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Commit | Line | Data |
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1da177e4 | 1 | /* |
1da177e4 | 2 | * S/390 common I/O routines -- low level i/o calls |
1da177e4 | 3 | * |
a53c8fab | 4 | * Copyright IBM Corp. 1999, 2008 |
1da177e4 | 5 | * Author(s): Ingo Adlung (adlung@de.ibm.com) |
4ce3b30c | 6 | * Cornelia Huck (cornelia.huck@de.ibm.com) |
1da177e4 LT |
7 | * Arnd Bergmann (arndb@de.ibm.com) |
8 | * Martin Schwidefsky (schwidefsky@de.ibm.com) | |
9 | */ | |
10 | ||
e6d5a428 ME |
11 | #define KMSG_COMPONENT "cio" |
12 | #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt | |
13 | ||
88dbd203 | 14 | #include <linux/ftrace.h> |
1da177e4 | 15 | #include <linux/module.h> |
1da177e4 LT |
16 | #include <linux/init.h> |
17 | #include <linux/slab.h> | |
18 | #include <linux/device.h> | |
19 | #include <linux/kernel_stat.h> | |
20 | #include <linux/interrupt.h> | |
1da177e4 LT |
21 | #include <asm/cio.h> |
22 | #include <asm/delay.h> | |
23 | #include <asm/irq.h> | |
5a489b98 | 24 | #include <asm/irq_regs.h> |
e87bfe51 | 25 | #include <asm/setup.h> |
15e9b586 | 26 | #include <asm/reset.h> |
46b05d26 | 27 | #include <asm/ipl.h> |
e5854a58 | 28 | #include <asm/chpid.h> |
4e8e56c6 | 29 | #include <asm/airq.h> |
3a3fc29a | 30 | #include <asm/isc.h> |
bfc3f028 | 31 | #include <linux/cputime.h> |
83262d63 | 32 | #include <asm/fcx.h> |
f5daba1d HC |
33 | #include <asm/nmi.h> |
34 | #include <asm/crw.h> | |
1da177e4 LT |
35 | #include "cio.h" |
36 | #include "css.h" | |
37 | #include "chsc.h" | |
38 | #include "ioasm.h" | |
cd6b4f27 | 39 | #include "io_sch.h" |
1da177e4 LT |
40 | #include "blacklist.h" |
41 | #include "cio_debug.h" | |
e6b6e10a | 42 | #include "chp.h" |
1da177e4 LT |
43 | |
44 | debug_info_t *cio_debug_msg_id; | |
45 | debug_info_t *cio_debug_trace_id; | |
46 | debug_info_t *cio_debug_crw_id; | |
47 | ||
1da177e4 LT |
48 | /* |
49 | * Function: cio_debug_init | |
bc698bcf CH |
50 | * Initializes three debug logs for common I/O: |
51 | * - cio_msg logs generic cio messages | |
1da177e4 | 52 | * - cio_trace logs the calling of different functions |
bc698bcf | 53 | * - cio_crw logs machine check related cio messages |
1da177e4 | 54 | */ |
bc698bcf | 55 | static int __init cio_debug_init(void) |
1da177e4 | 56 | { |
361f494d | 57 | cio_debug_msg_id = debug_register("cio_msg", 16, 1, 16 * sizeof(long)); |
1da177e4 LT |
58 | if (!cio_debug_msg_id) |
59 | goto out_unregister; | |
bc698bcf CH |
60 | debug_register_view(cio_debug_msg_id, &debug_sprintf_view); |
61 | debug_set_level(cio_debug_msg_id, 2); | |
361f494d | 62 | cio_debug_trace_id = debug_register("cio_trace", 16, 1, 16); |
1da177e4 LT |
63 | if (!cio_debug_trace_id) |
64 | goto out_unregister; | |
bc698bcf CH |
65 | debug_register_view(cio_debug_trace_id, &debug_hex_ascii_view); |
66 | debug_set_level(cio_debug_trace_id, 2); | |
361f494d | 67 | cio_debug_crw_id = debug_register("cio_crw", 16, 1, 16 * sizeof(long)); |
1da177e4 LT |
68 | if (!cio_debug_crw_id) |
69 | goto out_unregister; | |
bc698bcf CH |
70 | debug_register_view(cio_debug_crw_id, &debug_sprintf_view); |
71 | debug_set_level(cio_debug_crw_id, 4); | |
1da177e4 LT |
72 | return 0; |
73 | ||
74 | out_unregister: | |
75 | if (cio_debug_msg_id) | |
bc698bcf | 76 | debug_unregister(cio_debug_msg_id); |
1da177e4 | 77 | if (cio_debug_trace_id) |
bc698bcf | 78 | debug_unregister(cio_debug_trace_id); |
1da177e4 | 79 | if (cio_debug_crw_id) |
bc698bcf | 80 | debug_unregister(cio_debug_crw_id); |
1da177e4 LT |
81 | return -1; |
82 | } | |
83 | ||
84 | arch_initcall (cio_debug_init); | |
85 | ||
c513d07a | 86 | int cio_set_options(struct subchannel *sch, int flags) |
1da177e4 | 87 | { |
c513d07a | 88 | struct io_subchannel_private *priv = to_io_private(sch); |
1da177e4 | 89 | |
c513d07a SO |
90 | priv->options.suspend = (flags & DOIO_ALLOW_SUSPEND) != 0; |
91 | priv->options.prefetch = (flags & DOIO_DENY_PREFETCH) != 0; | |
92 | priv->options.inter = (flags & DOIO_SUPPRESS_INTER) != 0; | |
93 | return 0; | |
1da177e4 LT |
94 | } |
95 | ||
4d284cac | 96 | static int |
1da177e4 LT |
97 | cio_start_handle_notoper(struct subchannel *sch, __u8 lpm) |
98 | { | |
99 | char dbf_text[15]; | |
100 | ||
101 | if (lpm != 0) | |
102 | sch->lpm &= ~lpm; | |
103 | else | |
104 | sch->lpm = 0; | |
105 | ||
139b83dd | 106 | CIO_MSG_EVENT(2, "cio_start: 'not oper' status for " |
fb6958a5 CH |
107 | "subchannel 0.%x.%04x!\n", sch->schid.ssid, |
108 | sch->schid.sch_no); | |
cdb912a4 SO |
109 | |
110 | if (cio_update_schib(sch)) | |
111 | return -ENODEV; | |
112 | ||
2a0217d5 | 113 | sprintf(dbf_text, "no%s", dev_name(&sch->dev)); |
