[AVR32] Oprofile support

This adds the necessary architecture code to run oprofile on AVR32
using the performance counters documented by the AVR32 Architecture
Manual.

Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Acked-by: Philippe Elie <phil.el@wanadoo.fr>

2 files changed, 243 insertions, 0 deletions

diff --git a/arch/avr32/oprofile/Makefile b/arch/avr32/oprofile/Makefile
new file mode 100644
index 000000000000..1fe81c3c1e86
--- /dev/null
+++ b/arch/avr32/oprofile/Makefile
@@ -0,0 +1,8 @@
+obj-$(CONFIG_OPROFILE) += oprofile.o
+
+oprofile-y              := $(addprefix ../../../drivers/oprofile/,      \
+                                oprof.o cpu_buffer.o buffer_sync.o      \
+                                event_buffer.o oprofile_files.o         \
+                                oprofilefs.o oprofile_stats.o           \
+                                timer_int.o)
+oprofile-y              += op_model_avr32.o
diff --git a/arch/avr32/oprofile/op_model_avr32.c b/arch/avr32/oprofile/op_model_avr32.c
new file mode 100644
index 000000000000..e2f876bfc86b
--- /dev/null
+++ b/arch/avr32/oprofile/op_model_avr32.c
@@ -0,0 +1,235 @@
+/*
+ * AVR32 Performance Counter Driver
+ *
+ * Copyright (C) 2005-2007 Atmel Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Author: Ronny Pedersen
+ */
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/oprofile.h>
+#include <linux/sched.h>
+#include <linux/types.h>
+
+#include <asm/intc.h>
+#include <asm/sysreg.h>
+#include <asm/system.h>
+
+#define AVR32_PERFCTR_IRQ_GROUP 0
+#define AVR32_PERFCTR_IRQ_LINE  1
+
+enum { PCCNT, PCNT0, PCNT1, NR_counter };
+
+struct avr32_perf_counter {
+        unsigned long   enabled;
+        unsigned long   event;
+        unsigned long   count;
+        unsigned long   unit_mask;
+        unsigned long   kernel;
+        unsigned long   user;
+
+        u32             ie_mask;
+        u32             flag_mask;
+};
+
+static struct avr32_perf_counter counter[NR_counter] = {
+        {
+                .ie_mask        = SYSREG_BIT(IEC),
+                .flag_mask      = SYSREG_BIT(FC),
+        }, {
+                .ie_mask        = SYSREG_BIT(IE0),
+                .flag_mask      = SYSREG_BIT(F0),
+        }, {
+                .ie_mask        = SYSREG_BIT(IE1),
+                .flag_mask      = SYSREG_BIT(F1),
+        },
+};
+
+static void avr32_perf_counter_reset(void)
+{
+        /* Reset all counter and disable/clear all interrupts */
+        sysreg_write(PCCR, (SYSREG_BIT(PCCR_R)
+                                | SYSREG_BIT(PCCR_C)
+                                | SYSREG_BIT(FC)
+                                | SYSREG_BIT(F0)
+                                | SYSREG_BIT(F1)));
+}
+
+static irqreturn_t avr32_perf_counter_interrupt(int irq, void *dev_id)
+{
+        struct avr32_perf_counter *ctr = dev_id;
+        struct pt_regs *regs;
+        u32 pccr;
+
+        if (likely(!(intc_get_pending(AVR32_PERFCTR_IRQ_GROUP)
+                                        & (1 << AVR32_PERFCTR_IRQ_LINE))))
+                return IRQ_NONE;
+
+        regs = get_irq_regs();
+        pccr = sysreg_read(PCCR);
+
+        /* Clear the interrupt flags we're about to handle */
+        sysreg_write(PCCR, pccr);
+
+        /* PCCNT */
+        if (ctr->enabled && (pccr & ctr->flag_mask)) {
+                sysreg_write(PCCNT, -ctr->count);
+                oprofile_add_sample(regs, PCCNT);
+        }
+        ctr++;
+        /* PCNT0 */
+        if (ctr->enabled && (pccr & ctr->flag_mask)) {
+                sysreg_write(PCNT0, -ctr->count);
+                oprofile_add_sample(regs, PCNT0);
+        }
+        ctr++;
+        /* PCNT1 */
+        if (ctr->enabled && (pccr & ctr->flag_mask)) {
+                sysreg_write(PCNT1, -ctr->count);
+                oprofile_add_sample(regs, PCNT1);
+        }
+
+        return IRQ_HANDLED;
+}
+
+static int avr32_perf_counter_create_files(struct super_block *sb,
+                struct dentry *root)
+{
+        struct dentry *dir;
