* Re: [PATCH v3 1/4] drm/ras: Introduce the DRM RAS infrastructure over generic netlink
2025-12-05 8:39 ` [PATCH v3 1/4] drm/ras: Introduce the DRM RAS infrastructure over generic netlink Riana Tauro
@ 2025-12-09 21:35 ` Rodrigo Vivi
0 siblings, 0 replies; 2+ messages in thread
From: Rodrigo Vivi @ 2025-12-09 21:35 UTC (permalink / raw)
To: Riana Tauro, Jakub Kicinski
Cc: intel-xe, dri-devel, aravind.iddamsetty, anshuman.gupta,
joonas.lahtinen, lukas, simona.vetter, airlied, pratik.bari,
joshua.santosh.ranjan, ashwin.kumar.kulkarni, shubham.kumar,
Zack McKevitt, Lijo Lazar, Hawking Zhang, Jakub Kicinski,
David S. Miller, Paolo Abeni, Eric Dumazet, netdev
On Fri, Dec 05, 2025 at 02:09:33PM +0530, Riana Tauro wrote:
> From: Rodrigo Vivi <rodrigo.vivi@intel.com>
>
> Introduces the DRM RAS infrastructure over generic netlink.
>
> The new interface allows drivers to expose RAS nodes and their
> associated error counters to userspace in a structured and extensible
> way. Each drm_ras node can register its own set of error counters, which
> are then discoverable and queryable through netlink operations. This
> lays the groundwork for reporting and managing hardware error states
> in a unified manner across different DRM drivers.
>
> Currently is only supports error-counter nodes. But it can be
> extended later.
>
> The registration is also no tied to any drm node, so it can be
> used by accel devices as well.
>
> It uses the new and mandatory YAML description format stored in
> Documentation/netlink/specs/. This forces a single generic netlink
> family namespace for the entire drm: "drm-ras".
> But multiple-endpoints are supported within the single family.
>
> Any modification to this API needs to be applied to
> Documentation/netlink/specs/drm_ras.yaml before regenerating the
> code:
>
> $ tools/net/ynl/pyynl/ynl_gen_c.py --spec \
> Documentation/netlink/specs/drm_ras.yaml --mode uapi --header \
> > include/uapi/drm/drm_ras.h
>
> $ tools/net/ynl/pyynl/ynl_gen_c.py --spec \
> Documentation/netlink/specs/drm_ras.yaml --mode kernel --header \
> > include/drm/drm_ras_nl.h
>
> $ tools/net/ynl/pyynl/ynl_gen_c.py --spec \
> Documentation/netlink/specs/drm_ras.yaml --mode kernel --source \
> > drivers/gpu/drm/drm_ras_nl.c
>
> Cc: Zack McKevitt <zachary.mckevitt@oss.qualcomm.com>
> Cc: Lukas Wunner <lukas@wunner.de>
> Cc: Lijo Lazar <lijo.lazar@amd.com>
> Cc: Hawking Zhang <Hawking.Zhang@amd.com>
> Cc: Jakub Kicinski <kuba@kernel.org>
> Cc: David S. Miller <davem@davemloft.net>
> Cc: Paolo Abeni <pabeni@redhat.com>
> Cc: Eric Dumazet <edumazet@google.com>
> Cc: netdev@vger.kernel.org
> Co-developed-by: Aravind Iddamsetty <aravind.iddamsetty@linux.intel.com>
> Signed-off-by: Aravind Iddamsetty <aravind.iddamsetty@linux.intel.com>
> Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
> Signed-off-by: Riana Tauro <riana.tauro@intel.com>
> ---
> v2: fix doc and memory leak
> use xe_for_each_start
> use standard genlmsg_iput (Jakub Kicinski)
>
> v3: add documentation to index
> modify documentation to mention uAPI requirements (Rodrigo)
> ---
> Documentation/gpu/drm-ras.rst | 109 +++++++
> Documentation/gpu/index.rst | 1 +
> Documentation/netlink/specs/drm_ras.yaml | 130 +++++++++
> drivers/gpu/drm/Kconfig | 9 +
> drivers/gpu/drm/Makefile | 1 +
> drivers/gpu/drm/drm_drv.c | 6 +
> drivers/gpu/drm/drm_ras.c | 351 +++++++++++++++++++++++
> drivers/gpu/drm/drm_ras_genl_family.c | 42 +++
> drivers/gpu/drm/drm_ras_nl.c | 54 ++++
> include/drm/drm_ras.h | 76 +++++
> include/drm/drm_ras_genl_family.h | 17 ++
> include/drm/drm_ras_nl.h | 24 ++
> include/uapi/drm/drm_ras.h | 49 ++++
> 13 files changed, 869 insertions(+)
> create mode 100644 Documentation/gpu/drm-ras.rst
> create mode 100644 Documentation/netlink/specs/drm_ras.yaml
> create mode 100644 drivers/gpu/drm/drm_ras.c
> create mode 100644 drivers/gpu/drm/drm_ras_genl_family.c
> create mode 100644 drivers/gpu/drm/drm_ras_nl.c
> create mode 100644 include/drm/drm_ras.h
> create mode 100644 include/drm/drm_ras_genl_family.h
> create mode 100644 include/drm/drm_ras_nl.h
> create mode 100644 include/uapi/drm/drm_ras.h
>
> diff --git a/Documentation/gpu/drm-ras.rst b/Documentation/gpu/drm-ras.rst
> new file mode 100644
> index 000000000000..cec60cf5d17d
> --- /dev/null
> +++ b/Documentation/gpu/drm-ras.rst
> @@ -0,0 +1,109 @@
> +.. SPDX-License-Identifier: GPL-2.0+
> +
> +============================
> +DRM RAS over Generic Netlink
> +============================
> +
> +The DRM RAS (Reliability, Availability, Serviceability) interface provides a
> +standardized way for GPU/accelerator drivers to expose error counters and
> +other reliability nodes to user space via Generic Netlink. This allows
> +diagnostic tools, monitoring daemons, or test infrastructure to query hardware
> +health in a uniform way across different DRM drivers.
