[PATCH] irq_domain/microblaze: Convert microblaze to use irq_domains

[PATCH] irq_domain/microblaze: Convert microblaze to use irq_domains

[Grant Likely]

***totally untested.  Don't apply yet***

Michal, I leave it to you to test this patch.  I've turned on SPARSE_IRQ, but
you may decide that isn't valuable.  I've compile tested it, but that's
about it (in fact, I had to hack head.S to get it to build because I don't have
an up-to-date compiler for microblaze.  It fails on an unknown opcode 'lwr')

This builds on top of my irq_domain tree:
git://git.secretlab.ca/git/linux-2.6 irqdomain/next

Signed-off-by: Grant Likely <grant.likely-s3s/WqlpOiPyB63q8FvJNQ@public.gmane.org>
Cc: Michal Simek <monstr-pSz03upnqPeHXe+LvDLADg@public.gmane.org>
Cc: Rob Herring <rob.herring-bsGFqQB8/DxBDgjK7y7TUQ@public.gmane.org>
Cc: John Williams <john.williams-g5w7nrANp4BDPfheJLI6IQ@public.gmane.org>
Cc: John Linn <john.linn-gjFFaj9aHVfQT0dZR+AlfA@public.gmane.org>
---
 arch/microblaze/Kconfig               |    2 +
 arch/microblaze/include/asm/hardirq.h |    2 +-
 arch/microblaze/include/asm/irq.h     |   41 +----------------------
 arch/microblaze/kernel/intc.c         |   58 +++++++++++++++++++-------------
 arch/microblaze/kernel/irq.c          |   22 ++-----------
 5 files changed, 41 insertions(+), 84 deletions(-)

diff --git a/arch/microblaze/Kconfig b/arch/microblaze/Kconfig
index 74f23a4..1e6f59c 100644
--- a/arch/microblaze/Kconfig
+++ b/arch/microblaze/Kconfig
@@ -14,6 +14,8 @@ config MICROBLAZE
 	select TRACING_SUPPORT
 	select OF
 	select OF_EARLY_FLATTREE
+	select IRQ_DOMAIN
+	select SPARSE_IRQ
 	select HAVE_GENERIC_HARDIRQS
 	select GENERIC_IRQ_PROBE
 	select GENERIC_IRQ_SHOW
diff --git a/arch/microblaze/include/asm/hardirq.h b/arch/microblaze/include/asm/hardirq.h
index cd1ac9a..a265aa0 100644
--- a/arch/microblaze/include/asm/hardirq.h
+++ b/arch/microblaze/include/asm/hardirq.h
@@ -10,7 +10,7 @@
 #define _ASM_MICROBLAZE_HARDIRQ_H
 
 /* should be defined in each interrupt controller driver */
-extern unsigned int get_irq(struct pt_regs *regs);
+extern unsigned int get_irq(void);
 
 #include <asm-generic/hardirq.h>
 
diff --git a/arch/microblaze/include/asm/irq.h b/arch/microblaze/include/asm/irq.h
index 7798ad1..5ddbf69 100644
--- a/arch/microblaze/include/asm/irq.h
+++ b/arch/microblaze/include/asm/irq.h
@@ -9,49 +9,10 @@
 #ifndef _ASM_MICROBLAZE_IRQ_H
 #define _ASM_MICROBLAZE_IRQ_H
 
-
-/*
- * Linux IRQ# is currently offset by one to map to the hardware
- * irq number. So hardware IRQ0 maps to Linux irq 1.
- */
-#define NO_IRQ_OFFSET	1
-#define IRQ_OFFSET	NO_IRQ_OFFSET
-#define NR_IRQS		(32 + IRQ_OFFSET)
+#define NR_IRQS		(64)
 #include <asm-generic/irq.h>
 
-/* This type is the placeholder for a hardware interrupt number. It has to
- * be big enough to enclose whatever representation is used by a given
- * platform.
- */
-typedef unsigned long irq_hw_number_t;
-
-extern unsigned int nr_irq;
-
 struct pt_regs;
 extern void do_IRQ(struct pt_regs *regs);
 
