summaryrefslogtreecommitdiff
path: root/drivers/misc/sgi-gru/grukservices.c
blob: 880c55dfb66266dfd53cae3dea2492b986ff5744 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
/*
 * SN Platform GRU Driver
 *
 *              KERNEL SERVICES THAT USE THE GRU
 *
 *  Copyright (c) 2008 Silicon Graphics, Inc.  All Rights Reserved.
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 */

#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/smp_lock.h>
#include <linux/spinlock.h>
#include <linux/device.h>
#include <linux/miscdevice.h>
#include <linux/proc_fs.h>
#include <linux/interrupt.h>
#include <linux/uaccess.h>
#include "gru.h"
#include "grulib.h"
#include "grutables.h"
#include "grukservices.h"
#include "gru_instructions.h"
#include <asm/uv/uv_hub.h>

/*
 * Kernel GRU Usage
 *
 * The following is an interim algorithm for management of kernel GRU
 * resources. This will likely be replaced when we better understand the
 * kernel/user requirements.
 *
 * At boot time, the kernel permanently reserves a fixed number of
 * CBRs/DSRs for each cpu to use. The resources are all taken from
 * the GRU chiplet 1 on the blade. This leaves the full set of resources
 * of chiplet 0 available to be allocated to a single user.
 */

/* Blade percpu resources PERMANENTLY reserved for kernel use */
#define GRU_NUM_KERNEL_CBR      1
#define GRU_NUM_KERNEL_DSR_BYTES 256
#define KERNEL_CTXNUM           15

/* GRU instruction attributes for all instructions */
#define IMA			IMA_CB_DELAY

/* GRU cacheline size is always 64 bytes - even on arches with 128 byte lines */
#define __gru_cacheline_aligned__                               \
	__attribute__((__aligned__(GRU_CACHE_LINE_BYTES)))

#define MAGIC	0x1234567887654321UL

/* Default retry count for GRU errors on kernel instructions */
#define EXCEPTION_RETRY_LIMIT	3

/* Status of message queue sections */
#define MQS_EMPTY		0
#define MQS_FULL		1
#define MQS_NOOP		2

/*----------------- RESOURCE MANAGEMENT -------------------------------------*/
/* optimized for x86_64 */
struct message_queue {
	union gru_mesqhead	head __gru_cacheline_aligned__;	/* CL 0 */
	int			qlines;				/* DW 1 */
	long 			hstatus[2];
	void 			*next __gru_cacheline_aligned__;/* CL 1 */
	void 			*limit;
	void 			*start;
	void 			*start2;
	char			data ____cacheline_aligned;	/* CL 2 */
};

/* First word in every message - used by mesq interface */
struct message_header {
	char	present;
	char	present2;
	char 	lines;
	char	fill;
};

#define QLINES(mq)	((mq) + offsetof(struct message_queue, qlines))
#define HSTATUS(mq, h)	((mq) + offsetof(struct message_queue, hstatus[h]))

static int gru_get_cpu_resources(int dsr_bytes, void **cb, void **dsr)
{
	struct gru_blade_state *bs;
	int lcpu;

	BUG_ON(dsr_bytes > GRU_NUM_KERNEL_DSR_BYTES);
	preempt_disable();
	bs = gru_base[uv_numa_blade_id()];
	lcpu = uv_blade_processor_id();
	*cb = bs->kernel_cb + lcpu * GRU_HANDLE_STRIDE;
	*dsr = bs->kernel_dsr + lcpu * GRU_NUM_KERNEL_DSR_BYTES;
	return 0;
}

static void gru_free_cpu_resources(void *cb, void *dsr)
{
	preempt_enable();
}

int gru_get_cb_exception_detail(void *cb,
		struct control_block_extended_exc_detail *excdet)
{
	struct gru_control_block_extended *cbe;

	cbe = get_cbe(GRUBASE(cb), get_cb_number(cb));
	prefetchw(cbe);         /* Harmless on hardware, required for emulator */
	excdet->opc = cbe->opccpy;
	excdet->exopc = cbe->exopccpy;
	excdet->ecause = cbe->ecause;
	excdet->exceptdet0 = cbe->idef1upd;
	excdet->exceptdet1 = cbe->idef3upd;
	return 0;
}

char *gru_get_cb_exception_detail_str(int ret, void *cb,
				      char *buf, int size)
{
	struct gru_control_block_status *gen = (void *)cb;
	struct control_block_extended_exc_detail excdet;

