Commit | Line | Data |
---|---|---|
3a9c3d12 NC |
1 | /* |
2 | * Copyright (C) 1995 Advanced RISC Machines Limited. All rights reserved. | |
3 | * | |
4 | * This software may be freely used, copied, modified, and distributed | |
5 | * provided that the above copyright notice is preserved in all copies of the | |
6 | * software. | |
7 | */ | |
8 | ||
9 | /* -*-C-*- | |
10 | * | |
11 | * $Revision$ | |
12 | * $Date$ | |
13 | * | |
14 | */ | |
15 | #include <stdio.h> | |
16 | #include <stdlib.h> | |
17 | ||
18 | #include "adp.h" | |
19 | #include "hsys.h" | |
20 | #include "rxtx.h" | |
21 | #include "drivers.h" | |
22 | #include "buffers.h" | |
23 | #include "devclnt.h" | |
24 | #include "adperr.h" | |
25 | #include "devsw.h" | |
26 | #include "hostchan.h" | |
27 | #include "logging.h" | |
28 | ||
29 | /* | |
30 | * TODO: this should be adjustable - it could be done by defining | |
31 | * a reason code for DevSW_Ioctl. It could even be a | |
32 | * per-devicechannel parameter. | |
33 | */ | |
34 | static const unsigned int allocsize = ADP_BUFFER_MIN_SIZE; | |
35 | ||
36 | #define illegalDevChanID(type) ((type) >= DC_NUM_CHANNELS) | |
37 | ||
38 | /**********************************************************************/ | |
39 | ||
40 | /* | |
41 | * Function: initialise_read | |
42 | * Purpose: Set up a read request for another packet | |
43 | * | |
44 | * Params: | |
45 | * In/Out: ds State structure to be initialised | |
46 | * | |
47 | * Returns: | |
48 | * OK: 0 | |
49 | * Error: -1 | |
50 | */ | |
51 | static int initialise_read(DevSWState *ds) | |
52 | { | |
53 | struct data_packet *dp; | |
54 | ||
55 | /* | |
56 | * try to claim the structure that will | |
57 | * eventually hold the new packet. | |
58 | */ | |
59 | if ((ds->ds_nextreadpacket = DevSW_AllocatePacket(allocsize)) == NULL) | |
60 | return -1; | |
61 | ||
62 | /* | |
63 | * Calls into the device driver use the DriverCall structure: use | |
64 | * the buffer we have just allocated, and declare its size. We | |
65 | * are also obliged to clear the driver's context pointer. | |
66 | */ | |
67 | dp = &ds->ds_activeread.dc_packet; | |
68 | dp->buf_len = allocsize; | |
69 | dp->data = ds->ds_nextreadpacket->pk_buffer; | |
70 | ||
71 | ds->ds_activeread.dc_context = NULL; | |
72 | ||
73 | return 0; | |
74 | } | |
75 | ||
76 | /* | |
77 | * Function: initialise_write | |
78 | * Purpose: Set up a write request for another packet | |
79 | * | |
80 | * Params: | |
81 | * Input: packet The packet to be written | |
82 | * | |
83 | * type The type of the packet | |
84 | * | |
85 | * In/Out: dc The structure to be intialised | |
86 | * | |
87 | * Returns: Nothing | |
88 | */ | |
89 | static void initialise_write(DriverCall *dc, Packet *packet, DevChanID type) | |
90 | { | |
91 | struct data_packet *dp = &dc->dc_packet; | |
92 | ||
93 | dp->len = packet->pk_length; | |
94 | dp->data = packet->pk_buffer; | |
95 | dp->type = type; | |
96 | ||
97 | /* | |
98 | * we are required to clear the state structure for the driver | |
99 | */ | |
100 | dc->dc_context = NULL; | |
101 | } | |
102 | ||
103 | /* | |
104 | * Function: enqueue_packet | |
105 | * Purpose: move a newly read packet onto the appropriate queue | |
106 | * of read packets | |
107 | * | |
108 | * Params: | |
109 | * In/Out: ds State structure with new packet | |
110 | * | |
111 | * Returns: Nothing | |
112 | */ | |
113 | static void enqueue_packet(DevSWState *ds) | |
114 | { | |
115 | struct data_packet *dp = &ds->ds_activeread.dc_packet; | |
116 | Packet *packet = ds->ds_nextreadpacket; | |
117 | ||
118 | /* | |
119 | * transfer the length | |
120 | */ | |
121 | packet->pk_length = dp->len; | |
122 | ||
123 | /* | |
124 | * take this packet out of the incoming slot | |
125 | */ | |
126 | ds->ds_nextreadpacket = NULL; | |
127 | ||
128 | /* | |
129 | * try to put it on the correct input queue | |
130 | */ | |
131 | if (illegalDevChanID(dp->type)) | |
132 | { | |
133 | /* this shouldn't happen */ | |
134 | WARN("Illegal type for Rx packet"); | |
