diff options
| author | Richard Henderson <richard.henderson@linaro.org> | 2024-06-27 17:36:43 +0000 |
|---|---|---|
| committer | Richard Henderson <richard.henderson@linaro.org> | 2024-07-03 10:24:12 -0700 |
| commit | e57173085aab2dae3fb8b777ea9a4a252feb78a6 (patch) | |
| tree | c86b4adae8ab2fa4595146025cc872fbd1aaf126 /util | |
| parent | adc028428a6da5ea8d6a688085966a33be4c97c7 (diff) | |
util/cpuinfo-riscv: Use linux __riscv_hwprobe syscall
With recent linux kernels, there is a syscall to probe for various
ISA extensions. These bits were phased in over several kernel
releases, so we still require checks for symbol availability.
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Diffstat (limited to 'util')
| -rw-r--r-- | util/cpuinfo-riscv.c | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/util/cpuinfo-riscv.c b/util/cpuinfo-riscv.c index 7dcfbee2ab..497ce12680 100644 --- a/util/cpuinfo-riscv.c +++ b/util/cpuinfo-riscv.c @@ -6,6 +6,11 @@ #include "qemu/osdep.h" #include "host/cpuinfo.h" +#ifdef CONFIG_ASM_HWPROBE_H +#include <asm/hwprobe.h> +#include <sys/syscall.h> +#endif + unsigned cpuinfo; static volatile sig_atomic_t got_sigill; @@ -47,6 +52,27 @@ unsigned __attribute__((constructor)) cpuinfo_init(void) #endif left &= ~info; +#ifdef CONFIG_ASM_HWPROBE_H + if (left) { + /* + * TODO: glibc 2.40 will introduce <sys/hwprobe.h>, which + * provides __riscv_hwprobe and __riscv_hwprobe_one, + * which is a slightly cleaner interface. + */ + struct riscv_hwprobe pair = { .key = RISCV_HWPROBE_KEY_IMA_EXT_0 }; + if (syscall(__NR_riscv_hwprobe, &pair, 1, 0, NULL, 0) == 0 + && pair.key >= 0) { + info |= pair.value & RISCV_HWPROBE_EXT_ZBA ? CPUINFO_ZBA : 0; + info |= pair.value & RISCV_HWPROBE_EXT_ZBB ? CPUINFO_ZBB : 0; + left &= ~(CPUINFO_ZBA | CPUINFO_ZBB); +#ifdef RISCV_HWPROBE_EXT_ZICOND + info |= pair.value & RISCV_HWPROBE_EXT_ZICOND ? CPUINFO_ZICOND : 0; + left &= ~CPUINFO_ZICOND; +#endif + } + } +#endif /* CONFIG_ASM_HWPROBE_H */ + if (left) { struct sigaction sa_old, sa_new; |