1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * SN Platform GRU Driver
4 *
5 * KERNEL SERVICES THAT USE THE GRU
6 *
7 * Copyright (c) 2008 Silicon Graphics, Inc. All Rights Reserved.
8 */
9
10 #include <linux/kernel.h>
11 #include <linux/errno.h>
12 #include <linux/slab.h>
13 #include <linux/mm.h>
14 #include <linux/spinlock.h>
15 #include <linux/device.h>
16 #include <linux/miscdevice.h>
17 #include <linux/proc_fs.h>
18 #include <linux/interrupt.h>
19 #include <linux/sync_core.h>
20 #include <linux/uaccess.h>
21 #include <linux/delay.h>
22 #include <linux/export.h>
23 #include <asm/io_apic.h>
24 #include "gru.h"
25 #include "grulib.h"
26 #include "grutables.h"
27 #include "grukservices.h"
28 #include "gru_instructions.h"
29 #include <asm/uv/uv_hub.h>
30
31 /*
32 * Kernel GRU Usage
33 *
34 * The following is an interim algorithm for management of kernel GRU
35 * resources. This will likely be replaced when we better understand the
36 * kernel/user requirements.
37 *
38 * Blade percpu resources reserved for kernel use. These resources are
39 * reserved whenever the kernel context for the blade is loaded. Note
40 * that the kernel context is not guaranteed to be always available. It is
41 * loaded on demand & can be stolen by a user if the user demand exceeds the
42 * kernel demand. The kernel can always reload the kernel context but
43 * a SLEEP may be required!!!.
44 *
45 * Async Overview:
46 *
47 * Each blade has one "kernel context" that owns GRU kernel resources
48 * located on the blade. Kernel drivers use GRU resources in this context
49 * for sending messages, zeroing memory, etc.
50 *
51 * The kernel context is dynamically loaded on demand. If it is not in
52 * use by the kernel, the kernel context can be unloaded & given to a user.
53 * The kernel context will be reloaded when needed. This may require that
54 * a context be stolen from a user.
55 * NOTE: frequent unloading/reloading of the kernel context is
56 * expensive. We are depending on batch schedulers, cpusets, sane
57 * drivers or some other mechanism to prevent the need for frequent
58 * stealing/reloading.
59 *
60 * The kernel context consists of two parts:
61 * - 1 CB & a few DSRs that are reserved for each cpu on the blade.
62 * Each cpu has it's own private resources & does not share them
63 * with other cpus. These resources are used serially, ie,
64 * locked, used & unlocked on each call to a function in
65 * grukservices.
66 * (Now that we have dynamic loading of kernel contexts, I
67 * may rethink this & allow sharing between cpus....)
68 *
69 * - Additional resources can be reserved long term & used directly
70 * by UV drivers located in the kernel. Drivers using these GRU
71 * resources can use asynchronous GRU instructions that send
72 * interrupts on completion.
73 * - these resources must be explicitly locked/unlocked
74 * - locked resources prevent (obviously) the kernel
75 * context from being unloaded.
76 * - drivers using these resource directly issue their own
77 * GRU instruction and must wait/check completion.
78 *
79 * When these resources are reserved, the caller can optionally
80 * associate a wait_queue with the resources and use asynchronous
81 * GRU instructions. When an async GRU instruction completes, the
82 * driver will do a wakeup on the event.
83 *
84 */
85
86
87 #define ASYNC_HAN_TO_BID(h) ((h) - 1)
88 #define ASYNC_BID_TO_HAN(b) ((b) + 1)
89 #define ASYNC_HAN_TO_BS(h) gru_base[ASYNC_HAN_TO_BID(h)]
90
91 #define GRU_NUM_KERNEL_CBR 1
92 #define GRU_NUM_KERNEL_DSR_BYTES 256
93 #define GRU_NUM_KERNEL_DSR_CL (GRU_NUM_KERNEL_DSR_BYTES / \
94 GRU_CACHE_LINE_BYTES)
95
96 /* GRU instruction attributes for all instructions */
97 #define IMA IMA_CB_DELAY
98
99 /* GRU cacheline size is always 64 bytes - even on arches with 128 byte lines */
100 #define __gru_cacheline_aligned__ \
101 __attribute__((__aligned__(GRU_CACHE_LINE_BYTES)))
102
103 #define MAGIC 0x1234567887654321UL
104
105 /* Default retry count for GRU errors on kernel instructions */
106 #define EXCEPTION_RETRY_LIMIT 3
107
108 /* Status of message queue sections */
109 #define MQS_EMPTY 0
110 #define MQS_FULL 1
111 #define MQS_NOOP 2
112
113 /*----------------- RESOURCE MANAGEMENT -------------------------------------*/
114 /* optimized for x86_64 */
115 struct message_queue {
116 union gru_mesqhead head __gru_cacheline_aligned__; /* CL 0 */
117 int qlines; /* DW 1 */
118 long hstatus[2];
119 void *next __gru_cacheline_aligned__;/* CL 1 */
120 void *limit;
121 void *start;
122 void *start2;
123 char data ____cacheline_aligned; /* CL 2 */
124 };
125
126 /* First word in every message - used by mesq interface */
127 struct message_header {
128 char present;
129 char present2;
130 char lines;
131 char fill;
132 };
133
134 #define HSTATUS(mq, h) ((mq) + offsetof(struct message_queue, hstatus[h]))
135
136 /*
137 * Reload the blade's kernel context into a GRU chiplet. Called holding
138 * the bs_kgts_sema for READ. Will steal user contexts if necessary.
