[PATCH v9 16/21] irqchip: Add GICv2 specific ACPI boot support

On Thursday, March 05, 2015 11:53:22 AM Catalin Marinas wrote:

On Wed, Mar 04, 2015 at 11:50:36PM +0100, Rafael J. Wysocki wrote:

quoted

On Wednesday, February 25, 2015 04:39:56 PM Hanjun Guo wrote:

[cut]

quoted

quoted

diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index c03d8d1..e27117a 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h

@@ -557,6 +557,20 @@ static inline int acpi_device_modalias(struct device *dev,
 
 #endif	/* !CONFIG_ACPI */
 
+#if defined(CONFIG_ACPI) && defined(CONFIG_ARM64)
+static inline void acpi_irq_init(void)
+{
+	/*
+	 * Hardcode ACPI IRQ chip initialization to GICv2 for now.
+	 * Proper irqchip infrastructure will be implemented along with
+	 * incoming  GICv2m|GICv3|ITS bits.
+	 */
+	acpi_gic_init();
+}
+#else
+static inline void acpi_irq_init(void) { }
+#endif

I don't want this in a common header.

I don't like it either. What about adding it to a new header,
linux/acpi_irq.h just for the dummy acpi_irq_init()? This would be
similar to the DT equivalent, of_irq_init() in linux/of_irq.h and at
some point it will gain more macros for declaring interrupt controllers
in the ACPI context.

What we objected to previously was calling acpi_gic_init() directly from
the core irqchip_init() and asked for something similar to the more
generic of_irq_init(). The arm64-specific patch above is clearly a
temporary hack until full support for multiple interrupt controllers is
added (we asked for this several times in the past, but the ARM ACPI
guys thought it's too much hassle ;). I don't fully get it since one of
the platforms they target needs GICv2m support anyway).

Anyway, if we are to keep the temporary hack, I think we could define
something like below (possibly in a new linux/acpi_irq.h which includes
asm/irq.h):

#ifndef acpi_irq_init
static inline void acpi_irq_init(void)
{
}
#endif

And in the arm64 asm/irq.h:

static inline void acpi_irq_init(void)
{
	/*
	 * Hardcode ACPI IRQ chip initialization to GICv2 for now.
	 * Proper irqchip infrastructure will be implemented along with
	 * incoming  GICv2m|GICv3|ITS bits.
	 */
	acpi_gic_init();
}
#define acpi_irq_init acpi_irq_init

When the new infrastructure is in place, we can get rid of the #ifndef
and arm64-specific acpi_irq_init().

Well, that sounds much better than the original patch.

Rafael