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- .. SPDX-License-Identifier: GPL-2.0 OR GFDL-1.2-no-invariants-or-later
- =================
- EDAC/RAS features
- =================
- Copyright (c) 2024-2025 HiSilicon Limited.
- :Author: Shiju Jose <shiju.jose@huawei.com>
- :License: The GNU Free Documentation License, Version 1.2 without
- Invariant Sections, Front-Cover Texts nor Back-Cover Texts.
- (dual licensed under the GPL v2)
- - Written for: 6.15
- Introduction
- ------------
- EDAC/RAS components plugging and high-level design:
- 1. Scrub control
- 2. Error Check Scrub (ECS) control
- 3. ACPI RAS2 features
- 4. Post Package Repair (PPR) control
- 5. Memory Sparing Repair control
- High level design is illustrated in the following diagram::
- +-----------------------------------------------+
- | Userspace - Rasdaemon |
- | +-------------+ |
- | | RAS CXL mem | +---------------+ |
- | |error handler|---->| | |
- | +-------------+ | RAS dynamic | |
- | +-------------+ | scrub, memory | |
- | | RAS memory |---->| repair control| |
- | |error handler| +----|----------+ |
- | +-------------+ | |
- +--------------------------|--------------------+
- |
- |
- +-------------------------------|------------------------------+
- | Kernel EDAC extension for | controlling RAS Features |
- |+------------------------------|----------------------------+ |
- || EDAC Core Sysfs EDAC| Bus | |
- || +--------------------------|---------------------------+| |
- || |/sys/bus/edac/devices/<dev>/scrubX/ | | EDAC device || |
- || |/sys/bus/edac/devices/<dev>/ecsX/ |<->| EDAC MC || |
- || |/sys/bus/edac/devices/<dev>/repairX | | EDAC sysfs || |
- || +---------------------------|--------------------------+| |
- || EDAC|Bus | |
- || | | |
- || +----------+ Get feature | Get feature | |
- || | | desc +---------|------+ desc +----------+ | |
- || |EDAC scrub|<-----| EDAC device | | | | |
- || +----------+ | driver- RAS |----->| EDAC mem | | |
- || +----------+ | feature control| | repair | | |
- || | |<-----| | +----------+ | |
- || |EDAC ECS | +---------|------+ | |
- || +----------+ Register RAS|features | |
- || ______________________|_____________ | |
- |+---------|---------------|------------------|--------------+ |
- | +-------|----+ +-------|-------+ +----|----------+ |
- | | | | CXL mem driver| | Client driver | |
- | | ACPI RAS2 | | scrub, ECS, | | memory repair | |
- | | driver | | sparing, PPR | | features | |
- | +-----|------+ +-------|-------+ +------|--------+ |
- | | | | |
- +--------|-----------------|--------------------|--------------+
- | | |
- +--------|-----------------|--------------------|--------------+
- | +---|-----------------|--------------------|-------+ |
- | | | |
- | | Platform HW and Firmware | |
- | +--------------------------------------------------+ |
- +--------------------------------------------------------------+
- 1. EDAC Features components - Create feature-specific descriptors. For
- example: scrub, ECS, memory repair in the above diagram.
- 2. EDAC device driver for controlling RAS Features - Get feature's attribute
- descriptors from EDAC RAS feature component and registers device's RAS
- features with EDAC bus and expose the features control attributes via
- sysfs. For example, /sys/bus/edac/devices/<dev-name>/<feature>X/
- 3. RAS dynamic feature controller - Userspace sample modules in rasdaemon for
- dynamic scrub/repair control to issue scrubbing/repair when excess number
- of corrected memory errors are reported in a short span of time.
- RAS features
- ------------
- 1. Memory Scrub
- Memory scrub features are documented in `Documentation/edac/scrub.rst`.
- 2. Memory Repair
- Memory repair features are documented in `Documentation/edac/memory_repair.rst`.
|
