1 // SPDX-License-Identifier: GPL-2.0 or BSD-3-Clause
2 /*
3  * Copyright(c) 2015-2018 Intel Corporation.
4  */
5 
6 #include <linux/delay.h>
7 #include "hfi.h"
8 #include "qp.h"
9 #include "trace.h"
10 
11 #define SC(name) SEND_CTXT_##name
12 /*
13  * Send Context functions
14  */
15 static void sc_wait_for_packet_egress(struct send_context *sc, int pause);
16 
17 /*
18  * Set the CM reset bit and wait for it to clear.  Use the provided
19  * sendctrl register.  This routine has no locking.
20  */
__cm_reset(struct hfi1_devdata * dd,u64 sendctrl)21 void __cm_reset(struct hfi1_devdata *dd, u64 sendctrl)
22 {
23 	write_csr(dd, SEND_CTRL, sendctrl | SEND_CTRL_CM_RESET_SMASK);
24 	while (1) {
25 		udelay(1);
26 		sendctrl = read_csr(dd, SEND_CTRL);
27 		if ((sendctrl & SEND_CTRL_CM_RESET_SMASK) == 0)
28 			break;
29 	}
30 }
31 
32 /* global control of PIO send */
pio_send_control(struct hfi1_devdata * dd,int op)33 void pio_send_control(struct hfi1_devdata *dd, int op)
34 {
35 	u64 reg, mask;
36 	unsigned long flags;
37 	int write = 1;	/* write sendctrl back */
38 	int flush = 0;	/* re-read sendctrl to make sure it is flushed */
39 	int i;
40 
41 	spin_lock_irqsave(&dd->sendctrl_lock, flags);
42 
43 	reg = read_csr(dd, SEND_CTRL);
44 	switch (op) {
45 	case PSC_GLOBAL_ENABLE:
46 		reg |= SEND_CTRL_SEND_ENABLE_SMASK;
47 		fallthrough;
48 	case PSC_DATA_VL_ENABLE:
49 		mask = 0;
50 		for (i = 0; i < ARRAY_SIZE(dd->vld); i++)
51 			if (!dd->vld[i].mtu)
52 				mask |= BIT_ULL(i);
53 		/* Disallow sending on VLs not enabled */
54 		mask = (mask & SEND_CTRL_UNSUPPORTED_VL_MASK) <<
55 			SEND_CTRL_UNSUPPORTED_VL_SHIFT;
56 		reg = (reg & ~SEND_CTRL_UNSUPPORTED_VL_SMASK) | mask;
57 		break;
58 	case PSC_GLOBAL_DISABLE:
59 		reg &= ~SEND_CTRL_SEND_ENABLE_SMASK;
60 		break;
61 	case PSC_GLOBAL_VLARB_ENABLE:
62 		reg |= SEND_CTRL_VL_ARBITER_ENABLE_SMASK;
63 		break;
64 	case PSC_GLOBAL_VLARB_DISABLE:
65 		reg &= ~SEND_CTRL_VL_ARBITER_ENABLE_SMASK;
66 		break;
67 	case PSC_CM_RESET:
68 		__cm_reset(dd, reg);
69 		write = 0; /* CSR already written (and flushed) */
70 		break;
71 	case PSC_DATA_VL_DISABLE:
72 		reg |= SEND_CTRL_UNSUPPORTED_VL_SMASK;
73 		flush = 1;
74 		break;
75 	default:
76 		dd_dev_err(dd, "%s: invalid control %d\n", __func__, op);
77 		break;
78 	}
79 
80 	if (write) {
81 		write_csr(dd, SEND_CTRL, reg);
82 		if (flush)
83 			(void)read_csr(dd, SEND_CTRL); /* flush write */
84 	}
85 
86 	spin_unlock_irqrestore(&dd->sendctrl_lock, flags);
87 }
88 
89 /* number of send context memory pools */
90 #define NUM_SC_POOLS 2
91 
92 /* Send Context Size (SCS) wildcards */
93 #define SCS_POOL_0 -1
94 #define SCS_POOL_1 -2
95 
96 /* Send Context Count (SCC) wildcards */
97 #define SCC_PER_VL -1
98 #define SCC_PER_CPU  -2
99 #define SCC_PER_KRCVQ  -3
100 
101 /* Send Context Size (SCS) constants */
102 #define SCS_ACK_CREDITS  32
103 #define SCS_VL15_CREDITS 102	/* 3 pkts of 2048B data + 128B header */
104 
105 #define PIO_THRESHOLD_CEILING 4096
106 
107 #define PIO_WAIT_BATCH_SIZE 5
108 
109 /* default send context sizes */
110 static struct sc_config_sizes sc_config_sizes[SC_MAX] = {
111 	[SC_KERNEL] = { .size  = SCS_POOL_0,	/* even divide, pool 0 */
112 			.count = SCC_PER_VL },	/* one per NUMA */
113 	[SC_ACK]    = { .size  = SCS_ACK_CREDITS,
114 			.count = SCC_PER_KRCVQ },
115 	[SC_USER]   = { .size  = SCS_POOL_0,	/* even divide, pool 0 */
116 			.count = SCC_PER_CPU },	/* one per CPU */
117 	[SC_VL15]   = { .size  = SCS_VL15_CREDITS,
118 			.count = 1 },
119 
120 };
121 
122 /* send context memory pool configuration */
123 struct mem_pool_config {
124 	int centipercent;	/* % of memory, in 100ths of 1% */
125 	int absolute_blocks;	/* absolute block count */
126 };
127 
128 /* default memory pool configuration: 100% in pool 0 */
129 static struct mem_pool_config sc_mem_pool_config[NUM_SC_POOLS] = {
130 	/* centi%, abs blocks */
131 	{  10000,     -1 },		/* pool 0 */
132 	{      0,     -1 },		/* pool 1 */
133 };
134 
135 /* memory pool information, used when calculating final sizes */
136 struct mem_pool_info {
137 	int centipercent;	/*
138 				 * 100th of 1% of memory to use, -1 if blocks
139 				 * already set
140 				 */
141 	int count;		/* count of contexts in the pool */
142 	int blocks;		/* block size of the pool */
143 	int size;		/* context size, in blocks */
144 };
145 
146 /*
147  * Convert a pool wildcard to a valid pool index.  The wildcards
148  * start at -1 and increase negatively.  Map them as:
149  *	-1 => 0
150  *	-2 => 1
151  *	etc.
152  *
153  * Return -1 on non-wildcard input, otherwise convert to a pool number.
154  */
wildcard_to_pool(int wc)155 static int wildcard_to_pool(int wc)
156 {
157 	if (wc >= 0)
158 		return -1;	/* non-wildcard */
159 	return -wc - 1;
160 }
161 
162 static const char *sc_type_names[SC_MAX] = {
163 	"kernel",
164 	"ack",
165 	"user",
166 	"vl15"
167 };
168 
sc_type_name(int index)169 static const char *sc_type_name(int index)
170 {
171 	if (index < 0 || index >= SC_MAX)
172 		return "unknown";
173 	return sc_type_names[index];
174 }
175 
176 /*
177  * Read the send context memory pool configuration and send context
178  * size configuration.  Replace any wildcards and come up with final
179  * counts and sizes for the send context types.
180  */
init_sc_pools_and_sizes(struct hfi1_devdata * dd)181 int init_sc_pools_and_sizes(struct hfi1_devdata *dd)
182 {
183 	struct mem_pool_info mem_pool_info[NUM_SC_POOLS] = { { 0 } };
184 	int total_blocks = (chip_pio_mem_size(dd) / PIO_BLOCK_SIZE) - 1;
185 	int total_contexts = 0;
186 	int fixed_blocks;
187 	int pool_blocks;
188 	int used_blocks;
189 	int cp_total;		/* centipercent total */
190 	int ab_total;		/* absolute block total */
191 	int extra;
192 	int i;
193 
194 	/*
195 	 * When SDMA is enabled, kernel context pio packet size is capped by
196 	 * "piothreshold". Reduce pio buffer allocation for kernel context by
197 	 * setting it to a fixed size. The allocation allows 3-deep buffering
198 	 * of the largest pio packets plus up to 128 bytes header, sufficient
199 	 * to maintain verbs performance.
200 	 *
201 	 * When SDMA is disabled, keep the default pooling allocation.
202 	 */
203 	if (HFI1_CAP_IS_KSET(SDMA)) {
204 		u16 max_pkt_size = (piothreshold < PIO_THRESHOLD_CEILING) ?
205 					 piothreshold : PIO_THRESHOLD_CEILING;
206 		sc_config_sizes[SC_KERNEL].size =
207 			3 * (max_pkt_size + 128) / PIO_BLOCK_SIZE;
208 	}
209 
210 	/*
211 	 * Step 0:
212 	 *	- copy the centipercents/absolute sizes from the pool config
213 	 *	- sanity check these values
214 	 *	- add up centipercents, then later check for full value
215 	 *	- add up absolute blocks, then later check for over-commit
216 	 */
217 	cp_total = 0;
218 	ab_total = 0;
219 	for (i = 0; i < NUM_SC_POOLS; i++) {
220 		int cp = sc_mem_pool_config[i].centipercent;
221 		int ab = sc_mem_pool_config[i].absolute_blocks;
222 
223 		/*
224 		 * A negative value is "unused" or "invalid".  Both *can*
225 		 * be valid, but centipercent wins, so check that first
226 		 */
227 		if (cp >= 0) {			/* centipercent valid */
228 			cp_total += cp;
229 		} else if (ab >= 0) {		/* absolute blocks valid */
230 			ab_total += ab;
231 		} else {			/* neither valid */
232 			dd_dev_err(
233 				dd,
234 				"Send context memory pool %d: both the block count and centipercent are invalid\n",
235 				i);
236 			return -EINVAL;
237 		}
238 
239 		mem_pool_info[i].centipercent = cp;
240 		mem_pool_info[i].blocks = ab;
241 	}
242 
243 	/* do not use both % and absolute blocks for different pools */
244 	if (cp_total != 0 && ab_total != 0) {
245 		dd_dev_err(
246 			dd,
247 			"All send context memory pools must be described as either centipercent or blocks, no mixing between pools\n");
248 		return -EINVAL;
249 	}
250 
251 	/* if any percentages are present, they must add up to 100% x 100 */
252 	if (cp_total != 0 && cp_total != 10000) {
253 		dd_dev_err(
254 			dd,
255 			"Send context memory pool centipercent is %d, expecting 10000\n",
256 			cp_total);
257 		return -EINVAL;
258 	}
259 
260 	/* the absolute pool total cannot be more than the mem total */
261 	if (ab_total > total_blocks) {
262 		dd_dev_err(
263 			dd,
264 			"Send context memory pool absolute block count %d is larger than the memory size %d\n",
265 			ab_total, total_blocks);
266 		return -EINVAL;
267 	}
268 
269 	/*
270 	 * Step 2:
271 	 *	- copy from the context size config
272 	 *	- replace context type wildcard counts with real values
273 	 *	- add up non-memory pool block sizes
274 	 *	- add up memory pool user counts
275 	 */
276 	fixed_blocks = 0;
277 	for (i = 0; i < SC_MAX; i++) {
278 		int count = sc_config_sizes[i].count;
279 		int size = sc_config_sizes[i].size;
280 		int pool;
281 
282 		/*
283 		 * Sanity check count: Either a positive value or
284 		 * one of the expected wildcards is valid.  The positive
285 		 * value is checked later when we compare against total
286 		 * memory available.
