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1 /*
2  * Copyright(c) 2015-2018 Intel Corporation.
3  *
4  * This file is provided under a dual BSD/GPLv2 license.  When using or
5  * redistributing this file, you may do so under either license.
6  *
7  * GPL LICENSE SUMMARY
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of version 2 of the GNU General Public License as
11  * published by the Free Software Foundation.
12  *
13  * This program is distributed in the hope that it will be useful, but
14  * WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16  * General Public License for more details.
17  *
18  * BSD LICENSE
19  *
20  * Redistribution and use in source and binary forms, with or without
21  * modification, are permitted provided that the following conditions
22  * are met:
23  *
24  *  - Redistributions of source code must retain the above copyright
25  *    notice, this list of conditions and the following disclaimer.
26  *  - Redistributions in binary form must reproduce the above copyright
27  *    notice, this list of conditions and the following disclaimer in
28  *    the documentation and/or other materials provided with the
29  *    distribution.
30  *  - Neither the name of Intel Corporation nor the names of its
31  *    contributors may be used to endorse or promote products derived
32  *    from this software without specific prior written permission.
33  *
34  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
35  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
36  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
37  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
38  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
39  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
40  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
41  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
42  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
43  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
44  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
45  *
46  */
47 
48 #include <linux/delay.h>
49 #include "hfi.h"
50 #include "qp.h"
51 #include "trace.h"
52 
53 #define SC(name) SEND_CTXT_##name
54 /*
55  * Send Context functions
56  */
57 static void sc_wait_for_packet_egress(struct send_context *sc, int pause);
58 
59 /*
60  * Set the CM reset bit and wait for it to clear.  Use the provided
61  * sendctrl register.  This routine has no locking.
62  */
__cm_reset(struct hfi1_devdata * dd,u64 sendctrl)63 void __cm_reset(struct hfi1_devdata *dd, u64 sendctrl)
64 {
65 	write_csr(dd, SEND_CTRL, sendctrl | SEND_CTRL_CM_RESET_SMASK);
66 	while (1) {
67 		udelay(1);
68 		sendctrl = read_csr(dd, SEND_CTRL);
69 		if ((sendctrl & SEND_CTRL_CM_RESET_SMASK) == 0)
70 			break;
71 	}
72 }
73 
74 /* global control of PIO send */
pio_send_control(struct hfi1_devdata * dd,int op)75 void pio_send_control(struct hfi1_devdata *dd, int op)
76 {
77 	u64 reg, mask;
78 	unsigned long flags;
79 	int write = 1;	/* write sendctrl back */
80 	int flush = 0;	/* re-read sendctrl to make sure it is flushed */
81 	int i;
82 
83 	spin_lock_irqsave(&dd->sendctrl_lock, flags);
84 
85 	reg = read_csr(dd, SEND_CTRL);
86 	switch (op) {
87 	case PSC_GLOBAL_ENABLE:
88 		reg |= SEND_CTRL_SEND_ENABLE_SMASK;
89 		fallthrough;
90 	case PSC_DATA_VL_ENABLE:
91 		mask = 0;
92 		for (i = 0; i < ARRAY_SIZE(dd->vld); i++)
93 			if (!dd->vld[i].mtu)
94 				mask |= BIT_ULL(i);
95 		/* Disallow sending on VLs not enabled */
96 		mask = (mask & SEND_CTRL_UNSUPPORTED_VL_MASK) <<
97 			SEND_CTRL_UNSUPPORTED_VL_SHIFT;
98 		reg = (reg & ~SEND_CTRL_UNSUPPORTED_VL_SMASK) | mask;
99 		break;
100 	case PSC_GLOBAL_DISABLE:
101 		reg &= ~SEND_CTRL_SEND_ENABLE_SMASK;
102 		break;
103 	case PSC_GLOBAL_VLARB_ENABLE:
104 		reg |= SEND_CTRL_VL_ARBITER_ENABLE_SMASK;
105 		break;
106 	case PSC_GLOBAL_VLARB_DISABLE:
107 		reg &= ~SEND_CTRL_VL_ARBITER_ENABLE_SMASK;
108 		break;
109 	case PSC_CM_RESET:
110 		__cm_reset(dd, reg);
111 		write = 0; /* CSR already written (and flushed) */
112 		break;
113 	case PSC_DATA_VL_DISABLE:
114 		reg |= SEND_CTRL_UNSUPPORTED_VL_SMASK;
115 		flush = 1;
116 		break;
117 	default:
118 		dd_dev_err(dd, "%s: invalid control %d\n", __func__, op);
119 		break;
120 	}
121 
122 	if (write) {
123 		write_csr(dd, SEND_CTRL, reg);
124 		if (flush)
125 			(void)read_csr(dd, SEND_CTRL); /* flush write */
126 	}
127 
128 	spin_unlock_irqrestore(&dd->sendctrl_lock, flags);
129 }
130 
131 /* number of send context memory pools */
132 #define NUM_SC_POOLS 2
133 
134 /* Send Context Size (SCS) wildcards */
135 #define SCS_POOL_0 -1
136 #define SCS_POOL_1 -2
137 
138 /* Send Context Count (SCC) wildcards */
139 #define SCC_PER_VL -1
140 #define SCC_PER_CPU  -2
141 #define SCC_PER_KRCVQ  -3
142 
143 /* Send Context Size (SCS) constants */
144 #define SCS_ACK_CREDITS  32
145 #define SCS_VL15_CREDITS 102	/* 3 pkts of 2048B data + 128B header */
146 
147 #define PIO_THRESHOLD_CEILING 4096
148 
149 #define PIO_WAIT_BATCH_SIZE 5
150 
151 /* default send context sizes */
152 static struct sc_config_sizes sc_config_sizes[SC_MAX] = {
153 	[SC_KERNEL] = { .size  = SCS_POOL_0,	/* even divide, pool 0 */
154 			.count = SCC_PER_VL },	/* one per NUMA */
155 	[SC_ACK]    = { .size  = SCS_ACK_CREDITS,
156 			.count = SCC_PER_KRCVQ },
157 	[SC_USER]   = { .size  = SCS_POOL_0,	/* even divide, pool 0 */
158 			.count = SCC_PER_CPU },	/* one per CPU */
159 	[SC_VL15]   = { .size  = SCS_VL15_CREDITS,
160 			.count = 1 },
161 
162 };
163 
164 /* send context memory pool configuration */
165 struct mem_pool_config {
166 	int centipercent;	/* % of memory, in 100ths of 1% */
167 	int absolute_blocks;	/* absolute block count */
168 };
169 
170 /* default memory pool configuration: 100% in pool 0 */
171 static struct mem_pool_config sc_mem_pool_config[NUM_SC_POOLS] = {
172 	/* centi%, abs blocks */
173 	{  10000,     -1 },		/* pool 0 */
174 	{      0,     -1 },		/* pool 1 */
175 };
176 
177 /* memory pool information, used when calculating final sizes */
178 struct mem_pool_info {
179 	int centipercent;	/*
180 				 * 100th of 1% of memory to use, -1 if blocks
181 				 * already set
182 				 */
183 	int count;		/* count of contexts in the pool */
184 	int blocks;		/* block size of the pool */
185 	int size;		/* context size, in blocks */
186 };
187 
188 /*
189  * Convert a pool wildcard to a valid pool index.  The wildcards
190  * start at -1 and increase negatively.  Map them as:
191  *	-1 => 0
192  *	-2 => 1
193  *	etc.
194  *
195  * Return -1 on non-wildcard input, otherwise convert to a pool number.
196  */
wildcard_to_pool(int wc)197 static int wildcard_to_pool(int wc)
198 {
199 	if (wc >= 0)
200 		return -1;	/* non-wildcard */
201 	return -wc - 1;
202 }
203 
204 static const char *sc_type_names[SC_MAX] = {
205 	"kernel",
206 	"ack",
207 	"user",
208 	"vl15"
209 };
210 
sc_type_name(int index)211 static const char *sc_type_name(int index)
212 {
213 	if (index < 0 || index >= SC_MAX)
214 		return "unknown";
215 	return sc_type_names[index];
216 }
217 
218 /*
219  * Read the send context memory pool configuration and send context
220  * size configuration.  Replace any wildcards and come up with final
221  * counts and sizes for the send context types.
222  */
init_sc_pools_and_sizes(struct hfi1_devdata * dd)223 int init_sc_pools_and_sizes(struct hfi1_devdata *dd)
224 {
225 	struct mem_pool_info mem_pool_info[NUM_SC_POOLS] = { { 0 } };
226 	int total_blocks = (chip_pio_mem_size(dd) / PIO_BLOCK_SIZE) - 1;
227 	int total_contexts = 0;
228 	int fixed_blocks;
229 	int pool_blocks;
230 	int used_blocks;
231 	int cp_total;		/* centipercent total */
232 	int ab_total;		/* absolute block total */
233 	int extra;
234 	int i;
235 
236 	/*
237 	 * When SDMA is enabled, kernel context pio packet size is capped by
238 	 * "piothreshold". Reduce pio buffer allocation for kernel context by
239 	 * setting it to a fixed size. The allocation allows 3-deep buffering
240 	 * of the largest pio packets plus up to 128 bytes header, sufficient
241 	 * to maintain verbs performance.
242 	 *
243 	 * When SDMA is disabled, keep the default pooling allocation.
244 	 */
245 	if (HFI1_CAP_IS_KSET(SDMA)) {
246 		u16 max_pkt_size = (piothreshold < PIO_THRESHOLD_CEILING) ?
247 					 piothreshold : PIO_THRESHOLD_CEILING;
248 		sc_config_sizes[SC_KERNEL].size =
249 			3 * (max_pkt_size + 128) / PIO_BLOCK_SIZE;
250 	}
251 
252 	/*
253 	 * Step 0:
254 	 *	- copy the centipercents/absolute sizes from the pool config
255 	 *	- sanity check these values
256 	 *	- add up centipercents, then later check for full value
257 	 *	- add up absolute blocks, then later check for over-commit
258 	 */
259 	cp_total = 0;
260 	ab_total = 0;
261 	for (i = 0; i < NUM_SC_POOLS; i++) {
262 		int cp = sc_mem_pool_config[i].centipercent;
263 		int ab = sc_mem_pool_config[i].absolute_blocks;
264 
265 		/*
266 		 * A negative value is "unused" or "invalid".  Both *can*
267 		 * be valid, but centipercent wins, so check that first
268 		 */
269 		if (cp >= 0) {			/* centipercent valid */
270 			cp_total += cp;
271 		} else if (ab >= 0) {		/* absolute blocks valid */
272 			ab_total += ab;
273 		} else {			/* neither valid */
274 			dd_dev_err(
275 				dd,
276 				"Send context memory pool %d: both the block count and centipercent are invalid\n",
277 				i);
278 			return -EINVAL;
279 		}
280 
281 		mem_pool_info[i].centipercent = cp;
282 		mem_pool_info[i].blocks = ab;
283 	}
284 
285 	/* do not use both % and absolute blocks for different pools */
286 	if (cp_total != 0 && ab_total != 0) {
287 		dd_dev_err(
288 			dd,
289 			"All send context memory pools must be described as either centipercent or blocks, no mixing between pools\n");
290 		return -EINVAL;
291 	}
292 
293 	/* if any percentages are present, they must add up to 100% x 100 */
294 	if (cp_total != 0 && cp_total != 10000) {
295 		dd_dev_err(
296 			dd,
297 			"Send context memory pool centipercent is %d, expecting 10000\n",
298 			cp_total);
299 		return -EINVAL;
300 	}
301 
302 	/* the absolute pool total cannot be more than the mem total */
303 	if (ab_total > total_blocks) {
304 		dd_dev_err(
305 			dd,
306 			"Send context memory pool absolute block count %d is larger than the memory size %d\n",
307 			ab_total, total_blocks);
308 		return -EINVAL;
309 	}
310 
311 	/*
312 	 * Step 2:
313 	 *	- copy from the context size config
314 	 *	- replace context type wildcard counts with real values
315 	 *	- add up non-memory pool block sizes
316 	 *	- add up memory pool user counts
317 	 */
318 	fixed_blocks = 0;
319 	for (i = 0; i < SC_MAX; i++) {
320 		int count = sc_config_sizes[i].count;
321 		int size = sc_config_sizes[i].size;
322 		int pool;
323 
324 		/*
325 		 * Sanity check count: Either a positive value or
326 		 * one of the expected wildcards is valid.  The positive
327 		 * value is checked later when we compare against total
328 		 * memory available.
