xref: /linux/tools/perf/util/arm-spe-decoder/arm-spe-decoder.c (revision 4f9786035f9e519db41375818e1d0b5f20da2f10)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * arm_spe_decoder.c: ARM SPE support
4  */
5 
6 #ifndef _GNU_SOURCE
7 #define _GNU_SOURCE
8 #endif
9 #include <errno.h>
10 #include <inttypes.h>
11 #include <stdbool.h>
12 #include <string.h>
13 #include <stdint.h>
14 #include <stdlib.h>
15 #include <linux/bitops.h>
16 #include <linux/compiler.h>
17 #include <linux/zalloc.h>
18 
19 #include "../auxtrace.h"
20 #include "../debug.h"
21 #include "../util.h"
22 
23 #include "arm-spe-decoder.h"
24 
25 static u64 arm_spe_calc_ip(int index, u64 payload)
26 {
27 	u64 ns, el, val;
28 
29 	/* Instruction virtual address or Branch target address */
30 	if (index == SPE_ADDR_PKT_HDR_INDEX_INS ||
31 	    index == SPE_ADDR_PKT_HDR_INDEX_BRANCH ||
32 	    index == SPE_ADDR_PKT_HDR_INDEX_PREV_BRANCH) {
33 		ns = SPE_ADDR_PKT_GET_NS(payload);
34 		el = SPE_ADDR_PKT_GET_EL(payload);
35 
36 		/* Clean highest byte */
37 		payload = SPE_ADDR_PKT_ADDR_GET_BYTES_0_6(payload);
38 
39 		/* Fill highest byte for EL1 or EL2 (VHE) mode */
40 		if (ns && (el == SPE_ADDR_PKT_EL1 || el == SPE_ADDR_PKT_EL2))
41 			payload |= 0xffULL << SPE_ADDR_PKT_ADDR_BYTE7_SHIFT;
42 
43 	/* Data access virtual address */
44 	} else if (index == SPE_ADDR_PKT_HDR_INDEX_DATA_VIRT) {
45 
46 		/* Clean tags */
47 		payload = SPE_ADDR_PKT_ADDR_GET_BYTES_0_6(payload);
48 
49 		/*
50 		 * Armv8 ARM (ARM DDI 0487F.c), chapter "D10.2.1 Address packet"
51 		 * defines the data virtual address payload format, the top byte
52 		 * (bits [63:56]) is assigned as top-byte tag; so we only can
53 		 * retrieve address value from bits [55:0].
54 		 *
55 		 * According to Documentation/arch/arm64/memory.rst, if detects the
56 		 * specific pattern in bits [55:52] of payload which falls in
57 		 * the kernel space, should fixup the top byte and this allows
58 		 * perf tool to parse DSO symbol for data address correctly.
59 		 *
60 		 * For this reason, if detects the bits [55:52] is 0xf, will
61 		 * fill 0xff into the top byte.
