xref: /openbmc/linux/arch/arm/vfp/vfphw.S (revision 6db6b729) 
1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 *  linux/arch/arm/vfp/vfphw.S
4 *
5 *  Copyright (C) 2004 ARM Limited.
6 *  Written by Deep Blue Solutions Limited.
7 */
8#include <linux/init.h>
9#include <linux/linkage.h>
10#include <asm/thread_info.h>
11#include <asm/vfpmacros.h>
12#include <linux/kern_levels.h>
13#include <asm/assembler.h>
14#include <asm/asm-offsets.h>
15
16	.macro  DBGSTR1, str, arg
17#ifdef DEBUG
18	stmfd	sp!, {r0-r3, ip, lr}
19	mov	r1, \arg
20	ldr	r0, =1f
21	bl	_printk
22	ldmfd	sp!, {r0-r3, ip, lr}
23
24	.pushsection .rodata, "a"
251:	.ascii	KERN_DEBUG "VFP: \str\n"
26	.byte	0
27	.previous
28#endif
29	.endm
30
31ENTRY(vfp_load_state)
32	@ Load the current VFP state
33	@ r0 - load location
34	@ returns FPEXC
35	DBGSTR1	"load VFP state %p", r0
36					@ Load the saved state back into the VFP
37	VFPFLDMIA r0, r1		@ reload the working registers while
38					@ FPEXC is in a safe state
39	ldmia	r0, {r0-r3}		@ load FPEXC, FPSCR, FPINST, FPINST2
40	tst	r0, #FPEXC_EX		@ is there additional state to restore?
41	beq	1f
42	VFPFMXR	FPINST, r2		@ restore FPINST (only if FPEXC.EX is set)
43	tst	r0, #FPEXC_FP2V		@ is there an FPINST2 to write?
44	beq	1f
45	VFPFMXR	FPINST2, r3		@ FPINST2 if needed (and present)
461:
47	VFPFMXR	FPSCR, r1		@ restore status
48	ret	lr
49ENDPROC(vfp_load_state)
50
51ENTRY(vfp_save_state)
52	@ Save the current VFP state
53	@ r0 - save location
54	@ r1 - FPEXC
55	DBGSTR1	"save VFP state %p", r0
56	VFPFSTMIA r0, r2		@ save the working registers
57	VFPFMRX	r2, FPSCR		@ current status
58	tst	r1, #FPEXC_EX		@ is there additional state to save?
59	beq	1f
60	VFPFMRX	r3, FPINST		@ FPINST (only if FPEXC.EX is set)
61	tst	r1, #FPEXC_FP2V		@ is there an FPINST2 to read?
62	beq	1f
63	VFPFMRX	r12, FPINST2		@ FPINST2 if needed (and present)
641:
65	stmia	r0, {r1, r2, r3, r12}	@ save FPEXC, FPSCR, FPINST, FPINST2
66	ret	lr
67ENDPROC(vfp_save_state)
68
69	.macro	tbl_branch, base, tmp, shift
70#ifdef CONFIG_THUMB2_KERNEL
71	adr	\tmp, 1f
72	add	\tmp, \tmp, \base, lsl \shift
73	ret	\tmp
74#else
75	add	pc, pc, \base, lsl \shift
76	mov	r0, r0
77#endif
781:
79	.endm
80
81ENTRY(vfp_get_float)
82	tbl_branch r0, r3, #3
83	.fpu	vfpv2
84	.irp	dr,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15
851:	vmov	r0, s\dr
86	ret	lr
87	.org	1b + 8
88	.endr
89	.irp	dr,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31
901:	vmov	r0, s\dr
91	ret	lr
92	.org	1b + 8
93	.endr
94ENDPROC(vfp_get_float)
95
96ENTRY(vfp_put_float)
97	tbl_branch r1, r3, #3
98	.fpu	vfpv2
99	.irp	dr,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15
1001:	vmov	s\dr, r0
101	ret	lr
102	.org	1b + 8
103	.endr
104	.irp	dr,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31
1051:	vmov	s\dr, r0
106	ret	lr
107	.org	1b + 8
108	.endr
109ENDPROC(vfp_put_float)
110
111ENTRY(vfp_get_double)
112	tbl_branch r0, r3, #3
113	.fpu	vfpv2
114	.irp	dr,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15
1151:	vmov	r0, r1, d\dr
116	ret	lr
117	.org	1b + 8
118	.endr
119#ifdef CONFIG_VFPv3
120	@ d16 - d31 registers
121	.fpu	vfpv3
122	.irp	dr,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31
1231:	vmov	r0, r1, d\dr
124	ret	lr
125	.org	1b + 8
126	.endr
127#endif
128
129	@ virtual register 16 (or 32 if VFPv3) for compare with zero
130	mov	r0, #0
131	mov	r1, #0
132	ret	lr
133ENDPROC(vfp_get_double)
134
135ENTRY(vfp_put_double)
136	tbl_branch r2, r3, #3
137	.fpu	vfpv2
138	.irp	dr,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15
1391:	vmov	d\dr, r0, r1
140	ret	lr
141	.org	1b + 8
142	.endr
143#ifdef CONFIG_VFPv3
144	.fpu	vfpv3
145	@ d16 - d31 registers
146	.irp	dr,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31
1471:	vmov	d\dr, r0, r1
148	ret	lr
149	.org	1b + 8
150	.endr
151#endif
152ENDPROC(vfp_put_double)
153