diff options
Diffstat (limited to 'arch/mips/oprofile/op_model_loongson2.c')
| -rw-r--r-- | arch/mips/oprofile/op_model_loongson2.c | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/arch/mips/oprofile/op_model_loongson2.c b/arch/mips/oprofile/op_model_loongson2.c new file mode 100644 index 00000000000..deed1d5d498 --- /dev/null +++ b/arch/mips/oprofile/op_model_loongson2.c @@ -0,0 +1,177 @@ +/* + * Loongson2 performance counter driver for oprofile + * + * Copyright (C) 2009 Lemote Inc. & Insititute of Computing Technology + * Author: Yanhua <yanh@lemote.com> + * Author: Wu Zhangjin <wuzj@lemote.com> + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + */ +#include <linux/init.h> +#include <linux/oprofile.h> +#include <linux/interrupt.h> + +#include <loongson.h> /* LOONGSON2_PERFCNT_IRQ */ +#include "op_impl.h" + +/* + * a patch should be sent to oprofile with the loongson-specific support. + * otherwise, the oprofile tool will not recognize this and complain about + * "cpu_type 'unset' is not valid". + */ +#define LOONGSON2_CPU_TYPE "mips/godson2" + +#define LOONGSON2_COUNTER1_EVENT(event) ((event & 0x0f) << 5) +#define LOONGSON2_COUNTER2_EVENT(event) ((event & 0x0f) << 9) + +#define LOONGSON2_PERFCNT_EXL (1UL << 0) +#define LOONGSON2_PERFCNT_KERNEL (1UL << 1) +#define LOONGSON2_PERFCNT_SUPERVISOR (1UL << 2) +#define LOONGSON2_PERFCNT_USER (1UL << 3) +#define LOONGSON2_PERFCNT_INT_EN (1UL << 4) +#define LOONGSON2_PERFCNT_OVERFLOW (1ULL << 31) + +/* Loongson2 performance counter register */ +#define read_c0_perfctrl() __read_64bit_c0_register($24, 0) +#define write_c0_perfctrl(val) __write_64bit_c0_register($24, 0, val) +#define read_c0_perfcnt() __read_64bit_c0_register($25, 0) +#define write_c0_perfcnt(val) __write_64bit_c0_register($25, 0, val) + +static struct loongson2_register_config { + unsigned int ctrl; + unsigned long long reset_counter1; + unsigned long long reset_counter2; + int cnt1_enabled, cnt2_enabled; +} reg; + +DEFINE_SPINLOCK(sample_lock); + +static char *oprofid = "LoongsonPerf"; +static irqreturn_t loongson2_perfcount_handler(int irq, void *dev_id); +/* Compute all of the registers in preparation for enabling profiling. */ + +static void loongson2_reg_setup(struct op_counter_config *cfg) +{ + unsigned int ctrl = 0; + + reg.reset_counter1 = 0; + reg.reset_counter2 = 0; + /* Compute the performance counter ctrl word. */ + /* For now count kernel and user mode */ + if (cfg[0].enabled) { + ctrl |= LOONGSON2_COUNTER1_EVENT(cfg[0].event); + reg.reset_counter1 = 0x80000000ULL - cfg[0].count; + } + + if (cfg[1].enabled) { + ctrl |= LOONGSON2_COUNTER2_EVENT(cfg[1].event); + reg.reset_counter2 = (0x80000000ULL - cfg[1].count); + } + + if (cfg[0].enabled || cfg[1].enabled) { + ctrl |= LOONGSON2_PERFCNT_EXL | LOONGSON2_PERFCNT_INT_EN; + if (cfg[0].kernel || cfg[1].kernel) + ctrl |= LOONGSON2_PERFCNT_KERNEL; + if (cfg[0].user || cfg[1].user) + ctrl |= LOONGSON2_PERFCNT_USER; + } + + reg.ctrl = ctrl; + + reg.cnt1_enabled = cfg[0].enabled; + reg.cnt2_enabled = cfg[1].enabled; + +} + +/* Program all of the registers in preparation for enabling profiling. */ + +static void loongson2_cpu_setup(void *args) +{ + uint64_t perfcount; + + perfcount = (reg.reset_counter2 << 32) | reg.reset_counter1; + write_c0_perfcnt(perfcount); +} + +static void loongson2_cpu_start(void *args) +{ + /* Start all counters on current CPU */ + if (reg.cnt1_enabled || reg.cnt2_enabled) + write_c0_perfctrl(reg.ctrl); +} + +static void loongson2_cpu_stop(void *args) +{ + /* Stop all counters on current CPU */ + write_c0_perfctrl(0); + memset(®, 0, sizeof(reg)); +} + +static irqreturn_t loongson2_perfcount_handler(int irq, void *dev_id) +{ + uint64_t counter, counter1, counter2; + struct pt_regs *regs = get_irq_regs(); + int enabled; + unsigned long flags; + + /* + * LOONGSON2 defines two 32-bit performance counters. + * To avoid a race updating the registers we need to stop the counters + * while we're messing with + * them ... + */ + + /* Check whether the irq belongs to me */ + enabled = reg.cnt1_enabled | reg.cnt2_enabled; + if (!enabled) + return IRQ_NONE; + + counter = read_c0_perfcnt(); + counter1 = counter & 0xffffffff; + counter2 = counter >> 32; + + spin_lock_irqsave(&sample_lock, flags); + + if (counter1 & LOONGSON2_PERFCNT_OVERFLOW) { + if (reg.cnt1_enabled) + oprofile_add_sample(regs, 0); + counter1 = reg.reset_counter1; + } + if (counter2 & LOONGSON2_PERFCNT_OVERFLOW) { + if (reg.cnt2_enabled) + oprofile_add_sample(regs, 1); + counter2 = reg.reset_counter2; + } + + spin_unlock_irqrestore(&sample_lock, flags); + + write_c0_perfcnt((counter2 << 32) | counter1); + + return IRQ_HANDLED; +} + +static int __init loongson2_init(void) +{ + return request_irq(LOONGSON2_PERFCNT_IRQ, loongson2_perfcount_handler, + IRQF_SHARED, "Perfcounter", oprofid); +} + +static void loongson2_exit(void) +{ + write_c0_perfctrl(0); + free_irq(LOONGSON2_PERFCNT_IRQ, oprofid); +} + +struct op_mips_model op_model_loongson2_ops = { + .reg_setup = loongson2_reg_setup, + .cpu_setup = loongson2_cpu_setup, + .init = loongson2_init, + .exit = loongson2_exit, + .cpu_start = loongson2_cpu_start, + .cpu_stop = loongson2_cpu_stop, + .cpu_type = LOONGSON2_CPU_TYPE, + .num_counters = 2 +}; |