arch/tile/include/asm/irq.h

   1 /*
   2  * Copyright 2010 Tilera Corporation. All Rights Reserved.
   3  *
   4  *   This program is free software; you can redistribute it and/or
   5  *   modify it under the terms of the GNU General Public License
   6  *   as published by the Free Software Foundation, version 2.
   7  *
   8  *   This program is distributed in the hope that it will be useful, but
   9  *   WITHOUT ANY WARRANTY; without even the implied warranty of
  10  *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
  11  *   NON INFRINGEMENT.  See the GNU General Public License for
  12  *   more details.
  13  */
  14
  15 #ifndef _ASM_TILE_IRQ_H
  16 #define _ASM_TILE_IRQ_H
  17
  18 #include <linux/hardirq.h>
  19
  20 /* The hypervisor interface provides 32 IRQs. */
  21 #define NR_IRQS 32
  22
  23 /* IRQ numbers used for linux IPIs. */
  24 #define IRQ_RESCHEDULE 1
  25
  26 void ack_bad_irq(unsigned int irq);
  27
  28 /*
  29  * Different ways of handling interrupts.  Tile interrupts are always
  30  * per-cpu; there is no global interrupt controller to implement
  31  * enable/disable.  Most onboard devices can send their interrupts to
  32  * many tiles at the same time, and Tile-specific drivers know how to
  33  * deal with this.
  34  *
  35  * However, generic devices (usually PCIE based, sometimes GPIO)
  36  * expect that interrupts will fire on a single core at a time and
  37  * that the irq can be enabled or disabled from any core at any time.
  38  * We implement this by directing such interrupts to a single core.
  39  *
  40  * One added wrinkle is that PCI interrupts can be either
  41  * hardware-cleared (legacy interrupts) or software cleared (MSI).
  42  * Other generic device systems (GPIO) are always software-cleared.
  43  *
  44  * The enums below are used by drivers for onboard devices, including
  45  * the internals of PCI root complex and GPIO.  They allow the driver
  46  * to tell the generic irq code what kind of interrupt is mapped to a
  47  * particular IRQ number.
  48  */
  49 enum {
  50         /* per-cpu interrupt; use enable/disable_percpu_irq() to mask */
  51         TILE_IRQ_PERCPU,
  52         /* global interrupt, hardware responsible for clearing. */
  53         TILE_IRQ_HW_CLEAR,
  54         /* global interrupt, software responsible for clearing. */
  55         TILE_IRQ_SW_CLEAR,
  56 };
  57
  58
  59 /*
  60  * Paravirtualized drivers should call this when they dynamically
  61  * allocate a new IRQ or discover an IRQ that was pre-allocated by the
  62  * hypervisor for use with their particular device.  This gives the
  63  * IRQ subsystem an opportunity to do interrupt-type-specific
  64  * initialization.
  65  *
  66  * ISSUE: We should modify this API so that registering anything
  67  * except percpu interrupts also requires providing callback methods
  68  * for enabling and disabling the interrupt.  This would allow the
  69  * generic IRQ code to proxy enable/disable_irq() calls back into the
  70  * PCI subsystem, which in turn could enable or disable the interrupt
  71  * at the PCI shim.
  72  */
  73 void tile_irq_activate(unsigned int irq, int tile_irq_type);
  74
  75 /*
  76  * For onboard, non-PCI (e.g. TILE_IRQ_PERCPU) devices, drivers know
  77  * how to use enable/disable_percpu_irq() to manage interrupts on each
  78  * core.  We can't use the generic enable/disable_irq() because they
  79  * use a single reference count per irq, rather than per cpu per irq.
  80  */
  81 void enable_percpu_irq(unsigned int irq);
  82 void disable_percpu_irq(unsigned int irq);
  83
  84
  85 void setup_irq_regs(void);
  86
  87 #endif /* _ASM_TILE_IRQ_H */