1 /**
2 * Copyright (C) ARM Limited 2010-2012. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 */
9 #include "gator.h"
11 // gator_events_perf_pmu.c is used if perf is supported
12 #if GATOR_NO_PERF_SUPPORT
14 static const char *pmnc_name;
16 /*
17 * Per-CPU PMCR
18 */
19 #define PMCR_E (1 << 0) /* Enable */
20 #define PMCR_P (1 << 1) /* Count reset */
21 #define PMCR_C (1 << 2) /* Cycle counter reset */
22 #define PMCR_OFL_PMN0 (1 << 8) /* Count reg 0 overflow */
23 #define PMCR_OFL_PMN1 (1 << 9) /* Count reg 1 overflow */
24 #define PMCR_OFL_CCNT (1 << 10) /* Cycle counter overflow */
26 #define PMN0 0
27 #define PMN1 1
28 #define CCNT 2
29 #define CNTMAX (CCNT+1)
31 static int pmnc_counters = 0;
32 static unsigned long pmnc_enabled[CNTMAX];
33 static unsigned long pmnc_event[CNTMAX];
34 static unsigned long pmnc_key[CNTMAX];
36 static DEFINE_PER_CPU(int[CNTMAX * 2], perfCnt);
38 static inline void armv6_pmnc_write(u32 val)
39 {
40 /* upper 4bits and 7, 11 are write-as-0 */
41 val &= 0x0ffff77f;
42 asm volatile("mcr p15, 0, %0, c15, c12, 0" : : "r" (val));
43 }
45 static inline u32 armv6_pmnc_read(void)
46 {
47 u32 val;
48 asm volatile("mrc p15, 0, %0, c15, c12, 0" : "=r" (val));
49 return val;
50 }
52 static void armv6_pmnc_reset_counter(unsigned int cnt)
53 {
54 u32 val = 0;
55 switch (cnt) {
56 case CCNT:
57 asm volatile("mcr p15, 0, %0, c15, c12, 1" : : "r" (val));
58 break;
59 case PMN0:
60 asm volatile("mcr p15, 0, %0, c15, c12, 2" : : "r" (val));
61 break;
62 case PMN1:
63 asm volatile("mcr p15, 0, %0, c15, c12, 3" : : "r" (val));
64 break;
65 }
66 }
68 int gator_events_armv6_create_files(struct super_block *sb, struct dentry *root)
69 {
70 struct dentry *dir;
71 int i;
73 pmnc_counters = 3;
75 for (i = PMN0; i <= CCNT; i++) {
76 char buf[40];
77 if (i == CCNT) {
78 snprintf(buf, sizeof buf, "ARM_%s_ccnt", pmnc_name);
79 } else {
80 snprintf(buf, sizeof buf, "ARM_%s_cnt%d", pmnc_name, i);
81 }
82 dir = gatorfs_mkdir(sb, root, buf);
83 if (!dir) {
84 return -1;
85 }
86 gatorfs_create_ulong(sb, dir, "enabled", &pmnc_enabled[i]);
87 gatorfs_create_ro_ulong(sb, dir, "key", &pmnc_key[i]);
88 if (i != CCNT) {
89 gatorfs_create_ulong(sb, dir, "event", &pmnc_event[i]);
90 }
91 }
93 return 0;
94 }
96 static int gator_events_armv6_online(int** buffer)
97 {
98 unsigned int cnt, len = 0, cpu = smp_processor_id();
99 u32 pmnc;
101 if (armv6_pmnc_read() & PMCR_E) {
102 armv6_pmnc_write(armv6_pmnc_read() & ~PMCR_E);
103 }
105 /* initialize PMNC, reset overflow, D bit, C bit and P bit. */
106 armv6_pmnc_write(PMCR_OFL_PMN0 | PMCR_OFL_PMN1 | PMCR_OFL_CCNT |
107 PMCR_C | PMCR_P);
109 /* configure control register */
110 for (pmnc = 0, cnt = PMN0; cnt <= CCNT; cnt++) {
111 unsigned long event;
113 if (!pmnc_enabled[cnt])
114 continue;
116 event = pmnc_event[cnt] & 255;
