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torvalds
GitHub Repository: torvalds/linux
 Path: blob/master/arch/arm64/kernel/entry-fpsimd.S
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/* SPDX-License-Identifier: GPL-2.0-only */

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/*

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 * FP/SIMD state saving and restoring

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 *

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 * Copyright (C) 2012 ARM Ltd.

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 * Author: Catalin Marinas <[email protected]>

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 */

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#include <linux/linkage.h>

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#include <asm/assembler.h>

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#include <asm/fpsimdmacros.h>

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/*

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 * Save the FP registers.

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 *

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 * x0 - pointer to struct fpsimd_state

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 */

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SYM_FUNC_START(fpsimd_save_state)

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	fpsimd_save x0, 8

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	ret

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SYM_FUNC_END(fpsimd_save_state)

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/*

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 * Load the FP registers.

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 *

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 * x0 - pointer to struct fpsimd_state

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 */

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SYM_FUNC_START(fpsimd_load_state)

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	fpsimd_restore x0, 8

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	ret

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SYM_FUNC_END(fpsimd_load_state)

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#ifdef CONFIG_ARM64_SVE

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/*

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 * Save the SVE state

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 *

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 * x0 - pointer to buffer for state

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 * x1 - pointer to storage for FPSR

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 * x2 - Save FFR if non-zero

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 */

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SYM_FUNC_START(sve_save_state)

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	sve_save 0, x1, x2, 3

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	ret

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SYM_FUNC_END(sve_save_state)

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/*

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 * Load the SVE state

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 *

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 * x0 - pointer to buffer for state

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 * x1 - pointer to storage for FPSR

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 * x2 - Restore FFR if non-zero

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 */

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SYM_FUNC_START(sve_load_state)

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	sve_load 0, x1, x2, 4

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	ret

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SYM_FUNC_END(sve_load_state)

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SYM_FUNC_START(sve_get_vl)

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	_sve_rdvl	0, 1

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	ret

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SYM_FUNC_END(sve_get_vl)

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SYM_FUNC_START(sve_set_vq)

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	sve_load_vq x0, x1, x2

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	ret

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SYM_FUNC_END(sve_set_vq)

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/*

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 * Zero all SVE registers but the first 128-bits of each vector

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 *

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 * VQ must already be configured by caller, any further updates of VQ

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 * will need to ensure that the register state remains valid.

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 *

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 * x0 = include FFR?

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 * x1 = VQ - 1

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 */

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SYM_FUNC_START(sve_flush_live)

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	cbz		x1, 1f	// A VQ-1 of 0 is 128 bits so no extra Z state

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	sve_flush_z

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1:	sve_flush_p

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	tbz		x0, #0, 2f

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	sve_flush_ffr

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2:	ret

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SYM_FUNC_END(sve_flush_live)

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#endif /* CONFIG_ARM64_SVE */

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#ifdef CONFIG_ARM64_SME

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SYM_FUNC_START(sme_get_vl)

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	_sme_rdsvl	0, 1

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	ret

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SYM_FUNC_END(sme_get_vl)

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SYM_FUNC_START(sme_set_vq)

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	sme_load_vq x0, x1, x2

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	ret

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SYM_FUNC_END(sme_set_vq)

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/*

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 * Save the ZA and ZT state

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 *

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 * x0 - pointer to buffer for state

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 * x1 - number of ZT registers to save

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 */

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SYM_FUNC_START(sme_save_state)

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	_sme_rdsvl	2, 1		// x2 = VL/8

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	sme_save_za 0, x2, 12		// Leaves x0 pointing to the end of ZA

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	cbz	x1, 1f

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	_str_zt 0

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1:

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	ret

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SYM_FUNC_END(sme_save_state)

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/*

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 * Load the ZA and ZT state

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 *

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 * x0 - pointer to buffer for state

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 * x1 - number of ZT registers to save

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 */

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SYM_FUNC_START(sme_load_state)

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	_sme_rdsvl	2, 1		// x2 = VL/8

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	sme_load_za 0, x2, 12		// Leaves x0 pointing to the end of ZA

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	cbz	x1, 1f

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	_ldr_zt 0

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1:

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	ret

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SYM_FUNC_END(sme_load_state)

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#endif /* CONFIG_ARM64_SME */

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