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linux-next/arch/alpha/kernel/irq_pyxis.c
Ingo Molnar d1bef4ed5f [PATCH] genirq: rename desc->handler to desc->chip
This patch-queue improves the generic IRQ layer to be truly generic, by adding
various abstractions and features to it, without impacting existing
functionality.

While the queue can be best described as "fix and improve everything in the
generic IRQ layer that we could think of", and thus it consists of many
smaller features and lots of cleanups, the one feature that stands out most is
the new 'irq chip' abstraction.

The irq-chip abstraction is about describing and coding and IRQ controller
driver by mapping its raw hardware capabilities [and quirks, if needed] in a
straightforward way, without having to think about "IRQ flow"
(level/edge/etc.) type of details.

This stands in contrast with the current 'irq-type' model of genirq
architectures, which 'mixes' raw hardware capabilities with 'flow' details.
The patchset supports both types of irq controller designs at once, and
converts i386 and x86_64 to the new irq-chip design.

As a bonus side-effect of the irq-chip approach, chained interrupt controllers
(master/slave PIC constructs, etc.) are now supported by design as well.

The end result of this patchset intends to be simpler architecture-level code
and more consolidation between architectures.

We reused many bits of code and many concepts from Russell King's ARM IRQ
layer, the merging of which was one of the motivations for this patchset.

This patch:

rename desc->handler to desc->chip.

Originally i did not want to do this, because it's a big patch.  But having
both "desc->handler", "desc->handle_irq" and "action->handler" caused a
large degree of confusion and made the code appear alot less clean than it
truly is.

I have also attempted a dual approach as well by introducing a
desc->chip alias - but that just wasnt robust enough and broke
frequently.

So lets get over with this quickly.  The conversion was done automatically
via scripts and converts all the code in the kernel.

This renaming patch is the first one amongst the patches, so that the
remaining patches can stay flexible and can be merged and split up
without having some big monolithic patch act as a merge barrier.

[akpm@osdl.org: build fix]
[akpm@osdl.org: another build fix]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-29 10:26:21 -07:00

128 lines
2.5 KiB
C

/*
* linux/arch/alpha/kernel/irq_pyxis.c
*
* Based on code written by David A Rusling (david.rusling@reo.mts.dec.com).
*
* IRQ Code common to all PYXIS core logic chips.
*/
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/irq.h>
#include <asm/io.h>
#include <asm/core_cia.h>
#include "proto.h"
#include "irq_impl.h"
/* Note mask bit is true for ENABLED irqs. */
static unsigned long cached_irq_mask;
static inline void
pyxis_update_irq_hw(unsigned long mask)
{
*(vulp)PYXIS_INT_MASK = mask;
mb();
*(vulp)PYXIS_INT_MASK;
}
static inline void
pyxis_enable_irq(unsigned int irq)
{
pyxis_update_irq_hw(cached_irq_mask |= 1UL << (irq - 16));
}
static void
pyxis_disable_irq(unsigned int irq)
{
pyxis_update_irq_hw(cached_irq_mask &= ~(1UL << (irq - 16)));
}
static unsigned int
pyxis_startup_irq(unsigned int irq)
{
pyxis_enable_irq(irq);
return 0;
}
static void
pyxis_end_irq(unsigned int irq)
{
if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
pyxis_enable_irq(irq);
}
static void
pyxis_mask_and_ack_irq(unsigned int irq)
{
unsigned long bit = 1UL << (irq - 16);
unsigned long mask = cached_irq_mask &= ~bit;
/* Disable the interrupt. */
*(vulp)PYXIS_INT_MASK = mask;
wmb();
/* Ack PYXIS PCI interrupt. */
*(vulp)PYXIS_INT_REQ = bit;
mb();
/* Re-read to force both writes. */
*(vulp)PYXIS_INT_MASK;
}
static struct hw_interrupt_type pyxis_irq_type = {
.typename = "PYXIS",
.startup = pyxis_startup_irq,
.shutdown = pyxis_disable_irq,
.enable = pyxis_enable_irq,
.disable = pyxis_disable_irq,
.ack = pyxis_mask_and_ack_irq,
.end = pyxis_end_irq,
};
void
pyxis_device_interrupt(unsigned long vector, struct pt_regs *regs)
{
unsigned long pld;
unsigned int i;
/* Read the interrupt summary register of PYXIS */
pld = *(vulp)PYXIS_INT_REQ;
pld &= cached_irq_mask;
/*
* Now for every possible bit set, work through them and call
* the appropriate interrupt handler.
*/
while (pld) {
i = ffz(~pld);
pld &= pld - 1; /* clear least bit set */
if (i == 7)
isa_device_interrupt(vector, regs);
else
handle_irq(16+i, regs);
}
}
void __init
init_pyxis_irqs(unsigned long ignore_mask)
{
long i;
*(vulp)PYXIS_INT_MASK = 0; /* disable all */
*(vulp)PYXIS_INT_REQ = -1; /* flush all */
mb();
/* Send -INTA pulses to clear any pending interrupts ...*/
*(vuip) CIA_IACK_SC;
for (i = 16; i < 48; ++i) {
if ((ignore_mask >> i) & 1)
continue;
irq_desc[i].status = IRQ_DISABLED | IRQ_LEVEL;
irq_desc[i].chip = &pyxis_irq_type;
}
setup_irq(16+7, &isa_cascade_irqaction);
}