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/compiler.h>
16 #include <linux/zalloc.h>
17 
18 #include "../auxtrace.h"
19 #include "../debug.h"
20 #include "../util.h"
21 
22 #include "arm-spe-decoder.h"
23 
24 #ifndef BIT
25 #define BIT(n)		(1UL << (n))
26 #endif
27 
28 static u64 arm_spe_calc_ip(int index, u64 payload)
29 {
30 	u8 *addr = (u8 *)&payload;
31 	int ns, el;
32 
33 	/* Instruction virtual address or Branch target address */
34 	if (index == SPE_ADDR_PKT_HDR_INDEX_INS ||
35 	    index == SPE_ADDR_PKT_HDR_INDEX_BRANCH) {
36 		ns = addr[7] & SPE_ADDR_PKT_NS;
37 		el = (addr[7] & SPE_ADDR_PKT_EL_MASK) >> SPE_ADDR_PKT_EL_OFFSET;
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 			addr[7] = 0xff;
42 		/* Clean highest byte for other cases */
43 		else
44 			addr[7] = 0x0;
45 
46 	/* Data access virtual address */
47 	} else if (index == SPE_ADDR_PKT_HDR_INDEX_DATA_VIRT) {
48 
49 		/* Fill highest byte if bits [48..55] is 0xff */
50 		if (addr[6] == 0xff)
51 			addr[7] = 0xff;
52 		/* Otherwise, cleanup tags */
53 		else
54 			addr[7] = 0x0;
55 
56 	/* Data access physical address */
57 	} else if (index == SPE_ADDR_PKT_HDR_INDEX_DATA_PHYS) {
58 		/* Cleanup byte 7 */
59 		addr[7] = 0x0;
60 	} else {
61 		pr_err("unsupported address packet index: 0x%x\n", index);
62 	}
63 
64 	return payload;
65 }
66 
67 struct arm_spe_decoder *arm_spe_decoder_new(struct arm_spe_params *params)
68 {
69 	struct arm_spe_decoder *decoder;
70 
71 	if (!params->get_trace)
72 		return NULL;
73 
74 	decoder = zalloc(sizeof(struct arm_spe_decoder));
75 	if (!decoder)
76 		return NULL;
77 
78 	decoder->get_trace = params->get_trace;
79 	decoder->data = params->data;
80 
81 	return decoder;
82 }
83 
84 void arm_spe_decoder_free(struct arm_spe_decoder *decoder)
85 {
86 	free(decoder);
87 }
88 
89 static int arm_spe_get_data(struct arm_spe_decoder *decoder)
90 {
91 	struct arm_spe_buffer buffer = { .buf = 0, };
92 	int ret;
93 
94 	pr_debug("Getting more data\n");
95 	ret = decoder->get_trace(&buffer, decoder->data);
96 	if (ret < 0)
97 		return ret;
98 
99 	decoder->buf = buffer.buf;
100 	decoder->len = buffer.len;
101 
102 	if (!decoder->len)
103 		pr_debug("No more data\n");
104 
105 	return decoder->len;
106 }
107 
108 static int arm_spe_get_next_packet(struct arm_spe_decoder *decoder)
109 {
110 	int ret;
111 
112 	do {
113 		if (!decoder->len) {
114 			ret = arm_spe_get_data(decoder);
115 
116 			/* Failed to read out trace data */
117 			if (ret <= 0)
118 				return ret;
119 		}
120 
121 		ret = arm_spe_get_packet(decoder->buf, decoder->len,
122 					 &decoder->packet);
123 		if (ret <= 0) {
124 			/* Move forward for 1 byte */
125 			decoder->buf += 1;
126 			decoder->len -= 1;
127 			return -EBADMSG;
128 		}
129 
130 		decoder->buf += ret;
131 		decoder->len -= ret;
132 	} while (decoder->packet.type == ARM_SPE_PAD);
133 
134 	return 1;
135 }
136 
137 static int arm_spe_read_record(struct arm_spe_decoder *decoder)
138 {
139 	int err;
140 	int idx;
141 	u64 payload, ip;
142 
143 	memset(&decoder->record, 0x0, sizeof(decoder->record));
144 
145 	while (1) {
146 		err = arm_spe_get_next_packet(decoder);
147 		if (err <= 0)
148 			return err;
149 
150 		idx = decoder->packet.index;
151 		payload = decoder->packet.payload;
152 
153 		switch (decoder->packet.type) {
154 		case ARM_SPE_TIMESTAMP:
155 			decoder->record.timestamp = payload;
156 			return 1;
157 		case ARM_SPE_END:
158 			return 1;
159 		case ARM_SPE_ADDRESS:
160 			ip = arm_spe_calc_ip(idx, payload);
161 			if (idx == SPE_ADDR_PKT_HDR_INDEX_INS)
162 				decoder->record.from_ip = ip;
163 			else if (idx == SPE_ADDR_PKT_HDR_INDEX_BRANCH)
164 				decoder->record.to_ip = ip;
165 			break;
166 		case ARM_SPE_COUNTER:
167 			break;
168 		case ARM_SPE_CONTEXT:
169 			break;
170 		case ARM_SPE_OP_TYPE:
171 			break;
172 		case ARM_SPE_EVENTS:
173 			if (payload & BIT(EV_L1D_REFILL))
174 				decoder->record.type |= ARM_SPE_L1D_MISS;
175 
176 			if (payload & BIT(EV_L1D_ACCESS))
177 				decoder->record.type |= ARM_SPE_L1D_ACCESS;
178 
179 			if (payload & BIT(EV_TLB_WALK))
180 				decoder->record.type |= ARM_SPE_TLB_MISS;
181 
182 			if (payload & BIT(EV_TLB_ACCESS))
183 				decoder->record.type |= ARM_SPE_TLB_ACCESS;
184 
185 			if ((idx == 1 || idx == 2 || idx == 3) &&
186 			    (payload & BIT(EV_LLC_MISS)))
187 				decoder->record.type |= ARM_SPE_LLC_MISS;
188 
189 			if ((idx == 1 || idx == 2 || idx == 3) &&
190 			    (payload & BIT(EV_LLC_ACCESS)))
191 				decoder->record.type |= ARM_SPE_LLC_ACCESS;
192 
193 			if ((idx == 1 || idx == 2 || idx == 3) &&
194 			    (payload & BIT(EV_REMOTE_ACCESS)))
195 				decoder->record.type |= ARM_SPE_REMOTE_ACCESS;
196 
197 			if (payload & BIT(EV_MISPRED))
198 				decoder->record.type |= ARM_SPE_BRANCH_MISS;
199 
200 			break;
201 		case ARM_SPE_DATA_SOURCE:
202 			break;
203 		case ARM_SPE_BAD:
204 			break;
205 		case ARM_SPE_PAD:
206 			break;
207 		default:
208 			pr_err("Get packet error!\n");
209 			return -1;
210 		}
211 	}
212 
213 	return 0;
214 }
215 
216 int arm_spe_decode(struct arm_spe_decoder *decoder)
217 {
218 	return arm_spe_read_record(decoder);
219 }
220