| // SPDX-License-Identifier: GPL-2.0-only |
| // Copyright (C) 2021 ARM Limited. |
| // Original author: Mark Brown <broonie@kernel.org> |
| // |
| // Trivial syscall overhead benchmark. |
| // |
| // This is implemented in asm to ensure that we don't have any issues with |
| // system libraries using instructions that disrupt the test. |
| |
| #include <asm/unistd.h> |
| #include "assembler.h" |
| |
| .arch_extension sve |
| |
| .macro test_loop per_loop |
| mov x10, x20 |
| mov x8, #__NR_getpid |
| mrs x11, CNTVCT_EL0 |
| 1: |
| \per_loop |
| svc #0 |
| sub x10, x10, #1 |
| cbnz x10, 1b |
| |
| mrs x12, CNTVCT_EL0 |
| sub x0, x12, x11 |
| bl putdec |
| puts "\n" |
| .endm |
| |
| // Main program entry point |
| .globl _start |
| function _start |
| _start: |
| puts "Iterations per test: " |
| mov x20, #10000 |
| lsl x20, x20, #8 |
| mov x0, x20 |
| bl putdec |
| puts "\n" |
| |
| // Test having never used SVE |
| puts "No SVE: " |
| test_loop |
| |
| // Check for SVE support - should use hwcap but that's hard in asm |
| mrs x0, ID_AA64PFR0_EL1 |
| ubfx x0, x0, #32, #4 |
| cbnz x0, 1f |
| puts "System does not support SVE\n" |
| b out |
| 1: |
| |
| // Execute a SVE instruction |
| puts "SVE VL: " |
| rdvl x0, #8 |
| bl putdec |
| puts "\n" |
| |
| puts "SVE used once: " |
| test_loop |
| |
| // Use SVE per syscall |
| puts "SVE used per syscall: " |
| test_loop "rdvl x0, #8" |
| |
| // And we're done |
| out: |
| mov x0, #0 |
| mov x8, #__NR_exit |
| svc #0 |
