Subject: [PATCHv4 1/5] arm: socfpga: Enable L2 Cache ECC on startup.

From: [email-masked] (Dinh Nguyen)
Date: Fri, 7 Nov 2014 14:13:06 -0600

Hi Thor,

On 11/07/2014 10:54 AM, tthayer at opensource.altera.com wrote:
> From: Thor Thayer <[email-masked]>
> 
> 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.
> 
> Signed-off-by: Thor Thayer <[email-masked]>
> ---
> v2: Split OCRAM initialization into separate patch.
> 
> v3/4: No change
> ---
>  MAINTAINERS                      |    1 +
>  arch/arm/mach-socfpga/Makefile   |    1 +
>  arch/arm/mach-socfpga/l2_cache.c |   44 ++++++++++++++++++++++++++++++++++++++
>  arch/arm/mach-socfpga/l2_cache.h |   28 ++++++++++++++++++++++++
>  arch/arm/mach-socfpga/socfpga.c  |    5 ++++-
>  5 files changed, 78 insertions(+), 1 deletion(-)
>  create mode 100644 arch/arm/mach-socfpga/l2_cache.c
>  create mode 100644 arch/arm/mach-socfpga/l2_cache.h
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index ee1bc5b..d0c7752 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -1407,6 +1407,7 @@ ARM/SOCFPGA EDAC SUPPORT
>  M:	Thor Thayer <[email-masked]>
>  S:	Maintained
>  F:	drivers/edac/altera_edac.
> +F:	arch/arm/mach-socfpga/l2_cache.*
>  
>  ARM/STI ARCHITECTURE
>  M:	Srinivas Kandagatla <[email-masked]>
> 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/l2_cache.c b/arch/arm/mach-socfpga/l2_cache.c
> new file mode 100644
> index 0000000..8e109f3
> --- /dev/null
> +++ b/arch/arm/mach-socfpga/l2_cache.c
> @@ -0,0 +1,44 @@
> +/*
> + * Copyright Altera Corporation (C) 2014. 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/clk-provider.h>

Why clk-provider.h and not io.h?

> +#include <linux/of_platform.h>
> +#include <linux/of_address.h>
> +
> +#include "l2_cache.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);
> +
> +	pr_debug("SOCFPGA: Success Initializing L2 cache ECC\n");
> +}
> +

Extra line here...

> diff --git a/arch/arm/mach-socfpga/l2_cache.h b/arch/arm/mach-socfpga/l2_cache.h
> new file mode 100644
> index 0000000..58e140d
> --- /dev/null
> +++ b/arch/arm/mach-socfpga/l2_cache.h
> @@ -0,0 +1,28 @@
> +/*
> + * Copyright Altera Corporation (C) 2014. 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/>.
> + */
> +
> +#ifndef MACH_SOCFPGA_L2_CACHE_H
> +#define MACH_SOCFPGA_L2_CACHE_H
> +
> +#ifdef CONFIG_EDAC_ALTERA_L2C
> +void socfpga_init_l2_ecc(void);
> +#else
> +inline void socfpga_init_l2_ecc(void)
> +{
> +}
> +#endif
> +
> +#endif /* #ifndef MACH_SOCFPGA_L2_CACHE_H */
> diff --git a/arch/arm/mach-socfpga/socfpga.c b/arch/arm/mach-socfpga/socfpga.c
> index adbf383..af6413a 100644
> --- a/arch/arm/mach-socfpga/socfpga.c
> +++ b/arch/arm/mach-socfpga/socfpga.c
> @@ -1,5 +1,5 @@
>  /*
> - *  Copyright (C) 2012 Altera Corporation
> + *  Copyright (C) 2012;2014 Altera Corporation

Should be "2012-2014".

>   *
>   * This program is free software; you can redistribute it and/or modify
>   * it under the terms of the GNU General Public License as published by
> @@ -25,6 +25,8 @@
>  #include <asm/mach/map.h>
>  
>  #include "core.h"
> +#include "l2_cache.h"
> +#include "ocram.h"

Including ocram.h should go into patch 2/5. But I think ocram.h can be
removed as well if you just use IS_ENABLED().

>  
>  void __iomem *socfpga_scu_base_addr = ((void __iomem *)(SOCFPGA_SCU_VIRT_BASE));
>  void __iomem *sys_manager_base_addr;
> @@ -83,6 +85,7 @@ static void __init socfpga_init_irq(void)
>  {
>  	irqchip_init();
>  	socfpga_sysmgr_init();
> +	socfpga_init_l2_ecc();

If you use "if (IS_ENABLED(CONFIG_EDAC_ALTERA_L2C))", then you can
remove l2_cache.h.

Dinh