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From: Dan Williams <dan.j.williams@intel.com>
To: Iwona Winiarska <iwona.winiarska@intel.com>
Cc: linux-aspeed@lists.ozlabs.org,
	Linux Doc Mailing List <linux-doc@vger.kernel.org>,
	Jason M Bills <jason.m.bills@linux.intel.com>,
	Zev Weiss <zweiss@equinix.com>,
	Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	Jonathan Corbet <corbet@lwn.net>,
	openbmc@lists.ozlabs.org, X86 ML <x86@kernel.org>,
	Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>,
	Ingo Molnar <mingo@redhat.com>,
	Guenter Roeck <linux@roeck-us.net>,
	Device Tree <devicetree@vger.kernel.org>,
	Jean Delvare <jdelvare@suse.com>, Arnd Bergmann <arnd@arndb.de>,
	Rob Herring <robh+dt@kernel.org>, Borislav Petkov <bp@alien8.de>,
	Andy Lutomirski <luto@kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Mauro Carvalho Chehab <mchehab@kernel.org>,
	Linux ARM <linux-arm-kernel@lists.infradead.org>,
	linux-hwmon@vger.kernel.org, Tony Luck <tony.luck@intel.com>,
	Andrew Jeffery <andrew@aj.id.au>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Randy Dunlap <rdunlap@infradead.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Yazen Ghannam <yazen.ghannam@amd.com>,
	Olof Johansson <olof@lixom.net>
Subject: Re: [PATCH v2 06/15] peci: Add core infrastructure
Date: Wed, 25 Aug 2021 15:58:53 -0700	[thread overview]
Message-ID: <CAPcyv4giVBjZWjXO2H+vYSR29Vapi6_FvMwO7nvts-JXmCHcOA@mail.gmail.com> (raw)
In-Reply-To: <20210803113134.2262882-7-iwona.winiarska@intel.com>

On Tue, Aug 3, 2021 at 4:35 AM Iwona Winiarska
<iwona.winiarska@intel.com> wrote:
>
> Intel processors provide access for various services designed to support
> processor and DRAM thermal management, platform manageability and
> processor interface tuning and diagnostics.
> Those services are available via the Platform Environment Control
> Interface (PECI) that provides a communication channel between the
> processor and the Baseboard Management Controller (BMC) or other
> platform management device.
>
> This change introduces PECI subsystem by adding the initial core module
> and API for controller drivers.
>
> Co-developed-by: Jason M Bills <jason.m.bills@linux.intel.com>
> Signed-off-by: Jason M Bills <jason.m.bills@linux.intel.com>
> Co-developed-by: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>
> Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>
> Signed-off-by: Iwona Winiarska <iwona.winiarska@intel.com>
> Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
> ---
>  MAINTAINERS             |   9 +++
>  drivers/Kconfig         |   3 +
>  drivers/Makefile        |   1 +
>  drivers/peci/Kconfig    |  15 ++++
>  drivers/peci/Makefile   |   5 ++
>  drivers/peci/core.c     | 155 ++++++++++++++++++++++++++++++++++++++++
>  drivers/peci/internal.h |  16 +++++
>  include/linux/peci.h    |  99 +++++++++++++++++++++++++
>  8 files changed, 303 insertions(+)
>  create mode 100644 drivers/peci/Kconfig
>  create mode 100644 drivers/peci/Makefile
>  create mode 100644 drivers/peci/core.c
>  create mode 100644 drivers/peci/internal.h
>  create mode 100644 include/linux/peci.h
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 7cdab7229651..d411974aaa5e 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -14503,6 +14503,15 @@ L:     platform-driver-x86@vger.kernel.org
>  S:     Maintained
>  F:     drivers/platform/x86/peaq-wmi.c
>
> +PECI SUBSYSTEM
> +M:     Iwona Winiarska <iwona.winiarska@intel.com>
> +R:     Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>
> +L:     openbmc@lists.ozlabs.org (moderated for non-subscribers)
> +S:     Supported
> +F:     Documentation/devicetree/bindings/peci/
> +F:     drivers/peci/
> +F:     include/linux/peci.h
> +
>  PENSANDO ETHERNET DRIVERS
>  M:     Shannon Nelson <snelson@pensando.io>
>  M:     drivers@pensando.io
> diff --git a/drivers/Kconfig b/drivers/Kconfig
> index 8bad63417a50..f472b3d972b3 100644
> --- a/drivers/Kconfig
> +++ b/drivers/Kconfig
> @@ -236,4 +236,7 @@ source "drivers/interconnect/Kconfig"
>  source "drivers/counter/Kconfig"
>
>  source "drivers/most/Kconfig"
> +
> +source "drivers/peci/Kconfig"
> +
>  endmenu
> diff --git a/drivers/Makefile b/drivers/Makefile
> index 27c018bdf4de..8d96f0c3dde5 100644
> --- a/drivers/Makefile
> +++ b/drivers/Makefile
> @@ -189,3 +189,4 @@ obj-$(CONFIG_GNSS)          += gnss/
>  obj-$(CONFIG_INTERCONNECT)     += interconnect/
>  obj-$(CONFIG_COUNTER)          += counter/
>  obj-$(CONFIG_MOST)             += most/
> +obj-$(CONFIG_PECI)             += peci/
> diff --git a/drivers/peci/Kconfig b/drivers/peci/Kconfig
> new file mode 100644
> index 000000000000..71a4ad81225a
> --- /dev/null
> +++ b/drivers/peci/Kconfig
> @@ -0,0 +1,15 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +
> +menuconfig PECI
> +       tristate "PECI support"
> +       help
> +         The Platform Environment Control Interface (PECI) is an interface
> +         that provides a communication channel to Intel processors and
> +         chipset components from external monitoring or control devices.
> +
> +         If you are building a Baseboard Management Controller (BMC) kernel
> +         for Intel platform say Y here and also to the specific driver for
> +         your adapter(s) below. If unsure say N.
> +
> +         This support is also available as a module. If so, the module
> +         will be called peci.
> diff --git a/drivers/peci/Makefile b/drivers/peci/Makefile
> new file mode 100644
> index 000000000000..e789a354e842
> --- /dev/null
> +++ b/drivers/peci/Makefile
> @@ -0,0 +1,5 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +
> +# Core functionality
> +peci-y := core.o
> +obj-$(CONFIG_PECI) += peci.o
> diff --git a/drivers/peci/core.c b/drivers/peci/core.c
> new file mode 100644
> index 000000000000..7b3938af0396
> --- /dev/null
> +++ b/drivers/peci/core.c
> @@ -0,0 +1,155 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +// Copyright (c) 2018-2021 Intel Corporation
> +
> +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

