1 files changed, 85 insertions, 0 deletions
diff --git a/arch/arm/kernel/smp_scu.c b/arch/arm/kernel/smp_scu.c
new file mode 100644
index 00000000..cb7dd40e
--- /dev/null
+++ b/arch/arm/kernel/smp_scu.c
@@ -0,0 +1,85 @@
+/*
+ *  linux/arch/arm/kernel/smp_scu.c
+ *
+ *  Copyright (C) 2002 ARM Ltd.
+ *  All Rights Reserved
+ *
+ * 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.
+ */
+#include <linux/init.h>
+#include <linux/io.h>
+
+#include <asm/smp_scu.h>
+#include <asm/cacheflush.h>
+#include <asm/cputype.h>
+
+#define SCU_CTRL		0x00
+#define SCU_CONFIG		0x04
+#define SCU_CPU_STATUS		0x08
+#define SCU_INVALIDATE		0x0c
+#define SCU_FPGA_REVISION	0x10
+
+/*
+ * Get the number of CPU cores from the SCU configuration
+ */
+unsigned int __init scu_get_core_count(void __iomem *scu_base)
+{
+	unsigned int ncores = __raw_readl(scu_base + SCU_CONFIG);
+	return (ncores & 0x03) + 1;
+}
+
+/*
+ * Enable the SCU
+ */
+void __init scu_enable(void __iomem *scu_base)
+{
+	u32 scu_ctrl;
+
+#ifdef CONFIG_ARM_ERRATA_764369
+	/* Cortex-A9 only */
+	if ((read_cpuid(CPUID_ID) & 0xff0ffff0) == 0x410fc090) {
+		scu_ctrl = __raw_readl(scu_base + 0x30);
+		if (!(scu_ctrl & 1))
+			__raw_writel(scu_ctrl | 0x1, scu_base + 0x30);
+	}
+#endif
+
+	scu_ctrl = __raw_readl(scu_base + SCU_CTRL);
+	/* already enabled? */
+	if (scu_ctrl & 1)
+		return;
+
+	scu_ctrl |= 1;
+	__raw_writel(scu_ctrl, scu_base + SCU_CTRL);
+
+	/*
+	 * Ensure that the data accessed by CPU0 before the SCU was
+	 * initialised is visible to the other CPUs.
+	 */
+	flush_cache_all();
+}
+
+/*
+ * Set the executing CPUs power mode as defined.  This will be in
+ * preparation for it executing a WFI instruction.
+ *
+ * This function must be called with preemption disabled, and as it
+ * has the side effect of disabling coherency, caches must have been
+ * flushed.  Interrupts must also have been disabled.
+ */
+int scu_power_mode(void __iomem *scu_base, unsigned int mode)
+{
+	unsigned int val;
+	int cpu = smp_processor_id();
+
+	if (mode > 3 || mode == 1 || cpu > 3)
+		return -EINVAL;
+
+	val = __raw_readb(scu_base + SCU_CPU_STATUS + cpu) & ~0x03;
+	val |= mode;
+	__raw_writeb(val, scu_base + SCU_CPU_STATUS + cpu);
+
+	return 0;
+}