linux-stable/arch/arm64/kernel/entry-fpsimd.S
Mark Brown 95fcec7132 arm64/sme: Implement context switching for ZT0
When the system supports SME2 the ZT0 register must be context switched as
part of the floating point state. This register is stored immediately
after ZA in memory and is only accessible when PSTATE.ZA is set so we
handle it in the same functions we use to save and restore ZA.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20221208-arm64-sme2-v4-10-f2fa0aef982f@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2023-01-20 12:23:06 +00:00

135 lines
2.4 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 */
#ifdef CONFIG_ARM64_SME
SYM_FUNC_START(sme_get_vl)
_sme_rdsvl 0, 1
ret
SYM_FUNC_END(sme_get_vl)
SYM_FUNC_START(sme_set_vq)
sme_load_vq x0, x1, x2
ret
SYM_FUNC_END(sme_set_vq)
/*
* Save the ZA and ZT state
*
* x0 - pointer to buffer for state
* x1 - number of ZT registers to save
*/
SYM_FUNC_START(sme_save_state)
_sme_rdsvl 2, 1 // x2 = VL/8
sme_save_za 0, x2, 12 // Leaves x0 pointing to the end of ZA
cbz x1, 1f
_str_zt 0
1:
ret
SYM_FUNC_END(sme_save_state)
/*
* Load the ZA and ZT state
*
* x0 - pointer to buffer for state
* x1 - number of ZT registers to save
*/
SYM_FUNC_START(sme_load_state)
_sme_rdsvl 2, 1 // x2 = VL/8
sme_load_za 0, x2, 12 // Leaves x0 pointing to the end of ZA
cbz x1, 1f
_ldr_zt 0
1:
ret
SYM_FUNC_END(sme_load_state)
#endif /* CONFIG_ARM64_SME */