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Diffstat (limited to 'Documentation/arch/riscv/hwprobe.rst')
| -rw-r--r-- | Documentation/arch/riscv/hwprobe.rst | 122 |
1 files changed, 115 insertions, 7 deletions
diff --git a/Documentation/arch/riscv/hwprobe.rst b/Documentation/arch/riscv/hwprobe.rst index 7b2384de471f..b2bcc9eed9aa 100644 --- a/Documentation/arch/riscv/hwprobe.rst +++ b/Documentation/arch/riscv/hwprobe.rst @@ -12,7 +12,7 @@ is defined in <asm/hwprobe.h>:: }; long sys_riscv_hwprobe(struct riscv_hwprobe *pairs, size_t pair_count, - size_t cpu_count, cpu_set_t *cpus, + size_t cpusetsize, cpu_set_t *cpus, unsigned int flags); The arguments are split into three groups: an array of key-value pairs, a CPU @@ -20,12 +20,26 @@ set, and some flags. The key-value pairs are supplied with a count. Userspace must prepopulate the key field for each element, and the kernel will fill in the value if the key is recognized. If a key is unknown to the kernel, its key field will be cleared to -1, and its value set to 0. The CPU set is defined by -CPU_SET(3). For value-like keys (eg. vendor/arch/impl), the returned value will -be only be valid if all CPUs in the given set have the same value. Otherwise -1 -will be returned. For boolean-like keys, the value returned will be a logical -AND of the values for the specified CPUs. Usermode can supply NULL for cpus and -0 for cpu_count as a shortcut for all online CPUs. There are currently no flags, -this value must be zero for future compatibility. +CPU_SET(3) with size ``cpusetsize`` bytes. For value-like keys (eg. vendor, +arch, impl), the returned value will only be valid if all CPUs in the given set +have the same value. Otherwise -1 will be returned. For boolean-like keys, the +value returned will be a logical AND of the values for the specified CPUs. +Usermode can supply NULL for ``cpus`` and 0 for ``cpusetsize`` as a shortcut for +all online CPUs. The currently supported flags are: + +* :c:macro:`RISCV_HWPROBE_WHICH_CPUS`: This flag basically reverses the behavior + of sys_riscv_hwprobe(). Instead of populating the values of keys for a given + set of CPUs, the values of each key are given and the set of CPUs is reduced + by sys_riscv_hwprobe() to only those which match each of the key-value pairs. + How matching is done depends on the key type. For value-like keys, matching + means to be the exact same as the value. For boolean-like keys, matching + means the result of a logical AND of the pair's value with the CPU's value is + exactly the same as the pair's value. Additionally, when ``cpus`` is an empty + set, then it is initialized to all online CPUs which fit within it, i.e. the + CPU set returned is the reduction of all the online CPUs which can be + represented with a CPU set of size ``cpusetsize``. + +All other flags are reserved for future compatibility and must be zero. On success 0 is returned, on failure a negative error code is returned. @@ -80,6 +94,100 @@ The following keys are defined: * :c:macro:`RISCV_HWPROBE_EXT_ZICBOZ`: The Zicboz extension is supported, as ratified in commit 3dd606f ("Create cmobase-v1.0.pdf") of riscv-CMOs. + * :c:macro:`RISCV_HWPROBE_EXT_ZBC` The Zbc extension is supported, as defined + in version 1.0 of the Bit-Manipulation ISA extensions. + + * :c:macro:`RISCV_HWPROBE_EXT_ZBKB` The Zbkb extension is supported, as + defined in version 1.0 of the Scalar Crypto ISA extensions. + + * :c:macro:`RISCV_HWPROBE_EXT_ZBKC` The Zbkc extension is supported, as + defined in version 1.0 of the Scalar Crypto ISA extensions. + + * :c:macro:`RISCV_HWPROBE_EXT_ZBKX` The Zbkx extension is supported, as + defined in version 1.0 of the Scalar Crypto ISA extensions. + + * :c:macro:`RISCV_HWPROBE_EXT_ZKND` The Zknd extension is supported, as + defined in version 1.0 of the Scalar Crypto ISA extensions. + + * :c:macro:`RISCV_HWPROBE_EXT_ZKNE` The