| 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
| ||
|
Message-ID: <CAOvb9yji5ZOQH5dxYYeFEDfX1yp+fHUgpMtaiQy72QNfyTrn+w@mail.gmail.com>
Date: Fri, 4 Mar 2022 10:11:50 -0800
From: Won Chung <wonchung@...gle.com>
To: Heikki Krogerus <heikki.krogerus@...ux.intel.com>,
Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
"Rafael J . Wysocki" <rafael@...nel.org>,
Benson Leung <bleung@...omium.org>,
Prashant Malani <pmalani@...omium.org>,
linux-kernel@...r.kernel.org
Subject: Re: [PATCH] driver core: Add sysfs support for physical location of a device
On Wed, Mar 2, 2022 at 5:37 PM Won Chung <wonchung@...gle.com> wrote:
>
> When ACPI table includes _PLD fields for a device, create a new
> directory (physical_location) in sysfs to share _PLD fields.
>
> Currently without PLD information, when there are multiple of same
> devices, it is hard to distinguish which device corresponds to which
> physical device at which location. For example, when there are two Type
> C connectors, it is hard to find out which connector corresponds to the
> Type C port on the left panel versus the Type C port on the right panel.
> With PLD information provided, we can determine which specific device at
> which location is doing what.
>
> _PLD output includes much more fields, but only generic fields are added
> and exposed to sysfs, so that non-ACPI devices can also support it in
> the future. The minimal generic fields needed for locating a device are
> the following.
> - panel
> - vertical_position
> - horizontal_position
> - dock
> - lid
>
> Signed-off-by: Won Chung <wonchung@...gle.com>
> ---
> .../ABI/testing/sysfs-devices-location | 42 ++++++
> drivers/base/core.c | 138 ++++++++++++++++++
> include/linux/device.h | 73 +++++++++
> 3 files changed, 253 insertions(+)
> create mode 100644 Documentation/ABI/testing/sysfs-devices-location
>
> diff --git a/Documentation/ABI/testing/sysfs-devices-location b/Documentation/ABI/testing/sysfs-devices-location
> new file mode 100644
> index 000000000000..bde81ce97a61
> --- /dev/null
> +++ b/Documentation/ABI/testing/sysfs-devices-location
> @@ -0,0 +1,42 @@
> +What: /sys/devices/.../location
> +Date: March 2022
> +Contact: Won Chung <wonchung@...gle.com>
> +Description:
> + This directory contains information on physical location of
> + the device connection point with respect to the system's
> + housing.
> +
> +What: /sys/devices/.../location/panel
> +Date: March 2022
> +Contact: Won Chung <wonchung@...gle.com>
> +Description:
> + Describes which panel surface of the system’s housing the
> + device connection point resides on.
> +
> +What: /sys/devices/.../location/vertical_position
> +Date: March 2022
> +Contact: Won Chung <wonchung@...gle.com>
> +Description:
> + Describes vertical position of the device connection point on
> + the panel surface.
> +
> +What: /sys/devices/.../location/horizontal_position
> +Date: March 2022
> +Contact: Won Chung <wonchung@...gle.com>
> +Description:
> + Describes horizontal position of the device connection point on
> + the panel surface.
> +
> +What: /sys/devices/.../location/dock
> +Date: March 2022
> +Contact: Won Chung <wonchung@...gle.com>
> +Description:
> + "Yes" if the device connection point resides in a docking
> + station or a port replicator. "No" otherwise.
> +
> +What: /sys/devices/.../location/lid
> +Date: March 2022
> +Contact: Won Chung <wonchung@...gle.com>
> +Description:
> + "Yes" if the device connection point resides on the lid of
> + laptop system. "No" otherwise.
