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/*
* Copyright 2010 Tilera Corporation. 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
* as published by the Free Software Foundation, version 2.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
* NON INFRINGEMENT. See the GNU General Public License for
* more details.
*/
#ifndef _ASM_TILE_IRQ_H
#define _ASM_TILE_IRQ_H
#include <linux/hardirq.h>
/* The hypervisor interface provides 32 IRQs. */
#define NR_IRQS 32
/* IRQ numbers used for linux IPIs. */
#define IRQ_RESCHEDULE 1
void ack_bad_irq(unsigned int irq);
/*
* Different ways of handling interrupts. Tile interrupts are always
* per-cpu; there is no global interrupt controller to implement
* enable/disable. Most onboard devices can send their interrupts to
* many tiles at the same time, and Tile-specific drivers know how to
* deal with this.
*
* However, generic devices (usually PCIE based, sometimes GPIO)
* expect that interrupts will fire on a single core at a time and
* that the irq can be enabled or disabled from any core at any time.
* We implement this by directing such interrupts to a single core.
*
* One added wrinkle is that PCI interrupts can be either
* hardware-cleared (legacy interrupts) or software cleared (MSI).
* Other generic device systems (GPIO) are always software-cleared.
*
* The enums below are used by drivers for onboard devices, including
* the internals of PCI root complex and GPIO. They allow the driver
* to tell the generic irq code what kind of interrupt is mapped to a
* particular IRQ number.
*/
enum {
/* per-cpu interrupt; use enable/disable_percpu_irq() to mask */
TILE_IRQ_PERCPU,
/* global interrupt, hardware responsible for clearing. */
TILE_IRQ_HW_CLEAR,
/* global interrupt, software responsible for clearing. */
TILE_IRQ_SW_CLEAR,
};
/*
* Paravirtualized drivers should call this when they dynamically
* allocate a new IRQ or discover an IRQ that was pre-allocated by the
* hypervisor for use with their particular device. This gives the
* IRQ subsystem an opportunity to do interrupt-type-specific
* initialization.
*
* ISSUE: We should modify this API so that registering anything
* except percpu interrupts also requires providing callback methods
* for enabling and disabling the interrupt. This would allow the
* generic IRQ code to proxy enable/disable_irq() calls back into the
* PCI subsystem, which in turn could enable or disable the interrupt
* at the PCI shim.
*/
void tile_irq_activate(unsigned int irq, int tile_irq_type);
/*
* For onboard, non-PCI (e.g. TILE_IRQ_PERCPU) devices, drivers know
* how to use enable/disable_percpu_irq() to manage interrupts on each
* core. We can't use the generic enable/disable_irq() because they
* use a single reference count per irq, rather than per cpu per irq.
*/
void enable_percpu_irq(unsigned int irq);
void disable_percpu_irq(unsigned int irq);
void setup_irq_regs(void);
#endif /* _ASM_TILE_IRQ_H */
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