329 		 */
330 		if (i == SC_ACK) {
331 			count = dd->n_krcv_queues;
332 		} else if (i == SC_KERNEL) {
333 			count = INIT_SC_PER_VL * num_vls;
334 		} else if (count == SCC_PER_CPU) {
335 			count = dd->num_rcv_contexts - dd->n_krcv_queues;
336 		} else if (count < 0) {
337 			dd_dev_err(
338 				dd,
339 				"%s send context invalid count wildcard %d\n",
340 				sc_type_name(i), count);
341 			return -EINVAL;
342 		}
343 		if (total_contexts + count > chip_send_contexts(dd))
344 			count = chip_send_contexts(dd) - total_contexts;
345 
346 		total_contexts += count;
347 
348 		/*
349 		 * Sanity check pool: The conversion will return a pool
350 		 * number or -1 if a fixed (non-negative) value.  The fixed
351 		 * value is checked later when we compare against
352 		 * total memory available.
353 		 */
354 		pool = wildcard_to_pool(size);
355 		if (pool == -1) {			/* non-wildcard */
356 			fixed_blocks += size * count;
357 		} else if (pool < NUM_SC_POOLS) {	/* valid wildcard */
358 			mem_pool_info[pool].count += count;
359 		} else {				/* invalid wildcard */
360 			dd_dev_err(
361 				dd,
362 				"%s send context invalid pool wildcard %d\n",
363 				sc_type_name(i), size);
364 			return -EINVAL;
365 		}
366 
367 		dd->sc_sizes[i].count = count;
368 		dd->sc_sizes[i].size = size;
369 	}
370 	if (fixed_blocks > total_blocks) {
371 		dd_dev_err(
372 			dd,
373 			"Send context fixed block count, %u, larger than total block count %u\n",
374 			fixed_blocks, total_blocks);
375 		return -EINVAL;
376 	}
377 
378 	/* step 3: calculate the blocks in the pools, and pool context sizes */
379 	pool_blocks = total_blocks - fixed_blocks;
380 	if (ab_total > pool_blocks) {
381 		dd_dev_err(
382 			dd,
383 			"Send context fixed pool sizes, %u, larger than pool block count %u\n",
384 			ab_total, pool_blocks);
385 		return -EINVAL;
386 	}
387 	/* subtract off the fixed pool blocks */
388 	pool_blocks -= ab_total;
389 
390 	for (i = 0; i < NUM_SC_POOLS; i++) {
391 		struct mem_pool_info *pi = &mem_pool_info[i];
392 
393 		/* % beats absolute blocks */
394 		if (pi->centipercent >= 0)
395 			pi->blocks = (pool_blocks * pi->centipercent) / 10000;
396 
397 		if (pi->blocks == 0 && pi->count != 0) {
398 			dd_dev_err(
399 				dd,
400 				"Send context memory pool %d has %u contexts, but no blocks\n",
401 				i, pi->count);
402 			return -EINVAL;
403 		}
404 		if (pi->count == 0) {
405 			/* warn about wasted blocks */
406 			if (pi->blocks != 0)
407 				dd_dev_err(
408 					dd,
409 					"Send context memory pool %d has %u blocks, but zero contexts\n",
410 					i, pi->blocks);
411 			pi->size = 0;
412 		} else {
413 			pi->size = pi->blocks / pi->count;
414 		}
415 	}
416 
417 	/* step 4: fill in the context type sizes from the pool sizes */
418 	used_blocks = 0;
419 	for (i = 0; i < SC_MAX; i++) {
420 		if (dd->sc_sizes[i].size < 0) {
421 			unsigned pool = wildcard_to_pool(dd->sc_sizes[i].size);
422 
423 			WARN_ON_ONCE(pool >= NUM_SC_POOLS);
424 			dd->sc_sizes[i].size = mem_pool_info[pool].size;
425 		}
426 		/* make sure we are not larger than what is allowed by the HW */
427 #define PIO_MAX_BLOCKS 1024
428 		if (dd->sc_sizes[i].size > PIO_MAX_BLOCKS)
429 			dd->sc_sizes[i].size = PIO_MAX_BLOCKS;
430 
431 		/* calculate our total usage */
432 		used_blocks += dd->sc_sizes[i].size * dd->sc_sizes[i].count;
433 	}
434 	extra = total_blocks - used_blocks;
435 	if (extra != 0)
436 		dd_dev_info(dd, "unused send context blocks: %d\n", extra);
437 
438 	return total_contexts;
439 }
440 
init_send_contexts(struct hfi1_devdata * dd)441 int init_send_contexts(struct hfi1_devdata *dd)
442 {
443 	u16 base;
444 	int ret, i, j, context;
445 
446 	ret = init_credit_return(dd);
447 	if (ret)
448 		return ret;
449 
450 	dd->hw_to_sw = kmalloc_array(TXE_NUM_CONTEXTS, sizeof(u8),
451 					GFP_KERNEL);
452 	dd->send_contexts = kcalloc(dd->num_send_contexts,
453 				    sizeof(struct send_context_info),
454 				    GFP_KERNEL);
455 	if (!dd->send_contexts || !dd->hw_to_sw) {
456 		kfree(dd->hw_to_sw);
457 		kfree(dd->send_contexts);
458 		free_credit_return(dd);
459 		return -ENOMEM;
460 	}
461 
462 	/* hardware context map starts with invalid send context indices */
463 	for (i = 0; i < TXE_NUM_CONTEXTS; i++)
464 		dd->hw_to_sw[i] = INVALID_SCI;
465 
466 	/*
467 	 * All send contexts have their credit sizes.  Allocate credits
468 	 * for each context one after another from the global space.
469 	 */
470 	context = 0;
471 	base = 1;
472 	for (i = 0; i < SC_MAX; i++) {
473 		struct sc_config_sizes *scs = &dd->sc_sizes[i];
474 
475 		for (j = 0; j < scs->count; j++) {
476 			struct send_context_info *sci =
477 						&dd->send_contexts[context];
478 			sci->type = i;
479 			sci->base = base;
480 			sci->credits = scs->size;
481 
482 			context++;
483 			base += scs->size;
484 		}
485 	}
486 
487 	return 0;
488 }
489 
490 /*
491  * Allocate a software index and hardware context of the given type.
492  *
493  * Must be called with dd->sc_lock held.
494  */
sc_hw_alloc(struct hfi1_devdata * dd,int type,u32 * sw_index,u32 * hw_context)495 static int sc_hw_alloc(struct hfi1_devdata *dd, int type, u32 *sw_index,
496 		       u32 *hw_context)
497 {
498 	struct send_context_info *sci;
499 	u32 index;
500 	u32 context;
501 
502 	for (index = 0, sci = &dd->send_contexts[0];
503 			index < dd->num_send_contexts; index++, sci++) {
504 		if (sci->type == type && sci->allocated == 0) {
505 			sci->allocated = 1;
506 			/* use a 1:1 mapping, but make them non-equal */
507 			context = chip_send_contexts(dd) - index - 1;
508 			dd->hw_to_sw[context] = index;
509 			*sw_index = index;
510 			*hw_context = context;
511 			return 0; /* success */
512 		}
513 	}
514 	dd_dev_err(dd, "Unable to locate a free type %d send context\n", type);
515 	return -ENOSPC;
516 }
517 
518 /*
519  * Free the send context given by its software index.
520  *
521  * Must be called with dd->sc_lock held.
522  */
sc_hw_free(struct hfi1_devdata * dd,u32 sw_index,u32 hw_context)523 static void sc_hw_free(struct hfi1_devdata *dd, u32 sw_index, u32 hw_context)
524 {
525 	struct send_context_info *sci;
526 
527 	sci = &dd->send_contexts[sw_index];
528 	if (!sci->allocated) {
529 		dd_dev_err(dd, "%s: sw_index %u not allocated? hw_context %u\n",
530 			   __func__, sw_index, hw_context);
531 	}
532 	sci->allocated = 0;
533 	dd->hw_to_sw[hw_context] = INVALID_SCI;
534 }
535 
536 /* return the base context of a context in a group */
group_context(u32 context,u32 group)537 static inline u32 group_context(u32 context, u32 group)
538 {
539 	return (context >> group) << group;
540 }
541 
542 /* return the size of a group */
group_size(u32 group)543 static inline u32 group_size(u32 group)
544 {
545 	return 1 << group;
546 }
547 
548 /*
549  * Obtain the credit return addresses, kernel virtual and bus, for the
550  * given sc.
551  *
552  * To understand this routine:
553  * o va and dma are arrays of struct credit_return.  One for each physical
554  *   send context, per NUMA.
555  * o Each send context always looks in its relative location in a struct
556  *   credit_return for its credit return.
557  * o Each send context in a group must have its return address CSR programmed
558  *   with the same value.  Use the address of the first send context in the
559  *   group.
560  */
cr_group_addresses(struct send_context * sc,dma_addr_t * dma)561 static void cr_group_addresses(struct send_context *sc, dma_addr_t *dma)
562 {
563 	u32 gc = group_context(sc->hw_context, sc->group);
564 	u32 index = sc->hw_context & 0x7;
565 
566 	sc->hw_free = &sc->dd->cr_base[sc->node].va[gc].cr[index];
567 	*dma = (unsigned long)
568 	       &((struct credit_return *)sc->dd->cr_base[sc->node].dma)[gc];
569 }
570 
571 /*
572  * Work queue function triggered in error interrupt routine for
573  * kernel contexts.
574  */
sc_halted(struct work_struct * work)575 static void sc_halted(struct work_struct *work)
576 {
577 	struct send_context *sc;
578 
579 	sc = container_of(work, struct send_context, halt_work);
580 	sc_restart(sc);
581 }
582 
583 /*
584  * Calculate PIO block threshold for this send context using the given MTU.
585  * Trigger a return when one MTU plus optional header of credits remain.
586  *
587  * Parameter mtu is in bytes.
588  * Parameter hdrqentsize is in DWORDs.
589  *
590  * Return value is what to write into the CSR: trigger return when
591  * unreturned credits pass this count.
