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