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