592  */
sc_mtu_to_threshold(struct send_context * sc,u32 mtu,u32 hdrqentsize)593 u32 sc_mtu_to_threshold(struct send_context *sc, u32 mtu, u32 hdrqentsize)
594 {
595 	u32 release_credits;
596 	u32 threshold;
597 
598 	/* add in the header size, then divide by the PIO block size */
599 	mtu += hdrqentsize << 2;
600 	release_credits = DIV_ROUND_UP(mtu, PIO_BLOCK_SIZE);
601 
602 	/* check against this context's credits */
603 	if (sc->credits <= release_credits)
604 		threshold = 1;
605 	else
606 		threshold = sc->credits - release_credits;
607 
608 	return threshold;
609 }
610 
611 /*
612  * Calculate credit threshold in terms of percent of the allocated credits.
613  * Trigger when unreturned credits equal or exceed the percentage of the whole.
614  *
615  * Return value is what to write into the CSR: trigger return when
616  * unreturned credits pass this count.
617  */
sc_percent_to_threshold(struct send_context * sc,u32 percent)618 u32 sc_percent_to_threshold(struct send_context *sc, u32 percent)
619 {
620 	return (sc->credits * percent) / 100;
621 }
622 
623 /*
624  * Set the credit return threshold.
625  */
sc_set_cr_threshold(struct send_context * sc,u32 new_threshold)626 void sc_set_cr_threshold(struct send_context *sc, u32 new_threshold)
627 {
628 	unsigned long flags;
629 	u32 old_threshold;
630 	int force_return = 0;
631 
632 	spin_lock_irqsave(&sc->credit_ctrl_lock, flags);
633 
634 	old_threshold = (sc->credit_ctrl >>
635 				SC(CREDIT_CTRL_THRESHOLD_SHIFT))
636 			 & SC(CREDIT_CTRL_THRESHOLD_MASK);
637 
638 	if (new_threshold != old_threshold) {
639 		sc->credit_ctrl =
640 			(sc->credit_ctrl
641 				& ~SC(CREDIT_CTRL_THRESHOLD_SMASK))
642 			| ((new_threshold
643 				& SC(CREDIT_CTRL_THRESHOLD_MASK))
644 			   << SC(CREDIT_CTRL_THRESHOLD_SHIFT));
645 		write_kctxt_csr(sc->dd, sc->hw_context,
646 				SC(CREDIT_CTRL), sc->credit_ctrl);
647 
648 		/* force a credit return on change to avoid a possible stall */
649 		force_return = 1;
650 	}
651 
652 	spin_unlock_irqrestore(&sc->credit_ctrl_lock, flags);
653 
654 	if (force_return)
655 		sc_return_credits(sc);
656 }
657 
658 /*
659  * set_pio_integrity
660  *
661  * Set the CHECK_ENABLE register for the send context 'sc'.
662  */
set_pio_integrity(struct send_context * sc)663 void set_pio_integrity(struct send_context *sc)
664 {
665 	struct hfi1_devdata *dd = sc->dd;
666 	u32 hw_context = sc->hw_context;
667 	int type = sc->type;
668 
669 	write_kctxt_csr(dd, hw_context,
670 			SC(CHECK_ENABLE),
671 			hfi1_pkt_default_send_ctxt_mask(dd, type));
672 }
673 
get_buffers_allocated(struct send_context * sc)674 static u32 get_buffers_allocated(struct send_context *sc)
675 {
676 	int cpu;
677 	u32 ret = 0;
678 
679 	for_each_possible_cpu(cpu)
680 		ret += *per_cpu_ptr(sc->buffers_allocated, cpu);
681 	return ret;
682 }
683 
reset_buffers_allocated(struct send_context * sc)684 static void reset_buffers_allocated(struct send_context *sc)
685 {
686 	int cpu;
687 
688 	for_each_possible_cpu(cpu)
689 		(*per_cpu_ptr(sc->buffers_allocated, cpu)) = 0;
690 }
691 
692 /*
693  * Allocate a NUMA relative send context structure of the given type along
694  * with a HW context.
695  */
sc_alloc(struct hfi1_devdata * dd,int type,uint hdrqentsize,int numa)696 struct send_context *sc_alloc(struct hfi1_devdata *dd, int type,
697 			      uint hdrqentsize, int numa)
698 {
699 	struct send_context_info *sci;
700 	struct send_context *sc = NULL;
701 	dma_addr_t dma;
702 	unsigned long flags;
703 	u64 reg;
704 	u32 thresh;
705 	u32 sw_index;
706 	u32 hw_context;
707 	int ret;
708 	u8 opval, opmask;
709 
710 	/* do not allocate while frozen */
711 	if (dd->flags & HFI1_FROZEN)
712 		return NULL;
713 
714 	sc = kzalloc_node(sizeof(*sc), GFP_KERNEL, numa);
715 	if (!sc)
716 		return NULL;
717 
718 	sc->buffers_allocated = alloc_percpu(u32);
719 	if (!sc->buffers_allocated) {
720 		kfree(sc);
721 		dd_dev_err(dd,
722 			   "Cannot allocate buffers_allocated per cpu counters\n"
723 			  );
724 		return NULL;
725 	}
726 
727 	spin_lock_irqsave(&dd->sc_lock, flags);
728 	ret = sc_hw_alloc(dd, type, &sw_index, &hw_context);
729 	if (ret) {
730 		spin_unlock_irqrestore(&dd->sc_lock, flags);
731 		free_percpu(sc->buffers_allocated);
732 		kfree(sc);
733 		return NULL;
734 	}
735 
736 	sci = &dd->send_contexts[sw_index];
737 	sci->sc = sc;
738 
739 	sc->dd = dd;
740 	sc->node = numa;
741 	sc->type = type;
742 	spin_lock_init(&sc->alloc_lock);
743 	spin_lock_init(&sc->release_lock);
744 	spin_lock_init(&sc->credit_ctrl_lock);
745 	seqlock_init(&sc->waitlock);
746 	INIT_LIST_HEAD(&sc->piowait);
747 	INIT_WORK(&sc->halt_work, sc_halted);
748 	init_waitqueue_head(&sc->halt_wait);
749 
750 	/* grouping is always single context for now */
751 	sc->group = 0;
752 
753 	sc->sw_index = sw_index;
754 	sc->hw_context = hw_context;
755 	cr_group_addresses(sc, &dma);
756 	sc->credits = sci->credits;
757 	sc->size = sc->credits * PIO_BLOCK_SIZE;
758 
759 /* PIO Send Memory Address details */
760 #define PIO_ADDR_CONTEXT_MASK 0xfful
761 #define PIO_ADDR_CONTEXT_SHIFT 16
762 	sc->base_addr = dd->piobase + ((hw_context & PIO_ADDR_CONTEXT_MASK)
763 					<< PIO_ADDR_CONTEXT_SHIFT);
764 
765 	/* set base and credits */
766 	reg = ((sci->credits & SC(CTRL_CTXT_DEPTH_MASK))
767 					<< SC(CTRL_CTXT_DEPTH_SHIFT))
768 		| ((sci->base & SC(CTRL_CTXT_BASE_MASK))
769 					<< SC(CTRL_CTXT_BASE_SHIFT));
770 	write_kctxt_csr(dd, hw_context, SC(CTRL), reg);
771 
772 	set_pio_integrity(sc);
773 
774 	/* unmask all errors */
775 	write_kctxt_csr(dd, hw_context, SC(ERR_MASK), (u64)-1);
776 
777 	/* set the default partition key */
778 	write_kctxt_csr(dd, hw_context, SC(CHECK_PARTITION_KEY),
779 			(SC(CHECK_PARTITION_KEY_VALUE_MASK) &
780 			 DEFAULT_PKEY) <<
781 			SC(CHECK_PARTITION_KEY_VALUE_SHIFT));
782 
783 	/* per context type checks */
784 	if (type == SC_USER) {
785 		opval = USER_OPCODE_CHECK_VAL;
786 		opmask = USER_OPCODE_CHECK_MASK;
787 	} else {
788 		opval = OPCODE_CHECK_VAL_DISABLED;
789 		opmask = OPCODE_CHECK_MASK_DISABLED;
790 	}
791 
792 	/* set the send context check opcode mask and value */
793 	write_kctxt_csr(dd, hw_context, SC(CHECK_OPCODE),
794 			((u64)opmask << SC(CHECK_OPCODE_MASK_SHIFT)) |
795 			((u64)opval << SC(CHECK_OPCODE_VALUE_SHIFT)));
796 
797 	/* set up credit return */
798 	reg = dma & SC(CREDIT_RETURN_ADDR_ADDRESS_SMASK);
799 	write_kctxt_csr(dd, hw_context, SC(CREDIT_RETURN_ADDR), reg);
800 
801 	/*
802 	 * Calculate the initial credit return threshold.
803 	 *
804 	 * For Ack contexts, set a threshold for half the credits.
805 	 * For User contexts use the given percentage.  This has been
806 	 * sanitized on driver start-up.
807 	 * For Kernel contexts, use the default MTU plus a header
808 	 * or half the credits, whichever is smaller. This should
809 	 * work for both the 3-deep buffering allocation and the
810 	 * pooling allocation.
811 	 */
812 	if (type == SC_ACK) {
813 		thresh = sc_percent_to_threshold(sc, 50);
814 	} else if (type == SC_USER) {
815 		thresh = sc_percent_to_threshold(sc,
816 						 user_credit_return_threshold);
817 	} else { /* kernel */
818 		thresh = min(sc_percent_to_threshold(sc, 50),
819 			     sc_mtu_to_threshold(sc, hfi1_max_mtu,
820 						 hdrqentsize));
821 	}
822 	reg = thresh << SC(CREDIT_CTRL_THRESHOLD_SHIFT);
823 	/* add in early return */
824 	if (type == SC_USER && HFI1_CAP_IS_USET(EARLY_CREDIT_RETURN))
825 		reg |= SC(CREDIT_CTRL_EARLY_RETURN_SMASK);
826 	else if (HFI1_CAP_IS_KSET(EARLY_CREDIT_RETURN)) /* kernel, ack */
827 		reg |= SC(CREDIT_CTRL_EARLY_RETURN_SMASK);
828 
829 	/* set up write-through credit_ctrl */
830 	sc->credit_ctrl = reg;
831 	write_kctxt_csr(dd, hw_context, SC(CREDIT_CTRL), reg);
832 
833 	/* User send contexts should not allow sending on VL15 */
834 	if (type == SC_USER) {
835 		reg = 1ULL << 15;
836 		write_kctxt_csr(dd, hw_context, SC(CHECK_VL), reg);
837 	}
838 
839 	spin_unlock_irqrestore(&dd->sc_lock, flags);
840 
841 	/*
842 	 * Allocate shadow ring to track outstanding PIO buffers _after_
843 	 * unlocking.  We don't know the size until the lock is held and
844 	 * we can't allocate while the lock is held.  No one is using
845 	 * the context yet, so allocate it now.
846 	 *
847 	 * User contexts do not get a shadow ring.
848 	 */
849 	if (type != SC_USER) {
850 		/*
851 		 * Size the shadow ring 1 larger than the number of credits
852 		 * so head == tail can mean empty.