-/** FIXME - not implement
- * irq_dispose_mapping - Unmap an interrupt
- * @virq: linux virq number of the interrupt to unmap
- */
-static inline void irq_dispose_mapping(unsigned int virq)
-{
-	return;
-}
-
-struct irq_domain;
-
-/**
- * irq_create_mapping - Map a hardware interrupt into linux virq space
- * @host: host owning this hardware interrupt or NULL for default host
- * @hwirq: hardware irq number in that host space
- *
- * Only one mapping per hardware interrupt is permitted. Returns a linux
- * virq number.
- * If the sense/trigger is to be specified, set_irq_type() should be called
- * on the number returned from that call.
- */
-extern unsigned int irq_create_mapping(struct irq_domain *host,
-					irq_hw_number_t hwirq);
-
 #endif /* _ASM_MICROBLAZE_IRQ_H */
diff --git a/arch/microblaze/kernel/intc.c b/arch/microblaze/kernel/intc.c
index 44b177e..cc1f6eb 100644
--- a/arch/microblaze/kernel/intc.c
+++ b/arch/microblaze/kernel/intc.c
@@ -9,6 +9,7 @@
  */
 
 #include <linux/init.h>
+#include <linux/irqdomain.h>
 #include <linux/irq.h>
 #include <asm/page.h>
 #include <linux/io.h>
@@ -25,8 +26,6 @@ static unsigned int intc_baseaddr;
 #define INTC_BASE	intc_baseaddr
 #endif
 
-unsigned int nr_irq;
-
 /* No one else should require these constants, so define them locally here. */
 #define ISR 0x00			/* Interrupt Status Register */
 #define IPR 0x04			/* Interrupt Pending Register */
@@ -84,24 +83,43 @@ static struct irq_chip intc_dev = {
 	.irq_mask_ack = intc_mask_ack,
 };
 
-unsigned int get_irq(struct pt_regs *regs)
+static struct irq_domain *root_domain;
+
+unsigned int get_irq(void)
 {
-	int irq;
+	unsigned int hwirq, irq;
 
-	/*
-	 * 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.
-	 */
-	irq = in_be32(INTC_BASE + IVR) + NO_IRQ_OFFSET;
-	pr_debug("get_irq: %d\n", irq);
+	hwirq = in_be32(INTC_BASE + IVR);
+	irq = irq_find_mapping(root_domain, in_be32(INTC_BASE + IVR));
+	pr_debug("get_irq: hwirq=%d, irq=%d\n", hwirq, irq);
 
 	return irq;
 }
 
+int xintc_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hw)
+{
+	u32 intr_mask = (u32)d->host_data;
+
+	if (intr_mask & (1 << hw)) {
+		irq_set_chip_and_handler_name(irq, &intc_dev,
+						handle_edge_irq, "edge");
+		irq_clear_status_flags(irq, IRQ_LEVEL);
+	} else {
+		irq_set_chip_and_handler_name(irq, &intc_dev,
+						handle_level_irq, "level");
+		irq_set_status_flags(irq, IRQ_LEVEL);
+	}
+	return 0;
+}
+
+static const struct irq_domain_ops xintc_irq_domain_ops = {
+	.xlate = irq_domain_xlate_onetwocell,
+	.map = xintc_map,
+};
+
 void __init init_IRQ(void)
 {
-	u32 i, intr_mask;
+	u32 nr_irq, intr_mask;
 	struct device_node *intc = NULL;
 #ifdef CONFIG_SELFMOD_INTC
 	unsigned int intc_baseaddr = 0;
@@ -146,16 +164,8 @@ void __init init_IRQ(void)
 	/* Turn on the Master Enable. */
 	out_be32(intc_baseaddr + MER, MER_HIE | MER_ME);
 