139 */
gru_load_kernel_context(struct gru_blade_state * bs,int blade_id)140 static void gru_load_kernel_context(struct gru_blade_state *bs, int blade_id)
141 {
142 struct gru_state *gru;
143 struct gru_thread_state *kgts;
144 void *vaddr;
145 int ctxnum, ncpus;
146
147 up_read(&bs->bs_kgts_sema);
148 down_write(&bs->bs_kgts_sema);
149
150 if (!bs->bs_kgts) {
151 do {
152 bs->bs_kgts = gru_alloc_gts(NULL, 0, 0, 0, 0, 0);
153 if (!IS_ERR(bs->bs_kgts))
154 break;
155 msleep(1);
156 } while (true);
157 bs->bs_kgts->ts_user_blade_id = blade_id;
158 }
159 kgts = bs->bs_kgts;
160
161 if (!kgts->ts_gru) {
162 STAT(load_kernel_context);
163 ncpus = uv_blade_nr_possible_cpus(blade_id);
164 kgts->ts_cbr_au_count = GRU_CB_COUNT_TO_AU(
165 GRU_NUM_KERNEL_CBR * ncpus + bs->bs_async_cbrs);
166 kgts->ts_dsr_au_count = GRU_DS_BYTES_TO_AU(
167 GRU_NUM_KERNEL_DSR_BYTES * ncpus +
168 bs->bs_async_dsr_bytes);
169 while (!gru_assign_gru_context(kgts)) {
170 msleep(1);
171 gru_steal_context(kgts);
172 }
173 gru_load_context(kgts);
174 gru = bs->bs_kgts->ts_gru;
175 vaddr = gru->gs_gru_base_vaddr;
176 ctxnum = kgts->ts_ctxnum;
177 bs->kernel_cb = get_gseg_base_address_cb(vaddr, ctxnum, 0);
178 bs->kernel_dsr = get_gseg_base_address_ds(vaddr, ctxnum, 0);
179 }
180 downgrade_write(&bs->bs_kgts_sema);
181 }
182
183 /*
184 * Free all kernel contexts that are not currently in use.
185 * Returns 0 if all freed, else number of inuse context.
186 */
gru_free_kernel_contexts(void)187 static int gru_free_kernel_contexts(void)
188 {
189 struct gru_blade_state *bs;
190 struct gru_thread_state *kgts;
191 int bid, ret = 0;
192
193 for (bid = 0; bid < GRU_MAX_BLADES; bid++) {
194 bs = gru_base[bid];
195 if (!bs)
196 continue;
197
198 /* Ignore busy contexts. Don't want to block here. */
199 if (down_write_trylock(&bs->bs_kgts_sema)) {
200 kgts = bs->bs_kgts;
201 if (kgts && kgts->ts_gru)
202 gru_unload_context(kgts, 0);
203 bs->bs_kgts = NULL;
204 up_write(&bs->bs_kgts_sema);
205 kfree(kgts);
206 } else {
207 ret++;
208 }
209 }
210 return ret;
211 }
212
213 /*
214 * Lock & load the kernel context for the specified blade.
215 */
gru_lock_kernel_context(int blade_id)216 static struct gru_blade_state *gru_lock_kernel_context(int blade_id)
217 {
218 struct gru_blade_state *bs;
219 int bid;
220
221 STAT(lock_kernel_context);
222 again:
223 bid = blade_id < 0 ? uv_numa_blade_id() : blade_id;
224 bs = gru_base[bid];
225
226 /* Handle the case where migration occurred while waiting for the sema */
227 down_read(&bs->bs_kgts_sema);
228 if (blade_id < 0 && bid != uv_numa_blade_id()) {
229 up_read(&bs->bs_kgts_sema);
230 goto again;
231 }
232 if (!bs->bs_kgts || !bs->bs_kgts->ts_gru)
233 gru_load_kernel_context(bs, bid);
234 return bs;
235
236 }
237
238 /*
239 * Unlock the kernel context for the specified blade. Context is not
240 * unloaded but may be stolen before next use.
241 */
gru_unlock_kernel_context(int blade_id)242 static void gru_unlock_kernel_context(int blade_id)
243 {
244 struct gru_blade_state *bs;
245
246 bs = gru_base[blade_id];
247 up_read(&bs->bs_kgts_sema);
248 STAT(unlock_kernel_context);
249 }
250
251 /*
252 * Reserve & get pointers to the DSR/CBRs reserved for the current cpu.
253 * - returns with preemption disabled
254 */
gru_get_cpu_resources(int dsr_bytes,void ** cb,void ** dsr)255 static int gru_get_cpu_resources(int dsr_bytes, void **cb, void **dsr)
256 {
257 struct gru_blade_state *bs;
258 int lcpu;
259
260 BUG_ON(dsr_bytes > GRU_NUM_KERNEL_DSR_BYTES);
261 bs = gru_lock_kernel_context(-1);
262 lcpu = uv_blade_processor_id();
263 *cb = bs->kernel_cb + lcpu * GRU_HANDLE_STRIDE;
264 *dsr = bs->kernel_dsr + lcpu * GRU_NUM_KERNEL_DSR_BYTES;
265 return 0;
266 }
267
268 /*
269 * Free the current cpus reserved DSR/CBR resources.
270 */
gru_free_cpu_resources(void * cb,void * dsr)271 static void gru_free_cpu_resources(void *cb, void *dsr)
272 {
273 gru_unlock_kernel_context(uv_numa_blade_id());
274 }
275
276 /*
277 * Reserve GRU resources to be used asynchronously.
278 * Note: currently supports only 1 reservation per blade.
