xref: /openbmc/linux/arch/arm64/kernel/smccc-call.S (revision 5c816641)
1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * Copyright (c) 2015, Linaro Limited
4 */
5#include <linux/linkage.h>
6#include <linux/arm-smccc.h>
7
8#include <asm/asm-offsets.h>
9#include <asm/assembler.h>
10#include <asm/thread_info.h>
11
12/*
13 * If we have SMCCC v1.3 and (as is likely) no SVE state in
14 * the registers then set the SMCCC hint bit to say there's no
15 * need to preserve it.  Do this by directly adjusting the SMCCC
16 * function value which is already stored in x0 ready to be called.
17 */
18SYM_FUNC_START(__arm_smccc_sve_check)
19
20	ldr_l	x16, smccc_has_sve_hint
21	cbz	x16, 2f
22
23	get_current_task x16
24	ldr	x16, [x16, #TSK_TI_FLAGS]
25	tbnz	x16, #TIF_FOREIGN_FPSTATE, 1f	// Any live FP state?
26	tbnz	x16, #TIF_SVE, 2f		// Does that state include SVE?
27
281:	orr	x0, x0, ARM_SMCCC_1_3_SVE_HINT
29
302:	ret
31SYM_FUNC_END(__arm_smccc_sve_check)
32EXPORT_SYMBOL(__arm_smccc_sve_check)
33
34	.macro SMCCC instr
35	stp     x29, x30, [sp, #-16]!
36	mov	x29, sp
37alternative_if ARM64_SVE
38	bl	__arm_smccc_sve_check
39alternative_else_nop_endif
40	\instr	#0
41	ldr	x4, [sp, #16]
42	stp	x0, x1, [x4, #ARM_SMCCC_RES_X0_OFFS]
43	stp	x2, x3, [x4, #ARM_SMCCC_RES_X2_OFFS]
44	ldr	x4, [sp, #24]
45	cbz	x4, 1f /* no quirk structure */
46	ldr	x9, [x4, #ARM_SMCCC_QUIRK_ID_OFFS]
47	cmp	x9, #ARM_SMCCC_QUIRK_QCOM_A6
48	b.ne	1f
49	str	x6, [x4, ARM_SMCCC_QUIRK_STATE_OFFS]
501:	ldp     x29, x30, [sp], #16
51	ret
52	.endm
53
54/*
55 * void arm_smccc_smc(unsigned long a0, unsigned long a1, unsigned long a2,
56 *		  unsigned long a3, unsigned long a4, unsigned long a5,
57 *		  unsigned long a6, unsigned long a7, struct arm_smccc_res *res,
58 *		  struct arm_smccc_quirk *quirk)
59 */
60SYM_FUNC_START(__arm_smccc_smc)
61	SMCCC	smc
62SYM_FUNC_END(__arm_smccc_smc)
63EXPORT_SYMBOL(__arm_smccc_smc)
64
65/*
66 * void arm_smccc_hvc(unsigned long a0, unsigned long a1, unsigned long a2,
67 *		  unsigned long a3, unsigned long a4, unsigned long a5,
68 *		  unsigned long a6, unsigned long a7, struct arm_smccc_res *res,
69 *		  struct arm_smccc_quirk *quirk)
70 */
71SYM_FUNC_START(__arm_smccc_hvc)
72	SMCCC	hvc
73SYM_FUNC_END(__arm_smccc_hvc)
74EXPORT_SYMBOL(__arm_smccc_hvc)
75
76	.macro SMCCC_1_2 instr
77	/* Save `res` and free a GPR that won't be clobbered */
78	stp     x1, x19, [sp, #-16]!
79
80	/* Ensure `args` won't be clobbered while loading regs in next step */
81	mov	x19, x0
82
83	/* Load the registers x0 - x17 from the struct arm_smccc_1_2_regs */
84	ldp	x0, x1, [x19, #ARM_SMCCC_1_2_REGS_X0_OFFS]
85	ldp	x2, x3, [x19, #ARM_SMCCC_1_2_REGS_X2_OFFS]
86	ldp	x4, x5, [x19, #ARM_SMCCC_1_2_REGS_X4_OFFS]
87	ldp	x6, x7, [x19, #ARM_SMCCC_1_2_REGS_X6_OFFS]
88	ldp	x8, x9, [x19, #ARM_SMCCC_1_2_REGS_X8_OFFS]
89	ldp	x10, x11, [x19, #ARM_SMCCC_1_2_REGS_X10_OFFS]
90	ldp	x12, x13, [x19, #ARM_SMCCC_1_2_REGS_X12_OFFS]
91	ldp	x14, x15, [x19, #ARM_SMCCC_1_2_REGS_X14_OFFS]
92	ldp	x16, x17, [x19, #ARM_SMCCC_1_2_REGS_X16_OFFS]
93
94	\instr #0
95
96	/* Load the `res` from the stack */
97	ldr	x19, [sp]
98
99	/* Store the registers x0 - x17 into the result structure */
100	stp	x0, x1, [x19, #ARM_SMCCC_1_2_REGS_X0_OFFS]
101	stp	x2, x3, [x19, #ARM_SMCCC_1_2_REGS_X2_OFFS]
102	stp	x4, x5, [x19, #ARM_SMCCC_1_2_REGS_X4_OFFS]
103	stp	x6, x7, [x19, #ARM_SMCCC_1_2_REGS_X6_OFFS]
104	stp	x8, x9, [x19, #ARM_SMCCC_1_2_REGS_X8_OFFS]
105	stp	x10, x11, [x19, #ARM_SMCCC_1_2_REGS_X10_OFFS]
106	stp	x12, x13, [x19, #ARM_SMCCC_1_2_REGS_X12_OFFS]
107	stp	x14, x15, [x19, #ARM_SMCCC_1_2_REGS_X14_OFFS]
108	stp	x16, x17, [x19, #ARM_SMCCC_1_2_REGS_X16_OFFS]
109
110	/* Restore original x19 */
111	ldp     xzr, x19, [sp], #16
112	ret
113.endm
114
115/*
116 * void arm_smccc_1_2_hvc(const struct arm_smccc_1_2_regs *args,
117 *			  struct arm_smccc_1_2_regs *res);
118 */
119SYM_FUNC_START(arm_smccc_1_2_hvc)
120	SMCCC_1_2 hvc
121SYM_FUNC_END(arm_smccc_1_2_hvc)
122EXPORT_SYMBOL(arm_smccc_1_2_hvc)
123
124/*
125 * void arm_smccc_1_2_smc(const struct arm_smccc_1_2_regs *args,
126 *			  struct arm_smccc_1_2_regs *res);
127 */
128SYM_FUNC_START(arm_smccc_1_2_smc)
129	SMCCC_1_2 smc
130SYM_FUNC_END(arm_smccc_1_2_smc)
131EXPORT_SYMBOL(arm_smccc_1_2_smc)
132