> +
> +Key Goals:
> +
> +* Provide a standardized RAS solution for GPU and accelerator drivers, enabling
> + data center monitoring and reliability operations.
> +* Implement a single drm-ras Generic Netlink family to meet modern Netlink YAML
> + specifications and centralize all RAS-related communication in one namespace.
> +* Support a basic error counter interface, addressing the immediate, essential
> + monitoring needs.
> +* Offer a flexible, future-proof interface that can be extended to support
> + additional types of RAS data in the future.
> +* Allow multiple nodes per driver, enabling drivers to register separate
> + nodes for different IP blocks, sub-blocks, or other logical subdivisions
> + as applicable.
> +
> +Nodes
> +=====
> +
> +Nodes are logical abstractions representing an error source or block within
> +the device. Currently, only error counter nodes is supported.
> +
> +Drivers are responsible for registering and unregistering nodes via the
> +`drm_ras_node_register()` and `drm_ras_node_unregister()` APIs.
> +
> +Node Management
> +-------------------
> +
> +.. kernel-doc:: drivers/gpu/drm/drm_ras.c
> + :doc: DRM RAS Node Management
> +.. kernel-doc:: drivers/gpu/drm/drm_ras.c
> + :internal:
> +
> +Generic Netlink Usage
> +=====================
> +
> +The interface is implemented as a Generic Netlink family named ``drm-ras``.
> +User space tools can:
> +
> +* List registered nodes with the ``get-nodes`` command.
> +* List all error counters in an node with the ``get-error-counters`` command.
> +* Query error counters using the ``query-error-counter`` command.
> +
> +YAML-based Interface
> +--------------------
> +
> +The interface is described in a YAML specification:
> +
> +:ref:`Documentation/netlink/specs/drm_ras.yaml`
> +
> +This YAML is used to auto-generate user space bindings via
> +``tools/net/ynl/pyynl/ynl_gen_c.py``, and drives the structure of netlink
> +attributes and operations.
> +
> +Usage Notes
> +-----------
> +
> +* User space must first enumerate nodes to obtain their IDs.
> +* Node IDs or Node names can be used for all further queries, such as error counters.
> +* Error counters can be queried by either the Error ID or Error name.
> +* Query Parameters should be defined as part of the uAPI to ensure user interface stability.
> +* The interface supports future extension by adding new node types and
> + additional attributes.
> +
> +Example: List nodes using ynl
> +
> +.. code-block:: bash
> +
> + sudo ynl --family drm_ras --dump list-nodes
> + [{'device-name': '0000:03:00.0',
> + 'node-id': 0,
> + 'node-name': 'correctable-errors',
> + 'node-type': 'error-counter'},
> + {'device-name': '0000:03:00.0',
> + 'node-id': 1,
> + 'node-name': 'nonfatal-errors',
> + 'node-type': 'error-counter'},
> + {'device-name': '0000:03:00.0',
> + 'node-id': 2,
> + 'node-name': 'fatal-errors',
> + 'node-type': 'error-counter'}]
> +
> +Example: List all error counters using ynl
> +
> +.. code-block:: bash
> +
> +
> + sudo ynl --family drm_ras --dump get-error-counters --json '{"node-id":1}'
> + [{'error-id': 1, 'error-name': 'error_name_1', 'error-value': 0},
> + {'error-id': 2, 'error-name': 'error_name_2', 'error-value': 0}]
> +
> +
> +Example: Query an error counter for a given node
> +
> +.. code-block:: bash
> +
> + sudo ynl --family drm_ras --do query-error-counter --json '{"node-id":2, "error-id":1}'
> + {'error-id': 1, 'error-name': 'error_name_1', 'error-value': 0}
> +
> diff --git a/Documentation/gpu/index.rst b/Documentation/gpu/index.rst
> index 7dcb15850afd..60c73fdcfeed 100644
> --- a/Documentation/gpu/index.rst
> +++ b/Documentation/gpu/index.rst
> @@ -9,6 +9,7 @@ GPU Driver Developer's Guide
> drm-mm
> drm-kms
> drm-kms-helpers
> + drm-ras
> drm-uapi
> drm-usage-stats
> driver-uapi
> diff --git a/Documentation/netlink/specs/drm_ras.yaml b/Documentation/netlink/specs/drm_ras.yaml
> new file mode 100644
> index 000000000000..be0e379c5bc9
> --- /dev/null
> +++ b/Documentation/netlink/specs/drm_ras.yaml
> @@ -0,0 +1,130 @@
> +# SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)
> +---
> +name: drm-ras
> +protocol: genetlink
> +uapi-header: drm/drm_ras.h
> +
> +doc: >-
> + DRM RAS (Reliability, Availability, Serviceability) over Generic Netlink.
