2 * SN Platform GRU Driver
4 * KERNEL SERVICES THAT USE THE GRU
6 * Copyright (c) 2008 Silicon Graphics, Inc. All Rights Reserved.
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 #include <linux/kernel.h>
24 #include <linux/errno.h>
25 #include <linux/slab.h>
27 #include <linux/smp_lock.h>
28 #include <linux/spinlock.h>
29 #include <linux/device.h>
30 #include <linux/miscdevice.h>
31 #include <linux/proc_fs.h>
32 #include <linux/interrupt.h>
33 #include <linux/uaccess.h>
34 #include <linux/delay.h>
37 #include "grutables.h"
38 #include "grukservices.h"
39 #include "gru_instructions.h"
40 #include <asm/uv/uv_hub.h>
45 * The following is an interim algorithm for management of kernel GRU
46 * resources. This will likely be replaced when we better understand the
47 * kernel/user requirements.
49 * Blade percpu resources reserved for kernel use. These resources are
50 * reserved whenever the the kernel context for the blade is loaded. Note
51 * that the kernel context is not guaranteed to be always available. It is
52 * loaded on demand & can be stolen by a user if the user demand exceeds the
53 * kernel demand. The kernel can always reload the kernel context but
54 * a SLEEP may be required!!!.
56 #define GRU_NUM_KERNEL_CBR 1
57 #define GRU_NUM_KERNEL_DSR_BYTES 256
58 #define GRU_NUM_KERNEL_DSR_CL (GRU_NUM_KERNEL_DSR_BYTES / \
61 /* GRU instruction attributes for all instructions */
62 #define IMA IMA_CB_DELAY
64 /* GRU cacheline size is always 64 bytes - even on arches with 128 byte lines */
65 #define __gru_cacheline_aligned__ \
66 __attribute__((__aligned__(GRU_CACHE_LINE_BYTES)))
68 #define MAGIC 0x1234567887654321UL
70 /* Default retry count for GRU errors on kernel instructions */
71 #define EXCEPTION_RETRY_LIMIT 3
73 /* Status of message queue sections */
78 /*----------------- RESOURCE MANAGEMENT -------------------------------------*/
79 /* optimized for x86_64 */
80 struct message_queue
{
81 union gru_mesqhead head __gru_cacheline_aligned__
; /* CL 0 */
82 int qlines
; /* DW 1 */
84 void *next __gru_cacheline_aligned__
;/* CL 1 */
88 char data ____cacheline_aligned
; /* CL 2 */
91 /* First word in every message - used by mesq interface */
92 struct message_header
{
99 #define HSTATUS(mq, h) ((mq) + offsetof(struct message_queue, hstatus[h]))
102 * Allocate a kernel context (GTS) for the specified blade.
103 * - protected by writelock on bs_kgts_sema.
105 static void gru_alloc_kernel_context(struct gru_blade_state
*bs
, int blade_id
)
107 int cbr_au_count
, dsr_au_count
, ncpus
;
109 ncpus
= uv_blade_nr_possible_cpus(blade_id
);
110 cbr_au_count
= GRU_CB_COUNT_TO_AU(GRU_NUM_KERNEL_CBR
* ncpus
);
111 dsr_au_count
= GRU_DS_BYTES_TO_AU(GRU_NUM_KERNEL_DSR_BYTES
* ncpus
);
112 bs
->bs_kgts
= gru_alloc_gts(NULL
, cbr_au_count
, dsr_au_count
, 0, 0);
116 * Reload the blade's kernel context into a GRU chiplet. Called holding
117 * the bs_kgts_sema for READ. Will steal user contexts if necessary.
