xref: /linux/tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.c (revision 4f9786035f9e519db41375818e1d0b5f20da2f10)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Arm Statistical Profiling Extensions (SPE) support
4  * Copyright (c) 2017-2018, Arm Ltd.
5  */
6 
7 #include <stdio.h>
8 #include <string.h>
9 #include <endian.h>
10 #include <byteswap.h>
11 #include <linux/bitops.h>
12 #include <stdarg.h>
13 #include <linux/kernel.h>
14 #include <linux/unaligned.h>
15 
16 #include "arm-spe-pkt-decoder.h"
17 
18 static const char * const arm_spe_packet_name[] = {
19 	[ARM_SPE_PAD]		= "PAD",
20 	[ARM_SPE_END]		= "END",
21 	[ARM_SPE_TIMESTAMP]	= "TS",
22 	[ARM_SPE_ADDRESS]	= "ADDR",
23 	[ARM_SPE_COUNTER]	= "LAT",
24 	[ARM_SPE_CONTEXT]	= "CONTEXT",
25 	[ARM_SPE_OP_TYPE]	= "OP-TYPE",
26 	[ARM_SPE_EVENTS]	= "EVENTS",
27 	[ARM_SPE_DATA_SOURCE]	= "DATA-SOURCE",
28 };
29 
30 const char *arm_spe_pkt_name(enum arm_spe_pkt_type type)
31 {
32 	return arm_spe_packet_name[type];
33 }
34 
35 /*
36  * Extracts the field "sz" from header bits and converts to bytes:
37  *   00 : byte (1)
38  *   01 : halfword (2)
39  *   10 : word (4)
40  *   11 : doubleword (8)
41  */
42 static unsigned int arm_spe_payload_len(unsigned char hdr)
43 {
44 	return 1U << ((hdr & GENMASK_ULL(5, 4)) >> 4);
45 }
46 
47 static int arm_spe_get_payload(const unsigned char *buf, size_t len,
48 			       unsigned char ext_hdr,
49 			       struct arm_spe_pkt *packet)
50 {
51 	size_t payload_len = arm_spe_payload_len(buf[ext_hdr]);
52 
53 	if (len < 1 + ext_hdr + payload_len)
54 		return ARM_SPE_NEED_MORE_BYTES;
55 
56 	buf += 1 + ext_hdr;
57 
58 	switch (payload_len) {
59 	case 1: packet->payload = *(uint8_t *)buf; break;
60 	case 2: packet->payload = get_unaligned_le16(buf); break;
61 	case 4: packet->payload = get_unaligned_le32(buf); break;
62 	case 8: packet->payload = get_unaligned_le64(buf); break;
63 	default: return ARM_SPE_BAD_PACKET;
64 	}
65 
66 	return 1 + ext_hdr + payload_len;
67 }
68 
69 static int arm_spe_get_pad(struct arm_spe_pkt *packet)
70 {
71 	packet->type = ARM_SPE_PAD;
72 	return 1;
73 }
74 
75 static int arm_spe_get_alignment(const unsigned char *buf, size_t len,
76 				 struct arm_spe_pkt *packet)
77 {
78 	unsigned int alignment = 1 << ((buf[0] & 0xf) + 1);
79 
80 	if (len < alignment)
81 		return ARM_SPE_NEED_MORE_BYTES;
82 
83 	packet->type = ARM_SPE_PAD;
84 	return alignment - (((uintptr_t)buf) & (alignment - 1));
85 }
86 
87 static int arm_spe_get_end(struct arm_spe_pkt *packet)
88 {
89 	packet->type = ARM_SPE_END;
90 	return 1;
91 }
92 
93 static int arm_spe_get_timestamp(const unsigned char *buf, size_t len,
94 				 struct arm_spe_pkt *packet)
95 {
96 	packet->type = ARM_SPE_TIMESTAMP;
97 	return arm_spe_get_payload(buf, len, 0, packet);
98 }
99 
100 static int arm_spe_get_events(const unsigned char *buf, size_t len,
101 			      struct arm_spe_pkt *packet)
102 {
103 	packet->type = ARM_SPE_EVENTS;
104 
105 	/* we use index to identify Events with a less number of
106 	 * comparisons in arm_spe_pkt_desc(): E.g., the LLC-ACCESS,
107 	 * LLC-REFILL, and REMOTE-ACCESS events are identified if
108 	 * index > 1.