287 		 */
288 		if (i == SC_ACK) {
289 			count = dd->n_krcv_queues;
290 		} else if (i == SC_KERNEL) {
291 			count = INIT_SC_PER_VL * num_vls;
292 		} else if (count == SCC_PER_CPU) {
293 			count = dd->num_rcv_contexts - dd->n_krcv_queues;
294 		} else if (count < 0) {
295 			dd_dev_err(
296 				dd,
297 				"%s send context invalid count wildcard %d\n",
298 				sc_type_name(i), count);
299 			return -EINVAL;
300 		}
301 		if (total_contexts + count > chip_send_contexts(dd))
302 			count = chip_send_contexts(dd) - total_contexts;
303 
304 		total_contexts += count;
305 
306 		/*
307 		 * Sanity check pool: The conversion will return a pool
308 		 * number or -1 if a fixed (non-negative) value.  The fixed
309 		 * value is checked later when we compare against
310 		 * total memory available.
311 		 */
312 		pool = wildcard_to_pool(size);
313 		if (pool == -1) {			/* non-wildcard */
314 			fixed_blocks += size * count;
315 		} else if (pool < NUM_SC_POOLS) {	/* valid wildcard */
316 			mem_pool_info[pool].count += count;
317 		} else {				/* invalid wildcard */
318 			dd_dev_err(
319 				dd,
320 				"%s send context invalid pool wildcard %d\n",
321 				sc_type_name(i), size);
322 			return -EINVAL;
323 		}
324 
325 		dd->sc_sizes[i].count = count;
326 		dd->sc_sizes[i].size = size;
327 	}
328 	if (fixed_blocks > total_blocks) {
329 		dd_dev_err(
330 			dd,
331 			"Send context fixed block count, %u, larger than total block count %u\n",
332 			fixed_blocks, total_blocks);
333 		return -EINVAL;
334 	}
335 
336 	/* step 3: calculate the blocks in the pools, and pool context sizes */
337 	pool_blocks = total_blocks - fixed_blocks;
338 	if (ab_total > pool_blocks) {
339 		dd_dev_err(
340 			dd,
341 			"Send context fixed pool sizes, %u, larger than pool block count %u\n",
342 			ab_total, pool_blocks);
343 		return -EINVAL;
344 	}
345 	/* subtract off the fixed pool blocks */
346 	pool_blocks -= ab_total;
347 
348 	for (i = 0; i < NUM_SC_POOLS; i++) {
349 		struct mem_pool_info *pi = &mem_pool_info[i];
350 
351 		/* % beats absolute blocks */
352 		if (pi->centipercent >= 0)
353 			pi->blocks = (pool_blocks * pi->centipercent) / 10000;
354 
355 		if (pi->blocks == 0 && pi->count != 0) {
356 			dd_dev_err(
357 				dd,
358 				"Send context memory pool %d has %u contexts, but no blocks\n",
359 				i, pi->count);
360 			return -EINVAL;
361 		}
362 		if (pi->count == 0) {
363 			/* warn about wasted blocks */
364 			if (pi->blocks != 0)
365 				dd_dev_err(
366 					dd,
367 					"Send context memory pool %d has %u blocks, but zero contexts\n",
368 					i, pi->blocks);
369 			pi->size = 0;
370 		} else {
371 			pi->size = pi->blocks / pi->count;
372 		}
373 	}
374 
375 	/* step 4: fill in the context type sizes from the pool sizes */
376 	used_blocks = 0;
377 	for (i = 0; i < SC_MAX; i++) {
378 		if (dd->sc_sizes[i].size < 0) {
379 			unsigned pool = wildcard_to_pool(dd->sc_sizes[i].size);
380 
381 			WARN_ON_ONCE(pool >= NUM_SC_POOLS);
382 			dd->sc_sizes[i].size = mem_pool_info[pool].size;
383 		}
384 		/* make sure we are not larger than what is allowed by the HW */
385 #define PIO_MAX_BLOCKS 1024
386 		if (dd->sc_sizes[i].size > PIO_MAX_BLOCKS)
387 			dd->sc_sizes[i].size = PIO_MAX_BLOCKS;
388 
389 		/* calculate our total usage */
390 		used_blocks += dd->sc_sizes[i].size * dd->sc_sizes[i].count;
391 	}
392 	extra = total_blocks - used_blocks;
393 	if (extra != 0)
394 		dd_dev_info(dd, "unused send context blocks: %d\n", extra);
395 
396 	return total_contexts;
397 }
398 
init_send_contexts(struct hfi1_devdata * dd)399 int init_send_contexts(struct hfi1_devdata *dd)
400 {
401 	u16 base;
402 	int ret, i, j, context;
403 
404 	ret = init_credit_return(dd);
405 	if (ret)
406 		return ret;
407 
408 	dd->hw_to_sw = kmalloc_array(TXE_NUM_CONTEXTS, sizeof(u8),
409 					GFP_KERNEL);
410 	dd->send_contexts = kcalloc(dd->num_send_contexts,
411 				    sizeof(struct send_context_info),
412 				    GFP_KERNEL);
413 	if (!dd->send_contexts || !dd->hw_to_sw) {
414 		kfree(dd->hw_to_sw);
415 		kfree(dd->send_contexts);
416 		free_credit_return(dd);
417 		return -ENOMEM;
418 	}
419 
420 	/* hardware context map starts with invalid send context indices */
421 	for (i = 0; i < TXE_NUM_CONTEXTS; i++)
422 		dd->hw_to_sw[i] = INVALID_SCI;
423 
424 	/*
425 	 * All send contexts have their credit sizes.  Allocate credits
426 	 * for each context one after another from the global space.
427 	 */
428 	context = 0;
429 	base = 1;
430 	for (i = 0; i < SC_MAX; i++) {
431 		struct sc_config_sizes *scs = &dd->sc_sizes[i];
432 
433 		for (j = 0; j < scs->count; j++) {
434 			struct send_context_info *sci =
435 						&dd->send_contexts[context];
436 			sci->type = i;
437 			sci->base = base;
438 			sci->credits = scs->size;
439 
440 			context++;
441 			base += scs->size;
442 		}
443 	}
444 
445 	return 0;
446 }
447 
448 /*
449  * Allocate a software index and hardware context of the given type.
450  *
451  * Must be called with dd->sc_lock held.
452  */
sc_hw_alloc(struct hfi1_devdata * dd,int type,u32 * sw_index,u32 * hw_context)453 static int sc_hw_alloc(struct hfi1_devdata *dd, int type, u32 *sw_index,
454 		       u32 *hw_context)
455 {
456 	struct send_context_info *sci;
457 	u32 index;
458 	u32 context;
459 
460 	for (index = 0, sci = &dd->send_contexts[0];
461 			index < dd->num_send_contexts; index++, sci++) {
462 		if (sci->type == type && sci->allocated == 0) {
463 			sci->allocated = 1;
464 			/* use a 1:1 mapping, but make them non-equal */
465 			context = chip_send_contexts(dd) - index - 1;
466 			dd->hw_to_sw[context] = index;
467 			*sw_index = index;
468 			*hw_context = context;
469 			return 0; /* success */
470 		}
471 	}
472 	dd_dev_err(dd, "Unable to locate a free type %d send context\n", type);
473 	return -ENOSPC;
474 }
475 
476 /*
477  * Free the send context given by its software index.
478  *
479  * Must be called with dd->sc_lock held.
480  */
sc_hw_free(struct hfi1_devdata * dd,u32 sw_index,u32 hw_context)481 static void sc_hw_free(struct hfi1_devdata *dd, u32 sw_index, u32 hw_context)
482 {
483 	struct send_context_info *sci;
484 
485 	sci = &dd->send_contexts[sw_index];
486 	if (!sci->allocated) {
487 		dd_dev_err(dd, "%s: sw_index %u not allocated? hw_context %u\n",
488 			   __func__, sw_index, hw_context);
489 	}
490 	sci->allocated = 0;
491 	dd->hw_to_sw[hw_context] = INVALID_SCI;
492 }
493 
494 /* return the base context of a context in a group */
group_context(u32 context,u32 group)495 static inline u32 group_context(u32 context, u32 group)
496 {
497 	return (context >> group) << group;
498 }
499 
500 /* return the size of a group */
group_size(u32 group)501 static inline u32 group_size(u32 group)
502 {
503 	return 1 << group;
504 }
505 
506 /*
507  * Obtain the credit return addresses, kernel virtual and bus, for the
508  * given sc.
509  *
510  * To understand this routine:
511  * o va and dma are arrays of struct credit_return.  One for each physical
512  *   send context, per NUMA.
513  * o Each send context always looks in its relative location in a struct
514  *   credit_return for its credit return.
515  * o Each send context in a group must have its return address CSR programmed
516  *   with the same value.  Use the address of the first send context in the
517  *   group.
518  */
cr_group_addresses(struct send_context * sc,dma_addr_t * dma)519 static void cr_group_addresses(struct send_context *sc, dma_addr_t *dma)
520 {
521 	u32 gc = group_context(sc->hw_context, sc->group);
522 	u32 index = sc->hw_context & 0x7;
523 
524 	sc->hw_free = &sc->dd->cr_base[sc->node].va[gc].cr[index];
525 	*dma = (unsigned long)
526 	       &((struct credit_return *)sc->dd->cr_base[sc->node].dma)[gc];
527 }
528 
529 /*
530  * Work queue function triggered in error interrupt routine for
531  * kernel contexts.
532  */
sc_halted(struct work_struct * work)533 static void sc_halted(struct work_struct *work)
534 {
535 	struct send_context *sc;
536 
537 	sc = container_of(work, struct send_context, halt_work);
538 	sc_restart(sc);
539 }
540 
541 /*
542  * Calculate PIO block threshold for this send context using the given MTU.
543  * Trigger a return when one MTU plus optional header of credits remain.
544  *
545  * Parameter mtu is in bytes.
546  * Parameter hdrqentsize is in DWORDs.
547  *
548  * Return value is what to write into the CSR: trigger return when
549  * unreturned credits pass this count.
550  */
sc_mtu_to_threshold(struct send_context * sc,u32 mtu,u32 hdrqentsize)551 u32 sc_mtu_to_threshold(struct send_context *sc, u32 mtu, u32 hdrqentsize)
552 {
553 	u32 release_credits;
554 	u32 threshold;
555 
556 	/* add in the header size, then divide by the PIO block size */
557 	mtu += hdrqentsize << 2;
558 	release_credits = DIV_ROUND_UP(mtu, PIO_BLOCK_SIZE);
559 
560 	/* check against this context's credits */
561 	if (sc->credits <= release_credits)
562 		threshold = 1;
563 	else
564 		threshold = sc->credits - release_credits;
565 
566 	return threshold;
567 }
568 
569 /*
570  * Calculate credit threshold in terms of percent of the allocated credits.
571  * Trigger when unreturned credits equal or exceed the percentage of the whole.
572  *
573  * Return value is what to write into the CSR: trigger return when
574  * unreturned credits pass this count.