-	for (i = IRQ_OFFSET; i < (nr_irq + IRQ_OFFSET); ++i) {
-		if (intr_mask & (0x00000001 << (i - IRQ_OFFSET))) {
-			irq_set_chip_and_handler_name(i, &intc_dev,
-				handle_edge_irq, "edge");
-			irq_clear_status_flags(i, IRQ_LEVEL);
-		} else {
-			irq_set_chip_and_handler_name(i, &intc_dev,
-				handle_level_irq, "level");
-			irq_set_status_flags(i, IRQ_LEVEL);
-		}
-		irq_get_irq_data(i)->hwirq = i - IRQ_OFFSET;
-	}
+	/* Yeah, okay, casting the intr_mask to a void* is butt-ugly, but I'm
+	 * lazy and Michal can clean it up to something nicer when he tests
+	 * and commits this patch.  ~~gcl */
+	root_domain = irq_domain_add_linear(intc, nr_irq, &xintc_irq_domain_ops, (void*)intr_mask);
 }
diff --git a/arch/microblaze/kernel/irq.c b/arch/microblaze/kernel/irq.c
index 3f613df..91ce0e5 100644
--- a/arch/microblaze/kernel/irq.c
+++ b/arch/microblaze/kernel/irq.c
@@ -31,13 +31,12 @@ void __irq_entry do_IRQ(struct pt_regs *regs)
 	trace_hardirqs_off();
 
 	irq_enter();
-	irq = get_irq(regs);
+	irq = get_irq();
 next_irq:
 	BUG_ON(!irq);
-	/* Substract 1 because of get_irq */
-	generic_handle_irq(irq + IRQ_OFFSET - NO_IRQ_OFFSET);
+	generic_handle_irq(irq);
 
-	irq = get_irq(regs);
+	irq = get_irq();
 	if (irq) {
 		pr_debug("next irq: %d\n", irq);
 		++concurrent_irq;
@@ -48,18 +47,3 @@ next_irq:
 	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_domain *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);
-- 
1.7.5.4

Re: [PATCH] irq_domain/microblaze: Convert microblaze to use irq_domains

[Michal Simek]

Grant Likely wrote:
> ***totally untested.  Don't apply yet***
> 
> Michal, I leave it to you to test this patch.  I've turned on SPARSE_IRQ, but
> you may decide that isn't valuable.  I've compile tested it, but that's
> about it (in fact, I had to hack head.S to get it to build because I don't have
> an up-to-date compiler for microblaze.  It fails on an unknown opcode 'lwr')
> 
> This builds on top of my irq_domain tree:
> git://git.secretlab.ca/git/linux-2.6 irqdomain/next
> 
> Signed-off-by: Grant Likely <grant.likely-s3s/WqlpOiPyB63q8FvJNQ@public.gmane.org>
> Cc: Michal Simek <monstr-pSz03upnqPeHXe+LvDLADg@public.gmane.org>
> Cc: Rob Herring <rob.herring-bsGFqQB8/DxBDgjK7y7TUQ@public.gmane.org>
> Cc: John Williams <john.williams-g5w7nrANp4BDPfheJLI6IQ@public.gmane.org>
> Cc: John Linn <john.linn-gjFFaj9aHVfQT0dZR+AlfA@public.gmane.org>
> ---
>  arch/microblaze/Kconfig               |    2 +
>  arch/microblaze/include/asm/hardirq.h |    2 +-
>  arch/microblaze/include/asm/irq.h     |   41 +----------------------
>  arch/microblaze/kernel/intc.c         |   58 +++++++++++++++++++-------------
>  arch/microblaze/kernel/irq.c          |   22 ++-----------
>  5 files changed, 41 insertions(+), 84 deletions(-)

I will look at it and let you know.

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

Re: [PATCH] irq_domain/microblaze: Convert microblaze to use irq_domains

[Michal Simek]

Hi Grant,

Grant Likely wrote:
> ***totally untested.  Don't apply yet***
> 
> Michal, I leave it to you to test this patch.  I've turned on SPARSE_IRQ, but
> you may decide that isn't valuable.  I've compile tested it, but that's
> about it (in fact, I had to hack head.S to get it to build because I don't have
> an up-to-date compiler for microblaze.  It fails on an unknown opcode 'lwr')
> 

I have looked at it and I there is problem with virq allocation in irq_create_mapping
which calles irq_alloc_desc(0) and then __irq_alloc_descs(-1, 0, 1, node, THIS_MODULE)
where bitmap_find_next_zero_area returns 0 (start = 0) which is passed to alloc_descs
which just return it.
It doesn't matter if SPARSE_IRQ is enabled or not.
Error log is below.