Zkne extension is supported, as + defined in version 1.0 of the Scalar Crypto ISA extensions. + + * :c:macro:`RISCV_HWPROBE_EXT_ZKNH` The Zknh extension is supported, as + defined in version 1.0 of the Scalar Crypto ISA extensions. + + * :c:macro:`RISCV_HWPROBE_EXT_ZKSED` The Zksed extension is supported, as + defined in version 1.0 of the Scalar Crypto ISA extensions. + + * :c:macro:`RISCV_HWPROBE_EXT_ZKSH` The Zksh extension is supported, as + defined in version 1.0 of the Scalar Crypto ISA extensions. + + * :c:macro:`RISCV_HWPROBE_EXT_ZKT` The Zkt extension is supported, as defined + in version 1.0 of the Scalar Crypto ISA extensions. + + * :c:macro:`RISCV_HWPROBE_EXT_ZVBB`: The Zvbb extension is supported as + defined in version 1.0 of the RISC-V Cryptography Extensions Volume II. + + * :c:macro:`RISCV_HWPROBE_EXT_ZVBC`: The Zvbc extension is supported as + defined in version 1.0 of the RISC-V Cryptography Extensions Volume II. + + * :c:macro:`RISCV_HWPROBE_EXT_ZVKB`: The Zvkb extension is supported as + defined in version 1.0 of the RISC-V Cryptography Extensions Volume II. + + * :c:macro:`RISCV_HWPROBE_EXT_ZVKG`: The Zvkg extension is supported as + defined in version 1.0 of the RISC-V Cryptography Extensions Volume II. + + * :c:macro:`RISCV_HWPROBE_EXT_ZVKNED`: The Zvkned extension is supported as + defined in version 1.0 of the RISC-V Cryptography Extensions Volume II. + + * :c:macro:`RISCV_HWPROBE_EXT_ZVKNHA`: The Zvknha extension is supported as + defined in version 1.0 of the RISC-V Cryptography Extensions Volume II. + + * :c:macro:`RISCV_HWPROBE_EXT_ZVKNHB`: The Zvknhb extension is supported as + defined in version 1.0 of the RISC-V Cryptography Extensions Volume II. + + * :c:macro:`RISCV_HWPROBE_EXT_ZVKSED`: The Zvksed extension is supported as + defined in version 1.0 of the RISC-V Cryptography Extensions Volume II. + + * :c:macro:`RISCV_HWPROBE_EXT_ZVKSH`: The Zvksh extension is supported as + defined in version 1.0 of the RISC-V Cryptography Extensions Volume II. + + * :c:macro:`RISCV_HWPROBE_EXT_ZVKT`: The Zvkt extension is supported as + defined in version 1.0 of the RISC-V Cryptography Extensions Volume II. + + * :c:macro:`RISCV_HWPROBE_EXT_ZFH`: The Zfh extension version 1.0 is supported + as defined in the RISC-V ISA manual. + + * :c:macro:`RISCV_HWPROBE_EXT_ZFHMIN`: The Zfhmin extension version 1.0 is + supported as defined in the RISC-V ISA manual. + + * :c:macro:`RISCV_HWPROBE_EXT_ZIHINTNTL`: The Zihintntl extension version 1.0 + is supported as defined in the RISC-V ISA manual. + + * :c:macro:`RISCV_HWPROBE_EXT_ZVFH`: The Zvfh extension is supported as + defined in the RISC-V Vector manual starting from commit e2ccd0548d6c + ("Remove draft warnings from Zvfh[min]"). + + * :c:macro:`RISCV_HWPROBE_EXT_ZVFHMIN`: The Zvfhmin extension is supported as + defined in the RISC-V Vector manual starting from commit e2ccd0548d6c + ("Remove draft warnings from Zvfh[min]"). + + * :c:macro:`RISCV_HWPROBE_EXT_ZFA`: The Zfa extension is supported as + defined in the RISC-V ISA manual starting from commit 056b6ff467c7 + ("Zfa is ratified"). + + * :c:macro:`RISCV_HWPROBE_EXT_ZTSO`: The Ztso extension is supported as + defined in the RISC-V ISA manual starting from commit 5618fb5a216b + ("Ztso is now ratified.") + + * :c:macro:`RISCV_HWPROBE_EXT_ZACAS`: The Zacas extension is supported as + defined in the Atomic Compare-and-Swap (CAS) instructions manual starting + from commit 5059e0ca641c ("update to ratified"). + + * :c:macro:`RISCV_HWPROBE_EXT_ZICOND`: The Zicond extension is supported as + defined in the RISC-V Integer Conditional (Zicond) operations extension + manual starting from commit 95cf1f9 ("Add changes requested by Ved + during signoff") + * :c:macro:`RISCV_HWPROBE_KEY_CPUPERF_0`: A bitmask that contains performance information about the selected set of processors. |