diff options
Diffstat (limited to 'drivers/gpu/drm/drm_ras.c')
| -rw-r--r-- | drivers/gpu/drm/drm_ras.c | 395 |
1 files changed, 395 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_ras.c b/drivers/gpu/drm/drm_ras.c new file mode 100644 index 000000000000..d6eab29a1394 --- /dev/null +++ b/drivers/gpu/drm/drm_ras.c @@ -0,0 +1,395 @@ +// SPDX-License-Identifier: MIT +/* + * Copyright © 2026 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> + +#include "drm_ras_nl.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 the below 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_COUNTER: Get error counters of a given node. + * Userspace must provide Node ID, Error ID (Optional for specific counter). + * Returns all counters of a node if only Node ID is provided or specific + * error counters. + * + * 3. CLEAR_ERROR_COUNTER: Clear error counter of a given node. + * Userspace must provide Node ID, Error ID. + * Clears specific error counter of a node if supported. + * + * 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 + * first 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_counter_dumpit(): Implements the GET_ERROR_COUNTER dumpit + * operation, fetching all counters from a specific node. + * - drm_ras_nl_get_error_counter_doit(): Implements the GET_ERROR_COUNTER doit + * operation, fetching a counter value from a specific node. + * - drm_ras_nl_clear_error_counter_doit(): Implements the CLEAR_ERROR_COUNTER doit + * operation, clearing 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; + + 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_counter_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_counter_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 || GENL_REQ_ATTR_CHECK(info, 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_get_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_get_error_counter_doit(struct sk_buff *skb, + struct genl_info *info) +{ + u32 node_id, error_id; + + if (!info->attrs || + GENL_REQ_ATTR_CHECK(info, DRM_RAS_A_ERROR_COUNTER_ATTRS_NODE_ID) || + GENL_REQ_ATTR_CHECK(info, 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_nl_clear_error_counter_doit() - Clear an error counter of a 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 + * clears the current value. + * + * Return: 0 on success, or negative errno on failure. + */ +int drm_ras_nl_clear_error_counter_doit(struct sk_buff *skb, + struct genl_info *info) +{ + struct drm_ras_node *node; + u32 node_id, error_id; + + if (!info->attrs || + GENL_REQ_ATTR_CHECK(info, DRM_RAS_A_ERROR_COUNTER_ATTRS_NODE_ID) || + GENL_REQ_ATTR_CHECK(info, 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]); + + node = xa_load(&drm_ras_xa, node_id); + if (!node || !node->clear_error_counter) + return -ENOENT; + + if (error_id < node->error_counter_range.first || + error_id > node->error_counter_range.last) + return -EINVAL; + + return node->clear_error_counter(node, 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 Endpoints are supported */ + if (node->type != DRM_RAS_NODE_TYPE_ERROR_COUNTER) + return -EINVAL; + + /* Mandatory 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); |