> diff --git a/drivers/base/core.c b/drivers/base/core.c
> index 7bb957b11861..6b30007a319a 100644
> --- a/drivers/base/core.c
> +++ b/drivers/base/core.c
> @@ -2466,6 +2466,136 @@ static ssize_t removable_show(struct device *dev, struct device_attribute *attr,
> }
> static DEVICE_ATTR_RO(removable);
>
> +static int dev_get_and_add_location(struct device *dev)
> +{
> +#if defined(CONFIG_ACPI)
> + struct acpi_pld_info *pld;
> + acpi_status status;
> +
> + if (!has_acpi_companion(dev))
> + return 0;
> +
> + status = acpi_get_physical_device_location(ACPI_HANDLE(dev), &pld);
> + if (ACPI_FAILURE(status))
> + return 0;
> +
> + dev->location = (struct device_location) {
> + .panel = pld->panel,
> + .vertical_position = pld->vertical_position,
> + .horizontal_position = pld->horizontal_position,
> + .dock = pld->dock,
> + .lid = pld->lid,
> + };
> +
> + return 1;
> +#else
> + return 0;
> +#endif
> +}
> +
> +static ssize_t panel_show(struct device *dev, struct device_attribute *attr,
> + char *buf)
> +{
> + const char *panel;
> +
> + switch (dev->location.panel) {
> + case DEVICE_PANEL_TOP:
> + panel = "top";
> + break;
> + case DEVICE_PANEL_BOTTOM:
> + panel = "bottom";
> + break;
> + case DEVICE_PANEL_LEFT:
> + panel = "left";
> + break;
> + case DEVICE_PANEL_RIGHT:
> + panel = "right";
> + break;
> + case DEVICE_PANEL_FRONT:
> + panel = "front";
> + break;
> + case DEVICE_PANEL_BACK:
> + panel = "back";
> + break;
> + default:
> + panel = "unknown";
> + }
> + return sprintf(buf, "%s\n", panel);
> +}
> +static DEVICE_ATTR_RO(panel);
> +
> +static ssize_t vertical_position_show(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + const char *vertical_position;
> +
> + switch (dev->location.vertical_position) {
> + case DEVICE_VERT_POS_UPPER:
> + vertical_position = "upper";
> + break;
> + case DEVICE_VERT_POS_CENTER:
> + vertical_position = "center";
> + break;
> + case DEVICE_VERT_POS_LOWER:
> + vertical_position = "lower";
> + break;
> + default:
> + vertical_position = "unknown";
> + }
> + return sprintf(buf, "%s\n", vertical_position);
> +}
> +static DEVICE_ATTR_RO(vertical_position);
> +
> +static ssize_t horizontal_position_show(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + const char *horizontal_position;
> +
> + switch (dev->location.horizontal_position) {
> + case DEVICE_HORI_POS_LEFT:
> + horizontal_position = "left";
> + break;
> + case DEVICE_HORI_POS_CENTER:
> + horizontal_position = "center";
> + break;
> + case DEVICE_HORI_POS_RIGHT:
> + horizontal_position = "right";
> + break;
> + default:
> + horizontal_position = "unknown";
> + }
> + return sprintf(buf, "%s\n", horizontal_position);
> +}
> +static DEVICE_ATTR_RO(horizontal_position);
> +
> +static ssize_t dock_show(struct device *dev, struct device_attribute *attr,
> + char *buf)
> +{
> + return sprintf(buf, "%s\n", dev->location.dock ? "yes" : "no");
> +}
> +static DEVICE_ATTR_RO(dock);
> +
> +static ssize_t lid_show(struct device *dev, struct device_attribute *attr,
> + char *buf)
> +{
> + return sprintf(buf, "%s\n", dev->location.lid ? "yes" : "no");
> +}
> +static DEVICE_ATTR_RO(lid);
> +
> +static struct attribute *dev_attr_location[] = {
> + &dev_attr_panel.attr,
> + &dev_attr_vertical_position.attr,
> + &dev_attr_horizontal_position.attr,
> + &dev_attr_dock.attr,
> + &dev_attr_lid.attr,
> + NULL,
> +};
> +
> +static const struct attribute_group dev_attr_location_group = {
> + .name = "physical_location",
> + .attrs = dev_attr_location,
> +};
> +
> int device_add_groups(struct device *dev, const struct attribute_group **groups)
> {
> return sysfs_create_groups(&dev->kobj, groups);
> @@ -2649,8 +2779,16 @@ static int device_add_attrs(struct device *dev)
> goto err_remove_dev_waiting_for_supplier;
> }
>
> + if (dev_get_and_add_location(dev)) {
> + error = device_add_group(dev, &dev_attr_location_group);
> + if (error)
> + goto err_remove_dev_location;
> + }
> +
> return 0;
>
> + err_remove_dev_location:
> + device_remove_group(dev, &dev_attr_location_group);
> err_remove_dev_waiting_for_supplier:
> device_remove_file(dev, &dev_attr_waiting_for_supplier);
> err_remove_dev_online:
> diff --git a/include/linux/device.h b/include/linux/device.h
> index 93459724dcde..424be9cb735e 100644
> --- a/include/linux/device.h
> +++ b/include/linux/device.h
> @@ -386,6 +386,75 @@ struct dev_msi_info {
> #endif
> };
>
> +/**
> + * enum device_location_panel - Describes which panel surface of the system's
> + * housing the device connection point resides on.
