Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6
[linux-2.6.git] / arch / mips / oprofile / op_model_loongson2.c
1 /*
2  * Loongson2 performance counter driver for oprofile
3  *
4  * Copyright (C) 2009 Lemote Inc.
5  * Author: Yanhua <yanh@lemote.com>
6  * Author: Wu Zhangjin <wuzhangjin@gmail.com>
7  *
8  * This file is subject to the terms and conditions of the GNU General Public
9  * License.  See the file "COPYING" in the main directory of this archive
10  * for more details.
11  *
12  */
13 #include <linux/init.h>
14 #include <linux/oprofile.h>
15 #include <linux/interrupt.h>
16
17 #include <loongson.h>                   /* LOONGSON2_PERFCNT_IRQ */
18 #include "op_impl.h"
19
20 /*
21  * a patch should be sent to oprofile with the loongson-specific support.
22  * otherwise, the oprofile tool will not recognize this and complain about
23  * "cpu_type 'unset' is not valid".
24  */
25 #define LOONGSON2_CPU_TYPE      "mips/loongson2"
26
27 #define LOONGSON2_COUNTER1_EVENT(event) ((event & 0x0f) << 5)
28 #define LOONGSON2_COUNTER2_EVENT(event) ((event & 0x0f) << 9)
29
30 #define LOONGSON2_PERFCNT_EXL                   (1UL    <<  0)
31 #define LOONGSON2_PERFCNT_KERNEL                (1UL    <<  1)
32 #define LOONGSON2_PERFCNT_SUPERVISOR    (1UL    <<  2)
33 #define LOONGSON2_PERFCNT_USER                  (1UL    <<  3)
34 #define LOONGSON2_PERFCNT_INT_EN                (1UL    <<  4)
35 #define LOONGSON2_PERFCNT_OVERFLOW              (1ULL   << 31)
36
37 /* Loongson2 performance counter register */
38 #define read_c0_perfctrl() __read_64bit_c0_register($24, 0)
39 #define write_c0_perfctrl(val) __write_64bit_c0_register($24, 0, val)
40 #define read_c0_perfcnt() __read_64bit_c0_register($25, 0)
41 #define write_c0_perfcnt(val) __write_64bit_c0_register($25, 0, val)
42
43 static struct loongson2_register_config {
44         unsigned int ctrl;
45         unsigned long long reset_counter1;
46         unsigned long long reset_counter2;
47         int cnt1_enabled, cnt2_enabled;
48 } reg;
49
50 static char *oprofid = "LoongsonPerf";
51 static irqreturn_t loongson2_perfcount_handler(int irq, void *dev_id);
52 /* Compute all of the registers in preparation for enabling profiling.  */
53
54 static void loongson2_reg_setup(struct op_counter_config *cfg)
55 {
56         unsigned int ctrl = 0;
57
58         reg.reset_counter1 = 0;
59         reg.reset_counter2 = 0;
60         /* Compute the performance counter ctrl word.  */
61         /* For now count kernel and user mode */
62         if (cfg[0].enabled) {
63                 ctrl |= LOONGSON2_COUNTER1_EVENT(cfg[0].event);
64                 reg.reset_counter1 = 0x80000000ULL - cfg[0].count;
65         }
66
67         if (cfg[1].enabled) {
68                 ctrl |= LOONGSON2_COUNTER2_EVENT(cfg[1].event);
69                 reg.reset_counter2 = (0x80000000ULL - cfg[1].count);
70         }
71
72         if (cfg[0].enabled || cfg[1].enabled) {
73                 ctrl |= LOONGSON2_PERFCNT_EXL | LOONGSON2_PERFCNT_INT_EN;
74                 if (cfg[0].kernel || cfg[1].kernel)
75                         ctrl |= LOONGSON2_PERFCNT_KERNEL;
76                 if (cfg[0].user || cfg[1].user)
77                         ctrl |= LOONGSON2_PERFCNT_USER;
78         }
79
80         reg.ctrl = ctrl;
81
82         reg.cnt1_enabled = cfg[0].enabled;
83         reg.cnt2_enabled = cfg[1].enabled;
84
85 }
86
87 /* Program all of the registers in preparation for enabling profiling.  */
88
89 static void loongson2_cpu_setup(void *args)
90 {
91         uint64_t perfcount;
92
93         perfcount = (reg.reset_counter2 << 32) | reg.reset_counter1;
94         write_c0_perfcnt(perfcount);
95 }
96
97 static void loongson2_cpu_start(void *args)
98 {
99         /* Start all counters on current CPU */
100         if (reg.cnt1_enabled || reg.cnt2_enabled)
101                 write_c0_perfctrl(reg.ctrl);
102 }
103
104 static void loongson2_cpu_stop(void *args)
105 {
106         /* Stop all counters on current CPU */
107         write_c0_perfctrl(0);
108         memset(&reg, 0, sizeof(reg));
109 }
110
111 static irqreturn_t loongson2_perfcount_handler(int irq, void *dev_id)
112 {
113         uint64_t counter, counter1, counter2;
114         struct pt_regs *regs = get_irq_regs();
115         int enabled;
116
117         /*
118          * LOONGSON2 defines two 32-bit performance counters.
119          * To avoid a race updating the registers we need to stop the counters
120          * while we're messing with
121          * them ...
122          */
123
124         /* Check whether the irq belongs to me */
125         enabled = read_c0_perfcnt() & LOONGSON2_PERFCNT_INT_EN;
126         if (!enabled)
127                 return IRQ_NONE;
128         enabled = reg.cnt1_enabled | reg.cnt2_enabled;
129         if (!enabled)
130                 return IRQ_NONE;
131
132         counter = read_c0_perfcnt();
133         counter1 = counter & 0xffffffff;
134         counter2 = counter >> 32;
135
136         if (counter1 & LOONGSON2_PERFCNT_OVERFLOW) {
137                 if (reg.cnt1_enabled)
138                         oprofile_add_sample(regs, 0);
139                 counter1 = reg.reset_counter1;
140         }
141         if (counter2 & LOONGSON2_PERFCNT_OVERFLOW) {
142                 if (reg.cnt2_enabled)
143                         oprofile_add_sample(regs, 1);
144                 counter2 = reg.reset_counter2;
145         }
146
147         write_c0_perfcnt((counter2 << 32) | counter1);
148
149         return IRQ_HANDLED;
150 }
151
152 static int __init loongson2_init(void)
153 {
154         return request_irq(LOONGSON2_PERFCNT_IRQ, loongson2_perfcount_handler,
155                            IRQF_SHARED, "Perfcounter", oprofid);
156 }
157
158 static void loongson2_exit(void)
159 {
160         write_c0_perfctrl(0);
161         free_irq(LOONGSON2_PERFCNT_IRQ, oprofid);
162 }
163
164 struct op_mips_model op_model_loongson2_ops = {
165         .reg_setup = loongson2_reg_setup,
166         .cpu_setup = loongson2_cpu_setup,
167         .init = loongson2_init,
168         .exit = loongson2_exit,
169         .cpu_start = loongson2_cpu_start,
170         .cpu_stop = loongson2_cpu_stop,
171         .cpu_type = LOONGSON2_CPU_TYPE,
172         .num_counters = 2
173 };