1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * Copyright (c) 2021 Western Digital Corporation or its affiliates.
4 * Copyright (c) 2022 Ventana Micro Systems Inc.
5 */
6
7#include <linux/linkage.h>
8#include <asm/asm.h>
9#include <asm/asm-offsets.h>
10#include <asm/csr.h>
11
12	.text
13	.altmacro
14	.option norelax
15
16ENTRY(__cpu_suspend_enter)
17	/* Save registers (except A0 and T0-T6) */
18	REG_S	ra, (SUSPEND_CONTEXT_REGS + PT_RA)(a0)
19	REG_S	sp, (SUSPEND_CONTEXT_REGS + PT_SP)(a0)
20	REG_S	gp, (SUSPEND_CONTEXT_REGS + PT_GP)(a0)
21	REG_S	tp, (SUSPEND_CONTEXT_REGS + PT_TP)(a0)
22	REG_S	s0, (SUSPEND_CONTEXT_REGS + PT_S0)(a0)
23	REG_S	s1, (SUSPEND_CONTEXT_REGS + PT_S1)(a0)
24	REG_S	a1, (SUSPEND_CONTEXT_REGS + PT_A1)(a0)
25	REG_S	a2, (SUSPEND_CONTEXT_REGS + PT_A2)(a0)
26	REG_S	a3, (SUSPEND_CONTEXT_REGS + PT_A3)(a0)
27	REG_S	a4, (SUSPEND_CONTEXT_REGS + PT_A4)(a0)
28	REG_S	a5, (SUSPEND_CONTEXT_REGS + PT_A5)(a0)
29	REG_S	a6, (SUSPEND_CONTEXT_REGS + PT_A6)(a0)
30	REG_S	a7, (SUSPEND_CONTEXT_REGS + PT_A7)(a0)
31	REG_S	s2, (SUSPEND_CONTEXT_REGS + PT_S2)(a0)
32	REG_S	s3, (SUSPEND_CONTEXT_REGS + PT_S3)(a0)
33	REG_S	s4, (SUSPEND_CONTEXT_REGS + PT_S4)(a0)
34	REG_S	s5, (SUSPEND_CONTEXT_REGS + PT_S5)(a0)
35	REG_S	s6, (SUSPEND_CONTEXT_REGS + PT_S6)(a0)
36	REG_S	s7, (SUSPEND_CONTEXT_REGS + PT_S7)(a0)
37	REG_S	s8, (SUSPEND_CONTEXT_REGS + PT_S8)(a0)
38	REG_S	s9, (SUSPEND_CONTEXT_REGS + PT_S9)(a0)
39	REG_S	s10, (SUSPEND_CONTEXT_REGS + PT_S10)(a0)
40	REG_S	s11, (SUSPEND_CONTEXT_REGS + PT_S11)(a0)
41
42	/* Save CSRs */
43	csrr	t0, CSR_EPC
44	REG_S	t0, (SUSPEND_CONTEXT_REGS + PT_EPC)(a0)
45	csrr	t0, CSR_STATUS
46	REG_S	t0, (SUSPEND_CONTEXT_REGS + PT_STATUS)(a0)
47	csrr	t0, CSR_TVAL
48	REG_S	t0, (SUSPEND_CONTEXT_REGS + PT_BADADDR)(a0)
49	csrr	t0, CSR_CAUSE
50	REG_S	t0, (SUSPEND_CONTEXT_REGS + PT_CAUSE)(a0)
51
52	/* Return non-zero value */
53	li	a0, 1
54
55	/* Return to C code */
56	ret
57END(__cpu_suspend_enter)
58
59ENTRY(__cpu_resume_enter)
60	/* Load the global pointer */
61	.option push
62	.option norelax
63		la gp, __global_pointer$
64	.option pop
65
66#ifdef CONFIG_MMU
67	/* Save A0 and A1 */
68	add	t0, a0, zero
69	add	t1, a1, zero
70
71	/* Enable MMU */
72	la	a0, swapper_pg_dir
73	XIP_FIXUP_OFFSET a0
74	call	relocate_enable_mmu
75
76	/* Restore A0 and A1 */
77	add	a0, t0, zero
78	add	a1, t1, zero
79#endif
80
81	/* Make A0 point to suspend context */
82	add	a0, a1, zero
83
84	/* Restore CSRs */
85	REG_L	t0, (SUSPEND_CONTEXT_REGS + PT_EPC)(a0)
86	csrw	CSR_EPC, t0
87	REG_L	t0, (SUSPEND_CONTEXT_REGS + PT_STATUS)(a0)
88	csrw	CSR_STATUS, t0
89	REG_L	t0, (SUSPEND_CONTEXT_REGS + PT_BADADDR)(a0)
90	csrw	CSR_TVAL, t0
91	REG_L	t0, (SUSPEND_CONTEXT_REGS + PT_CAUSE)(a0)
92	csrw	CSR_CAUSE, t0
93
94	/* Restore registers (except A0 and T0-T6) */
95	REG_L	ra, (SUSPEND_CONTEXT_REGS + PT_RA)(a0)
96	REG_L	sp, (SUSPEND_CONTEXT_REGS + PT_SP)(a0)
97	REG_L	gp, (SUSPEND_CONTEXT_REGS + PT_GP)(a0)
98	REG_L	tp, (SUSPEND_CONTEXT_REGS + PT_TP)(a0)
99	REG_L	s0, (SUSPEND_CONTEXT_REGS + PT_S0)(a0)
100	REG_L	s1, (SUSPEND_CONTEXT_REGS + PT_S1)(a0)
101	REG_L	a1, (SUSPEND_CONTEXT_REGS + PT_A1)(a0)
102	REG_L	a2, (SUSPEND_CONTEXT_REGS + PT_A2)(a0)
103	REG_L	a3, (SUSPEND_CONTEXT_REGS + PT_A3)(a0)
104	REG_L	a4, (SUSPEND_CONTEXT_REGS + PT_A4)(a0)
105	REG_L	a5, (SUSPEND_CONTEXT_REGS + PT_A5)(a0)
106	REG_L	a6, (SUSPEND_CONTEXT_REGS + PT_A6)(a0)
107	REG_L	a7, (SUSPEND_CONTEXT_REGS + PT_A7)(a0)
108	REG_L	s2, (SUSPEND_CONTEXT_REGS + PT_S2)(a0)
109	REG_L	s3, (SUSPEND_CONTEXT_REGS + PT_S3)(a0)
110	REG_L	s4, (SUSPEND_CONTEXT_REGS + PT_S4)(a0)
111	REG_L	s5, (SUSPEND_CONTEXT_REGS + PT_S5)(a0)
112	REG_L	s6, (SUSPEND_CONTEXT_REGS + PT_S6)(a0)
113	REG_L	s7, (SUSPEND_CONTEXT_REGS + PT_S7)(a0)
114	REG_L	s8, (SUSPEND_CONTEXT_REGS + PT_S8)(a0)
115	REG_L	s9, (SUSPEND_CONTEXT_REGS + PT_S9)(a0)
116	REG_L	s10, (SUSPEND_CONTEXT_REGS + PT_S10)(a0)
117	REG_L	s11, (SUSPEND_CONTEXT_REGS + PT_S11)(a0)
118
119	/* Return zero value */
120	add	a0, zero, zero
121
122	/* Return to C code */
123	ret
124END(__cpu_resume_enter)
125