xref: /openbmc/linux/arch/arm64/kernel/entry-fpsimd.S (revision b38269ec) 
1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * FP/SIMD state saving and restoring
4 *
5 * Copyright (C) 2012 ARM Ltd.
6 * Author: Catalin Marinas <catalin.marinas@arm.com>
7 */
8
9#include <linux/linkage.h>
10
11#include <asm/assembler.h>
12#include <asm/fpsimdmacros.h>
13
14/*
15 * Save the FP registers.
16 *
17 * x0 - pointer to struct fpsimd_state
18 */
19SYM_FUNC_START(fpsimd_save_state)
20	fpsimd_save x0, 8
21	ret
22SYM_FUNC_END(fpsimd_save_state)
23
24/*
25 * Load the FP registers.
26 *
27 * x0 - pointer to struct fpsimd_state
28 */
29SYM_FUNC_START(fpsimd_load_state)
30	fpsimd_restore x0, 8
31	ret
32SYM_FUNC_END(fpsimd_load_state)
33
34#ifdef CONFIG_ARM64_SVE
35
36/*
37 * Save the SVE state
38 *
39 * x0 - pointer to buffer for state
40 * x1 - pointer to storage for FPSR
41 */
42SYM_FUNC_START(sve_save_state)
43	sve_save 0, x1, 2
44	ret
45SYM_FUNC_END(sve_save_state)
46
47/*
48 * Load the SVE state
49 *
50 * x0 - pointer to buffer for state
51 * x1 - pointer to storage for FPSR
52 * x2 - VQ-1
53 */
54SYM_FUNC_START(sve_load_state)
55	sve_load 0, x1, x2, 3, x4
56	ret
57SYM_FUNC_END(sve_load_state)
58
59SYM_FUNC_START(sve_get_vl)
60	_sve_rdvl	0, 1
61	ret
62SYM_FUNC_END(sve_get_vl)
63
64SYM_FUNC_START(sve_set_vq)
65	sve_load_vq x0, x1, x2
66	ret
67SYM_FUNC_END(sve_set_vq)
68
69/*
70 * Load SVE state from FPSIMD state.
71 *
72 * x0 = pointer to struct fpsimd_state
73 * x1 = VQ - 1
74 *
75 * Each SVE vector will be loaded with the first 128-bits taken from FPSIMD
76 * and the rest zeroed. All the other SVE registers will be zeroed.
77 */
78SYM_FUNC_START(sve_load_from_fpsimd_state)
79	sve_load_vq	x1, x2, x3
80	fpsimd_restore	x0, 8
81	sve_flush_p_ffr
82	ret
83SYM_FUNC_END(sve_load_from_fpsimd_state)
84
85/*
86 * Zero all SVE registers but the first 128-bits of each vector
87 *
88 * VQ must already be configured by caller, any further updates of VQ
89 * will need to ensure that the register state remains valid.
90 *
91 * x0 = VQ - 1
92 */
93SYM_FUNC_START(sve_flush_live)
94	cbz		x0, 1f	// A VQ-1 of 0 is 128 bits so no extra Z state
95	sve_flush_z
961:	sve_flush_p_ffr
97	ret
98SYM_FUNC_END(sve_flush_live)
99
100#endif /* CONFIG_ARM64_SVE */
101