linux/arch/arm64/kernel/entry-fpsimd.S
Mark Brown ddc806b5c4 arm64/sve: Explicitly load vector length when restoring SVE state
Currently when restoring the SVE state we supply the SVE vector length
as an argument to sve_load_state() and the underlying macros. This becomes
inconvenient with the addition of SME since we may need to restore any
combination of SVE and SME vector lengths, and we already separately
restore the vector length in the KVM code. We don't need to know the vector
length during the actual register load since the SME load instructions can
index into the data array for us.

Refactor the interface so we explicitly set the vector length separately
to restoring the SVE registers in preparation for adding SME support, no
functional change should be involved.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20211019172247.3045838-9-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2021-10-21 10:18:17 +01:00

89 lines
1.6 KiB
ArmAsm

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* FP/SIMD state saving and restoring
*
* Copyright (C) 2012 ARM Ltd.
* Author: Catalin Marinas <catalin.marinas@arm.com>
*/
#include <linux/linkage.h>
#include <asm/assembler.h>
#include <asm/fpsimdmacros.h>
/*
* Save the FP registers.
*
* x0 - pointer to struct fpsimd_state
*/
SYM_FUNC_START(fpsimd_save_state)
fpsimd_save x0, 8
ret
SYM_FUNC_END(fpsimd_save_state)
/*
* Load the FP registers.
*
* x0 - pointer to struct fpsimd_state
*/
SYM_FUNC_START(fpsimd_load_state)
fpsimd_restore x0, 8
ret
SYM_FUNC_END(fpsimd_load_state)
#ifdef CONFIG_ARM64_SVE
/*
* Save the SVE state
*
* x0 - pointer to buffer for state
* x1 - pointer to storage for FPSR
* x2 - Save FFR if non-zero
*/
SYM_FUNC_START(sve_save_state)
sve_save 0, x1, x2, 3
ret
SYM_FUNC_END(sve_save_state)
/*
* Load the SVE state
*
* x0 - pointer to buffer for state
* x1 - pointer to storage for FPSR
* x2 - Restore FFR if non-zero
*/
SYM_FUNC_START(sve_load_state)
sve_load 0, x1, x2, 4
ret
SYM_FUNC_END(sve_load_state)
SYM_FUNC_START(sve_get_vl)
_sve_rdvl 0, 1
ret
SYM_FUNC_END(sve_get_vl)
SYM_FUNC_START(sve_set_vq)
sve_load_vq x0, x1, x2
ret
SYM_FUNC_END(sve_set_vq)
/*
* Zero all SVE registers but the first 128-bits of each vector
*
* VQ must already be configured by caller, any further updates of VQ
* will need to ensure that the register state remains valid.
*
* x0 = include FFR?
* x1 = VQ - 1
*/
SYM_FUNC_START(sve_flush_live)
cbz x1, 1f // A VQ-1 of 0 is 128 bits so no extra Z state
sve_flush_z
1: sve_flush_p
tbz x0, #0, 2f
sve_flush_ffr
2: ret
SYM_FUNC_END(sve_flush_live)
#endif /* CONFIG_ARM64_SVE */