On 22-01-23 16:31:24, Dan Williams wrote:
> While CXL memory targets will have their own memory target node,
> individual memory devices may be affinitized like other PCI devices.
> Emit that attribute for memdevs.
>
> Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
This brings up an interesting question. Are all devices in a region affinitized
to the same NUMA node? I think they must be - at which point, should this
attribute be a part of a region, rather than a device?
> ---
> Documentation/ABI/testing/sysfs-bus-cxl | 9 +++++++++
> drivers/cxl/core/memdev.c | 17 +++++++++++++++++
> tools/testing/cxl/test/cxl.c | 1 +
> 3 files changed, 27 insertions(+)
>
> diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl
> index 87c0e5e65322..0b51cfec0c66 100644
> --- a/Documentation/ABI/testing/sysfs-bus-cxl
> +++ b/Documentation/ABI/testing/sysfs-bus-cxl
> @@ -34,6 +34,15 @@ Description:
> capability. Mandatory for CXL devices, see CXL 2.0 8.1.12.2
> Memory Device PCIe Capabilities and Extended Capabilities.
>
> +What: /sys/bus/cxl/devices/memX/numa_node
> +Date: January, 2022
> +KernelVersion: v5.18
> +Contact: linux-cxl@xxxxxxxxxxxxxxx
> +Description:
> + (RO) If NUMA is enabled and the platform has affinitized the
> + host PCI device for this memory device, emit the CPU node
> + affinity for this device.
> +
I think you'd want to say something about the device actively decoding. Perhaps
I'm mistaken though, can you affinitize without setting up HDM decoders for the
device?
> What: /sys/bus/cxl/devices/*/devtype
> Date: June, 2021
> KernelVersion: v5.14
> diff --git a/drivers/cxl/core/memdev.c b/drivers/cxl/core/memdev.c
> index 1e574b052583..b2773664e407 100644
> --- a/drivers/cxl/core/memdev.c
> +++ b/drivers/cxl/core/memdev.c
> @@ -99,11 +99,19 @@ static ssize_t serial_show(struct device *dev, struct device_attribute *attr,
> }
> static DEVICE_ATTR_RO(serial);
>
> +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 struct attribute *cxl_memdev_attributes[] = {
> &dev_attr_serial.attr,
> &dev_attr_firmware_version.attr,
> &dev_attr_payload_max.attr,
> &dev_attr_label_storage_size.attr,
> + &dev_attr_numa_node.attr,
> NULL,
> };
>
> @@ -117,8 +125,17 @@ static struct attribute *cxl_memdev_ram_attributes[] = {
> NULL,
> };
>
> +static umode_t cxl_memdev_visible(struct kobject *kobj, struct attribute *a,
> + int n)
> +{
> + if (!IS_ENABLED(CONFIG_NUMA) && a == &dev_attr_numa_node.attr)
> + return 0;
> + return a->mode;
> +}
> +
> static struct attribute_group cxl_memdev_attribute_group = {
> .attrs = cxl_memdev_attributes,
> + .is_visible = cxl_memdev_visible,
> };
>
> static struct attribute_group cxl_memdev_ram_attribute_group = {
> diff --git a/tools/testing/cxl/test/cxl.c b/tools/testing/cxl/test/cxl.c
> index 40ed567952e6..cd2f20f2707f 100644
> --- a/tools/testing/cxl/test/cxl.c
> +++ b/tools/testing/cxl/test/cxl.c
> @@ -583,6 +583,7 @@ static __init int cxl_test_init(void)
> if (!pdev)
> goto err_mem;
> pdev->dev.parent = &port->dev;
> + set_dev_node(&pdev->dev, i % 2);
>
> rc = platform_device_add(pdev);
> if (rc) {
>