853 		 */
854 		sc->sr_size = sci->credits + 1;
855 		sc->sr = kcalloc_node(sc->sr_size,
856 				      sizeof(union pio_shadow_ring),
857 				      GFP_KERNEL, numa);
858 		if (!sc->sr) {
859 			sc_free(sc);
860 			return NULL;
861 		}
862 	}
863 
864 	hfi1_cdbg(PIO,
865 		  "Send context %u(%u) %s group %u credits %u credit_ctrl 0x%llx threshold %u\n",
866 		  sw_index,
867 		  hw_context,
868 		  sc_type_name(type),
869 		  sc->group,
870 		  sc->credits,
871 		  sc->credit_ctrl,
872 		  thresh);
873 
874 	return sc;
875 }
876 
877 /* free a per-NUMA send context structure */
sc_free(struct send_context * sc)878 void sc_free(struct send_context *sc)
879 {
880 	struct hfi1_devdata *dd;
881 	unsigned long flags;
882 	u32 sw_index;
883 	u32 hw_context;
884 
885 	if (!sc)
886 		return;
887 
888 	sc->flags |= SCF_IN_FREE;	/* ensure no restarts */
889 	dd = sc->dd;
890 	if (!list_empty(&sc->piowait))
891 		dd_dev_err(dd, "piowait list not empty!\n");
892 	sw_index = sc->sw_index;
893 	hw_context = sc->hw_context;
894 	sc_disable(sc);	/* make sure the HW is disabled */
895 	flush_work(&sc->halt_work);
896 
897 	spin_lock_irqsave(&dd->sc_lock, flags);
898 	dd->send_contexts[sw_index].sc = NULL;
899 
900 	/* clear/disable all registers set in sc_alloc */
901 	write_kctxt_csr(dd, hw_context, SC(CTRL), 0);
902 	write_kctxt_csr(dd, hw_context, SC(CHECK_ENABLE), 0);
903 	write_kctxt_csr(dd, hw_context, SC(ERR_MASK), 0);
904 	write_kctxt_csr(dd, hw_context, SC(CHECK_PARTITION_KEY), 0);
905 	write_kctxt_csr(dd, hw_context, SC(CHECK_OPCODE), 0);
906 	write_kctxt_csr(dd, hw_context, SC(CREDIT_RETURN_ADDR), 0);
907 	write_kctxt_csr(dd, hw_context, SC(CREDIT_CTRL), 0);
908 
909 	/* release the index and context for re-use */
910 	sc_hw_free(dd, sw_index, hw_context);
911 	spin_unlock_irqrestore(&dd->sc_lock, flags);
912 
913 	kfree(sc->sr);
914 	free_percpu(sc->buffers_allocated);
915 	kfree(sc);
916 }
917 
918 /* disable the context */
sc_disable(struct send_context * sc)919 void sc_disable(struct send_context *sc)
920 {
921 	u64 reg;
922 	struct pio_buf *pbuf;
923 	LIST_HEAD(wake_list);
924 
925 	if (!sc)
926 		return;
927 
928 	/* do all steps, even if already disabled */
929 	spin_lock_irq(&sc->alloc_lock);
930 	reg = read_kctxt_csr(sc->dd, sc->hw_context, SC(CTRL));
931 	reg &= ~SC(CTRL_CTXT_ENABLE_SMASK);
932 	sc->flags &= ~SCF_ENABLED;
933 	sc_wait_for_packet_egress(sc, 1);
934 	write_kctxt_csr(sc->dd, sc->hw_context, SC(CTRL), reg);
935 
936 	/*
937 	 * Flush any waiters.  Once the context is disabled,
938 	 * credit return interrupts are stopped (although there
939 	 * could be one in-process when the context is disabled).
940 	 * Wait one microsecond for any lingering interrupts, then
941 	 * proceed with the flush.
942 	 */
943 	udelay(1);
944 	spin_lock(&sc->release_lock);
945 	if (sc->sr) {	/* this context has a shadow ring */
946 		while (sc->sr_tail != sc->sr_head) {
947 			pbuf = &sc->sr[sc->sr_tail].pbuf;
948 			if (pbuf->cb)
949 				(*pbuf->cb)(pbuf->arg, PRC_SC_DISABLE);
950 			sc->sr_tail++;
951 			if (sc->sr_tail >= sc->sr_size)
952 				sc->sr_tail = 0;
953 		}
954 	}
955 	spin_unlock(&sc->release_lock);
956 
957 	write_seqlock(&sc->waitlock);
958 	list_splice_init(&sc->piowait, &wake_list);
959 	write_sequnlock(&sc->waitlock);
960 	while (!list_empty(&wake_list)) {
961 		struct iowait *wait;
962 		struct rvt_qp *qp;
963 		struct hfi1_qp_priv *priv;
964 
965 		wait = list_first_entry(&wake_list, struct iowait, list);
966 		qp = iowait_to_qp(wait);
967 		priv = qp->priv;
968 		list_del_init(&priv->s_iowait.list);
969 		priv->s_iowait.lock = NULL;
970 		hfi1_qp_wakeup(qp, RVT_S_WAIT_PIO | HFI1_S_WAIT_PIO_DRAIN);
971 	}
972 
973 	spin_unlock_irq(&sc->alloc_lock);
974 }
975 
976 /* return SendEgressCtxtStatus.PacketOccupancy */
packet_occupancy(u64 reg)977 static u64 packet_occupancy(u64 reg)
978 {
979 	return (reg &
980 		SEND_EGRESS_CTXT_STATUS_CTXT_EGRESS_PACKET_OCCUPANCY_SMASK)
981 		>> SEND_EGRESS_CTXT_STATUS_CTXT_EGRESS_PACKET_OCCUPANCY_SHIFT;
982 }
983 
984 /* is egress halted on the context? */
egress_halted(u64 reg)985 static bool egress_halted(u64 reg)
986 {
987 	return !!(reg & SEND_EGRESS_CTXT_STATUS_CTXT_EGRESS_HALT_STATUS_SMASK);
988 }
989 
990 /* is the send context halted? */
is_sc_halted(struct hfi1_devdata * dd,u32 hw_context)991 static bool is_sc_halted(struct hfi1_devdata *dd, u32 hw_context)
992 {
993 	return !!(read_kctxt_csr(dd, hw_context, SC(STATUS)) &
994 		  SC(STATUS_CTXT_HALTED_SMASK));
995 }
996 
997 /**
998  * sc_wait_for_packet_egress
999  * @sc: valid send context
1000  * @pause: wait for credit return
1001  *
1002  * Wait for packet egress, optionally pause for credit return
1003  *
1004  * Egress halt and Context halt are not necessarily the same thing, so
1005  * check for both.
1006  *
1007  * NOTE: The context halt bit may not be set immediately.  Because of this,
1008  * it is necessary to check the SW SFC_HALTED bit (set in the IRQ) and the HW
1009  * context bit to determine if the context is halted.
1010  */
sc_wait_for_packet_egress(struct send_context * sc,int pause)1011 static void sc_wait_for_packet_egress(struct send_context *sc, int pause)
1012 {
1013 	struct hfi1_devdata *dd = sc->dd;
1014 	u64 reg = 0;
1015 	u64 reg_prev;
1016 	u32 loop = 0;
1017 
1018 	while (1) {
1019 		reg_prev = reg;
1020 		reg = read_csr(dd, sc->hw_context * 8 +
1021 			       SEND_EGRESS_CTXT_STATUS);
1022 		/* done if any halt bits, SW or HW are set */
1023 		if (sc->flags & SCF_HALTED ||
1024 		    is_sc_halted(dd, sc->hw_context) || egress_halted(reg))
1025 			break;
1026 		reg = packet_occupancy(reg);
1027 		if (reg == 0)
1028 			break;
1029 		/* counter is reset if occupancy count changes */
1030 		if (reg != reg_prev)
1031 			loop = 0;
1032 		if (loop > 50000) {
1033 			/* timed out - bounce the link */
1034 			dd_dev_err(dd,
1035 				   "%s: context %u(%u) timeout waiting for packets to egress, remaining count %u, bouncing link\n",
1036 				   __func__, sc->sw_index,
1037 				   sc->hw_context, (u32)reg);
1038 			queue_work(dd->pport->link_wq,
1039 				   &dd->pport->link_bounce_work);
1040 			break;
1041 		}
1042 		loop++;
1043 		udelay(1);
1044 	}
1045 
1046 	if (pause)
1047 		/* Add additional delay to ensure chip returns all credits */
1048 		pause_for_credit_return(dd);
1049 }
1050 
sc_wait(struct hfi1_devdata * dd)1051 void sc_wait(struct hfi1_devdata *dd)
1052 {
1053 	int i;
1054 
1055 	for (i = 0; i < dd->num_send_contexts; i++) {
1056 		struct send_context *sc = dd->send_contexts[i].sc;
1057 
1058 		if (!sc)
1059 			continue;
1060 		sc_wait_for_packet_egress(sc, 0);
1061 	}
1062 }
1063 
1064 /*
1065  * Restart a context after it has been halted due to error.
1066  *
1067  * If the first step fails - wait for the halt to be asserted, return early.
1068  * Otherwise complain about timeouts but keep going.
1069  *
1070  * It is expected that allocations (enabled flag bit) have been shut off
1071  * already (only applies to kernel contexts).
1072  */
sc_restart(struct send_context * sc)1073 int sc_restart(struct send_context *sc)
1074 {
1075 	struct hfi1_devdata *dd = sc->dd;
1076 	u64 reg;
1077 	u32 loop;
1078 	int count;
1079 
1080 	/* bounce off if not halted, or being free'd */
1081 	if (!(sc->flags & SCF_HALTED) || (sc->flags & SCF_IN_FREE))
1082 		return -EINVAL;
1083 
1084 	dd_dev_info(dd, "restarting send context %u(%u)\n", sc->sw_index,
1085 		    sc->hw_context);
1086 
1087 	/*
1088 	 * Step 1: Wait for the context to actually halt.
1089 	 *
1090 	 * The error interrupt is asynchronous to actually setting halt
1091 	 * on the context.
1092 	 */
1093 	loop = 0;
1094 	while (1) {
1095 		reg = read_kctxt_csr(dd, sc->hw_context, SC(STATUS));
1096 		if (reg & SC(STATUS_CTXT_HALTED_SMASK))
1097 			break;
1098 		if (loop > 100) {
1099 			dd_dev_err(dd, "%s: context %u(%u) not halting, skipping\n",
1100 				   __func__, sc->sw_index, sc->hw_context);
1101 			return -ETIME;
1102 		}
1103 		loop++;
1104 		udelay(1);
1105 	}
1106 
1107 	/*
1108 	 * Step 2: Ensure no users are still trying to write to PIO.
1109 	 *
1110 	 * For kernel contexts, we have already turned off buffer allocation.
1111 	 * Now wait for the buffer count to go to zero.
1112 	 *
1113 	 * For user contexts, the user handling code has cut off write access
1114 	 * to the context's PIO pages before calling this routine and will
1115 	 * restore write access after this routine returns.
1116 	 */
1117 	if (sc->type != SC_USER) {
1118 		/* kernel context */
1119 		loop = 0;
1120 		while (1) {
1121 			count = get_buffers_allocated(sc);
1122 			if (count == 0)
1123 				break;
1124 			if (loop > 100) {
1125 				dd_dev_err(dd,
1126 					   "%s: context %u(%u) timeout waiting for PIO buffers to zero, remaining %d\n",
1127 					   __func__, sc->sw_index,
1128 					   sc->hw_context, count);
1129 			}
1130 			loop++;
1131 			udelay(1);
1132 		}
1133 	}
1134 
1135 	/*
1136 	 * Step 3: Wait for all packets to egress.
1137 	 * This is done while disabling the send context
1138 	 *
1139 	 * Step 4: Disable the context
1140 	 *
1141 	 * This is a superset of the halt.  After the disable, the
1142 	 * errors can be cleared.
