On Fri, Dec 05, 2025 at 02:09:33PM +0530, Riana Tauro wrote: > From: Rodrigo Vivi <[email protected]> > > 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 <[email protected]> > Cc: Lukas Wunner <[email protected]> > Cc: Lijo Lazar <[email protected]> > Cc: Hawking Zhang <[email protected]> > Cc: Jakub Kicinski <[email protected]> > Cc: David S. Miller <[email protected]> > Cc: Paolo Abeni <[email protected]> > Cc: Eric Dumazet <[email protected]> > Cc: [email protected] > Co-developed-by: Aravind Iddamsetty <[email protected]> > Signed-off-by: Aravind Iddamsetty <[email protected]> > Signed-off-by: Rodrigo Vivi <[email protected]> > Signed-off-by: Riana Tauro <[email protected]> > --- > 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 <[email protected]> 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 >