119 static void gru_load_kernel_context(struct gru_blade_state
*bs
, int blade_id
)
121 struct gru_state
*gru
;
122 struct gru_thread_state
*kgts
;
126 up_read(&bs
->bs_kgts_sema
);
127 down_write(&bs
->bs_kgts_sema
);
130 gru_alloc_kernel_context(bs
, blade_id
);
134 STAT(load_kernel_context
);
135 while (!gru_assign_gru_context(kgts
, blade_id
)) {
137 gru_steal_context(kgts
, blade_id
);
139 gru_load_context(kgts
);
140 gru
= bs
->bs_kgts
->ts_gru
;
141 vaddr
= gru
->gs_gru_base_vaddr
;
142 ctxnum
= kgts
->ts_ctxnum
;
143 bs
->kernel_cb
= get_gseg_base_address_cb(vaddr
, ctxnum
, 0);
144 bs
->kernel_dsr
= get_gseg_base_address_ds(vaddr
, ctxnum
, 0);
146 downgrade_write(&bs
->bs_kgts_sema
);
150 * Lock & load the kernel context for the specified blade.
152 static struct gru_blade_state
*gru_lock_kernel_context(int blade_id
)
154 struct gru_blade_state
*bs
;
156 STAT(lock_kernel_context
);
157 bs
= gru_base
[blade_id
];
159 down_read(&bs
->bs_kgts_sema
);
160 if (!bs
->bs_kgts
|| !bs
->bs_kgts
->ts_gru
)
161 gru_load_kernel_context(bs
, blade_id
);
167 * Unlock the kernel context for the specified blade. Context is not
168 * unloaded but may be stolen before next use.
170 static void gru_unlock_kernel_context(int blade_id
)
172 struct gru_blade_state
*bs
;
174 bs
= gru_base
[blade_id
];
175 up_read(&bs
->bs_kgts_sema
);
176 STAT(unlock_kernel_context
);
180 * Reserve & get pointers to the DSR/CBRs reserved for the current cpu.
181 * - returns with preemption disabled
183 static int gru_get_cpu_resources(int dsr_bytes
, void **cb
, void **dsr
)
185 struct gru_blade_state
*bs
;
188 BUG_ON(dsr_bytes
> GRU_NUM_KERNEL_DSR_BYTES
);
190 bs
= gru_lock_kernel_context(uv_numa_blade_id());
191 lcpu
= uv_blade_processor_id();
192 *cb
= bs
->kernel_cb
+ lcpu
* GRU_HANDLE_STRIDE
;
193 *dsr
= bs
->kernel_dsr
+ lcpu
* GRU_NUM_KERNEL_DSR_BYTES
;
198 * Free the current cpus reserved DSR/CBR resources.
200 static void gru_free_cpu_resources(void *cb
, void *dsr
)
202 gru_unlock_kernel_context(uv_numa_blade_id());
206 /*----------------------------------------------------------------------*/
207 int gru_get_cb_exception_detail(void *cb
,
208 struct control_block_extended_exc_detail
*excdet
)
210 struct gru_control_block_extended
*cbe
;
212 cbe
= get_cbe(GRUBASE(cb
), get_cb_number(cb
));
213 prefetchw(cbe
); /* Harmless on hardware, required for emulator */
214 excdet
->opc
= cbe
->opccpy
;
215 excdet
->exopc
= cbe
->exopccpy
;
216 excdet
->ecause
= cbe
->ecause
;
217 excdet
->exceptdet0
= cbe
->idef1upd
;
218 excdet
->exceptdet1
= cbe
->idef3upd
;
222 char *gru_get_cb_exception_detail_str(int ret
, void *cb
,
225 struct gru_control_block_status
*gen
= (void *)cb
;
226 struct control_block_extended_exc_detail excdet
;
228 if (ret
> 0 && gen
->istatus
== CBS_EXCEPTION
) {
229 gru_get_cb_exception_detail(cb
, &excdet
);
231 "GRU exception: cb %p, opc %d, exopc %d, ecause 0x%x,"
232 "excdet0 0x%lx, excdet1 0x%x",