1143 	 */
1144 	sc_disable(sc);
1145 
1146 	/*
1147 	 * Step 5: Enable the context
1148 	 *
1149 	 * This enable will clear the halted flag and per-send context
1150 	 * error flags.
1151 	 */
1152 	return sc_enable(sc);
1153 }
1154 
1155 /*
1156  * PIO freeze processing.  To be called after the TXE block is fully frozen.
1157  * Go through all frozen send contexts and disable them.  The contexts are
1158  * already stopped by the freeze.
1159  */
pio_freeze(struct hfi1_devdata * dd)1160 void pio_freeze(struct hfi1_devdata *dd)
1161 {
1162 	struct send_context *sc;
1163 	int i;
1164 
1165 	for (i = 0; i < dd->num_send_contexts; i++) {
1166 		sc = dd->send_contexts[i].sc;
1167 		/*
1168 		 * Don't disable unallocated, unfrozen, or user send contexts.
1169 		 * User send contexts will be disabled when the process
1170 		 * calls into the driver to reset its context.
1171 		 */
1172 		if (!sc || !(sc->flags & SCF_FROZEN) || sc->type == SC_USER)
1173 			continue;
1174 
1175 		/* only need to disable, the context is already stopped */
1176 		sc_disable(sc);
1177 	}
1178 }
1179 
1180 /*
1181  * Unfreeze PIO for kernel send contexts.  The precondition for calling this
1182  * is that all PIO send contexts have been disabled and the SPC freeze has
1183  * been cleared.  Now perform the last step and re-enable each kernel context.
1184  * User (PSM) processing will occur when PSM calls into the kernel to
1185  * acknowledge the freeze.
1186  */
pio_kernel_unfreeze(struct hfi1_devdata * dd)1187 void pio_kernel_unfreeze(struct hfi1_devdata *dd)
1188 {
1189 	struct send_context *sc;
1190 	int i;
1191 
1192 	for (i = 0; i < dd->num_send_contexts; i++) {
1193 		sc = dd->send_contexts[i].sc;
1194 		if (!sc || !(sc->flags & SCF_FROZEN) || sc->type == SC_USER)
1195 			continue;
1196 		if (sc->flags & SCF_LINK_DOWN)
1197 			continue;
1198 
1199 		sc_enable(sc);	/* will clear the sc frozen flag */
1200 	}
1201 }
1202 
1203 /**
1204  * pio_kernel_linkup() - Re-enable send contexts after linkup event
1205  * @dd: valid devive data
1206  *
1207  * When the link goes down, the freeze path is taken.  However, a link down
1208  * event is different from a freeze because if the send context is re-enabled
1209  * whowever is sending data will start sending data again, which will hang
1210  * any QP that is sending data.
1211  *
1212  * The freeze path now looks at the type of event that occurs and takes this
1213  * path for link down event.
1214  */
pio_kernel_linkup(struct hfi1_devdata * dd)1215 void pio_kernel_linkup(struct hfi1_devdata *dd)
1216 {
1217 	struct send_context *sc;
1218 	int i;
1219 
1220 	for (i = 0; i < dd->num_send_contexts; i++) {
1221 		sc = dd->send_contexts[i].sc;
1222 		if (!sc || !(sc->flags & SCF_LINK_DOWN) || sc->type == SC_USER)
1223 			continue;
1224 
1225 		sc_enable(sc);	/* will clear the sc link down flag */
1226 	}
1227 }
1228 
1229 /*
1230  * Wait for the SendPioInitCtxt.PioInitInProgress bit to clear.
1231  * Returns:
1232  *	-ETIMEDOUT - if we wait too long
1233  *	-EIO	   - if there was an error
1234  */
pio_init_wait_progress(struct hfi1_devdata * dd)1235 static int pio_init_wait_progress(struct hfi1_devdata *dd)
1236 {
1237 	u64 reg;
1238 	int max, count = 0;
1239 
1240 	/* max is the longest possible HW init time / delay */
1241 	max = (dd->icode == ICODE_FPGA_EMULATION) ? 120 : 5;
1242 	while (1) {
1243 		reg = read_csr(dd, SEND_PIO_INIT_CTXT);
1244 		if (!(reg & SEND_PIO_INIT_CTXT_PIO_INIT_IN_PROGRESS_SMASK))
1245 			break;
1246 		if (count >= max)
1247 			return -ETIMEDOUT;
1248 		udelay(5);
1249 		count++;
1250 	}
1251 
1252 	return reg & SEND_PIO_INIT_CTXT_PIO_INIT_ERR_SMASK ? -EIO : 0;
1253 }
1254 
1255 /*
1256  * Reset all of the send contexts to their power-on state.  Used
1257  * only during manual init - no lock against sc_enable needed.
1258  */
pio_reset_all(struct hfi1_devdata * dd)1259 void pio_reset_all(struct hfi1_devdata *dd)
1260 {
1261 	int ret;
1262 
1263 	/* make sure the init engine is not busy */
1264 	ret = pio_init_wait_progress(dd);
1265 	/* ignore any timeout */
1266 	if (ret == -EIO) {
1267 		/* clear the error */
1268 		write_csr(dd, SEND_PIO_ERR_CLEAR,
1269 			  SEND_PIO_ERR_CLEAR_PIO_INIT_SM_IN_ERR_SMASK);
1270 	}
1271 
1272 	/* reset init all */
1273 	write_csr(dd, SEND_PIO_INIT_CTXT,
1274 		  SEND_PIO_INIT_CTXT_PIO_ALL_CTXT_INIT_SMASK);
1275 	udelay(2);
1276 	ret = pio_init_wait_progress(dd);
1277 	if (ret < 0) {
1278 		dd_dev_err(dd,
1279 			   "PIO send context init %s while initializing all PIO blocks\n",
1280 			   ret == -ETIMEDOUT ? "is stuck" : "had an error");
1281 	}
1282 }
1283 
1284 /* enable the context */
sc_enable(struct send_context * sc)1285 int sc_enable(struct send_context *sc)
1286 {
1287 	u64 sc_ctrl, reg, pio;
1288 	struct hfi1_devdata *dd;
1289 	unsigned long flags;
1290 	int ret = 0;
1291 
1292 	if (!sc)
1293 		return -EINVAL;
1294 	dd = sc->dd;
1295 
1296 	/*
1297 	 * Obtain the allocator lock to guard against any allocation
1298 	 * attempts (which should not happen prior to context being
1299 	 * enabled). On the release/disable side we don't need to
1300 	 * worry about locking since the releaser will not do anything
1301 	 * if the context accounting values have not changed.
1302 	 */
1303 	spin_lock_irqsave(&sc->alloc_lock, flags);
1304 	sc_ctrl = read_kctxt_csr(dd, sc->hw_context, SC(CTRL));
1305 	if ((sc_ctrl & SC(CTRL_CTXT_ENABLE_SMASK)))
1306 		goto unlock; /* already enabled */
1307 
1308 	/* IMPORTANT: only clear free and fill if transitioning 0 -> 1 */
1309 
1310 	*sc->hw_free = 0;
1311 	sc->free = 0;
1312 	sc->alloc_free = 0;
1313 	sc->fill = 0;
1314 	sc->fill_wrap = 0;
1315 	sc->sr_head = 0;
1316 	sc->sr_tail = 0;
1317 	sc->flags = 0;
1318 	/* the alloc lock insures no fast path allocation */
1319 	reset_buffers_allocated(sc);
1320 
1321 	/*
1322 	 * Clear all per-context errors.  Some of these will be set when
1323 	 * we are re-enabling after a context halt.  Now that the context
1324 	 * is disabled, the halt will not clear until after the PIO init
1325 	 * engine runs below.
1326 	 */
1327 	reg = read_kctxt_csr(dd, sc->hw_context, SC(ERR_STATUS));
1328 	if (reg)
1329 		write_kctxt_csr(dd, sc->hw_context, SC(ERR_CLEAR), reg);
1330 
1331 	/*
1332 	 * The HW PIO initialization engine can handle only one init
1333 	 * request at a time. Serialize access to each device's engine.
1334 	 */
1335 	spin_lock(&dd->sc_init_lock);
1336 	/*
1337 	 * Since access to this code block is serialized and
1338 	 * each access waits for the initialization to complete
1339 	 * before releasing the lock, the PIO initialization engine
1340 	 * should not be in use, so we don't have to wait for the
1341 	 * InProgress bit to go down.
1342 	 */
1343 	pio = ((sc->hw_context & SEND_PIO_INIT_CTXT_PIO_CTXT_NUM_MASK) <<
1344 	       SEND_PIO_INIT_CTXT_PIO_CTXT_NUM_SHIFT) |
1345 		SEND_PIO_INIT_CTXT_PIO_SINGLE_CTXT_INIT_SMASK;
1346 	write_csr(dd, SEND_PIO_INIT_CTXT, pio);
1347 	/*
1348 	 * Wait until the engine is done.  Give the chip the required time
1349 	 * so, hopefully, we read the register just once.
1350 	 */
1351 	udelay(2);
1352 	ret = pio_init_wait_progress(dd);
1353 	spin_unlock(&dd->sc_init_lock);
1354 	if (ret) {
1355 		dd_dev_err(dd,
1356 			   "sctxt%u(%u): Context not enabled due to init failure %d\n",
1357 			   sc->sw_index, sc->hw_context, ret);
1358 		goto unlock;
1359 	}
1360 
1361 	/*
1362 	 * All is well. Enable the context.
1363 	 */
1364 	sc_ctrl |= SC(CTRL_CTXT_ENABLE_SMASK);
1365 	write_kctxt_csr(dd, sc->hw_context, SC(CTRL), sc_ctrl);
1366 	/*
1367 	 * Read SendCtxtCtrl to force the write out and prevent a timing
1368 	 * hazard where a PIO write may reach the context before the enable.
1369 	 */
1370 	read_kctxt_csr(dd, sc->hw_context, SC(CTRL));
1371 	sc->flags |= SCF_ENABLED;
1372 
1373 unlock:
1374 	spin_unlock_irqrestore(&sc->alloc_lock, flags);
1375 
1376 	return ret;
1377 }
1378 
1379 /* force a credit return on the context */
sc_return_credits(struct send_context * sc)1380 void sc_return_credits(struct send_context *sc)
1381 {
1382 	if (!sc)
1383 		return;
1384 
1385 	/* a 0->1 transition schedules a credit return */
1386 	write_kctxt_csr(sc->dd, sc->hw_context, SC(CREDIT_FORCE),
1387 			SC(CREDIT_FORCE_FORCE_RETURN_SMASK));
1388 	/*
1389 	 * Ensure that the write is flushed and the credit return is
1390 	 * scheduled. We care more about the 0 -> 1 transition.
1391 	 */
1392 	read_kctxt_csr(sc->dd, sc->hw_context, SC(CREDIT_FORCE));
1393 	/* set back to 0 for next time */
1394 	write_kctxt_csr(sc->dd, sc->hw_context, SC(CREDIT_FORCE), 0);
1395 }
1396 
1397 /* allow all in-flight packets to drain on the context */
sc_flush(struct send_context * sc)1398 void sc_flush(struct send_context *sc)
1399 {
1400 	if (!sc)
1401 		return;
1402 
1403 	sc_wait_for_packet_egress(sc, 1);
1404 }
1405 
1406 /* drop all packets on the context, no waiting until they are sent */
sc_drop(struct send_context * sc)1407 void sc_drop(struct send_context *sc)
1408 {
1409 	if (!sc)
1410 		return;
1411 
1412 	dd_dev_info(sc->dd, "%s: context %u(%u) - not implemented\n",
1413 		    __func__, sc->sw_index, sc->hw_context);
1414 }
1415 
1416 /*
1417  * Start the software reaction to a context halt or SPC freeze:
1418  *	- mark the context as halted or frozen
1419  *	- stop buffer allocations
1420  *
1421  * Called from the error interrupt.  Other work is deferred until
1422  * out of the interrupt.
