[RFC,PATCHv1,1/2] ARM: socfpga: initial support for Altera's SOCFPGA platform.

Commit Message

Pavel Machek July 1, 2012, 6:41 p.m. UTC

On Sat 2012-06-30 21:04:37, Arnd Bergmann wrote:
> On Wednesday 27 June 2012, Thomas Petazzoni wrote:
> > > > > +#define NR_IRQS                  512
> > > > 
> > > > You should be looking at using SPARSE_IRQ to avoid having a maximum
> > > > number of irqs. See for example mach-highbank/.
> > > 
> > > Is maximum number of interrupts a problem? 512 does not seem
> > > excessive.
> > 
> > Regardless of the value of NR_IRQS, there is apparently a trend to use
> > SPARSE_IRQ anyway. However, I am not at the best place to explain why
> > SPARSE_IRQ is now considered the right thing to use.
> 
> The main reason for me is to get rid of a hardcoded NR_IRQS constant,
> whihc is a blocker for multiplatform kernels. New platforms should
> do all they can to allow being built together with other platforms
> in the same kernel. While we're not there yet, doing sparse irq
> is an important step in the right direction and should not be hard
> to do for new code.

Something as easy as this? But it does not seem to boot here :-(.

								Pavel

Comments

Arnd Bergmann July 2, 2012, 4:52 p.m. UTC | #1

On Sunday 01 July 2012, Pavel Machek wrote:
> @@ -133,6 +134,11 @@ static void socfpga_cyclone5_restart(char mode, const char *cmd)
>  
>  static void __init socfpga_cyclone5_init(void)
>  {
> +       int i;
> +       for (i = 0; i < 512; i++) {
> +               dynamic_irq_init(i);
> +       }
> +
>  #ifdef CONFIG_CACHE_L2X0
>         /* 8-way, 64K/way, evmon/parity/share */
>         l2x0_of_init(0x00760000, 0xfe000fff);
> 

This looks wrong, I think what you should do instead is
to call irq_domain_add_legacy() for each controller you
register as the first step, and then try to convert the
controllers to use irq_domain_add_linear() as the second
step. See also Documentation/IRQ-domain.txt.

	Arnd

Patch

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index b1578e1..d203253 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -263,6 +263,7 @@  config ARCH_SOCFPGA
 	select GPIO_PL061 if GPIOLIB
 	select NEED_MACH_MEMORY_H
 	select USE_OF
+	select SPARSE_IRQ
 	help
 	  This enables support for Altera SOCFPGA Cyclone V platform
 
diff --git a/arch/arm/mach-socfpga/include/mach/irqs.h b/arch/arm/mach-socfpga/include/mach/irqs.h
index da50124..565ca59 100644
--- a/arch/arm/mach-socfpga/include/mach/irqs.h
+++ b/arch/arm/mach-socfpga/include/mach/irqs.h
@@ -27,8 +27,6 @@ 
 #define IRQ_SOCFPGA_CLK_MAN            (IRQ_SOCFPGA_GIC_START + 173)   /* Clock manager */
 
 
-#define NR_IRQS			512
-
 #define MAX_GIC_NR		1
 
 #endif	/* __MACH_IRQS_H */
diff --git a/arch/arm/mach-socfpga/socfpga_cyclone5.c b/arch/arm/mach-socfpga/socfpga_cyclone5.c
index f6498cc..674bac3 100644
--- a/arch/arm/mach-socfpga/socfpga_cyclone5.c
+++ b/arch/arm/mach-socfpga/socfpga_cyclone5.c
@@ -24,6 +24,7 @@ 
 #include <mach/socfpga-timer.h>
 #include <mach/dw_apb_timer.h>
 #include <mach/socfpga_cyclone5.h>
+#include <mach/irqs.h>
 #include <asm/mach-types.h>
 #include <asm/mach/arch.h>
 #include <asm/mach/map.h>
@@ -133,6 +134,11 @@  static void socfpga_cyclone5_restart(char mode, const char *cmd)
 
 static void __init socfpga_cyclone5_init(void)
 {
+	int i;
+	for (i = 0; i < 512; i++) {
+		dynamic_irq_init(i);
+	}
+
 #ifdef CONFIG_CACHE_L2X0
 	/* 8-way, 64K/way, evmon/parity/share */
 	l2x0_of_init(0x00760000, 0xfe000fff);