[PATCH v3] powerpc/powernv: add hdat attribute to sysfs

[Andrew Donnellan]

On 24/02/17 17:20, Matt Brown wrote:
> The HDAT data area is consumed by skiboot and turned into a device-tree.
> In some cases we would like to look directly at the HDAT, so this patch
> adds a sysfs node to allow it to be viewed.  This is not possible through
> /dev/mem as it is reserved memory which is stopped by the /dev/mem filter.
>
> Signed-off-by: Matt Brown <matthew.brown.dev at gmail.com>

Changes look good, thanks for addressing the comments! Still a couple of 
minor points below, otherwise:

Reviewed-by: Andrew Donnellan <andrew.donnellan at au1.ibm.com>

Stewart: this might need your ACK?

> ---
>
> Changes between v2 to v3:
> 	- fixed header comments
> 	- simplified if statement
>
> ---
>  arch/powerpc/include/asm/opal.h            |  1 +
>  arch/powerpc/platforms/powernv/Makefile    |  1 +
>  arch/powerpc/platforms/powernv/opal-hdat.c | 65 ++++++++++++++++++++++++++++++
>  arch/powerpc/platforms/powernv/opal.c      |  2 +
>  4 files changed, 69 insertions(+)
>  create mode 100644 arch/powerpc/platforms/powernv/opal-hdat.c
>
> diff --git a/arch/powerpc/include/asm/opal.h b/arch/powerpc/include/asm/opal.h
> index 5c7db0f..b26944e 100644
> --- a/arch/powerpc/include/asm/opal.h
> +++ b/arch/powerpc/include/asm/opal.h
> @@ -277,6 +277,7 @@ extern int opal_async_comp_init(void);
>  extern int opal_sensor_init(void);
>  extern int opal_hmi_handler_init(void);
>  extern int opal_event_init(void);
> +extern void opal_hdat_sysfs_init(void);
>
>  extern int opal_machine_check(struct pt_regs *regs);
>  extern bool opal_mce_check_early_recovery(struct pt_regs *regs);
> diff --git a/arch/powerpc/platforms/powernv/Makefile b/arch/powerpc/platforms/powernv/Makefile
> index b5d98cb..9a0c9d6 100644
> --- a/arch/powerpc/platforms/powernv/Makefile
> +++ b/arch/powerpc/platforms/powernv/Makefile
> @@ -3,6 +3,7 @@ obj-y			+= opal-rtc.o opal-nvram.o opal-lpc.o opal-flash.o
>  obj-y			+= rng.o opal-elog.o opal-dump.o opal-sysparam.o opal-sensor.o
>  obj-y			+= opal-msglog.o opal-hmi.o opal-power.o opal-irqchip.o
>  obj-y			+= opal-kmsg.o
> +obj-y			+= opal-hdat.o

Normally we keep putting new object files on the same line until it gets 
long enough that we have to break it. This is very minor though :)

>
>  obj-$(CONFIG_SMP)	+= smp.o subcore.o subcore-asm.o
>  obj-$(CONFIG_PCI)	+= pci.o pci-ioda.o npu-dma.o
> diff --git a/arch/powerpc/platforms/powernv/opal-hdat.c b/arch/powerpc/platforms/powernv/opal-hdat.c
> new file mode 100644
> index 0000000..3315dd3
> --- /dev/null
> +++ b/arch/powerpc/platforms/powernv/opal-hdat.c
> @@ -0,0 +1,65 @@
> +/*
> + * PowerNV OPAL HDAT interface
> + *
> + * Author: Matt Brown <matthew.brown.dev at gmail.com>
> + *
> + * Copyright 2017 IBM Corp.
> + *
> + * 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 the Free Software Foundation; either version
> + * 2 of the License, or (at your option) any later version.
> + */
> +
> +#include <asm/io.h>
> +#include <asm/opal.h>
> +#include <linux/of.h>
> +#include <linux/types.h>
> +
> +struct hdat_info {
> +	char *base;
> +	u64 size;
> +};
> +
> +static struct hdat_info hdat_inf;

As Oliver pointed out, we could do with a better name than hdat_inf - 
it's only one character away from the name of the struct type. Hmm, 
perhaps "hdat_location", or maybe Oliver has a better suggestion.


-- 
Andrew Donnellan              OzLabs, ADL Canberra
andrew.donnellan at au1.ibm.com  IBM Australia Limited