233 gen
, excdet
.opc
, excdet
.exopc
, excdet
.ecause
,
234 excdet
.exceptdet0
, excdet
.exceptdet1
);
236 snprintf(buf
, size
, "No exception");
241 static int gru_wait_idle_or_exception(struct gru_control_block_status
*gen
)
243 while (gen
->istatus
>= CBS_ACTIVE
) {
250 static int gru_retry_exception(void *cb
)
252 struct gru_control_block_status
*gen
= (void *)cb
;
253 struct control_block_extended_exc_detail excdet
;
254 int retry
= EXCEPTION_RETRY_LIMIT
;
257 if (gru_get_cb_message_queue_substatus(cb
))
259 if (gru_wait_idle_or_exception(gen
) == CBS_IDLE
)
262 gru_get_cb_exception_detail(cb
, &excdet
);
263 if (excdet
.ecause
& ~EXCEPTION_RETRY_BITS
)
268 gru_flush_cache(gen
);
270 return CBS_EXCEPTION
;
273 int gru_check_status_proc(void *cb
)
275 struct gru_control_block_status
*gen
= (void *)cb
;
279 if (ret
!= CBS_EXCEPTION
)
281 return gru_retry_exception(cb
);
285 int gru_wait_proc(void *cb
)
287 struct gru_control_block_status
*gen
= (void *)cb
;
290 ret
= gru_wait_idle_or_exception(gen
);
291 if (ret
== CBS_EXCEPTION
)
292 ret
= gru_retry_exception(cb
);
297 void gru_abort(int ret
, void *cb
, char *str
)
299 char buf
[GRU_EXC_STR_SIZE
];
301 panic("GRU FATAL ERROR: %s - %s\n", str
,
302 gru_get_cb_exception_detail_str(ret
, cb
, buf
, sizeof(buf
)));
305 void gru_wait_abort_proc(void *cb
)
309 ret
= gru_wait_proc(cb
);
311 gru_abort(ret
, cb
, "gru_wait_abort");
315 /*------------------------------ MESSAGE QUEUES -----------------------------*/
317 /* Internal status . These are NOT returned to the user. */
318 #define MQIE_AGAIN -1 /* try again */
322 * Save/restore the "present" flag that is in the second line of 2-line
325 static inline int get_present2(void *p
)
327 struct message_header
*mhdr
= p
+ GRU_CACHE_LINE_BYTES
;
328 return mhdr
->present
;
331 static inline void restore_present2(void *p
, int val
)
333 struct message_header
*mhdr
= p
+ GRU_CACHE_LINE_BYTES
;
338 * Create a message queue.
339 * qlines - message queue size in cache lines. Includes 2-line header.
341 int gru_create_message_queue(struct gru_message_queue_desc
*mqd
,
342 void *p
, unsigned int bytes
, int nasid
, int vector
, int apicid
)
344 struct message_queue
*mq
= p
;
347 qlines
= bytes
/ GRU_CACHE_LINE_BYTES
- 2;
348 memset(mq
, 0, bytes
);
349 mq
->start
= &mq
->data
;
350 mq
->start2
= &mq
->data
+ (qlines
/ 2 - 1) * GRU_CACHE_LINE_BYTES
;
351 mq
->next
= &mq
->data
;
352 mq
->limit
= &mq
->data
+ (qlines
- 2) * GRU_CACHE_LINE_BYTES
;
356 mq
->head
= gru_mesq_head(2, qlines
/ 2 + 1);
358 mqd
->mq_gpa
= uv_gpa(mq
);
359 mqd
->qlines
= qlines
;
360 mqd
->interrupt_pnode
= UV_NASID_TO_PNODE(nasid
);
361 mqd
->interrupt_vector
= vector
;
362 mqd
->interrupt_apicid
= apicid
;
365 EXPORT_SYMBOL_GPL(gru_create_message_queue
);
368 * Send a NOOP message to a message queue
370 * 0 - if queue is full after the send. This is the normal case
371 * but various races can change this.