This looks like overkill for only one print statement in this module,
especially when the dev_ print helpers offer more detail.

> +
> +#include <linux/bug.h>
> +#include <linux/device.h>
> +#include <linux/export.h>
> +#include <linux/idr.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/peci.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/property.h>
> +#include <linux/slab.h>
> +
> +#include "internal.h"
> +
> +static DEFINE_IDA(peci_controller_ida);
> +
> +static void peci_controller_dev_release(struct device *dev)
> +{
> +       struct peci_controller *controller = to_peci_controller(dev);
> +
> +       pm_runtime_disable(&controller->dev);

This seems late to be disabling power management, the device is about
to be freed. Keep in mind the lifetime of the this object can be
artificially prolonged. I expect this to be done when the device is
unregistered from the bus.

> +
> +       mutex_destroy(&controller->bus_lock);
> +       ida_free(&peci_controller_ida, controller->id);
> +       fwnode_handle_put(controller->dev.fwnode);

Shouldn't the get / put of this handle reference be bound to specific
accesses not held for the entire lifetime of the object? At a minimum
it seems to be a reference that can taken at registration and dropped
at unregistration.

> +       kfree(controller);
> +}
> +
> +struct device_type peci_controller_type = {
> +       .release        = peci_controller_dev_release,
> +};
> +
> +static struct peci_controller *peci_controller_alloc(struct device *dev,
> +                                                    struct peci_controller_ops *ops)
> +{
> +       struct fwnode_handle *node = fwnode_handle_get(dev_fwnode(dev));
> +       struct peci_controller *controller;
> +       int ret;
> +
> +       if (!ops->xfer)
> +               return ERR_PTR(-EINVAL);
> +
> +       controller = kzalloc(sizeof(*controller), GFP_KERNEL);
> +       if (!controller)
> +               return ERR_PTR(-ENOMEM);
> +
> +       ret = ida_alloc_max(&peci_controller_ida, U8_MAX, GFP_KERNEL);
> +       if (ret < 0)
> +               goto err;
> +       controller->id = ret;
> +
> +       controller->ops = ops;
> +
> +       controller->dev.parent = dev;
> +       controller->dev.bus = &peci_bus_type;
> +       controller->dev.type = &peci_controller_type;
> +       controller->dev.fwnode = node;
> +       controller->dev.of_node = to_of_node(node);
> +
> +       device_initialize(&controller->dev);
> +
> +       mutex_init(&controller->bus_lock);
> +
> +       pm_runtime_no_callbacks(&controller->dev);
> +       pm_suspend_ignore_children(&controller->dev, true);
> +       pm_runtime_enable(&controller->dev);

Per above, are you sure unregistered devices need pm_runtime enabled?

