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-rw-r--r--arch/ppc/kernel/perfmon.c93
1 files changed, 93 insertions, 0 deletions
diff --git a/arch/ppc/kernel/perfmon.c b/arch/ppc/kernel/perfmon.c
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+++ b/arch/ppc/kernel/perfmon.c
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+/* kernel/perfmon.c
+ * PPC 32 Performance Monitor Infrastructure
+ *
+ * Author: Andy Fleming
+ * Copyright (c) 2004 Freescale Semiconductor, Inc
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/stddef.h>
+#include <linux/unistd.h>
+#include <linux/ptrace.h>
+#include <linux/slab.h>
+#include <linux/user.h>
+#include <linux/a.out.h>
+#include <linux/interrupt.h>
+#include <linux/config.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/prctl.h>
+
+#include <asm/pgtable.h>
+#include <asm/uaccess.h>
+#include <asm/system.h>
+#include <asm/io.h>
+#include <asm/reg.h>
+#include <asm/xmon.h>
+
+/* A lock to regulate grabbing the interrupt */
+DEFINE_SPINLOCK(perfmon_lock);
+
+#ifdef CONFIG_FSL_BOOKE
+static void dummy_perf(struct pt_regs *regs)
+{
+ unsigned int pmgc0 = mfpmr(PMRN_PMGC0);
+
+ pmgc0 &= ~PMGC0_PMIE;
+ mtpmr(PMRN_PMGC0, pmgc0);
+}
+
+#else
+/* Ensure exceptions are disabled */
+
+static void dummy_perf(struct pt_regs *regs)
+{
+ unsigned int mmcr0 = mfspr(SPRN_MMCR0);
+
+ mmcr0 &= ~MMCR0_PMXE;
+ mtspr(SPRN_MMCR0, mmcr0);
+}
+#endif
+
+void (*perf_irq)(struct pt_regs *) = dummy_perf;
+
+/* Grab the interrupt, if it's free.
+ * Returns 0 on success, -1 if the interrupt is taken already */
+int request_perfmon_irq(void (*handler)(struct pt_regs *))
+{
+ int err = 0;
+
+ spin_lock(&perfmon_lock);
+
+ if (perf_irq == dummy_perf)
+ perf_irq = handler;
+ else {
+ pr_info("perfmon irq already handled by %p\n", perf_irq);
+ err = -1;
+ }
+
+ spin_unlock(&perfmon_lock);
+
+ return err;
+}
+
+void free_perfmon_irq(void)
+{
+ spin_lock(&perfmon_lock);
+
+ perf_irq = dummy_perf;
+
+ spin_unlock(&perfmon_lock);
+}
+
+EXPORT_SYMBOL(perf_irq);
+EXPORT_SYMBOL(request_perfmon_irq);
+EXPORT_SYMBOL(free_perfmon_irq);