372 * -1 - if mesq sent successfully but queue not full
373 * >0 - unexpected error. MQE_xxx returned
375 static int send_noop_message(void *cb
, struct gru_message_queue_desc
*mqd
,
378 const struct message_header noop_header
= {
379 .present
= MQS_NOOP
, .lines
= 1};
382 struct message_header save_mhdr
, *mhdr
= mesg
;
387 gru_mesq(cb
, mqd
->mq_gpa
, gru_get_tri(mhdr
), 1, IMA
);
391 substatus
= gru_get_cb_message_queue_substatus(cb
);
394 STAT(mesq_noop_unexpected_error
);
395 ret
= MQE_UNEXPECTED_CB_ERR
;
397 case CBSS_LB_OVERFLOWED
:
398 STAT(mesq_noop_lb_overflow
);
399 ret
= MQE_CONGESTION
;
401 case CBSS_QLIMIT_REACHED
:
402 STAT(mesq_noop_qlimit_reached
);
405 case CBSS_AMO_NACKED
:
406 STAT(mesq_noop_amo_nacked
);
407 ret
= MQE_CONGESTION
;
409 case CBSS_PUT_NACKED
:
410 STAT(mesq_noop_put_nacked
);
411 m
= mqd
->mq_gpa
+ (gru_get_amo_value_head(cb
) << 6);
412 gru_vstore(cb
, m
, gru_get_tri(mesg
), XTYPE_CL
, 1, 1,
414 if (gru_wait(cb
) == CBS_IDLE
)
417 ret
= MQE_UNEXPECTED_CB_ERR
;
419 case CBSS_PAGE_OVERFLOW
:
429 * Handle a gru_mesq full.
431 static int send_message_queue_full(void *cb
, struct gru_message_queue_desc
*mqd
,
432 void *mesg
, int lines
)
434 union gru_mesqhead mqh
;
435 unsigned int limit
, head
;
436 unsigned long avalue
;
439 /* Determine if switching to first/second half of q */
440 avalue
= gru_get_amo_value(cb
);
441 head
= gru_get_amo_value_head(cb
);
442 limit
= gru_get_amo_value_limit(cb
);
444 qlines
= mqd
->qlines
;
445 half
= (limit
!= qlines
);
448 mqh
= gru_mesq_head(qlines
/ 2 + 1, qlines
);
450 mqh
= gru_mesq_head(2, qlines
/ 2 + 1);
452 /* Try to get lock for switching head pointer */
453 gru_gamir(cb
, EOP_IR_CLR
, HSTATUS(mqd
->mq_gpa
, half
), XTYPE_DW
, IMA
);
454 if (gru_wait(cb
) != CBS_IDLE
)
456 if (!gru_get_amo_value(cb
)) {
457 STAT(mesq_qf_locked
);
458 return MQE_QUEUE_FULL
;
461 /* Got the lock. Send optional NOP if queue not full, */
463 if (send_noop_message(cb
, mqd
, mesg
)) {
464 gru_gamir(cb
, EOP_IR_INC
, HSTATUS(mqd
->mq_gpa
, half
),
466 if (gru_wait(cb
) != CBS_IDLE
)
468 STAT(mesq_qf_noop_not_full
);
474 /* Then flip queuehead to other half of queue. */
475 gru_gamer(cb
, EOP_ERR_CSWAP
, mqd
->mq_gpa
, XTYPE_DW
, mqh
.val
, avalue
,
477 if (gru_wait(cb
) != CBS_IDLE
)
480 /* If not successfully in swapping queue head, clear the hstatus lock */
481 if (gru_get_amo_value(cb
) != avalue
) {
482 STAT(mesq_qf_switch_head_failed
);
483 gru_gamir(cb
, EOP_IR_INC
, HSTATUS(mqd
->mq_gpa
, half
), XTYPE_DW
,
485 if (gru_wait(cb
) != CBS_IDLE
)
490 STAT(mesq_qf_unexpected_error
);
491 return MQE_UNEXPECTED_CB_ERR
;
495 * Send a cross-partition interrupt to the SSI that contains the target
496 * message queue. Normally, the interrupt is automatically delivered by hardware
497 * but some error conditions require explicit delivery.
