xref: /rk3399_ARM-atf/lib/cpus/aarch64/cpu_helpers.S (revision 24fb838f965cc1250831cd021d6a18b0d371b853)
1/*
2 * Copyright (c) 2014, ARM Limited and Contributors. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are met:
6 *
7 * Redistributions of source code must retain the above copyright notice, this
8 * list of conditions and the following disclaimer.
9 *
10 * Redistributions in binary form must reproduce the above copyright notice,
11 * this list of conditions and the following disclaimer in the documentation
12 * and/or other materials provided with the distribution.
13 *
14 * Neither the name of ARM nor the names of its contributors may be used
15 * to endorse or promote products derived from this software without specific
16 * prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
19 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
22 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28 * POSSIBILITY OF SUCH DAMAGE.
29 */
30
31#include <arch.h>
32#include <asm_macros.S>
33#include <assert_macros.S>
34#include <cpu_macros.S>
35#if IMAGE_BL31
36#include <cpu_data.h>
37#endif
38
39 /* Reset fn is needed in BL at reset vector */
40#if IMAGE_BL1 || (IMAGE_BL31 && RESET_TO_BL31)
41	/*
42	 * The reset handler common to all platforms.  After a matching
43	 * cpu_ops structure entry is found, the correponding reset_handler
44	 * in the cpu_ops is invoked.
45	 */
46	.globl	reset_handler
47func reset_handler
48	mov	x10, x30
49
50	bl	plat_reset_handler
51
52	/* Get the matching cpu_ops pointer */
53	bl	get_cpu_ops_ptr
54#if ASM_ASSERTION
55	cmp	x0, #0
56	ASM_ASSERT(ne)
57#endif
58
59	/* Get the cpu_ops reset handler */
60	ldr	x2, [x0, #CPU_RESET_FUNC]
61	cbz	x2, 1f
62	blr	x2
631:
64	ret	x10
65
66#endif /* IMAGE_BL1 || (IMAGE_BL31 && RESET_TO_BL31) */
67
68	/*
69	 * The below function returns the cpu_ops structure matching the
70	 * midr of the core. It reads the MIDR_EL1 and finds the matching
71	 * entry in cpu_ops entries. Only the implementation and part number
72	 * are used to match the entries.
73	 * Return :
74	 *     x0 - The matching cpu_ops pointer on Success
75	 *     x0 - 0 on failure.
76	 * Clobbers : x0 - x5
77	 */
78	.globl	get_cpu_ops_ptr
79func get_cpu_ops_ptr
80	/* Get the cpu_ops start and end locations */
81	adr	x4, (__CPU_OPS_START__ + CPU_MIDR)
82	adr	x5, (__CPU_OPS_END__ + CPU_MIDR)
83
84	/* Initialize the return parameter */
85	mov	x0, #0
86
87	/* Read the MIDR_EL1 */
88	mrs	x2, midr_el1
89	mov_imm	x3, CPU_IMPL_PN_MASK
90
91	/* Retain only the implementation and part number using mask */
92	and	w2, w2, w3
931:
94	/* Check if we have reached end of list */
95	cmp	x4, x5
96	b.eq	error_exit
97
98	/* load the midr from the cpu_ops */
99	ldr	x1, [x4], #CPU_OPS_SIZE
100	and	w1, w1, w3
101
102	/* Check if midr matches to midr of this core */
103	cmp	w1, w2
104	b.ne	1b
105
106	/* Subtract the increment and offset to get the cpu-ops pointer */
107	sub	x0, x4, #(CPU_OPS_SIZE + CPU_MIDR)
108error_exit:
109	ret
110