279 *
280 * input:
281 * blade_id - blade on which resources should be reserved
282 * cbrs - number of CBRs
283 * dsr_bytes - number of DSR bytes needed
284 * output:
285 * handle to identify resource
286 * (0 = async resources already reserved)
287 */
gru_reserve_async_resources(int blade_id,int cbrs,int dsr_bytes,struct completion * cmp)288 unsigned long gru_reserve_async_resources(int blade_id, int cbrs, int dsr_bytes,
289 struct completion *cmp)
290 {
291 struct gru_blade_state *bs;
292 struct gru_thread_state *kgts;
293 int ret = 0;
294
295 bs = gru_base[blade_id];
296
297 down_write(&bs->bs_kgts_sema);
298
299 /* Verify no resources already reserved */
300 if (bs->bs_async_dsr_bytes + bs->bs_async_cbrs)
301 goto done;
302 bs->bs_async_dsr_bytes = dsr_bytes;
303 bs->bs_async_cbrs = cbrs;
304 bs->bs_async_wq = cmp;
305 kgts = bs->bs_kgts;
306
307 /* Resources changed. Unload context if already loaded */
308 if (kgts && kgts->ts_gru)
309 gru_unload_context(kgts, 0);
310 ret = ASYNC_BID_TO_HAN(blade_id);
311
312 done:
313 up_write(&bs->bs_kgts_sema);
314 return ret;
315 }
316
317 /*
318 * Release async resources previously reserved.
319 *
320 * input:
321 * han - handle to identify resources
322 */
gru_release_async_resources(unsigned long han)323 void gru_release_async_resources(unsigned long han)
324 {
325 struct gru_blade_state *bs = ASYNC_HAN_TO_BS(han);
326
327 down_write(&bs->bs_kgts_sema);
328 bs->bs_async_dsr_bytes = 0;
329 bs->bs_async_cbrs = 0;
330 bs->bs_async_wq = NULL;
331 up_write(&bs->bs_kgts_sema);
332 }
333
334 /*
335 * Wait for async GRU instructions to complete.
336 *
337 * input:
338 * han - handle to identify resources
339 */
gru_wait_async_cbr(unsigned long han)340 void gru_wait_async_cbr(unsigned long han)
341 {
342 struct gru_blade_state *bs = ASYNC_HAN_TO_BS(han);
343
344 wait_for_completion(bs->bs_async_wq);
345 mb();
346 }
347
348 /*
349 * Lock previous reserved async GRU resources
350 *
351 * input:
352 * han - handle to identify resources
353 * output:
354 * cb - pointer to first CBR
355 * dsr - pointer to first DSR
356 */
gru_lock_async_resource(unsigned long han,void ** cb,void ** dsr)357 void gru_lock_async_resource(unsigned long han, void **cb, void **dsr)
358 {
359 struct gru_blade_state *bs = ASYNC_HAN_TO_BS(han);
360 int blade_id = ASYNC_HAN_TO_BID(han);
361 int ncpus;
362
363 gru_lock_kernel_context(blade_id);
364 ncpus = uv_blade_nr_possible_cpus(blade_id);
365 if (cb)
366 *cb = bs->kernel_cb + ncpus * GRU_HANDLE_STRIDE;
367 if (dsr)
368 *dsr = bs->kernel_dsr + ncpus * GRU_NUM_KERNEL_DSR_BYTES;
369 }
370
371 /*
372 * Unlock previous reserved async GRU resources
373 *
374 * input:
375 * han - handle to identify resources
376 */
gru_unlock_async_resource(unsigned long han)377 void gru_unlock_async_resource(unsigned long han)
378 {
379 int blade_id = ASYNC_HAN_TO_BID(han);
380
381 gru_unlock_kernel_context(blade_id);
382 }
383
384 /*----------------------------------------------------------------------*/
gru_get_cb_exception_detail(void * cb,struct control_block_extended_exc_detail * excdet)385 int gru_get_cb_exception_detail(void *cb,
386 struct control_block_extended_exc_detail *excdet)
387 {
388 struct gru_control_block_extended *cbe;
389 struct gru_thread_state *kgts = NULL;
390 unsigned long off;
391 int cbrnum, bid;
392
393 /*
394 * Locate kgts for cb. This algorithm is SLOW but
395 * this function is rarely called (ie., almost never).
396 * Performance does not matter.