1da177e4 LT |
114 | CIO_TRACE_EVENT(0, dbf_text); |
115 | CIO_HEX_EVENT(0, &sch->schib, sizeof (struct schib)); | |
116 | ||
117 | return (sch->lpm ? -EACCES : -ENODEV); | |
118 | } | |
119 | ||
120 | int | |
121 | cio_start_key (struct subchannel *sch, /* subchannel structure */ | |
122 | struct ccw1 * cpa, /* logical channel prog addr */ | |
123 | __u8 lpm, /* logical path mask */ | |
124 | __u8 key) /* storage key */ | |
125 | { | |
c513d07a SO |
126 | struct io_subchannel_private *priv = to_io_private(sch); |
127 | union orb *orb = &priv->orb; | |
1da177e4 LT |
128 | int ccode; |
129 | ||
efd986db SO |
130 | CIO_TRACE_EVENT(5, "stIO"); |
131 | CIO_TRACE_EVENT(5, dev_name(&sch->dev)); | |
1da177e4 | 132 | |
9adb8c1d | 133 | memset(orb, 0, sizeof(union orb)); |
1da177e4 | 134 | /* sch is always under 2G. */ |
83262d63 PO |
135 | orb->cmd.intparm = (u32)(addr_t)sch; |
136 | orb->cmd.fmt = 1; | |
1da177e4 | 137 | |
c513d07a SO |
138 | orb->cmd.pfch = priv->options.prefetch == 0; |
139 | orb->cmd.spnd = priv->options.suspend; | |
140 | orb->cmd.ssic = priv->options.suspend && priv->options.inter; | |
83262d63 | 141 | orb->cmd.lpm = (lpm != 0) ? lpm : sch->lpm; |
347a8dc3 | 142 | #ifdef CONFIG_64BIT |
1da177e4 LT |
143 | /* |
144 | * for 64 bit we always support 64 bit IDAWs with 4k page size only | |
145 | */ | |
83262d63 PO |
146 | orb->cmd.c64 = 1; |
147 | orb->cmd.i2k = 0; | |
1da177e4 | 148 | #endif |
83262d63 | 149 | orb->cmd.key = key >> 4; |
1da177e4 | 150 | /* issue "Start Subchannel" */ |
83262d63 | 151 | orb->cmd.cpa = (__u32) __pa(cpa); |
cd6b4f27 | 152 | ccode = ssch(sch->schid, orb); |
1da177e4 LT |
153 | |
154 | /* process condition code */ | |
efd986db | 155 | CIO_HEX_EVENT(5, &ccode, sizeof(ccode)); |
1da177e4 LT |
156 | |
157 | switch (ccode) { | |
158 | case 0: | |
159 | /* | |
160 | * initialize device status information | |
161 | */ | |
23d805b6 | 162 | sch->schib.scsw.cmd.actl |= SCSW_ACTL_START_PEND; |
1da177e4 LT |
163 | return 0; |
164 | case 1: /* status pending */ | |
165 | case 2: /* busy */ | |
166 | return -EBUSY; | |
c91ebe49 | 167 | case 3: /* device/path not operational */ |
1da177e4 | 168 | return cio_start_handle_notoper(sch, lpm); |
c91ebe49 CH |
169 | default: |
170 | return ccode; | |
1da177e4 LT |
171 | } |
172 | } | |
173 | ||
174 | int | |
175 | cio_start (struct subchannel *sch, struct ccw1 *cpa, __u8 lpm) | |
176 | { | |
0b642ede | 177 | return cio_start_key(sch, cpa, lpm, PAGE_DEFAULT_KEY); |
1da177e4 LT |
178 | } |
179 | ||
180 | /* | |
181 | * resume suspended I/O operation | |
182 | */ | |
183 | int | |
184 | cio_resume (struct subchannel *sch) | |
185 | { | |
1da177e4 LT |
186 | int ccode; |
187 | ||
efd986db | 188 | CIO_TRACE_EVENT(4, "resIO"); |
2a0217d5 | 189 | CIO_TRACE_EVENT(4, dev_name(&sch->dev)); |
1da177e4 | 190 | |
a8237fc4 | 191 | ccode = rsch (sch->schid); |
1da177e4 | 192 | |
efd986db | 193 | CIO_HEX_EVENT(4, &ccode, sizeof(ccode)); |
1da177e4 LT |
194 | |
195 | switch (ccode) { | |
196 | case 0: | |
23d805b6 | 197 | sch->schib.scsw.cmd.actl |= SCSW_ACTL_RESUME_PEND; |
1da177e4 LT |
198 | return 0; |
199 | case 1: | |
200 | return -EBUSY; | |
201 | case 2: | |
202 | return -EINVAL; | |
203 | default: | |
204 | /* | |
205 | * useless to wait for request completion | |
206 | * as device is no longer operational ! | |
207 | */ | |
208 | return -ENODEV; | |
209 | } | |
210 | } | |
211 | ||
212 | /* | |
213 | * halt I/O operation | |
214 | */ | |
215 | int | |
216 | cio_halt(struct subchannel *sch) | |
217 | { | |
1da177e4 LT |
218 | int ccode; |
219 | ||
220 | if (!sch) | |
221 | return -ENODEV; | |
222 | ||
efd986db | 223 | CIO_TRACE_EVENT(2, "haltIO"); |
2a0217d5 | 224 | CIO_TRACE_EVENT(2, dev_name(&sch->dev)); |
1da177e4 LT |
225 | |
226 | /* | |
227 | * Issue "Halt subchannel" and process condition code | |
228 | */ | |
a8237fc4 | 229 | ccode = hsch (sch->schid); |
1da177e4 | 230 | |
efd986db | 231 | CIO_HEX_EVENT(2, &ccode, sizeof(ccode)); |
1da177e4 LT |
232 | |
233 | switch (ccode) { | |
234 | case 0: | |
23d805b6 | 235 | sch->schib.scsw.cmd.actl |= SCSW_ACTL_HALT_PEND; |
1da177e4 LT |
236 | return 0; |
237 | case 1: /* status pending */ | |
238 | case 2: /* busy */ | |
239 | return -EBUSY; | |
240 | default: /* device not operational */ | |
241 | return -ENODEV; | |
242 | } | |
243 | } | |
244 | ||
245 | /* | |
246 | * Clear I/O operation | |
247 | */ | |
248 | int | |
249 | cio_clear(struct subchannel *sch) | |
250 | { | |
1da177e4 LT |
251 | int ccode; |
252 | ||
253 | if (!sch) | |
254 | return -ENODEV; | |
255 | ||
efd986db | 256 | CIO_TRACE_EVENT(2, "clearIO"); |
