Re: [PATCHv2 02/10] ARM: vic: MULTI_IRQ_HANDLER handler

[Jamie Iles <jamie-wmLquQDDieKakBO8gow8eQ@public.gmane.org>]

On Thu, Sep 29, 2011 at 08:55:08AM +0200, Linus Walleij wrote:
> On Wed, Sep 28, 2011 at 10:39 PM, Grant Likely
> <grant.likely-s3s/WqlpOiPyB63q8FvJNQ@public.gmane.org> wrote:
> 
> > Why isn't it simply written this way:
> >
> >        stat = readl_relaxed(vic->base + VIC_IRQ_STATUS);
> >        while (stat) {
> >                irq = fls(stat) - 1;
> >                handle_IRQ(irq_domain_to_irq(&vic->domain, irq), regs);
> >                stat &= ~(1 << irq);
> >        }
> 
> That is indeed closer to the assembly loop most platforms have
> implemented.
> 
> Jamie can you test this approach? And also use ffs() insteadof
> fls()...

OK, here it is (and it works)!  That does make it a lot simpler, thanks 
guys!  I've updated the vic-dt branch in my repo too.

Jamie

8<------
From: Jamie Iles <jamie-wmLquQDDieKakBO8gow8eQ@public.gmane.org>
Subject: [PATCHv3] ARM: vic: MULTI_IRQ_HANDLER handler

Add a handler for the VIC that is suitable for MULTI_IRQ_HANDLER
platforms.  This can replace the ASM entry macros for platforms that use
the VIC.

v3:	- simplify irq handling loop as suggested by Grant
	- service interrupts from msb->lsb order
v2:	- allow the handler be used for !CONFIG_OF
	- use irq_domain_to_irq()

Cc: Rob Herring <robherring2-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Cc: Grant Likely <grant.likely-s3s/WqlpOiPyB63q8FvJNQ@public.gmane.org>
Signed-off-by: Jamie Iles <jamie-wmLquQDDieKakBO8gow8eQ@public.gmane.org>
---
 arch/arm/common/vic.c               |   22 ++++++++++++++++++++++
 arch/arm/include/asm/hardware/vic.h |    4 ++++
 2 files changed, 26 insertions(+), 0 deletions(-)

diff --git a/arch/arm/common/vic.c b/arch/arm/common/vic.c
index 3f9c8f2..b22b83d 100644
--- a/arch/arm/common/vic.c
+++ b/arch/arm/common/vic.c
@@ -427,3 +427,25 @@ int __init vic_of_init(struct device_node *node, struct device_node *parent)
 	return -EIO;
 }
 #endif /* CONFIG OF */
+
+#ifdef CONFIG_MULTI_IRQ_HANDLER
+static void vic_single_handle_irq(struct vic_device *vic, struct pt_regs *regs)
+{
+	u32 stat, irq;
+
+	stat = readl_relaxed(vic->base + VIC_IRQ_STATUS);
+	while (stat) {
+		irq = ffs(stat) - 1;
+		handle_IRQ(irq_domain_to_irq(&vic->domain, irq), regs);
+		stat &= ~(1 << irq);
+	}
+}
+
+asmlinkage void __exception_irq_entry vic_handle_irq(struct pt_regs *regs)
+{
+	int i;
+
+	for (i = 0; i < vic_id; ++i)
+		vic_single_handle_irq(&vic_devices[i], regs);
+}
+#endif /* CONFIG_MULTI_IRQ_HANDLER */
diff --git a/arch/arm/include/asm/hardware/vic.h b/arch/arm/include/asm/hardware/vic.h
index 0135215..c02fd6f 100644
--- a/arch/arm/include/asm/hardware/vic.h
+++ b/arch/arm/include/asm/hardware/vic.h
@@ -45,11 +45,15 @@
 #include <linux/types.h>
 
 struct device_node;
+struct pt_regs;
+
 void vic_init(void __iomem *base, unsigned int irq_start, u32 vic_sources, u32 resume_sources);
 
 #ifdef CONFIG_OF
 int vic_of_init(struct device_node *node, struct device_node *parent);
 #endif /* CONFIG_OF */
 
+void vic_handle_irq(struct pt_regs *regs);
+
 #endif /* __ASSEMBLY__ */
 #endif
-- 
1.7.4.1