afd9b5b0b7
This commit implements pic_eoi(int irq) and a helper macro PIC_INT(irq). This first checks which PICs should be 'acked' given an IRQ number, while the macro returns the actual system interrupt number for the IRQ according to the offset used on the PIC initialization.
87 lines
3.1 KiB
C
87 lines
3.1 KiB
C
/*
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* Copyright (C) 2015, Intel Corporation. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* 3. Neither the name of the copyright holder nor the names of its
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* contributors may be used to endorse or promote products derived
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* from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
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* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
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* OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#ifndef PIC_H
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#define PIC_H
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#include "helpers.h"
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#define PIC1_CMD_PORT 0x20
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#define PIC1_DATA_PORT 0x21
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#define PIC2_CMD_PORT 0xA0
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#define PIC2_DATA_PORT 0xA1
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#define PIC1_OFFSET 0x20
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#define PIC2_OFFSET PIC1_OFFSET + 8
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/*
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* Returns the actual interrupt number of a given IRQ,
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* no matter which PIC it is part of.
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*/
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#define PIC_INT(a) (a + PIC1_OFFSET)
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void pic_unmask_irq(unsigned int num);
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/* This function initializes the daisy-chained Master and Slave 8259 PICs.
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* It is only called once, so let's give the compiler the option to inline it.
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* For more information about the ICWs, please refer to http://stanislavs.org/helppc/8259.html.
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*/
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static inline void
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pic_init(void)
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{
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/* ICW1: Initialization. */
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outb(PIC1_CMD_PORT, 0x11);
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outb(PIC2_CMD_PORT, 0x11);
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/* ICW2: Remap IRQs by setting an IDT Offset for each PIC. */
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outb(PIC1_DATA_PORT, PIC1_OFFSET);
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outb(PIC2_DATA_PORT, PIC2_OFFSET);
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/* ICW3: Setup Slave to Master's IRQ2. */
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outb(PIC1_DATA_PORT, 0x04);
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outb(PIC2_DATA_PORT, 0x02);
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/* ICW4: Environment setup. Set PIC1 as master and PIC2 as slave. */
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outb(PIC1_DATA_PORT, 0x01);
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outb(PIC2_DATA_PORT, 0x01);
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/* Set the IMR register, masking all hardware interrupts but IRQ 2.
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* We will have to unmask each IRQ when registering them. */
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outb(PIC1_DATA_PORT, 0xfb);
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outb(PIC2_DATA_PORT, 0xff);
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}
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/*
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* This function sends an end-of-interrupt (EOI) to the correct PIC according
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* to the IRQ line number.
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*/
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void pic_eoi(unsigned int irq);
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#endif /* PIC_H */
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