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
25static 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
81struct 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
98void arm_spe_decoder_free(struct arm_spe_decoder *decoder)
99{
100	free(decoder);
101}
102
103static 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
122static 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
151static 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
264int arm_spe_decode(struct arm_spe_decoder *decoder)
265{
266	return arm_spe_read_record(decoder);
267}
268