	if (ret > 0 && gen->istatus == CBS_EXCEPTION) {
		gru_get_cb_exception_detail(cb, &excdet);
		snprintf(buf, size,
			"GRU exception: cb %p, opc %d, exopc %d, ecause 0x%x,"
			"excdet0 0x%lx, excdet1 0x%x",
			gen, excdet.opc, excdet.exopc, excdet.ecause,
			excdet.exceptdet0, excdet.exceptdet1);
	} else {
		snprintf(buf, size, "No exception");
	}
	return buf;
}

static int gru_wait_idle_or_exception(struct gru_control_block_status *gen)
{
	while (gen->istatus >= CBS_ACTIVE) {
		cpu_relax();
		barrier();
	}
	return gen->istatus;
}

static int gru_retry_exception(void *cb)
{
	struct gru_control_block_status *gen = (void *)cb;
	struct control_block_extended_exc_detail excdet;
	int retry = EXCEPTION_RETRY_LIMIT;

	while (1)  {
		if (gru_get_cb_message_queue_substatus(cb))
			break;
		if (gru_wait_idle_or_exception(gen) == CBS_IDLE)
			return CBS_IDLE;

		gru_get_cb_exception_detail(cb, &excdet);
		if (excdet.ecause & ~EXCEPTION_RETRY_BITS)
			break;
		if (retry-- == 0)
			break;
		gen->icmd = 1;
		gru_flush_cache(gen);
	}
	return CBS_EXCEPTION;
}

int gru_check_status_proc(void *cb)
{
	struct gru_control_block_status *gen = (void *)cb;
	int ret;

	ret = gen->istatus;
	if (ret != CBS_EXCEPTION)
		return ret;
	return gru_retry_exception(cb);

}

int gru_wait_proc(void *cb)
{
	struct gru_control_block_status *gen = (void *)cb;
	int ret;

	ret = gru_wait_idle_or_exception(gen);
	if (ret == CBS_EXCEPTION)
		ret = gru_retry_exception(cb);

	return ret;
}

void gru_abort(int ret, void *cb, char *str)
{
	char buf[GRU_EXC_STR_SIZE];

	panic("GRU FATAL ERROR: %s - %s\n", str,
	      gru_get_cb_exception_detail_str(ret, cb, buf, sizeof(buf)));
}

void gru_wait_abort_proc(void *cb)
{
	int ret;

	ret = gru_wait_proc(cb);
	if (ret)
		gru_abort(ret, cb, "gru_wait_abort");
}


/*------------------------------ MESSAGE QUEUES -----------------------------*/

/* Internal status . These are NOT returned to the user. */
#define MQIE_AGAIN		-1	/* try again */


/*
 * Save/restore the "present" flag that is in the second line of 2-line
 * messages
 */
static inline int get_present2(void *p)
{
	struct message_header *mhdr = p + GRU_CACHE_LINE_BYTES;
	return mhdr->present;
}

static inline void restore_present2(void *p, int val)
{
	struct message_header *mhdr = p + GRU_CACHE_LINE_BYTES;
	mhdr->present = val;
}

/*
 * Create a message queue.
 * 	qlines - message queue size in cache lines. Includes 2-line header.
 */
int gru_create_message_queue(void *p, unsigned int bytes)
{
	struct message_queue *mq = p;
	unsigned int qlines;

	qlines = bytes / GRU_CACHE_LINE_BYTES - 2;
	memset(mq, 0, bytes);
	mq->start = &mq->data;
	mq->start2 = &mq->data + (qlines / 2 - 1) * GRU_CACHE_LINE_BYTES;
	mq->next = &mq->data;
	mq->limit = &mq->data + (qlines - 2) * GRU_CACHE_LINE_BYTES;
	mq->qlines = qlines;
	mq->hstatus[0] = 0;
	mq->hstatus[1] = 1;
	mq->head = gru_mesq_head(2, qlines / 2 + 1);
	return 0;
}
EXPORT_SYMBOL_GPL(gru_create_message_queue);

/*
 * Send a NOOP message to a message queue
 * 	Returns:
 * 		 0 - if queue is full after the send. This is the normal case
 * 		     but various races can change this.
 *		-1 - if mesq sent successfully but queue not full
 *		>0 - unexpected error. MQE_xxx returned
 */
static int send_noop_message(void *cb,
				unsigned long mq, void *mesg)
{
	const struct message_header noop_header = {
					.present = MQS_NOOP, .lines = 1};
	unsigned long m;
	int substatus, ret;
	struct message_header save_mhdr, *mhdr = mesg;