109 	 */
110 	packet->index = arm_spe_payload_len(buf[0]);
111 
112 	return arm_spe_get_payload(buf, len, 0, packet);
113 }
114 
115 static int arm_spe_get_data_source(const unsigned char *buf, size_t len,
116 				   struct arm_spe_pkt *packet)
117 {
118 	packet->type = ARM_SPE_DATA_SOURCE;
119 	return arm_spe_get_payload(buf, len, 0, packet);
120 }
121 
122 static int arm_spe_get_context(const unsigned char *buf, size_t len,
123 			       struct arm_spe_pkt *packet)
124 {
125 	packet->type = ARM_SPE_CONTEXT;
126 	packet->index = SPE_CTX_PKT_HDR_INDEX(buf[0]);
127 	return arm_spe_get_payload(buf, len, 0, packet);
128 }
129 
130 static int arm_spe_get_op_type(const unsigned char *buf, size_t len,
131 			       struct arm_spe_pkt *packet)
132 {
133 	packet->type = ARM_SPE_OP_TYPE;
134 	packet->index = SPE_OP_PKT_HDR_CLASS(buf[0]);
135 	return arm_spe_get_payload(buf, len, 0, packet);
136 }
137 
138 static int arm_spe_get_counter(const unsigned char *buf, size_t len,
139 			       const unsigned char ext_hdr, struct arm_spe_pkt *packet)
140 {
141 	packet->type = ARM_SPE_COUNTER;
142 
143 	if (ext_hdr)
144 		packet->index = SPE_HDR_EXTENDED_INDEX(buf[0], buf[1]);
145 	else
146 		packet->index = SPE_HDR_SHORT_INDEX(buf[0]);
147 
148 	return arm_spe_get_payload(buf, len, ext_hdr, packet);
149 }
150 
151 static int arm_spe_get_addr(const unsigned char *buf, size_t len,
152 			    const unsigned char ext_hdr, struct arm_spe_pkt *packet)
153 {
154 	packet->type = ARM_SPE_ADDRESS;
155 
156 	if (ext_hdr)
157 		packet->index = SPE_HDR_EXTENDED_INDEX(buf[0], buf[1]);
158 	else
159 		packet->index = SPE_HDR_SHORT_INDEX(buf[0]);
160 
161 	return arm_spe_get_payload(buf, len, ext_hdr, packet);
162 }
163 
164 static int arm_spe_do_get_packet(const unsigned char *buf, size_t len,
165 				 struct arm_spe_pkt *packet)
166 {
167 	unsigned int hdr;
168 	unsigned char ext_hdr = 0;
169 
170 	memset(packet, 0, sizeof(struct arm_spe_pkt));
171 
172 	if (!len)
173 		return ARM_SPE_NEED_MORE_BYTES;
174 
175 	hdr = buf[0];
176 
177 	if (hdr == SPE_HEADER0_PAD)
178 		return arm_spe_get_pad(packet);
179 
180 	if (hdr == SPE_HEADER0_END) /* no timestamp at end of record */
181 		return arm_spe_get_end(packet);
182 
183 	if (hdr == SPE_HEADER0_TIMESTAMP)
184 		return arm_spe_get_timestamp(buf, len, packet);
185 
186 	if ((hdr & SPE_HEADER0_MASK1) == SPE_HEADER0_EVENTS)
187 		return arm_spe_get_events(buf, len, packet);
188 
189 	if ((hdr & SPE_HEADER0_MASK1) == SPE_HEADER0_SOURCE)
190 		return arm_spe_get_data_source(buf, len, packet);
191 
192 	if ((hdr & SPE_HEADER0_MASK2) == SPE_HEADER0_CONTEXT)
193 		return arm_spe_get_context(buf, len, packet);
194 
195 	if ((hdr & SPE_HEADER0_MASK2) == SPE_HEADER0_OP_TYPE)
196 		return arm_spe_get_op_type(buf, len, packet);
197 
198 	if ((hdr & SPE_HEADER0_MASK2) == SPE_HEADER0_EXTENDED) {
199 		/* 16-bit extended format header */
200 		if (len == 1)
201 			return ARM_SPE_BAD_PACKET;
202 
203 		ext_hdr = 1;
204 		hdr = buf[1];
205 		if (hdr == SPE_HEADER1_ALIGNMENT)
206 			return arm_spe_get_alignment(buf, len, packet);
207 	}
208 
209 	/*
210 	 * The short format header's byte 0 or the extended format header's
211 	 * byte 1 has been assigned to 'hdr', which uses the same encoding for
212 	 * address packet and counter packet, so don't need to distinguish if
213 	 * it's short format or extended format and handle in once.