> + * @DEVICE_PANEL_TOP: Device connection point is on the top panel.
> + * @DEVICE_PANEL_BOTTOM: Device connection point is on the bottom panel.
> + * @DEVICE_PANEL_LEFT: Device connection point is on the left panel.
> + * @DEVICE_PANEL_RIGHT: Device connection point is on the right panel.
> + * @DEVICE_PANEL_FRONT: Device connection point is on the front panel.
> + * @DEVICE_PANEL_BACK: Device connection point is on the back panel.
> + * @DEVICE_PANEL_UNKNOWN: The panel with device connection point is unknown.
> + */
> +enum device_location_panel {
> + DEVICE_PANEL_TOP,
> + DEVICE_PANEL_BOTTOM,
> + DEVICE_PANEL_LEFT,
> + DEVICE_PANEL_RIGHT,
> + DEVICE_PANEL_FRONT,
> + DEVICE_PANEL_BACK,
> + DEVICE_PANEL_UNKNOWN,
> +};
> +
> +/**
> + * enum device_location_vertical_position - Describes vertical position of the
> + * device connection point on the panel surface.
> + * @DEVICE_VERT_POS_UPPER: Device connection point is at upper part of panel.
> + * @DEVICE_VERT_POS_CENTER: Device connection point is at center part of panel.
> + * @DEVICE_VERT_POS_LOWER: Device connection point is at lower part of panel.
> + */
> +enum device_location_vertical_position {
> + DEVICE_VERT_POS_UPPER,
> + DEVICE_VERT_POS_CENTER,
> + DEVICE_VERT_POS_LOWER,
> +};
> +
> +/**
> + * enum device_location_horizontal_position - Describes horizontal position of
> + * the device connection point on the panel surface.
> + * @DEVICE_HORI_POS_LEFT: Device connection point is at left part of panel.
> + * @DEVICE_HORI_POS_CENTER: Device connection point is at center part of panel.
> + * @DEVICE_HORI_POS_RIGHT: Device connection point is at right part of panel.
> + */
> +enum device_location_horizontal_position {
> + DEVICE_HORI_POS_LEFT,
> + DEVICE_HORI_POS_CENTER,
> + DEVICE_HORI_POS_RIGHT,
> +};
> +
> +/**
> + * struct device_location - Device data related to physical location of the
> + * device connection point.
> + * @panel: Panel surface of the system's housing that the device connection
> + * point resides on.
> + * @vertical_position: Vertical position of the device connection point within
> + * the panel.
> + * @horizontal_position: Horizontal position of the device connection point
> + * within the panel.
> + * @dock: Set if the device connection point resides in a docking station or
> + * port replicator.
> + * @lid: Set if this device connection point resides on the lid of laptop
> + * system.
> + */
> +struct device_location {
> + enum device_location_panel panel;
> + enum device_location_vertical_position vertical_position;
> + enum device_location_horizontal_position horizontal_position;
> + bool dock;
> + bool lid;
> +};
> +
> /**
> * struct device - The basic device structure
> * @parent: The device's "parent" device, the device to which it is attached.
> @@ -456,6 +525,8 @@ struct dev_msi_info {
> * @removable: Whether the device can be removed from the system. This
> * should be set by the subsystem / bus driver that discovered
> * the device.
> + * @location: Describes physical location of the device connection point in
> + * the system housing.
> *
> * @offline_disabled: If set, the device is permanently online.
> * @offline: Set after successful invocation of bus type's .offline().
> @@ -569,6 +640,8 @@ struct device {
>
> enum device_removable removable;
>
> + struct device_location location;
> +
> bool offline_disabled:1;
> bool offline:1;
> bool of_node_reused:1;
> --
> 2.35.1.574.g5d30c73bfb-goog
>
Hi,
I will send a new patch v2 to correct directory names in Documentation
and also clarify some naming in core.c.
Won
Powered by blists - more mailing lists