xref: /optee_os/core/arch/arm/kernel/misc_a32.S (revision bc420748bfc44a9e09000a3966fc59e9e0219df4)
1/*
2 * Copyright (c) 2014, STMicroelectronics International N.V.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are met:
7 *
8 * 1. Redistributions of source code must retain the above copyright notice,
9 * this list of conditions and the following disclaimer.
10 *
11 * 2. Redistributions in binary form must reproduce the above copyright notice,
12 * this list of conditions and the following disclaimer in the documentation
13 * and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
16 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
19 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
20 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
21 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
22 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
23 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
24 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
25 * POSSIBILITY OF SUCH DAMAGE.
26 */
27
28#include <asm.S>
29#include <arm.h>
30#include <arm32_macros.S>
31
32/* Let platforms override this if needed */
33.weak get_core_pos
34
35FUNC get_core_pos , :
36	read_mpidr r0
37	/* Calculate CorePos = (ClusterId * 4) + CoreId */
38	and	r1, r0, #MPIDR_CPU_MASK
39	and	r0, r0, #MPIDR_CLUSTER_MASK
40	add	r0, r1, r0, LSR #6
41	bx	lr
42END_FUNC get_core_pos
43
44/*
45 * uint32_t temp_set_mode(int cpu_mode)
46 *   returns cpsr to be set
47 */
48LOCAL_FUNC temp_set_mode , :
49	mov	r1, r0
50	cmp	r1, #CPSR_MODE_USR	/* update mode: usr -> sys */
51	moveq	r1, #CPSR_MODE_SYS
52	cpsid	aif			/* disable interrupts */
53	mrs	r0, cpsr		/* get cpsr with disabled its*/
54	bic	r0, #CPSR_MODE_MASK	/* clear mode */
55	orr	r0, r1			/* set expected mode */
56	bx	lr
57END_FUNC temp_set_mode
58
59/* uint32_t read_mode_sp(int cpu_mode) */
60FUNC read_mode_sp , :
61	push	{r4, lr}
62	mrs	r4, cpsr		/* save cpsr */
63	bl	temp_set_mode
64	msr	cpsr, r0		/* set the new mode */
65	mov	r0, sp			/* get the function result */
66	msr	cpsr, r4		/* back to the old mode */
67	pop	{r4, pc}
68END_FUNC read_mode_sp
69
70/* uint32_t read_mode_lr(int cpu_mode) */
71FUNC read_mode_lr , :
72	push	{r4, lr}
73	mrs	r4, cpsr		/* save cpsr */
74	bl	temp_set_mode
75	msr	cpsr, r0		/* set the new mode */
76	mov	r0, lr			/* get the function result */
77	msr	cpsr, r4		/* back to the old mode */
78	pop	{r4, pc}
79END_FUNC read_mode_lr
80