diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/arch/arm64/elf_hwcaps.rst | 6 | ||||
| -rw-r--r-- | Documentation/arch/riscv/uabi.rst | 20 |
2 files changed, 23 insertions, 3 deletions
diff --git a/Documentation/arch/arm64/elf_hwcaps.rst b/Documentation/arch/arm64/elf_hwcaps.rst index 4b8399ac592b..ced7b335e2e0 100644 --- a/Documentation/arch/arm64/elf_hwcaps.rst +++ b/Documentation/arch/arm64/elf_hwcaps.rst @@ -174,7 +174,7 @@ HWCAP2_DCPODP Functionality implied by ID_AA64ISAR1_EL1.DPB == 0b0010. HWCAP2_SVE2 - Functionality implied by ID_AA64ZFR0_EL1.SVEVer == 0b0001. + Functionality implied by ID_AA64ZFR0_EL1.SVEver == 0b0001. HWCAP2_SVEAES Functionality implied by ID_AA64ZFR0_EL1.AES == 0b0001. @@ -222,7 +222,7 @@ HWCAP2_RNG Functionality implied by ID_AA64ISAR0_EL1.RNDR == 0b0001. HWCAP2_BTI - Functionality implied by ID_AA64PFR0_EL1.BT == 0b0001. + Functionality implied by ID_AA64PFR1_EL1.BT == 0b0001. HWCAP2_MTE Functionality implied by ID_AA64PFR1_EL1.MTE == 0b0010, as described @@ -232,7 +232,7 @@ HWCAP2_ECV Functionality implied by ID_AA64MMFR0_EL1.ECV == 0b0001. HWCAP2_AFP - Functionality implied by ID_AA64MFR1_EL1.AFP == 0b0001. + Functionality implied by ID_AA64MMFR1_EL1.AFP == 0b0001. HWCAP2_RPRES Functionality implied by ID_AA64ISAR2_EL1.RPRES == 0b0001. diff --git a/Documentation/arch/riscv/uabi.rst b/Documentation/arch/riscv/uabi.rst index 8960fac42c40..54d199dce78b 100644 --- a/Documentation/arch/riscv/uabi.rst +++ b/Documentation/arch/riscv/uabi.rst @@ -42,6 +42,26 @@ An example string following the order is:: rv64imadc_zifoo_zigoo_zafoo_sbar_scar_zxmbaz_xqux_xrux +"isa" and "hart isa" lines in /proc/cpuinfo +------------------------------------------- + +The "isa" line in /proc/cpuinfo describes the lowest common denominator of +RISC-V ISA extensions recognized by the kernel and implemented on all harts. The +"hart isa" line, in contrast, describes the set of extensions recognized by the +kernel on the particular hart being described, even if those extensions may not +be present on all harts in the system. + +In both lines, the presence of an extension guarantees only that the hardware +has the described capability. Additional kernel support or policy changes may be +required before an extension's capability is fully usable by userspace programs. +Similarly, for S-mode extensions, presence in one of these lines does not +guarantee that the kernel is taking advantage of the extension, or that the +feature will be visible in guest VMs managed by this kernel. + +Inversely, the absence of an extension in these lines does not necessarily mean +the hardware does not support that feature. The running kernel may not recognize +the extension, or may have deliberately removed it from the listing. + Misaligned accesses ------------------- |