[PATCH 2/3] arm64: Document missing bitfields in cpu-feature-registers.rst
Mark Brown
broonie at kernel.org
Fri May 22 10:58:38 PDT 2026
We have been rather lax in updating the list of visible bitfields in the
ID registers in cpu-feature-registers.rst, it is currently missing several
of the registers and quite a few bitfields in existing registers. Bring it
into sync with current -next.
Signed-off-by: Mark Brown <broonie at kernel.org>
---
Documentation/arch/arm64/cpu-feature-registers.rst | 146 +++++++++++++++++++++
1 file changed, 146 insertions(+)
diff --git a/Documentation/arch/arm64/cpu-feature-registers.rst b/Documentation/arch/arm64/cpu-feature-registers.rst
index c6e5bc053c09..02815db0c780 100644
--- a/Documentation/arch/arm64/cpu-feature-registers.rst
+++ b/Documentation/arch/arm64/cpu-feature-registers.rst
@@ -113,6 +113,30 @@ infrastructure:
4. List of registers with visible features
-------------------------------------------
+ ID_AA6FPFR0_EL1 - Floating Point feature ID register 0
+
+ +------------------------------+---------+---------+
+ | Name | bits | visible |
+ +------------------------------+---------+---------+
+ | F8CVT | [31] | y |
+ +------------------------------+---------+---------+
+ | F8FMA | [30] | y |
+ +------------------------------+---------+---------+
+ | F8DP4 | [29] | y |
+ +------------------------------+---------+---------+
+ | F8DP2 | [28] | y |
+ +------------------------------+---------+---------+
+ | F8MM8 | [27] | y |
+ +------------------------------+---------+---------+
+ | F8MM4 | [26] | y |
+ +------------------------------+---------+---------+
+ | F16MM2 | [15] | y |
+ +------------------------------+---------+---------+
+ | F8E4M3 | [1] | y |
+ +------------------------------+---------+---------+
+ | F8E5M2 | [0] | y |
+ +------------------------------+---------+---------+
+
ID_AA64ISAR0_EL1 - Instruction Set Attribute Register 0
+------------------------------+---------+---------+
@@ -178,6 +202,8 @@ infrastructure:
+------------------------------+---------+---------+
| Name | bits | visible |
+------------------------------+---------+---------+
+ | GCS | [47-44] | y |
+ +------------------------------+---------+---------+
| SME | [27-24] | y |
+------------------------------+---------+---------+
| MTE | [11-8] | y |
@@ -187,6 +213,17 @@ infrastructure:
| BT | [3-0] | y |
+------------------------------+---------+---------+
+ ID_AA64PFR2_EL1 - Processor Feature Register 2
+
+ +------------------------------+---------+---------+
+ | Name | bits | visible |
+ +------------------------------+---------+---------+
+ | FPMR | [35-32] | y |
+ +------------------------------+---------+---------+
+ | MTEFAR | [11-8] | y |
+ +------------------------------+---------+---------+
+ | MTESTOREONLY | [7-4] | y |
+ +------------------------------+---------+---------+
MIDR_EL1 - Main ID Register
@@ -213,6 +250,8 @@ infrastructure:
+------------------------------+---------+---------+
| Name | bits | visible |
+------------------------------+---------+---------+
+ | LS64 | [63-60] | y |
+ +------------------------------+---------+---------+
| I8MM | [55-52] | y |
+------------------------------+---------+---------+
| DGH | [51-48] | y |
@@ -256,6 +295,68 @@ infrastructure:
| AT | [35-32] | y |
+------------------------------+---------+---------+
+ ID_AA64MMFR3_EL1 - Memory model feature register 3
+
+ +------------------------------+---------+---------+
+ | Name | bits | visible |
+ +------------------------------+---------+---------+
+ | S1POE | [19-16] | y |
+ +------------------------------+---------+---------+
+
+ ID_AA6SMFR0_EL1 - SME feature ID register 0
+
+ +------------------------------+---------+---------+
+ | Name | bits | visible |
+ +------------------------------+---------+---------+
+ | FA64 | [63] | y |
+ +------------------------------+---------+---------+
+ | LUT6 | [61] | y |
+ +------------------------------+---------+---------+
+ | LUTv2 | [60] | y |
+ +------------------------------+---------+---------+
+ | SMEver | [59-56] | y |
+ +------------------------------+---------+---------+
+ | I16I64 | [55-52] | y |
+ +------------------------------+---------+---------+
+ | F64F64 | [48] | y |
+ +------------------------------+---------+---------+
+ | I16I32 | [47-44] | y |
+ +------------------------------+---------+---------+
+ | B16B16 | [43] | y |
+ +------------------------------+---------+---------+
+ | F16F16 | [42] | y |
+ +------------------------------+---------+---------+
