[ARM] oprofile: add ARM11 core support

Add basic support for the ARM11 profiling hardware.  This is shared
between the ARM11 UP and ARM11 SMP oprofile support code.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 162 insertions, 0 deletions

diff --git a/arch/arm/oprofile/op_model_arm11_core.c b/arch/arm/oprofile/op_model_arm11_core.c
new file mode 100644
index 000000000000..ad80752cb9fb
--- /dev/null
+++ b/arch/arm/oprofile/op_model_arm11_core.c
@@ -0,0 +1,162 @@
+/**
+ * @file op_model_arm11_core.c
+ * ARM11 Event Monitor Driver
+ * @remark Copyright 2004 ARM SMP Development Team
+ */
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/oprofile.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/smp.h>
+
+#include "op_counter.h"
+#include "op_arm_model.h"
+#include "op_model_arm11_core.h"
+
+/*
+ * ARM11 PMU support
+ */
+static inline void arm11_write_pmnc(u32 val)
+{
+	/* upper 4bits and 7, 11 are write-as-0 */
+	val &= 0x0ffff77f;
+	asm volatile("mcr p15, 0, %0, c15, c12, 0" : : "r" (val));
+}
+
+static inline u32 arm11_read_pmnc(void)
+{
+	u32 val;
+	asm volatile("mrc p15, 0, %0, c15, c12, 0" : "=r" (val));
+	return val;
+}
+
+static void arm11_reset_counter(unsigned int cnt)
+{
+	u32 val = -(u32)counter_config[CPU_COUNTER(smp_processor_id(), cnt)].count;
+	switch (cnt) {
+	case CCNT:
+		asm volatile("mcr p15, 0, %0, c15, c12, 1" : : "r" (val));
+		break;
+
+	case PMN0:
+		asm volatile("mcr p15, 0, %0, c15, c12, 2" : : "r" (val));
+		break;
+
+	case PMN1:
+		asm volatile("mcr p15, 0, %0, c15, c12, 3" : : "r" (val));
+		break;
+	}
+}
+
+int arm11_setup_pmu(void)
+{
+	unsigned int cnt;
+	u32 pmnc;
+
+	if (arm11_read_pmnc() & PMCR_E) {
+		printk(KERN_ERR "oprofile: CPU%u PMU still enabled when setup new event counter.\n", smp_processor_id());
+		return -EBUSY;
+	}
+
+	/* initialize PMNC, reset overflow, D bit, C bit and P bit. */
+	arm11_write_pmnc(PMCR_OFL_PMN0 | PMCR_OFL_PMN1 | PMCR_OFL_CCNT |
+			 PMCR_C | PMCR_P);
+
+	for (pmnc = 0, cnt = PMN0; cnt <= CCNT; cnt++) {
+		unsigned long event;
+
+		if (!counter_config[CPU_COUNTER(smp_processor_id(), cnt)].enabled)
+			continue;
+
+		event = counter_config[CPU_COUNTER(smp_processor_id(), cnt)].event & 255;
+
+		/*
+		 * Set event (if destined for PMNx counters)
+		 */
+		if (cnt == PMN0) {
+			pmnc |= event << 20;
+		} else if (cnt == PMN1) {
+			pmnc |= event << 12;
+		}
+
+		/*
+		 * We don't need to set the event if it's a cycle count
+		 * Enable interrupt for this counter
+		 */
+		pmnc |= PMCR_IEN_PMN0 << cnt;
+		arm11_reset_counter(cnt);
+	}
+	arm11_write_pmnc(pmnc);
+
+	return 0;
+}
+
+int arm11_start_pmu(void)
+{
+	arm11_write_pmnc(arm11_read_pmnc() | PMCR_E);
+	return 0;
+}
+
+int arm11_stop_pmu(void)
+{
+	unsigned int cnt;
+
+	arm11_write_pmnc(arm11_read_pmnc() & ~PMCR_E);
+
+	for (cnt = PMN0; cnt <= CCNT; cnt++)
+		arm11_reset_counter(cnt);
+
+	return 0;
+}
+
+/*
+ * CPU counters' IRQ handler (one IRQ per CPU)
+ */
+static irqreturn_t arm11_pmu_interrupt(int irq, void *arg)
+{
+	struct pt_regs *regs = get_irq_regs();
+	unsigned int cnt;
+	u32 pmnc;
+
+	pmnc = arm11_read_pmnc();
+
+	for (cnt = PMN0; cnt <= CCNT; cnt++) {
+		if ((pmnc & (PMCR_OFL_PMN0 << cnt)) && (pmnc & (PMCR_IEN_PMN0 << cnt))) {
+			arm11_reset_counter(cnt);
+			oprofile_add_sample(regs, CPU_COUNTER(smp_processor_id(), cnt));
+		}
+	}
+	/* Clear counter flag(s) */
+	arm11_write_pmnc(pmnc);
+	return IRQ_HANDLED;
+}
+
+int arm11_request_interrupts(int *irqs, int nr)
+{
+	unsigned int i;
+	int ret = 0;
+
+	for(i = 0; i < nr; i++) {
+		ret = request_irq(irqs[i], arm11_pmu_interrupt, IRQF_DISABLED, "CP15 PMU", NULL);
+		if (ret != 0) {
+			printk(KERN_ERR "oprofile: unable to request IRQ%u for MPCORE-EM\n",
+			       irqs[i]);
+			break;
+		}
+	}
+
+	if (i != nr)
+		while (i-- != 0)
+			free_irq(irqs[i], NULL);
+
+	return ret;
+}
+
+void arm11_release_interrupts(int *irqs, int nr)
+{
+	unsigned int i;
+
+	for (i = 0; i < nr; i++)
+		free_irq(irqs[i], NULL);
+}