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5fd0f12017
Previously all pending events were handled on return of exceptions in process context. This was causing threads that run in userspace and take no exceptions not handle their pending events indefinitely. Now scheduler handles them in irq context as well.
82 lines
2.0 KiB
C
82 lines
2.0 KiB
C
/*
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* Kernel irq handling (core irqs like timer). Also hope to add thread-level
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* irq handling in the future.
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*
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* Copyright (C) 2007 Bahadir Balban
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*
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*/
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#include <l4/config.h>
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#include <l4/macros.h>
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#include <l4/generic/scheduler.h>
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#include <l4/generic/platform.h>
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#include <l4/generic/tcb.h>
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#include <l4/generic/irq.h>
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#include <l4/lib/mutex.h>
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#include <l4/lib/printk.h>
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#include INC_PLAT(irq.h)
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#include INC_ARCH(exception.h)
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/* This enables the lower chip on the current chip, if such chaining exists. */
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static inline void cascade_irq_chip(struct irq_chip *this_chip)
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{
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if (this_chip->cascade >= 0) {
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BUG_ON(IRQ_CHIPS_MAX == 1);
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this_chip->ops.unmask(this_chip->cascade);
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}
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}
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void irq_controllers_init(void)
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{
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struct irq_chip *this_chip;
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for (int i = 0; i < IRQ_CHIPS_MAX; i++) {
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this_chip = irq_chip_array + i;
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/* Initialise the irq chips (e.g. reset all registers) */
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this_chip->ops.init();
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/* Enable cascaded irqs if needed */
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cascade_irq_chip(this_chip);
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}
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}
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int global_irq_index(void)
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{
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struct irq_chip *this_chip;
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int irq_index = 0;
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/* Loop over irq chips from top to bottom until
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* the actual irq on the lowest chip is found */
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for (int i = 0; i < IRQ_CHIPS_MAX; i++) {
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this_chip = irq_chip_array + i;
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BUG_ON((irq_index = this_chip->ops.read_irq()) < 0);
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if (irq_index != this_chip->cascade) {
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irq_index += this_chip->offset;
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/* Found the real irq, return */
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break;
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}
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/* Hit the cascading irq. Continue on next irq chip. */
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}
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return irq_index;
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}
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void do_irq(void)
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{
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int irq_index = global_irq_index();
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struct irq_desc *this_irq = irq_desc_array + irq_index;
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/* TODO: This can be easily done few instructions quicker by some
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* immediate read/disable/enable_all(). We stick with this clear
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* implementation for now. */
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irq_disable(irq_index);
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enable_irqs();
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/* TODO: Call irq_thread_notify(irq_index) for threaded irqs. */
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BUG_ON(!this_irq->handler);
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if (this_irq->handler() != IRQ_HANDLED) {
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printk("Spurious or broken irq\n"); BUG();
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}
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irq_enable(irq_index);
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}
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