> + Provides a standardized mechanism for DRM drivers to register "nodes"
> + representing hardware/software components capable of reporting error counters.
> + Userspace tools can query the list of nodes or individual error counters
> + via the Generic Netlink interface.
> +
> +definitions:
> + -
> + type: enum
> + name: node-type
> + value-start: 1
> + entries: [error-counter]
> + doc: >-
> + Type of the node. Currently, only error-counter nodes are
> + supported, which expose reliability counters for a hardware/software
> + component.
> +
> +attribute-sets:
> + -
> + name: node-attrs
> + attributes:
> + -
> + name: node-id
> + type: u32
> + doc: >-
> + Unique identifier for the node.
> + Assigned dynamically by the DRM RAS core upon registration.
> + -
> + name: device-name
> + type: string
> + doc: >-
> + Device name chosen by the driver at registration.
> + Can be a PCI BDF, UUID, or module name if unique.
> + -
> + name: node-name
> + type: string
> + doc: >-
> + Node name chosen by the driver at registration.
> + Can be an IP block name, or any name that identifies the
> + RAS node inside the device.
> + -
> + name: node-type
> + type: u32
> + doc: Type of this node, identifying its function.
> + enum: node-type
> + -
> + name: error-counter-attrs
> + attributes:
> + -
> + name: node-id
> + type: u32
> + doc: Node ID targeted by this error counter operation.
> + -
> + name: error-id
> + type: u32
> + doc: Unique identifier for a specific error counter within an node.
> + -
> + name: error-name
> + type: string
> + doc: Name of the error.
> + -
> + name: error-value
> + type: u32
> + doc: Current value of the requested error counter.
> +
> +operations:
> + list:
> + -
> + name: list-nodes
> + doc: >-
> + Retrieve the full list of currently registered DRM RAS nodes.
> + Each node includes its dynamically assigned ID, name, and type.
> + **Important:** User space must call this operation first to obtain
> + the node IDs. These IDs are required for all subsequent
> + operations on nodes, such as querying error counters.
> + attribute-set: node-attrs
> + flags: [admin-perm]
> + dump:
> + reply:
> + attributes:
> + - node-id
> + - device-name
> + - node-name
> + - node-type
> + -
> + name: get-error-counters
> + doc: >-
> + Retrieve the full list of error counters for a given node.
> + The response include the id, the name, and even the current
> + value of each counter.
> + attribute-set: error-counter-attrs
> + flags: [admin-perm]
> + dump:
> + request:
> + attributes:
> + - node-id
> + reply:
> + attributes:
> + - error-id
> + - error-name
> + - error-value
> + -
> + name: query-error-counter
> + doc: >-
> + Query the information of a specific error counter for a given node.
> + Users must provide the node ID and the error counter ID.
> + The response contains the id, the name, and the current value
> + of the counter.
> + attribute-set: error-counter-attrs
> + flags: [admin-perm]
> + do:
> + request:
> + attributes:
> + - node-id
> + - error-id
> + reply:
> + attributes:
> + - error-id
> + - error-name
> + - error-value
> +
> +kernel-family:
> + headers: ["drm/drm_ras_nl.h"]
> diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
> index 7e6bc0b3a589..5cfb23b80441 100644
> --- a/drivers/gpu/drm/Kconfig
> +++ b/drivers/gpu/drm/Kconfig
> @@ -130,6 +130,15 @@ config DRM_PANIC_SCREEN_QR_VERSION
> Smaller QR code are easier to read, but will contain less debugging
> data. Default is 40.
>
> +config DRM_RAS
> + bool "DRM RAS support"
> + depends on DRM
> + help
> + Enables the DRM RAS (Reliability, Availability and Serviceability)
> + support for DRM drivers. This provides a Generic Netlink interface
> + for error reporting and queries.
> + If in doubt, say "N".
> +
> config DRM_DEBUG_DP_MST_TOPOLOGY_REFS
> bool "Enable refcount backtrace history in the DP MST helpers"
> depends on STACKTRACE_SUPPORT
> diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
> index 4b3f3ad5058a..cd19573b2d9f 100644
> --- a/drivers/gpu/drm/Makefile
> +++ b/drivers/gpu/drm/Makefile
> @@ -95,6 +95,7 @@ drm-$(CONFIG_DRM_ACCEL) += ../../accel/drm_accel.o
> drm-$(CONFIG_DRM_PANIC) += drm_panic.o
> drm-$(CONFIG_DRM_DRAW) += drm_draw.o
> drm-$(CONFIG_DRM_PANIC_SCREEN_QR_CODE) += drm_panic_qr.o
> +drm-$(CONFIG_DRM_RAS) += drm_ras.o drm_ras_nl.o drm_ras_genl_family.o
> obj-$(CONFIG_DRM) += drm.o
>
> obj-$(CONFIG_DRM_PANEL_ORIENTATION_QUIRKS) += drm_panel_orientation_quirks.o
> diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
> index 2915118436ce..6b965c3d3307 100644
> --- a/drivers/gpu/drm/drm_drv.c
> +++ b/drivers/gpu/drm/drm_drv.c
> @@ -53,6 +53,7 @@
> #include <drm/drm_panic.h>
> #include <drm/drm_print.h>
> #include <drm/drm_privacy_screen_machine.h>
> +#include <drm/drm_ras_genl_family.h>
>
> #include "drm_crtc_internal.h"
> #include "drm_internal.h"
> @@ -1223,6 +1224,7 @@ static const struct file_operations drm_stub_fops = {
>
> static void drm_core_exit(void)
> {
> + drm_ras_genl_family_unregister();
> drm_privacy_screen_lookup_exit();
> drm_panic_exit();
> accel_core_exit();
> @@ -1261,6 +1263,10 @@ static int __init drm_core_init(void)
>
> drm_privacy_screen_lookup_init();
>
> + ret = drm_ras_genl_family_register();
> + if (ret < 0)
> + goto error;
> +
> drm_core_init_complete = true;
>
> DRM_DEBUG("Initialized\n");
> diff --git a/drivers/gpu/drm/drm_ras.c b/drivers/gpu/drm/drm_ras.c
> new file mode 100644
> index 000000000000..32f3897ce580
> --- /dev/null
> +++ b/drivers/gpu/drm/drm_ras.c
> @@ -0,0 +1,351 @@
> +// SPDX-License-Identifier: MIT
> +/*
> + * Copyright © 2025 Intel Corporation
> + */
> +
> +#include <linux/module.h>
> +#include <linux/kernel.h>
> +#include <linux/netdevice.h>
> +#include <linux/xarray.h>
> +#include <net/genetlink.h>
> +
> +#include <drm/drm_ras.h>
> +
> +/**
> + * DOC: DRM RAS Node Management
> + *
> + * This module provides the infrastructure to manage RAS (Reliability,
> + * Availability, and Serviceability) nodes for DRM drivers. Each
> + * DRM driver may register one or more RAS nodes, which represent
> + * logical components capable of reporting error counters and other
> + * reliability metrics.