397 */
398 for_each_possible_blade(bid) {
399 if (!gru_base[bid])
400 break;
401 kgts = gru_base[bid]->bs_kgts;
402 if (!kgts || !kgts->ts_gru)
403 continue;
404 off = cb - kgts->ts_gru->gs_gru_base_vaddr;
405 if (off < GRU_SIZE)
406 break;
407 kgts = NULL;
408 }
409 BUG_ON(!kgts);
410 cbrnum = thread_cbr_number(kgts, get_cb_number(cb));
411 cbe = get_cbe(GRUBASE(cb), cbrnum);
412 gru_flush_cache(cbe); /* CBE not coherent */
413 sync_core();
414 excdet->opc = cbe->opccpy;
415 excdet->exopc = cbe->exopccpy;
416 excdet->ecause = cbe->ecause;
417 excdet->exceptdet0 = cbe->idef1upd;
418 excdet->exceptdet1 = cbe->idef3upd;
419 gru_flush_cache(cbe);
420 return 0;
421 }
422
gru_get_cb_exception_detail_str(int ret,void * cb,char * buf,int size)423 static char *gru_get_cb_exception_detail_str(int ret, void *cb,
424 char *buf, int size)
425 {
426 struct gru_control_block_status *gen = cb;
427 struct control_block_extended_exc_detail excdet;
428
429 if (ret > 0 && gen->istatus == CBS_EXCEPTION) {
430 gru_get_cb_exception_detail(cb, &excdet);
431 snprintf(buf, size,
432 "GRU:%d exception: cb %p, opc %d, exopc %d, ecause 0x%x,"
433 "excdet0 0x%lx, excdet1 0x%x", smp_processor_id(),
434 gen, excdet.opc, excdet.exopc, excdet.ecause,
435 excdet.exceptdet0, excdet.exceptdet1);
436 } else {
437 snprintf(buf, size, "No exception");
438 }
439 return buf;
440 }
441
gru_wait_idle_or_exception(struct gru_control_block_status * gen)442 static int gru_wait_idle_or_exception(struct gru_control_block_status *gen)
443 {
444 while (gen->istatus >= CBS_ACTIVE) {
445 cpu_relax();
446 barrier();
447 }
448 return gen->istatus;
449 }
450
gru_retry_exception(void * cb)451 static int gru_retry_exception(void *cb)
452 {
453 struct gru_control_block_status *gen = cb;
454 struct control_block_extended_exc_detail excdet;
455 int retry = EXCEPTION_RETRY_LIMIT;
456
457 while (1) {
458 if (gru_wait_idle_or_exception(gen) == CBS_IDLE)
459 return CBS_IDLE;
460 if (gru_get_cb_message_queue_substatus(cb))
461 return CBS_EXCEPTION;
462 gru_get_cb_exception_detail(cb, &excdet);
463 if ((excdet.ecause & ~EXCEPTION_RETRY_BITS) ||
464 (excdet.cbrexecstatus & CBR_EXS_ABORT_OCC))
465 break;
466 if (retry-- == 0)
467 break;
468 gen->icmd = 1;
469 gru_flush_cache(gen);
470 }
471 return CBS_EXCEPTION;
472 }
473
gru_check_status_proc(void * cb)474 int gru_check_status_proc(void *cb)
475 {
476 struct gru_control_block_status *gen = cb;
477 int ret;
478
479 ret = gen->istatus;
480 if (ret == CBS_EXCEPTION)
481 ret = gru_retry_exception(cb);
482 rmb();
483 return ret;
484
485 }
486
gru_wait_proc(void * cb)487 int gru_wait_proc(void *cb)
488 {
489 struct gru_control_block_status *gen = cb;
490 int ret;
491
492 ret = gru_wait_idle_or_exception(gen);
493 if (ret == CBS_EXCEPTION)
494 ret = gru_retry_exception(cb);
495 rmb();
496 return ret;
497 }
498
gru_abort(int ret,void * cb,char * str)499 static void gru_abort(int ret, void *cb, char *str)
500 {
501 char buf[GRU_EXC_STR_SIZE];
502
503 panic("GRU FATAL ERROR: %s - %s\n", str,
504 gru_get_cb_exception_detail_str(ret, cb, buf, sizeof(buf)));
505 }
506
gru_wait_abort_proc(void * cb)507 void gru_wait_abort_proc(void *cb)
508 {
509 int ret;
510
511 ret = gru_wait_proc(cb);
512 if (ret)
513 gru_abort(ret, cb, "gru_wait_abort");
514 }
515
516
517 /*------------------------------ MESSAGE QUEUES -----------------------------*/
518
519 /* Internal status . These are NOT returned to the user. */
520 #define MQIE_AGAIN -1 /* try again */
521
522
523 /*
524 * Save/restore the "present" flag that is in the second line of 2-line
525 * messages
526 */
get_present2(void * p)527 static inline int get_present2(void *p)
528 {
529 struct message_header *mhdr = p + GRU_CACHE_LINE_BYTES;
530 return mhdr->present;
531 }
532
restore_present2(void * p,int val)533 static inline void restore_present2(void *p, int val)
534 {
535 struct message_header *mhdr = p + GRU_CACHE_LINE_BYTES;
536 mhdr->present = val;
537 }
538
539 /*
540 * Create a message queue.
541 * qlines - message queue size in cache lines. Includes 2-line header.
542 */
gru_create_message_queue(struct gru_message_queue_desc * mqd,void * p,unsigned int bytes,int nasid,int vector,int apicid)543 int gru_create_message_queue(struct gru_message_queue_desc *mqd,
544 void *p, unsigned int bytes, int nasid, int vector, int apicid)
545 {
546 struct message_queue *mq = p;
547 unsigned int qlines;
548
549 qlines = bytes / GRU_CACHE_LINE_BYTES - 2;
550 memset(mq, 0, bytes);
551 mq->start = &mq->data;
552 mq->start2 = &mq->data + (qlines / 2 - 1) * GRU_CACHE_LINE_BYTES;
553 mq->next = &mq->data;
554 mq->limit = &mq->data + (qlines - 2) * GRU_CACHE_LINE_BYTES;
555 mq->qlines = qlines;
556 mq->hstatus[0] = 0;
557 mq->hstatus[1] = 1;
558 mq->head = gru_mesq_head(2, qlines / 2 + 1);
559 mqd->mq = mq;
560 mqd->mq_gpa = uv_gpa(mq);
561 mqd->qlines = qlines;
562 mqd->interrupt_pnode = nasid >> 1;
563 mqd->interrupt_vector = vector;
564 mqd->interrupt_apicid = apicid;
565 return 0;
566 }
567 EXPORT_SYMBOL_GPL(gru_create_message_queue);
568
569 /*
570 * Send a NOOP message to a message queue
571 * Returns:
572 * 0 - if queue is full after the send. This is the normal case
573 * but various races can change this.
