1 files changed, 109 insertions, 1 deletions

diff --git a/arch/sparc/oprofile/init.c b/arch/sparc/oprofile/init.c
index 17bb6035069b..e979dcd77726 100644
--- a/arch/sparc/oprofile/init.c
+++ b/arch/sparc/oprofile/init.c
@@ -12,9 +12,117 @@
 #include <linux/errno.h>
 #include <linux/init.h>
  
+#ifdef CONFIG_SPARC64
+#include <asm/spitfire.h>
+#include <asm/cpudata.h>
+#include <asm/irq.h>
+
+static int nmi_enabled;
+
+static u64 picl_value(void)
+{
+	u32 delta = local_cpu_data().clock_tick / HZ;
+
+	return (0 - delta) & 0xffffffff;
+}
+
+#define PCR_PIC_PRIV	0x1 /* PIC access is privileged */
+#define PCR_STRACE	0x2 /* Trace supervisor events  */
+#define PCR_UTRACE	0x4 /* Trace user events        */
+
+static void nmi_handler(struct pt_regs *regs)
+{
+	write_pcr(PCR_PIC_PRIV);
+
+	if (nmi_enabled) {
+		oprofile_add_sample(regs, 0);
+
+		write_pic(picl_value());
+		write_pcr(PCR_PIC_PRIV | PCR_STRACE | PCR_UTRACE);
+	}
+}
+
+/* We count "clock cycle" events in the lower 32-bit PIC.
+ * Then configure it such that it overflows every HZ, and thus
+ * generates a level 15 interrupt at that frequency.
+ */
+static void cpu_nmi_start(void *_unused)
+{
+	write_pcr(PCR_PIC_PRIV);
+	write_pic(picl_value());
+
+	/* Bit 0: PIC access is privileged
+	 * Bit 1: Supervisor Trace
+	 * Bit 2: User Trace
+	 *
+	 * And the event selection code for cpu cycles is zero.
+	 */
+	write_pcr(PCR_PIC_PRIV | PCR_STRACE | PCR_UTRACE);
+}
+
+static void cpu_nmi_stop(void *_unused)
+{
+	write_pcr(PCR_PIC_PRIV);
+}
+
+static int nmi_start(void)
+{
+	int err = register_perfctr_intr(nmi_handler);
+
+	if (!err) {
+		nmi_enabled = 1;
+		wmb();
+		err = on_each_cpu(cpu_nmi_start, NULL, 1);
+		if (err) {
+			nmi_enabled = 0;
+			wmb();
+			on_each_cpu(cpu_nmi_stop, NULL, 1);
+			release_perfctr_intr(nmi_handler);
+		}
+	}
+
+	return err;
+}
+
+static void nmi_stop(void)
+{
+	nmi_enabled = 0;
+	wmb();
+
+	on_each_cpu(cpu_nmi_stop, NULL, 1);
+	release_perfctr_intr(nmi_handler);
+	synchronize_sched();
+}
+
+static int oprofile_nmi_init(struct oprofile_operations *ops)
+{
+	if (tlb_type != cheetah && tlb_type != cheetah_plus)
+		return -ENODEV;
+
+	ops->create_files = NULL;
+	ops->setup = NULL;
+	ops->shutdown = NULL;
+	ops->start = nmi_start;
+	ops->stop = nmi_stop;
+	ops->cpu_type = "timer";
+
+	printk(KERN_INFO "oprofile: Using perfctr based NMI timer interrupt.\n");
+
+	return 0;
+}
+#endif
+
 int __init oprofile_arch_init(struct oprofile_operations *ops)
 {
-	return -ENODEV;
+	int ret = -ENODEV;
+
+#ifdef CONFIG_SPARC64
+	ret = oprofile_nmi_init(ops);
+	if (!ret)
+		return ret;
+#endif
+
+	return ret;
 }