src/riscv/linux/riscv-isa.c

#include <string.h>
#include <sys/auxv.h>

#include <riscv/linux/api.h>

/**
 * arch/riscv/include/uapi/asm/hwcap.h
 *
 * This must be kept in sync with the upstream kernel header.
 */
#define COMPAT_HWCAP_ISA_I (1 << ('I' - 'A'))
#define COMPAT_HWCAP_ISA_M (1 << ('M' - 'A'))
#define COMPAT_HWCAP_ISA_A (1 << ('A' - 'A'))
#define COMPAT_HWCAP_ISA_F (1 << ('F' - 'A'))
#define COMPAT_HWCAP_ISA_D (1 << ('D' - 'A'))
#define COMPAT_HWCAP_ISA_C (1 << ('C' - 'A'))
#define COMPAT_HWCAP_ISA_V (1 << ('V' - 'A'))

void cpuinfo_riscv_linux_decode_isa_from_hwcap(struct cpuinfo_riscv_isa isa[restrict static 1]) {
	const unsigned long hwcap = getauxval(AT_HWCAP);

	if (hwcap & COMPAT_HWCAP_ISA_I) {
		isa->i = true;
	}
	if (hwcap & COMPAT_HWCAP_ISA_M) {
		isa->m = true;
	}
	if (hwcap & COMPAT_HWCAP_ISA_A) {
		isa->a = true;
	}
	if (hwcap & COMPAT_HWCAP_ISA_F) {
		isa->f = true;
	}
	if (hwcap & COMPAT_HWCAP_ISA_D) {
		isa->d = true;
	}
	if (hwcap & COMPAT_HWCAP_ISA_C) {
		isa->c = true;
	}
	if (hwcap & COMPAT_HWCAP_ISA_V) {
		isa->v = true;
	}
}