	STAT(mesq_noop);
	save_mhdr = *mhdr;
	*mhdr = noop_header;
	gru_mesq(cb, mq, gru_get_tri(mhdr), 1, IMA);
	ret = gru_wait(cb);

	if (ret) {
		substatus = gru_get_cb_message_queue_substatus(cb);
		switch (substatus) {
		case CBSS_NO_ERROR:
			STAT(mesq_noop_unexpected_error);
			ret = MQE_UNEXPECTED_CB_ERR;
			break;
		case CBSS_LB_OVERFLOWED:
			STAT(mesq_noop_lb_overflow);
			ret = MQE_CONGESTION;
			break;
		case CBSS_QLIMIT_REACHED:
			STAT(mesq_noop_qlimit_reached);
			ret = 0;
			break;
		case CBSS_AMO_NACKED:
			STAT(mesq_noop_amo_nacked);
			ret = MQE_CONGESTION;
			break;
		case CBSS_PUT_NACKED:
			STAT(mesq_noop_put_nacked);
			m = mq + (gru_get_amo_value_head(cb) << 6);
			gru_vstore(cb, m, gru_get_tri(mesg), XTYPE_CL, 1, 1,
						IMA);
			if (gru_wait(cb) == CBS_IDLE)
				ret = MQIE_AGAIN;
			else
				ret = MQE_UNEXPECTED_CB_ERR;
			break;
		case CBSS_PAGE_OVERFLOW:
		default:
			BUG();
		}
	}
	*mhdr = save_mhdr;
	return ret;
}

/*
 * Handle a gru_mesq full.
 */
static int send_message_queue_full(void *cb,
			   unsigned long mq, void *mesg, int lines)
{
	union gru_mesqhead mqh;
	unsigned int limit, head;
	unsigned long avalue;
	int half, qlines, save;

	/* Determine if switching to first/second half of q */
	avalue = gru_get_amo_value(cb);
	head = gru_get_amo_value_head(cb);
	limit = gru_get_amo_value_limit(cb);

	/*
	 * Fetch "qlines" from the queue header. Since the queue may be
	 * in memory that can't be accessed using socket addresses, use
	 * the GRU to access the data. Use DSR space from the message.
	 */
	save = *(int *)mesg;
	gru_vload(cb, QLINES(mq), gru_get_tri(mesg), XTYPE_W, 1, 1, IMA);
	if (gru_wait(cb) != CBS_IDLE)
		goto cberr;
	qlines = *(int *)mesg;
	*(int *)mesg = save;
	half = (limit != qlines);

	if (half)
		mqh = gru_mesq_head(qlines / 2 + 1, qlines);
	else
		mqh = gru_mesq_head(2, qlines / 2 + 1);

	/* Try to get lock for switching head pointer */
	gru_gamir(cb, EOP_IR_CLR, HSTATUS(mq, half), XTYPE_DW, IMA);
	if (gru_wait(cb) != CBS_IDLE)
		goto cberr;
	if (!gru_get_amo_value(cb)) {
		STAT(mesq_qf_locked);
		return MQE_QUEUE_FULL;
	}

	/* Got the lock. Send optional NOP if queue not full, */
	if (head != limit) {
		if (send_noop_message(cb, mq, mesg)) {
			gru_gamir(cb, EOP_IR_INC, HSTATUS(mq, half),
					XTYPE_DW, IMA);
			if (gru_wait(cb) != CBS_IDLE)
				goto cberr;
			STAT(mesq_qf_noop_not_full);
			return MQIE_AGAIN;
		}
		avalue++;
	}

	/* Then flip queuehead to other half of queue. */
	gru_gamer(cb, EOP_ERR_CSWAP, mq, XTYPE_DW, mqh.val, avalue, IMA);
	if (gru_wait(cb) != CBS_IDLE)
		goto cberr;

	/* If not successfully in swapping queue head, clear the hstatus lock */
	if (gru_get_amo_value(cb) != avalue) {
		STAT(mesq_qf_switch_head_failed);
		gru_gamir(cb, EOP_IR_INC, HSTATUS(mq, half), XTYPE_DW, IMA);
		if (gru_wait(cb) != CBS_IDLE)
			goto cberr;
	}
	return MQIE_AGAIN;
cberr:
	STAT(mesq_qf_unexpected_error);
	return MQE_UNEXPECTED_CB_ERR;
}