499 static void send_message_queue_interrupt(struct gru_message_queue_desc
*mqd
)
501 if (mqd
->interrupt_vector
)
502 uv_hub_send_ipi(mqd
->interrupt_pnode
, mqd
->interrupt_apicid
,
503 mqd
->interrupt_vector
);
507 * Handle a PUT failure. Note: if message was a 2-line message, one of the
508 * lines might have successfully have been written. Before sending the
509 * message, "present" must be cleared in BOTH lines to prevent the receiver
510 * from prematurely seeing the full message.
512 static int send_message_put_nacked(void *cb
, struct gru_message_queue_desc
*mqd
,
513 void *mesg
, int lines
)
517 m
= mqd
->mq_gpa
+ (gru_get_amo_value_head(cb
) << 6);
519 gru_vset(cb
, m
, 0, XTYPE_CL
, lines
, 1, IMA
);
520 if (gru_wait(cb
) != CBS_IDLE
)
521 return MQE_UNEXPECTED_CB_ERR
;
523 gru_vstore(cb
, m
, gru_get_tri(mesg
), XTYPE_CL
, lines
, 1, IMA
);
524 if (gru_wait(cb
) != CBS_IDLE
)
525 return MQE_UNEXPECTED_CB_ERR
;
526 send_message_queue_interrupt(mqd
);
531 * Handle a gru_mesq failure. Some of these failures are software recoverable
534 static int send_message_failure(void *cb
, struct gru_message_queue_desc
*mqd
,
535 void *mesg
, int lines
)
537 int substatus
, ret
= 0;
539 substatus
= gru_get_cb_message_queue_substatus(cb
);
542 STAT(mesq_send_unexpected_error
);
543 ret
= MQE_UNEXPECTED_CB_ERR
;
545 case CBSS_LB_OVERFLOWED
:
546 STAT(mesq_send_lb_overflow
);
547 ret
= MQE_CONGESTION
;
549 case CBSS_QLIMIT_REACHED
:
550 STAT(mesq_send_qlimit_reached
);
551 ret
= send_message_queue_full(cb
, mqd
, mesg
, lines
);
553 case CBSS_AMO_NACKED
:
554 STAT(mesq_send_amo_nacked
);
555 ret
= MQE_CONGESTION
;
557 case CBSS_PUT_NACKED
:
558 STAT(mesq_send_put_nacked
);
559 ret
= send_message_put_nacked(cb
, mqd
, mesg
, lines
);
568 * Send a message to a message queue
569 * mqd message queue descriptor
570 * mesg message. ust be vaddr within a GSEG
571 * bytes message size (<= 2 CL)
573 int gru_send_message_gpa(struct gru_message_queue_desc
*mqd
, void *mesg
,
576 struct message_header
*mhdr
;
579 int istatus
, clines
, ret
;
582 BUG_ON(bytes
< sizeof(int) || bytes
> 2 * GRU_CACHE_LINE_BYTES
);
584 clines
= DIV_ROUND_UP(bytes
, GRU_CACHE_LINE_BYTES
);
585 if (gru_get_cpu_resources(bytes
, &cb
, &dsr
))
586 return MQE_BUG_NO_RESOURCES
;
587 memcpy(dsr
, mesg
, bytes
);
589 mhdr
->present
= MQS_FULL
;
590 mhdr
->lines
= clines
;
592 mhdr
->present2
= get_present2(mhdr
);
593 restore_present2(mhdr
, MQS_FULL
);
598 gru_mesq(cb
, mqd
->mq_gpa
, gru_get_tri(mhdr
), clines
, IMA
);
599 istatus
= gru_wait(cb
);
600 if (istatus
!= CBS_IDLE
)
601 ret
= send_message_failure(cb
, mqd
, dsr
, clines
);
602 } while (ret
== MQIE_AGAIN
);
603 gru_free_cpu_resources(cb
, dsr
);
606 STAT(mesq_send_failed
);
609 EXPORT_SYMBOL_GPL(gru_send_message_gpa
);
612 * Advance the receive pointer for the queue to the next message.