2a0217d5 | 257 | CIO_TRACE_EVENT(2, dev_name(&sch->dev)); |
1da177e4 LT |
258 | |
259 | /* | |
260 | * Issue "Clear subchannel" and process condition code | |
261 | */ | |
a8237fc4 | 262 | ccode = csch (sch->schid); |
1da177e4 | 263 | |
efd986db | 264 | CIO_HEX_EVENT(2, &ccode, sizeof(ccode)); |
1da177e4 LT |
265 | |
266 | switch (ccode) { | |
267 | case 0: | |
23d805b6 | 268 | sch->schib.scsw.cmd.actl |= SCSW_ACTL_CLEAR_PEND; |
1da177e4 LT |
269 | return 0; |
270 | default: /* device not operational */ | |
271 | return -ENODEV; | |
272 | } | |
273 | } | |
274 | ||
275 | /* | |
276 | * Function: cio_cancel | |
277 | * Issues a "Cancel Subchannel" on the specified subchannel | |
278 | * Note: We don't need any fancy intparms and flags here | |
279 | * since xsch is executed synchronously. | |
280 | * Only for common I/O internal use as for now. | |
281 | */ | |
282 | int | |
283 | cio_cancel (struct subchannel *sch) | |
284 | { | |
1da177e4 LT |
285 | int ccode; |
286 | ||
287 | if (!sch) | |
288 | return -ENODEV; | |
289 | ||
efd986db | 290 | CIO_TRACE_EVENT(2, "cancelIO"); |
2a0217d5 | 291 | CIO_TRACE_EVENT(2, dev_name(&sch->dev)); |
1da177e4 | 292 | |
a8237fc4 | 293 | ccode = xsch (sch->schid); |
1da177e4 | 294 | |
efd986db | 295 | CIO_HEX_EVENT(2, &ccode, sizeof(ccode)); |
1da177e4 LT |
296 | |
297 | switch (ccode) { | |
298 | case 0: /* success */ | |
299 | /* Update information in scsw. */ | |
cdb912a4 SO |
300 | if (cio_update_schib(sch)) |
301 | return -ENODEV; | |
1da177e4 LT |
302 | return 0; |
303 | case 1: /* status pending */ | |
304 | return -EBUSY; | |
305 | case 2: /* not applicable */ | |
306 | return -EINVAL; | |
307 | default: /* not oper */ | |
308 | return -ENODEV; | |
309 | } | |
310 | } | |
311 | ||
13952ec1 SO |
312 | |
313 | static void cio_apply_config(struct subchannel *sch, struct schib *schib) | |
314 | { | |
315 | schib->pmcw.intparm = sch->config.intparm; | |
316 | schib->pmcw.mbi = sch->config.mbi; | |
317 | schib->pmcw.isc = sch->config.isc; | |
318 | schib->pmcw.ena = sch->config.ena; | |
319 | schib->pmcw.mme = sch->config.mme; | |
320 | schib->pmcw.mp = sch->config.mp; | |
321 | schib->pmcw.csense = sch->config.csense; | |
322 | schib->pmcw.mbfc = sch->config.mbfc; | |
323 | if (sch->config.mbfc) | |
324 | schib->mba = sch->config.mba; | |
325 | } | |
326 | ||
327 | static int cio_check_config(struct subchannel *sch, struct schib *schib) | |
328 | { | |
329 | return (schib->pmcw.intparm == sch->config.intparm) && | |
330 | (schib->pmcw.mbi == sch->config.mbi) && | |
331 | (schib->pmcw.isc == sch->config.isc) && | |
332 | (schib->pmcw.ena == sch->config.ena) && | |
333 | (schib->pmcw.mme == sch->config.mme) && | |
334 | (schib->pmcw.mp == sch->config.mp) && | |
335 | (schib->pmcw.csense == sch->config.csense) && | |
336 | (schib->pmcw.mbfc == sch->config.mbfc) && | |
337 | (!sch->config.mbfc || (schib->mba == sch->config.mba)); | |
338 | } | |
339 | ||
1da177e4 | 340 | /* |
13952ec1 | 341 | * cio_commit_config - apply configuration to the subchannel |
1da177e4 | 342 | */ |
13952ec1 | 343 | int cio_commit_config(struct subchannel *sch) |
1da177e4 | 344 | { |
13952ec1 SO |
345 | struct schib schib; |
346 | int ccode, retry, ret = 0; | |
347 | ||
8821d24c | 348 | if (stsch_err(sch->schid, &schib) || !css_sch_is_valid(&schib)) |
13952ec1 | 349 | return -ENODEV; |
1da177e4 | 350 | |
1da177e4 | 351 | for (retry = 0; retry < 5; retry++) { |
13952ec1 SO |
352 | /* copy desired changes to local schib */ |
353 | cio_apply_config(sch, &schib); | |
354 | ccode = msch_err(sch->schid, &schib); | |
355 | if (ccode < 0) /* -EIO if msch gets a program check. */ | |
1da177e4 LT |
356 | return ccode; |
357 | switch (ccode) { | |
73ac36ea | 358 | case 0: /* successful */ |
8821d24c | 359 | if (stsch_err(sch->schid, &schib) || |
13952ec1 SO |
360 | !css_sch_is_valid(&schib)) |
361 | return -ENODEV; | |
362 | if (cio_check_config(sch, &schib)) { | |
363 | /* commit changes from local schib */ | |
364 | memcpy(&sch->schib, &schib, sizeof(schib)); | |
365 | return 0; | |
366 | } | |
367 | ret = -EAGAIN; | |
368 | break; | |
369 | case 1: /* status pending */ | |
1da177e4 | 370 | return -EBUSY; |
13952ec1 SO |
371 | case 2: /* busy */ |
372 | udelay(100); /* allow for recovery */ | |
1da177e4 LT |
373 | ret = -EBUSY; |
374 | break; | |
13952ec1 | 375 | case 3: /* not operational */ |
1da177e4 LT |
376 | return -ENODEV; |
377 | } | |
378 | } | |
379 | return ret; | |
380 | } | |
381 | ||
cdb912a4 SO |
382 | /** |
383 | * cio_update_schib - Perform stsch and update schib if subchannel is valid. | |
384 | * @sch: subchannel on which to perform stsch | |
