Re: [PATCHv4 2/5] arm: socfpga: Enable OCRAM ECC on startup.

[Dinh Nguyen <dinguyen-yzvPICuk2ABMcg4IHK0kFoH6Mc4MB0Vx@public.gmane.org>]

Hi Thor,

On 11/07/2014 10:54 AM, tthayer-yzvPICuk2ABMcg4IHK0kFoH6Mc4MB0Vx@public.gmane.org wrote:
> From: Thor Thayer <tthayer-yzvPICuk2ABMcg4IHK0kFoH6Mc4MB0Vx@public.gmane.org>
> 
> This patch enables the ECC for On-Chip RAM 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 <tthayer-yzvPICuk2ABMcg4IHK0kFoH6Mc4MB0Vx@public.gmane.org>
> ---
> v2: Split OCRAM ECC portion separately. Addition of iounmap()
> and reorganization of gen_pool_free. Remove defconfig from patch.
> 
> v3/4: No change
> ---
>  MAINTAINERS                     |    1 +
>  arch/arm/mach-socfpga/Makefile  |    1 +
>  arch/arm/mach-socfpga/ocram.c   |   90 +++++++++++++++++++++++++++++++++++++++
>  arch/arm/mach-socfpga/ocram.h   |   28 ++++++++++++
>  arch/arm/mach-socfpga/socfpga.c |    8 ++++
>  5 files changed, 128 insertions(+)
>  create mode 100644 arch/arm/mach-socfpga/ocram.c
>  create mode 100644 arch/arm/mach-socfpga/ocram.h
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index d0c7752..c6d390e 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -1408,6 +1408,7 @@ M:	Thor Thayer <tthayer-yzvPICuk2ABMcg4IHK0kFoH6Mc4MB0Vx@public.gmane.org>
>  S:	Maintained
>  F:	drivers/edac/altera_edac.
>  F:	arch/arm/mach-socfpga/l2_cache.*
> +F:	arch/arm/mach-socfpga/ocram.*

I think you can remove these entries for l2_cache.c and ocram.c since it
already falls under mach-socfpga/, which I already maintain.

>  
>  ARM/STI ARCHITECTURE
>  M:	Srinivas Kandagatla <srinivas.kandagatla-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> diff --git a/arch/arm/mach-socfpga/Makefile b/arch/arm/mach-socfpga/Makefile
> index 142609e..1552ca5 100644
> --- a/arch/arm/mach-socfpga/Makefile
> +++ b/arch/arm/mach-socfpga/Makefile
> @@ -5,3 +5,4 @@
>  obj-y					:= socfpga.o
>  obj-$(CONFIG_SMP)	+= headsmp.o platsmp.o
>  obj-$(CONFIG_EDAC_ALTERA_L2C) += l2_cache.o
> +obj-$(CONFIG_EDAC_ALTERA_OCRAM) += ocram.o
> diff --git a/arch/arm/mach-socfpga/ocram.c b/arch/arm/mach-socfpga/ocram.c
> new file mode 100644
> index 0000000..9136009
> --- /dev/null
> +++ b/arch/arm/mach-socfpga/ocram.c
> @@ -0,0 +1,90 @@
> +/*
> + * 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/genalloc.h>
> +#include <linux/of_platform.h>
> +
> +#include "ocram.h"
> +
> +void socfpga_init_ocram_ecc(void)
> +{
> +	struct device_node *np;
> +	const __be32 *prop;
> +	u32 ocr_edac_addr, iram_addr, len;
> +	void __iomem  *mapped_ocr_edac_addr;
> +	size_t size;
> +	struct gen_pool *gp;
> +
> +	np = of_find_compatible_node(NULL, NULL, "altr,ocram-edac");
> +	if (!np) {
> +		pr_err("SOCFPGA: Unable to find altr,ocram-edac in dtb\n");
> +		return;
> +	}
> +
> +	prop = of_get_property(np, "reg", &size);
> +	ocr_edac_addr = be32_to_cpup(prop++);
> +	len = be32_to_cpup(prop);

You should be checking for prop before calling be32_to_cpup.

> +	if (!prop || size < sizeof(*prop)) {

Then you don't need check for prop here.

