From: Alison Schofield <alison.schofield@intel.com>
To: Dave Jiang <dave.jiang@intel.com>
Cc: linux-cxl@vger.kernel.org, linux-acpi@vger.kernel.org,
Dan Williams <dan.j.williams@intel.com>,
ira.weiny@intel.com, vishal.l.verma@intel.com, rafael@kernel.org,
lukas@wunner.de
Subject: Re: [PATCH v2 20/21] cxl: Export sysfs attributes for memory device QTG ID
Date: Tue, 28 Mar 2023 18:27:16 -0700 [thread overview]
Message-ID: <ZCOT9DS9/PhVGS4R@aschofie-mobl2> (raw)
In-Reply-To: <167995356611.2857312.4634198260468536572.stgit@djiang5-mobl3>
On Mon, Mar 27, 2023 at 02:46:06PM -0700, Dave Jiang wrote:
> Export qtg_id sysfs attributes for the CXL memory device. The QTG ID
> should show up as /sys/bus/cxl/devices/memX/qtg_id. The QTG ID is
> retrieved via _DSM after supplying the caluclated bandwidth and latency
calculated
> for the entire CXL path from device to the CPU. This ID is used to match
> up to the root decoder QTG ID to determine which CFMWS the memory range
> of a hotplugged CXL mem device should be assigned under.
>
> While there may be multiple DSMAS exported by the device CDAT, the driver
> will only expose the first QTG ID in sysfs for now. In the future when
> multiple QTG IDs are necessary, they can be exposed. [1]
>
> [1]: https://lore.kernel.org/linux-cxl/167571650007.587790.10040913293130712882.stgit@djiang5-mobl3.local/T/#md2a47b1ead3e1ba08f50eab29a4af1aed1d215ab
>
> Suggested-by: Dan Williams <dan.j.williams@intel.com>
> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
> ---
> Documentation/ABI/testing/sysfs-bus-cxl | 11 +++++++++++
> drivers/cxl/core/memdev.c | 15 +++++++++++++++
> 2 files changed, 26 insertions(+)
>
> diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl
> index 471ac9a37078..a018f0a21aca 100644
> --- a/Documentation/ABI/testing/sysfs-bus-cxl
> +++ b/Documentation/ABI/testing/sysfs-bus-cxl
> @@ -58,6 +58,17 @@ Description:
> affinity for this device.
>
>
> +What: /sys/bus/cxl/devices/memX/qtg_id
> +Date: March, 2024
> +KernelVersion: v6.4
> +Contact: linux-cxl@vger.kernel.org
> +Description:
> + (RO) Show the first QoS Throttling Group ID for the device.
> + The ID is used to match against the CFMWS (root decoder)
> + QTG ID so that the memory range under a hot-plugged device
> + is assigned under the appropriate CFMWS.
Some of the language in the cover letter seemed more descriptive, but
I guess it's a bit squishy to me. (ie. 'some guidance' and 'appropriate')
Would a spec link be useful here?