575  */
sc_percent_to_threshold(struct send_context * sc,u32 percent)576 u32 sc_percent_to_threshold(struct send_context *sc, u32 percent)
577 {
578 	return (sc->credits * percent) / 100;
579 }
580 
581 /*
582  * Set the credit return threshold.
583  */
sc_set_cr_threshold(struct send_context * sc,u32 new_threshold)584 void sc_set_cr_threshold(struct send_context *sc, u32 new_threshold)
585 {
586 	unsigned long flags;
587 	u32 old_threshold;
588 	int force_return = 0;
589 
590 	spin_lock_irqsave(&sc->credit_ctrl_lock, flags);
591 
592 	old_threshold = (sc->credit_ctrl >>
593 				SC(CREDIT_CTRL_THRESHOLD_SHIFT))
594 			 & SC(CREDIT_CTRL_THRESHOLD_MASK);
595 
596 	if (new_threshold != old_threshold) {
597 		sc->credit_ctrl =
598 			(sc->credit_ctrl
599 				& ~SC(CREDIT_CTRL_THRESHOLD_SMASK))
600 			| ((new_threshold
601 				& SC(CREDIT_CTRL_THRESHOLD_MASK))
602 			   << SC(CREDIT_CTRL_THRESHOLD_SHIFT));
603 		write_kctxt_csr(sc->dd, sc->hw_context,
604 				SC(CREDIT_CTRL), sc->credit_ctrl);
605 
606 		/* force a credit return on change to avoid a possible stall */
607 		force_return = 1;
608 	}
609 
610 	spin_unlock_irqrestore(&sc->credit_ctrl_lock, flags);
611 
612 	if (force_return)
613 		sc_return_credits(sc);
614 }
615 
616 /*
617  * set_pio_integrity
618  *
619  * Set the CHECK_ENABLE register for the send context 'sc'.
620  */
set_pio_integrity(struct send_context * sc)621 void set_pio_integrity(struct send_context *sc)
622 {
623 	struct hfi1_devdata *dd = sc->dd;
624 	u32 hw_context = sc->hw_context;
625 	int type = sc->type;
626 
627 	write_kctxt_csr(dd, hw_context,
628 			SC(CHECK_ENABLE),
629 			hfi1_pkt_default_send_ctxt_mask(dd, type));
630 }
631 
get_buffers_allocated(struct send_context * sc)632 static u32 get_buffers_allocated(struct send_context *sc)
633 {
634 	int cpu;
635 	u32 ret = 0;
636 
637 	for_each_possible_cpu(cpu)
638 		ret += *per_cpu_ptr(sc->buffers_allocated, cpu);
639 	return ret;
640 }
641 
reset_buffers_allocated(struct send_context * sc)642 static void reset_buffers_allocated(struct send_context *sc)
643 {
644 	int cpu;
645 
646 	for_each_possible_cpu(cpu)
647 		(*per_cpu_ptr(sc->buffers_allocated, cpu)) = 0;
648 }
649 
650 /*
651  * Allocate a NUMA relative send context structure of the given type along
652  * with a HW context.
653  */
sc_alloc(struct hfi1_devdata * dd,int type,uint hdrqentsize,int numa)654 struct send_context *sc_alloc(struct hfi1_devdata *dd, int type,
655 			      uint hdrqentsize, int numa)
656 {
657 	struct send_context_info *sci;
658 	struct send_context *sc = NULL;
659 	dma_addr_t dma;
660 	unsigned long flags;
661 	u64 reg;
662 	u32 thresh;
663 	u32 sw_index;
664 	u32 hw_context;
665 	int ret;
666 	u8 opval, opmask;
667 
668 	/* do not allocate while frozen */
669 	if (dd->flags & HFI1_FROZEN)
670 		return NULL;
671 
672 	sc = kzalloc_node(sizeof(*sc), GFP_KERNEL, numa);
673 	if (!sc)
674 		return NULL;
675 
676 	sc->buffers_allocated = alloc_percpu(u32);
677 	if (!sc->buffers_allocated) {
678 		kfree(sc);
679 		dd_dev_err(dd,
680 			   "Cannot allocate buffers_allocated per cpu counters\n"
681 			  );
682 		return NULL;
683 	}
684 
685 	spin_lock_irqsave(&dd->sc_lock, flags);
686 	ret = sc_hw_alloc(dd, type, &sw_index, &hw_context);
687 	if (ret) {
688 		spin_unlock_irqrestore(&dd->sc_lock, flags);
689 		free_percpu(sc->buffers_allocated);
690 		kfree(sc);
691 		return NULL;
692 	}
693 
694 	sci = &dd->send_contexts[sw_index];
695 	sci->sc = sc;
696 
697 	sc->dd = dd;
698 	sc->node = numa;
699 	sc->type = type;
700 	spin_lock_init(&sc->alloc_lock);
701 	spin_lock_init(&sc->release_lock);
702 	spin_lock_init(&sc->credit_ctrl_lock);
703 	seqlock_init(&sc->waitlock);
704 	INIT_LIST_HEAD(&sc->piowait);
705 	INIT_WORK(&sc->halt_work, sc_halted);
706 	init_waitqueue_head(&sc->halt_wait);
707 
708 	/* grouping is always single context for now */
709 	sc->group = 0;
710 
711 	sc->sw_index = sw_index;
712 	sc->hw_context = hw_context;
713 	cr_group_addresses(sc, &dma);
714 	sc->credits = sci->credits;
715 	sc->size = sc->credits * PIO_BLOCK_SIZE;
716 
717 /* PIO Send Memory Address details */
718 #define PIO_ADDR_CONTEXT_MASK 0xfful
719 #define PIO_ADDR_CONTEXT_SHIFT 16
720 	sc->base_addr = dd->piobase + ((hw_context & PIO_ADDR_CONTEXT_MASK)
721 					<< PIO_ADDR_CONTEXT_SHIFT);
722 
723 	/* set base and credits */
724 	reg = ((sci->credits & SC(CTRL_CTXT_DEPTH_MASK))
725 					<< SC(CTRL_CTXT_DEPTH_SHIFT))
726 		| ((sci->base & SC(CTRL_CTXT_BASE_MASK))
727 					<< SC(CTRL_CTXT_BASE_SHIFT));
728 	write_kctxt_csr(dd, hw_context, SC(CTRL), reg);
729 
730 	set_pio_integrity(sc);
731 
732 	/* unmask all errors */
733 	write_kctxt_csr(dd, hw_context, SC(ERR_MASK), (u64)-1);
734 
735 	/* set the default partition key */
736 	write_kctxt_csr(dd, hw_context, SC(CHECK_PARTITION_KEY),
737 			(SC(CHECK_PARTITION_KEY_VALUE_MASK) &
738 			 DEFAULT_PKEY) <<
739 			SC(CHECK_PARTITION_KEY_VALUE_SHIFT));
740 
741 	/* per context type checks */
742 	if (type == SC_USER) {
743 		opval = USER_OPCODE_CHECK_VAL;
744 		opmask = USER_OPCODE_CHECK_MASK;
745 	} else {
746 		opval = OPCODE_CHECK_VAL_DISABLED;
747 		opmask = OPCODE_CHECK_MASK_DISABLED;
748 	}
749 
750 	/* set the send context check opcode mask and value */
751 	write_kctxt_csr(dd, hw_context, SC(CHECK_OPCODE),
752 			((u64)opmask << SC(CHECK_OPCODE_MASK_SHIFT)) |
753 			((u64)opval << SC(CHECK_OPCODE_VALUE_SHIFT)));
754 
755 	/* set up credit return */
756 	reg = dma & SC(CREDIT_RETURN_ADDR_ADDRESS_SMASK);
757 	write_kctxt_csr(dd, hw_context, SC(CREDIT_RETURN_ADDR), reg);
758 
759 	/*
760 	 * Calculate the initial credit return threshold.
761 	 *
762 	 * For Ack contexts, set a threshold for half the credits.
763 	 * For User contexts use the given percentage.  This has been
764 	 * sanitized on driver start-up.
765 	 * For Kernel contexts, use the default MTU plus a header
766 	 * or half the credits, whichever is smaller. This should
767 	 * work for both the 3-deep buffering allocation and the
768 	 * pooling allocation.
769 	 */
770 	if (type == SC_ACK) {
771 		thresh = sc_percent_to_threshold(sc, 50);
772 	} else if (type == SC_USER) {
773 		thresh = sc_percent_to_threshold(sc,
774 						 user_credit_return_threshold);
775 	} else { /* kernel */
776 		thresh = min(sc_percent_to_threshold(sc, 50),
777 			     sc_mtu_to_threshold(sc, hfi1_max_mtu,
778 						 hdrqentsize));
779 	}
780 	reg = thresh << SC(CREDIT_CTRL_THRESHOLD_SHIFT);
781 	/* add in early return */
782 	if (type == SC_USER && HFI1_CAP_IS_USET(EARLY_CREDIT_RETURN))
783 		reg |= SC(CREDIT_CTRL_EARLY_RETURN_SMASK);
784 	else if (HFI1_CAP_IS_KSET(EARLY_CREDIT_RETURN)) /* kernel, ack */
785 		reg |= SC(CREDIT_CTRL_EARLY_RETURN_SMASK);
786 
787 	/* set up write-through credit_ctrl */
788 	sc->credit_ctrl = reg;
789 	write_kctxt_csr(dd, hw_context, SC(CREDIT_CTRL), reg);
790 
791 	/* User send contexts should not allow sending on VL15 */
792 	if (type == SC_USER) {
793 		reg = 1ULL << 15;
794 		write_kctxt_csr(dd, hw_context, SC(CHECK_VL), reg);
795 	}
796 
797 	spin_unlock_irqrestore(&dd->sc_lock, flags);
798 
799 	/*
800 	 * Allocate shadow ring to track outstanding PIO buffers _after_
801 	 * unlocking.  We don't know the size until the lock is held and
802 	 * we can't allocate while the lock is held.  No one is using
803 	 * the context yet, so allocate it now.
804 	 *
805 	 * User contexts do not get a shadow ring.
806 	 */
807 	if (type != SC_USER) {
808 		/*
809 		 * Size the shadow ring 1 larger than the number of credits
810 		 * so head == tail can mean empty.
