linux/arch/microblaze/kernel/irq.c
Michal Simek 6c7a2676f5 microblaze: Change NO_IRQ to 0
As has been discussed many times[1], Using NO_IRQ set to anything other
than 0 is bug waiting to happen since many drivers follow the pattern
"if (!irq)" for testing whether or not an irq has been set.

This patch changes the Microblaze NO_IRQ setting from -1 to 0 to bring
it in line with most of the rest of the kernel.  It also prepares for
Microblaze eventually supporting multiple interrupt controllers by
breaking the assumption that hwirq# == Linux IRQ#.  The Linux IRQ
number is just a cookie with no guarantee of a direct relationship
with the hardware irq arrangement.

At this point, Microblaze interrupt handling only supports only one
instance of one kind of interrupt controller (xilinx_intc).  This change
shouldn't affect any architecture code outside of the interrupt
controller driver and the irq_of mapping.

Updated to 3.2 and to use irq_data.hwirq by Rob Herring.
Tested and fixed by Michal Simek.

[1] http://lkml.org/lkml/2005/11/21/221

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Michal Simek <monstr@monstr.eu>
2012-01-05 08:29:13 +01:00

66 lines
1.6 KiB
C

/*
* Copyright (C) 2007-2009 Michal Simek <monstr@monstr.eu>
* Copyright (C) 2007-2009 PetaLogix
* Copyright (C) 2006 Atmark Techno, Inc.
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#include <linux/init.h>
#include <linux/ftrace.h>
#include <linux/kernel.h>
#include <linux/hardirq.h>
#include <linux/interrupt.h>
#include <linux/irqflags.h>
#include <linux/seq_file.h>
#include <linux/kernel_stat.h>
#include <linux/irq.h>
#include <linux/of_irq.h>
#include <linux/export.h>
#include <asm/prom.h>
static u32 concurrent_irq;
void __irq_entry do_IRQ(struct pt_regs *regs)
{
unsigned int irq;
struct pt_regs *old_regs = set_irq_regs(regs);
trace_hardirqs_off();
irq_enter();
irq = get_irq(regs);
next_irq:
BUG_ON(!irq);
/* Substract 1 because of get_irq */
generic_handle_irq(irq + IRQ_OFFSET - NO_IRQ_OFFSET);
irq = get_irq(regs);
if (irq) {
pr_debug("next irq: %d\n", irq);
++concurrent_irq;
goto next_irq;
}
irq_exit();
set_irq_regs(old_regs);
trace_hardirqs_on();
}
/* MS: There is no any advance mapping mechanism. We are using simple 32bit
intc without any cascades or any connection that's why mapping is 1:1 */
unsigned int irq_create_mapping(struct irq_host *host, irq_hw_number_t hwirq)
{
return hwirq + IRQ_OFFSET;
}
EXPORT_SYMBOL_GPL(irq_create_mapping);
unsigned int irq_create_of_mapping(struct device_node *controller,
const u32 *intspec, unsigned int intsize)
{
return intspec[0] + IRQ_OFFSET;
}
EXPORT_SYMBOL_GPL(irq_create_of_mapping);