1423  */
sc_stop(struct send_context * sc,int flag)1424 void sc_stop(struct send_context *sc, int flag)
1425 {
1426 	unsigned long flags;
1427 
1428 	/* stop buffer allocations */
1429 	spin_lock_irqsave(&sc->alloc_lock, flags);
1430 	/* mark the context */
1431 	sc->flags |= flag;
1432 	sc->flags &= ~SCF_ENABLED;
1433 	spin_unlock_irqrestore(&sc->alloc_lock, flags);
1434 	wake_up(&sc->halt_wait);
1435 }
1436 
1437 #define BLOCK_DWORDS (PIO_BLOCK_SIZE / sizeof(u32))
1438 #define dwords_to_blocks(x) DIV_ROUND_UP(x, BLOCK_DWORDS)
1439 
1440 /*
1441  * The send context buffer "allocator".
1442  *
1443  * @sc: the PIO send context we are allocating from
1444  * @len: length of whole packet - including PBC - in dwords
1445  * @cb: optional callback to call when the buffer is finished sending
1446  * @arg: argument for cb
1447  *
1448  * Return a pointer to a PIO buffer, NULL if not enough room, -ECOMM
1449  * when link is down.
1450  */
sc_buffer_alloc(struct send_context * sc,u32 dw_len,pio_release_cb cb,void * arg)1451 struct pio_buf *sc_buffer_alloc(struct send_context *sc, u32 dw_len,
1452 				pio_release_cb cb, void *arg)
1453 {
1454 	struct pio_buf *pbuf = NULL;
1455 	unsigned long flags;
1456 	unsigned long avail;
1457 	unsigned long blocks = dwords_to_blocks(dw_len);
1458 	u32 fill_wrap;
1459 	int trycount = 0;
1460 	u32 head, next;
1461 
1462 	spin_lock_irqsave(&sc->alloc_lock, flags);
1463 	if (!(sc->flags & SCF_ENABLED)) {
1464 		spin_unlock_irqrestore(&sc->alloc_lock, flags);
1465 		return ERR_PTR(-ECOMM);
1466 	}
1467 
1468 retry:
1469 	avail = (unsigned long)sc->credits - (sc->fill - sc->alloc_free);
1470 	if (blocks > avail) {
1471 		/* not enough room */
1472 		if (unlikely(trycount))	{ /* already tried to get more room */
1473 			spin_unlock_irqrestore(&sc->alloc_lock, flags);
1474 			goto done;
1475 		}
1476 		/* copy from receiver cache line and recalculate */
1477 		sc->alloc_free = READ_ONCE(sc->free);
1478 		avail =
1479 			(unsigned long)sc->credits -
1480 			(sc->fill - sc->alloc_free);
1481 		if (blocks > avail) {
1482 			/* still no room, actively update */
1483 			sc_release_update(sc);
1484 			sc->alloc_free = READ_ONCE(sc->free);
1485 			trycount++;
1486 			goto retry;
1487 		}
1488 	}
1489 
1490 	/* there is enough room */
1491 
1492 	preempt_disable();
1493 	this_cpu_inc(*sc->buffers_allocated);
1494 
1495 	/* read this once */
1496 	head = sc->sr_head;
1497 
1498 	/* "allocate" the buffer */
1499 	sc->fill += blocks;
1500 	fill_wrap = sc->fill_wrap;
1501 	sc->fill_wrap += blocks;
1502 	if (sc->fill_wrap >= sc->credits)
1503 		sc->fill_wrap = sc->fill_wrap - sc->credits;
1504 
1505 	/*
1506 	 * Fill the parts that the releaser looks at before moving the head.
1507 	 * The only necessary piece is the sent_at field.  The credits
1508 	 * we have just allocated cannot have been returned yet, so the
1509 	 * cb and arg will not be looked at for a "while".  Put them
1510 	 * on this side of the memory barrier anyway.
1511 	 */
1512 	pbuf = &sc->sr[head].pbuf;
1513 	pbuf->sent_at = sc->fill;
1514 	pbuf->cb = cb;
1515 	pbuf->arg = arg;
1516 	pbuf->sc = sc;	/* could be filled in at sc->sr init time */
1517 	/* make sure this is in memory before updating the head */
1518 
1519 	/* calculate next head index, do not store */
1520 	next = head + 1;
1521 	if (next >= sc->sr_size)
1522 		next = 0;
1523 	/*
1524 	 * update the head - must be last! - the releaser can look at fields
1525 	 * in pbuf once we move the head
1526 	 */
1527 	smp_wmb();
1528 	sc->sr_head = next;
1529 	spin_unlock_irqrestore(&sc->alloc_lock, flags);
1530 
1531 	/* finish filling in the buffer outside the lock */
1532 	pbuf->start = sc->base_addr + fill_wrap * PIO_BLOCK_SIZE;
1533 	pbuf->end = sc->base_addr + sc->size;
1534 	pbuf->qw_written = 0;
1535 	pbuf->carry_bytes = 0;
1536 	pbuf->carry.val64 = 0;
1537 done:
1538 	return pbuf;
1539 }
1540 
1541 /*
1542  * There are at least two entities that can turn on credit return
1543  * interrupts and they can overlap.  Avoid problems by implementing
1544  * a count scheme that is enforced by a lock.  The lock is needed because
1545  * the count and CSR write must be paired.
1546  */
1547 
1548 /*
1549  * Start credit return interrupts.  This is managed by a count.  If already
1550  * on, just increment the count.
1551  */
sc_add_credit_return_intr(struct send_context * sc)1552 void sc_add_credit_return_intr(struct send_context *sc)
1553 {
1554 	unsigned long flags;
1555 
1556 	/* lock must surround both the count change and the CSR update */
1557 	spin_lock_irqsave(&sc->credit_ctrl_lock, flags);
1558 	if (sc->credit_intr_count == 0) {
1559 		sc->credit_ctrl |= SC(CREDIT_CTRL_CREDIT_INTR_SMASK);
1560 		write_kctxt_csr(sc->dd, sc->hw_context,
1561 				SC(CREDIT_CTRL), sc->credit_ctrl);
1562 	}
1563 	sc->credit_intr_count++;
1564 	spin_unlock_irqrestore(&sc->credit_ctrl_lock, flags);
1565 }
1566 
1567 /*
1568  * Stop credit return interrupts.  This is managed by a count.  Decrement the
1569  * count, if the last user, then turn the credit interrupts off.
1570  */
sc_del_credit_return_intr(struct send_context * sc)1571 void sc_del_credit_return_intr(struct send_context *sc)
1572 {
1573 	unsigned long flags;
1574 
1575 	WARN_ON(sc->credit_intr_count == 0);
1576 
1577 	/* lock must surround both the count change and the CSR update */
1578 	spin_lock_irqsave(&sc->credit_ctrl_lock, flags);
1579 	sc->credit_intr_count--;
1580 	if (sc->credit_intr_count == 0) {
1581 		sc->credit_ctrl &= ~SC(CREDIT_CTRL_CREDIT_INTR_SMASK);
1582 		write_kctxt_csr(sc->dd, sc->hw_context,
1583 				SC(CREDIT_CTRL), sc->credit_ctrl);
1584 	}
1585 	spin_unlock_irqrestore(&sc->credit_ctrl_lock, flags);
1586 }
1587 
1588 /*
1589  * The caller must be careful when calling this.  All needint calls
1590  * must be paired with !needint.
1591  */
hfi1_sc_wantpiobuf_intr(struct send_context * sc,u32 needint)1592 void hfi1_sc_wantpiobuf_intr(struct send_context *sc, u32 needint)
1593 {
1594 	if (needint)
1595 		sc_add_credit_return_intr(sc);
1596 	else
1597 		sc_del_credit_return_intr(sc);
1598 	trace_hfi1_wantpiointr(sc, needint, sc->credit_ctrl);
1599 	if (needint)
1600 		sc_return_credits(sc);
1601 }
1602 
1603 /**
1604  * sc_piobufavail - callback when a PIO buffer is available
1605  * @sc: the send context
1606  *
1607  * This is called from the interrupt handler when a PIO buffer is
1608  * available after hfi1_verbs_send() returned an error that no buffers were
1609  * available. Disable the interrupt if there are no more QPs waiting.
1610  */
sc_piobufavail(struct send_context * sc)1611 static void sc_piobufavail(struct send_context *sc)
1612 {
1613 	struct hfi1_devdata *dd = sc->dd;
1614 	struct list_head *list;
1615 	struct rvt_qp *qps[PIO_WAIT_BATCH_SIZE];
1616 	struct rvt_qp *qp;
1617 	struct hfi1_qp_priv *priv;
1618 	unsigned long flags;
1619 	uint i, n = 0, top_idx = 0;
1620 
1621 	if (dd->send_contexts[sc->sw_index].type != SC_KERNEL &&
1622 	    dd->send_contexts[sc->sw_index].type != SC_VL15)
1623 		return;
1624 	list = &sc->piowait;
1625 	/*
1626 	 * Note: checking that the piowait list is empty and clearing
1627 	 * the buffer available interrupt needs to be atomic or we
1628 	 * could end up with QPs on the wait list with the interrupt
1629 	 * disabled.
1630 	 */
1631 	write_seqlock_irqsave(&sc->waitlock, flags);
1632 	while (!list_empty(list)) {
1633 		struct iowait *wait;
1634 
1635 		if (n == ARRAY_SIZE(qps))
1636 			break;
1637 		wait = list_first_entry(list, struct iowait, list);
1638 		iowait_get_priority(wait);
1639 		qp = iowait_to_qp(wait);
1640 		priv = qp->priv;
1641 		list_del_init(&priv->s_iowait.list);
1642 		priv->s_iowait.lock = NULL;
1643 		if (n) {
1644 			priv = qps[top_idx]->priv;
1645 			top_idx = iowait_priority_update_top(wait,
1646 							     &priv->s_iowait,
1647 							     n, top_idx);
1648 		}
1649 
1650 		/* refcount held until actual wake up */
1651 		qps[n++] = qp;
1652 	}
1653 	/*
1654 	 * If there had been waiters and there are more
1655 	 * insure that we redo the force to avoid a potential hang.