385 | * Return zero on success, -ENODEV otherwise. | |
386 | */ | |
387 | int cio_update_schib(struct subchannel *sch) | |
388 | { | |
389 | struct schib schib; | |
390 | ||
8821d24c | 391 | if (stsch_err(sch->schid, &schib) || !css_sch_is_valid(&schib)) |
cdb912a4 SO |
392 | return -ENODEV; |
393 | ||
394 | memcpy(&sch->schib, &schib, sizeof(schib)); | |
395 | return 0; | |
396 | } | |
397 | EXPORT_SYMBOL_GPL(cio_update_schib); | |
398 | ||
44a1c19e CH |
399 | /** |
400 | * cio_enable_subchannel - enable a subchannel. | |
401 | * @sch: subchannel to be enabled | |
402 | * @intparm: interruption parameter to set | |
1da177e4 | 403 | */ |
edf22096 | 404 | int cio_enable_subchannel(struct subchannel *sch, u32 intparm) |
1da177e4 | 405 | { |
1da177e4 LT |
406 | int retry; |
407 | int ret; | |
408 | ||
efd986db | 409 | CIO_TRACE_EVENT(2, "ensch"); |
2a0217d5 | 410 | CIO_TRACE_EVENT(2, dev_name(&sch->dev)); |
1da177e4 | 411 | |
d7b5a4c9 CH |
412 | if (sch_is_pseudo_sch(sch)) |
413 | return -EINVAL; | |
cdb912a4 | 414 | if (cio_update_schib(sch)) |
1da177e4 LT |
415 | return -ENODEV; |
416 | ||
13952ec1 SO |
417 | sch->config.ena = 1; |
418 | sch->config.isc = sch->isc; | |
419 | sch->config.intparm = intparm; | |
420 | ||
421 | for (retry = 0; retry < 3; retry++) { | |
422 | ret = cio_commit_config(sch); | |
423 | if (ret == -EIO) { | |
1da177e4 | 424 | /* |
13952ec1 | 425 | * Got a program check in msch. Try without |
1da177e4 LT |
426 | * the concurrent sense bit the next time. |
427 | */ | |
13952ec1 SO |
428 | sch->config.csense = 0; |
429 | } else if (ret == -EBUSY) { | |
1da177e4 | 430 | struct irb irb; |
a8237fc4 | 431 | if (tsch(sch->schid, &irb) != 0) |
1da177e4 | 432 | break; |
13952ec1 SO |
433 | } else |
434 | break; | |
1da177e4 | 435 | } |
efd986db | 436 | CIO_HEX_EVENT(2, &ret, sizeof(ret)); |
1da177e4 LT |
437 | return ret; |
438 | } | |
44a1c19e | 439 | EXPORT_SYMBOL_GPL(cio_enable_subchannel); |
1da177e4 | 440 | |
44a1c19e CH |
441 | /** |
442 | * cio_disable_subchannel - disable a subchannel. | |
443 | * @sch: subchannel to disable | |
1da177e4 | 444 | */ |
44a1c19e | 445 | int cio_disable_subchannel(struct subchannel *sch) |
1da177e4 | 446 | { |
ed04b892 | 447 | int retry; |
1da177e4 LT |
448 | int ret; |
449 | ||
efd986db | 450 | CIO_TRACE_EVENT(2, "dissch"); |
2a0217d5 | 451 | CIO_TRACE_EVENT(2, dev_name(&sch->dev)); |
1da177e4 | 452 | |
d7b5a4c9 CH |
453 | if (sch_is_pseudo_sch(sch)) |
454 | return 0; | |
cdb912a4 | 455 | if (cio_update_schib(sch)) |
1da177e4 LT |
456 | return -ENODEV; |
457 | ||
13952ec1 | 458 | sch->config.ena = 0; |
13952ec1 | 459 | |
ed04b892 CH |
460 | for (retry = 0; retry < 3; retry++) { |
461 | ret = cio_commit_config(sch); | |
462 | if (ret == -EBUSY) { | |
463 | struct irb irb; | |
464 | if (tsch(sch->schid, &irb) != 0) | |
465 | break; | |
466 | } else | |
467 | break; | |
468 | } | |
efd986db | 469 | CIO_HEX_EVENT(2, &ret, sizeof(ret)); |
1da177e4 LT |
470 | return ret; |
471 | } | |
44a1c19e | 472 | EXPORT_SYMBOL_GPL(cio_disable_subchannel); |
1da177e4 | 473 | |
b3a686f4 | 474 | static int cio_check_devno_blacklisted(struct subchannel *sch) |
0ae7a7b2 | 475 | { |
0ae7a7b2 CH |
476 | if (is_blacklisted(sch->schid.ssid, sch->schib.pmcw.dev)) { |
477 | /* | |
478 | * This device must not be known to Linux. So we simply | |
479 | * say that there is no device and return ENODEV. | |
480 | */ | |
481 | CIO_MSG_EVENT(6, "Blacklisted device detected " | |
482 | "at devno %04X, subchannel set %x\n", | |
483 | sch->schib.pmcw.dev, sch->schid.ssid); | |
484 | return -ENODEV; | |
485 | } | |
486 | return 0; | |
487 | } | |
488 | ||
b3a686f4 CH |
489 | static int cio_validate_io_subchannel(struct subchannel *sch) |
490 | { | |
491 | /* Initialization for io subchannels. */ | |
492 | if (!css_sch_is_valid(&sch->schib)) | |
493 | return -ENODEV; | |
494 | ||
495 | /* Devno is valid. */ | |
496 | return cio_check_devno_blacklisted(sch); | |
497 | } | |
498 | ||
499 | static int cio_validate_msg_subchannel(struct subchannel *sch) | |
500 | { | |
501 | /* Initialization for message subchannels. */ | |
502 | if (!css_sch_is_valid(&sch->schib)) | |
503 | return -ENODEV; | |
504 | ||
505 | /* Devno is valid. */ | |
506 | return cio_check_devno_blacklisted(sch); | |
507 | } | |
508 | ||
0ae7a7b2 CH |
509 | /** |
510 | * cio_validate_subchannel - basic validation of subchannel | |
511 | * @sch: subchannel structure to be filled out | |
512 | * @schid: subchannel id | |
1da177e4 LT |
513 | * |
514 | * Find out subchannel type and initialize struct subchannel. | |
515 | * Return codes: | |
0ae7a7b2 | 516 | * 0 on success |