/*
 * Handle a gru_mesq failure. Some of these failures are software recoverable
 * or retryable.
 */
static int send_message_failure(void *cb,
				unsigned long mq,
				void *mesg,
				int lines)
{
	int substatus, ret = 0;
	unsigned long m;

	substatus = gru_get_cb_message_queue_substatus(cb);
	switch (substatus) {
	case CBSS_NO_ERROR:
		STAT(mesq_send_unexpected_error);
		ret = MQE_UNEXPECTED_CB_ERR;
		break;
	case CBSS_LB_OVERFLOWED:
		STAT(mesq_send_lb_overflow);
		ret = MQE_CONGESTION;
		break;
	case CBSS_QLIMIT_REACHED:
		STAT(mesq_send_qlimit_reached);
		ret = send_message_queue_full(cb, mq, mesg, lines);
		break;
	case CBSS_AMO_NACKED:
		STAT(mesq_send_amo_nacked);
		ret = MQE_CONGESTION;
		break;
	case CBSS_PUT_NACKED:
		STAT(mesq_send_put_nacked);
		m =mq + (gru_get_amo_value_head(cb) << 6);
		gru_vstore(cb, m, gru_get_tri(mesg), XTYPE_CL, lines, 1, IMA);
		if (gru_wait(cb) == CBS_IDLE)
			ret = MQE_OK;
		else
			ret = MQE_UNEXPECTED_CB_ERR;
		break;
	default:
		BUG();
	}
	return ret;
}

/*
 * Send a message to a message queue
 * 	cb	GRU control block to use to send message
 * 	mq	message queue
 * 	mesg	message. ust be vaddr within a GSEG
 * 	bytes	message size (<= 2 CL)
 */
int gru_send_message_gpa(unsigned long mq, void *mesg, unsigned int bytes)
{
	struct message_header *mhdr;
	void *cb;
	void *dsr;
	int istatus, clines, ret;

	STAT(mesq_send);
	BUG_ON(bytes < sizeof(int) || bytes > 2 * GRU_CACHE_LINE_BYTES);

	clines = DIV_ROUND_UP(bytes, GRU_CACHE_LINE_BYTES);
	if (gru_get_cpu_resources(bytes, &cb, &dsr))
		return MQE_BUG_NO_RESOURCES;
	memcpy(dsr, mesg, bytes);
	mhdr = dsr;
	mhdr->present = MQS_FULL;
	mhdr->lines = clines;
	if (clines == 2) {
		mhdr->present2 = get_present2(mhdr);
		restore_present2(mhdr, MQS_FULL);
	}

	do {
		ret = MQE_OK;
		gru_mesq(cb, mq, gru_get_tri(mhdr), clines, IMA);
		istatus = gru_wait(cb);
		if (istatus != CBS_IDLE)
			ret = send_message_failure(cb, mq, dsr, clines);
	} while (ret == MQIE_AGAIN);
	gru_free_cpu_resources(cb, dsr);

	if (ret)
		STAT(mesq_send_failed);
	return ret;
}
EXPORT_SYMBOL_GPL(gru_send_message_gpa);

/*
 * Advance the receive pointer for the queue to the next message.
 */
void gru_free_message(void *rmq, void *mesg)
{
	struct message_queue *mq = rmq;
	struct message_header *mhdr = mq->next;
	void *next, *pnext;
	int half = -1;
	int lines = mhdr->lines;

	if (lines == 2)
		restore_present2(mhdr, MQS_EMPTY);
	mhdr->present = MQS_EMPTY;

	pnext = mq->next;
	next = pnext + GRU_CACHE_LINE_BYTES * lines;
	if (next == mq->limit) {
		next = mq->start;
		half = 1;
	} else if (pnext < mq->start2 && next >= mq->start2) {
		half = 0;
	}

	if (half >= 0)
		mq->hstatus[half] = 1;
	mq->next = next;
}
EXPORT_SYMBOL_GPL(gru_free_message);

/*
 * Get next message from message queue. Return NULL if no message
 * present. User must call next_message() to move to next message.
 * 	rmq	message queue
 */
void *gru_get_next_message(void *rmq)
{
	struct message_queue *mq = rmq;
	struct message_header *mhdr = mq->next;
	int present = mhdr->present;

	/* skip NOOP messages */
	STAT(mesq_receive);
	while (present == MQS_NOOP) {
		gru_free_message(rmq, mhdr);
		mhdr = mq->next;
		present = mhdr->present;
	}

	/* Wait for both halves of 2 line messages */
	if (present == MQS_FULL && mhdr->lines == 2 &&
				get_present2(mhdr) == MQS_EMPTY)
		present = MQS_EMPTY;

	if (!present) {
		STAT(mesq_receive_none);
		return NULL;
	}

	if (mhdr->lines == 2)
		restore_present2(mhdr, mhdr->present2);

	return mhdr;
}
EXPORT_SYMBOL_GPL(gru_get_next_message);

