[PATCH 6/14] lemote: Loongson2 specific OProfile driver

[PATCH 6/14] lemote: Loongson2 specific OProfile driver

[yanhua]

Note: there are some conflicts between performance counters and CPU
count timers, so use a different system timer if you want to use
OProfile on loongson2 systems
---
arch/mips/oprofile/Makefile | 1 +
arch/mips/oprofile/common.c | 5 +
arch/mips/oprofile/op_model_loongson2.c | 190
+++++++++++++++++++++++++++++++
3 files changed, 196 insertions(+), 0 deletions(-)
create mode 100644 arch/mips/oprofile/op_model_loongson2.c

diff --git a/arch/mips/oprofile/Makefile b/arch/mips/oprofile/Makefile
index bf3be6f..d039d6b 100644
--- a/arch/mips/oprofile/Makefile
+++ b/arch/mips/oprofile/Makefile
@@ -15,3 +15,4 @@ oprofile-$(CONFIG_CPU_MIPS64) += op_model_mipsxx.o
oprofile-$(CONFIG_CPU_R10000) += op_model_mipsxx.o
oprofile-$(CONFIG_CPU_SB1) += op_model_mipsxx.o
oprofile-$(CONFIG_CPU_RM9000) += op_model_rm9000.o
+oprofile-$(CONFIG_CPU_LOONGSON2) += op_model_loongson2.o
diff --git a/arch/mips/oprofile/common.c b/arch/mips/oprofile/common.c
index 3bf3354..f0e79e3 100644
--- a/arch/mips/oprofile/common.c
+++ b/arch/mips/oprofile/common.c
@@ -16,6 +16,7 @@

extern struct op_mips_model op_model_mipsxx_ops __attribute__((weak));
extern struct op_mips_model op_model_rm9000_ops __attribute__((weak));
+extern struct op_mips_model op_model_loongson2_ops __attribute__((weak));

static struct op_mips_model *model;

@@ -93,6 +94,10 @@ int __init oprofile_arch_init(struct
oprofile_operations *ops)
case CPU_RM9000:
lmodel = &op_model_rm9000_ops;
break;
+
+ case CPU_LOONGSON2:
+ lmodel = &op_model_loongson2_ops;
+ break;
};

