Re: [PATCH v5 4/8] char: rpmb: provide a user space interface

From: Paul Gortmaker
Date: Mon Jul 18 2016 - 18:15:59 EST


On Mon, Jul 18, 2016 at 4:27 PM, Tomas Winkler <tomas.winkler@xxxxxxxxx> wrote:
> The user space API is achieved via two synchronous IOCTL.
> Simplified one, RPMB_IOC_REQ_CMD, were read result cycles is performed
> by the framework on behalf the user and second, RPMB_IOC_SEQ_CMD where
> the whole RPMB sequence including RESULT_READ is supplied by the caller.
> The latter is intended for easier adjusting of the applications that
> use MMC_IOC_MULTI_CMD ioctl.
>
> Signed-off-by: Tomas Winkler <tomas.winkler@xxxxxxxxx>
> ---

[...]

> diff --git a/drivers/char/rpmb/Kconfig b/drivers/char/rpmb/Kconfig
> index c5e6e909efce..6794be9fcc5e 100644
> --- a/drivers/char/rpmb/Kconfig
> +++ b/drivers/char/rpmb/Kconfig
> @@ -6,3 +6,10 @@ config RPMB
> access RPMB partition.
>
> If unsure, select N.
> +
> +config RPMB_INTF_DEV
> + bool "RPMB character device interface /dev/rpmbN"

A bool Kconfig should ideally....

> + depends on RPMB
> + help
> + Say yes here if you want to access RPMB from user space
> + via character device interface /dev/rpmb%d
> diff --git a/drivers/char/rpmb/Makefile b/drivers/char/rpmb/Makefile
> index 812b3ed264c0..b5dc087b1299 100644
> --- a/drivers/char/rpmb/Makefile
> +++ b/drivers/char/rpmb/Makefile
> @@ -1,4 +1,5 @@
> obj-$(CONFIG_RPMB) += rpmb.o
> rpmb-objs += core.o
> +rpmb-$(CONFIG_RPMB_INTF_DEV) += cdev.o
>
> ccflags-y += -D__CHECK_ENDIAN__
> diff --git a/drivers/char/rpmb/cdev.c b/drivers/char/rpmb/cdev.c
> new file mode 100644
> index 000000000000..f3ad3444f76d
> --- /dev/null
> +++ b/drivers/char/rpmb/cdev.c
> @@ -0,0 +1,269 @@
> +/*
> + * Copyright (C) 2015-2016 Intel Corp. All rights reserved
> + *
> + * 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; version 2 of the License.
> + *
> + * This program is distributed in the hope that 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.
> + */
> +
> +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> +
> +#include <linux/module.h>

....not use module.h or any MODULE_ macros from within it.

Thanks,
Paul.
--

> +#include <linux/fs.h>
> +#include <linux/uaccess.h>
> +#include <linux/compat.h>
> +#include <linux/slab.h>
> +#include <linux/capability.h>
> +
> +#include <linux/rpmb.h>
> +
> +#include "rpmb-cdev.h"
> +
> +static dev_t rpmb_devt;