574 * -1 - if mesq sent successfully but queue not full
575 * >0 - unexpected error. MQE_xxx returned
576 */
send_noop_message(void * cb,struct gru_message_queue_desc * mqd,void * mesg)577 static int send_noop_message(void *cb, struct gru_message_queue_desc *mqd,
578 void *mesg)
579 {
580 const struct message_header noop_header = {
581 .present = MQS_NOOP, .lines = 1};
582 unsigned long m;
583 int substatus, ret;
584 struct message_header save_mhdr, *mhdr = mesg;
585
586 STAT(mesq_noop);
587 save_mhdr = *mhdr;
588 *mhdr = noop_header;
589 gru_mesq(cb, mqd->mq_gpa, gru_get_tri(mhdr), 1, IMA);
590 ret = gru_wait(cb);
591
592 if (ret) {
593 substatus = gru_get_cb_message_queue_substatus(cb);
594 switch (substatus) {
595 case CBSS_NO_ERROR:
596 STAT(mesq_noop_unexpected_error);
597 ret = MQE_UNEXPECTED_CB_ERR;
598 break;
599 case CBSS_LB_OVERFLOWED:
600 STAT(mesq_noop_lb_overflow);
601 ret = MQE_CONGESTION;
602 break;
603 case CBSS_QLIMIT_REACHED:
604 STAT(mesq_noop_qlimit_reached);
605 ret = 0;
606 break;
607 case CBSS_AMO_NACKED:
608 STAT(mesq_noop_amo_nacked);
609 ret = MQE_CONGESTION;
610 break;
611 case CBSS_PUT_NACKED:
612 STAT(mesq_noop_put_nacked);
613 m = mqd->mq_gpa + (gru_get_amo_value_head(cb) << 6);
614 gru_vstore(cb, m, gru_get_tri(mesg), XTYPE_CL, 1, 1,
615 IMA);
616 if (gru_wait(cb) == CBS_IDLE)
617 ret = MQIE_AGAIN;
618 else
619 ret = MQE_UNEXPECTED_CB_ERR;
620 break;
621 case CBSS_PAGE_OVERFLOW:
622 STAT(mesq_noop_page_overflow);
623 fallthrough;
624 default:
625 BUG();
626 }
627 }
628 *mhdr = save_mhdr;
629 return ret;
630 }
631
632 /*
633 * Handle a gru_mesq full.
634 */
send_message_queue_full(void * cb,struct gru_message_queue_desc * mqd,void * mesg,int lines)635 static int send_message_queue_full(void *cb, struct gru_message_queue_desc *mqd,
636 void *mesg, int lines)
637 {
638 union gru_mesqhead mqh;
639 unsigned int limit, head;
640 unsigned long avalue;
641 int half, qlines;
642
643 /* Determine if switching to first/second half of q */
644 avalue = gru_get_amo_value(cb);
645 head = gru_get_amo_value_head(cb);
646 limit = gru_get_amo_value_limit(cb);
647
648 qlines = mqd->qlines;
649 half = (limit != qlines);
650
651 if (half)
652 mqh = gru_mesq_head(qlines / 2 + 1, qlines);
653 else
654 mqh = gru_mesq_head(2, qlines / 2 + 1);
655
656 /* Try to get lock for switching head pointer */
657 gru_gamir(cb, EOP_IR_CLR, HSTATUS(mqd->mq_gpa, half), XTYPE_DW, IMA);
658 if (gru_wait(cb) != CBS_IDLE)
659 goto cberr;
660 if (!gru_get_amo_value(cb)) {
661 STAT(mesq_qf_locked);
662 return MQE_QUEUE_FULL;
663 }
664
665 /* Got the lock. Send optional NOP if queue not full, */
666 if (head != limit) {
667 if (send_noop_message(cb, mqd, mesg)) {
668 gru_gamir(cb, EOP_IR_INC, HSTATUS(mqd->mq_gpa, half),
669 XTYPE_DW, IMA);
670 if (gru_wait(cb) != CBS_IDLE)
671 goto cberr;
672 STAT(mesq_qf_noop_not_full);
673 return MQIE_AGAIN;
674 }
675 avalue++;
676 }
677
678 /* Then flip queuehead to other half of queue. */
679 gru_gamer(cb, EOP_ERR_CSWAP, mqd->mq_gpa, XTYPE_DW, mqh.val, avalue,
680 IMA);
681 if (gru_wait(cb) != CBS_IDLE)
682 goto cberr;
683
684 /* If not successfully in swapping queue head, clear the hstatus lock */
685 if (gru_get_amo_value(cb) != avalue) {
686 STAT(mesq_qf_switch_head_failed);
687 gru_gamir(cb, EOP_IR_INC, HSTATUS(mqd->mq_gpa, half), XTYPE_DW,
688 IMA);
689 if (gru_wait(cb) != CBS_IDLE)
690 goto cberr;
691 }
692 return MQIE_AGAIN;
693 cberr:
694 STAT(mesq_qf_unexpected_error);
695 return MQE_UNEXPECTED_CB_ERR;
696 }
697
698 /*
699 * Handle a PUT failure. Note: if message was a 2-line message, one of the
700 * lines might have successfully have been written. Before sending the
701 * message, "present" must be cleared in BOTH lines to prevent the receiver
702 * from prematurely seeing the full message.
703 */
send_message_put_nacked(void * cb,struct gru_message_queue_desc * mqd,void * mesg,int lines)704 static int send_message_put_nacked(void *cb, struct gru_message_queue_desc *mqd,
705 void *mesg, int lines)
706 {
707 unsigned long m;
708 int ret, loops = 200; /* experimentally determined */
709
710 m = mqd->mq_gpa + (gru_get_amo_value_head(cb) << 6);
711 if (lines == 2) {
712 gru_vset(cb, m, 0, XTYPE_CL, lines, 1, IMA);
713 if (gru_wait(cb) != CBS_IDLE)
714 return MQE_UNEXPECTED_CB_ERR;
715 }
716 gru_vstore(cb, m, gru_get_tri(mesg), XTYPE_CL, lines, 1, IMA);
717 if (gru_wait(cb) != CBS_IDLE)
718 return MQE_UNEXPECTED_CB_ERR;
719
720 if (!mqd->interrupt_vector)
721 return MQE_OK;
722
723 /*
724 * Send a noop message in order to deliver a cross-partition interrupt
725 * to the SSI that contains the target message queue. Normally, the
726 * interrupt is automatically delivered by hardware following mesq
727 * operations, but some error conditions require explicit delivery.