811 		 */
812 		sc->sr_size = sci->credits + 1;
813 		sc->sr = kcalloc_node(sc->sr_size,
814 				      sizeof(union pio_shadow_ring),
815 				      GFP_KERNEL, numa);
816 		if (!sc->sr) {
817 			sc_free(sc);
818 			return NULL;
819 		}
820 	}
821 
822 	hfi1_cdbg(PIO,
823 		  "Send context %u(%u) %s group %u credits %u credit_ctrl 0x%llx threshold %u\n",
824 		  sw_index,
825 		  hw_context,
826 		  sc_type_name(type),
827 		  sc->group,
828 		  sc->credits,
829 		  sc->credit_ctrl,
830 		  thresh);
831 
832 	return sc;
833 }
834 
835 /* free a per-NUMA send context structure */
sc_free(struct send_context * sc)836 void sc_free(struct send_context *sc)
837 {
838 	struct hfi1_devdata *dd;
839 	unsigned long flags;
840 	u32 sw_index;
841 	u32 hw_context;
842 
843 	if (!sc)
844 		return;
845 
846 	sc->flags |= SCF_IN_FREE;	/* ensure no restarts */
847 	dd = sc->dd;
848 	if (!list_empty(&sc->piowait))
849 		dd_dev_err(dd, "piowait list not empty!\n");
850 	sw_index = sc->sw_index;
851 	hw_context = sc->hw_context;
852 	sc_disable(sc);	/* make sure the HW is disabled */
853 	flush_work(&sc->halt_work);
854 
855 	spin_lock_irqsave(&dd->sc_lock, flags);
856 	dd->send_contexts[sw_index].sc = NULL;
857 
858 	/* clear/disable all registers set in sc_alloc */
859 	write_kctxt_csr(dd, hw_context, SC(CTRL), 0);
860 	write_kctxt_csr(dd, hw_context, SC(CHECK_ENABLE), 0);
861 	write_kctxt_csr(dd, hw_context, SC(ERR_MASK), 0);
862 	write_kctxt_csr(dd, hw_context, SC(CHECK_PARTITION_KEY), 0);
863 	write_kctxt_csr(dd, hw_context, SC(CHECK_OPCODE), 0);
864 	write_kctxt_csr(dd, hw_context, SC(CREDIT_RETURN_ADDR), 0);
865 	write_kctxt_csr(dd, hw_context, SC(CREDIT_CTRL), 0);
866 
867 	/* release the index and context for re-use */
868 	sc_hw_free(dd, sw_index, hw_context);
869 	spin_unlock_irqrestore(&dd->sc_lock, flags);
870 
871 	kfree(sc->sr);
872 	free_percpu(sc->buffers_allocated);
873 	kfree(sc);
874 }
875 
876 /* disable the context */
sc_disable(struct send_context * sc)877 void sc_disable(struct send_context *sc)
878 {
879 	u64 reg;
880 	struct pio_buf *pbuf;
881 	LIST_HEAD(wake_list);
882 
883 	if (!sc)
884 		return;
885 
886 	/* do all steps, even if already disabled */
887 	spin_lock_irq(&sc->alloc_lock);
888 	reg = read_kctxt_csr(sc->dd, sc->hw_context, SC(CTRL));
889 	reg &= ~SC(CTRL_CTXT_ENABLE_SMASK);
890 	sc->flags &= ~SCF_ENABLED;
891 	sc_wait_for_packet_egress(sc, 1);
892 	write_kctxt_csr(sc->dd, sc->hw_context, SC(CTRL), reg);
893 
894 	/*
895 	 * Flush any waiters.  Once the context is disabled,
896 	 * credit return interrupts are stopped (although there
897 	 * could be one in-process when the context is disabled).
898 	 * Wait one microsecond for any lingering interrupts, then
899 	 * proceed with the flush.
900 	 */
901 	udelay(1);
902 	spin_lock(&sc->release_lock);
903 	if (sc->sr) {	/* this context has a shadow ring */
904 		while (sc->sr_tail != sc->sr_head) {
905 			pbuf = &sc->sr[sc->sr_tail].pbuf;
906 			if (pbuf->cb)
907 				(*pbuf->cb)(pbuf->arg, PRC_SC_DISABLE);
908 			sc->sr_tail++;
909 			if (sc->sr_tail >= sc->sr_size)
910 				sc->sr_tail = 0;
911 		}
912 	}
913 	spin_unlock(&sc->release_lock);
914 
915 	write_seqlock(&sc->waitlock);
916 	if (!list_empty(&sc->piowait))
917 		list_move(&sc->piowait, &wake_list);
918 	write_sequnlock(&sc->waitlock);
919 	while (!list_empty(&wake_list)) {
920 		struct iowait *wait;
921 		struct rvt_qp *qp;
922 		struct hfi1_qp_priv *priv;
923 
924 		wait = list_first_entry(&wake_list, struct iowait, list);
925 		qp = iowait_to_qp(wait);
926 		priv = qp->priv;
927 		list_del_init(&priv->s_iowait.list);
928 		priv->s_iowait.lock = NULL;
929 		hfi1_qp_wakeup(qp, RVT_S_WAIT_PIO | HFI1_S_WAIT_PIO_DRAIN);
930 	}
931 
932 	spin_unlock_irq(&sc->alloc_lock);
933 }
934 
935 /* return SendEgressCtxtStatus.PacketOccupancy */
packet_occupancy(u64 reg)936 static u64 packet_occupancy(u64 reg)
937 {
938 	return (reg &
939 		SEND_EGRESS_CTXT_STATUS_CTXT_EGRESS_PACKET_OCCUPANCY_SMASK)
940 		>> SEND_EGRESS_CTXT_STATUS_CTXT_EGRESS_PACKET_OCCUPANCY_SHIFT;
941 }
942 
943 /* is egress halted on the context? */
egress_halted(u64 reg)944 static bool egress_halted(u64 reg)
945 {
946 	return !!(reg & SEND_EGRESS_CTXT_STATUS_CTXT_EGRESS_HALT_STATUS_SMASK);
947 }
948 
949 /* is the send context halted? */
is_sc_halted(struct hfi1_devdata * dd,u32 hw_context)950 static bool is_sc_halted(struct hfi1_devdata *dd, u32 hw_context)
951 {
952 	return !!(read_kctxt_csr(dd, hw_context, SC(STATUS)) &
953 		  SC(STATUS_CTXT_HALTED_SMASK));
954 }
955 
956 /**
957  * sc_wait_for_packet_egress - wait for packet
958  * @sc: valid send context
959  * @pause: wait for credit return
960  *
961  * Wait for packet egress, optionally pause for credit return
962  *
963  * Egress halt and Context halt are not necessarily the same thing, so
964  * check for both.
965  *
966  * NOTE: The context halt bit may not be set immediately.  Because of this,
967  * it is necessary to check the SW SFC_HALTED bit (set in the IRQ) and the HW
968  * context bit to determine if the context is halted.
969  */
sc_wait_for_packet_egress(struct send_context * sc,int pause)970 static void sc_wait_for_packet_egress(struct send_context *sc, int pause)
971 {
972 	struct hfi1_devdata *dd = sc->dd;
973 	u64 reg = 0;
974 	u64 reg_prev;
975 	u32 loop = 0;
976 
977 	while (1) {
978 		reg_prev = reg;
979 		reg = read_csr(dd, sc->hw_context * 8 +
980 			       SEND_EGRESS_CTXT_STATUS);
981 		/* done if any halt bits, SW or HW are set */
982 		if (sc->flags & SCF_HALTED ||
983 		    is_sc_halted(dd, sc->hw_context) || egress_halted(reg))
984 			break;
985 		reg = packet_occupancy(reg);
986 		if (reg == 0)
987 			break;
988 		/* counter is reset if occupancy count changes */
989 		if (reg != reg_prev)
990 			loop = 0;
991 		if (loop > 50000) {
992 			/* timed out - bounce the link */
993 			dd_dev_err(dd,
994 				   "%s: context %u(%u) timeout waiting for packets to egress, remaining count %u, bouncing link\n",
995 				   __func__, sc->sw_index,
996 				   sc->hw_context, (u32)reg);
997 			queue_work(dd->pport->link_wq,
998 				   &dd->pport->link_bounce_work);
999 			break;
1000 		}
1001 		loop++;
1002 		udelay(1);
1003 	}
1004 
1005 	if (pause)
1006 		/* Add additional delay to ensure chip returns all credits */
1007 		pause_for_credit_return(dd);
1008 }
1009 
sc_wait(struct hfi1_devdata * dd)1010 void sc_wait(struct hfi1_devdata *dd)
1011 {
1012 	int i;
1013 
1014 	for (i = 0; i < dd->num_send_contexts; i++) {
1015 		struct send_context *sc = dd->send_contexts[i].sc;
1016 
1017 		if (!sc)
1018 			continue;
1019 		sc_wait_for_packet_egress(sc, 0);
1020 	}
1021 }
1022 
1023 /*
1024  * Restart a context after it has been halted due to error.
1025  *
1026  * If the first step fails - wait for the halt to be asserted, return early.
1027  * Otherwise complain about timeouts but keep going.
1028  *
1029  * It is expected that allocations (enabled flag bit) have been shut off
1030  * already (only applies to kernel contexts).
1031  */
sc_restart(struct send_context * sc)1032 int sc_restart(struct send_context *sc)
1033 {
1034 	struct hfi1_devdata *dd = sc->dd;
1035 	u64 reg;
1036 	u32 loop;
1037 	int count;
1038 
1039 	/* bounce off if not halted, or being free'd */
1040 	if (!(sc->flags & SCF_HALTED) || (sc->flags & SCF_IN_FREE))
1041 		return -EINVAL;
1042 
1043 	dd_dev_info(dd, "restarting send context %u(%u)\n", sc->sw_index,
1044 		    sc->hw_context);
1045 
1046 	/*
1047 	 * Step 1: Wait for the context to actually halt.
1048 	 *
1049 	 * The error interrupt is asynchronous to actually setting halt
1050 	 * on the context.
1051 	 */
1052 	loop = 0;
1053 	while (1) {
1054 		reg = read_kctxt_csr(dd, sc->hw_context, SC(STATUS));
1055 		if (reg & SC(STATUS_CTXT_HALTED_SMASK))
1056 			break;
1057 		if (loop > 100) {
1058 			dd_dev_err(dd, "%s: context %u(%u) not halting, skipping\n",
1059 				   __func__, sc->sw_index, sc->hw_context);
1060 			return -ETIME;
1061 		}
1062 		loop++;
1063 		udelay(1);
1064 	}
1065 
1066 	/*
1067 	 * Step 2: Ensure no users are still trying to write to PIO.
1068 	 *
1069 	 * For kernel contexts, we have already turned off buffer allocation.
1070 	 * Now wait for the buffer count to go to zero.
1071 	 *
1072 	 * For user contexts, the user handling code has cut off write access
1073 	 * to the context's PIO pages before calling this routine and will
1074 	 * restore write access after this routine returns.
1075 	 */
1076 	if (sc->type != SC_USER) {
1077 		/* kernel context */
1078 		loop = 0;
1079 		while (1) {
1080 			count = get_buffers_allocated(sc);
1081 			if (count == 0)
1082 				break;
1083 			if (loop > 100) {
1084 				dd_dev_err(dd,
1085 					   "%s: context %u(%u) timeout waiting for PIO buffers to zero, remaining %d\n",
1086 					   __func__, sc->sw_index,
1087 					   sc->hw_context, count);
1088 			}
1089 			loop++;
1090 			udelay(1);
1091 		}
1092 	}
1093 
1094 	/*
1095 	 * Step 3: Wait for all packets to egress.
1096 	 * This is done while disabling the send context
1097 	 *
1098 	 * Step 4: Disable the context
1099 	 *
1100 	 * This is a superset of the halt.  After the disable, the
1101 	 * errors can be cleared.
1102 	 */
1103 	sc_disable(sc);
1104 
1105 	/*
1106 	 * Step 5: Enable the context
1107 	 *
1108 	 * This enable will clear the halted flag and per-send context
1109 	 * error flags.
1110 	 */
1111 	return sc_enable(sc);
1112 }
1113 
1114 /*
1115  * PIO freeze processing.  To be called after the TXE block is fully frozen.
1116  * Go through all frozen send contexts and disable them.  The contexts are
1117  * already stopped by the freeze.
