diff options
Diffstat (limited to 'Documentation/arm64')
| -rw-r--r-- | Documentation/arm64/cpu-feature-registers.txt | 16 | ||||
| -rw-r--r-- | Documentation/arm64/elf_hwcaps.txt | 41 | ||||
| -rw-r--r-- | Documentation/arm64/silicon-errata.txt | 1 | ||||
| -rw-r--r-- | Documentation/arm64/sve.txt | 17 |
4 files changed, 72 insertions, 3 deletions
diff --git a/Documentation/arm64/cpu-feature-registers.txt b/Documentation/arm64/cpu-feature-registers.txt index d4b4dd1fe786..684a0da39378 100644 --- a/Documentation/arm64/cpu-feature-registers.txt +++ b/Documentation/arm64/cpu-feature-registers.txt @@ -209,6 +209,22 @@ infrastructure: | AT | [35-32] | y | x--------------------------------------------------x + 6) ID_AA64ZFR0_EL1 - SVE feature ID register 0 + + x--------------------------------------------------x + | Name | bits | visible | + |--------------------------------------------------| + | SM4 | [43-40] | y | + |--------------------------------------------------| + | SHA3 | [35-32] | y | + |--------------------------------------------------| + | BitPerm | [19-16] | y | + |--------------------------------------------------| + | AES | [7-4] | y | + |--------------------------------------------------| + | SVEVer | [3-0] | y | + x--------------------------------------------------x + Appendix I: Example --------------------------- diff --git a/Documentation/arm64/elf_hwcaps.txt b/Documentation/arm64/elf_hwcaps.txt index 13d6691b37be..b73a2519ecf2 100644 --- a/Documentation/arm64/elf_hwcaps.txt +++ b/Documentation/arm64/elf_hwcaps.txt @@ -13,9 +13,9 @@ architected discovery mechanism available to userspace code at EL0. The kernel exposes the presence of these features to userspace through a set of flags called hwcaps, exposed in the auxilliary vector. -Userspace software can test for features by acquiring the AT_HWCAP entry -of the auxilliary vector, and testing whether the relevant flags are -set, e.g. +Userspace software can test for features by acquiring the AT_HWCAP or +AT_HWCAP2 entry of the auxiliary vector, and testing whether the relevant +flags are set, e.g. bool floating_point_is_present(void) { @@ -135,6 +135,10 @@ HWCAP_DCPOP Functionality implied by ID_AA64ISAR1_EL1.DPB == 0b0001. +HWCAP2_DCPODP + + Functionality implied by ID_AA64ISAR1_EL1.DPB == 0b0010. + HWCAP_SHA3 Functionality implied by ID_AA64ISAR0_EL1.SHA3 == 0b0001. @@ -159,6 +163,30 @@ HWCAP_SVE Functionality implied by ID_AA64PFR0_EL1.SVE == 0b0001. +HWCAP2_SVE2 + + Functionality implied by ID_AA64ZFR0_EL1.SVEVer == 0b0001. + +HWCAP2_SVEAES + + Functionality implied by ID_AA64ZFR0_EL1.AES == 0b0001. + +HWCAP2_SVEPMULL + + Functionality implied by ID_AA64ZFR0_EL1.AES == 0b0010. + +HWCAP2_SVEBITPERM + + Functionality implied by ID_AA64ZFR0_EL1.BitPerm == 0b0001. + +HWCAP2_SVESHA3 + + Functionality implied by ID_AA64ZFR0_EL1.SHA3 == 0b0001. + +HWCAP2_SVESM4 + + Functionality implied by ID_AA64ZFR0_EL1.SM4 == 0b0001. + HWCAP_ASIMDFHM Functionality implied by ID_AA64ISAR0_EL1.FHM == 0b0001. @@ -194,3 +222,10 @@ HWCAP_PACG Functionality implied by ID_AA64ISAR1_EL1.GPA == 0b0001 or ID_AA64ISAR1_EL1.GPI == 0b0001, as described by Documentation/arm64/pointer-authentication.txt. + + +4. Unused AT_HWCAP bits +----------------------- + +For interoperation with userspace, the kernel guarantees that bits 62 +and 63 of AT_HWCAP will always be returned as 0. diff --git a/Documentation/arm64/silicon-errata.txt b/Documentation/arm64/silicon-errata.txt index c00efb639e46..68d9b74fd751 100644 --- a/Documentation/arm64/silicon-errata.txt +++ b/Documentation/arm64/silicon-errata.txt @@ -61,6 +61,7 @@ stable kernels. | ARM | Cortex-A76 | #1188873 | ARM64_ERRATUM_1188873 | | ARM | Cortex-A76 | #1165522 | ARM64_ERRATUM_1165522 | | ARM | Cortex-A76 | #1286807 | ARM64_ERRATUM_1286807 | +| ARM | Neoverse-N1 | #1188873 | ARM64_ERRATUM_1188873 | | ARM | MMU-500 | #841119,#826419 | N/A | | | | | | | Cavium | ThunderX ITS | #22375, #24313 | CAVIUM_ERRATUM_22375 | diff --git a/Documentation/arm64/sve.txt b/Documentation/arm64/sve.txt index 7169a0ec41d8..9940e924a47e 100644 --- a/Documentation/arm64/sve.txt +++ b/Documentation/arm64/sve.txt @@ -34,6 +34,23 @@ model features for SVE is included in Appendix A. following sections: software that needs to verify that those interfaces are present must check for HWCAP_SVE instead. +* On hardware that supports the SVE2 extensions, HWCAP2_SVE2 will also + be reported in the AT_HWCAP2 aux vector entry. In addition to this, + optional extensions to SVE2 may be reported by the presence of: + + HWCAP2_SVE2 + HWCAP2_SVEAES + HWCAP2_SVEPMULL + HWCAP2_SVEBITPERM + HWCAP2_SVESHA3 + HWCAP2_SVESM4 + + This list may be extended over time as the SVE architecture evolves. + + These extensions are also reported via the CPU ID register ID_AA64ZFR0_EL1, + which userspace can read using an MRS instruction. See elf_hwcaps.txt and + cpu-feature-registers.txt for details. + * Debuggers should restrict themselves to interacting with the target via the NT_ARM_SVE regset. The recommended way of detecting support for this regset is to connect to a target process first and then attempt a |