> + *
> + * The nodes are stored in a global xarray `drm_ras_xa` to allow
> + * efficient lookup by ID. Nodes can be registered or unregistered
> + * dynamically at runtime.
> + *
> + * A Generic Netlink family `drm_ras` exposes two main operations to
> + * userspace:
> + *
> + * 1. LIST_NODES: Dump all currently registered RAS nodes.
> + * The user receives an array of node IDs, names, and types.
> + *
> + * 2. GET_ERROR_COUNTERS: Dump all error counters of a given node.
> + * The user receives an array of error IDs, names, and current value.
> + *
> + * 3. QUERY_ERROR_COUNTER: Query a specific error counter for a given node.
> + * Userspace must provide the node ID and the counter ID, and
> + * receives the ID, the error name, and its current value.
> + *
> + * Node registration:
> + * - drm_ras_node_register(): Registers a new node and assigns
> + * it a unique ID in the xarray.
> + * - drm_ras_node_unregister(): Removes a previously registered
> + * node from the xarray.
> + *
> + * Node type:
> + * - ERROR_COUNTER:
> + * + Currently, only error counters are supported.
> + * + The driver must implement the query_error_counter() callback to provide
> + * the name and the value of the error counter.
> + * + The driver must provide a error_counter_range.last value informing the
> + * last valid error ID.
> + * + The driver can provide a error_counter_range.first value informing the
> + * frst valid error ID.
> + * + The error counters in the driver doesn't need to be contiguous, but the
> + * driver must return -ENOENT to the query_error_counter as an indication
> + * that the ID should be skipped and not listed in the netlink API.
> + *
> + * Netlink handlers:
> + * - drm_ras_nl_list_nodes_dumpit(): Implements the LIST_NODES
> + * operation, iterating over the xarray.
> + * - drm_ras_nl_get_error_counters_dumpit(): Implements the GET_ERROR_COUNTERS
> + * operation, iterating over the know valid error_counter_range.
> + * - drm_ras_nl_query_error_counter_doit(): Implements the QUERY_ERROR_COUNTER
> + * operation, fetching a counter value from a specific node.
> + */
> +
> +static DEFINE_XARRAY_ALLOC(drm_ras_xa);
> +
> +/*
> + * The netlink callback context carries dump state across multiple dumpit calls
> + */
> +struct drm_ras_ctx {
> + /* Which xarray id to restart the dump from */
> + unsigned long restart;
> +};
> +
> +/**
> + * drm_ras_nl_list_nodes_dumpit() - Dump all registered RAS nodes
> + * @skb: Netlink message buffer
> + * @cb: Callback context for multi-part dumps
> + *
> + * Iterates over all registered RAS nodes in the global xarray and appends
> + * their attributes (ID, name, type) to the given netlink message buffer.
> + * Uses @cb->ctx to track progress in case the message buffer fills up, allowing
> + * multi-part dump support. On buffer overflow, updates the context to resume
> + * from the last node on the next invocation.
> + *
> + * Return: 0 if all nodes fit in @skb, number of bytes added to @skb if
> + * the buffer filled up (requires multi-part continuation), or
> + * a negative error code on failure.
