Re: [PATCHv6 1/5] arm: socfpga: Enable L2 Cache ECC on startup.

[Mark Rutland <mark.rutland@arm.com>]

On Fri, Jan 09, 2015 at 02:53:52AM +0000, tthayer@opensource.altera.com wrote:
> From: Thor Thayer <tthayer@opensource.altera.com>
> 
> This patch enables the ECC for L2 cache on machine
> startup.  The ECC has to be enabled before data is
> is stored in memory otherwise the ECC will fail on
> reads.

I take it you mean before the L2 cache is enabled (and its memories are
used), rather than before main memory is in use?

> 
> Signed-off-by: Thor Thayer <tthayer@opensource.altera.com>
> ---
> v2: Split OCRAM initialization into separate patch.
> 
> v3/4: No change
> 
> v5: Remove l2cache.h, use io.h instead of clk-provider.h
>     Make copyright header inclusive. Remove MAINTAINERS entry.
> 
> v6: Remove pr_debug() & update year in header.
> ---
>  arch/arm/mach-socfpga/Makefile   |    1 +
>  arch/arm/mach-socfpga/core.h     |    2 ++
>  arch/arm/mach-socfpga/l2_cache.c |   39 ++++++++++++++++++++++++++++++++++++++
>  arch/arm/mach-socfpga/socfpga.c  |    4 +++-
>  4 files changed, 45 insertions(+), 1 deletion(-)
>  create mode 100644 arch/arm/mach-socfpga/l2_cache.c
> 
> diff --git a/arch/arm/mach-socfpga/Makefile b/arch/arm/mach-socfpga/Makefile
> index 6dd7a93..142609e 100644
> --- a/arch/arm/mach-socfpga/Makefile
> +++ b/arch/arm/mach-socfpga/Makefile
> @@ -4,3 +4,4 @@
>  
>  obj-y					:= socfpga.o
>  obj-$(CONFIG_SMP)	+= headsmp.o platsmp.o
> +obj-$(CONFIG_EDAC_ALTERA_L2C) += l2_cache.o
> diff --git a/arch/arm/mach-socfpga/core.h b/arch/arm/mach-socfpga/core.h
> index 483cb46..28c8a15 100644
> --- a/arch/arm/mach-socfpga/core.h
> +++ b/arch/arm/mach-socfpga/core.h
> @@ -47,4 +47,6 @@ extern unsigned long socfpga_cpu1start_addr;
>  
>  #define SOCFPGA_SCU_VIRT_BASE   0xfffec000
>  
> +void socfpga_init_l2_ecc(void);
> +
>  #endif
> diff --git a/arch/arm/mach-socfpga/l2_cache.c b/arch/arm/mach-socfpga/l2_cache.c
> new file mode 100644
> index 0000000..047759d
> --- /dev/null
> +++ b/arch/arm/mach-socfpga/l2_cache.c
> @@ -0,0 +1,39 @@
> +/*
> + * Copyright Altera Corporation (C) 2015. All rights reserved.
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms and conditions of the GNU General Public License,
> + * version 2, as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
> + * more details.
> + *
> + * You should have received a copy of the GNU General Public License along with
> + * this program.  If not, see <http://www.gnu.org/licenses/>.
> + */
> +#include <linux/io.h>
> +#include <linux/of_platform.h>
> +#include <linux/of_address.h>
> +
> +void socfpga_init_l2_ecc(void)
> +{
> +	struct device_node *np;
> +	void __iomem  *mapped_l2_edac_addr;
> +
> +	np = of_find_compatible_node(NULL, NULL, "altr,l2-edac");
> +	if (!np) {
> +		pr_err("SOCFPGA: Unable to find altr,l2-edac in dtb\n");
> +		return;
> +	}
> +
> +	mapped_l2_edac_addr = of_iomap(np, 0);
> +	if (!mapped_l2_edac_addr) {
> +		pr_err("SOCFPGA: Unable to find L2 ECC mapping in dtb\n");
> +		return;
> +	}
> +
> +	/* Enable ECC */
> +	writel(0x01, mapped_l2_edac_addr);

Missing of_node_put(np)?

Surely you're leaking the mapping here? It's locally scoped and you
never unmap it.

Thanks,
Mark.