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 		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/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 		pr_err("unsupported address packet index: 0x%x\n", index);
72 	}
73 
74 	return payload;
75 }
76 
77 struct arm_spe_decoder *arm_spe_decoder_new(struct arm_spe_params *params)
78 {
79 	struct arm_spe_decoder *decoder;
80 
81 	if (!params->get_trace)
82 		return NULL;
83 
84 	decoder = zalloc(sizeof(struct arm_spe_decoder));
85 	if (!decoder)
86 		return NULL;
87 
88 	decoder->get_trace = params->get_trace;
89 	decoder->data = params->data;
90 
91 	return decoder;
92 }
93 
94 void arm_spe_decoder_free(struct arm_spe_decoder *decoder)
95 {
96 	free(decoder);
97 }
98 
99 static int arm_spe_get_data(struct arm_spe_decoder *decoder)
100 {
101 	struct arm_spe_buffer buffer = { .buf = 0, };
102 	int ret;
103 
104 	pr_debug("Getting more data\n");
105 	ret = decoder->get_trace(&buffer, decoder->data);
106 	if (ret < 0)
107 		return ret;
108 
109 	decoder->buf = buffer.buf;
110 	decoder->len = buffer.len;
111 
112 	if (!decoder->len)
113 		pr_debug("No more data\n");
114 
115 	return decoder->len;
116 }
117 
118 static int arm_spe_get_next_packet(struct arm_spe_decoder *decoder)
119 {
120 	int ret;
121 
122 	do {
123 		if (!decoder->len) {
124 			ret = arm_spe_get_data(decoder);
125 
126 			/* Failed to read out trace data */
127 			if (ret <= 0)
128 				return ret;
129 		}
130 
131 		ret = arm_spe_get_packet(decoder->buf, decoder->len,
132 					 &decoder->packet);
133 		if (ret <= 0) {
134 			/* Move forward for 1 byte */
135 			decoder->buf += 1;
136 			decoder->len -= 1;
137 			return -EBADMSG;
138 		}
139 
140 		decoder->buf += ret;
141 		decoder->len -= ret;
142 	} while (decoder->packet.type == ARM_SPE_PAD);
143 
144 	return 1;
145 }
146 
147 static int arm_spe_read_record(struct arm_spe_decoder *decoder)
148 {
149 	int err;
150 	int idx;
151 	u64 payload, ip;
152 
153 	memset(&decoder->record, 0x0, sizeof(decoder->record));
154 	decoder->record.context_id = (u64)-1;
155 
156 	while (1) {
157 		err = arm_spe_get_next_packet(decoder);
158 		if (err <= 0)
159 			return err;
160 
161 		idx = decoder->packet.index;
162 		payload = decoder->packet.payload;
163 
164 		switch (decoder->packet.type) {
165 		case ARM_SPE_TIMESTAMP:
166 			decoder->record.timestamp = payload;
167 			return 1;
168 		case ARM_SPE_END:
169 			return 1;
170 		case ARM_SPE_ADDRESS:
171 			ip = arm_spe_calc_ip(idx, payload);
172 			if (idx == SPE_ADDR_PKT_HDR_INDEX_INS)
173 				decoder->record.from_ip = ip;
174 			else if (idx == SPE_ADDR_PKT_HDR_INDEX_BRANCH)
175 				decoder->record.to_ip = ip;
176 			else if (idx == SPE_ADDR_PKT_HDR_INDEX_DATA_VIRT)
177 				decoder->record.virt_addr = ip;
178 			else if (idx == SPE_ADDR_PKT_HDR_INDEX_DATA_PHYS)
179 				decoder->record.phys_addr = ip;
180 			break;
181 		case ARM_SPE_COUNTER:
182 			break;
183 		case ARM_SPE_CONTEXT:
184 			decoder->record.context_id = payload;
185 			break;
186 		case ARM_SPE_OP_TYPE:
187 			if (idx == SPE_OP_PKT_HDR_CLASS_LD_ST_ATOMIC) {
188 				if (payload & 0x1)
189 					decoder->record.op = ARM_SPE_ST;
190 				else
191 					decoder->record.op = ARM_SPE_LD;
192 			}
193 			break;
194 		case ARM_SPE_EVENTS:
195 			if (payload & BIT(EV_L1D_REFILL))
196 				decoder->record.type |= ARM_SPE_L1D_MISS;
197 
198 			if (payload & BIT(EV_L1D_ACCESS))
199 				decoder->record.type |= ARM_SPE_L1D_ACCESS;
200 
201 			if (payload & BIT(EV_TLB_WALK))
202 				decoder->record.type |= ARM_SPE_TLB_MISS;
203 
204 			if (payload & BIT(EV_TLB_ACCESS))
205 				decoder->record.type |= ARM_SPE_TLB_ACCESS;
206 
207 			if (payload & BIT(EV_LLC_MISS))
208 				decoder->record.type |= ARM_SPE_LLC_MISS;
209 
210 			if (payload & BIT(EV_LLC_ACCESS))
211 				decoder->record.type |= ARM_SPE_LLC_ACCESS;
212 
213 			if (payload & BIT(EV_REMOTE_ACCESS))
214 				decoder->record.type |= ARM_SPE_REMOTE_ACCESS;
215 
216 			if (payload & BIT(EV_MISPRED))
217 				decoder->record.type |= ARM_SPE_BRANCH_MISS;
218 
219 			break;
220 		case ARM_SPE_DATA_SOURCE:
221 			break;
222 		case ARM_SPE_BAD:
223 			break;
224 		case ARM_SPE_PAD:
225 			break;
226 		default:
227 			pr_err("Get packet error!\n");
228 			return -1;
229 		}
230 	}
231 
232 	return 0;
233 }
234 
235 int arm_spe_decode(struct arm_spe_decoder *decoder)
236 {
237 	return arm_spe_read_record(decoder);
238 }
239