[PATCH v3] ARM: OMAP3: Check for L2 cache enabled

[PATCH v3] ARM: OMAP3: Check for L2 cache enabled

[Dirk Behme]

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Enabling L2 cache of Cortex-A8 based OMAP3 has to be done by 
bootloader. Check if this is done and warn if not.

Signed-off-by: Dirk Behme <dirk.behme@gmail.com>

----

Changes in v3: Remove braces. Thanks to Felipe for review!

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Index: linux-beagle/arch/arm/mach-omap2/id.c
===================================================================
--- linux-beagle.orig/arch/arm/mach-omap2/id.c
+++ linux-beagle/arch/arm/mach-omap2/id.c
@@ -267,3 +267,25 @@ void __init omap2_check_revision(void)
 
 }
 
+#ifdef CONFIG_ARCH_OMAP3
+/*
+ * OMAP3 has L2 cache which has to be enabled by bootloader.
+ */
+static int __init omap3_check_l2cache(void)
+{
+	u32 val;
+
+	/* Get CP15 AUX register, bit 1 enabled indicates L2 cache is on */
+	asm volatile("mrc p15, 0, %0, c1, c0, 1":"=r" (val));
+
+	if ((val & 0x2) == 0)
+		printk(KERN_WARNING "Warning: L2 cache not enabled. Check "
+		       "your bootloader. L2 off results in performance loss\n");
+	else
+		pr_info("OMAP3 L2 cache enabled\n");
+
+	return 0;
+}
+
+arch_initcall(omap3_check_l2cache);
+#endif /* CONFIG_ARCH_OMAP3 */

Re: [PATCH v3] ARM: OMAP3: Check for L2 cache enabled

[Felipe Balbi]

On Sun, May 11, 2008 at 08:12:48AM +0200, Dirk Behme wrote:
>
> Enabling L2 cache of Cortex-A8 based OMAP3 has to be done by bootloader. 
> Check if this is done and warn if not.
>
> Signed-off-by: Dirk Behme <dirk.behme@gmail.com>
Acked-by: Felipe Balbi <felipe.balbi@nokia.com>
>
> ----
>
> Changes in v3: Remove braces. Thanks to Felipe for review!

> Index: linux-beagle/arch/arm/mach-omap2/id.c
> ===================================================================
> --- linux-beagle.orig/arch/arm/mach-omap2/id.c
> +++ linux-beagle/arch/arm/mach-omap2/id.c
> @@ -267,3 +267,25 @@ void __init omap2_check_revision(void)
>  
>  }
>  
> +#ifdef CONFIG_ARCH_OMAP3
> +/*
> + * OMAP3 has L2 cache which has to be enabled by bootloader.
> + */
> +static int __init omap3_check_l2cache(void)
> +{
> +	u32 val;
> +
> +	/* Get CP15 AUX register, bit 1 enabled indicates L2 cache is on */
> +	asm volatile("mrc p15, 0, %0, c1, c0, 1":"=r" (val));
> +
> +	if ((val & 0x2) == 0)
> +		printk(KERN_WARNING "Warning: L2 cache not enabled. Check "
> +		       "your bootloader. L2 off results in performance loss\n");
> +	else
> +		pr_info("OMAP3 L2 cache enabled\n");
> +
> +	return 0;
> +}
> +
> +arch_initcall(omap3_check_l2cache);
> +#endif /* CONFIG_ARCH_OMAP3 */


-- 
Best Regards,

Felipe Balbi
me@felipebalbi.com
http://blog.felipebalbi.com

Re: [PATCH v3] ARM: OMAP3: Check for L2 cache enabled

[Tony Lindgren]

* Felipe Balbi <me@felipebalbi.com> [080511 01:43]:
> On Sun, May 11, 2008 at 08:12:48AM +0200, Dirk Behme wrote:
> >
> > Enabling L2 cache of Cortex-A8 based OMAP3 has to be done by bootloader. 
> > Check if this is done and warn if not.
> >
> > Signed-off-by: Dirk Behme <dirk.behme@gmail.com>
> Acked-by: Felipe Balbi <felipe.balbi@nokia.com>

Pushing today.

Tony

> >
> > ----
> >
> > Changes in v3: Remove braces. Thanks to Felipe for review!
> 
> > Index: linux-beagle/arch/arm/mach-omap2/id.c
> > ===================================================================
> > --- linux-beagle.orig/arch/arm/mach-omap2/id.c
> > +++ linux-beagle/arch/arm/mach-omap2/id.c
> > @@ -267,3 +267,25 @@ void __init omap2_check_revision(void)
> >  
> >  }
> >  
> > +#ifdef CONFIG_ARCH_OMAP3
> > +/*
> > + * OMAP3 has L2 cache which has to be enabled by bootloader.
> > + */
> > +static int __init omap3_check_l2cache(void)
> > +{
> > +	u32 val;
> > +
> > +	/* Get CP15 AUX register, bit 1 enabled indicates L2 cache is on */
> > +	asm volatile("mrc p15, 0, %0, c1, c0, 1":"=r" (val));
> > +
> > +	if ((val & 0x2) == 0)
> > +		printk(KERN_WARNING "Warning: L2 cache not enabled. Check "
> > +		       "your bootloader. L2 off results in performance loss\n");
> > +	else
> > +		pr_info("OMAP3 L2 cache enabled\n");
> > +
> > +	return 0;
> > +}
> > +
> > +arch_initcall(omap3_check_l2cache);
> > +#endif /* CONFIG_ARCH_OMAP3 */
> 
> 
> -- 
> Best Regards,
> 
> Felipe Balbi
> me@felipebalbi.com
> http://blog.felipebalbi.com
> --
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