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 000000000000..655cb8dec340
--- /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_enalbed, cnt2_enalbed;
+} 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_enalbed = cfg[0].enabled;
+        reg.cnt2_enalbed = 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_enalbed || reg.cnt2_enalbed)
+                write_c0_perfctrl(reg.ctrl);
+}
+
+static void loongson2_cpu_stop(void *args)
+{
+        /* Stop all counters on current CPU */
+        write_c0_perfctrl(0);
+        memset(&reg, 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_enalbed | reg.cnt2_enalbed;
+        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_enalbed)
+                        oprofile_add_sample(regs, 0);
+                counter1 = reg.reset_counter1;
+        }
+        if (counter2 & LOONGSON2_PERFCNT_OVERFLOW) {
+                if (reg.cnt2_enalbed)
+                        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
+};