linux/tools/testing/selftests/arm64/fp/rdvl.S

// SPDX-License-Identifier: GPL-2.0-only
// Copyright (C) 2021 ARM Limited.

.arch_extension sve

.globl rdvl_sve
rdvl_sve:
	hint	34			// BTI C
	rdvl	x0, #1
	ret
kselftest/arm64: Provide a helper binary and "library" for SVE RDVL SVE provides an instruction RDVL which reports the currently configured vector length. In order to validate that our vector length configuration interfaces are working correctly without having to build the C code for our test programs with SVE enabled provide a trivial assembly library with a C callable function that executes RDVL. Since these interfaces also control behaviour on exec() provide a trivial wrapper program which reports the currently configured vector length on stdout, tests can use this to verify that behaviour on exec() is as expected. In preparation for providing similar helper functionality for SME, the Scalable Matrix Extension, which allows separately configured vector lengths to be read back both the assembler function and wrapper binary have SVE included in their name. Signed-off-by: Mark Brown <broonie@kernel.org> Reviewed-by: Dave Martin <Dave.Martin@arm.com> Link: https://lore.kernel.org/r/20210803140450.46624-2-broonie@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> 2021-08-03 14:04:47 +00:00			`// SPDX-License-Identifier: GPL-2.0-only`
			`// Copyright (C) 2021 ARM Limited.`

			`.arch_extension sve`

			`.globl rdvl_sve`
			`rdvl_sve:`
			`hint 34 // BTI C`
			`rdvl x0, #1`
			`ret`