f-stack/dpdk/lib/eal/riscv/rte_cpuflags.c

123 lines
2.8 KiB
C

/* SPDX-License-Identifier: BSD-3-Clause
* Copyright(c) 2022 StarFive
* Copyright(c) 2022 SiFive
* Copyright(c) 2022 Semihalf
*/
#include "rte_cpuflags.h"
#include <elf.h>
#include <fcntl.h>
#include <assert.h>
#include <unistd.h>
#include <string.h>
#ifndef AT_HWCAP
#define AT_HWCAP 16
#endif
#ifndef AT_HWCAP2
#define AT_HWCAP2 26
#endif
#ifndef AT_PLATFORM
#define AT_PLATFORM 15
#endif
enum cpu_register_t {
REG_NONE = 0,
REG_HWCAP,
REG_HWCAP2,
REG_PLATFORM,
REG_MAX
};
typedef uint32_t hwcap_registers_t[REG_MAX];
/**
* Struct to hold a processor feature entry
*/
struct feature_entry {
uint32_t reg;
uint32_t bit;
#define CPU_FLAG_NAME_MAX_LEN 64
char name[CPU_FLAG_NAME_MAX_LEN];
};
#define FEAT_DEF(name, reg, bit) \
[RTE_CPUFLAG_##name] = {reg, bit, #name},
typedef Elf64_auxv_t _Elfx_auxv_t;
const struct feature_entry rte_cpu_feature_table[] = {
FEAT_DEF(RISCV_ISA_A, REG_HWCAP, 0)
FEAT_DEF(RISCV_ISA_B, REG_HWCAP, 1)
FEAT_DEF(RISCV_ISA_C, REG_HWCAP, 2)
FEAT_DEF(RISCV_ISA_D, REG_HWCAP, 3)
FEAT_DEF(RISCV_ISA_E, REG_HWCAP, 4)
FEAT_DEF(RISCV_ISA_F, REG_HWCAP, 5)
FEAT_DEF(RISCV_ISA_G, REG_HWCAP, 6)
FEAT_DEF(RISCV_ISA_H, REG_HWCAP, 7)
FEAT_DEF(RISCV_ISA_I, REG_HWCAP, 8)
FEAT_DEF(RISCV_ISA_J, REG_HWCAP, 9)
FEAT_DEF(RISCV_ISA_K, REG_HWCAP, 10)
FEAT_DEF(RISCV_ISA_L, REG_HWCAP, 11)
FEAT_DEF(RISCV_ISA_M, REG_HWCAP, 12)
FEAT_DEF(RISCV_ISA_N, REG_HWCAP, 13)
FEAT_DEF(RISCV_ISA_O, REG_HWCAP, 14)
FEAT_DEF(RISCV_ISA_P, REG_HWCAP, 15)
FEAT_DEF(RISCV_ISA_Q, REG_HWCAP, 16)
FEAT_DEF(RISCV_ISA_R, REG_HWCAP, 17)
FEAT_DEF(RISCV_ISA_S, REG_HWCAP, 18)
FEAT_DEF(RISCV_ISA_T, REG_HWCAP, 19)
FEAT_DEF(RISCV_ISA_U, REG_HWCAP, 20)
FEAT_DEF(RISCV_ISA_V, REG_HWCAP, 21)
FEAT_DEF(RISCV_ISA_W, REG_HWCAP, 22)
FEAT_DEF(RISCV_ISA_X, REG_HWCAP, 23)
FEAT_DEF(RISCV_ISA_Y, REG_HWCAP, 24)
FEAT_DEF(RISCV_ISA_Z, REG_HWCAP, 25)
};
/*
* Read AUXV software register and get cpu features for ARM
*/
static void
rte_cpu_get_features(hwcap_registers_t out)
{
out[REG_HWCAP] = rte_cpu_getauxval(AT_HWCAP);
out[REG_HWCAP2] = rte_cpu_getauxval(AT_HWCAP2);
}
/*
* Checks if a particular flag is available on current machine.
*/
int
rte_cpu_get_flag_enabled(enum rte_cpu_flag_t feature)
{
const struct feature_entry *feat;
hwcap_registers_t regs = {0};
if (feature >= RTE_CPUFLAG_NUMFLAGS)
return -ENOENT;
feat = &rte_cpu_feature_table[feature];
if (feat->reg == REG_NONE)
return -EFAULT;
rte_cpu_get_features(regs);
return (regs[feat->reg] >> feat->bit) & 1;
}
const char *
rte_cpu_get_flag_name(enum rte_cpu_flag_t feature)
{
if (feature >= RTE_CPUFLAG_NUMFLAGS)
return NULL;
return rte_cpu_feature_table[feature].name;
}
void
rte_cpu_get_intrinsics_support(struct rte_cpu_intrinsics *intrinsics)
{
memset(intrinsics, 0, sizeof(*intrinsics));
}