Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
new file mode 100644
index 0000000..2fb0e46
--- /dev/null
+++ b/kernel/irq/handle.c
@@ -0,0 +1,193 @@
+/*
+ * linux/kernel/irq/handle.c
+ *
+ * Copyright (C) 1992, 1998-2004 Linus Torvalds, Ingo Molnar
+ *
+ * This file contains the core interrupt handling code.
+ */
+
+#include <linux/irq.h>
+#include <linux/module.h>
+#include <linux/random.h>
+#include <linux/interrupt.h>
+#include <linux/kernel_stat.h>
+
+#include "internals.h"
+
+/*
+ * Linux has a controller-independent interrupt architecture.
+ * Every controller has a 'controller-template', that is used
+ * by the main code to do the right thing. Each driver-visible
+ * interrupt source is transparently wired to the apropriate
+ * controller. Thus drivers need not be aware of the
+ * interrupt-controller.
+ *
+ * The code is designed to be easily extended with new/different
+ * interrupt controllers, without having to do assembly magic or
+ * having to touch the generic code.
+ *
+ * Controller mappings for all interrupt sources:
+ */
+irq_desc_t irq_desc[NR_IRQS] __cacheline_aligned = {
+ [0 ... NR_IRQS-1] = {
+ .handler = &no_irq_type,
+ .lock = SPIN_LOCK_UNLOCKED
+ }
+};
+
+/*
+ * Generic 'no controller' code
+ */
+static void end_none(unsigned int irq) { }
+static void enable_none(unsigned int irq) { }
+static void disable_none(unsigned int irq) { }
+static void shutdown_none(unsigned int irq) { }
+static unsigned int startup_none(unsigned int irq) { return 0; }
+
+static void ack_none(unsigned int irq)
+{
+ /*
+ * 'what should we do if we get a hw irq event on an illegal vector'.
+ * each architecture has to answer this themself.
+ */
+ ack_bad_irq(irq);
+}
+
+struct hw_interrupt_type no_irq_type = {
+ .typename = "none",
+ .startup = startup_none,
+ .shutdown = shutdown_none,
+ .enable = enable_none,
+ .disable = disable_none,
+ .ack = ack_none,
+ .end = end_none,
+ .set_affinity = NULL
+};
+
+/*
+ * Special, empty irq handler:
+ */
+irqreturn_t no_action(int cpl, void *dev_id, struct pt_regs *regs)
+{
+ return IRQ_NONE;
+}
+
+/*
+ * Have got an event to handle:
+ */
+fastcall int handle_IRQ_event(unsigned int irq, struct pt_regs *regs,
+ struct irqaction *action)
+{
+ int ret, retval = 0, status = 0;
+
+ if (!(action->flags & SA_INTERRUPT))
+ local_irq_enable();
+
+ do {
+ ret = action->handler(irq, action->dev_id, regs);
+ if (ret == IRQ_HANDLED)
+ status |= action->flags;
+ retval |= ret;
+ action = action->next;
+ } while (action);
+
+ if (status & SA_SAMPLE_RANDOM)
+ add_interrupt_randomness(irq);
+ local_irq_disable();
+
+ return retval;
+}
+
+/*
+ * do_IRQ handles all normal device IRQ's (the special
+ * SMP cross-CPU interrupts have their own specific
+ * handlers).
+ */
+fastcall unsigned int __do_IRQ(unsigned int irq, struct pt_regs *regs)
+{
+ irq_desc_t *desc = irq_desc + irq;
+ struct irqaction * action;
+ unsigned int status;
+
+ kstat_this_cpu.irqs[irq]++;
+ if (desc->status & IRQ_PER_CPU) {
+ irqreturn_t action_ret;
+
+ /*
+ * No locking required for CPU-local interrupts:
+ */
+ desc->handler->ack(irq);
+ action_ret = handle_IRQ_event(irq, regs, desc->action);
+ if (!noirqdebug)
+ note_interrupt(irq, desc, action_ret);
+ desc->handler->end(irq);
+ return 1;
+ }
+
+ spin_lock(&desc->lock);
+ desc->handler->ack(irq);
+ /*
+ * REPLAY is when Linux resends an IRQ that was dropped earlier
+ * WAITING is used by probe to mark irqs that are being tested
+ */
+ status = desc->status & ~(IRQ_REPLAY | IRQ_WAITING);
+ status |= IRQ_PENDING; /* we _want_ to handle it */
+
+ /*
+ * If the IRQ is disabled for whatever reason, we cannot
+ * use the action we have.
+ */
+ action = NULL;
+ if (likely(!(status & (IRQ_DISABLED | IRQ_INPROGRESS)))) {
+ action = desc->action;
+ status &= ~IRQ_PENDING; /* we commit to handling */
+ status |= IRQ_INPROGRESS; /* we are handling it */
+ }
+ desc->status = status;
+
+ /*
+ * If there is no IRQ handler or it was disabled, exit early.
+ * Since we set PENDING, if another processor is handling
+ * a different instance of this same irq, the other processor
+ * will take care of it.
+ */
+ if (unlikely(!action))
+ goto out;
+
+ /*
+ * Edge triggered interrupts need to remember
+ * pending events.
+ * This applies to any hw interrupts that allow a second
+ * instance of the same irq to arrive while we are in do_IRQ
+ * or in the handler. But the code here only handles the _second_
+ * instance of the irq, not the third or fourth. So it is mostly
+ * useful for irq hardware that does not mask cleanly in an
+ * SMP environment.
+ */
+ for (;;) {
+ irqreturn_t action_ret;
+
+ spin_unlock(&desc->lock);
+
+ action_ret = handle_IRQ_event(irq, regs, action);
+
+ spin_lock(&desc->lock);
+ if (!noirqdebug)
+ note_interrupt(irq, desc, action_ret);
+ if (likely(!(desc->status & IRQ_PENDING)))
+ break;
+ desc->status &= ~IRQ_PENDING;
+ }
+ desc->status &= ~IRQ_INPROGRESS;
+
+out:
+ /*
+ * The ->end() handler has to deal with interrupts which got
+ * disabled while the handler was running.
+ */
+ desc->handler->end(irq);
+ spin_unlock(&desc->lock);
+
+ return 1;
+}
+