1118  */
pio_freeze(struct hfi1_devdata * dd)1119 void pio_freeze(struct hfi1_devdata *dd)
1120 {
1121 	struct send_context *sc;
1122 	int i;
1123 
1124 	for (i = 0; i < dd->num_send_contexts; i++) {
1125 		sc = dd->send_contexts[i].sc;
1126 		/*
1127 		 * Don't disable unallocated, unfrozen, or user send contexts.
1128 		 * User send contexts will be disabled when the process
1129 		 * calls into the driver to reset its context.
1130 		 */
1131 		if (!sc || !(sc->flags & SCF_FROZEN) || sc->type == SC_USER)
1132 			continue;
1133 
1134 		/* only need to disable, the context is already stopped */
1135 		sc_disable(sc);
1136 	}
1137 }
1138 
1139 /*
1140  * Unfreeze PIO for kernel send contexts.  The precondition for calling this
1141  * is that all PIO send contexts have been disabled and the SPC freeze has
1142  * been cleared.  Now perform the last step and re-enable each kernel context.
1143  * User (PSM) processing will occur when PSM calls into the kernel to
1144  * acknowledge the freeze.
1145  */
pio_kernel_unfreeze(struct hfi1_devdata * dd)1146 void pio_kernel_unfreeze(struct hfi1_devdata *dd)
1147 {
1148 	struct send_context *sc;
1149 	int i;
1150 
1151 	for (i = 0; i < dd->num_send_contexts; i++) {
1152 		sc = dd->send_contexts[i].sc;
1153 		if (!sc || !(sc->flags & SCF_FROZEN) || sc->type == SC_USER)
1154 			continue;
1155 		if (sc->flags & SCF_LINK_DOWN)
1156 			continue;
1157 
1158 		sc_enable(sc);	/* will clear the sc frozen flag */
1159 	}
1160 }
1161 
1162 /**
1163  * pio_kernel_linkup() - Re-enable send contexts after linkup event
1164  * @dd: valid devive data
1165  *
1166  * When the link goes down, the freeze path is taken.  However, a link down
1167  * event is different from a freeze because if the send context is re-enabled
1168  * whowever is sending data will start sending data again, which will hang
1169  * any QP that is sending data.
1170  *
1171  * The freeze path now looks at the type of event that occurs and takes this
1172  * path for link down event.
1173  */
pio_kernel_linkup(struct hfi1_devdata * dd)1174 void pio_kernel_linkup(struct hfi1_devdata *dd)
1175 {
1176 	struct send_context *sc;
1177 	int i;
1178 
1179 	for (i = 0; i < dd->num_send_contexts; i++) {
1180 		sc = dd->send_contexts[i].sc;
1181 		if (!sc || !(sc->flags & SCF_LINK_DOWN) || sc->type == SC_USER)
1182 			continue;
1183 
1184 		sc_enable(sc);	/* will clear the sc link down flag */
1185 	}
1186 }
1187 
1188 /*
1189  * Wait for the SendPioInitCtxt.PioInitInProgress bit to clear.
1190  * Returns:
1191  *	-ETIMEDOUT - if we wait too long
1192  *	-EIO	   - if there was an error
1193  */
pio_init_wait_progress(struct hfi1_devdata * dd)1194 static int pio_init_wait_progress(struct hfi1_devdata *dd)
1195 {
1196 	u64 reg;
1197 	int max, count = 0;
1198 
1199 	/* max is the longest possible HW init time / delay */
1200 	max = (dd->icode == ICODE_FPGA_EMULATION) ? 120 : 5;
1201 	while (1) {
1202 		reg = read_csr(dd, SEND_PIO_INIT_CTXT);
1203 		if (!(reg & SEND_PIO_INIT_CTXT_PIO_INIT_IN_PROGRESS_SMASK))
1204 			break;
1205 		if (count >= max)
1206 			return -ETIMEDOUT;
1207 		udelay(5);
1208 		count++;
1209 	}
1210 
1211 	return reg & SEND_PIO_INIT_CTXT_PIO_INIT_ERR_SMASK ? -EIO : 0;
1212 }
1213 
1214 /*
1215  * Reset all of the send contexts to their power-on state.  Used
1216  * only during manual init - no lock against sc_enable needed.
1217  */
pio_reset_all(struct hfi1_devdata * dd)1218 void pio_reset_all(struct hfi1_devdata *dd)
1219 {
1220 	int ret;
1221 
1222 	/* make sure the init engine is not busy */
1223 	ret = pio_init_wait_progress(dd);
1224 	/* ignore any timeout */
1225 	if (ret == -EIO) {
1226 		/* clear the error */
1227 		write_csr(dd, SEND_PIO_ERR_CLEAR,
1228 			  SEND_PIO_ERR_CLEAR_PIO_INIT_SM_IN_ERR_SMASK);
1229 	}
1230 
1231 	/* reset init all */
1232 	write_csr(dd, SEND_PIO_INIT_CTXT,
1233 		  SEND_PIO_INIT_CTXT_PIO_ALL_CTXT_INIT_SMASK);
1234 	udelay(2);
1235 	ret = pio_init_wait_progress(dd);
1236 	if (ret < 0) {
1237 		dd_dev_err(dd,
1238 			   "PIO send context init %s while initializing all PIO blocks\n",
1239 			   ret == -ETIMEDOUT ? "is stuck" : "had an error");
1240 	}
1241 }
1242 
1243 /* enable the context */
sc_enable(struct send_context * sc)1244 int sc_enable(struct send_context *sc)
1245 {
1246 	u64 sc_ctrl, reg, pio;
1247 	struct hfi1_devdata *dd;
1248 	unsigned long flags;
1249 	int ret = 0;
1250 
1251 	if (!sc)
1252 		return -EINVAL;
1253 	dd = sc->dd;
1254 
1255 	/*
1256 	 * Obtain the allocator lock to guard against any allocation
1257 	 * attempts (which should not happen prior to context being
1258 	 * enabled). On the release/disable side we don't need to
1259 	 * worry about locking since the releaser will not do anything
1260 	 * if the context accounting values have not changed.
1261 	 */
1262 	spin_lock_irqsave(&sc->alloc_lock, flags);
1263 	sc_ctrl = read_kctxt_csr(dd, sc->hw_context, SC(CTRL));
1264 	if ((sc_ctrl & SC(CTRL_CTXT_ENABLE_SMASK)))
1265 		goto unlock; /* already enabled */
1266 
1267 	/* IMPORTANT: only clear free and fill if transitioning 0 -> 1 */
1268 
1269 	*sc->hw_free = 0;
1270 	sc->free = 0;
1271 	sc->alloc_free = 0;
1272 	sc->fill = 0;
1273 	sc->fill_wrap = 0;
1274 	sc->sr_head = 0;
1275 	sc->sr_tail = 0;
1276 	sc->flags = 0;
1277 	/* the alloc lock insures no fast path allocation */
1278 	reset_buffers_allocated(sc);
1279 
1280 	/*
1281 	 * Clear all per-context errors.  Some of these will be set when
1282 	 * we are re-enabling after a context halt.  Now that the context
1283 	 * is disabled, the halt will not clear until after the PIO init
1284 	 * engine runs below.
1285 	 */
1286 	reg = read_kctxt_csr(dd, sc->hw_context, SC(ERR_STATUS));
1287 	if (reg)
1288 		write_kctxt_csr(dd, sc->hw_context, SC(ERR_CLEAR), reg);
1289 
1290 	/*
1291 	 * The HW PIO initialization engine can handle only one init
1292 	 * request at a time. Serialize access to each device's engine.
1293 	 */
1294 	spin_lock(&dd->sc_init_lock);
1295 	/*
1296 	 * Since access to this code block is serialized and
1297 	 * each access waits for the initialization to complete
1298 	 * before releasing the lock, the PIO initialization engine
1299 	 * should not be in use, so we don't have to wait for the
1300 	 * InProgress bit to go down.
1301 	 */
1302 	pio = ((sc->hw_context & SEND_PIO_INIT_CTXT_PIO_CTXT_NUM_MASK) <<
1303 	       SEND_PIO_INIT_CTXT_PIO_CTXT_NUM_SHIFT) |
1304 		SEND_PIO_INIT_CTXT_PIO_SINGLE_CTXT_INIT_SMASK;
1305 	write_csr(dd, SEND_PIO_INIT_CTXT, pio);
1306 	/*
1307 	 * Wait until the engine is done.  Give the chip the required time
1308 	 * so, hopefully, we read the register just once.
1309 	 */
1310 	udelay(2);
1311 	ret = pio_init_wait_progress(dd);
1312 	spin_unlock(&dd->sc_init_lock);
1313 	if (ret) {
1314 		dd_dev_err(dd,
1315 			   "sctxt%u(%u): Context not enabled due to init failure %d\n",
1316 			   sc->sw_index, sc->hw_context, ret);
1317 		goto unlock;
1318 	}
1319 
1320 	/*
1321 	 * All is well. Enable the context.
1322 	 */
1323 	sc_ctrl |= SC(CTRL_CTXT_ENABLE_SMASK);
1324 	write_kctxt_csr(dd, sc->hw_context, SC(CTRL), sc_ctrl);
1325 	/*
1326 	 * Read SendCtxtCtrl to force the write out and prevent a timing
1327 	 * hazard where a PIO write may reach the context before the enable.
1328 	 */
1329 	read_kctxt_csr(dd, sc->hw_context, SC(CTRL));
1330 	sc->flags |= SCF_ENABLED;
1331 
1332 unlock:
1333 	spin_unlock_irqrestore(&sc->alloc_lock, flags);
1334 
1335 	return ret;
1336 }
1337 
1338 /* force a credit return on the context */
sc_return_credits(struct send_context * sc)1339 void sc_return_credits(struct send_context *sc)
1340 {
1341 	if (!sc)
1342 		return;
1343 
1344 	/* a 0->1 transition schedules a credit return */
1345 	write_kctxt_csr(sc->dd, sc->hw_context, SC(CREDIT_FORCE),
1346 			SC(CREDIT_FORCE_FORCE_RETURN_SMASK));
1347 	/*
1348 	 * Ensure that the write is flushed and the credit return is
1349 	 * scheduled. We care more about the 0 -> 1 transition.
1350 	 */
1351 	read_kctxt_csr(sc->dd, sc->hw_context, SC(CREDIT_FORCE));
1352 	/* set back to 0 for next time */
1353 	write_kctxt_csr(sc->dd, sc->hw_context, SC(CREDIT_FORCE), 0);
1354 }
1355 
1356 /* allow all in-flight packets to drain on the context */
sc_flush(struct send_context * sc)1357 void sc_flush(struct send_context *sc)
1358 {
1359 	if (!sc)
1360 		return;
1361 
1362 	sc_wait_for_packet_egress(sc, 1);
1363 }
1364 
1365 /* drop all packets on the context, no waiting until they are sent */
sc_drop(struct send_context * sc)1366 void sc_drop(struct send_context *sc)
1367 {
1368 	if (!sc)
1369 		return;
1370 
1371 	dd_dev_info(sc->dd, "%s: context %u(%u) - not implemented\n",
1372 		    __func__, sc->sw_index, sc->hw_context);
1373 }
1374 
1375 /*
1376  * Start the software reaction to a context halt or SPC freeze:
1377  *	- mark the context as halted or frozen
1378  *	- stop buffer allocations
1379  *
1380  * Called from the error interrupt.  Other work is deferred until
1381  * out of the interrupt.