Can you give me hint how to fix it and what expected values are?

Thanks,
Michal

Error log:

NR_IRQS:64
XPS intc #0 at 0xc8000000, num_irq=6, edge=0x0
irq: Allocated domain of type 2 @0xc7802760
irq: irq_create_mapping(0xc7802760, 0x2)
irq: -> using domain @c7802760
irq: -> virq allocation failed
XPS timer #0 at 0xc8002000, irq=0



-- 
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

Re: [PATCH] irq_domain/microblaze: Convert microblaze to use irq_domains

[Grant Likely]

On Mon, Jan 30, 2012 at 12:42:26PM +0100, Michal Simek wrote:
> Hi Grant,
> 
> Grant Likely wrote:
> >***totally untested.  Don't apply yet***
> >
> >Michal, I leave it to you to test this patch.  I've turned on SPARSE_IRQ, but
> >you may decide that isn't valuable.  I've compile tested it, but that's
> >about it (in fact, I had to hack head.S to get it to build because I don't have
> >an up-to-date compiler for microblaze.  It fails on an unknown opcode 'lwr')
> >
> 
> I have looked at it and I there is problem with virq allocation in irq_create_mapping
> which calles irq_alloc_desc(0) and then __irq_alloc_descs(-1, 0, 1, node, THIS_MODULE)
> where bitmap_find_next_zero_area returns 0 (start = 0) which is passed to alloc_descs
> which just return it.
> It doesn't matter if SPARSE_IRQ is enabled or not.
> Error log is below.
> 
> Can you give me hint how to fix it and what expected values are?

irq0 is getting allocated when it shouldn't be.  The fix is to change the
calls in irqdomain.c from irq_alloc_desc(0) to irq_alloc_desc_from(1, 0).

I've got the fix in my tree and I'm pushing it out to the following branch
in a few minutes:

git://git.secretlab.ca/git/linux-2.6 irqdomain/next

g.

Re: [PATCH] irq_domain/microblaze: Convert microblaze to use irq_domains

[Michal Simek]

Grant Likely wrote:
> On Mon, Jan 30, 2012 at 12:42:26PM +0100, Michal Simek wrote:
>> Hi Grant,
>>
>> Grant Likely wrote:
>>> ***totally untested.  Don't apply yet***
>>>
>>> Michal, I leave it to you to test this patch.  I've turned on SPARSE_IRQ, but
>>> you may decide that isn't valuable.  I've compile tested it, but that's
>>> about it (in fact, I had to hack head.S to get it to build because I don't have
>>> an up-to-date compiler for microblaze.  It fails on an unknown opcode 'lwr')
>>>
>> I have looked at it and I there is problem with virq allocation in irq_create_mapping
>> which calles irq_alloc_desc(0) and then __irq_alloc_descs(-1, 0, 1, node, THIS_MODULE)
>> where bitmap_find_next_zero_area returns 0 (start = 0) which is passed to alloc_descs
>> which just return it.
>> It doesn't matter if SPARSE_IRQ is enabled or not.
>> Error log is below.
>>
>> Can you give me hint how to fix it and what expected values are?
> 
> irq0 is getting allocated when it shouldn't be.  The fix is to change the
> calls in irqdomain.c from irq_alloc_desc(0) to irq_alloc_desc_from(1, 0).
> 
> I've got the fix in my tree and I'm pushing it out to the following branch
> in a few minutes:
> 
> git://git.secretlab.ca/git/linux-2.6 irqdomain/next

ok. I have tested your new branch I have fixed and tested microblaze patch.
I will disable SPARSE_IRQ because nothing bring to us. From my quick look it will
just additional code.

The last two thing before I send updated patch is why did you choosed NR_IRQ to 64.
We doesn't support cascades or any complicated IRQ subsystem and intc can provide just 32 lines.

And can you see any strong reason to keep get_irq in hardirq.h. I would move it to irq.h.

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