> +		pr_err("SOCFPGA: Unable to find OCRAM ECC mapping in dtb\n");
> +		return;
> +	}
> +
> +	gp = of_get_named_gen_pool(np, "iram", 0);
> +	if (!gp) {
> +		pr_err("SOCFPGA: OCRAM cannot find gen pool\n");
> +		return;
> +	}
> +
> +	np = of_find_compatible_node(NULL, NULL, "mmio-sram");
> +	if (!np) {
> +		pr_err("SOCFPGA: Unable to find mmio-sram in dtb\n");
> +		return;
> +	}
> +	/* Determine the OCRAM address and size */
> +	prop = of_get_property(np, "reg", &size);
> +	iram_addr = be32_to_cpup(prop++);
> +	len = be32_to_cpup(prop);

Same comment here for checking prop before calling be32_to_cpu.

> +
> +	if (!prop || size < sizeof(*prop)) {
> +		pr_err("SOCFPGA: Unable to find OCRAM mapping in dtb\n");
> +		return;
> +	}
> +
> +	iram_addr = gen_pool_alloc(gp, len);
> +	if (iram_addr == 0) {
> +		pr_err("SOCFPGA: cannot alloc from gen pool\n");
> +		return;
> +	}
> +
> +	memset((void *)iram_addr, 0, len);
> +
> +	gen_pool_free(gp, iram_addr, len);
> +
> +	mapped_ocr_edac_addr = ioremap(ocr_edac_addr, 4);
> +	if (!mapped_ocr_edac_addr) {
> +		pr_err("SOCFPGA: Unable to map OCRAM ecc regs.\n");
> +		return;
> +	}
> +
> +	/* Clear any pending OCRAM ECC interrupts, then enable ECC */
> +	writel(0x18, mapped_ocr_edac_addr);
> +	writel(0x19, mapped_ocr_edac_addr);

Can you add a define for 0x18 and 0x19? What do these values mean?

> +
> +	iounmap(mapped_ocr_edac_addr);
> +
> +	pr_debug("SOCFPGA: Success Initializing OCRAM\n");
> +}
> +
> diff --git a/arch/arm/mach-socfpga/ocram.h b/arch/arm/mach-socfpga/ocram.h
> new file mode 100644
> index 0000000..f93cf84
> --- /dev/null
> +++ b/arch/arm/mach-socfpga/ocram.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_OCRAM_H
> +#define MACH_SOCFPGA_OCRAM_H
> +
> +#ifdef CONFIG_EDAC_ALTERA_OCRAM
> +void socfpga_init_ocram_ecc(void);
> +#else
> +inline void socfpga_init_ocram_ecc(void)
> +{
> +}
> +#endif
> +
> +#endif /* #ifndef MACH_SOCFPGA_OCRAM_H */
> diff --git a/arch/arm/mach-socfpga/socfpga.c b/arch/arm/mach-socfpga/socfpga.c
> index af6413a..fb41aca 100644
> --- a/arch/arm/mach-socfpga/socfpga.c
> +++ b/arch/arm/mach-socfpga/socfpga.c
> @@ -101,6 +101,13 @@ static void socfpga_cyclone5_restart(enum reboot_mode mode, const char *cmd)
>  	writel(temp, rst_manager_base_addr + SOCFPGA_RSTMGR_CTRL);
>  }
>  
> +static void __init socfpga_cyclone5_init(void)
> +{
> +	of_platform_populate(NULL, of_default_bus_match_table,
> +			     NULL, NULL);
> +	socfpga_init_ocram_ecc();

Use IS_ENABLED() here, so you can remove the need to have ocram.h. You
can put the function declaration in core.h.

Dinh


> +}
> +
>  static const char *altera_dt_match[] = {
>  	"altr,socfpga",
>  	NULL
> @@ -112,6 +119,7 @@ DT_MACHINE_START(SOCFPGA, "Altera SOCFPGA")
>  	.smp		= smp_ops(socfpga_smp_ops),
>  	.map_io		= socfpga_map_io,
>  	.init_irq	= socfpga_init_irq,
> +	.init_machine	= socfpga_cyclone5_init,
>  	.restart	= socfpga_cyclone5_restart,
>  	.dt_compat	= altera_dt_match,
>  MACHINE_END
> 

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