1382  */
sc_stop(struct send_context * sc,int flag)1383 void sc_stop(struct send_context *sc, int flag)
1384 {
1385 	unsigned long flags;
1386 
1387 	/* stop buffer allocations */
1388 	spin_lock_irqsave(&sc->alloc_lock, flags);
1389 	/* mark the context */
1390 	sc->flags |= flag;
1391 	sc->flags &= ~SCF_ENABLED;
1392 	spin_unlock_irqrestore(&sc->alloc_lock, flags);
1393 	wake_up(&sc->halt_wait);
1394 }
1395 
1396 #define BLOCK_DWORDS (PIO_BLOCK_SIZE / sizeof(u32))
1397 #define dwords_to_blocks(x) DIV_ROUND_UP(x, BLOCK_DWORDS)
1398 
1399 /*
1400  * The send context buffer "allocator".
1401  *
1402  * @sc: the PIO send context we are allocating from
1403  * @len: length of whole packet - including PBC - in dwords
1404  * @cb: optional callback to call when the buffer is finished sending
1405  * @arg: argument for cb
1406  *
1407  * Return a pointer to a PIO buffer, NULL if not enough room, -ECOMM
1408  * when link is down.
1409  */
sc_buffer_alloc(struct send_context * sc,u32 dw_len,pio_release_cb cb,void * arg)1410 struct pio_buf *sc_buffer_alloc(struct send_context *sc, u32 dw_len,
1411 				pio_release_cb cb, void *arg)
1412 {
1413 	struct pio_buf *pbuf = NULL;
1414 	unsigned long flags;
1415 	unsigned long avail;
1416 	unsigned long blocks = dwords_to_blocks(dw_len);
1417 	u32 fill_wrap;
1418 	int trycount = 0;
1419 	u32 head, next;
1420 
1421 	spin_lock_irqsave(&sc->alloc_lock, flags);
1422 	if (!(sc->flags & SCF_ENABLED)) {
1423 		spin_unlock_irqrestore(&sc->alloc_lock, flags);
1424 		return ERR_PTR(-ECOMM);
1425 	}
1426 
1427 retry:
1428 	avail = (unsigned long)sc->credits - (sc->fill - sc->alloc_free);
1429 	if (blocks > avail) {
1430 		/* not enough room */
1431 		if (unlikely(trycount))	{ /* already tried to get more room */
1432 			spin_unlock_irqrestore(&sc->alloc_lock, flags);
1433 			goto done;
1434 		}
1435 		/* copy from receiver cache line and recalculate */
1436 		sc->alloc_free = READ_ONCE(sc->free);
1437 		avail =
1438 			(unsigned long)sc->credits -
1439 			(sc->fill - sc->alloc_free);
1440 		if (blocks > avail) {
1441 			/* still no room, actively update */
1442 			sc_release_update(sc);
1443 			sc->alloc_free = READ_ONCE(sc->free);
1444 			trycount++;
1445 			goto retry;
1446 		}
1447 	}
1448 
1449 	/* there is enough room */
1450 
1451 	preempt_disable();
1452 	this_cpu_inc(*sc->buffers_allocated);
1453 
1454 	/* read this once */
1455 	head = sc->sr_head;
1456 
1457 	/* "allocate" the buffer */
1458 	sc->fill += blocks;
1459 	fill_wrap = sc->fill_wrap;
1460 	sc->fill_wrap += blocks;
1461 	if (sc->fill_wrap >= sc->credits)
1462 		sc->fill_wrap = sc->fill_wrap - sc->credits;
1463 
1464 	/*
1465 	 * Fill the parts that the releaser looks at before moving the head.
1466 	 * The only necessary piece is the sent_at field.  The credits
1467 	 * we have just allocated cannot have been returned yet, so the
1468 	 * cb and arg will not be looked at for a "while".  Put them
1469 	 * on this side of the memory barrier anyway.
1470 	 */
1471 	pbuf = &sc->sr[head].pbuf;
1472 	pbuf->sent_at = sc->fill;
1473 	pbuf->cb = cb;
1474 	pbuf->arg = arg;
1475 	pbuf->sc = sc;	/* could be filled in at sc->sr init time */
1476 	/* make sure this is in memory before updating the head */
1477 
1478 	/* calculate next head index, do not store */
1479 	next = head + 1;
1480 	if (next >= sc->sr_size)
1481 		next = 0;
1482 	/*
1483 	 * update the head - must be last! - the releaser can look at fields
1484 	 * in pbuf once we move the head
1485 	 */
1486 	smp_wmb();
1487 	sc->sr_head = next;
1488 	spin_unlock_irqrestore(&sc->alloc_lock, flags);
1489 
1490 	/* finish filling in the buffer outside the lock */
1491 	pbuf->start = sc->base_addr + fill_wrap * PIO_BLOCK_SIZE;
1492 	pbuf->end = sc->base_addr + sc->size;
1493 	pbuf->qw_written = 0;
1494 	pbuf->carry_bytes = 0;
1495 	pbuf->carry.val64 = 0;
1496 done:
1497 	return pbuf;
1498 }
1499 
1500 /*
1501  * There are at least two entities that can turn on credit return
1502  * interrupts and they can overlap.  Avoid problems by implementing
1503  * a count scheme that is enforced by a lock.  The lock is needed because
1504  * the count and CSR write must be paired.
1505  */
1506 
1507 /*
1508  * Start credit return interrupts.  This is managed by a count.  If already
1509  * on, just increment the count.
1510  */
sc_add_credit_return_intr(struct send_context * sc)1511 void sc_add_credit_return_intr(struct send_context *sc)
1512 {
1513 	unsigned long flags;
1514 
1515 	/* lock must surround both the count change and the CSR update */
1516 	spin_lock_irqsave(&sc->credit_ctrl_lock, flags);
1517 	if (sc->credit_intr_count == 0) {
1518 		sc->credit_ctrl |= SC(CREDIT_CTRL_CREDIT_INTR_SMASK);
1519 		write_kctxt_csr(sc->dd, sc->hw_context,
1520 				SC(CREDIT_CTRL), sc->credit_ctrl);
1521 	}
1522 	sc->credit_intr_count++;
1523 	spin_unlock_irqrestore(&sc->credit_ctrl_lock, flags);
1524 }
1525 
1526 /*
1527  * Stop credit return interrupts.  This is managed by a count.  Decrement the
1528  * count, if the last user, then turn the credit interrupts off.
1529  */
sc_del_credit_return_intr(struct send_context * sc)1530 void sc_del_credit_return_intr(struct send_context *sc)
1531 {
1532 	unsigned long flags;
1533 
1534 	WARN_ON(sc->credit_intr_count == 0);
1535 
1536 	/* lock must surround both the count change and the CSR update */
1537 	spin_lock_irqsave(&sc->credit_ctrl_lock, flags);
1538 	sc->credit_intr_count--;
1539 	if (sc->credit_intr_count == 0) {
1540 		sc->credit_ctrl &= ~SC(CREDIT_CTRL_CREDIT_INTR_SMASK);
1541 		write_kctxt_csr(sc->dd, sc->hw_context,
1542 				SC(CREDIT_CTRL), sc->credit_ctrl);
1543 	}
1544 	spin_unlock_irqrestore(&sc->credit_ctrl_lock, flags);
1545 }
1546 
1547 /*
1548  * The caller must be careful when calling this.  All needint calls
1549  * must be paired with !needint.
1550  */
hfi1_sc_wantpiobuf_intr(struct send_context * sc,u32 needint)1551 void hfi1_sc_wantpiobuf_intr(struct send_context *sc, u32 needint)
1552 {
1553 	if (needint)
1554 		sc_add_credit_return_intr(sc);
1555 	else
1556 		sc_del_credit_return_intr(sc);
1557 	trace_hfi1_wantpiointr(sc, needint, sc->credit_ctrl);
1558 	if (needint)
1559 		sc_return_credits(sc);
1560 }
1561 
1562 /**
1563  * sc_piobufavail - callback when a PIO buffer is available
1564  * @sc: the send context
1565  *
1566  * This is called from the interrupt handler when a PIO buffer is
1567  * available after hfi1_verbs_send() returned an error that no buffers were
1568  * available. Disable the interrupt if there are no more QPs waiting.
1569  */
sc_piobufavail(struct send_context * sc)1570 static void sc_piobufavail(struct send_context *sc)
1571 {
1572 	struct hfi1_devdata *dd = sc->dd;
1573 	struct list_head *list;
1574 	struct rvt_qp *qps[PIO_WAIT_BATCH_SIZE];
1575 	struct rvt_qp *qp;
1576 	struct hfi1_qp_priv *priv;
1577 	unsigned long flags;
1578 	uint i, n = 0, top_idx = 0;
1579 
1580 	if (dd->send_contexts[sc->sw_index].type != SC_KERNEL &&
1581 	    dd->send_contexts[sc->sw_index].type != SC_VL15)
1582 		return;
1583 	list = &sc->piowait;
1584 	/*
1585 	 * Note: checking that the piowait list is empty and clearing
1586 	 * the buffer available interrupt needs to be atomic or we
1587 	 * could end up with QPs on the wait list with the interrupt
1588 	 * disabled.
1589 	 */
1590 	write_seqlock_irqsave(&sc->waitlock, flags);
1591 	while (!list_empty(list)) {
1592 		struct iowait *wait;
1593 
1594 		if (n == ARRAY_SIZE(qps))
1595 			break;
1596 		wait = list_first_entry(list, struct iowait, list);
1597 		iowait_get_priority(wait);
1598 		qp = iowait_to_qp(wait);
1599 		priv = qp->priv;
1600 		list_del_init(&priv->s_iowait.list);
1601 		priv->s_iowait.lock = NULL;
1602 		if (n) {
1603 			priv = qps[top_idx]->priv;
1604 			top_idx = iowait_priority_update_top(wait,
1605 							     &priv->s_iowait,
1606 							     n, top_idx);
1607 		}
1608 
1609 		/* refcount held until actual wake up */
1610 		qps[n++] = qp;
1611 	}
1612 	/*
1613 	 * If there had been waiters and there are more
1614 	 * insure that we redo the force to avoid a potential hang.
1615 	 */
1616 	if (n) {
1617 		hfi1_sc_wantpiobuf_intr(sc, 0);
1618 		if (!list_empty(list))
1619 			hfi1_sc_wantpiobuf_intr(sc, 1);
1620 	}
1621 	write_sequnlock_irqrestore(&sc->waitlock, flags);
1622 
1623 	/* Wake up the top-priority one first */
1624 	if (n)
1625 		hfi1_qp_wakeup(qps[top_idx],
1626 			       RVT_S_WAIT_PIO | HFI1_S_WAIT_PIO_DRAIN);
1627 	for (i = 0; i < n; i++)
1628 		if (i != top_idx)
1629 			hfi1_qp_wakeup(qps[i],
1630 				       RVT_S_WAIT_PIO | HFI1_S_WAIT_PIO_DRAIN);
1631 }
1632 
1633 /* translate a send credit update to a bit code of reasons */
fill_code(u64 hw_free)1634 static inline int fill_code(u64 hw_free)
1635 {
1636 	int code = 0;
1637 
1638 	if (hw_free & CR_STATUS_SMASK)
1639 		code |= PRC_STATUS_ERR;
1640 	if (hw_free & CR_CREDIT_RETURN_DUE_TO_PBC_SMASK)
1641 		code |= PRC_PBC;
1642 	if (hw_free & CR_CREDIT_RETURN_DUE_TO_THRESHOLD_SMASK)
1643 		code |= PRC_THRESHOLD;
1644 	if (hw_free & CR_CREDIT_RETURN_DUE_TO_ERR_SMASK)
1645 		code |= PRC_FILL_ERR;
1646 	if (hw_free & CR_CREDIT_RETURN_DUE_TO_FORCE_SMASK)
1647 		code |= PRC_SC_DISABLE;
1648 	return code;
1649 }
1650 
1651 /* use the jiffies compare to get the wrap right */
1652 #define sent_before(a, b) time_before(a, b)	/* a < b */
1653 
1654 /*
1655  * The send context buffer "releaser".