Alison
> +
> +
> 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 d2605fc39240..974eff833edd 100644
> --- a/drivers/cxl/core/memdev.c
> +++ b/drivers/cxl/core/memdev.c
> @@ -106,12 +106,27 @@ static ssize_t numa_node_show(struct device *dev, struct device_attribute *attr,
> }
> static DEVICE_ATTR_RO(numa_node);
>
> +static ssize_t qtg_id_show(struct device *dev, struct device_attribute *attr,
> + char *buf)
> +{
> + struct cxl_memdev *cxlmd = to_cxl_memdev(dev);
> + struct qos_prop_entry *qos;
> +
> + if (list_empty(&cxlmd->qos_list))
> + return 0;
> +
> + qos = list_first_entry(&cxlmd->qos_list, struct qos_prop_entry, list);
> + return sysfs_emit(buf, "%u\n", qos->qtg_id);
> +}
> +static DEVICE_ATTR_RO(qtg_id);
> +
> 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,
> + &dev_attr_qtg_id.attr,
> NULL,
> };
>
>
>
next prev parent reply other threads:[~2023-03-29 1:27 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-27 21:44 [PATCH v2 00/21] cxl: Add support for QTG ID retrieval for CXL subsystem Dave Jiang
2023-03-27 21:44 ` [PATCH v2 01/21] cxl: Export QTG ids from CFMWS to sysfs Dave Jiang
2023-03-29 23:57 ` Ira Weiny
2023-03-27 21:44 ` [PATCH v2 02/21] cxl: Add checksum verification to CDAT from CXL Dave Jiang
2023-03-29 0:03 ` Alison Schofield
2023-03-29 0:21 ` Dave Jiang
2023-03-30 0:09 ` Ira Weiny
2023-03-27 21:44 ` [PATCH v2 03/21] cxl: Add support for reading CXL switch CDAT table Dave Jiang
2023-03-30 0:19 ` Ira Weiny
2023-03-27 21:44 ` [PATCH v2 04/21] cxl: Add common helpers for cdat parsing Dave Jiang
2023-03-27 21:44 ` [PATCH v2 05/21] cxl: Add callback to parse the DSMAS subtables from CDAT Dave Jiang
2023-03-29 0:20 ` Alison Schofield
2023-03-29 20:41 ` Dave Jiang
2023-03-30 15:43 ` Dave Jiang
2023-03-27 21:44 ` [PATCH v2 06/21] cxl: Add callback to parse the DSLBIS subtable " Dave Jiang
2023-03-29 0:44 ` Alison Schofield
2023-03-29 20:59 ` Dave Jiang
2023-03-29 21:59 ` Alison Schofield
2023-03-27 21:44 ` [PATCH v2 07/21] cxl: Add callback to parse the SSLBIS " Dave Jiang
2023-03-27 21:44 ` [PATCH v2 08/21] cxl: Add support for _DSM Function for retrieving QTG ID Dave Jiang
2023-03-27 21:44 ` [PATCH v2 09/21] cxl: Add helper function to retrieve ACPI handle of CXL root device Dave Jiang
2023-03-27 21:45 ` [PATCH v2 10/21] cxl: Add helpers to calculate pci latency for the CXL device Dave Jiang
2023-03-27 21:45 ` [PATCH v2 11/21] cxl: Add helper function that calculates QoS values for switches Dave Jiang
2023-03-27 21:45 ` [PATCH v2 12/21] cxl: Add helper function that calculate QoS values for PCI path Dave Jiang
2023-03-27 21:45 ` [PATCH v2 13/21] ACPI: NUMA: Add genport target allocation to the HMAT parsing Dave Jiang
2023-03-27 21:45 ` [PATCH v2 14/21] ACPI: NUMA: Add helper function to retrieve the performance attributes Dave Jiang
2023-03-27 21:45 ` [PATCH v2 15/21] cxl: Add helper function to retrieve generic port QoS Dave Jiang
2023-03-27 21:45 ` [PATCH v2 16/21] cxl: Add latency and bandwidth calculations for the CXL path Dave Jiang
2023-03-27 21:45 ` [PATCH v2 17/21] cxl: Wait Memory_Info_Valid before access memory related info Dave Jiang
2023-03-27 21:45 ` [PATCH v2 18/21] cxl: Move identify and partition query from pci probe to port probe Dave Jiang
2023-03-27 21:46 ` [PATCH v2 19/21] cxl: Store QTG IDs and related info to the CXL memory device context Dave Jiang
2023-03-27 21:46 ` [PATCH v2 20/21] cxl: Export sysfs attributes for memory device QTG ID Dave Jiang
2023-03-29 1:27 ` Alison Schofield [this message]
2023-03-29 21:44 ` Dave Jiang
2023-03-29 21:55 ` Dan Williams
2023-03-29 22:02 ` Dave Jiang
2023-03-27 21:46 ` [PATCH v2 21/21] cxl/mem: Add debugfs output for QTG related data Dave Jiang
2023-03-29 1:13 ` Alison Schofield
2023-03-29 21:49 ` Dave Jiang
2023-03-28 17:45 ` [PATCH v2 00/21] cxl: Add support for QTG ID retrieval for CXL subsystem Dave Jiang
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