> + */
> +int drm_ras_nl_list_nodes_dumpit(struct sk_buff *skb,
> + struct netlink_callback *cb)
> +{
> + const struct genl_info *info = genl_info_dump(cb);
> + struct drm_ras_ctx *ctx = (void *)cb->ctx;
> + struct drm_ras_node *node;
> + struct nlattr *hdr;
> + unsigned long id;
> + int ret;
> +
> + xa_for_each_start(&drm_ras_xa, id, node, ctx->restart) {
> + hdr = genlmsg_iput(skb, info);
> + if (!hdr) {
> + ret = -EMSGSIZE;
> + break;
> + }
> +
> + ret = nla_put_u32(skb, DRM_RAS_A_NODE_ATTRS_NODE_ID, node->id);
> + if (ret) {
> + genlmsg_cancel(skb, hdr);
> + break;
> + }
> +
> + ret = nla_put_string(skb, DRM_RAS_A_NODE_ATTRS_DEVICE_NAME,
> + node->device_name);
> + if (ret) {
> + genlmsg_cancel(skb, hdr);
> + break;
> + }
> +
> + ret = nla_put_string(skb, DRM_RAS_A_NODE_ATTRS_NODE_NAME,
> + node->node_name);
> + if (ret) {
> + genlmsg_cancel(skb, hdr);
> + break;
> + }
> +
> + ret = nla_put_u32(skb, DRM_RAS_A_NODE_ATTRS_NODE_TYPE,
> + node->type);
> + if (ret) {
> + genlmsg_cancel(skb, hdr);
> + break;
> + }
> +
> + genlmsg_end(skb, hdr);
> + }
> +
> + if (ret == -EMSGSIZE)
> + ctx->restart = id;
Jakub had mentioned that we don't need this special handling
of the -EMSGSIZE, but then I'm not sure what to use in the
xa_for_each_start, so
Cc: Jakub Kicinski <kuba@kernel.org>
to ensure that we are in the right path here.
Riana, thank you so much for picking up this and addressing all
the comments. Patch looks good to me.
Thanks,
Rodrigo.
> +
> + return ret;
> +}
> +
> +static int get_node_error_counter(u32 node_id, u32 error_id,
> + const char **name, u32 *value)
> +{
> + struct drm_ras_node *node;
> +
> + node = xa_load(&drm_ras_xa, node_id);
> + if (!node || !node->query_error_counter)
> + return -ENOENT;
> +
> + if (error_id < node->error_counter_range.first ||
> + error_id > node->error_counter_range.last)
> + return -EINVAL;
> +
> + return node->query_error_counter(node, error_id, name, value);
> +}
> +
> +static int msg_reply_value(struct sk_buff *msg, u32 error_id,
> + const char *error_name, u32 value)
> +{
> + int ret;
> +
> + ret = nla_put_u32(msg, DRM_RAS_A_ERROR_COUNTER_ATTRS_ERROR_ID, error_id);
> + if (ret)
> + return ret;
> +
> + ret = nla_put_string(msg, DRM_RAS_A_ERROR_COUNTER_ATTRS_ERROR_NAME,
> + error_name);
> + if (ret)
> + return ret;
> +
> + return nla_put_u32(msg, DRM_RAS_A_ERROR_COUNTER_ATTRS_ERROR_VALUE,
> + value);
> +}
> +
> +static int doit_reply_value(struct genl_info *info, u32 node_id,
> + u32 error_id)
> +{
> + struct sk_buff *msg;
> + struct nlattr *hdr;
> + const char *error_name;
> + u32 value;
> + int ret;
> +
> + msg = genlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
> + if (!msg)
> + return -ENOMEM;
> +
> + hdr = genlmsg_iput(msg, info);
> + if (!hdr) {
> + nlmsg_free(msg);
> + return -EMSGSIZE;
> + }
> +
> + ret = get_node_error_counter(node_id, error_id,
> + &error_name, &value);
> + if (ret)
> + return ret;
> +
> + ret = msg_reply_value(msg, error_id, error_name, value);
> + if (ret) {
> + genlmsg_cancel(msg, hdr);
> + nlmsg_free(msg);
> + return ret;
> + }
> +
> + genlmsg_end(msg, hdr);
> +
> + return genlmsg_reply(msg, info);
> +}
> +
> +/**
> + * drm_ras_nl_get_error_counters_dumpit() - Dump all Error Counters
> + * @skb: Netlink message buffer
> + * @cb: Callback context for multi-part dumps
> + *
> + * Iterates over all error counters in a given Node and appends
> + * their attributes (ID, name, value) to the given netlink message buffer.
> + * Uses @cb->ctx to track progress in case the message buffer fills up, allowing
> + * multi-part dump support. On buffer overflow, updates the context to resume
> + * from the last node on the next invocation.
> + *
> + * Return: 0 if all errors fit in @skb, number of bytes added to @skb if
> + * the buffer filled up (requires multi-part continuation), or
> + * a negative error code on failure.
> + */
> +int drm_ras_nl_get_error_counters_dumpit(struct sk_buff *skb,
> + struct netlink_callback *cb)
> +{
> + const struct genl_info *info = genl_info_dump(cb);
> + struct drm_ras_ctx *ctx = (void *)cb->ctx;
> + struct drm_ras_node *node;
> + struct nlattr *hdr;
> + const char *error_name;
> + u32 node_id, error_id, value;
> + int ret;
> +
> + if (!info->attrs || !info->attrs[DRM_RAS_A_ERROR_COUNTER_ATTRS_NODE_ID])
> + return -EINVAL;
> +
> + node_id = nla_get_u32(info->attrs[DRM_RAS_A_ERROR_COUNTER_ATTRS_NODE_ID]);
> +
> + node = xa_load(&drm_ras_xa, node_id);
> + if (!node)
> + return -ENOENT;
> +
> + for (error_id = max(node->error_counter_range.first, ctx->restart);
> + error_id <= node->error_counter_range.last;
> + error_id++) {
> + ret = get_node_error_counter(node_id, error_id,
> + &error_name, &value);
> + /*
> + * For non-contiguous range, driver return -ENOENT as indication
> + * to skip this ID when listing all errors.