728 * The noop message will trigger delivery. Otherwise partition failures
729 * could cause unrecovered errors.
730 */
731 do {
732 ret = send_noop_message(cb, mqd, mesg);
733 } while ((ret == MQIE_AGAIN || ret == MQE_CONGESTION) && (loops-- > 0));
734
735 if (ret == MQIE_AGAIN || ret == MQE_CONGESTION) {
736 /*
737 * Don't indicate to the app to resend the message, as it's
738 * already been successfully sent. We simply send an OK
739 * (rather than fail the send with MQE_UNEXPECTED_CB_ERR),
740 * assuming that the other side is receiving enough
741 * interrupts to get this message processed anyway.
742 */
743 ret = MQE_OK;
744 }
745 return ret;
746 }
747
748 /*
749 * Handle a gru_mesq failure. Some of these failures are software recoverable
750 * or retryable.
751 */
send_message_failure(void * cb,struct gru_message_queue_desc * mqd,void * mesg,int lines)752 static int send_message_failure(void *cb, struct gru_message_queue_desc *mqd,
753 void *mesg, int lines)
754 {
755 int substatus, ret = 0;
756
757 substatus = gru_get_cb_message_queue_substatus(cb);
758 switch (substatus) {
759 case CBSS_NO_ERROR:
760 STAT(mesq_send_unexpected_error);
761 ret = MQE_UNEXPECTED_CB_ERR;
762 break;
763 case CBSS_LB_OVERFLOWED:
764 STAT(mesq_send_lb_overflow);
765 ret = MQE_CONGESTION;
766 break;
767 case CBSS_QLIMIT_REACHED:
768 STAT(mesq_send_qlimit_reached);
769 ret = send_message_queue_full(cb, mqd, mesg, lines);
770 break;
771 case CBSS_AMO_NACKED:
772 STAT(mesq_send_amo_nacked);
773 ret = MQE_CONGESTION;
774 break;
775 case CBSS_PUT_NACKED:
776 STAT(mesq_send_put_nacked);
777 ret = send_message_put_nacked(cb, mqd, mesg, lines);
778 break;
779 case CBSS_PAGE_OVERFLOW:
780 STAT(mesq_page_overflow);
781 fallthrough;
782 default:
783 BUG();
784 }
785 return ret;
786 }
787
788 /*
789 * Send a message to a message queue
790 * mqd message queue descriptor
791 * mesg message. ust be vaddr within a GSEG
792 * bytes message size (<= 2 CL)
793 */
gru_send_message_gpa(struct gru_message_queue_desc * mqd,void * mesg,unsigned int bytes)794 int gru_send_message_gpa(struct gru_message_queue_desc *mqd, void *mesg,
795 unsigned int bytes)
796 {
797 struct message_header *mhdr;
798 void *cb;
799 void *dsr;
800 int istatus, clines, ret;
801
802 STAT(mesq_send);
803 BUG_ON(bytes < sizeof(int) || bytes > 2 * GRU_CACHE_LINE_BYTES);
804
805 clines = DIV_ROUND_UP(bytes, GRU_CACHE_LINE_BYTES);
806 if (gru_get_cpu_resources(bytes, &cb, &dsr))
807 return MQE_BUG_NO_RESOURCES;
808 memcpy(dsr, mesg, bytes);
809 mhdr = dsr;
810 mhdr->present = MQS_FULL;
811 mhdr->lines = clines;
812 if (clines == 2) {
813 mhdr->present2 = get_present2(mhdr);
814 restore_present2(mhdr, MQS_FULL);
815 }
816
817 do {
818 ret = MQE_OK;
819 gru_mesq(cb, mqd->mq_gpa, gru_get_tri(mhdr), clines, IMA);
820 istatus = gru_wait(cb);
821 if (istatus != CBS_IDLE)
822 ret = send_message_failure(cb, mqd, dsr, clines);
823 } while (ret == MQIE_AGAIN);
824 gru_free_cpu_resources(cb, dsr);
825
826 if (ret)
827 STAT(mesq_send_failed);
828 return ret;
829 }
830 EXPORT_SYMBOL_GPL(gru_send_message_gpa);
831
832 /*
833 * Advance the receive pointer for the queue to the next message.
834 */
gru_free_message(struct gru_message_queue_desc * mqd,void * mesg)835 void gru_free_message(struct gru_message_queue_desc *mqd, void *mesg)
836 {
837 struct message_queue *mq = mqd->mq;
838 struct message_header *mhdr = mq->next;
839 void *next, *pnext;
840 int half = -1;
841 int lines = mhdr->lines;
842
843 if (lines == 2)
844 restore_present2(mhdr, MQS_EMPTY);
845 mhdr->present = MQS_EMPTY;
846
847 pnext = mq->next;
848 next = pnext + GRU_CACHE_LINE_BYTES * lines;
849 if (next == mq->limit) {
850 next = mq->start;
851 half = 1;
852 } else if (pnext < mq->start2 && next >= mq->start2) {
853 half = 0;
854 }
855
856 if (half >= 0)
857 mq->hstatus[half] = 1;
858 mq->next = next;
859 }
860 EXPORT_SYMBOL_GPL(gru_free_message);
861
862 /*
863 * Get next message from message queue. Return NULL if no message
864 * present. User must call next_message() to move to next message.