1656 	 */
1657 	if (n) {
1658 		hfi1_sc_wantpiobuf_intr(sc, 0);
1659 		if (!list_empty(list))
1660 			hfi1_sc_wantpiobuf_intr(sc, 1);
1661 	}
1662 	write_sequnlock_irqrestore(&sc->waitlock, flags);
1663 
1664 	/* Wake up the top-priority one first */
1665 	if (n)
1666 		hfi1_qp_wakeup(qps[top_idx],
1667 			       RVT_S_WAIT_PIO | HFI1_S_WAIT_PIO_DRAIN);
1668 	for (i = 0; i < n; i++)
1669 		if (i != top_idx)
1670 			hfi1_qp_wakeup(qps[i],
1671 				       RVT_S_WAIT_PIO | HFI1_S_WAIT_PIO_DRAIN);
1672 }
1673 
1674 /* translate a send credit update to a bit code of reasons */
fill_code(u64 hw_free)1675 static inline int fill_code(u64 hw_free)
1676 {
1677 	int code = 0;
1678 
1679 	if (hw_free & CR_STATUS_SMASK)
1680 		code |= PRC_STATUS_ERR;
1681 	if (hw_free & CR_CREDIT_RETURN_DUE_TO_PBC_SMASK)
1682 		code |= PRC_PBC;
1683 	if (hw_free & CR_CREDIT_RETURN_DUE_TO_THRESHOLD_SMASK)
1684 		code |= PRC_THRESHOLD;
1685 	if (hw_free & CR_CREDIT_RETURN_DUE_TO_ERR_SMASK)
1686 		code |= PRC_FILL_ERR;
1687 	if (hw_free & CR_CREDIT_RETURN_DUE_TO_FORCE_SMASK)
1688 		code |= PRC_SC_DISABLE;
1689 	return code;
1690 }
1691 
1692 /* use the jiffies compare to get the wrap right */
1693 #define sent_before(a, b) time_before(a, b)	/* a < b */
1694 
1695 /*
1696  * The send context buffer "releaser".
1697  */
sc_release_update(struct send_context * sc)1698 void sc_release_update(struct send_context *sc)
1699 {
1700 	struct pio_buf *pbuf;
1701 	u64 hw_free;
1702 	u32 head, tail;
1703 	unsigned long old_free;
1704 	unsigned long free;
1705 	unsigned long extra;
1706 	unsigned long flags;
1707 	int code;
1708 
1709 	if (!sc)
1710 		return;
1711 
1712 	spin_lock_irqsave(&sc->release_lock, flags);
1713 	/* update free */
1714 	hw_free = le64_to_cpu(*sc->hw_free);		/* volatile read */
1715 	old_free = sc->free;
1716 	extra = (((hw_free & CR_COUNTER_SMASK) >> CR_COUNTER_SHIFT)
1717 			- (old_free & CR_COUNTER_MASK))
1718 				& CR_COUNTER_MASK;
1719 	free = old_free + extra;
1720 	trace_hfi1_piofree(sc, extra);
1721 
1722 	/* call sent buffer callbacks */
1723 	code = -1;				/* code not yet set */
1724 	head = READ_ONCE(sc->sr_head);	/* snapshot the head */
1725 	tail = sc->sr_tail;
1726 	while (head != tail) {
1727 		pbuf = &sc->sr[tail].pbuf;
1728 
1729 		if (sent_before(free, pbuf->sent_at)) {
1730 			/* not sent yet */
1731 			break;
1732 		}
1733 		if (pbuf->cb) {
1734 			if (code < 0) /* fill in code on first user */
1735 				code = fill_code(hw_free);
1736 			(*pbuf->cb)(pbuf->arg, code);
1737 		}
1738 
1739 		tail++;
1740 		if (tail >= sc->sr_size)
1741 			tail = 0;
1742 	}
1743 	sc->sr_tail = tail;
1744 	/* make sure tail is updated before free */
1745 	smp_wmb();
1746 	sc->free = free;
1747 	spin_unlock_irqrestore(&sc->release_lock, flags);
1748 	sc_piobufavail(sc);
1749 }
1750 
1751 /*
1752  * Send context group releaser.  Argument is the send context that caused
1753  * the interrupt.  Called from the send context interrupt handler.
1754  *
1755  * Call release on all contexts in the group.
1756  *
1757  * This routine takes the sc_lock without an irqsave because it is only
1758  * called from an interrupt handler.  Adjust if that changes.
1759  */
sc_group_release_update(struct hfi1_devdata * dd,u32 hw_context)1760 void sc_group_release_update(struct hfi1_devdata *dd, u32 hw_context)
1761 {
1762 	struct send_context *sc;
1763 	u32 sw_index;
1764 	u32 gc, gc_end;
1765 
1766 	spin_lock(&dd->sc_lock);
1767 	sw_index = dd->hw_to_sw[hw_context];
1768 	if (unlikely(sw_index >= dd->num_send_contexts)) {
1769 		dd_dev_err(dd, "%s: invalid hw (%u) to sw (%u) mapping\n",
1770 			   __func__, hw_context, sw_index);
1771 		goto done;
1772 	}
1773 	sc = dd->send_contexts[sw_index].sc;
1774 	if (unlikely(!sc))
1775 		goto done;
1776 
1777 	gc = group_context(hw_context, sc->group);
1778 	gc_end = gc + group_size(sc->group);
1779 	for (; gc < gc_end; gc++) {
1780 		sw_index = dd->hw_to_sw[gc];
1781 		if (unlikely(sw_index >= dd->num_send_contexts)) {
1782 			dd_dev_err(dd,
1783 				   "%s: invalid hw (%u) to sw (%u) mapping\n",
1784 				   __func__, hw_context, sw_index);
1785 			continue;
1786 		}
1787 		sc_release_update(dd->send_contexts[sw_index].sc);
1788 	}
1789 done:
1790 	spin_unlock(&dd->sc_lock);
1791 }
1792 
1793 /*
1794  * pio_select_send_context_vl() - select send context
1795  * @dd: devdata
1796  * @selector: a spreading factor
1797  * @vl: this vl
1798  *
1799  * This function returns a send context based on the selector and a vl.
1800  * The mapping fields are protected by RCU
1801  */
pio_select_send_context_vl(struct hfi1_devdata * dd,u32 selector,u8 vl)1802 struct send_context *pio_select_send_context_vl(struct hfi1_devdata *dd,
1803 						u32 selector, u8 vl)
1804 {
1805 	struct pio_vl_map *m;
1806 	struct pio_map_elem *e;
1807 	struct send_context *rval;
1808 
1809 	/*
1810 	 * NOTE This should only happen if SC->VL changed after the initial
1811 	 * checks on the QP/AH
1812 	 * Default will return VL0's send context below
1813 	 */
1814 	if (unlikely(vl >= num_vls)) {
1815 		rval = NULL;
1816 		goto done;
1817 	}
1818 
1819 	rcu_read_lock();
1820 	m = rcu_dereference(dd->pio_map);
1821 	if (unlikely(!m)) {
1822 		rcu_read_unlock();
1823 		return dd->vld[0].sc;
1824 	}
1825 	e = m->map[vl & m->mask];
1826 	rval = e->ksc[selector & e->mask];
1827 	rcu_read_unlock();
1828 
1829 done:
1830 	rval = !rval ? dd->vld[0].sc : rval;
1831 	return rval;
1832 }
1833 
1834 /*
1835  * pio_select_send_context_sc() - select send context
1836  * @dd: devdata
1837  * @selector: a spreading factor
1838  * @sc5: the 5 bit sc
1839  *
1840  * This function returns an send context based on the selector and an sc
1841  */
pio_select_send_context_sc(struct hfi1_devdata * dd,u32 selector,u8 sc5)1842 struct send_context *pio_select_send_context_sc(struct hfi1_devdata *dd,
1843 						u32 selector, u8 sc5)
1844 {
1845 	u8 vl = sc_to_vlt(dd, sc5);
1846 
1847 	return pio_select_send_context_vl(dd, selector, vl);
1848 }
1849 
1850 /*
1851  * Free the indicated map struct
1852  */
pio_map_free(struct pio_vl_map * m)1853 static void pio_map_free(struct pio_vl_map *m)
1854 {
1855 	int i;
1856 
1857 	for (i = 0; m && i < m->actual_vls; i++)
1858 		kfree(m->map[i]);
1859 	kfree(m);
1860 }
1861 
1862 /*
1863  * Handle RCU callback
1864  */
pio_map_rcu_callback(struct rcu_head * list)1865 static void pio_map_rcu_callback(struct rcu_head *list)
1866 {
1867 	struct pio_vl_map *m = container_of(list, struct pio_vl_map, list);
1868 
1869 	pio_map_free(m);
1870 }
1871 
1872 /*
1873  * Set credit return threshold for the kernel send context
1874  */
set_threshold(struct hfi1_devdata * dd,int scontext,int i)1875 static void set_threshold(struct hfi1_devdata *dd, int scontext, int i)
1876 {
1877 	u32 thres;
1878 
1879 	thres = min(sc_percent_to_threshold(dd->kernel_send_context[scontext],
1880 					    50),
1881 		    sc_mtu_to_threshold(dd->kernel_send_context[scontext],
1882 					dd->vld[i].mtu,
1883 					dd->rcd[0]->rcvhdrqentsize));
1884 	sc_set_cr_threshold(dd->kernel_send_context[scontext], thres);
1885 }
1886 
1887 /*
1888  * pio_map_init - called when #vls change
1889  * @dd: hfi1_devdata
1890  * @port: port number
1891  * @num_vls: number of vls
1892  * @vl_scontexts: per vl send context mapping (optional)
1893  *
1894  * This routine changes the mapping based on the number of vls.
1895  *
1896  * vl_scontexts is used to specify a non-uniform vl/send context
1897  * loading. NULL implies auto computing the loading and giving each
1898  * VL an uniform distribution of send contexts per VL.
1899  *
1900  * The auto algorithm computers the sc_per_vl and the number of extra
1901  * send contexts. Any extra send contexts are added from the last VL
1902  * on down
1903  *
1904  * rcu locking is used here to control access to the mapping fields.
1905  *
1906  * If either the num_vls or num_send_contexts are non-power of 2, the
1907  * array sizes in the struct pio_vl_map and the struct pio_map_elem are
1908  * rounded up to the next highest power of 2 and the first entry is
1909  * reused in a round robin fashion.
1910  *
1911  * If an error occurs the map change is not done and the mapping is not
1912  * chaged.