118 // Set event (if destined for PMNx counters)
119 if (cnt == PMN0) {
120 pmnc |= event << 20;
121 } else if (cnt == PMN1) {
122 pmnc |= event << 12;
123 }
125 // Reset counter
126 armv6_pmnc_reset_counter(cnt);
127 }
128 armv6_pmnc_write(pmnc | PMCR_E);
130 // return zero values, no need to read as the counters were just reset
131 for (cnt = PMN0; cnt <= CCNT; cnt++) {
132 if (pmnc_enabled[cnt]) {
133 per_cpu(perfCnt, cpu)[len++] = pmnc_key[cnt];
134 per_cpu(perfCnt, cpu)[len++] = 0;
135 }
136 }
138 if (buffer)
139 *buffer = per_cpu(perfCnt, cpu);
141 return len;
142 }
144 static int gator_events_armv6_offline(int** buffer)
145 {
146 unsigned int cnt;
148 armv6_pmnc_write(armv6_pmnc_read() & ~PMCR_E);
149 for (cnt = PMN0; cnt <= CCNT; cnt++) {
150 armv6_pmnc_reset_counter(cnt);
151 }
153 return 0;
154 }
156 static void gator_events_armv6_stop(void)
157 {
158 unsigned int cnt;
160 for (cnt = PMN0; cnt <= CCNT; cnt++) {
161 pmnc_enabled[cnt] = 0;
162 pmnc_event[cnt] = 0;
163 }
164 }
166 static int gator_events_armv6_read(int **buffer)
167 {
168 int cnt, len = 0;
169 int cpu = smp_processor_id();
171 // a context switch may occur before the online hotplug event, thus need to check that the pmu is enabled
172 if (!(armv6_pmnc_read() & PMCR_E)) {
173 return 0;
174 }
176 for (cnt = PMN0; cnt <= CCNT; cnt++) {
177 if (pmnc_enabled[cnt]) {
178 u32 value = 0;
179 switch (cnt) {
180 case CCNT:
181 asm volatile("mrc p15, 0, %0, c15, c12, 1" : "=r" (value));
182 break;
183 case PMN0:
184 asm volatile("mrc p15, 0, %0, c15, c12, 2" : "=r" (value));
185 break;
186 case PMN1:
187 asm volatile("mrc p15, 0, %0, c15, c12, 3" : "=r" (value));
188 break;
189 }
190 armv6_pmnc_reset_counter(cnt);
192 per_cpu(perfCnt, cpu)[len++] = pmnc_key[cnt];
193 per_cpu(perfCnt, cpu)[len++] = value;
194 }
195 }
197 if (buffer)
198 *buffer = per_cpu(perfCnt, cpu);
200 return len;
201 }
203 static struct gator_interface gator_events_armv6_interface = {
204 .create_files = gator_events_armv6_create_files,
205 .stop = gator_events_armv6_stop,
206 .online = gator_events_armv6_online,
207 .offline = gator_events_armv6_offline,
208 .read = gator_events_armv6_read,
209 };
211 int gator_events_armv6_init(void)
212 {
213 unsigned int cnt;
215 switch (gator_cpuid()) {
216 case ARM1136:
217 case ARM1156:
218 case ARM1176:
219 pmnc_name = "ARM11";
220 break;
221 case ARM11MPCORE:
222 pmnc_name = "ARM11MPCore";
223 break;
224 default:
225 return -1;
226 }
228 for (cnt = PMN0; cnt <= CCNT; cnt++) {
229 pmnc_enabled[cnt] = 0;
230 pmnc_event[cnt] = 0;
231 pmnc_key[cnt] = gator_events_get_key();
232 }
234 return gator_events_install(&gator_events_armv6_interface);
235 }
237 gator_events_init(gator_events_armv6_init);
239 #else
240 int gator_events_armv6_init(void)
241 {
242 return -1;
243 }
244 #endif