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| author | Barry Song <song.bao.hua@hisilicon.com> | 2020-06-19 15:00:45 +1200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-07-10 14:14:37 +0200 |
| commit | 4a60406d3592373b8fd27ddfd010c5e62ad6c674 (patch) | |
| tree | c222443b64feee47c2db0bb8cedc8b96d3fa1c77 | |
| parent | 079ad2fb4bf9eba8a0aaab014b49705cd7f07c66 (diff) | |
| download | lwn-4a60406d3592373b8fd27ddfd010c5e62ad6c674.tar.gz lwn-4a60406d3592373b8fd27ddfd010c5e62ad6c674.zip | |
driver core: platform: expose numa_node to users in sysfs
Some platform devices like ARM SMMU are memory-mapped and populated by ACPI/IORT.
In this case, NUMA topology of those platform devices are exported by firmware as
well. Software might care about the numa_node of those devices in order to achieve
NUMA locality.
This patch will show the numa_node for this kind of devices in sysfs. For those
platform devices without numa, numa_node won't be visible.
Cc: Prime Zeng <prime.zeng@hisilicon.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Barry Song <song.bao.hua@hisilicon.com>
Link: https://lore.kernel.org/r/20200619030045.81956-1-song.bao.hua@hisilicon.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | Documentation/ABI/testing/sysfs-bus-platform | 10 | ||||
| -rw-r--r-- | drivers/base/platform.c | 26 |
2 files changed, 35 insertions, 1 deletions
diff --git a/Documentation/ABI/testing/sysfs-bus-platform b/Documentation/ABI/testing/sysfs-bus-platform index 5172a6124b27..194ca700e962 100644 --- a/Documentation/ABI/testing/sysfs-bus-platform +++ b/Documentation/ABI/testing/sysfs-bus-platform @@ -18,3 +18,13 @@ Description: devices to opt-out of driver binding using a driver_override name such as "none". Only a single driver may be specified in the override, there is no support for parsing delimiters. + +What: /sys/bus/platform/devices/.../numa_node +Date: June 2020 +Contact: Barry Song <song.bao.hua@hisilicon.com> +Description: + This file contains the NUMA node to which the platform device + is attached. It won't be visible if the node is unknown. The + value comes from an ACPI _PXM method or a similar firmware + source. Initial users for this file would be devices like + arm smmu which are populated by arm64 acpi_iort. diff --git a/drivers/base/platform.c b/drivers/base/platform.c index 3273a2fad4ad..e5d8a0503b4f 100644 --- a/drivers/base/platform.c +++ b/drivers/base/platform.c @@ -1076,13 +1076,37 @@ static ssize_t driver_override_show(struct device *dev, } static DEVICE_ATTR_RW(driver_override); +static ssize_t numa_node_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + return sprintf(buf, "%d\n", dev_to_node(dev)); +} +static DEVICE_ATTR_RO(numa_node); + +static umode_t platform_dev_attrs_visible(struct kobject *kobj, struct attribute *a, + int n) +{ + struct device *dev = container_of(kobj, typeof(*dev), kobj); + + if (a == &dev_attr_numa_node.attr && + dev_to_node(dev) == NUMA_NO_NODE) + return 0; + + return a->mode; +} static struct attribute *platform_dev_attrs[] = { &dev_attr_modalias.attr, + &dev_attr_numa_node.attr, &dev_attr_driver_override.attr, NULL, }; -ATTRIBUTE_GROUPS(platform_dev); + +static struct attribute_group platform_dev_group = { + .attrs = platform_dev_attrs, + .is_visible = platform_dev_attrs_visible, +}; +__ATTRIBUTE_GROUPS(platform_dev); static int platform_uevent(struct device *dev, struct kobj_uevent_env *env) { |