Rob Herring wrote:
From: Grant Likely <[email protected]>
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.
Completely untested.
[1] http://lkml.org/lkml/2005/11/21/221
Signed-off-by: Grant Likely <[email protected]>
Signed-off-by: Rob Herring <[email protected]>
---
The main complaint with the prior version was Michal's complaint about the
+1 / -1 conversion in every function. This is now solved with the use of
irq_data.hwirq to store the h/w irq numbers.
I also fixed some errors around nr_irq.
I have looked at your patch and fix some things.
Rob
arch/microblaze/include/asm/irq.h | 4 ++--
arch/microblaze/kernel/intc.c | 18 ++++++++++--------
arch/microblaze/kernel/irq.c | 10 ++++++----
3 files changed, 18 insertions(+), 14 deletions(-)
diff --git a/arch/microblaze/include/asm/irq.h
b/arch/microblaze/include/asm/irq.h
index cc54187..b07c179 100644
--- a/arch/microblaze/include/asm/irq.h
+++ b/arch/microblaze/include/asm/irq.h
@@ -9,7 +9,7 @@
#ifndef _ASM_MICROBLAZE_IRQ_H
#define _ASM_MICROBLAZE_IRQ_H
-#define NR_IRQS 32
+#define NR_IRQS (32 + 1) /* Add 1 to skip over IRQ0 */
#include <asm-generic/irq.h>
/* This type is the placeholder for a hardware interrupt number. It has to
@@ -20,7 +20,7 @@ typedef unsigned long irq_hw_number_t;
extern unsigned int nr_irq;
-#define NO_IRQ (-1)
+#define NO_IRQ 0
struct pt_regs;
extern void do_IRQ(struct pt_regs *regs);
diff --git a/arch/microblaze/kernel/intc.c b/arch/microblaze/kernel/intc.c
index eb41441..ed65aac 100644
--- a/arch/microblaze/kernel/intc.c
+++ b/arch/microblaze/kernel/intc.c
@@ -42,7 +42,7 @@ unsigned int nr_irq;
static void intc_enable_or_unmask(struct irq_data *d)
{
- unsigned long mask = 1 << d->irq;
+ unsigned long mask = 1 << d->hwirq;
pr_debug("enable_or_unmask: %d\n", d->irq);
out_be32(INTC_BASE + SIE, mask);
@@ -57,18 +57,18 @@ static void intc_enable_or_unmask(struct irq_data *d)
static void intc_disable_or_mask(struct irq_data *d)
{
pr_debug("disable: %d\n", d->irq);
- out_be32(INTC_BASE + CIE, 1 << d->irq);
+ out_be32(INTC_BASE + CIE, 1 << d->hwirq);
}
static void intc_ack(struct irq_data *d)
{
pr_debug("ack: %d\n", d->irq);
- out_be32(INTC_BASE + IAR, 1 << d->irq);
+ out_be32(INTC_BASE + IAR, 1 << d->hwirq);
}
static void intc_mask_ack(struct irq_data *d)
{
- unsigned long mask = 1 << d->irq;
+ unsigned long mask = 1 << d->hwirq;
pr_debug("disable_and_ack: %d\n", d->irq);
out_be32(INTC_BASE + CIE, mask);
out_be32(INTC_BASE + IAR, mask);
@@ -90,8 +90,11 @@ unsigned int get_irq(struct pt_regs *regs)
* NOTE: This function is the one that needs to be improved in
* order to handle multiple interrupt controllers. It currently
* is hardcoded to check for interrupts only on the first INTC.
+ *
+ * Linux IRQ# is currently offset by one to map to the hardware
+ * irq number. So hardware IRQ0 maps to Linux irq 1.
*/
- irq = in_be32(INTC_BASE + IVR);
+ irq = in_be32(INTC_BASE + IVR) + 1;
pr_debug("get_irq: %d\n", irq);
return irq;
@@ -134,8 +137,6 @@ void __init init_IRQ(void)
intr_type =
be32_to_cpup(of_get_property(intc,
"xlnx,kind-of-intr", NULL));
- if (intr_type > (u32)((1ULL << nr_irq) - 1))
- printk(KERN_INFO " ERROR: Mismatch in kind-of-intr param\n");
This is necessary to keep it because some older versions had a bug.
It is just checking mechanism and not NO_IRQ related change.
#ifdef CONFIG_SELFMOD_INTC
selfmod_function((int *) arr_func, intc_baseaddr);
@@ -155,7 +156,7 @@ void __init init_IRQ(void)
/* Turn on the Master Enable. */
out_be32(intc_baseaddr + MER, MER_HIE | MER_ME);
- for (i = 0; i < nr_irq; ++i) {
+ for (i = 1; i < nr_irq; ++i) {
if (intr_type & (0x00000001 << i)) {
intr_type should be called intr_mask because it is used as mask.
Which means that this should be (i - 1) because of shift.
irq_set_chip_and_handler_name(i, &intc_dev,
handle_edge_irq, "edge");
@@ -165,5 +166,6 @@ void __init init_IRQ(void)
handle_level_irq, "level");
irq_set_status_flags(i, IRQ_LEVEL);
}
+ irq_get_irq_data(i)->hwirq = i - 1;
}
}
diff --git a/arch/microblaze/kernel/irq.c b/arch/microblaze/kernel/irq.c
index e5d63a8..ac1b463 100644
--- a/arch/microblaze/kernel/irq.c
+++ b/arch/microblaze/kernel/irq.c
@@ -33,11 +33,11 @@ void __irq_entry do_IRQ(struct pt_regs *regs)
irq_enter();
irq = get_irq(regs);
next_irq:
- BUG_ON(irq == -1U);
+ BUG_ON(!irq);
generic_handle_irq(irq);
irq = get_irq(regs);
- if (irq != -1U) {
+ if (irq) {
pr_debug("next irq: %d\n", irq);
++concurrent_irq;
goto next_irq;
@@ -52,13 +52,15 @@ next_irq:
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;
+ return hwirq + 1;
}
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];
+ /* Hardware irq is mapped to Linux IRQ# by a 1 offset. Linux irq
+ * 0 means no IRQ. */
+ return intspec[0] + 1;
}
EXPORT_SYMBOL_GPL(irq_create_of_mapping);
I have created 5 patches to fix interrupt and timer code with changes to get
NO_IRQ
to work.
I don't like one thing which is magic + 1 offset on some places with the same
comment
which explain that it is because of NO_IRQ. I have created macros to solve this
(IRQ_SW_OFFSET and IRQ_OFFSET). Please comment it.
Thanks,
Michal
--
Michal Simek, Ing. (M.Eng)
w: www.monstr.eu p: +42-0-721842854
Maintainer of Linux kernel 2.6 Microblaze Linux - http://www.monstr.eu/fdt/
Microblaze U-BOOT custodian
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