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#include <linux/init.h> 13#include <linux/oprofile.h> 14#include <linux/interrupt.h> 15 16#include <loongson.h> /* LOONGSON2_PERFCNT_IRQ */ 17#include "op_impl.h" 18 19#define LOONGSON2_CPU_TYPE "mips/loongson2" 20 21#define LOONGSON2_PERFCNT_OVERFLOW (1ULL << 31) 22 23#define LOONGSON2_PERFCTRL_EXL (1UL << 0) 24#define LOONGSON2_PERFCTRL_KERNEL (1UL << 1) 25#define LOONGSON2_PERFCTRL_SUPERVISOR (1UL << 2) 26#define LOONGSON2_PERFCTRL_USER (1UL << 3) 27#define LOONGSON2_PERFCTRL_ENABLE (1UL << 4) 28#define LOONGSON2_PERFCTRL_EVENT(idx, event) \ 29 (((event) & 0x0f) << ((idx) ? 9 : 5)) 30 31#define read_c0_perfctrl() __read_64bit_c0_register($24, 0) 32#define write_c0_perfctrl(val) __write_64bit_c0_register($24, 0, val) 33#define read_c0_perfcnt() __read_64bit_c0_register($25, 0) 34#define write_c0_perfcnt(val) __write_64bit_c0_register($25, 0, val) 35 36static struct loongson2_register_config { 37 unsigned int ctrl; 38 unsigned long long reset_counter1; 39 unsigned long long reset_counter2; 40 int cnt1_enabled, cnt2_enabled; 41} reg; 42 43static char *oprofid = "LoongsonPerf"; 44static irqreturn_t loongson2_perfcount_handler(int irq, void *dev_id); 45 46static void reset_counters(void *arg) 47{ 48 write_c0_perfctrl(0); 49 write_c0_perfcnt(0); 50} 51 52static void loongson2_reg_setup(struct op_counter_config *cfg) 53{ 54 unsigned int ctrl = 0; 55 56 reg.reset_counter1 = 0; 57 reg.reset_counter2 = 0; 58 59 /* 60 * Compute the performance counter ctrl word. 61 * For now, count kernel and user mode. 62 */ 63 if (cfg[0].enabled) { 64 ctrl |= LOONGSON2_PERFCTRL_EVENT(0, cfg[0].event); 65 reg.reset_counter1 = 0x80000000ULL - cfg[0].count; 66 } 67 68 if (cfg[1].enabled) { 69 ctrl |= LOONGSON2_PERFCTRL_EVENT(1, cfg[1].event); 70 reg.reset_counter2 = 0x80000000ULL - cfg[1].count; 71 } 72 73 if (cfg[0].enabled || cfg[1].enabled) { 74 ctrl |= LOONGSON2_PERFCTRL_EXL | LOONGSON2_PERFCTRL_ENABLE; 75 if (cfg[0].kernel || cfg[1].kernel) 76 ctrl |= LOONGSON2_PERFCTRL_KERNEL; 77 if (cfg[0].user || cfg[1].user) 78 ctrl |= LOONGSON2_PERFCTRL_USER; 79 } 80 81 reg.ctrl = ctrl; 82 83 reg.cnt1_enabled = cfg[0].enabled; 84 reg.cnt2_enabled = cfg[1].enabled; 85} 86 87static void loongson2_cpu_setup(void *args) 88{ 89 write_c0_perfcnt((reg.reset_counter2 << 32) | reg.reset_counter1); 90} 91 92static void loongson2_cpu_start(void *args) 93{ 94 /* Start all counters on current CPU */ 95 if (reg.cnt1_enabled || reg.cnt2_enabled) 96 write_c0_perfctrl(reg.ctrl); 97} 98 99static void loongson2_cpu_stop(void *args) 100{ 101 /* Stop all counters on current CPU */ 102 write_c0_perfctrl(0); 103 memset(®, 0, sizeof(reg)); 104} 105 106static irqreturn_t loongson2_perfcount_handler(int irq, void *dev_id) 107{ 108 uint64_t counter, counter1, counter2; 109 struct pt_regs *regs = get_irq_regs(); 110 int enabled; 111 112 /* Check whether the irq belongs to me */ 113 enabled = read_c0_perfctrl() & LOONGSON2_PERFCTRL_ENABLE; 114 if (!enabled) 115 return IRQ_NONE; 116 enabled = reg.cnt1_enabled | reg.cnt2_enabled; 117 if (!enabled) 118 return IRQ_NONE; 119 120 counter = read_c0_perfcnt(); 121 counter1 = counter & 0xffffffff; 122 counter2 = counter >> 32; 123 124 if (counter1 & LOONGSON2_PERFCNT_OVERFLOW) { 125 if (reg.cnt1_enabled) 126 oprofile_add_sample(regs, 0); 127 counter1 = reg.reset_counter1; 128 } 129 if (counter2 & LOONGSON2_PERFCNT_OVERFLOW) { 130 if (reg.cnt2_enabled) 131 oprofile_add_sample(regs, 1); 132 counter2 = reg.reset_counter2; 133 } 134 135 write_c0_perfcnt((counter2 << 32) | counter1); 136 137 return IRQ_HANDLED; 138} 139 140static int __init loongson2_init(void) 141{ 142 return request_irq(LOONGSON2_PERFCNT_IRQ, loongson2_perfcount_handler, 143 IRQF_SHARED, "Perfcounter", oprofid); 144} 145 146static void loongson2_exit(void) 147{ 148 reset_counters(NULL); 149 free_irq(LOONGSON2_PERFCNT_IRQ, oprofid); 150} 151 152struct op_mips_model op_model_loongson2_ops = { 153 .reg_setup = loongson2_reg_setup, 154 .cpu_setup = loongson2_cpu_setup, 155 .init = loongson2_init, 156 .exit = loongson2_exit, 157 .cpu_start = loongson2_cpu_start, 158 .cpu_stop = loongson2_cpu_stop, 159 .cpu_type = LOONGSON2_CPU_TYPE, 160 .num_counters = 2 161}; 162