> + */
> + if (ret == -ENOENT)
> + continue;
> + if (ret)
> + return ret;
> +
> + hdr = genlmsg_iput(skb, info);
> +
> + if (!hdr) {
> + ret = -EMSGSIZE;
> + break;
> + }
> +
> + ret = msg_reply_value(skb, error_id, error_name, value);
> + if (ret) {
> + genlmsg_cancel(skb, hdr);
> + break;
> + }
> +
> + genlmsg_end(skb, hdr);
> + }
> +
> + if (ret == -EMSGSIZE)
> + ctx->restart = error_id;
> +
> + return ret;
> +}
> +
> +/**
> + * drm_ras_nl_query_error_counter_doit() - Query an error counter of an node
> + * @skb: Netlink message buffer
> + * @info: Generic Netlink info containing attributes of the request
> + *
> + * Extracts the node ID and error ID from the netlink attributes and
> + * retrieves the current value of the corresponding error counter. Sends the
> + * result back to the requesting user via the standard Genl reply.
> + *
> + * Return: 0 on success, or negative errno on failure.
> + */
> +int drm_ras_nl_query_error_counter_doit(struct sk_buff *skb,
> + struct genl_info *info)
> +{
> + u32 node_id, error_id;
> +
> + if (!info->attrs ||
> + !info->attrs[DRM_RAS_A_ERROR_COUNTER_ATTRS_NODE_ID] ||
> + !info->attrs[DRM_RAS_A_ERROR_COUNTER_ATTRS_ERROR_ID])
> + return -EINVAL;
> +
> + node_id = nla_get_u32(info->attrs[DRM_RAS_A_ERROR_COUNTER_ATTRS_NODE_ID]);
> + error_id = nla_get_u32(info->attrs[DRM_RAS_A_ERROR_COUNTER_ATTRS_ERROR_ID]);
> +
> + return doit_reply_value(info, node_id, error_id);
> +}
> +
> +/**
> + * drm_ras_node_register() - Register a new RAS node
> + * @node: Node structure to register
> + *
> + * Adds the given RAS node to the global node xarray and assigns it
> + * a unique ID. Both @node->name and @node->type must be valid.
> + *
> + * Return: 0 on success, or negative errno on failure:
> + */
> +int drm_ras_node_register(struct drm_ras_node *node)
> +{
> + if (!node->device_name || !node->node_name)
> + return -EINVAL;
> +
> + /* Currently, only Error Counter Endpoinnts are supported */
> + if (node->type != DRM_RAS_NODE_TYPE_ERROR_COUNTER)
> + return -EINVAL;
> +
> + /* Mandatorty entries for Error Counter Node */
> + if (node->type == DRM_RAS_NODE_TYPE_ERROR_COUNTER &&
> + (!node->error_counter_range.last || !node->query_error_counter))
> + return -EINVAL;
> +
> + return xa_alloc(&drm_ras_xa, &node->id, node, xa_limit_32b, GFP_KERNEL);
> +}
> +EXPORT_SYMBOL(drm_ras_node_register);
> +
> +/**
> + * drm_ras_node_unregister() - Unregister a previously registered node
> + * @node: Node structure to unregister
> + *
> + * Removes the given node from the global node xarray using its ID.
> + */
> +void drm_ras_node_unregister(struct drm_ras_node *node)
> +{
> + xa_erase(&drm_ras_xa, node->id);
> +}
> +EXPORT_SYMBOL(drm_ras_node_unregister);
> diff --git a/drivers/gpu/drm/drm_ras_genl_family.c b/drivers/gpu/drm/drm_ras_genl_family.c
> new file mode 100644
> index 000000000000..2d818b8c3808
> --- /dev/null
> +++ b/drivers/gpu/drm/drm_ras_genl_family.c
> @@ -0,0 +1,42 @@
> +// SPDX-License-Identifier: MIT
> +/*
> + * Copyright © 2025 Intel Corporation
> + */
> +
> +#include <drm/drm_ras_genl_family.h>
> +#include <drm/drm_ras_nl.h>
> +
> +/* Track family registration so the drm_exit can be called at any time */
> +static bool registered;
> +
> +/**
> + * drm_ras_genl_family_register() - Register drm-ras genl family
> + *
> + * Only to be called one at drm_drv_init()
> + */
> +int drm_ras_genl_family_register(void)
> +{
> + int ret;
> +
> + registered = false;
> +
> + ret = genl_register_family(&drm_ras_nl_family);
> + if (ret)
> + return ret;
> +
> + registered = true;
> + return 0;
> +}
> +
> +/**
> + * drm_ras_genl_family_unregister() - Unregister drm-ras genl family
> + *
> + * To be called one at drm_drv_exit() at any moment, but only once.