135 | DevSW_FreePacket(packet); | |
136 | } | |
137 | else | |
138 | Adp_addToQueue(&ds->ds_readqueue[dp->type], packet); | |
139 | } | |
140 | ||
141 | /* | |
142 | * Function: flush_packet | |
143 | * Purpose: Send a packet to the device driver | |
144 | * | |
145 | * Params: | |
146 | * Input: device The device to be written to | |
147 | * | |
148 | * In/Out: dc Describes the packet to be sent | |
149 | * | |
150 | * Returns: Nothing | |
151 | * | |
152 | * Post-conditions: If the whole packet was accepted by the device | |
153 | * driver, then dc->dc_packet.data will be | |
154 | * set to NULL. | |
155 | */ | |
156 | static void flush_packet(const DeviceDescr *device, DriverCall *dc) | |
157 | { | |
158 | if (device->DeviceWrite(dc) > 0) | |
159 | /* | |
160 | * the whole packet was swallowed | |
161 | */ | |
162 | dc->dc_packet.data = NULL; | |
163 | } | |
164 | ||
165 | /**********************************************************************/ | |
166 | ||
167 | /* | |
168 | * These are the externally visible functions. They are documented in | |
169 | * devsw.h | |
170 | */ | |
171 | Packet *DevSW_AllocatePacket(const unsigned int length) | |
172 | { | |
173 | Packet *pk; | |
174 | ||
175 | if ((pk = malloc(sizeof(*pk))) == NULL) | |
176 | { | |
177 | WARN("malloc failure"); | |
178 | return NULL; | |
179 | } | |
180 | ||
181 | if ((pk->pk_buffer = malloc(length+CHAN_HEADER_SIZE)) == NULL) | |
182 | { | |
183 | WARN("malloc failure"); | |
184 | free(pk); | |
185 | return NULL; | |
186 | } | |
187 | ||
188 | return pk; | |
189 | } | |
190 | ||
191 | void DevSW_FreePacket(Packet *pk) | |
192 | { | |
193 | free(pk->pk_buffer); | |
194 | free(pk); | |
195 | } | |
196 | ||
197 | AdpErrs DevSW_Open(DeviceDescr *device, const char *name, const char *arg, | |
198 | const DevChanID type) | |
199 | { | |
200 | DevSWState *ds; | |
201 | ||
202 | /* | |
203 | * is this the very first open call for this driver? | |
204 | */ | |
205 | if ((ds = (DevSWState *)(device->SwitcherState)) == NULL) | |
206 | { | |
207 | /* | |
208 | * yes, it is: initialise state | |
209 | */ | |
210 | if ((ds = malloc(sizeof(*ds))) == NULL) | |
211 | /* give up */ | |
212 | return adp_malloc_failure; | |
213 | ||
214 | (void)memset(ds, 0, sizeof(*ds)); | |
215 | device->SwitcherState = (void *)ds; | |
216 | } | |
217 | ||
218 | /* | |
219 | * check that we haven't already been opened for this type | |
220 | */ | |
221 | if ((ds->ds_opendevchans & (1 << type)) != 0) | |
222 | return adp_device_already_open; | |
223 | ||
224 | /* | |
225 | * if no opens have been done for this device, then do it now | |
226 | */ | |
227 | if (ds->ds_opendevchans == 0) | |
228 | if (device->DeviceOpen(name, arg) < 0) | |
229 | return adp_device_open_failed; | |
230 | ||
231 | /* | |
232 | * open has finished | |
233 | */ | |
234 | ds->ds_opendevchans |= (1 << type); | |
235 | return adp_ok; | |
236 | } | |
237 | ||
238 | AdpErrs DevSW_Match(const DeviceDescr *device, const char *name, | |
239 | const char *arg) | |
240 | { | |
241 | return (device->DeviceMatch(name, arg) == -1) ? adp_failed : adp_ok; | |
242 | } | |
243 | ||
244 | AdpErrs DevSW_Close(const DeviceDescr *device, const DevChanID type) | |
245 | { | |
246 | DevSWState *ds = (DevSWState *)(device->SwitcherState); | |
247 | Packet *pk; | |
248 | ||
249 | if ((ds->ds_opendevchans & (1 << type)) == 0) | |
250 | return adp_device_not_open; | |
251 | ||
252 | ds->ds_opendevchans &= ~(1 << type); | |
253 | ||
254 | /* | |
255 | * if this is the last close for this channel, then inform the driver | |
256 | */ | |
257 | if (ds->ds_opendevchans == 0) | |
258 | device->DeviceClose(); | |
259 | ||
260 | /* | |
261 | * release all packets of the appropriate type | |
262 | */ | |
263 | for (pk = Adp_removeFromQueue(&(ds->ds_readqueue[type])); | |
264 | pk != NULL; | |
265 | pk = Adp_removeFromQueue(&(ds->ds_readqueue[type]))) | |
266 | DevSW_FreePacket(pk); | |
267 | ||
268 | /* that's all */ | |
269 | return adp_ok; | |