214 	 */
215 	if ((hdr & SPE_HEADER0_MASK3) == SPE_HEADER0_ADDRESS)
216 		return arm_spe_get_addr(buf, len, ext_hdr, packet);
217 
218 	if ((hdr & SPE_HEADER0_MASK3) == SPE_HEADER0_COUNTER)
219 		return arm_spe_get_counter(buf, len, ext_hdr, packet);
220 
221 	return ARM_SPE_BAD_PACKET;
222 }
223 
224 int arm_spe_get_packet(const unsigned char *buf, size_t len,
225 		       struct arm_spe_pkt *packet)
226 {
227 	int ret;
228 
229 	ret = arm_spe_do_get_packet(buf, len, packet);
230 	/* put multiple consecutive PADs on the same line, up to
231 	 * the fixed-width output format of 16 bytes per line.
232 	 */
233 	if (ret > 0 && packet->type == ARM_SPE_PAD) {
234 		while (ret < 16 && len > (size_t)ret && !buf[ret])
235 			ret += 1;
236 	}
237 	return ret;
238 }
239 
240 static int arm_spe_pkt_out_string(int *err, char **buf_p, size_t *blen,
241 				  const char *fmt, ...)
242 {
243 	va_list ap;
244 	int ret;
245 
246 	/* Bail out if any error occurred */
247 	if (err && *err)
248 		return *err;
249 
250 	va_start(ap, fmt);
251 	ret = vsnprintf(*buf_p, *blen, fmt, ap);
252 	va_end(ap);
253 
254 	if (ret < 0) {
255 		if (err && !*err)
256 			*err = ret;
257 
258 	/*
259 	 * A return value of *blen or more means that the output was
260 	 * truncated and the buffer is overrun.
261 	 */
262 	} else if ((size_t)ret >= *blen) {
263 		(*buf_p)[*blen - 1] = '\0';
264 
265 		/*
266 		 * Set *err to 'ret' to avoid overflow if tries to
267 		 * fill this buffer sequentially.
268 		 */
269 		if (err && !*err)
270 			*err = ret;
271 	} else {
272 		*buf_p += ret;
273 		*blen -= ret;
274 	}
275 
276 	return ret;
277 }
278 
279 static int arm_spe_pkt_desc_event(const struct arm_spe_pkt *packet,
280 				  char *buf, size_t buf_len)
281 {
282 	u64 payload = packet->payload;
283 	int err = 0;
284 
285 	arm_spe_pkt_out_string(&err, &buf, &buf_len, "EV");
286 
287 	if (payload & BIT(EV_EXCEPTION_GEN))
288 		arm_spe_pkt_out_string(&err, &buf, &buf_len, " EXCEPTION-GEN");
289 	if (payload & BIT(EV_RETIRED))
290 		arm_spe_pkt_out_string(&err, &buf, &buf_len, " RETIRED");
291 	if (payload & BIT(EV_L1D_ACCESS))
292 		arm_spe_pkt_out_string(&err, &buf, &buf_len, " L1D-ACCESS");
293 	if (payload & BIT(EV_L1D_REFILL))
294 		arm_spe_pkt_out_string(&err, &buf, &buf_len, " L1D-REFILL");
295 	if (payload & BIT(EV_TLB_ACCESS))
296 		arm_spe_pkt_out_string(&err, &buf, &buf_len, " TLB-ACCESS");
297 	if (payload & BIT(EV_TLB_WALK))
298 		arm_spe_pkt_out_string(&err, &buf, &buf_len, " TLB-REFILL");
299 	if (payload & BIT(EV_NOT_TAKEN))
300 		arm_spe_pkt_out_string(&err, &buf, &buf_len, " NOT-TAKEN");
301 	if (payload & BIT(EV_MISPRED))
302 		arm_spe_pkt_out_string(&err, &buf, &buf_len, " MISPRED");