1913  *
1914  */
pio_map_init(struct hfi1_devdata * dd,u8 port,u8 num_vls,u8 * vl_scontexts)1915 int pio_map_init(struct hfi1_devdata *dd, u8 port, u8 num_vls, u8 *vl_scontexts)
1916 {
1917 	int i, j;
1918 	int extra, sc_per_vl;
1919 	int scontext = 1;
1920 	int num_kernel_send_contexts = 0;
1921 	u8 lvl_scontexts[OPA_MAX_VLS];
1922 	struct pio_vl_map *oldmap, *newmap;
1923 
1924 	if (!vl_scontexts) {
1925 		for (i = 0; i < dd->num_send_contexts; i++)
1926 			if (dd->send_contexts[i].type == SC_KERNEL)
1927 				num_kernel_send_contexts++;
1928 		/* truncate divide */
1929 		sc_per_vl = num_kernel_send_contexts / num_vls;
1930 		/* extras */
1931 		extra = num_kernel_send_contexts % num_vls;
1932 		vl_scontexts = lvl_scontexts;
1933 		/* add extras from last vl down */
1934 		for (i = num_vls - 1; i >= 0; i--, extra--)
1935 			vl_scontexts[i] = sc_per_vl + (extra > 0 ? 1 : 0);
1936 	}
1937 	/* build new map */
1938 	newmap = kzalloc(sizeof(*newmap) +
1939 			 roundup_pow_of_two(num_vls) *
1940 			 sizeof(struct pio_map_elem *),
1941 			 GFP_KERNEL);
1942 	if (!newmap)
1943 		goto bail;
1944 	newmap->actual_vls = num_vls;
1945 	newmap->vls = roundup_pow_of_two(num_vls);
1946 	newmap->mask = (1 << ilog2(newmap->vls)) - 1;
1947 	for (i = 0; i < newmap->vls; i++) {
1948 		/* save for wrap around */
1949 		int first_scontext = scontext;
1950 
1951 		if (i < newmap->actual_vls) {
1952 			int sz = roundup_pow_of_two(vl_scontexts[i]);
1953 
1954 			/* only allocate once */
1955 			newmap->map[i] = kzalloc(sizeof(*newmap->map[i]) +
1956 						 sz * sizeof(struct
1957 							     send_context *),
1958 						 GFP_KERNEL);
1959 			if (!newmap->map[i])
1960 				goto bail;
1961 			newmap->map[i]->mask = (1 << ilog2(sz)) - 1;
1962 			/*
1963 			 * assign send contexts and
1964 			 * adjust credit return threshold
1965 			 */
1966 			for (j = 0; j < sz; j++) {
1967 				if (dd->kernel_send_context[scontext]) {
1968 					newmap->map[i]->ksc[j] =
1969 					dd->kernel_send_context[scontext];
1970 					set_threshold(dd, scontext, i);
1971 				}
1972 				if (++scontext >= first_scontext +
1973 						  vl_scontexts[i])
1974 					/* wrap back to first send context */
1975 					scontext = first_scontext;
1976 			}
1977 		} else {
1978 			/* just re-use entry without allocating */
1979 			newmap->map[i] = newmap->map[i % num_vls];
1980 		}
1981 		scontext = first_scontext + vl_scontexts[i];
1982 	}
1983 	/* newmap in hand, save old map */
1984 	spin_lock_irq(&dd->pio_map_lock);
1985 	oldmap = rcu_dereference_protected(dd->pio_map,
1986 					   lockdep_is_held(&dd->pio_map_lock));
1987 
1988 	/* publish newmap */
1989 	rcu_assign_pointer(dd->pio_map, newmap);
1990 
1991 	spin_unlock_irq(&dd->pio_map_lock);
1992 	/* success, free any old map after grace period */
1993 	if (oldmap)
1994 		call_rcu(&oldmap->list, pio_map_rcu_callback);
1995 	return 0;
1996 bail:
1997 	/* free any partial allocation */
1998 	pio_map_free(newmap);
1999 	return -ENOMEM;
2000 }
2001 
free_pio_map(struct hfi1_devdata * dd)2002 void free_pio_map(struct hfi1_devdata *dd)
2003 {
2004 	/* Free PIO map if allocated */
2005 	if (rcu_access_pointer(dd->pio_map)) {
2006 		spin_lock_irq(&dd->pio_map_lock);
2007 		pio_map_free(rcu_access_pointer(dd->pio_map));
2008 		RCU_INIT_POINTER(dd->pio_map, NULL);
2009 		spin_unlock_irq(&dd->pio_map_lock);
2010 		synchronize_rcu();
2011 	}
2012 	kfree(dd->kernel_send_context);
2013 	dd->kernel_send_context = NULL;
2014 }
2015 
init_pervl_scs(struct hfi1_devdata * dd)2016 int init_pervl_scs(struct hfi1_devdata *dd)
2017 {
2018 	int i;
2019 	u64 mask, all_vl_mask = (u64)0x80ff; /* VLs 0-7, 15 */
2020 	u64 data_vls_mask = (u64)0x00ff; /* VLs 0-7 */
2021 	u32 ctxt;
2022 	struct hfi1_pportdata *ppd = dd->pport;
2023 
2024 	dd->vld[15].sc = sc_alloc(dd, SC_VL15,
2025 				  dd->rcd[0]->rcvhdrqentsize, dd->node);
2026 	if (!dd->vld[15].sc)
2027 		return -ENOMEM;
2028 
2029 	hfi1_init_ctxt(dd->vld[15].sc);
2030 	dd->vld[15].mtu = enum_to_mtu(OPA_MTU_2048);
2031 
2032 	dd->kernel_send_context = kcalloc_node(dd->num_send_contexts,
2033 					       sizeof(struct send_context *),
2034 					       GFP_KERNEL, dd->node);
2035 	if (!dd->kernel_send_context)
2036 		goto freesc15;
2037 
2038 	dd->kernel_send_context[0] = dd->vld[15].sc;
2039 
2040 	for (i = 0; i < num_vls; i++) {
2041 		/*
2042 		 * Since this function does not deal with a specific
2043 		 * receive context but we need the RcvHdrQ entry size,
2044 		 * use the size from rcd[0]. It is guaranteed to be
2045 		 * valid at this point and will remain the same for all
2046 		 * receive contexts.
2047 		 */
2048 		dd->vld[i].sc = sc_alloc(dd, SC_KERNEL,
2049 					 dd->rcd[0]->rcvhdrqentsize, dd->node);
2050 		if (!dd->vld[i].sc)
2051 			goto nomem;
2052 		dd->kernel_send_context[i + 1] = dd->vld[i].sc;
2053 		hfi1_init_ctxt(dd->vld[i].sc);
2054 		/* non VL15 start with the max MTU */
2055 		dd->vld[i].mtu = hfi1_max_mtu;
2056 	}
2057 	for (i = num_vls; i < INIT_SC_PER_VL * num_vls; i++) {
2058 		dd->kernel_send_context[i + 1] =
2059 		sc_alloc(dd, SC_KERNEL, dd->rcd[0]->rcvhdrqentsize, dd->node);
2060 		if (!dd->kernel_send_context[i + 1])
2061 			goto nomem;
2062 		hfi1_init_ctxt(dd->kernel_send_context[i + 1]);
2063 	}
2064 
2065 	sc_enable(dd->vld[15].sc);
2066 	ctxt = dd->vld[15].sc->hw_context;
2067 	mask = all_vl_mask & ~(1LL << 15);
2068 	write_kctxt_csr(dd, ctxt, SC(CHECK_VL), mask);
2069 	dd_dev_info(dd,
2070 		    "Using send context %u(%u) for VL15\n",
2071 		    dd->vld[15].sc->sw_index, ctxt);
2072 
2073 	for (i = 0; i < num_vls; i++) {
2074 		sc_enable(dd->vld[i].sc);
2075 		ctxt = dd->vld[i].sc->hw_context;
2076 		mask = all_vl_mask & ~(data_vls_mask);
2077 		write_kctxt_csr(dd, ctxt, SC(CHECK_VL), mask);
2078 	}
2079 	for (i = num_vls; i < INIT_SC_PER_VL * num_vls; i++) {
2080 		sc_enable(dd->kernel_send_context[i + 1]);
2081 		ctxt = dd->kernel_send_context[i + 1]->hw_context;
2082 		mask = all_vl_mask & ~(data_vls_mask);
2083 		write_kctxt_csr(dd, ctxt, SC(CHECK_VL), mask);
2084 	}
2085 
2086 	if (pio_map_init(dd, ppd->port - 1, num_vls, NULL))
2087 		goto nomem;
2088 	return 0;
2089 
2090 nomem:
2091 	for (i = 0; i < num_vls; i++) {
2092 		sc_free(dd->vld[i].sc);
2093 		dd->vld[i].sc = NULL;
2094 	}
2095 
2096 	for (i = num_vls; i < INIT_SC_PER_VL * num_vls; i++)
2097 		sc_free(dd->kernel_send_context[i + 1]);
2098 
2099 	kfree(dd->kernel_send_context);
2100 	dd->kernel_send_context = NULL;
2101 
2102 freesc15:
2103 	sc_free(dd->vld[15].sc);
2104 	return -ENOMEM;
2105 }
2106 
init_credit_return(struct hfi1_devdata * dd)2107 int init_credit_return(struct hfi1_devdata *dd)
2108 {
2109 	int ret;
2110 	int i;
2111 
2112 	dd->cr_base = kcalloc(
2113 		node_affinity.num_possible_nodes,
2114 		sizeof(struct credit_return_base),
2115 		GFP_KERNEL);
2116 	if (!dd->cr_base) {
2117 		ret = -ENOMEM;
2118 		goto done;
2119 	}
2120 	for_each_node_with_cpus(i) {
2121 		int bytes = TXE_NUM_CONTEXTS * sizeof(struct credit_return);
2122 
2123 		set_dev_node(&dd->pcidev->dev, i);
2124 		dd->cr_base[i].va = dma_alloc_coherent(&dd->pcidev->dev,
2125 						       bytes,
2126 						       &dd->cr_base[i].dma,
2127 						       GFP_KERNEL);
2128 		if (!dd->cr_base[i].va) {
2129 			set_dev_node(&dd->pcidev->dev, dd->node);
2130 			dd_dev_err(dd,
2131 				   "Unable to allocate credit return DMA range for NUMA %d\n",
2132 				   i);
2133 			ret = -ENOMEM;
2134 			goto done;
2135 		}
2136 	}
2137 	set_dev_node(&dd->pcidev->dev, dd->node);
2138 
2139 	ret = 0;
2140 done:
2141 	return ret;
2142 }
2143 
free_credit_return(struct hfi1_devdata * dd)2144 void free_credit_return(struct hfi1_devdata *dd)
2145 {
2146 	int i;
2147 
2148 	if (!dd->cr_base)
2149 		return;
2150 	for (i = 0; i < node_affinity.num_possible_nodes; i++) {
2151 		if (dd->cr_base[i].va) {
2152 			dma_free_coherent(&dd->pcidev->dev,
2153 					  TXE_NUM_CONTEXTS *
2154 					  sizeof(struct credit_return),
2155 					  dd->cr_base[i].va,
2156 					  dd->cr_base[i].dma);
2157 		}
2158 	}
2159 	kfree(dd->cr_base);
2160 	dd->cr_base = NULL;
2161 }
2162 
seqfile_dump_sci(struct seq_file * s,u32 i,struct send_context_info * sci)2163 void seqfile_dump_sci(struct seq_file *s, u32 i,
2164 		      struct send_context_info *sci)
2165 {
2166 	struct send_context *sc = sci->sc;
2167 	u64 reg;
2168 
2169 	seq_printf(s, "SCI %u: type %u base %u credits %u\n",
2170 		   i, sci->type, sci->base, sci->credits);
2171 	seq_printf(s, "  flags 0x%x sw_inx %u hw_ctxt %u grp %u\n",
2172 		   sc->flags,  sc->sw_index, sc->hw_context, sc->group);
2173 	seq_printf(s, "  sr_size %u credits %u sr_head %u sr_tail %u\n",
2174 		   sc->sr_size, sc->credits, sc->sr_head, sc->sr_tail);
2175 	seq_printf(s, "  fill %lu free %lu fill_wrap %u alloc_free %lu\n",
2176 		   sc->fill, sc->free, sc->fill_wrap, sc->alloc_free);
2177 	seq_printf(s, "  credit_intr_count %u credit_ctrl 0x%llx\n",
2178 		   sc->credit_intr_count, sc->credit_ctrl);
2179 	reg = read_kctxt_csr(sc->dd, sc->hw_context, SC(CREDIT_STATUS));
2180 	seq_printf(s, "  *hw_free %llu CurrentFree %llu LastReturned %llu\n",
2181 		   (le64_to_cpu(*sc->hw_free) & CR_COUNTER_SMASK) >>
2182 		    CR_COUNTER_SHIFT,
2183 		   (reg >> SC(CREDIT_STATUS_CURRENT_FREE_COUNTER_SHIFT)) &
2184 		    SC(CREDIT_STATUS_CURRENT_FREE_COUNTER_MASK),
2185 		   reg & SC(CREDIT_STATUS_LAST_RETURNED_COUNTER_SMASK));
2186 }
2187