865 * rmq message queue
866 */
gru_get_next_message(struct gru_message_queue_desc * mqd)867 void *gru_get_next_message(struct gru_message_queue_desc *mqd)
868 {
869 struct message_queue *mq = mqd->mq;
870 struct message_header *mhdr = mq->next;
871 int present = mhdr->present;
872
873 /* skip NOOP messages */
874 while (present == MQS_NOOP) {
875 gru_free_message(mqd, mhdr);
876 mhdr = mq->next;
877 present = mhdr->present;
878 }
879
880 /* Wait for both halves of 2 line messages */
881 if (present == MQS_FULL && mhdr->lines == 2 &&
882 get_present2(mhdr) == MQS_EMPTY)
883 present = MQS_EMPTY;
884
885 if (!present) {
886 STAT(mesq_receive_none);
887 return NULL;
888 }
889
890 if (mhdr->lines == 2)
891 restore_present2(mhdr, mhdr->present2);
892
893 STAT(mesq_receive);
894 return mhdr;
895 }
896 EXPORT_SYMBOL_GPL(gru_get_next_message);
897
898 /* ---------------------- GRU DATA COPY FUNCTIONS ---------------------------*/
899
900 /*
901 * Load a DW from a global GPA. The GPA can be a memory or MMR address.
902 */
gru_read_gpa(unsigned long * value,unsigned long gpa)903 int gru_read_gpa(unsigned long *value, unsigned long gpa)
904 {
905 void *cb;
906 void *dsr;
907 int ret, iaa;
908
909 STAT(read_gpa);
910 if (gru_get_cpu_resources(GRU_NUM_KERNEL_DSR_BYTES, &cb, &dsr))
911 return MQE_BUG_NO_RESOURCES;
912 iaa = gpa >> 62;
913 gru_vload_phys(cb, gpa, gru_get_tri(dsr), iaa, IMA);
914 ret = gru_wait(cb);
915 if (ret == CBS_IDLE)
916 *value = *(unsigned long *)dsr;
917 gru_free_cpu_resources(cb, dsr);
918 return ret;
919 }
920 EXPORT_SYMBOL_GPL(gru_read_gpa);
921
922
923 /*
924 * Copy a block of data using the GRU resources
925 */
gru_copy_gpa(unsigned long dest_gpa,unsigned long src_gpa,unsigned int bytes)926 int gru_copy_gpa(unsigned long dest_gpa, unsigned long src_gpa,
927 unsigned int bytes)
928 {
929 void *cb;
930 void *dsr;
931 int ret;
932
933 STAT(copy_gpa);
934 if (gru_get_cpu_resources(GRU_NUM_KERNEL_DSR_BYTES, &cb, &dsr))
935 return MQE_BUG_NO_RESOURCES;
936 gru_bcopy(cb, src_gpa, dest_gpa, gru_get_tri(dsr),
937 XTYPE_B, bytes, GRU_NUM_KERNEL_DSR_CL, IMA);
938 ret = gru_wait(cb);
939 gru_free_cpu_resources(cb, dsr);
940 return ret;
941 }
942 EXPORT_SYMBOL_GPL(gru_copy_gpa);
943
944 /* ------------------- KERNEL QUICKTESTS RUN AT STARTUP ----------------*/
945 /* Temp - will delete after we gain confidence in the GRU */
946
quicktest0(unsigned long arg)947 static int quicktest0(unsigned long arg)
948 {
949 unsigned long word0;
950 unsigned long word1;
951 void *cb;
952 void *dsr;
953 unsigned long *p;
954 int ret = -EIO;
955
956 if (gru_get_cpu_resources(GRU_CACHE_LINE_BYTES, &cb, &dsr))
957 return MQE_BUG_NO_RESOURCES;
958 p = dsr;
959 word0 = MAGIC;
960 word1 = 0;
961
962 gru_vload(cb, uv_gpa(&word0), gru_get_tri(dsr), XTYPE_DW, 1, 1, IMA);
963 if (gru_wait(cb) != CBS_IDLE) {
964 printk(KERN_DEBUG "GRU:%d quicktest0: CBR failure 1\n", smp_processor_id());
965 goto done;
966 }
967
968 if (*p != MAGIC) {
969 printk(KERN_DEBUG "GRU:%d quicktest0 bad magic 0x%lx\n", smp_processor_id(), *p);
970 goto done;
971 }
972 gru_vstore(cb, uv_gpa(&word1), gru_get_tri(dsr), XTYPE_DW, 1, 1, IMA);
973 if (gru_wait(cb) != CBS_IDLE) {
974 printk(KERN_DEBUG "GRU:%d quicktest0: CBR failure 2\n", smp_processor_id());
975 goto done;
976 }
977
978 if (word0 != word1 || word1 != MAGIC) {
979 printk(KERN_DEBUG
980 "GRU:%d quicktest0 err: found 0x%lx, expected 0x%lx\n",
981 smp_processor_id(), word1, MAGIC);
982 goto done;
983 }
984 ret = 0;
985
986 done:
987 gru_free_cpu_resources(cb, dsr);
988 return ret;
989 }
990
991 #define ALIGNUP(p, q) ((void *)(((unsigned long)(p) + (q) - 1) & ~(q - 1)))
992
quicktest1(unsigned long arg)993 static int quicktest1(unsigned long arg)
994 {
995 struct gru_message_queue_desc mqd;
996 void *p, *mq;
997 int i, ret = -EIO;
998 char mes[GRU_CACHE_LINE_BYTES], *m;
999
1000 /* Need 1K cacheline aligned that does not cross page boundary */
1001 p = kmalloc(4096, 0);