303 	if (payload & BIT(EV_LLC_ACCESS))
304 		arm_spe_pkt_out_string(&err, &buf, &buf_len, " LLC-ACCESS");
305 	if (payload & BIT(EV_LLC_MISS))
306 		arm_spe_pkt_out_string(&err, &buf, &buf_len, " LLC-REFILL");
307 	if (payload & BIT(EV_REMOTE_ACCESS))
308 		arm_spe_pkt_out_string(&err, &buf, &buf_len, " REMOTE-ACCESS");
309 	if (payload & BIT(EV_ALIGNMENT))
310 		arm_spe_pkt_out_string(&err, &buf, &buf_len, " ALIGNMENT");
311 	if (payload & BIT(EV_TRANSACTIONAL))
312 		arm_spe_pkt_out_string(&err, &buf, &buf_len, " TXN");
313 	if (payload & BIT(EV_PARTIAL_PREDICATE))
314 		arm_spe_pkt_out_string(&err, &buf, &buf_len, " SVE-PARTIAL-PRED");
315 	if (payload & BIT(EV_EMPTY_PREDICATE))
316 		arm_spe_pkt_out_string(&err, &buf, &buf_len, " SVE-EMPTY-PRED");
317 
318 	return err;
319 }
320 
321 static int arm_spe_pkt_desc_op_type(const struct arm_spe_pkt *packet,
322 				    char *buf, size_t buf_len)
323 {
324 	u64 payload = packet->payload;
325 	int err = 0;
326 
327 	switch (packet->index) {
328 	case SPE_OP_PKT_HDR_CLASS_OTHER:
329 		if (SPE_OP_PKT_IS_OTHER_SVE_OP(payload)) {
330 			arm_spe_pkt_out_string(&err, &buf, &buf_len, "SVE-OTHER");
331 
332 			/* SVE effective vector length */
333 			arm_spe_pkt_out_string(&err, &buf, &buf_len, " EVLEN %d",
334 					       SPE_OP_PKG_SVE_EVL(payload));
335 
336 			if (payload & SPE_OP_PKT_SVE_FP)
337 				arm_spe_pkt_out_string(&err, &buf, &buf_len, " FP");
338 			if (payload & SPE_OP_PKT_SVE_PRED)
339 				arm_spe_pkt_out_string(&err, &buf, &buf_len, " PRED");
340 		} else {
341 			arm_spe_pkt_out_string(&err, &buf, &buf_len, "OTHER");
342 			arm_spe_pkt_out_string(&err, &buf, &buf_len, " %s",
343 					       payload & SPE_OP_PKT_COND ?
344 					       "COND-SELECT" : "INSN-OTHER");
345 		}
346 		break;
347 	case SPE_OP_PKT_HDR_CLASS_LD_ST_ATOMIC:
348 		arm_spe_pkt_out_string(&err, &buf, &buf_len,
349 				       payload & 0x1 ? "ST" : "LD");
350 
351 		if (SPE_OP_PKT_IS_LDST_ATOMIC(payload)) {
352 			if (payload & SPE_OP_PKT_AT)
353 				arm_spe_pkt_out_string(&err, &buf, &buf_len, " AT");
354 			if (payload & SPE_OP_PKT_EXCL)
355 				arm_spe_pkt_out_string(&err, &buf, &buf_len, " EXCL");
356 			if (payload & SPE_OP_PKT_AR)
357 				arm_spe_pkt_out_string(&err, &buf, &buf_len, " AR");
358 		}
359 
360 		switch (SPE_OP_PKT_LDST_SUBCLASS_GET(payload)) {
361 		case SPE_OP_PKT_LDST_SUBCLASS_SIMD_FP:
362 			arm_spe_pkt_out_string(&err, &buf, &buf_len, " SIMD-FP");
363 			break;
364 		case SPE_OP_PKT_LDST_SUBCLASS_GP_REG:
365 			arm_spe_pkt_out_string(&err, &buf, &buf_len, " GP-REG");
366 			break;
367 		case SPE_OP_PKT_LDST_SUBCLASS_UNSPEC_REG:
368 			arm_spe_pkt_out_string(&err, &buf, &buf_len, " UNSPEC-REG");
369 			break;
370 		case SPE_OP_PKT_LDST_SUBCLASS_NV_SYSREG:
371 			arm_spe_pkt_out_string(&err, &buf, &buf_len, " NV-SYSREG");
372 			break;
373 		case SPE_OP_PKT_LDST_SUBCLASS_MTE_TAG:
374 			arm_spe_pkt_out_string(&err, &buf, &buf_len, " MTE-TAG");
375 			break;
376 		case SPE_OP_PKT_LDST_SUBCLASS_MEMCPY:
377 			arm_spe_pkt_out_string(&err, &buf, &buf_len, " MEMCPY");
378 			break;
379 		case SPE_OP_PKT_LDST_SUBCLASS_MEMSET:
380 			arm_spe_pkt_out_string(&err, &buf, &buf_len, " MEMSET");
381 			break;
382 		default:
383 			break;
384 		}
385 
386 		if (SPE_OP_PKT_IS_LDST_SVE(payload)) {
387 			/* SVE effective vector length */
388 			arm_spe_pkt_out_string(&err, &buf, &buf_len, " EVLEN %d",
389 					       SPE_OP_PKG_SVE_EVL(payload));
390 
391 			if (payload & SPE_OP_PKT_SVE_PRED)
392 				arm_spe_pkt_out_string(&err, &buf, &buf_len, " PRED");
393 			if (payload & SPE_OP_PKT_SVE_SG)
394 				arm_spe_pkt_out_string(&err, &buf, &buf_len, " SG");
395 		}
396 		break;
397 	case SPE_OP_PKT_HDR_CLASS_BR_ERET:
398 		arm_spe_pkt_out_string(&err, &buf, &buf_len, "B");
399 
400 		if (payload & SPE_OP_PKT_COND)
401 			arm_spe_pkt_out_string(&err, &buf, &buf_len, " COND");
402 		if (payload & SPE_OP_PKT_INDIRECT_BRANCH)
403 			arm_spe_pkt_out_string(&err, &buf, &buf_len, " IND");
404 		if (payload & SPE_OP_PKT_GCS)
405 			arm_spe_pkt_out_string(&err, &buf, &buf_len, " GCS");
406 		if (SPE_OP_PKT_CR_BL(payload))
407 			arm_spe_pkt_out_string(&err, &buf, &buf_len, " CR-BL");
408 		if (SPE_OP_PKT_CR_RET(payload))
409 			arm_spe_pkt_out_string(&err, &buf, &buf_len, " CR-RET");
410 		if (SPE_OP_PKT_CR_NON_BL_RET(payload))
411 			arm_spe_pkt_out_string(&err, &buf, &buf_len, " CR-NON-BL-RET");
412 		break;
413 	default:
414 		/* Unknown index */
415 		err = -1;
416 		break;
417 	}
418 
419 	return err;
420 }
421 
422 static int arm_spe_pkt_desc_addr(const struct arm_spe_pkt *packet,
423 				 char *buf, size_t buf_len)
424 {
425 	int ns, el, idx = packet->index;
426 	int ch, pat;
427 	u64 payload = packet->payload;
428 	int err = 0;
429 	static const char *idx_name[] = {"PC", "TGT", "VA", "PA", "PBT"};
430 
431 	switch (idx) {
432 	case SPE_ADDR_PKT_HDR_INDEX_INS:
433 	case SPE_ADDR_PKT_HDR_INDEX_BRANCH:
434 	case SPE_ADDR_PKT_HDR_INDEX_PREV_BRANCH:
435 		ns = !!SPE_ADDR_PKT_GET_NS(payload);
436 		el = SPE_ADDR_PKT_GET_EL(payload);
437 		payload = SPE_ADDR_PKT_ADDR_GET_BYTES_0_6(payload);
438 		arm_spe_pkt_out_string(&err, &buf, &buf_len,
439 				"%s 0x%llx el%d ns=%d",
440 				idx_name[idx], payload, el, ns);
441 		break;
442 	case SPE_ADDR_PKT_HDR_INDEX_DATA_VIRT:
443 		arm_spe_pkt_out_string(&err, &buf, &buf_len,
444 				       "VA 0x%llx", payload);
445 		break;
446 	case SPE_ADDR_PKT_HDR_INDEX_DATA_PHYS:
447 		ns = !!SPE_ADDR_PKT_GET_NS(payload);