614 void gru_free_message(struct gru_message_queue_desc
*mqd
, void *mesg
)
616 struct message_queue
*mq
= mqd
->mq
;
617 struct message_header
*mhdr
= mq
->next
;
620 int lines
= mhdr
->lines
;
623 restore_present2(mhdr
, MQS_EMPTY
);
624 mhdr
->present
= MQS_EMPTY
;
627 next
= pnext
+ GRU_CACHE_LINE_BYTES
* lines
;
628 if (next
== mq
->limit
) {
631 } else if (pnext
< mq
->start2
&& next
>= mq
->start2
) {
636 mq
->hstatus
[half
] = 1;
639 EXPORT_SYMBOL_GPL(gru_free_message
);
642 * Get next message from message queue. Return NULL if no message
643 * present. User must call next_message() to move to next message.
646 void *gru_get_next_message(struct gru_message_queue_desc
*mqd
)
648 struct message_queue
*mq
= mqd
->mq
;
649 struct message_header
*mhdr
= mq
->next
;
650 int present
= mhdr
->present
;
652 /* skip NOOP messages */
654 while (present
== MQS_NOOP
) {
655 gru_free_message(mqd
, mhdr
);
657 present
= mhdr
->present
;
660 /* Wait for both halves of 2 line messages */
661 if (present
== MQS_FULL
&& mhdr
->lines
== 2 &&
662 get_present2(mhdr
) == MQS_EMPTY
)
666 STAT(mesq_receive_none
);
670 if (mhdr
->lines
== 2)
671 restore_present2(mhdr
, mhdr
->present2
);
675 EXPORT_SYMBOL_GPL(gru_get_next_message
);
677 /* ---------------------- GRU DATA COPY FUNCTIONS ---------------------------*/
680 * Copy a block of data using the GRU resources
682 int gru_copy_gpa(unsigned long dest_gpa
, unsigned long src_gpa
,
690 if (gru_get_cpu_resources(GRU_NUM_KERNEL_DSR_BYTES
, &cb
, &dsr
))
691 return MQE_BUG_NO_RESOURCES
;
692 gru_bcopy(cb
, src_gpa
, dest_gpa
, gru_get_tri(dsr
),
693 XTYPE_B
, bytes
, GRU_NUM_KERNEL_DSR_CL
, IMA
);
695 gru_free_cpu_resources(cb
, dsr
);
698 EXPORT_SYMBOL_GPL(gru_copy_gpa
);
700 /* ------------------- KERNEL QUICKTESTS RUN AT STARTUP ----------------*/
701 /* Temp - will delete after we gain confidence in the GRU */
711 if (gru_get_cpu_resources(GRU_CACHE_LINE_BYTES
, &cb
, &dsr
))
712 return MQE_BUG_NO_RESOURCES
;
717 gru_vload(cb
, uv_gpa(&word0
), gru_get_tri(dsr
), XTYPE_DW
, 1, 1, IMA
);
718 if (gru_wait(cb
) != CBS_IDLE
)
723 gru_vstore(cb
, uv_gpa(&word1
), gru_get_tri(dsr
), XTYPE_DW
, 1, 1, IMA
);
724 if (gru_wait(cb
) != CBS_IDLE
)
726 gru_free_cpu_resources(cb
, dsr
);
728 if (word0
!= word1
|| word1
!= MAGIC
) {
730 ("GRU quicktest err: found 0x%lx, expected 0x%lx\n",
732 BUG(); /* ZZZ should not be fatal */
739 int gru_kservices_init(struct gru_state
*gru
)
741 struct gru_blade_state
*bs
;
744 if (gru
!= &bs
->bs_grus
[0])
747 init_rwsem(&bs
->bs_kgts_sema
);
749 if (gru_options
& GRU_QUICKLOOK
)
754 void gru_kservices_exit(struct gru_state
*gru
)
756 struct gru_blade_state
*bs
;
757 struct gru_thread_state
*kgts
;
760 if (gru
!= &bs
->bs_grus
[0])
764 if (kgts
&& kgts
->ts_gru
)
765 gru_unload_context(kgts
, 0);