Rest looks ok to me.

  reply	other threads:[~2021-08-26  3:53 UTC|newest]

Thread overview: 49+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-03 11:31 [PATCH v2 00/15] Introduce PECI subsystem Iwona Winiarska
2021-08-03 11:31 ` [PATCH v2 01/15] x86/cpu: Move intel-family to arch-independent headers Iwona Winiarska
2021-10-04 19:03   ` Borislav Petkov
2021-10-11 19:21     ` Winiarska, Iwona
2021-10-11 19:40       ` Dave Hansen
2021-10-11 20:53         ` Winiarska, Iwona
2021-10-11 23:12           ` Dave Hansen
2021-10-11 20:06       ` Borislav Petkov
2021-10-11 20:38         ` Winiarska, Iwona
2021-10-11 21:31           ` Borislav Petkov
2021-10-12 23:15             ` Winiarska, Iwona
2021-10-13  6:42               ` Borislav Petkov
2021-08-03 11:31 ` [PATCH v2 02/15] x86/cpu: Extract cpuid helpers to arch-independent Iwona Winiarska
2021-10-04 19:08   ` Borislav Petkov
2021-10-11 19:32     ` Winiarska, Iwona
2021-08-03 11:31 ` [PATCH v2 03/15] dt-bindings: Add generic bindings for PECI Iwona Winiarska
2021-08-11 18:11   ` Rob Herring
2021-08-03 11:31 ` [PATCH v2 04/15] dt-bindings: Add bindings for peci-aspeed Iwona Winiarska
2021-08-11 18:11   ` Rob Herring
2021-08-03 11:31 ` [PATCH v2 05/15] ARM: dts: aspeed: Add PECI controller nodes Iwona Winiarska
2021-08-03 11:31 ` [PATCH v2 06/15] peci: Add core infrastructure Iwona Winiarska
2021-08-25 22:58   ` Dan Williams [this message]
2021-08-26 22:40     ` Winiarska, Iwona
2021-08-03 11:31 ` [PATCH v2 07/15] peci: Add peci-aspeed controller driver Iwona Winiarska
2021-08-26  1:35   ` Dan Williams
2021-08-26 23:54     ` Winiarska, Iwona
2021-08-27 16:24       ` Dan Williams
2021-08-29 19:42         ` Winiarska, Iwona
2021-08-03 11:31 ` [PATCH v2 08/15] peci: Add device detection Iwona Winiarska
2021-08-27 19:01   ` Dan Williams
2021-11-15 22:18     ` Winiarska, Iwona
2021-08-03 11:31 ` [PATCH v2 09/15] peci: Add sysfs interface for PECI bus Iwona Winiarska
2021-08-27 19:11   ` Dan Williams
2021-11-15 22:19     ` Winiarska, Iwona
2021-08-03 11:31 ` [PATCH v2 10/15] peci: Add support for PECI device drivers Iwona Winiarska
2021-08-27 21:19   ` Dan Williams
2021-11-15 22:20     ` Winiarska, Iwona
2021-08-03 11:31 ` [PATCH v2 11/15] peci: Add peci-cpu driver Iwona Winiarska
2021-08-03 11:31 ` [PATCH v2 12/15] hwmon: peci: Add cputemp driver Iwona Winiarska
2021-08-03 15:24   ` Guenter Roeck
2021-08-04 10:43     ` Winiarska, Iwona
2021-08-03 11:31 ` [PATCH v2 13/15] hwmon: peci: Add dimmtemp driver Iwona Winiarska
2021-08-03 15:39   ` Guenter Roeck
2021-08-04 10:46     ` Winiarska, Iwona
2021-08-04 17:33       ` Guenter Roeck
2021-08-05 21:48         ` Winiarska, Iwona
2021-08-03 11:31 ` [PATCH v2 14/15] docs: hwmon: Document PECI drivers Iwona Winiarska
2021-08-03 11:31 ` [PATCH v2 15/15] docs: Add PECI documentation Iwona Winiarska
2021-08-05 12:17 ` [PATCH v2 00/15] Introduce PECI subsystem Greg Kroah-Hartman

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