1/*
2 * Coherency fabric: low level functions
3 *
4 * Copyright (C) 2012 Marvell
5 *
6 * Gregory CLEMENT <gregory.clement@free-electrons.com>
7 *
8 * This file is licensed under the terms of the GNU General Public
9 * License version 2.  This program is licensed "as is" without any
10 * warranty of any kind, whether express or implied.
11 *
12 * This file implements the assembly function to add a CPU to the
13 * coherency fabric. This function is called by each of the secondary
14 * CPUs during their early boot in an SMP kernel, this why this
15 * function have to callable from assembly. It can also be called by a
16 * primary CPU from C code during its boot.
17 */
18
19#include <linux/linkage.h>
20#define ARMADA_XP_CFB_CTL_REG_OFFSET 0x0
21#define ARMADA_XP_CFB_CFG_REG_OFFSET 0x4
22
23	.text
24/*
25 * r0: Coherency fabric base register address
26 * r1: HW CPU id
27 */
28ENTRY(ll_set_cpu_coherent)
29	/* Create bit by cpu index */
30	mov	r3, #(1 << 24)
31	lsl	r1, r3, r1
32
33	/* Add CPU to SMP group - Atomic */
34	add	r3, r0, #ARMADA_XP_CFB_CTL_REG_OFFSET
351:
36	ldrex	r2, [r3]
37	orr	r2, r2, r1
38	strex 	r0, r2, [r3]
39	cmp	r0, #0
40	bne 1b
41
42	/* Enable coherency on CPU - Atomic */
43	add	r3, r3, #ARMADA_XP_CFB_CFG_REG_OFFSET
441:
45	ldrex	r2, [r3]
46	orr	r2, r2, r1
47	strex	r0, r2, [r3]
48	cmp	r0, #0
49	bne 1b
50
51	dsb
52
53	mov	r0, #0
54	mov	pc, lr
55ENDPROC(ll_set_cpu_coherent)
56