linux-stable/include/linux/irqchip/arm-gic.h
Nicolas Pitre 10d9eb8a17 drivers: irq-chip: irq-gic: introduce gic_cpu_if_down()
When processors are about to hit low power states, the assertion of
standbywfi signal, triggered by the wfi instruction, is essential to
entering low power modes. If an IRQ is pending on the processor at the
time wfi is issued, the wfi instruction completes and the processor
restarts execution without asserting the standbywfi signal. Depending
on the platform power controller HW this behaviour can be acceptable or
not; if this behaviour must be prevented software should be provided
with a way to disable the routing of interrupts to the core IRQ pins.

On systems where raw GIC distributor interrupts are connected to the power
controller as wake-up events (hence the power controller still senses
IRQs and can wake up cores upon IRQ pending), the GIC CPU interface can
be disabled on power down, so that the GIC CPU IF output is gated and wfi
cannot complete, thereby preventing the standbywfi issue.

This patch adds a simple function to the GIC driver that allows to
disable the GIC CPU IF from power down procedures.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
[rewrote commit log]

Signed-off-by: Olof Johansson <olof@lixom.net>
2013-08-28 11:28:43 -07:00

79 lines
2.1 KiB
C

/*
* include/linux/irqchip/arm-gic.h
*
* Copyright (C) 2002 ARM Limited, 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.
*/
#ifndef __LINUX_IRQCHIP_ARM_GIC_H
#define __LINUX_IRQCHIP_ARM_GIC_H
#define GIC_CPU_CTRL 0x00
#define GIC_CPU_PRIMASK 0x04
#define GIC_CPU_BINPOINT 0x08
#define GIC_CPU_INTACK 0x0c
#define GIC_CPU_EOI 0x10
#define GIC_CPU_RUNNINGPRI 0x14
#define GIC_CPU_HIGHPRI 0x18
#define GIC_DIST_CTRL 0x000
#define GIC_DIST_CTR 0x004
#define GIC_DIST_IGROUP 0x080
#define GIC_DIST_ENABLE_SET 0x100
#define GIC_DIST_ENABLE_CLEAR 0x180
#define GIC_DIST_PENDING_SET 0x200
#define GIC_DIST_PENDING_CLEAR 0x280
#define GIC_DIST_ACTIVE_SET 0x300
#define GIC_DIST_ACTIVE_CLEAR 0x380
#define GIC_DIST_PRI 0x400
#define GIC_DIST_TARGET 0x800
#define GIC_DIST_CONFIG 0xc00
#define GIC_DIST_SOFTINT 0xf00
#define GICH_HCR 0x0
#define GICH_VTR 0x4
#define GICH_VMCR 0x8
#define GICH_MISR 0x10
#define GICH_EISR0 0x20
#define GICH_EISR1 0x24
#define GICH_ELRSR0 0x30
#define GICH_ELRSR1 0x34
#define GICH_APR 0xf0
#define GICH_LR0 0x100
#define GICH_HCR_EN (1 << 0)
#define GICH_HCR_UIE (1 << 1)
#define GICH_LR_VIRTUALID (0x3ff << 0)
#define GICH_LR_PHYSID_CPUID_SHIFT (10)
#define GICH_LR_PHYSID_CPUID (7 << GICH_LR_PHYSID_CPUID_SHIFT)
#define GICH_LR_STATE (3 << 28)
#define GICH_LR_PENDING_BIT (1 << 28)
#define GICH_LR_ACTIVE_BIT (1 << 29)
#define GICH_LR_EOI (1 << 19)
#define GICH_MISR_EOI (1 << 0)
#define GICH_MISR_U (1 << 1)
#ifndef __ASSEMBLY__
struct device_node;
extern struct irq_chip gic_arch_extn;
void gic_init_bases(unsigned int, int, void __iomem *, void __iomem *,
u32 offset, struct device_node *);
void gic_cascade_irq(unsigned int gic_nr, unsigned int irq);
void gic_cpu_if_down(void);
static inline void gic_init(unsigned int nr, int start,
void __iomem *dist , void __iomem *cpu)
{
gic_init_bases(nr, start, dist, cpu, 0, NULL);
}
#endif /* __ASSEMBLY */
#endif