if (!lmodel)
diff --git a/arch/mips/oprofile/op_model_loongson2.c
b/arch/mips/oprofile/op_model_loongson2.c
new file mode 100644
index 0000000..9456c9a
--- /dev/null
+++ b/arch/mips/oprofile/op_model_loongson2.c
@@ -0,0 +1,190 @@
+/*
+ * Loongson2 performance counter driver for oprofile
+ *
+ * Author: Yanhua <yanh@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 <linux/smp.h>
+#include <linux/spinlock.h>
+#include <linux/proc_fs.h>
+#include <asm/uaccess.h>
+
+#include <irq.h>
+#include "op_impl.h"
+
+#define PERF_IRQ (MIPS_CPU_IRQ_BASE + 6 )
+
+#define LOONGSON_COUNTER1_EVENT(event) ((event&0x0f) << 5)
+#define LOONGSON_COUNTER1_SUPERVISOR (1UL << 2)
+#define LOONGSON_COUNTER1_KERNEL (1UL << 1)
+#define LOONGSON_COUNTER1_USER (1UL << 3)
+#define LOONGSON_COUNTER1_ENABLE (1UL << 4)
+#define LOONGSON_COUNTER1_OVERFLOW (1ULL << 31)
+#define LOONGSON_COUNTER1_EXL (1UL << 0)
+
+#define LOONGSON_COUNTER2_EVENT(event) ((event&0x0f) << 9)
+#define LOONGSON_COUNTER2_SUPERVISOR LOONGSON_COUNTER1_SUPERVISOR
+#define LOONGSON_COUNTER2_KERNEL LOONGSON_COUNTER1_KERNEL
+#define LOONGSON_COUNTER2_USER LOONGSON_COUNTER1_USER
+#define LOONGSON_COUNTER2_ENABLE LOONGSON_COUNTER1_ENABLE
+#define LOONGSON_COUNTER2_OVERFLOW (1ULL << 31)
+#define LOONGSON_COUNTER2_EXL (1UL << 0 )
+#define LOONGSON_COUNTER_EXL (1UL << 0)
+
+/* Loongson2 PerfCount performance counter register */
+#define read_c0_perflo() __read_64bit_c0_register($24, 0)
+#define write_c0_perflo(val) __write_64bit_c0_register($24, 0, val)
+#define read_c0_perfhi() __read_64bit_c0_register($25, 0)
+#define write_c0_perfhi(val) __write_64bit_c0_register($25, 0, val)
+
+extern unsigned int loongson2_perfcount_irq;
+
+static struct loongson2_register_config {
+ unsigned int control;
+ unsigned long long reset_counter1;
+ unsigned long long reset_counter2;
+ int ctr1_enable, ctr2_enable;
+} 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 *ctr)
+{
+ unsigned int control = 0;
+
+ reg.reset_counter1 = 0;
+ reg.reset_counter2 = 0;
+ /* Compute the performance counter control word. */
+ /* For now count kernel and user mode */
+ if (ctr[0].enabled){
+ control |= LOONGSON_COUNTER1_EVENT(ctr[0].event) |
+ LOONGSON_COUNTER1_ENABLE;
+ if(ctr[0].kernel)
+ control |= LOONGSON_COUNTER1_KERNEL;
+ if(ctr[0].user)
+ control |= LOONGSON_COUNTER1_USER;
+ reg.reset_counter1 = 0x80000000ULL - ctr[0].count;
+ }
+
+ if (ctr[1].enabled){
+ control |= LOONGSON_COUNTER2_EVENT(ctr[1].event) |
+ LOONGSON_COUNTER2_ENABLE;
+ if(ctr[1].kernel)
+ control |= LOONGSON_COUNTER2_KERNEL;
+ if(ctr[1].user)
+ control |= LOONGSON_COUNTER2_USER;
+ reg.reset_counter2 = (0x80000000ULL- ctr[1].count) ;
+ }
+
+ if(ctr[0].enabled ||ctr[1].enabled)
+ control |= LOONGSON_COUNTER_EXL;
+
+ reg.control = control;
+
+ reg.ctr1_enable = ctr[0].enabled;
+ reg.ctr2_enable = ctr[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_perfhi(perfcount);
+}
+
+static void loongson2_cpu_start(void *args)
+{
+ /* Start all counters on current CPU */
+ if(reg.ctr1_enable || reg.ctr2_enable) {
+ write_c0_perflo(reg.control);
+ }
+}
+
+static void loongson2_cpu_stop(void *args)
+{
+ /* Stop all counters on current CPU */
+ write_c0_perflo(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.ctr1_enable| reg.ctr2_enable;
+ if(!enabled){
+ return IRQ_NONE;
+ }
+
+ counter = read_c0_perfhi();
+ counter1 = counter & 0xffffffff;
+ counter2 = counter >> 32;
+
+ spin_lock_irqsave(&sample_lock, flags);
+
+ if (counter1 & LOONGSON_COUNTER1_OVERFLOW) {
+ if(reg.ctr1_enable)
+ oprofile_add_sample(regs, 0);
+ counter1 = reg.reset_counter1;
+ }
+ if (counter2 & LOONGSON_COUNTER2_OVERFLOW) {
+ if(reg.ctr2_enable)
+ oprofile_add_sample(regs, 1);
+ counter2 = reg.reset_counter2;
+ }
+
+ spin_unlock_irqrestore(&sample_lock, flags);
+
+ write_c0_perfhi((counter2 << 32) | counter1);
+
+ return IRQ_HANDLED;
+}
+
+static int __init loongson2_init(void)
+{
+ return request_irq(PERF_IRQ, loongson2_perfcount_handler,
+ IRQF_SHARED, "Perfcounter", oprofid);
+}
+
+static void loongson2_exit(void)
+{
+ write_c0_perflo(0);
+ free_irq(PERF_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 = "mips/godson2",
+ .num_counters = 2
+};
-- 
1.5.6.5