+ | F8F16 | [41] | y |
+ +------------------------------+---------+---------+
+ | F8F32 | [40] | y |
+ +------------------------------+---------+---------+
+ | I8I32 | [39-36] | y |
+ +------------------------------+---------+---------+
+ | F16F32 | [35] | y |
+ +------------------------------+---------+---------+
+ | B16F32 | [34] | y |
+ +------------------------------+---------+---------+
+ | BI32I32 | [33] | y |
+ +------------------------------+---------+---------+
+ | F32F32 | [32] | y |
+ +------------------------------+---------+---------+
+ | SF8FMA | [30] | y |
+ +------------------------------+---------+---------+
+ | SF8DP4 | [29] | y |
+ +------------------------------+---------+---------+
+ | SF8DP2 | [28] | y |
+ +------------------------------+---------+---------+
+ | SBitPerm | [25] | y |
+ +------------------------------+---------+---------+
+ | AES | [24] | y |
+ +------------------------------+---------+---------+
+ | SFEXPA | [23] | y |
+ +------------------------------+---------+---------+
+ | STMOP | [16] | y |
+ +------------------------------+---------+---------+
+ | SMOP4 | [0] | y |
+ +------------------------------+---------+---------+
+
ID_AA64ZFR0_EL1 - SVE feature ID register 0
+------------------------------+---------+---------+
@@ -265,6 +366,8 @@ infrastructure:
+------------------------------+---------+---------+
| F32MM | [55-52] | y |
+------------------------------+---------+---------+
+ | F16MM | [51-48] | y |
+ +------------------------------+---------+---------+
| I8MM | [47-44] | y |
+------------------------------+---------+---------+
| SM4 | [43-40] | y |
@@ -277,6 +380,8 @@ infrastructure:
+------------------------------+---------+---------+
| BitPerm | [19-16] | y |
+------------------------------+---------+---------+
+ | EltPerm | [15-12] | y |
+ +------------------------------+---------+---------+
| AES | [7-4] | y |
+------------------------------+---------+---------+
| SVEVer | [3-0] | y |
@@ -295,6 +400,8 @@ infrastructure:
+------------------------------+---------+---------+
| Name | bits | visible |
+------------------------------+---------+---------+
+ | LUT | [59-56] | y |
+ +------------------------------+---------+---------+
| CSSC | [55-52] | y |
+------------------------------+---------+---------+
| RPRFM | [51-48] | y |
@@ -312,6 +419,18 @@ infrastructure:
| WFXT | [3-0] | y |
+------------------------------+---------+---------+
+ ID_AA64ISAR3_EL1 - Instruction set attribute register 3
+
+ +------------------------------+---------+---------+
+ | Name | bits | visible |
+ +------------------------------+---------+---------+
+ | FPRCVT | [31-28] | y |
+ +------------------------------+---------+---------+
+ | LSFE | [19-16] | y |
+ +------------------------------+---------+---------+
+ | FAMINMAX | [7-4] | y |
+ +------------------------------+---------+---------+
+
MVFR0_EL1 - AArch32 Media and VFP Feature Register 0
+------------------------------+---------+---------+
@@ -327,6 +446,10 @@ infrastructure:
+------------------------------+---------+---------+
| SIMDFMAC | [31-28] | y |
+------------------------------+---------+---------+
+ | FPHP | [27-24] | y |
+ +------------------------------+---------+---------+
+ | SIMDHP | [23-20] | y |
+ +------------------------------+---------+---------+
| SIMDSP | [19-16] | y |
+------------------------------+---------+---------+
| SIMDInt | [15-12] | y |
@@ -348,6 +471,29 @@ infrastructure:
| AES | [7-4] | y |
+------------------------------+---------+---------+
+ ID_ISAR6_EL1 - AArch32 Instruction Set Attribute Register 6
+
+ +------------------------------+---------+---------+
+ | Name | bits | visible |
+ +------------------------------+---------+---------+
+ | I8MM | [27-24] | y |
+ +------------------------------+---------+---------+
+ | BF16 | [23-20] | y |
+ +------------------------------+---------+---------+
+ | SB | [15-12] | y |
+ +------------------------------+---------+---------+
+ | FHM | [11-8] | y |
+ +------------------------------+---------+---------+
+ | DP | [7-4] | y |
+ +------------------------------+---------+---------+
+
+ ID_PFR2_EL1 - AArch32 Processor Feature Register 2
+
+ +------------------------------+---------+---------+
+ | Name | bits | visible |
+ +------------------------------+---------+---------+
+ | SSBS | [7-4] | y |
+ +------------------------------+---------+---------+
Appendix I: Example
-------------------
--
2.47.3
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