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

On Thu, Sep 29, 2011 at 08:55:08AM +0200, Linus Walleij wrote:

On Wed, Sep 28, 2011 at 10:39 PM, Grant Likely
[off-list ref] wrote:

quoted

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 <redacted>
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 <redacted>
Cc: Grant Likely <redacted>
Signed-off-by: Jamie Iles <redacted>
---
 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