2 * linux/arch/arm/kernel/smp_scu.c
4 * Copyright (C) 2002 ARM Ltd.
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
11 #include <linux/init.h>
14 #include <asm/smp_scu.h>
15 #include <asm/cacheflush.h>
18 #define SCU_CONFIG 0x04
19 #define SCU_CPU_STATUS 0x08
20 #define SCU_INVALIDATE 0x0c
21 #define SCU_FPGA_REVISION 0x10
25 * Get the number of CPU cores from the SCU configuration
27 unsigned int __init scu_get_core_count(void __iomem *scu_base)
29 unsigned int ncores = __raw_readl(scu_base + SCU_CONFIG);
30 return (ncores & 0x03) + 1;
36 void __init scu_enable(void __iomem *scu_base)
40 scu_ctrl = __raw_readl(scu_base + SCU_CTRL);
41 /* already enabled? */
46 __raw_writel(scu_ctrl, scu_base + SCU_CTRL);
49 * Ensure that the data accessed by CPU0 before the SCU was
50 * initialised is visible to the other CPUs.
57 * Set the executing CPUs power mode as defined. This will be in
58 * preparation for it executing a WFI instruction.
60 * This function must be called with preemption disabled, and as it
61 * has the side effect of disabling coherency, caches must have been
62 * flushed. Interrupts must also have been disabled.
64 int scu_power_mode(void __iomem *scu_base, unsigned int mode)
67 int cpu = smp_processor_id();
69 if (mode > 3 || mode == 1 || cpu > 3)
72 val = __raw_readb(scu_base + SCU_CPU_STATUS + cpu) & ~0x03;
74 __raw_writeb(val, scu_base + SCU_CPU_STATUS + cpu);