1 /**
2 * Copyright (C) ARM Limited 2010-2011. 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 #define ARM1136 0xb36
12 #define ARM1156 0xb56
13 #define ARM1176 0xb76
15 static const char *pmnc_name;
17 /*
18 * Per-CPU PMCR
19 */
20 #define PMCR_E (1 << 0) /* Enable */
21 #define PMCR_P (1 << 1) /* Count reset */
22 #define PMCR_C (1 << 2) /* Cycle counter reset */
23 #define PMCR_OFL_PMN0 (1 << 8) /* Count reg 0 overflow */
24 #define PMCR_OFL_PMN1 (1 << 9) /* Count reg 1 overflow */
25 #define PMCR_OFL_CCNT (1 << 10) /* Cycle counter overflow */
27 #define PMN0 0
28 #define PMN1 1
29 #define CCNT 2
30 #define CNTMAX (CCNT+1)
32 static int pmnc_count = 0;
33 static unsigned long pmnc_enabled[CNTMAX];
34 static unsigned long pmnc_event[CNTMAX];
35 static unsigned long pmnc_key[CNTMAX];
37 static DEFINE_PER_CPU(int[CNTMAX], perfPrev);
38 static DEFINE_PER_CPU(int[CNTMAX * 2], perfCnt);
40 static inline void armv6_pmnc_write(u32 val)
41 {
42 /* upper 4bits and 7, 11 are write-as-0 */
43 val &= 0x0ffff77f;
44 asm volatile("mcr p15, 0, %0, c15, c12, 0" : : "r" (val));
45 }
47 static inline u32 armv6_pmnc_read(void)
48 {
49 u32 val;
50 asm volatile("mrc p15, 0, %0, c15, c12, 0" : "=r" (val));
51 return val;
52 }
54 static void armv6_pmnc_reset_counter(unsigned int cnt)
55 {
56 u32 val = 0;
57 switch (cnt) {
58 case CCNT:
59 asm volatile("mcr p15, 0, %0, c15, c12, 1" : : "r" (val));
60 break;
61 case PMN0:
62 asm volatile("mcr p15, 0, %0, c15, c12, 2" : : "r" (val));
63 break;
64 case PMN1:
65 asm volatile("mcr p15, 0, %0, c15, c12, 3" : : "r" (val));
66 break;
67 }
68 }
70 int gator_events_armv6_create_files(struct super_block *sb, struct dentry *root)
71 {
72 struct dentry *dir;
73 int i;
75 pmnc_count = 3;
77 for (i = PMN0; i <= CCNT; i++) {
78 char buf[40];
79 if (i == CCNT) {
80 snprintf(buf, sizeof buf, "ARM_%s_ccnt", pmnc_name);
81 } else {
82 snprintf(buf, sizeof buf, "ARM_%s_cnt%d", pmnc_name, i);
83 }
84 dir = gatorfs_mkdir(sb, root, buf);
85 if (!dir) {
86 return -1;
87 }
88 gatorfs_create_ulong(sb, dir, "enabled", &pmnc_enabled[i]);
89 if (i != CCNT) {
90 gatorfs_create_ulong(sb, dir, "event", &pmnc_event[i]);
91 }
92 gatorfs_create_ro_ulong(sb, dir, "key", &pmnc_key[i]);
93 }
95 return 0;
96 }
98 static void gator_events_armv6_online(void)
99 {
100 unsigned int cnt;
101 u32 pmnc;
103 if (armv6_pmnc_read() & PMCR_E) {
104 armv6_pmnc_write(armv6_pmnc_read() & ~PMCR_E);
105 }
107 /* initialize PMNC, reset overflow, D bit, C bit and P bit. */
108 armv6_pmnc_write(PMCR_OFL_PMN0 | PMCR_OFL_PMN1 | PMCR_OFL_CCNT |
109 PMCR_C | PMCR_P);
111 /* configure control register */
112 for (pmnc = 0, cnt = PMN0; cnt <= CCNT; cnt++) {
113 unsigned long event;
115 per_cpu(perfPrev, smp_processor_id())[cnt] = 0;
117 if (!pmnc_enabled[cnt])
118 continue;
120 event = pmnc_event[cnt] & 255;
122 /*
123 * Set event (if destined for PMNx counters)
124 */
125 if (cnt == PMN0) {
126 pmnc |= event << 20;
127 } else if (cnt == PMN1) {
128 pmnc |= event << 12;
129 }
131 /*
132 * Reset counter
133 */
134 armv6_pmnc_reset_counter(cnt);
135 }
136 armv6_pmnc_write(pmnc | PMCR_E);
137 }
139 static void gator_events_armv6_offline(void)
140 {
141 unsigned int cnt;
143 armv6_pmnc_write(armv6_pmnc_read() & ~PMCR_E);
144 for (cnt = PMN0; cnt <= CCNT; cnt++) {
145 armv6_pmnc_reset_counter(cnt);
146 }
147 }
149 static void gator_events_armv6_stop(void)
150 {
151 unsigned int cnt;
153 for (cnt = PMN0; cnt <= CCNT; cnt++) {
154 pmnc_enabled[cnt] = 0;
155 pmnc_event[cnt] = 0;
156 }
157 }
159 static int gator_events_armv6_read(int **buffer)
160 {
161 int cnt, len = 0;
162 int cpu = smp_processor_id();
164 for (cnt = PMN0; cnt <= CCNT; cnt++) {
165 if (pmnc_enabled[cnt]) {
166 u32 value = 0;
167 switch (cnt) {
168 case CCNT:
169 asm volatile("mrc p15, 0, %0, c15, c12, 1" : "=r" (value));
170 break;
171 case PMN0:
172 asm volatile("mrc p15, 0, %0, c15, c12, 2" : "=r" (value));
173 break;
174 case PMN1:
175 asm volatile("mrc p15, 0, %0, c15, c12, 3" : "=r" (value));
176 break;
177 }
178 armv6_pmnc_reset_counter(cnt);
179 if (value != per_cpu(perfPrev, cpu)[cnt]) {
180 per_cpu(perfPrev, cpu)[cnt] = value;
181 per_cpu(perfCnt, cpu)[len++] = pmnc_key[cnt];
182 per_cpu(perfCnt, cpu)[len++] = value;
183 }
184 }
185 }
187 // update or discard
188 if (buffer)
189 *buffer = per_cpu(perfCnt, cpu);
191 return len;
192 }
194 static struct gator_interface gator_events_armv6_interface = {
195 .create_files = gator_events_armv6_create_files,
196 .stop = gator_events_armv6_stop,
197 .online = gator_events_armv6_online,
198 .offline = gator_events_armv6_offline,
199 .read = gator_events_armv6_read,
200 };
202 int gator_events_armv6_init(void)
203 {
204 unsigned int cnt;
206 switch (gator_cpuid()) {
207 case ARM1136:
208 case ARM1156:
209 case ARM1176:
210 pmnc_name = "ARM11";
211 break;
212 default:
213 return -1;
214 }
216 for (cnt = PMN0; cnt <= CCNT; cnt++) {
217 pmnc_enabled[cnt] = 0;
218 pmnc_event[cnt] = 0;
219 pmnc_key[cnt] = gator_events_get_key();
220 }
222 return gator_events_install(&gator_events_armv6_interface);
223 }
224 gator_events_init(gator_events_armv6_init);