1da177e4 | 517 | * -ENXIO for non-defined subchannels |
0ae7a7b2 CH |
518 | * -ENODEV for invalid subchannels or blacklisted devices |
519 | * -EIO for subchannels in an invalid subchannel set | |
1da177e4 | 520 | */ |
0ae7a7b2 | 521 | int cio_validate_subchannel(struct subchannel *sch, struct subchannel_id schid) |
1da177e4 LT |
522 | { |
523 | char dbf_txt[15]; | |
524 | int ccode; | |
2ec22984 | 525 | int err; |
1da177e4 | 526 | |
0ae7a7b2 CH |
527 | sprintf(dbf_txt, "valsch%x", schid.sch_no); |
528 | CIO_TRACE_EVENT(4, dbf_txt); | |
1da177e4 | 529 | |
1da177e4 LT |
530 | /* |
531 | * The first subchannel that is not-operational (ccode==3) | |
e5dcf002 | 532 | * indicates that there aren't any more devices available. |
fb6958a5 | 533 | * If stsch gets an exception, it means the current subchannel set |
e5dcf002 | 534 | * is not valid. |
1da177e4 | 535 | */ |
e5dcf002 | 536 | ccode = stsch_err(schid, &sch->schib); |
2ec22984 CH |
537 | if (ccode) { |
538 | err = (ccode == 3) ? -ENXIO : ccode; | |
539 | goto out; | |
540 | } | |
1da177e4 | 541 | sch->st = sch->schib.pmcw.st; |
e5dcf002 | 542 | sch->schid = schid; |
c820de39 | 543 | |
0ae7a7b2 CH |
544 | switch (sch->st) { |
545 | case SUBCHANNEL_TYPE_IO: | |
546 | err = cio_validate_io_subchannel(sch); | |
547 | break; | |
b3a686f4 CH |
548 | case SUBCHANNEL_TYPE_MSG: |
549 | err = cio_validate_msg_subchannel(sch); | |
550 | break; | |
0ae7a7b2 CH |
551 | default: |
552 | err = 0; | |
1da177e4 | 553 | } |
0ae7a7b2 | 554 | if (err) |
808e4888 | 555 | goto out; |
808e4888 | 556 | |
0ae7a7b2 CH |
557 | CIO_MSG_EVENT(4, "Subchannel 0.%x.%04x reports subchannel type %04X\n", |
558 | sch->schid.ssid, sch->schid.sch_no, sch->st); | |
2ec22984 | 559 | out: |
2ec22984 | 560 | return err; |
1da177e4 LT |
561 | } |
562 | ||
563 | /* | |
1f44a225 | 564 | * do_cio_interrupt() handles all normal I/O device IRQ's |
1da177e4 | 565 | */ |
1f44a225 | 566 | static irqreturn_t do_cio_interrupt(int irq, void *dummy) |
1da177e4 | 567 | { |
1f44a225 | 568 | struct tpi_info *tpi_info; |
1da177e4 LT |
569 | struct subchannel *sch; |
570 | struct irb *irb; | |
571 | ||
4a6f4fe8 | 572 | __this_cpu_write(s390_idle.nohz_delay, 1); |
1f44a225 | 573 | tpi_info = (struct tpi_info *) &get_irq_regs()->int_code; |
48f6b00c | 574 | irb = (struct irb *) &S390_lowcore.irb; |
48f6b00c MS |
575 | sch = (struct subchannel *)(unsigned long) tpi_info->intparm; |
576 | if (!sch) { | |
577 | /* Clear pending interrupt condition. */ | |
578 | inc_irq_stat(IRQIO_CIO); | |
579 | tsch(tpi_info->schid, irb); | |
1f44a225 | 580 | return IRQ_HANDLED; |
48f6b00c MS |
581 | } |
582 | spin_lock(sch->lock); | |
583 | /* Store interrupt response block to lowcore. */ | |
584 | if (tsch(tpi_info->schid, irb) == 0) { | |
585 | /* Keep subchannel information word up to date. */ | |
586 | memcpy (&sch->schib.scsw, &irb->scsw, sizeof (irb->scsw)); | |
587 | /* Call interrupt handler if there is one. */ | |
588 | if (sch->driver && sch->driver->irq) | |
589 | sch->driver->irq(sch); | |
590 | else | |
420f42ec | 591 | inc_irq_stat(IRQIO_CIO); |
48f6b00c MS |
592 | } else |
593 | inc_irq_stat(IRQIO_CIO); | |
594 | spin_unlock(sch->lock); | |
1f44a225 MS |
595 | |
596 | return IRQ_HANDLED; | |
597 | } | |
598 | ||
599 | static struct irq_desc *irq_desc_io; | |
600 | ||
601 | static struct irqaction io_interrupt = { | |
602 | .name = "IO", | |
603 | .handler = do_cio_interrupt, | |
604 | }; | |
605 | ||
606 | void __init init_cio_interrupts(void) | |
607 | { | |
608 | irq_set_chip_and_handler(IO_INTERRUPT, | |
609 | &dummy_irq_chip, handle_percpu_irq); | |
610 | setup_irq(IO_INTERRUPT, &io_interrupt); | |
611 | irq_desc_io = irq_to_desc(IO_INTERRUPT); | |
1da177e4 LT |
612 | } |
613 | ||
614 | #ifdef CONFIG_CCW_CONSOLE | |
863fc849 | 615 | static struct subchannel *console_sch; |
1da177e4 | 616 | |
191fd44c | 617 | /* |
b603d258 | 618 | * Use cio_tsch to update the subchannel status and call the interrupt handler |
188561a4 | 619 | * if status had been pending. Called with the subchannel's lock held. |
191fd44c | 620 | */ |
188561a4 | 621 | void cio_tsch(struct subchannel *sch) |
191fd44c | 622 | { |
191fd44c HC |
623 | struct irb *irb; |
624 | int irq_context; | |
625 | ||
cbb870c8 | 626 | irb = (struct irb *)&S390_lowcore.irb; |
191fd44c | 627 | /* Store interrupt response block to lowcore. */ |
b603d258 | 628 | if (tsch(sch->schid, irb) != 0) |
191fd44c | 629 | /* Not status pending or not operational. */ |
b603d258 MS |
630 | return; |
631 | memcpy(&sch->schib.scsw, &irb->scsw, sizeof(union scsw)); | |
632 | /* Call interrupt handler with updated status. */ | |
191fd44c | 633 | irq_context = in_interrupt(); |