1656  */
sc_release_update(struct send_context * sc)1657 void sc_release_update(struct send_context *sc)
1658 {
1659 	struct pio_buf *pbuf;
1660 	u64 hw_free;
1661 	u32 head, tail;
1662 	unsigned long old_free;
1663 	unsigned long free;
1664 	unsigned long extra;
1665 	unsigned long flags;
1666 	int code;
1667 
1668 	if (!sc)
1669 		return;
1670 
1671 	spin_lock_irqsave(&sc->release_lock, flags);
1672 	/* update free */
1673 	hw_free = le64_to_cpu(*sc->hw_free);		/* volatile read */
1674 	old_free = sc->free;
1675 	extra = (((hw_free & CR_COUNTER_SMASK) >> CR_COUNTER_SHIFT)
1676 			- (old_free & CR_COUNTER_MASK))
1677 				& CR_COUNTER_MASK;
1678 	free = old_free + extra;
1679 	trace_hfi1_piofree(sc, extra);
1680 
1681 	/* call sent buffer callbacks */
1682 	code = -1;				/* code not yet set */
1683 	head = READ_ONCE(sc->sr_head);	/* snapshot the head */
1684 	tail = sc->sr_tail;
1685 	while (head != tail) {
1686 		pbuf = &sc->sr[tail].pbuf;
1687 
1688 		if (sent_before(free, pbuf->sent_at)) {
1689 			/* not sent yet */
1690 			break;
1691 		}
1692 		if (pbuf->cb) {
1693 			if (code < 0) /* fill in code on first user */
1694 				code = fill_code(hw_free);
1695 			(*pbuf->cb)(pbuf->arg, code);
1696 		}
1697 
1698 		tail++;
1699 		if (tail >= sc->sr_size)
1700 			tail = 0;
1701 	}
1702 	sc->sr_tail = tail;
1703 	/* make sure tail is updated before free */
1704 	smp_wmb();
1705 	sc->free = free;
1706 	spin_unlock_irqrestore(&sc->release_lock, flags);
1707 	sc_piobufavail(sc);
1708 }
1709 
1710 /*
1711  * Send context group releaser.  Argument is the send context that caused
1712  * the interrupt.  Called from the send context interrupt handler.
1713  *
1714  * Call release on all contexts in the group.
1715  *
1716  * This routine takes the sc_lock without an irqsave because it is only
1717  * called from an interrupt handler.  Adjust if that changes.
1718  */
sc_group_release_update(struct hfi1_devdata * dd,u32 hw_context)1719 void sc_group_release_update(struct hfi1_devdata *dd, u32 hw_context)
1720 {
1721 	struct send_context *sc;
1722 	u32 sw_index;
1723 	u32 gc, gc_end;
1724 
1725 	spin_lock(&dd->sc_lock);
1726 	sw_index = dd->hw_to_sw[hw_context];
1727 	if (unlikely(sw_index >= dd->num_send_contexts)) {
1728 		dd_dev_err(dd, "%s: invalid hw (%u) to sw (%u) mapping\n",
1729 			   __func__, hw_context, sw_index);
1730 		goto done;
1731 	}
1732 	sc = dd->send_contexts[sw_index].sc;
1733 	if (unlikely(!sc))
1734 		goto done;
1735 
1736 	gc = group_context(hw_context, sc->group);
1737 	gc_end = gc + group_size(sc->group);
1738 	for (; gc < gc_end; gc++) {
1739 		sw_index = dd->hw_to_sw[gc];
1740 		if (unlikely(sw_index >= dd->num_send_contexts)) {
1741 			dd_dev_err(dd,
1742 				   "%s: invalid hw (%u) to sw (%u) mapping\n",
1743 				   __func__, hw_context, sw_index);
1744 			continue;
1745 		}
1746 		sc_release_update(dd->send_contexts[sw_index].sc);
1747 	}
1748 done:
1749 	spin_unlock(&dd->sc_lock);
1750 }
1751 
1752 /*
1753  * pio_select_send_context_vl() - select send context
1754  * @dd: devdata
1755  * @selector: a spreading factor
1756  * @vl: this vl
1757  *
1758  * This function returns a send context based on the selector and a vl.
1759  * The mapping fields are protected by RCU
1760  */
pio_select_send_context_vl(struct hfi1_devdata * dd,u32 selector,u8 vl)1761 struct send_context *pio_select_send_context_vl(struct hfi1_devdata *dd,
1762 						u32 selector, u8 vl)
1763 {
1764 	struct pio_vl_map *m;
1765 	struct pio_map_elem *e;
1766 	struct send_context *rval;
1767 
1768 	/*
1769 	 * NOTE This should only happen if SC->VL changed after the initial
1770 	 * checks on the QP/AH
1771 	 * Default will return VL0's send context below
1772 	 */
1773 	if (unlikely(vl >= num_vls)) {
1774 		rval = NULL;
1775 		goto done;
1776 	}
1777 
1778 	rcu_read_lock();
1779 	m = rcu_dereference(dd->pio_map);
1780 	if (unlikely(!m)) {
1781 		rcu_read_unlock();
1782 		return dd->vld[0].sc;
1783 	}
1784 	e = m->map[vl & m->mask];
1785 	rval = e->ksc[selector & e->mask];
1786 	rcu_read_unlock();
1787 
1788 done:
1789 	rval = !rval ? dd->vld[0].sc : rval;
1790 	return rval;
1791 }
1792 
1793 /*
1794  * pio_select_send_context_sc() - select send context
1795  * @dd: devdata
1796  * @selector: a spreading factor
1797  * @sc5: the 5 bit sc
1798  *
1799  * This function returns an send context based on the selector and an sc
1800  */
pio_select_send_context_sc(struct hfi1_devdata * dd,u32 selector,u8 sc5)1801 struct send_context *pio_select_send_context_sc(struct hfi1_devdata *dd,
1802 						u32 selector, u8 sc5)
1803 {
1804 	u8 vl = sc_to_vlt(dd, sc5);
1805 
1806 	return pio_select_send_context_vl(dd, selector, vl);
1807 }
1808 
1809 /*
1810  * Free the indicated map struct
1811  */
pio_map_free(struct pio_vl_map * m)1812 static void pio_map_free(struct pio_vl_map *m)
1813 {
1814 	int i;
1815 
1816 	for (i = 0; m && i < m->actual_vls; i++)
1817 		kfree(m->map[i]);
1818 	kfree(m);
1819 }
1820 
1821 /*
1822  * Handle RCU callback
1823  */
pio_map_rcu_callback(struct rcu_head * list)1824 static void pio_map_rcu_callback(struct rcu_head *list)
1825 {
1826 	struct pio_vl_map *m = container_of(list, struct pio_vl_map, list);
1827 
1828 	pio_map_free(m);
1829 }
1830 
1831 /*
1832  * Set credit return threshold for the kernel send context
1833  */
set_threshold(struct hfi1_devdata * dd,int scontext,int i)1834 static void set_threshold(struct hfi1_devdata *dd, int scontext, int i)
1835 {
1836 	u32 thres;
1837 
1838 	thres = min(sc_percent_to_threshold(dd->kernel_send_context[scontext],
1839 					    50),
1840 		    sc_mtu_to_threshold(dd->kernel_send_context[scontext],
1841 					dd->vld[i].mtu,
1842 					dd->rcd[0]->rcvhdrqentsize));
1843 	sc_set_cr_threshold(dd->kernel_send_context[scontext], thres);
1844 }
1845 
1846 /*
1847  * pio_map_init - called when #vls change
1848  * @dd: hfi1_devdata
1849  * @port: port number
1850  * @num_vls: number of vls
1851  * @vl_scontexts: per vl send context mapping (optional)
1852  *
1853  * This routine changes the mapping based on the number of vls.
1854  *
1855  * vl_scontexts is used to specify a non-uniform vl/send context
1856  * loading. NULL implies auto computing the loading and giving each
1857  * VL an uniform distribution of send contexts per VL.
1858  *
1859  * The auto algorithm computers the sc_per_vl and the number of extra
1860  * send contexts. Any extra send contexts are added from the last VL
1861  * on down
1862  *
1863  * rcu locking is used here to control access to the mapping fields.
1864  *
1865  * If either the num_vls or num_send_contexts are non-power of 2, the
1866  * array sizes in the struct pio_vl_map and the struct pio_map_elem are
1867  * rounded up to the next highest power of 2 and the first entry is
1868  * reused in a round robin fashion.
1869  *
1870  * If an error occurs the map change is not done and the mapping is not
1871  * chaged.