+        unsigned int i;
+        char filename[4];
+
+        for (i = 0; i < NR_counter; i++) {
+                snprintf(filename, sizeof(filename), "%u", i);
+                dir = oprofilefs_mkdir(sb, root, filename);
+
+                oprofilefs_create_ulong(sb, dir, "enabled",
+                                &counter[i].enabled);
+                oprofilefs_create_ulong(sb, dir, "event",
+                                &counter[i].event);
+                oprofilefs_create_ulong(sb, dir, "count",
+                                &counter[i].count);
+
+                /* Dummy entries */
+                oprofilefs_create_ulong(sb, dir, "kernel",
+                                &counter[i].kernel);
+                oprofilefs_create_ulong(sb, dir, "user",
+                                &counter[i].user);
+                oprofilefs_create_ulong(sb, dir, "unit_mask",
+                                &counter[i].unit_mask);
+        }
+
+        return 0;
+}
+
+static int avr32_perf_counter_setup(void)
+{
+        struct avr32_perf_counter *ctr;
+        u32 pccr;
+        int ret;
+        int i;
+
+        pr_debug("avr32_perf_counter_setup\n");
+
+        if (sysreg_read(PCCR) & SYSREG_BIT(PCCR_E)) {
+                printk(KERN_ERR
+                        "oprofile: setup: perf counter already enabled\n");
+                return -EBUSY;
+        }
+
+        ret = request_irq(AVR32_PERFCTR_IRQ_GROUP,
+                        avr32_perf_counter_interrupt, IRQF_SHARED,
+                        "oprofile", counter);
+        if (ret)
+                return ret;
+
+        avr32_perf_counter_reset();
+
+        pccr = 0;
+        for (i = PCCNT; i < NR_counter; i++) {
+                ctr = &counter[i];
+                if (!ctr->enabled)
+                        continue;
+
+                pr_debug("enabling counter %d...\n", i);
+
+                pccr |= ctr->ie_mask;
+
+                switch (i) {
+                case PCCNT:
+                        /* PCCNT always counts cycles, so no events */
+                        sysreg_write(PCCNT, -ctr->count);
+                        break;
+                case PCNT0:
+                        pccr |= SYSREG_BF(CONF0, ctr->event);
+                        sysreg_write(PCNT0, -ctr->count);
+                        break;
+                case PCNT1:
+                        pccr |= SYSREG_BF(CONF1, ctr->event);
+                        sysreg_write(PCNT1, -ctr->count);
+                        break;
+                }
+        }
+
+        pr_debug("oprofile: writing 0x%x to PCCR...\n", pccr);
+
+        sysreg_write(PCCR, pccr);
+
+        return 0;
+}
+
+static void avr32_perf_counter_shutdown(void)
+{
+        pr_debug("avr32_perf_counter_shutdown\n");
+
+        avr32_perf_counter_reset();
+        free_irq(AVR32_PERFCTR_IRQ_GROUP, counter);
+}
+
+static int avr32_perf_counter_start(void)
+{
+        pr_debug("avr32_perf_counter_start\n");
+
+        sysreg_write(PCCR, sysreg_read(PCCR) | SYSREG_BIT(PCCR_E));
+
+        return 0;
+}
+
+static void avr32_perf_counter_stop(void)
+{
+        pr_debug("avr32_perf_counter_stop\n");
+
+        sysreg_write(PCCR, sysreg_read(PCCR) & ~SYSREG_BIT(PCCR_E));
+}
+
+static struct oprofile_operations avr32_perf_counter_ops __initdata = {
+        .create_files   = avr32_perf_counter_create_files,
+        .setup          = avr32_perf_counter_setup,
+        .shutdown       = avr32_perf_counter_shutdown,
+        .start          = avr32_perf_counter_start,
+        .stop           = avr32_perf_counter_stop,
+        .cpu_type       = "avr32",
+};
+
+int __init oprofile_arch_init(struct oprofile_operations *ops)
+{
+        if (!(current_cpu_data.features & AVR32_FEATURE_PCTR))
+                return -ENODEV;
+
+        memcpy(ops, &avr32_perf_counter_ops,
+                        sizeof(struct oprofile_operations));
+
+        printk(KERN_INFO "oprofile: using AVR32 performance monitoring.\n");
+
+        return 0;
+}
+
+void oprofile_arch_exit(void)
+{
+
+}