diff options
| author |   Palmer Dabbelt <palmer@rivosinc.com> | 2023-06-19 14:34:40 -0700 |
|---|---|---|
| committer | Palmer Dabbelt <palmer@rivosinc.com> | 2023-06-19 14:34:40 -0700 |
| commit | 16252e018a30486eedcfec81fc313445cac25bea (patch) | |
| tree | 5cddc30da8c3b5c7c71bceb8f90c219d018c5a85 /arch/riscv/kernel/sys_riscv.c | |
| parent | dt-bindings: riscv: cpus: drop unneeded quotes (diff) | |
| parent | RISC-V: hwprobe: Expose Zba, Zbb, and Zbs (diff) | |
| download | wireguard-linux-16252e018a30486eedcfec81fc313445cac25bea.tar.xz wireguard-linux-16252e018a30486eedcfec81fc313445cac25bea.zip | |
Merge patch series "RISC-V: Export Zba, Zbb to usermode via hwprobe"
Evan Green <evan@rivosinc.com> says:
This change detects the presence of Zba, Zbb, and Zbs extensions and exports
them per-hart to userspace via the hwprobe mechanism. Glibc can then use
these in setting up hwcaps-based library search paths.
There's a little bit of extra housekeeping here: the first change adds
Zba and Zbs to the set of extensions the kernel recognizes, and the second
change starts tracking ISA features per-hart (in addition to the ANDed
mask of features across all harts which the kernel uses to make
decisions). Now that we track the ISA information per-hart, we could
even fix up /proc/cpuinfo to accurately report extension per-hart,
though I've left that out of this series for now.
* b4-shazam-merge:
RISC-V: hwprobe: Expose Zba, Zbb, and Zbs
RISC-V: Track ISA extensions per hart
RISC-V: Add Zba, Zbs extension probing
Link: https://lore.kernel.org/r/20230509182504.2997252-1-evan@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Diffstat (limited to 'arch/riscv/kernel/sys_riscv.c')
| -rw-r--r-- | arch/riscv/kernel/sys_riscv.c | 54 |
1 files changed, 44 insertions, 10 deletions
diff --git a/arch/riscv/kernel/sys_riscv.c b/arch/riscv/kernel/sys_riscv.c index 88357a848797..26ef5526bfb4 100644 --- a/arch/riscv/kernel/sys_riscv.c +++ b/arch/riscv/kernel/sys_riscv.c @@ -122,6 +122,49 @@ static void hwprobe_arch_id(struct riscv_hwprobe *pair, pair->value = id; } +static void hwprobe_isa_ext0(struct riscv_hwprobe *pair, + const struct cpumask *cpus) +{ + int cpu; + u64 missing = 0; + + pair->value = 0; + if (has_fpu()) + pair->value |= RISCV_HWPROBE_IMA_FD; + + if (riscv_isa_extension_available(NULL, c)) + pair->value |= RISCV_HWPROBE_IMA_C; + + if (has_vector()) + pair->value |= RISCV_HWPROBE_IMA_V; + + /* + * Loop through and record extensions that 1) anyone has, and 2) anyone + * doesn't have. + */ + for_each_cpu(cpu, cpus) { + struct riscv_isainfo *isainfo = &hart_isa[cpu]; + + if (riscv_isa_extension_available(isainfo->isa, ZBA)) + pair->value |= RISCV_HWPROBE_EXT_ZBA; + else + missing |= RISCV_HWPROBE_EXT_ZBA; + + if (riscv_isa_extension_available(isainfo->isa, ZBB)) + pair->value |= RISCV_HWPROBE_EXT_ZBB; + else + missing |= RISCV_HWPROBE_EXT_ZBB; + + if (riscv_isa_extension_available(isainfo->isa, ZBS)) + pair->value |= RISCV_HWPROBE_EXT_ZBS; + else + missing |= RISCV_HWPROBE_EXT_ZBS; + } + + /* Now turn off reporting features if any CPU is missing it. */ + pair->value &= ~missing; +} + static u64 hwprobe_misaligned(const struct cpumask *cpus) { int cpu; @@ -165,16 +208,7 @@ static void hwprobe_one_pair(struct riscv_hwprobe *pair, break; case RISCV_HWPROBE_KEY_IMA_EXT_0: - pair->value = 0; - if (has_fpu()) - pair->value |= RISCV_HWPROBE_IMA_FD; - - if (riscv_isa_extension_available(NULL, c)) - pair->value |= RISCV_HWPROBE_IMA_C; - - if (has_vector()) - pair->value |= RISCV_HWPROBE_IMA_V; - + hwprobe_isa_ext0(pair, cpus); break; case RISCV_HWPROBE_KEY_CPUPERF_0: |