 head; /* Queue head signal # */
251 /* 2nd cache line */
252 u64 num_received; /* Total # of signals removed from this queue */
253 u32 tail; /* Queue tail signal # (on separate
254 * cache line) */
255 u32 reserved1; /* Reserved field */
256 u64 reserved2; /* Reserved field */
257 u64 client_queue;
258 u64 num_irq_received; /* Total # of Interrupts received. This
259 * is incremented by the ISR in the
260 * guest windows driver */
261 u64 num_empty; /* Number of times that visor_signal_remove
262 * is called and returned Empty
263 * Status. */
264 u32 errorflags; /* Error bits set during SignalReinit
265 * to denote trouble with client's
266 * fields */
267 u8 filler[12]; /* Pad out to 64 byte cacheline */
268 };
269
270 #pragma pack(pop)
271
272 #define spar_signal_init(chan, QHDRFLD, QDATAFLD, QDATATYPE, ver, typ) \
273 do { \
274 memset(&chan->QHDRFLD, 0, sizeof(chan->QHDRFLD)); \
275 chan->QHDRFLD.version = ver; \
276 chan->QHDRFLD.chtype = typ; \
277 chan->QHDRFLD.size = sizeof(chan->QDATAFLD); \
278 chan->QHDRFLD.signal_size = sizeof(QDATATYPE); \
279 chan->QHDRFLD.sig_base_offset = (u64)(chan->QDATAFLD)- \
280 (u64)(&chan->QHDRFLD); \
281 chan->QHDRFLD.max_slots = \
282 sizeof(chan->QDATAFLD)/sizeof(QDATATYPE); \
283 chan->QHDRFLD.max_signals = chan->QHDRFLD.max_slots-1; \
284 } while (0)
285
286 /* Generic function useful for validating any type of channel when it is
287 * received by the client that will be accessing the channel.
288 * Note that <logCtx> is only needed for callers in the EFI environment, and
289 * is used to pass the EFI_DIAG_CAPTURE_PROTOCOL needed to log messages.
290 */
291 static inline int
spar_check_channel_client(void __iomem * ch,uuid_le expected_uuid,char * chname,u64 expected_min_bytes,u32 expected_version,u64 expected_signature)292 spar_check_channel_client(void __iomem *ch,
293 uuid_le expected_uuid,
294 char *chname,
295 u64 expected_min_bytes,
296 u32 expected_version,
297 u64 expected_signature)
298 {
299 if (uuid_le_cmp(expected_uuid, NULL_UUID_LE) != 0) {
300 uuid_le guid;
301
302 memcpy_fromio(&guid,
303 &((struct channel_header __iomem *)(ch))->chtype,
304 sizeof(guid));
305 /* caller wants us to verify type GUID */
306 if (uuid_le_cmp(guid, expected_uuid) != 0) {
307 pr_err("Channel mismatch on channel=%s(%pUL) field=type expected=%pUL actual=%pUL\n",
308 chname, &expected_uuid,
309 &expected_uuid, &guid);
310 return 0;
311 }
312 }
313 if (expected_min_bytes > 0) { /* caller wants us to verify
314 * channel size */
315 unsigned long long bytes =
316 readq(&((struct channel_header __iomem *)
317 (ch))->size);
318 if (bytes < expected_min_bytes) {
319 pr_err("Channel mismatch on channel=%s(%pUL) field=size expected=0x%-8.8Lx actual=0x%-8.8Lx\n",
320 chname, &expected_uuid,
321 (unsigned long long)expected_min_bytes, bytes);
322 return 0;
323 }
324 }
325 if (expected_version > 0) { /* caller wants us to verify
326 * channel version */
327 unsigned long ver = readl(&((struct channel_header __iomem *)
328 (ch))->version_id);
329 if (ver != expected_version) {
330 pr_err("Channel mismatch on channel=%s(%pUL) field=version expected=0x%-8.8lx actual=0x%-8.8lx\n",
331 chname, &expected_uuid,
332 (unsigned long)expected_version, ver);
333 return 0;
334 }
335 }
336 if (expected_signature > 0) { /* caller wants us to verify
337 * channel signature */
338 unsigned long long sig =
339 readq(&((struct channel_header __iomem *)
340 (ch))->signature);
341 if (sig != expected_signature) {
342 pr_err("Channel mismatch on channel=%s(%pUL) field=signature expected=0x%-8.8llx actual=0x%-8.8llx\n",
343 chname, &expected_uuid,
344 expected_signature, sig);
345 return 0;
346 }
347 }
348 return 1;
349 }
350
351 /* Generic function useful for validating any type of channel when it is about
352 * to be initialized by the server of the channel.
353 * Note that <logCtx> is only needed for callers in the EFI environment, and
354 * is used to pass the EFI_DIAG_CAPTURE_PROTOCOL needed to log messages.