1002 if (p == NULL)
1003 return -ENOMEM;
1004 mq = ALIGNUP(p, 1024);
1005 memset(mes, 0xee, sizeof(mes));
1006
1007 gru_create_message_queue(&mqd, mq, 8 * GRU_CACHE_LINE_BYTES, 0, 0, 0);
1008 for (i = 0; i < 6; i++) {
1009 mes[8] = i;
1010 do {
1011 ret = gru_send_message_gpa(&mqd, mes, sizeof(mes));
1012 } while (ret == MQE_CONGESTION);
1013 if (ret)
1014 break;
1015 }
1016 if (ret != MQE_QUEUE_FULL || i != 4) {
1017 printk(KERN_DEBUG "GRU:%d quicktest1: unexpected status %d, i %d\n",
1018 smp_processor_id(), ret, i);
1019 goto done;
1020 }
1021
1022 for (i = 0; i < 6; i++) {
1023 m = gru_get_next_message(&mqd);
1024 if (!m || m[8] != i)
1025 break;
1026 gru_free_message(&mqd, m);
1027 }
1028 if (i != 4) {
1029 printk(KERN_DEBUG "GRU:%d quicktest2: bad message, i %d, m %p, m8 %d\n",
1030 smp_processor_id(), i, m, m ? m[8] : -1);
1031 goto done;
1032 }
1033 ret = 0;
1034
1035 done:
1036 kfree(p);
1037 return ret;
1038 }
1039
quicktest2(unsigned long arg)1040 static int quicktest2(unsigned long arg)
1041 {
1042 static DECLARE_COMPLETION(cmp);
1043 unsigned long han;
1044 int blade_id = 0;
1045 int numcb = 4;
1046 int ret = 0;
1047 unsigned long *buf;
1048 void *cb0, *cb;
1049 struct gru_control_block_status *gen;
1050 int i, k, istatus, bytes;
1051
1052 bytes = numcb * 4 * 8;
1053 buf = kmalloc(bytes, GFP_KERNEL);
1054 if (!buf)
1055 return -ENOMEM;
1056
1057 ret = -EBUSY;
1058 han = gru_reserve_async_resources(blade_id, numcb, 0, &cmp);
1059 if (!han)
1060 goto done;
1061
1062 gru_lock_async_resource(han, &cb0, NULL);
1063 memset(buf, 0xee, bytes);
1064 for (i = 0; i < numcb; i++)
1065 gru_vset(cb0 + i * GRU_HANDLE_STRIDE, uv_gpa(&buf[i * 4]), 0,
1066 XTYPE_DW, 4, 1, IMA_INTERRUPT);
1067
1068 ret = 0;
1069 k = numcb;
1070 do {
1071 gru_wait_async_cbr(han);
1072 for (i = 0; i < numcb; i++) {
1073 cb = cb0 + i * GRU_HANDLE_STRIDE;
1074 istatus = gru_check_status(cb);
1075 if (istatus != CBS_ACTIVE && istatus != CBS_CALL_OS)
1076 break;
1077 }
1078 if (i == numcb)
1079 continue;
1080 if (istatus != CBS_IDLE) {
1081 printk(KERN_DEBUG "GRU:%d quicktest2: cb %d, exception\n", smp_processor_id(), i);
1082 ret = -EFAULT;
1083 } else if (buf[4 * i] || buf[4 * i + 1] || buf[4 * i + 2] ||
1084 buf[4 * i + 3]) {
1085 printk(KERN_DEBUG "GRU:%d quicktest2:cb %d, buf 0x%lx, 0x%lx, 0x%lx, 0x%lx\n",
1086 smp_processor_id(), i, buf[4 * i], buf[4 * i + 1], buf[4 * i + 2], buf[4 * i + 3]);
1087 ret = -EIO;
1088 }
1089 k--;
1090 gen = cb;
1091 gen->istatus = CBS_CALL_OS; /* don't handle this CBR again */
1092 } while (k);
1093 BUG_ON(cmp.done);
1094
1095 gru_unlock_async_resource(han);
1096 gru_release_async_resources(han);
1097 done:
1098 kfree(buf);
1099 return ret;
1100 }
1101
1102 #define BUFSIZE 200
quicktest3(unsigned long arg)1103 static int quicktest3(unsigned long arg)
1104 {
1105 char buf1[BUFSIZE], buf2[BUFSIZE];
1106 int ret = 0;
1107
1108 memset(buf2, 0, sizeof(buf2));
1109 memset(buf1, get_cycles() & 255, sizeof(buf1));
1110 gru_copy_gpa(uv_gpa(buf2), uv_gpa(buf1), BUFSIZE);
1111 if (memcmp(buf1, buf2, BUFSIZE)) {
1112 printk(KERN_DEBUG "GRU:%d quicktest3 error\n", smp_processor_id());
1113 ret = -EIO;
1114 }
1115 return ret;
1116 }
1117
1118 /*
1119 * Debugging only. User hook for various kernel tests
1120 * of driver & gru.
1121 */
gru_ktest(unsigned long arg)1122 int gru_ktest(unsigned long arg)
1123 {
1124 int ret = -EINVAL;
1125
1126 switch (arg & 0xff) {
1127 case 0:
1128 ret = quicktest0(arg);
1129 break;
1130 case 1:
1131 ret = quicktest1(arg);
1132 break;
1133 case 2:
1134 ret = quicktest2(arg);
1135 break;
1136 case 3:
1137 ret = quicktest3(arg);
1138 break;
1139 case 99:
1140 ret = gru_free_kernel_contexts();
1141 break;
1142 }
1143 return ret;
1144
1145 }
1146
gru_kservices_init(void)1147 int gru_kservices_init(void)
1148 {
1149 return 0;
1150 }
1151
gru_kservices_exit(void)1152 void gru_kservices_exit(void)
1153 {
1154 if (gru_free_kernel_contexts())
1155 BUG();
1156 }
1157
1158