270 | } | |
271 | ||
272 | AdpErrs DevSW_Read(const DeviceDescr *device, const DevChanID type, | |
273 | Packet **packet, bool block) | |
274 | { | |
275 | int read_err; | |
276 | DevSWState *ds = device->SwitcherState; | |
277 | ||
278 | /* | |
279 | * To try to get information out of the device driver as | |
280 | * quickly as possible, we try and read more packets, even | |
281 | * if a completed packet is already available. | |
282 | */ | |
283 | ||
284 | /* | |
285 | * have we got a packet currently pending? | |
286 | */ | |
287 | if (ds->ds_nextreadpacket == NULL) | |
288 | /* | |
289 | * no - set things up | |
290 | */ | |
291 | if (initialise_read(ds) < 0) { | |
292 | /* | |
293 | * we failed to initialise the next packet, but can | |
294 | * still return a packet that has already arrived. | |
295 | */ | |
296 | *packet = Adp_removeFromQueue(&ds->ds_readqueue[type]); | |
297 | return adp_ok; | |
298 | } | |
299 | read_err = device->DeviceRead(&ds->ds_activeread, block); | |
300 | switch (read_err) { | |
301 | case 1: | |
302 | /* | |
303 | * driver has pulled in a complete packet, queue it up | |
304 | */ | |
305 | #ifdef RET_DEBUG | |
306 | printf("got a complete packet\n"); | |
307 | #endif | |
308 | enqueue_packet(ds); | |
309 | *packet = Adp_removeFromQueue(&ds->ds_readqueue[type]); | |
310 | return adp_ok; | |
311 | case 0: | |
312 | /* | |
313 | * OK, return the head of the read queue for the given type | |
314 | */ | |
315 | /* enqueue_packet(ds); */ | |
316 | *packet = Adp_removeFromQueue(&ds->ds_readqueue[type]); | |
317 | return adp_ok; | |
318 | case -1: | |
319 | #ifdef RET_DEBUG | |
320 | printf("got a bad packet\n"); | |
321 | #endif | |
322 | /* bad packet */ | |
323 | *packet = NULL; | |
324 | return adp_bad_packet; | |
325 | default: | |
326 | panic("DevSW_Read: bad read status %d", read_err); | |
327 | } | |
328 | return 0; /* get rid of a potential compiler warning */ | |
329 | } | |
330 | ||
331 | ||
332 | AdpErrs DevSW_FlushPendingWrite(const DeviceDescr *device) | |
333 | { | |
334 | struct DriverCall *dc; | |
335 | struct data_packet *dp; | |
336 | ||
337 | dc = &((DevSWState *)(device->SwitcherState))->ds_activewrite; | |
338 | dp = &dc->dc_packet; | |
339 | ||
340 | /* | |
341 | * try to flush any packet that is still being written | |
342 | */ | |
343 | if (dp->data != NULL) | |
344 | { | |
345 | flush_packet(device, dc); | |
346 | ||
347 | /* see if it has gone */ | |
348 | if (dp->data != NULL) | |
349 | return adp_write_busy; | |
350 | else | |
351 | return adp_ok; | |
352 | } | |
353 | else | |
354 | return adp_ok; | |
355 | } | |
356 | ||
357 | ||
358 | AdpErrs DevSW_Write(const DeviceDescr *device, Packet *packet, DevChanID type) | |
359 | { | |
360 | struct DriverCall *dc; | |
361 | struct data_packet *dp; | |
362 | ||
363 | dc = &((DevSWState *)(device->SwitcherState))->ds_activewrite; | |
364 | dp = &dc->dc_packet; | |
365 | ||
366 | if (illegalDevChanID(type)) | |
367 | return adp_illegal_args; | |
368 | ||
369 | /* | |
370 | * try to flush any packet that is still being written | |
371 | */ | |
372 | if (DevSW_FlushPendingWrite(device) != adp_ok) | |
373 | return adp_write_busy; | |
374 | ||
375 | /* | |
376 | * we can take this packet - set things up, then try to get rid of it | |
377 | */ | |
378 | initialise_write(dc, packet, type); | |
379 | flush_packet(device, dc); | |
380 | ||
381 | return adp_ok; | |
382 | } | |
383 | ||
384 | AdpErrs DevSW_Ioctl(const DeviceDescr *device, const int opcode, void *args) | |
385 | { | |
386 | return (device->DeviceIoctl(opcode, args) < 0) ? adp_failed : adp_ok; | |
387 | } | |
388 | ||
389 | bool DevSW_WriteFinished(const DeviceDescr *device) | |
390 | { | |
391 | struct DriverCall *dc; | |
392 | struct data_packet *dp; | |
393 | ||
394 | dc = &((DevSWState *)(device->SwitcherState))->ds_activewrite; | |
395 | dp = &dc->dc_packet; | |
396 | ||
397 | return (dp == NULL || dp->data == NULL); | |
398 | } | |
399 | ||
400 | /* EOF devsw.c */ |