355 */
spar_check_channel_server(uuid_le typeuuid,char * name,u64 expected_min_bytes,u64 actual_bytes)356 static inline int spar_check_channel_server(uuid_le typeuuid, char *name,
357 u64 expected_min_bytes,
358 u64 actual_bytes)
359 {
360 if (expected_min_bytes > 0) /* caller wants us to verify
361 * channel size */
362 if (actual_bytes < expected_min_bytes) {
363 pr_err("Channel mismatch on channel=%s(%pUL) field=size expected=0x%-8.8llx actual=0x%-8.8llx\n",
364 name, &typeuuid, expected_min_bytes,
365 actual_bytes);
366 return 0;
367 }
368 return 1;
369 }
370
371 /* Given a file pathname <s> (with '/' or '\' separating directory nodes),
372 * returns a pointer to the beginning of a node within that pathname such
373 * that the number of nodes from that pointer to the end of the string is
374 * NOT more than <n>. Note that if the pathname has less than <n> nodes
375 * in it, the return pointer will be to the beginning of the string.
376 */
377 static inline u8 *
pathname_last_n_nodes(u8 * s,unsigned int n)378 pathname_last_n_nodes(u8 *s, unsigned int n)
379 {
380 u8 *p = s;
381 unsigned int node_count = 0;
382
383 while (*p != '\0') {
384 if ((*p == '/') || (*p == '\\'))
385 node_count++;
386 p++;
387 }
388 if (node_count <= n)
389 return s;
390 while (n > 0) {
391 p--;
392 if (p == s)
393 break; /* should never happen, unless someone
394 * is changing the string while we are
395 * looking at it!! */
396 if ((*p == '/') || (*p == '\\'))
397 n--;
398 }
399 return p + 1;
400 }
401
402 static inline int
spar_channel_client_acquire_os(void __iomem * ch,u8 * id)403 spar_channel_client_acquire_os(void __iomem *ch, u8 *id)
404 {
405 struct channel_header __iomem *hdr = ch;
406
407 if (readl(&hdr->cli_state_os) == CHANNELCLI_DISABLED) {
408 if ((readb(&hdr->cli_error_os)
409 & ULTRA_CLIERROROS_THROTTLEMSG_DISABLED) == 0) {
410 /* we are NOT throttling this message */
411 writeb(readb(&hdr->cli_error_os) |
412 ULTRA_CLIERROROS_THROTTLEMSG_DISABLED,
413 &hdr->cli_error_os);
414 /* throttle until acquire successful */
415
416 pr_info("%s Channel StateTransition INVALID! - acquire failed because OS client DISABLED\n",
417 id);
418 }
419 return 0;
420 }
421 if ((readl(&hdr->cli_state_os) != CHANNELCLI_OWNED) &&
422 (readl(&hdr->cli_state_boot) == CHANNELCLI_DISABLED)) {
423 /* Our competitor is DISABLED, so we can transition to OWNED */
424 pr_info("%s Channel StateTransition (%s) %s(%d)-->%s(%d)\n",
425 id, "cli_state_os",
426 ULTRA_CHANNELCLI_STRING(readl(&hdr->cli_state_os)),
427 readl(&hdr->cli_state_os),
428 ULTRA_CHANNELCLI_STRING(CHANNELCLI_OWNED),
429 CHANNELCLI_OWNED);
430 writel(CHANNELCLI_OWNED, &hdr->cli_state_os);
431 mb(); /* required for channel synch */
432 }
433 if (readl(&hdr->cli_state_os) == CHANNELCLI_OWNED) {
434 if (readb(&hdr->cli_error_os) != 0) {
435 /* we are in an error msg throttling state;
436 * come out of it */
437 pr_info("%s Channel OS client acquire now successful\n",
438 id);
439 writeb(0, &hdr->cli_error_os);
440 }
441 return 1;
442 }
443
444 /* We have to do it the "hard way". We transition to BUSY,
445 * and can use the channel iff our competitor has not also
446 * transitioned to BUSY. */
447 if (readl(&hdr->cli_state_os) != CHANNELCLI_ATTACHED) {
448 if ((readb(&hdr->cli_error_os)
449 & ULTRA_CLIERROROS_THROTTLEMSG_NOTATTACHED) == 0) {
450 /* we are NOT throttling this message */
451 writeb(readb(&hdr->cli_error_os) |
452 ULTRA_CLIERROROS_THROTTLEMSG_NOTATTACHED,
453 &hdr->cli_error_os);
454 /* throttle until acquire successful */
455 pr_info("%s Channel StateTransition INVALID! - acquire failed because OS client NOT ATTACHED (state=%s(%d))\n",
456 id, ULTRA_CHANNELCLI_STRING(
457 readl(&hdr->cli_state_os)),
458 readl(&hdr->cli_state_os));
459 }
460 return 0;
461 }
462 writel(CHANNELCLI_BUSY, &hdr->cli_state_os);
463 mb(); /* required for channel synch */
464 if (readl(&hdr->cli_state_boot) == CHANNELCLI_BUSY) {
465 if ((readb(&hdr->cli_error_os)
466 & ULTRA_CLIERROROS_THROTTLEMSG_BUSY) == 0) {
467 /* we are NOT throttling this message */
468 writeb(readb(&hdr->cli_error_os) |
