netdev - Re: [net-next PATCH v4 09/15] device property: Introduce fwnode_get

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAJZ5v0i9XyBKqZS9OL3riAdpmu3St_HZ3JBDcswMbX5pw03gqQ@mail.gmail.com>
Date:   Fri, 22 Jan 2021 19:13:47 +0100
From:   "Rafael J. Wysocki" <rafael@...nel.org>
To:     Calvin Johnson <calvin.johnson@....nxp.com>
Cc:     Grant Likely <grant.likely@....com>,
        "Rafael J . Wysocki" <rafael@...nel.org>,
        Jeremy Linton <jeremy.linton@....com>,
        Andrew Lunn <andrew@...n.ch>,
        Andy Shevchenko <andy.shevchenko@...il.com>,
        Florian Fainelli <f.fainelli@...il.com>,
        Russell King - ARM Linux admin <linux@...linux.org.uk>,
        Cristi Sovaiala <cristian.sovaiala@....com>,
        Florin Laurentiu Chiculita <florinlaurentiu.chiculita@....com>,
        Ioana Ciornei <ioana.ciornei@....com>,
        Madalin Bucur <madalin.bucur@....nxp.com>,
        Heikki Krogerus <heikki.krogerus@...ux.intel.com>,
        Marcin Wojtas <mw@...ihalf.com>,
        Pieter Jansen Van Vuuren <pieter.jansenvv@...boosystems.io>,
        Jon <jon@...id-run.com>, Saravana Kannan <saravanak@...gle.com>,
        Randy Dunlap <rdunlap@...radead.org>,
        "linux.cj" <linux.cj@...il.com>,
        Diana Madalina Craciun <diana.craciun@....com>,
        ACPI Devel Maling List <linux-acpi@...r.kernel.org>,
        Linux ARM <linux-arm-kernel@...ts.infradead.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        netdev <netdev@...r.kernel.org>,
        Laurentiu Tudor <laurentiu.tudor@....com>,
        Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Bartosz Golaszewski <bgolaszewski@...libre.com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Kieran Bingham <kieran.bingham+renesas@...asonboard.com>,
        Laurent Pinchart <laurent.pinchart+renesas@...asonboard.com>
Subject: Re: [net-next PATCH v4 09/15] device property: Introduce fwnode_get_id()

On Fri, Jan 22, 2021 at 4:46 PM Calvin Johnson
<calvin.johnson@....nxp.com> wrote:
>
> Using fwnode_get_id(), get the reg property value for DT node
> or get the _ADR object value for ACPI node.
>
> Signed-off-by: Calvin Johnson <calvin.johnson@....nxp.com>
> ---
>
> Changes in v4:
> - Improve code structure to handle all cases
>
> Changes in v3:
> - Modified to retrieve reg property value for ACPI as well
> - Resolved compilation issue with CONFIG_ACPI = n
> - Added more info into documentation
>
> Changes in v2: None
>
>  drivers/base/property.c  | 34 ++++++++++++++++++++++++++++++++++
>  include/linux/property.h |  1 +
>  2 files changed, 35 insertions(+)
>
> diff --git a/drivers/base/property.c b/drivers/base/property.c
> index 35b95c6ac0c6..f0581bbf7a4b 100644
> --- a/drivers/base/property.c
> +++ b/drivers/base/property.c
> @@ -580,6 +580,40 @@ const char *fwnode_get_name_prefix(const struct fwnode_handle *fwnode)
>         return fwnode_call_ptr_op(fwnode, get_name_prefix);
>  }
>
> +/**
> + * fwnode_get_id - Get the id of a fwnode.
> + * @fwnode: firmware node
> + * @id: id of the fwnode
> + *
> + * This function provides the id of a fwnode which can be either
> + * DT or ACPI node. For ACPI, "reg" property value, if present will
> + * be provided or else _ADR value will be provided.
> + * Returns 0 on success or a negative errno.
> + */
> +int fwnode_get_id(struct fwnode_handle *fwnode, u32 *id)
> +{
> +#ifdef CONFIG_ACPI
> +       unsigned long long adr;
> +       acpi_status status;
> +#endif
> +       int ret;
> +
> +       ret = fwnode_property_read_u32(fwnode, "reg", id);
> +       if (ret) {
> +#ifdef CONFIG_ACPI
> +               status = acpi_evaluate_integer(ACPI_HANDLE_FWNODE(fwnode),
> +                                              METHOD_NAME__ADR, NULL, &adr);
> +               if (ACPI_FAILURE(status))
> +                       return -EINVAL;

Please don't return -EINVAL from here, because this means "invalid
argument" to the caller, but there may be nothing wrong with the
fwnode and id pointers.

I would return -ENODATA instead.

> +               *id = (u32)adr;
> +#else
> +               return ret;
> +#endif
> +       }
> +       return 0;
> +}
> +EXPORT_SYMBOL_GPL(fwnode_get_id);
> +
>  /**
>   * fwnode_get_parent - Return parent firwmare node
>   * @fwnode: Firmware whose parent is retrieved
> diff --git a/include/linux/property.h b/include/linux/property.h
> index 0a9001fe7aea..3f41475f010b 100644
> --- a/include/linux/property.h
> +++ b/include/linux/property.h
> @@ -82,6 +82,7 @@ struct fwnode_handle *fwnode_find_reference(const struct fwnode_handle *fwnode,
>
>  const char *fwnode_get_name(const struct fwnode_handle *fwnode);
>  const char *fwnode_get_name_prefix(const struct fwnode_handle *fwnode);
> +int fwnode_get_id(struct fwnode_handle *fwnode, u32 *id);
>  struct fwnode_handle *fwnode_get_parent(const struct fwnode_handle *fwnode);
>  struct fwnode_handle *fwnode_get_next_parent(
>         struct fwnode_handle *fwnode);
> --
> 2.17.1
>