b603d258 | 634 | if (!irq_context) { |
191fd44c | 635 | local_bh_disable(); |
b603d258 MS |
636 | irq_enter(); |
637 | } | |
1f44a225 | 638 | kstat_incr_irqs_this_cpu(IO_INTERRUPT, irq_desc_io); |
191fd44c HC |
639 | if (sch->driver && sch->driver->irq) |
640 | sch->driver->irq(sch); | |
de400d6b | 641 | else |
420f42ec | 642 | inc_irq_stat(IRQIO_CIO); |
b603d258 MS |
643 | if (!irq_context) { |
644 | irq_exit(); | |
191fd44c | 645 | _local_bh_enable(); |
b603d258 | 646 | } |
191fd44c HC |
647 | } |
648 | ||
863fc849 | 649 | static int cio_test_for_console(struct subchannel_id schid, void *data) |
cd6b4f27 | 650 | { |
863fc849 | 651 | struct schib schib; |
cd6b4f27 | 652 | |
863fc849 | 653 | if (stsch_err(schid, &schib) != 0) |
f97a56fb | 654 | return -ENXIO; |
863fc849 SO |
655 | if ((schib.pmcw.st == SUBCHANNEL_TYPE_IO) && schib.pmcw.dnv && |
656 | (schib.pmcw.dev == console_devno)) { | |
f97a56fb CH |
657 | console_irq = schid.sch_no; |
658 | return 1; /* found */ | |
659 | } | |
660 | return 0; | |
661 | } | |
662 | ||
863fc849 | 663 | static int cio_get_console_sch_no(void) |
1da177e4 | 664 | { |
a8237fc4 | 665 | struct subchannel_id schid; |
863fc849 SO |
666 | struct schib schib; |
667 | ||
a8237fc4 | 668 | init_subchannel_id(&schid); |
1da177e4 LT |
669 | if (console_irq != -1) { |
670 | /* VM provided us with the irq number of the console. */ | |
a8237fc4 | 671 | schid.sch_no = console_irq; |
863fc849 SO |
672 | if (stsch_err(schid, &schib) != 0 || |
673 | (schib.pmcw.st != SUBCHANNEL_TYPE_IO) || !schib.pmcw.dnv) | |
1da177e4 | 674 | return -1; |
863fc849 | 675 | console_devno = schib.pmcw.dev; |
1da177e4 LT |
676 | } else if (console_devno != -1) { |
677 | /* At least the console device number is known. */ | |
f97a56fb | 678 | for_each_subchannel(cio_test_for_console, NULL); |
1da177e4 LT |
679 | } |
680 | return console_irq; | |
681 | } | |
682 | ||
863fc849 | 683 | struct subchannel *cio_probe_console(void) |
1da177e4 | 684 | { |
a8237fc4 | 685 | struct subchannel_id schid; |
863fc849 SO |
686 | struct subchannel *sch; |
687 | int sch_no, ret; | |
1da177e4 | 688 | |
f97a56fb CH |
689 | sch_no = cio_get_console_sch_no(); |
690 | if (sch_no == -1) { | |
e6d5a428 | 691 | pr_warning("No CCW console was found\n"); |
1da177e4 LT |
692 | return ERR_PTR(-ENODEV); |
693 | } | |
a8237fc4 | 694 | init_subchannel_id(&schid); |
f97a56fb | 695 | schid.sch_no = sch_no; |
863fc849 SO |
696 | sch = css_alloc_subchannel(schid); |
697 | if (IS_ERR(sch)) | |
698 | return sch; | |
1da177e4 | 699 | |
6ef556cc | 700 | isc_register(CONSOLE_ISC); |
863fc849 SO |
701 | sch->config.isc = CONSOLE_ISC; |
702 | sch->config.intparm = (u32)(addr_t)sch; | |
703 | ret = cio_commit_config(sch); | |
1da177e4 | 704 | if (ret) { |
6ef556cc | 705 | isc_unregister(CONSOLE_ISC); |
863fc849 | 706 | put_device(&sch->dev); |
1da177e4 LT |
707 | return ERR_PTR(ret); |
708 | } | |
863fc849 SO |
709 | console_sch = sch; |
710 | return sch; | |
1da177e4 LT |
711 | } |
712 | ||
863fc849 | 713 | int cio_is_console(struct subchannel_id schid) |
1da177e4 | 714 | { |
863fc849 | 715 | if (!console_sch) |
1da177e4 | 716 | return 0; |
863fc849 | 717 | return schid_equal(&schid, &console_sch->schid); |
1da177e4 LT |
718 | } |
719 | ||
14556b33 | 720 | void cio_register_early_subchannels(void) |
1da177e4 | 721 | { |
14556b33 SO |
722 | int ret; |
723 | ||
724 | if (!console_sch) | |
725 | return; | |
726 | ||
727 | ret = css_register_subchannel(console_sch); | |
728 | if (ret) | |
729 | put_device(&console_sch->dev); | |
1da177e4 | 730 | } |
863fc849 | 731 | #endif /* CONFIG_CCW_CONSOLE */ |
1da177e4 | 732 | |
4d284cac | 733 | static int |
a8237fc4 | 734 | __disable_subchannel_easy(struct subchannel_id schid, struct schib *schib) |
1da177e4 LT |
735 | { |
736 | int retry, cc; | |
737 | ||
738 | cc = 0; | |
739 | for (retry=0;retry<3;retry++) { | |
740 | schib->pmcw.ena = 0; | |
8821d24c | 741 | cc = msch_err(schid, schib); |
1da177e4 LT |
742 | if (cc) |
743 | return (cc==3?-ENODEV:-EBUSY); | |
8821d24c | 744 | if (stsch_err(schid, schib) || !css_sch_is_valid(schib)) |
cdb912a4 | 745 | return -ENODEV; |
1da177e4 LT |
746 | if (!schib->pmcw.ena) |
747 | return 0; | |
748 | } | |
749 | return -EBUSY; /* uhm... */ | |
750 | } | |
751 | ||
4d284cac | 752 | static int |
0ae7a7b2 | 753 | __clear_io_subchannel_easy(struct subchannel_id schid) |
1da177e4 LT |
754 | { |
755 | int retry; | |
756 | ||
757 | if (csch(schid)) | |
758 | return -ENODEV; | |
759 | for (retry=0;retry<20;retry++) { | |
760 | struct tpi_info ti; | |
761 | ||
762 | if (tpi(&ti)) { | |
cbb870c8 | 763 | tsch(ti.schid, (struct irb *)&S390_lowcore.irb); |
