54 lines
1.4 KiB
C
54 lines
1.4 KiB
C
// Helpers for working with i8259 interrupt controller.
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//
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// Copyright (C) 2008 Kevin O'Connor <kevin@koconnor.net>
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// Copyright (C) 2002 MandrakeSoft S.A.
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//
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// This file may be distributed under the terms of the GNU LGPLv3 license.
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#include "pic.h" // get_pic1_isr
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#include "util.h" // dprintf
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#include "config.h" // CONFIG_*
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void
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pic_setup()
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{
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dprintf(3, "init pic\n");
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// Send ICW1 (select OCW1 + will send ICW4)
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outb(0x11, PORT_PIC1_CMD);
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outb(0x11, PORT_PIC2_CMD);
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// Send ICW2 (base irqs: 0x08-0x0f for irq0-7, 0x70-0x77 for irq8-15)
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outb(0x08, PORT_PIC1_DATA);
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outb(0x70, PORT_PIC2_DATA);
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// Send ICW3 (cascaded pic ids)
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outb(0x04, PORT_PIC1_DATA);
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outb(0x02, PORT_PIC2_DATA);
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// Send ICW4 (enable 8086 mode)
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outb(0x01, PORT_PIC1_DATA);
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outb(0x01, PORT_PIC2_DATA);
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// Mask all irqs (except cascaded PIC2 irq)
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outb(~PIC1_IRQ2, PORT_PIC1_DATA);
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outb(~0, PORT_PIC2_DATA);
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}
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// Handler for otherwise unused hardware irqs.
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void VISIBLE16
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handle_hwpic1(struct bregs *regs)
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{
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u8 isr = get_pic1_isr();
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dprintf(DEBUG_ISR_hwpic1, "Got noisy pic1 irq %x\n", isr);
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isr &= ~PIC1_IRQ2; // don't ever mask the cascaded irq
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if (isr)
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mask_pic1(isr);
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eoi_pic1();
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}
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void VISIBLE16
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handle_hwpic2(struct bregs *regs)
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{
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u8 isr = get_pic2_isr();
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dprintf(DEBUG_ISR_hwpic2, "Got noisy pic2 irq %x\n", isr);
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if (isr)
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mask_pic2(isr);
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eoi_pic2();
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}
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