448 		ch = !!SPE_ADDR_PKT_GET_CH(payload);
449 		pat = SPE_ADDR_PKT_GET_PAT(payload);
450 		payload = SPE_ADDR_PKT_ADDR_GET_BYTES_0_6(payload);
451 		arm_spe_pkt_out_string(&err, &buf, &buf_len,
452 				       "PA 0x%llx ns=%d ch=%d pat=%x",
453 				       payload, ns, ch, pat);
454 		break;
455 	default:
456 		/* Unknown index */
457 		err = -1;
458 		break;
459 	}
460 
461 	return err;
462 }
463 
464 static int arm_spe_pkt_desc_counter(const struct arm_spe_pkt *packet,
465 				    char *buf, size_t buf_len)
466 {
467 	u64 payload = packet->payload;
468 	const char *name = arm_spe_pkt_name(packet->type);
469 	int err = 0;
470 
471 	arm_spe_pkt_out_string(&err, &buf, &buf_len, "%s %d ", name,
472 			       (unsigned short)payload);
473 
474 	switch (packet->index) {
475 	case SPE_CNT_PKT_HDR_INDEX_TOTAL_LAT:
476 		arm_spe_pkt_out_string(&err, &buf, &buf_len, "TOT");
477 		break;
478 	case SPE_CNT_PKT_HDR_INDEX_ISSUE_LAT:
479 		arm_spe_pkt_out_string(&err, &buf, &buf_len, "ISSUE");
480 		break;
481 	case SPE_CNT_PKT_HDR_INDEX_TRANS_LAT:
482 		arm_spe_pkt_out_string(&err, &buf, &buf_len, "XLAT");
483 		break;
484 	default:
485 		break;
486 	}
487 
488 	return err;
489 }
490 
491 int arm_spe_pkt_desc(const struct arm_spe_pkt *packet, char *buf,
492 		     size_t buf_len)
493 {
494 	int idx = packet->index;
495 	unsigned long long payload = packet->payload;
496 	const char *name = arm_spe_pkt_name(packet->type);
497 	char *buf_orig = buf;
498 	size_t blen = buf_len;
499 	int err = 0;
500 
501 	switch (packet->type) {
502 	case ARM_SPE_BAD:
503 	case ARM_SPE_PAD:
504 	case ARM_SPE_END:
505 		arm_spe_pkt_out_string(&err, &buf, &blen, "%s", name);
506 		break;
507 	case ARM_SPE_EVENTS:
508 		err = arm_spe_pkt_desc_event(packet, buf, buf_len);
509 		break;
510 	case ARM_SPE_OP_TYPE:
511 		err = arm_spe_pkt_desc_op_type(packet, buf, buf_len);
512 		break;
513 	case ARM_SPE_DATA_SOURCE:
514 	case ARM_SPE_TIMESTAMP:
515 		arm_spe_pkt_out_string(&err, &buf, &blen, "%s %lld", name, payload);
516 		break;
517 	case ARM_SPE_ADDRESS:
518 		err = arm_spe_pkt_desc_addr(packet, buf, buf_len);
519 		break;
520 	case ARM_SPE_CONTEXT:
521 		arm_spe_pkt_out_string(&err, &buf, &blen, "%s 0x%lx el%d",
522 				       name, (unsigned long)payload, idx + 1);
523 		break;
524 	case ARM_SPE_COUNTER:
525 		err = arm_spe_pkt_desc_counter(packet, buf, buf_len);
526 		break;
527 	default:
528 		/* Unknown packet type */
529 		err = -1;
530 		break;
531 	}
532 
533 	/* Output raw data if detect any error */
534 	if (err) {
535 		err = 0;
536 		arm_spe_pkt_out_string(&err, &buf_orig, &buf_len, "%s 0x%llx (%d)",
537 				       name, payload, packet->index);
538 	}
539 
540 	return err;
541 }
542