1/*
 2 *  linux/arch/arm/vfp/entry.S
 3 *
 4 *  Copyright (C) 2004 ARM Limited.
 5 *  Written by Deep Blue Solutions Limited.
 6 *
 7 * This program is free software; you can redistribute it and/or modify
 8 * it under the terms of the GNU General Public License version 2 as
 9 * published by the Free Software Foundation.
10 */
11#include <asm/thread_info.h>
12#include <asm/vfpmacros.h>
13#include "../kernel/entry-header.S"
14
15@ VFP entry point.
16@
17@  r0  = instruction opcode (32-bit ARM or two 16-bit Thumb)
18@  r2  = PC value to resume execution after successful emulation
19@  r9  = normal "successful" return address
20@  r10 = this threads thread_info structure
21@  lr  = unrecognised instruction return address
22@  IRQs disabled.
23@
24ENTRY(do_vfp)
25#ifdef CONFIG_PREEMPT
26	ldr	r4, [r10, #TI_PREEMPT]	@ get preempt count
27	add	r11, r4, #1		@ increment it
28	str	r11, [r10, #TI_PREEMPT]
29#endif
30	enable_irq
31 	ldr	r4, .LCvfp
32	ldr	r11, [r10, #TI_CPU]	@ CPU number
33	add	r10, r10, #TI_VFPSTATE	@ r10 = workspace
34	ldr	pc, [r4]		@ call VFP entry point
35ENDPROC(do_vfp)
36
37ENTRY(vfp_null_entry)
38#ifdef CONFIG_PREEMPT
39	get_thread_info	r10
40	ldr	r4, [r10, #TI_PREEMPT]	@ get preempt count
41	sub	r11, r4, #1		@ decrement it
42	str	r11, [r10, #TI_PREEMPT]
43#endif
44	mov	pc, lr
45ENDPROC(vfp_null_entry)
46
47	.align	2
48.LCvfp:
49	.word	vfp_vector
50
51@ This code is called if the VFP does not exist. It needs to flag the
52@ failure to the VFP initialisation code.
53
54	__INIT
55ENTRY(vfp_testing_entry)
56#ifdef CONFIG_PREEMPT
57	get_thread_info	r10
58	ldr	r4, [r10, #TI_PREEMPT]	@ get preempt count
59	sub	r11, r4, #1		@ decrement it
60	str	r11, [r10, #TI_PREEMPT]
61#endif
62	ldr	r0, VFP_arch_address
63	str	r5, [r0]		@ known non-zero value
64	mov	pc, r9			@ we have handled the fault
65ENDPROC(vfp_testing_entry)
66
67	.align	2
68VFP_arch_address:
69	.word	VFP_arch
70
71	__FINIT