> + */
> +void drm_ras_genl_family_unregister(void)
> +{
> + if (registered) {
> + genl_unregister_family(&drm_ras_nl_family);
> + registered = false;
> + }
> +}
> diff --git a/drivers/gpu/drm/drm_ras_nl.c b/drivers/gpu/drm/drm_ras_nl.c
> new file mode 100644
> index 000000000000..fcd1392410e4
> --- /dev/null
> +++ b/drivers/gpu/drm/drm_ras_nl.c
> @@ -0,0 +1,54 @@
> +// SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)
> +/* Do not edit directly, auto-generated from: */
> +/* Documentation/netlink/specs/drm_ras.yaml */
> +/* YNL-GEN kernel source */
> +
> +#include <net/netlink.h>
> +#include <net/genetlink.h>
> +
> +#include <uapi/drm/drm_ras.h>
> +#include <drm/drm_ras_nl.h>
> +
> +/* DRM_RAS_CMD_GET_ERROR_COUNTERS - dump */
> +static const struct nla_policy drm_ras_get_error_counters_nl_policy[DRM_RAS_A_ERROR_COUNTER_ATTRS_NODE_ID + 1] = {
> + [DRM_RAS_A_ERROR_COUNTER_ATTRS_NODE_ID] = { .type = NLA_U32, },
> +};
> +
> +/* DRM_RAS_CMD_QUERY_ERROR_COUNTER - do */
> +static const struct nla_policy drm_ras_query_error_counter_nl_policy[DRM_RAS_A_ERROR_COUNTER_ATTRS_ERROR_ID + 1] = {
> + [DRM_RAS_A_ERROR_COUNTER_ATTRS_NODE_ID] = { .type = NLA_U32, },
> + [DRM_RAS_A_ERROR_COUNTER_ATTRS_ERROR_ID] = { .type = NLA_U32, },
> +};
> +
> +/* Ops table for drm_ras */
> +static const struct genl_split_ops drm_ras_nl_ops[] = {
> + {
> + .cmd = DRM_RAS_CMD_LIST_NODES,
> + .dumpit = drm_ras_nl_list_nodes_dumpit,
> + .flags = GENL_ADMIN_PERM | GENL_CMD_CAP_DUMP,
> + },
> + {
> + .cmd = DRM_RAS_CMD_GET_ERROR_COUNTERS,
> + .dumpit = drm_ras_nl_get_error_counters_dumpit,
> + .policy = drm_ras_get_error_counters_nl_policy,
> + .maxattr = DRM_RAS_A_ERROR_COUNTER_ATTRS_NODE_ID,
> + .flags = GENL_ADMIN_PERM | GENL_CMD_CAP_DUMP,
> + },
> + {
> + .cmd = DRM_RAS_CMD_QUERY_ERROR_COUNTER,
> + .doit = drm_ras_nl_query_error_counter_doit,
> + .policy = drm_ras_query_error_counter_nl_policy,
> + .maxattr = DRM_RAS_A_ERROR_COUNTER_ATTRS_ERROR_ID,
> + .flags = GENL_ADMIN_PERM | GENL_CMD_CAP_DO,
> + },
> +};
> +
> +struct genl_family drm_ras_nl_family __ro_after_init = {
> + .name = DRM_RAS_FAMILY_NAME,
> + .version = DRM_RAS_FAMILY_VERSION,
> + .netnsok = true,
> + .parallel_ops = true,
> + .module = THIS_MODULE,
> + .split_ops = drm_ras_nl_ops,
> + .n_split_ops = ARRAY_SIZE(drm_ras_nl_ops),
> +};
> diff --git a/include/drm/drm_ras.h b/include/drm/drm_ras.h
> new file mode 100644
> index 000000000000..bba47a282ef8
> --- /dev/null
> +++ b/include/drm/drm_ras.h
> @@ -0,0 +1,76 @@
> +/* SPDX-License-Identifier: MIT */
> +/*
> + * Copyright © 2025 Intel Corporation
> + */
> +
> +#ifndef __DRM_RAS_H__
> +#define __DRM_RAS_H__
> +
> +#include "drm_ras_nl.h"
> +
> +/**
> + * struct drm_ras_node - A DRM RAS Node
> + */
> +struct drm_ras_node {
> + /** @id: Unique identifier for the node. Dynamically assigned. */
> + u32 id;
> + /**
> + * @device_name: Human-readable name of the device. Given by the driver.
> + */
> + const char *device_name;
> + /** @node_name: Human-readable name of the node. Given by the driver. */
> + const char *node_name;
> + /** @type: Type of the node (enum drm_ras_node_type). */
> + enum drm_ras_node_type type;
> +
> + /* Error-Counter Related Callback and Variables */
> +
> + /** @error_counter_range: Range of valid Error IDs for this node. */
> + struct {
> + /** @first: First valid Error ID. */
> + u32 first;
> + /** @last: Last valid Error ID. Mandatory entry. */
> + u32 last;
> + } error_counter_range;
> +
> + /**
> + * @query_error_counter:
> + *
> + * This callback is used by drm-ras to query a specific error counter.
> + * counters supported by this node. Used for input check and to
> + * iterate in all counters.
> + *
> + * Driver should expect query_error_counters() to be called with
> + * error_id from `error_counter_range.first` to
> + * `error_counter_range.last`.
> + *
> + * The @query_error_counter is a mandatory callback for
> + * error_counter_node.
> + *
> + * Returns: 0 on success,
> + * -ENOENT when error_id is not supported as an indication that
> + * drm_ras should silently skip this entry. Used for
> + * supporting non-contiguous error ranges.
> + * Driver is responsible for maintaining the list of
> + * supported error IDs in the range of first to last.
> + * Other negative values on errors that should terminate the
> + * netlink query.