62 		 */
63 		val = SPE_ADDR_PKT_ADDR_GET_BYTE_6(payload);
64 		if ((val & 0xf0ULL) == 0xf0ULL)
65 			payload |= 0xffULL << SPE_ADDR_PKT_ADDR_BYTE7_SHIFT;
66 
67 	/* Data access physical address */
68 	} else if (index == SPE_ADDR_PKT_HDR_INDEX_DATA_PHYS) {
69 		/* Clean highest byte */
70 		payload = SPE_ADDR_PKT_ADDR_GET_BYTES_0_6(payload);
71 	} else {
72 		static u32 seen_idx = 0;
73 		if (!(seen_idx & BIT(index))) {
74 			seen_idx |= BIT(index);
75 			pr_warning("ignoring unsupported address packet index: 0x%x\n", index);
76 		}
77 	}
78 
79 	return payload;
80 }
81 
82 struct arm_spe_decoder *arm_spe_decoder_new(struct arm_spe_params *params)
83 {
84 	struct arm_spe_decoder *decoder;
85 
86 	if (!params->get_trace)
87 		return NULL;
88 
89 	decoder = zalloc(sizeof(struct arm_spe_decoder));
90 	if (!decoder)
91 		return NULL;
92 
93 	decoder->get_trace = params->get_trace;
94 	decoder->data = params->data;
95 
96 	return decoder;
97 }
98 
99 void arm_spe_decoder_free(struct arm_spe_decoder *decoder)
100 {
101 	free(decoder);
102 }
103 
104 static int arm_spe_get_data(struct arm_spe_decoder *decoder)
105 {
106 	struct arm_spe_buffer buffer = { .buf = 0, };
107 	int ret;
108 
109 	pr_debug("Getting more data\n");
110 	ret = decoder->get_trace(&buffer, decoder->data);
111 	if (ret < 0)
112 		return ret;
113 
114 	decoder->buf = buffer.buf;
115 	decoder->len = buffer.len;
116 
117 	if (!decoder->len)
118 		pr_debug("No more data\n");
119 
120 	return decoder->len;
121 }
122 
123 static int arm_spe_get_next_packet(struct arm_spe_decoder *decoder)
124 {
125 	int ret;
126 
127 	do {
128 		if (!decoder->len) {
129 			ret = arm_spe_get_data(decoder);
130 
131 			/* Failed to read out trace data */
132 			if (ret <= 0)
133 				return ret;
134 		}
135 
136 		ret = arm_spe_get_packet(decoder->buf, decoder->len,
137 					 &decoder->packet);
138 		if (ret <= 0) {
139 			/* Move forward for 1 byte */
140 			decoder->buf += 1;
141 			decoder->len -= 1;
142 			return -EBADMSG;
143 		}
144 
145 		decoder->buf += ret;
146 		decoder->len -= ret;
147 	} while (decoder->packet.type == ARM_SPE_PAD);
148 
149 	return 1;
150 }
151 
152 static int arm_spe_read_record(struct arm_spe_decoder *decoder)
153 {
154 	int err;
155 	int idx;
156 	u64 payload, ip;
157 
158 	memset(&decoder->record, 0x0, sizeof(decoder->record));
159 	decoder->record.context_id = (u64)-1;
160 
161 	while (1) {
162 		err = arm_spe_get_next_packet(decoder);
163 		if (err <= 0)
164 			return err;
165 
166 		idx = decoder->packet.index;
167 		payload = decoder->packet.payload;
168 
169 		switch (decoder->packet.type) {
170 		case ARM_SPE_TIMESTAMP:
171 			decoder->record.timestamp = payload;
172 			return 1;
173 		case ARM_SPE_END:
174 			return 1;
175 		case ARM_SPE_ADDRESS:
176 			ip = arm_spe_calc_ip(idx, payload);
177 			if (idx == SPE_ADDR_PKT_HDR_INDEX_INS)
178 				decoder->record.from_ip = ip;
179 			else if (idx == SPE_ADDR_PKT_HDR_INDEX_BRANCH)
180 				decoder->record.to_ip = ip;
181 			else if (idx == SPE_ADDR_PKT_HDR_INDEX_DATA_VIRT)
182 				decoder->record.virt_addr = ip;
183 			else if (idx == SPE_ADDR_PKT_HDR_INDEX_DATA_PHYS)
184 				decoder->record.phys_addr = ip;
185 			else if (idx == SPE_ADDR_PKT_HDR_INDEX_PREV_BRANCH)
186 				decoder->record.prev_br_tgt = ip;