a8237fc4 | 764 | if (schid_equal(&ti.schid, &schid)) |
4c24da79 | 765 | return 0; |
1da177e4 | 766 | } |
5a0d0e65 | 767 | udelay_simple(100); |
1da177e4 LT |
768 | } |
769 | return -EBUSY; | |
770 | } | |
771 | ||
9d92a7e1 CH |
772 | static void __clear_chsc_subchannel_easy(void) |
773 | { | |
774 | /* It seems we can only wait for a bit here :/ */ | |
5a0d0e65 | 775 | udelay_simple(100); |
9d92a7e1 CH |
776 | } |
777 | ||
a45e1414 MH |
778 | static int pgm_check_occured; |
779 | ||
780 | static void cio_reset_pgm_check_handler(void) | |
781 | { | |
782 | pgm_check_occured = 1; | |
783 | } | |
784 | ||
f9c9fe3e | 785 | static int stsch_reset(struct subchannel_id schid, struct schib *addr) |
a45e1414 MH |
786 | { |
787 | int rc; | |
788 | ||
789 | pgm_check_occured = 0; | |
ab14de6c | 790 | s390_base_pgm_handler_fn = cio_reset_pgm_check_handler; |
8821d24c | 791 | rc = stsch_err(schid, addr); |
ab14de6c | 792 | s390_base_pgm_handler_fn = NULL; |
aa77015c | 793 | |
ab14de6c | 794 | /* The program check handler could have changed pgm_check_occured. */ |
6faf4444 | 795 | barrier(); |
aa77015c | 796 | |
a45e1414 MH |
797 | if (pgm_check_occured) |
798 | return -EIO; | |
799 | else | |
800 | return rc; | |
801 | } | |
802 | ||
15e9b586 | 803 | static int __shutdown_subchannel_easy(struct subchannel_id schid, void *data) |
f97a56fb CH |
804 | { |
805 | struct schib schib; | |
806 | ||
a45e1414 | 807 | if (stsch_reset(schid, &schib)) |
f97a56fb CH |
808 | return -ENXIO; |
809 | if (!schib.pmcw.ena) | |
810 | return 0; | |
811 | switch(__disable_subchannel_easy(schid, &schib)) { | |
812 | case 0: | |
813 | case -ENODEV: | |
814 | break; | |
815 | default: /* -EBUSY */ | |
0ae7a7b2 CH |
816 | switch (schib.pmcw.st) { |
817 | case SUBCHANNEL_TYPE_IO: | |
818 | if (__clear_io_subchannel_easy(schid)) | |
819 | goto out; /* give up... */ | |
820 | break; | |
9d92a7e1 CH |
821 | case SUBCHANNEL_TYPE_CHSC: |
822 | __clear_chsc_subchannel_easy(); | |
823 | break; | |
0ae7a7b2 CH |
824 | default: |
825 | /* No default clear strategy */ | |
826 | break; | |
827 | } | |
8821d24c | 828 | stsch_err(schid, &schib); |
f97a56fb CH |
829 | __disable_subchannel_easy(schid, &schib); |
830 | } | |
0ae7a7b2 | 831 | out: |
f97a56fb CH |
832 | return 0; |
833 | } | |
1da177e4 | 834 | |
15e9b586 HC |
835 | static atomic_t chpid_reset_count; |
836 | ||
837 | static void s390_reset_chpids_mcck_handler(void) | |
838 | { | |
839 | struct crw crw; | |
840 | struct mci *mci; | |
841 | ||
842 | /* Check for pending channel report word. */ | |
843 | mci = (struct mci *)&S390_lowcore.mcck_interruption_code; | |
844 | if (!mci->cp) | |
845 | return; | |
846 | /* Process channel report words. */ | |
847 | while (stcrw(&crw) == 0) { | |
848 | /* Check for responses to RCHP. */ | |
849 | if (crw.slct && crw.rsc == CRW_RSC_CPATH) | |
850 | atomic_dec(&chpid_reset_count); | |
851 | } | |
852 | } | |
853 | ||
854 | #define RCHP_TIMEOUT (30 * USEC_PER_SEC) | |
855 | static void css_reset(void) | |
856 | { | |
857 | int i, ret; | |
858 | unsigned long long timeout; | |
f86635fa | 859 | struct chp_id chpid; |
15e9b586 HC |
860 | |
861 | /* Reset subchannels. */ | |
862 | for_each_subchannel(__shutdown_subchannel_easy, NULL); | |
863 | /* Reset channel paths. */ | |
ab14de6c | 864 | s390_base_mcck_handler_fn = s390_reset_chpids_mcck_handler; |
15e9b586 HC |
865 | /* Enable channel report machine checks. */ |
866 | __ctl_set_bit(14, 28); | |
867 | /* Temporarily reenable machine checks. */ | |
868 | local_mcck_enable(); | |
f86635fa | 869 | chp_id_init(&chpid); |
15e9b586 | 870 | for (i = 0; i <= __MAX_CHPID; i++) { |
f86635fa PO |
871 | chpid.id = i; |
872 | ret = rchp(chpid); | |
15e9b586 HC |
873 | if ((ret == 0) || (ret == 2)) |
874 | /* | |
875 | * rchp either succeeded, or another rchp is already | |
876 | * in progress. In either case, we'll get a crw. | |
877 | */ | |
878 | atomic_inc(&chpid_reset_count); | |
879 | } | |
880 | /* Wait for machine check for all channel paths. */ | |
8c071b0f | 881 | timeout = get_tod_clock_fast() + (RCHP_TIMEOUT << 12); |
15e9b586 | 882 | while (atomic_read(&chpid_reset_count) != 0) { |
8c071b0f | 883 | if (get_tod_clock_fast() > timeout) |
15e9b586 HC |
884 | break; |
885 | cpu_relax(); | |
886 | } | |
887 | /* Disable machine checks again. */ | |
888 | local_mcck_disable(); | |
889 | /* Disable channel report machine checks. */ | |
890 | __ctl_clear_bit(14, 28); | |
ab14de6c | 891 | s390_base_mcck_handler_fn = NULL; |
15e9b586 HC |
892 | } |
893 | ||
894 | static struct reset_call css_reset_call = { | |
895 | .fn = css_reset, | |
896 | }; | |
897 | ||