469 ULTRA_CLIERROROS_THROTTLEMSG_BUSY,
470 &hdr->cli_error_os);
471 /* throttle until acquire successful */
472 pr_info("%s Channel StateTransition failed - host OS acquire failed because boot BUSY\n",
473 id);
474 }
475 /* reset busy */
476 writel(CHANNELCLI_ATTACHED, &hdr->cli_state_os);
477 mb(); /* required for channel synch */
478 return 0;
479 }
480 if (readb(&hdr->cli_error_os) != 0) {
481 /* we are in an error msg throttling state; come out of it */
482 pr_info("%s Channel OS client acquire now successful\n", id);
483 writeb(0, &hdr->cli_error_os);
484 }
485 return 1;
486 }
487
488 static inline void
spar_channel_client_release_os(void __iomem * ch,u8 * id)489 spar_channel_client_release_os(void __iomem *ch, u8 *id)
490 {
491 struct channel_header __iomem *hdr = ch;
492
493 if (readb(&hdr->cli_error_os) != 0) {
494 /* we are in an error msg throttling state; come out of it */
495 pr_info("%s Channel OS client error state cleared\n", id);
496 writeb(0, &hdr->cli_error_os);
497 }
498 if (readl(&hdr->cli_state_os) == CHANNELCLI_OWNED)
499 return;
500 if (readl(&hdr->cli_state_os) != CHANNELCLI_BUSY) {
501 pr_info("%s Channel StateTransition INVALID! - release failed because OS client NOT BUSY (state=%s(%d))\n",
502 id, ULTRA_CHANNELCLI_STRING(
503 readl(&hdr->cli_state_os)),
504 readl(&hdr->cli_state_os));
505 /* return; */
506 }
507 writel(CHANNELCLI_ATTACHED, &hdr->cli_state_os); /* release busy */
508 }
509
510 /*
511 * Routine Description:
512 * Tries to insert the prebuilt signal pointed to by pSignal into the nth
513 * Queue of the Channel pointed to by pChannel
514 *
515 * Parameters:
516 * pChannel: (IN) points to the IO Channel
517 * Queue: (IN) nth Queue of the IO Channel
518 * pSignal: (IN) pointer to the signal
519 *
520 * Assumptions:
521 * - pChannel, Queue and pSignal are valid.
522 * - If insertion fails due to a full queue, the caller will determine the
523 * retry policy (e.g. wait & try again, report an error, etc.).
524 *
525 * Return value: 1 if the insertion succeeds, 0 if the queue was
526 * full.
527 */
528
529 unsigned char spar_signal_insert(struct channel_header __iomem *ch, u32 queue,
530 void *sig);
531
532 /*
533 * Routine Description:
534 * Removes one signal from Channel pChannel's nth Queue at the
535 * time of the call and copies it into the memory pointed to by
536 * pSignal.
537 *
538 * Parameters:
539 * pChannel: (IN) points to the IO Channel
540 * Queue: (IN) nth Queue of the IO Channel
541 * pSignal: (IN) pointer to where the signals are to be copied
542 *
543 * Assumptions:
544 * - pChannel and Queue are valid.
545 * - pSignal points to a memory area large enough to hold queue's SignalSize
546 *
547 * Return value: 1 if the removal succeeds, 0 if the queue was
548 * empty.
549 */
550
551 unsigned char spar_signal_remove(struct channel_header __iomem *ch, u32 queue,
552 void *sig);
553
554 /*
555 * Routine Description:
556 * Removes all signals present in Channel pChannel's nth Queue at the
557 * time of the call and copies them into the memory pointed to by
558 * pSignal. Returns the # of signals copied as the value of the routine.
559 *
560 * Parameters:
561 * pChannel: (IN) points to the IO Channel
562 * Queue: (IN) nth Queue of the IO Channel
563 * pSignal: (IN) pointer to where the signals are to be copied
564 *
565 * Assumptions:
566 * - pChannel and Queue are valid.
567 * - pSignal points to a memory area large enough to hold Queue's MaxSignals
568 * # of signals, each of which is Queue's SignalSize.
569 *
570 * Return value:
571 * # of signals copied.
572 */
573 unsigned int spar_signal_remove_all(struct channel_header *ch, u32 queue,
574 void *sig);
575
576 /*
577 * Routine Description:
578 * Determine whether a signal queue is empty.
579 *
580 * Parameters:
581 * pChannel: (IN) points to the IO Channel
582 * Queue: (IN) nth Queue of the IO Channel
583 *
584 * Return value:
585 * 1 if the signal queue is empty, 0 otherwise.
586 */
587 unsigned char spar_signalqueue_empty(struct channel_header __iomem *ch,
588 u32 queue);
589
590 #endif
591