> + */
> + int (*query_error_counter)(struct drm_ras_node *ep, u32 error_id,
> + const char **name, u32 *val);
> +
> + /** @priv: Driver private data */
> + void *priv;
> +};
> +
> +struct drm_device;
> +
> +#if IS_ENABLED(CONFIG_DRM_RAS)
> +int drm_ras_node_register(struct drm_ras_node *ep);
> +void drm_ras_node_unregister(struct drm_ras_node *ep);
> +#else
> +static inline int drm_ras_node_register(struct drm_ras_node *ep) { return 0; }
> +static inline void drm_ras_node_unregister(struct drm_ras_node *ep) { }
> +#endif
> +
> +#endif
> diff --git a/include/drm/drm_ras_genl_family.h b/include/drm/drm_ras_genl_family.h
> new file mode 100644
> index 000000000000..5931b53429f1
> --- /dev/null
> +++ b/include/drm/drm_ras_genl_family.h
> @@ -0,0 +1,17 @@
> +/* SPDX-License-Identifier: MIT */
> +/*
> + * Copyright © 2025 Intel Corporation
> + */
> +
> +#ifndef __DRM_RAS_GENL_FAMILY_H__
> +#define __DRM_RAS_GENL_FAMILY_H__
> +
> +#if IS_ENABLED(CONFIG_DRM_RAS)
> +int drm_ras_genl_family_register(void);
> +void drm_ras_genl_family_unregister(void);
> +#else
> +static inline int drm_ras_genl_family_register(void) { return 0; }
> +static inline void drm_ras_genl_family_unregister(void) { }
> +#endif
> +
> +#endif
> diff --git a/include/drm/drm_ras_nl.h b/include/drm/drm_ras_nl.h
> new file mode 100644
> index 000000000000..9613b7d9ffdb
> --- /dev/null
> +++ b/include/drm/drm_ras_nl.h
> @@ -0,0 +1,24 @@
> +/* SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) */
> +/* Do not edit directly, auto-generated from: */
> +/* Documentation/netlink/specs/drm_ras.yaml */
> +/* YNL-GEN kernel header */
> +
> +#ifndef _LINUX_DRM_RAS_GEN_H
> +#define _LINUX_DRM_RAS_GEN_H
> +
> +#include <net/netlink.h>
> +#include <net/genetlink.h>
> +
> +#include <uapi/drm/drm_ras.h>
> +#include <drm/drm_ras_nl.h>
> +
> +int drm_ras_nl_list_nodes_dumpit(struct sk_buff *skb,
> + struct netlink_callback *cb);
> +int drm_ras_nl_get_error_counters_dumpit(struct sk_buff *skb,
> + struct netlink_callback *cb);
> +int drm_ras_nl_query_error_counter_doit(struct sk_buff *skb,
> + struct genl_info *info);
> +
> +extern struct genl_family drm_ras_nl_family;
> +
> +#endif /* _LINUX_DRM_RAS_GEN_H */
> diff --git a/include/uapi/drm/drm_ras.h b/include/uapi/drm/drm_ras.h
> new file mode 100644
> index 000000000000..3415ba345ac8
> --- /dev/null
> +++ b/include/uapi/drm/drm_ras.h
> @@ -0,0 +1,49 @@
> +/* SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) */
> +/* Do not edit directly, auto-generated from: */
> +/* Documentation/netlink/specs/drm_ras.yaml */
> +/* YNL-GEN uapi header */
> +
> +#ifndef _UAPI_LINUX_DRM_RAS_H
> +#define _UAPI_LINUX_DRM_RAS_H
> +
> +#define DRM_RAS_FAMILY_NAME "drm-ras"
> +#define DRM_RAS_FAMILY_VERSION 1
> +
> +/*
> + * Type of the node. Currently, only error-counter nodes are supported, which
> + * expose reliability counters for a hardware/software component.
> + */
> +enum drm_ras_node_type {
> + DRM_RAS_NODE_TYPE_ERROR_COUNTER = 1,
> +};
> +
> +enum {
> + DRM_RAS_A_NODE_ATTRS_NODE_ID = 1,
> + DRM_RAS_A_NODE_ATTRS_DEVICE_NAME,
> + DRM_RAS_A_NODE_ATTRS_NODE_NAME,
> + DRM_RAS_A_NODE_ATTRS_NODE_TYPE,
> +
> + __DRM_RAS_A_NODE_ATTRS_MAX,
> + DRM_RAS_A_NODE_ATTRS_MAX = (__DRM_RAS_A_NODE_ATTRS_MAX - 1)
> +};
> +
> +enum {
> + DRM_RAS_A_ERROR_COUNTER_ATTRS_NODE_ID = 1,
> + DRM_RAS_A_ERROR_COUNTER_ATTRS_ERROR_ID,
> + DRM_RAS_A_ERROR_COUNTER_ATTRS_ERROR_NAME,
> + DRM_RAS_A_ERROR_COUNTER_ATTRS_ERROR_VALUE,
> +
> + __DRM_RAS_A_ERROR_COUNTER_ATTRS_MAX,
> + DRM_RAS_A_ERROR_COUNTER_ATTRS_MAX = (__DRM_RAS_A_ERROR_COUNTER_ATTRS_MAX - 1)
> +};
> +
> +enum {
> + DRM_RAS_CMD_LIST_NODES = 1,
> + DRM_RAS_CMD_GET_ERROR_COUNTERS,
> + DRM_RAS_CMD_QUERY_ERROR_COUNTER,
> +
> + __DRM_RAS_CMD_MAX,
> + DRM_RAS_CMD_MAX = (__DRM_RAS_CMD_MAX - 1)
> +};
> +
> +#endif /* _UAPI_LINUX_DRM_RAS_H */
> --
> 2.47.1
>
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