1872  *
1873  */
pio_map_init(struct hfi1_devdata * dd,u8 port,u8 num_vls,u8 * vl_scontexts)1874 int pio_map_init(struct hfi1_devdata *dd, u8 port, u8 num_vls, u8 *vl_scontexts)
1875 {
1876 	int i, j;
1877 	int extra, sc_per_vl;
1878 	int scontext = 1;
1879 	int num_kernel_send_contexts = 0;
1880 	u8 lvl_scontexts[OPA_MAX_VLS];
1881 	struct pio_vl_map *oldmap, *newmap;
1882 
1883 	if (!vl_scontexts) {
1884 		for (i = 0; i < dd->num_send_contexts; i++)
1885 			if (dd->send_contexts[i].type == SC_KERNEL)
1886 				num_kernel_send_contexts++;
1887 		/* truncate divide */
1888 		sc_per_vl = num_kernel_send_contexts / num_vls;
1889 		/* extras */
1890 		extra = num_kernel_send_contexts % num_vls;
1891 		vl_scontexts = lvl_scontexts;
1892 		/* add extras from last vl down */
1893 		for (i = num_vls - 1; i >= 0; i--, extra--)
1894 			vl_scontexts[i] = sc_per_vl + (extra > 0 ? 1 : 0);
1895 	}
1896 	/* build new map */
1897 	newmap = kzalloc(sizeof(*newmap) +
1898 			 roundup_pow_of_two(num_vls) *
1899 			 sizeof(struct pio_map_elem *),
1900 			 GFP_KERNEL);
1901 	if (!newmap)
1902 		goto bail;
1903 	newmap->actual_vls = num_vls;
1904 	newmap->vls = roundup_pow_of_two(num_vls);
1905 	newmap->mask = (1 << ilog2(newmap->vls)) - 1;
1906 	for (i = 0; i < newmap->vls; i++) {
1907 		/* save for wrap around */
1908 		int first_scontext = scontext;
1909 
1910 		if (i < newmap->actual_vls) {
1911 			int sz = roundup_pow_of_two(vl_scontexts[i]);
1912 
1913 			/* only allocate once */
1914 			newmap->map[i] = kzalloc(sizeof(*newmap->map[i]) +
1915 						 sz * sizeof(struct
1916 							     send_context *),
1917 						 GFP_KERNEL);
1918 			if (!newmap->map[i])
1919 				goto bail;
1920 			newmap->map[i]->mask = (1 << ilog2(sz)) - 1;
1921 			/*
1922 			 * assign send contexts and
1923 			 * adjust credit return threshold
1924 			 */
1925 			for (j = 0; j < sz; j++) {
1926 				if (dd->kernel_send_context[scontext]) {
1927 					newmap->map[i]->ksc[j] =
1928 					dd->kernel_send_context[scontext];
1929 					set_threshold(dd, scontext, i);
1930 				}
1931 				if (++scontext >= first_scontext +
1932 						  vl_scontexts[i])
1933 					/* wrap back to first send context */
1934 					scontext = first_scontext;
1935 			}
1936 		} else {
1937 			/* just re-use entry without allocating */
1938 			newmap->map[i] = newmap->map[i % num_vls];
1939 		}
1940 		scontext = first_scontext + vl_scontexts[i];
1941 	}
1942 	/* newmap in hand, save old map */
1943 	spin_lock_irq(&dd->pio_map_lock);
1944 	oldmap = rcu_dereference_protected(dd->pio_map,
1945 					   lockdep_is_held(&dd->pio_map_lock));
1946 
1947 	/* publish newmap */
1948 	rcu_assign_pointer(dd->pio_map, newmap);
1949 
1950 	spin_unlock_irq(&dd->pio_map_lock);
1951 	/* success, free any old map after grace period */
1952 	if (oldmap)
1953 		call_rcu(&oldmap->list, pio_map_rcu_callback);
1954 	return 0;
1955 bail:
1956 	/* free any partial allocation */
1957 	pio_map_free(newmap);
1958 	return -ENOMEM;
1959 }
1960 
free_pio_map(struct hfi1_devdata * dd)1961 void free_pio_map(struct hfi1_devdata *dd)
1962 {
1963 	/* Free PIO map if allocated */
1964 	if (rcu_access_pointer(dd->pio_map)) {
1965 		spin_lock_irq(&dd->pio_map_lock);
1966 		pio_map_free(rcu_access_pointer(dd->pio_map));
1967 		RCU_INIT_POINTER(dd->pio_map, NULL);
1968 		spin_unlock_irq(&dd->pio_map_lock);
1969 		synchronize_rcu();
1970 	}
1971 	kfree(dd->kernel_send_context);
1972 	dd->kernel_send_context = NULL;
1973 }
1974 
init_pervl_scs(struct hfi1_devdata * dd)1975 int init_pervl_scs(struct hfi1_devdata *dd)
1976 {
1977 	int i;
1978 	u64 mask, all_vl_mask = (u64)0x80ff; /* VLs 0-7, 15 */
1979 	u64 data_vls_mask = (u64)0x00ff; /* VLs 0-7 */
1980 	u32 ctxt;
1981 	struct hfi1_pportdata *ppd = dd->pport;
1982 
1983 	dd->vld[15].sc = sc_alloc(dd, SC_VL15,
1984 				  dd->rcd[0]->rcvhdrqentsize, dd->node);
1985 	if (!dd->vld[15].sc)
1986 		return -ENOMEM;
1987 
1988 	hfi1_init_ctxt(dd->vld[15].sc);
1989 	dd->vld[15].mtu = enum_to_mtu(OPA_MTU_2048);
1990 
1991 	dd->kernel_send_context = kcalloc_node(dd->num_send_contexts,
1992 					       sizeof(struct send_context *),
1993 					       GFP_KERNEL, dd->node);
1994 	if (!dd->kernel_send_context)
1995 		goto freesc15;
1996 
1997 	dd->kernel_send_context[0] = dd->vld[15].sc;
1998 
1999 	for (i = 0; i < num_vls; i++) {
2000 		/*
2001 		 * Since this function does not deal with a specific
2002 		 * receive context but we need the RcvHdrQ entry size,
2003 		 * use the size from rcd[0]. It is guaranteed to be
2004 		 * valid at this point and will remain the same for all
2005 		 * receive contexts.
2006 		 */
2007 		dd->vld[i].sc = sc_alloc(dd, SC_KERNEL,
2008 					 dd->rcd[0]->rcvhdrqentsize, dd->node);
2009 		if (!dd->vld[i].sc)
2010 			goto nomem;
2011 		dd->kernel_send_context[i + 1] = dd->vld[i].sc;
2012 		hfi1_init_ctxt(dd->vld[i].sc);
2013 		/* non VL15 start with the max MTU */
2014 		dd->vld[i].mtu = hfi1_max_mtu;
2015 	}
2016 	for (i = num_vls; i < INIT_SC_PER_VL * num_vls; i++) {
2017 		dd->kernel_send_context[i + 1] =
2018 		sc_alloc(dd, SC_KERNEL, dd->rcd[0]->rcvhdrqentsize, dd->node);
2019 		if (!dd->kernel_send_context[i + 1])
2020 			goto nomem;
2021 		hfi1_init_ctxt(dd->kernel_send_context[i + 1]);
2022 	}
2023 
2024 	sc_enable(dd->vld[15].sc);
2025 	ctxt = dd->vld[15].sc->hw_context;
2026 	mask = all_vl_mask & ~(1LL << 15);
2027 	write_kctxt_csr(dd, ctxt, SC(CHECK_VL), mask);
2028 	dd_dev_info(dd,
2029 		    "Using send context %u(%u) for VL15\n",
2030 		    dd->vld[15].sc->sw_index, ctxt);
2031 
2032 	for (i = 0; i < num_vls; i++) {
2033 		sc_enable(dd->vld[i].sc);
2034 		ctxt = dd->vld[i].sc->hw_context;
2035 		mask = all_vl_mask & ~(data_vls_mask);
2036 		write_kctxt_csr(dd, ctxt, SC(CHECK_VL), mask);
2037 	}
2038 	for (i = num_vls; i < INIT_SC_PER_VL * num_vls; i++) {
2039 		sc_enable(dd->kernel_send_context[i + 1]);
2040 		ctxt = dd->kernel_send_context[i + 1]->hw_context;
2041 		mask = all_vl_mask & ~(data_vls_mask);
2042 		write_kctxt_csr(dd, ctxt, SC(CHECK_VL), mask);
2043 	}
2044 
2045 	if (pio_map_init(dd, ppd->port - 1, num_vls, NULL))
2046 		goto nomem;
2047 	return 0;
2048 
2049 nomem:
2050 	for (i = 0; i < num_vls; i++) {
2051 		sc_free(dd->vld[i].sc);
2052 		dd->vld[i].sc = NULL;
2053 	}
2054 
2055 	for (i = num_vls; i < INIT_SC_PER_VL * num_vls; i++)
2056 		sc_free(dd->kernel_send_context[i + 1]);
2057 
2058 	kfree(dd->kernel_send_context);
2059 	dd->kernel_send_context = NULL;
2060 
2061 freesc15:
2062 	sc_free(dd->vld[15].sc);
2063 	return -ENOMEM;
2064 }
2065 
init_credit_return(struct hfi1_devdata * dd)2066 int init_credit_return(struct hfi1_devdata *dd)
2067 {
2068 	int ret;
2069 	int i;
2070 
2071 	dd->cr_base = kcalloc(
2072 		node_affinity.num_possible_nodes,
2073 		sizeof(struct credit_return_base),
2074 		GFP_KERNEL);
2075 	if (!dd->cr_base) {
2076 		ret = -ENOMEM;
2077 		goto done;
2078 	}
2079 	for_each_node_with_cpus(i) {
2080 		int bytes = TXE_NUM_CONTEXTS * sizeof(struct credit_return);
2081 
2082 		set_dev_node(&dd->pcidev->dev, i);
2083 		dd->cr_base[i].va = dma_alloc_coherent(&dd->pcidev->dev,
2084 						       bytes,
2085 						       &dd->cr_base[i].dma,
2086 						       GFP_KERNEL);
2087 		if (!dd->cr_base[i].va) {
2088 			set_dev_node(&dd->pcidev->dev, dd->node);
2089 			dd_dev_err(dd,
2090 				   "Unable to allocate credit return DMA range for NUMA %d\n",
2091 				   i);
2092 			ret = -ENOMEM;
2093 			goto done;
2094 		}
2095 	}
2096 	set_dev_node(&dd->pcidev->dev, dd->node);
2097 
2098 	ret = 0;
2099 done:
2100 	return ret;
2101 }
2102 
free_credit_return(struct hfi1_devdata * dd)2103 void free_credit_return(struct hfi1_devdata *dd)
2104 {
2105 	int i;
2106 
2107 	if (!dd->cr_base)
2108 		return;
2109 	for (i = 0; i < node_affinity.num_possible_nodes; i++) {
2110 		if (dd->cr_base[i].va) {
2111 			dma_free_coherent(&dd->pcidev->dev,
2112 					  TXE_NUM_CONTEXTS *
2113 					  sizeof(struct credit_return),
2114 					  dd->cr_base[i].va,
2115 					  dd->cr_base[i].dma);
2116 		}
2117 	}
2118 	kfree(dd->cr_base);
2119 	dd->cr_base = NULL;
2120 }
2121 
seqfile_dump_sci(struct seq_file * s,u32 i,struct send_context_info * sci)2122 void seqfile_dump_sci(struct seq_file *s, u32 i,
2123 		      struct send_context_info *sci)
2124 {
2125 	struct send_context *sc = sci->sc;
2126 	u64 reg;
2127 
2128 	seq_printf(s, "SCI %u: type %u base %u credits %u\n",
2129 		   i, sci->type, sci->base, sci->credits);
2130 	seq_printf(s, "  flags 0x%x sw_inx %u hw_ctxt %u grp %u\n",
2131 		   sc->flags,  sc->sw_index, sc->hw_context, sc->group);
2132 	seq_printf(s, "  sr_size %u credits %u sr_head %u sr_tail %u\n",
2133 		   sc->sr_size, sc->credits, sc->sr_head, sc->sr_tail);
2134 	seq_printf(s, "  fill %lu free %lu fill_wrap %u alloc_free %lu\n",
2135 		   sc->fill, sc->free, sc->fill_wrap, sc->alloc_free);
2136 	seq_printf(s, "  credit_intr_count %u credit_ctrl 0x%llx\n",
2137 		   sc->credit_intr_count, sc->credit_ctrl);
2138 	reg = read_kctxt_csr(sc->dd, sc->hw_context, SC(CREDIT_STATUS));
2139 	seq_printf(s, "  *hw_free %llu CurrentFree %llu LastReturned %llu\n",
2140 		   (le64_to_cpu(*sc->hw_free) & CR_COUNTER_SMASK) >>
2141 		    CR_COUNTER_SHIFT,
2142 		   (reg >> SC(CREDIT_STATUS_CURRENT_FREE_COUNTER_SHIFT)) &
2143 		    SC(CREDIT_STATUS_CURRENT_FREE_COUNTER_MASK),
2144 		   reg & SC(CREDIT_STATUS_LAST_RETURNED_COUNTER_SMASK));
2145 }
2146