Lines Matching +full:acpi +full:- +full:based
1 .. SPDX-License-Identifier: GPL-2.0 OR GFDL-1.2-no-invariants-or-later
7 Copyright (c) 2024-2025 HiSilicon Limited.
11 Invariant Sections, Front-Cover Texts nor Back-Cover Texts.
14 - Written for: 6.15
17 ------------
24 Memory scrubbing is a feature where an ECC (Error-Correcting Code) engine
49 2. On-demand scrubbing for a specific address range or region of memory.
52 identified, such as CXL memory device patrol scrub, CXL DDR5 ECS, ACPI
53 RAS2 memory scrubbing, and ACPI NVDIMM ARS (Address Range Scrub).
65 -----------------------------------------
69 ACPI RAS2 memory scrubbing features, ACPI NVDIMM ARS (Address Range Scrub),
70 and software-based memory scrubbers.
73 control over patrol (background) scrubbing (e.g., ACPI RAS2, CXL) and/or
74 on-demand scrubbing (e.g., ACPI RAS2, ACPI ARS). However, the scrub control
79 2. User-space scrub controls allow users to disable scrubbing if necessary,
81 rate for performance-aware operations where background activities need to
84 3. User-space tools enable on-demand scrubbing for specific address ranges,
87 4. User-space tools can also control memory DIMM scrubbing at a configurable
97 be a system-wide BIOS or similar control to manage scrub settings for a CXL
105 ------------------
123 with performance-aware operations which require the background operations to
130 - a feature defined in the JEDEC DDR5 SDRAM Specification (JESD79-5) and
131 allowing DRAM to internally read, correct single-bit errors, and write back
139 ACPI RAS2 Hardware-based Memory Scrubbing
142 ACPI spec 6.5 [2]_ section 5.2.21 ACPI RAS2 describes an ACPI RAS2 table
148 are specific to memory. RAS2 PCC sub-spaces for memory-specific RAS features
151 The platform can use the hardware-based memory scrubbing feature to expose
152 controls and capabilities associated with hardware-based memory scrub
159 as well as on-demand scrubbing for a specific region of memory.
161 ACPI Address Range Scrubbing (ARS)
164 ACPI spec 6.5 [2]_ section 9.19.7.2 describes Address Range Scrubbing (ARS).
173 supports the ACPI NVDIMM Root Device Unconsumed Error Notification.
190 .. [1] https://computeexpresslink.org/cxl-specification/
192 .. [2] https://uefi.org/specs/ACPI/6.5/
197 +--------------+-----------+-----------+-----------+-----------+
198 | | ACPI | CXL patrol| CXL ECS | ARS |
200 +--------------+-----------+-----------+-----------+-----------+
202 | On-demand | Supported | No | No | Supported |
205 +--------------+-----------+-----------+-----------+-----------+
210 +--------------+-----------+-----------+-----------+-----------+
215 +--------------+-----------+-----------+-----------+-----------+
220 +--------------+-----------+-----------+-----------+-----------+
225 +--------------+-----------+-----------+-----------+-----------+
230 +--------------+-----------+-----------+-----------+-----------+
235 +--------------+-----------+-----------+-----------+-----------+
237 | Scrub | on-demand | No | No | Supported |
240 +--------------+-----------+-----------+-----------+-----------+
241 | UC error | |CXL general|CXL general| ACPI UCE |
245 +--------------+-----------+-----------+-----------+-----------+
250 +--------------+-----------+-----------+-----------+-----------+
253 ---------------
258 /sys/bus/edac/devices/<dev-name>/scrubX/
261 -----
264 `Documentation/ABI/testing/sysfs-edac-scrub`
266 `Documentation/ABI/testing/sysfs-edac-ecs`
269 --------
277 - Scrubbing is needed at device granularity because a device is showing
280 - Scrubbing may apply to memory that isn't online at all yet. Likely this
283 - Scrubbing at a higher rate because the monitor software has determined that
287 1.1. Device based scrubbing
290 via CXL devices. Device-based scrubbing is used for the first use case
294 "see Section 1.2 Region based scrubbing".
297 `Documentation/ABI/testing/sysfs-edac-scrub`
299 1.2. Region based scrubbing
311 Region-based scrubbing is used for the third use case described in
327 `Documentation/ABI/testing/sysfs-edac-scrub`
332 checking and correction (ECC) and count single-bit errors. The associated
342 `Documentation/ABI/testing/sysfs-edac-ecs`