/* ---------------------- GRU DATA COPY FUNCTIONS ---------------------------*/

/*
 * Copy a block of data using the GRU resources
 */
int gru_copy_gpa(unsigned long dest_gpa, unsigned long src_gpa,
				unsigned int bytes)
{
	void *cb;
	void *dsr;
	int ret;

	STAT(copy_gpa);
	if (gru_get_cpu_resources(GRU_NUM_KERNEL_DSR_BYTES, &cb, &dsr))
		return MQE_BUG_NO_RESOURCES;
	gru_bcopy(cb, src_gpa, dest_gpa, gru_get_tri(dsr),
		  XTYPE_B, bytes, GRU_NUM_KERNEL_DSR_BYTES, IMA);
	ret = gru_wait(cb);
	gru_free_cpu_resources(cb, dsr);
	return ret;
}
EXPORT_SYMBOL_GPL(gru_copy_gpa);

/* ------------------- KERNEL QUICKTESTS RUN AT STARTUP ----------------*/
/* 	Temp - will delete after we gain confidence in the GRU		*/
static __cacheline_aligned unsigned long word0;
static __cacheline_aligned unsigned long word1;

static int quicktest(struct gru_state *gru)
{
	void *cb;
	void *ds;
	unsigned long *p;

	cb = get_gseg_base_address_cb(gru->gs_gru_base_vaddr, KERNEL_CTXNUM, 0);
	ds = get_gseg_base_address_ds(gru->gs_gru_base_vaddr, KERNEL_CTXNUM, 0);
	p = ds;
	word0 = MAGIC;

	gru_vload(cb, uv_gpa(&word0), 0, XTYPE_DW, 1, 1, IMA);
	if (gru_wait(cb) != CBS_IDLE)
		BUG();

	if (*(unsigned long *)ds != MAGIC)
		BUG();
	gru_vstore(cb, uv_gpa(&word1), 0, XTYPE_DW, 1, 1, IMA);
	if (gru_wait(cb) != CBS_IDLE)
		BUG();

	if (word0 != word1 || word0 != MAGIC) {
		printk
		    ("GRU quicktest err: gru %d, found 0x%lx, expected 0x%lx\n",
		     gru->gs_gid, word1, MAGIC);
		BUG();		/* ZZZ should not be fatal */
	}

	return 0;
}


int gru_kservices_init(struct gru_state *gru)
{
	struct gru_blade_state *bs;
	struct gru_context_configuration_handle *cch;
	unsigned long cbr_map, dsr_map;
	int err, num, cpus_possible;

	/*
	 * Currently, resources are reserved ONLY on the second chiplet
	 * on each blade. This leaves ALL resources on chiplet 0 available
	 * for user code.
	 */
	bs = gru->gs_blade;
	if (gru != &bs->bs_grus[1])
		return 0;

	cpus_possible = uv_blade_nr_possible_cpus(gru->gs_blade_id);

	num = GRU_NUM_KERNEL_CBR * cpus_possible;
	cbr_map = gru_reserve_cb_resources(gru, GRU_CB_COUNT_TO_AU(num), NULL);
	gru->gs_reserved_cbrs += num;

	num = GRU_NUM_KERNEL_DSR_BYTES * cpus_possible;
	dsr_map = gru_reserve_ds_resources(gru, GRU_DS_BYTES_TO_AU(num), NULL);
	gru->gs_reserved_dsr_bytes += num;

	gru->gs_active_contexts++;
	__set_bit(KERNEL_CTXNUM, &gru->gs_context_map);
	cch = get_cch(gru->gs_gru_base_vaddr, KERNEL_CTXNUM);

	bs->kernel_cb = get_gseg_base_address_cb(gru->gs_gru_base_vaddr,
					KERNEL_CTXNUM, 0);
	bs->kernel_dsr = get_gseg_base_address_ds(gru->gs_gru_base_vaddr,
					KERNEL_CTXNUM, 0);

	lock_cch_handle(cch);
	cch->tfm_fault_bit_enable = 0;
	cch->tlb_int_enable = 0;
	cch->tfm_done_bit_enable = 0;
	cch->unmap_enable = 1;
	err = cch_allocate(cch, 0, cbr_map, dsr_map);
	if (err) {
		gru_dbg(grudev,
			"Unable to allocate kernel CCH: gru %d, err %d\n",
			gru->gs_gid, err);
		BUG();
	}
	if (cch_start(cch)) {
		gru_dbg(grudev, "Unable to start kernel CCH: gru %d, err %d\n",
			gru->gs_gid, err);
		BUG();
	}
	unlock_cch_handle(cch);

	if (gru_options & GRU_QUICKLOOK)
		quicktest(gru);
	return 0;
}