898 | static int __init init_css_reset_call(void) | |
899 | { | |
900 | atomic_set(&chpid_reset_count, 0); | |
901 | register_reset_call(&css_reset_call); | |
902 | return 0; | |
903 | } | |
904 | ||
905 | arch_initcall(init_css_reset_call); | |
906 | ||
907 | struct sch_match_id { | |
908 | struct subchannel_id schid; | |
909 | struct ccw_dev_id devid; | |
910 | int rc; | |
911 | }; | |
912 | ||
913 | static int __reipl_subchannel_match(struct subchannel_id schid, void *data) | |
914 | { | |
915 | struct schib schib; | |
916 | struct sch_match_id *match_id = data; | |
917 | ||
a45e1414 | 918 | if (stsch_reset(schid, &schib)) |
15e9b586 | 919 | return -ENXIO; |
b279a4f5 | 920 | if ((schib.pmcw.st == SUBCHANNEL_TYPE_IO) && schib.pmcw.dnv && |
15e9b586 HC |
921 | (schib.pmcw.dev == match_id->devid.devno) && |
922 | (schid.ssid == match_id->devid.ssid)) { | |
923 | match_id->schid = schid; | |
924 | match_id->rc = 0; | |
925 | return 1; | |
926 | } | |
927 | return 0; | |
928 | } | |
929 | ||
930 | static int reipl_find_schid(struct ccw_dev_id *devid, | |
931 | struct subchannel_id *schid) | |
1da177e4 | 932 | { |
ff6b8ea6 MH |
933 | struct sch_match_id match_id; |
934 | ||
935 | match_id.devid = *devid; | |
936 | match_id.rc = -ENODEV; | |
15e9b586 | 937 | for_each_subchannel(__reipl_subchannel_match, &match_id); |
ff6b8ea6 MH |
938 | if (match_id.rc == 0) |
939 | *schid = match_id.schid; | |
940 | return match_id.rc; | |
1da177e4 LT |
941 | } |
942 | ||
ff6b8ea6 MH |
943 | extern void do_reipl_asm(__u32 schid); |
944 | ||
1da177e4 | 945 | /* Make sure all subchannels are quiet before we re-ipl an lpar. */ |
ff6b8ea6 | 946 | void reipl_ccw_dev(struct ccw_dev_id *devid) |
1da177e4 | 947 | { |
41459d36 | 948 | struct subchannel_id uninitialized_var(schid); |
ff6b8ea6 | 949 | |
60a0c68d | 950 | s390_reset_system(NULL, NULL); |
15e9b586 | 951 | if (reipl_find_schid(devid, &schid) != 0) |
ff6b8ea6 | 952 | panic("IPL Device not found\n"); |
ff6b8ea6 | 953 | do_reipl_asm(*((__u32*)&schid)); |
1da177e4 | 954 | } |
e87bfe51 | 955 | |
6fc321fd | 956 | int __init cio_get_iplinfo(struct cio_iplinfo *iplinfo) |
e87bfe51 HC |
957 | { |
958 | struct subchannel_id schid; | |
6fc321fd | 959 | struct schib schib; |
e87bfe51 | 960 | |
cbb870c8 | 961 | schid = *(struct subchannel_id *)&S390_lowcore.subchannel_id; |
e87bfe51 | 962 | if (!schid.one) |
6fc321fd | 963 | return -ENODEV; |
8821d24c | 964 | if (stsch_err(schid, &schib)) |
6fc321fd | 965 | return -ENODEV; |
b279a4f5 CH |
966 | if (schib.pmcw.st != SUBCHANNEL_TYPE_IO) |
967 | return -ENODEV; | |
6fc321fd HC |
968 | if (!schib.pmcw.dnv) |
969 | return -ENODEV; | |
970 | iplinfo->devno = schib.pmcw.dev; | |
971 | iplinfo->is_qdio = schib.pmcw.qf; | |
972 | return 0; | |
e87bfe51 | 973 | } |
83262d63 PO |
974 | |
975 | /** | |
976 | * cio_tm_start_key - perform start function | |
977 | * @sch: subchannel on which to perform the start function | |
978 | * @tcw: transport-command word to be started | |
979 | * @lpm: mask of paths to use | |
980 | * @key: storage key to use for storage access | |
981 | * | |
982 | * Start the tcw on the given subchannel. Return zero on success, non-zero | |
983 | * otherwise. | |
984 | */ | |
985 | int cio_tm_start_key(struct subchannel *sch, struct tcw *tcw, u8 lpm, u8 key) | |
986 | { | |
987 | int cc; | |
988 | union orb *orb = &to_io_private(sch)->orb; | |
989 | ||
990 | memset(orb, 0, sizeof(union orb)); | |
991 | orb->tm.intparm = (u32) (addr_t) sch; | |
992 | orb->tm.key = key >> 4; | |
993 | orb->tm.b = 1; | |
994 | orb->tm.lpm = lpm ? lpm : sch->lpm; | |
995 | orb->tm.tcw = (u32) (addr_t) tcw; | |
996 | cc = ssch(sch->schid, orb); | |
997 | switch (cc) { | |
998 | case 0: | |
999 | return 0; | |
1000 | case 1: | |
1001 | case 2: | |
1002 | return -EBUSY; | |
1003 | default: | |
1004 | return cio_start_handle_notoper(sch, lpm); | |
1005 | } | |
1006 | } | |
1007 | ||
1008 | /** | |
1009 | * cio_tm_intrg - perform interrogate function | |
1010 | * @sch - subchannel on which to perform the interrogate function | |
1011 | * | |
1012 | * If the specified subchannel is running in transport-mode, perform the | |
1013 | * interrogate function. Return zero on success, non-zero otherwie. | |
1014 | */ | |
1015 | int cio_tm_intrg(struct subchannel *sch) | |
1016 | { | |
1017 | int cc; | |
1018 | ||
1019 | if (!to_io_private(sch)->orb.tm.b) | |
1020 | return -EINVAL; | |
1021 | cc = xsch(sch->schid); | |
1022 | switch (cc) { | |
1023 | case 0: | |
1024 | case 2: | |
1025 | return 0; | |
1026 | case 1: | |
1027 | return -EBUSY; | |
1028 | default: | |
1029 | return -ENODEV; | |
1030 | } | |
1031 | } |