187 			break;
188 		case ARM_SPE_COUNTER:
189 			if (idx == SPE_CNT_PKT_HDR_INDEX_TOTAL_LAT)
190 				decoder->record.latency = payload;
191 			break;
192 		case ARM_SPE_CONTEXT:
193 			decoder->record.context_id = payload;
194 			break;
195 		case ARM_SPE_OP_TYPE:
196 			switch (idx) {
197 			case SPE_OP_PKT_HDR_CLASS_LD_ST_ATOMIC:
198 				decoder->record.op |= ARM_SPE_OP_LDST;
199 				if (payload & SPE_OP_PKT_ST)
200 					decoder->record.op |= ARM_SPE_OP_ST;
201 				else
202 					decoder->record.op |= ARM_SPE_OP_LD;
203 				if (SPE_OP_PKT_IS_LDST_SVE(payload))
204 					decoder->record.op |= ARM_SPE_OP_SVE_LDST;
205 				break;
206 			case SPE_OP_PKT_HDR_CLASS_OTHER:
207 				decoder->record.op |= ARM_SPE_OP_OTHER;
208 				if (SPE_OP_PKT_IS_OTHER_SVE_OP(payload))
209 					decoder->record.op |= ARM_SPE_OP_SVE_OTHER;
210 				break;
211 			case SPE_OP_PKT_HDR_CLASS_BR_ERET:
212 				decoder->record.op |= ARM_SPE_OP_BRANCH_ERET;
213 				if (payload & SPE_OP_PKT_COND)
214 					decoder->record.op |= ARM_SPE_OP_BR_COND;
215 				if (payload & SPE_OP_PKT_INDIRECT_BRANCH)
216 					decoder->record.op |= ARM_SPE_OP_BR_INDIRECT;
217 				if (payload & SPE_OP_PKT_GCS)
218 					decoder->record.op |= ARM_SPE_OP_BR_GCS;
219 				if (SPE_OP_PKT_CR_BL(payload))
220 					decoder->record.op |= ARM_SPE_OP_BR_CR_BL;
221 				if (SPE_OP_PKT_CR_RET(payload))
222 					decoder->record.op |= ARM_SPE_OP_BR_CR_RET;
223 				if (SPE_OP_PKT_CR_NON_BL_RET(payload))
224 					decoder->record.op |= ARM_SPE_OP_BR_CR_NON_BL_RET;
225 				break;
226 			default:
227 				pr_err("Get packet error!\n");
228 				return -1;
229 			}
230 			break;
231 		case ARM_SPE_EVENTS:
232 			if (payload & BIT(EV_L1D_REFILL))
233 				decoder->record.type |= ARM_SPE_L1D_MISS;
234 
235 			if (payload & BIT(EV_L1D_ACCESS))
236 				decoder->record.type |= ARM_SPE_L1D_ACCESS;
237 
238 			if (payload & BIT(EV_TLB_WALK))
239 				decoder->record.type |= ARM_SPE_TLB_MISS;
240 
241 			if (payload & BIT(EV_TLB_ACCESS))
242 				decoder->record.type |= ARM_SPE_TLB_ACCESS;
243 
244 			if (payload & BIT(EV_LLC_MISS))
245 				decoder->record.type |= ARM_SPE_LLC_MISS;
246 
247 			if (payload & BIT(EV_LLC_ACCESS))
248 				decoder->record.type |= ARM_SPE_LLC_ACCESS;
249 
250 			if (payload & BIT(EV_REMOTE_ACCESS))
251 				decoder->record.type |= ARM_SPE_REMOTE_ACCESS;
252 
253 			if (payload & BIT(EV_MISPRED))
254 				decoder->record.type |= ARM_SPE_BRANCH_MISS;
255 
256 			if (payload & BIT(EV_NOT_TAKEN))
257 				decoder->record.type |= ARM_SPE_BRANCH_NOT_TAKEN;
258 
259 			if (payload & BIT(EV_TRANSACTIONAL))
260 				decoder->record.type |= ARM_SPE_IN_TXN;
261 
262 			if (payload & BIT(EV_PARTIAL_PREDICATE))
263 				decoder->record.type |= ARM_SPE_SVE_PARTIAL_PRED;
264 
265 			if (payload & BIT(EV_EMPTY_PREDICATE))
266 				decoder->record.type |= ARM_SPE_SVE_EMPTY_PRED;
267 
268 			break;
269 		case ARM_SPE_DATA_SOURCE:
270 			decoder->record.source = payload;
271 			break;
272 		case ARM_SPE_BAD:
273 			break;
274 		case ARM_SPE_PAD:
275 			break;
276 		default:
277 			pr_err("Get packet error!\n");
278 			return -1;
279 		}
280 	}
281 
282 	return 0;
283 }
284 
285 int arm_spe_decode(struct arm_spe_decoder *decoder)
286 {
287 	return arm_spe_read_record(decoder);
288 }
289