1/* SPDX-License-Identifier: GPL-2.0
2 *
3 * Copyright (c) 2018 Chen-Yu Tsai
4 * Copyright (c) 2018 Bootlin
5 *
6 * Chen-Yu Tsai <wens@csie.org>
7 * Mylène Josserand <mylene.josserand@bootlin.com>
8 *
9 * SMP support for sunxi based systems with Cortex A7/A15
10 *
11 */
12
13#include <linux/linkage.h>
14#include <asm/assembler.h>
15#include <asm/cputype.h>
16
17ENTRY(sunxi_mc_smp_cluster_cache_enable)
18 .arch armv7-a
19 /*
20 * Enable cluster-level coherency, in preparation for turning on the MMU.
21 *
22 * Also enable regional clock gating and L2 data latency settings for
23 * Cortex-A15. These settings are from the vendor kernel.
24 */
25 mrc p15, 0, r1, c0, c0, 0
26 movw r2, #(ARM_CPU_PART_MASK & 0xffff)
27 movt r2, #(ARM_CPU_PART_MASK >> 16)
28 and r1, r1, r2
29 movw r2, #(ARM_CPU_PART_CORTEX_A15 & 0xffff)
30 movt r2, #(ARM_CPU_PART_CORTEX_A15 >> 16)
31 cmp r1, r2
32 bne not_a15
33
34 /* The following is Cortex-A15 specific */
35
36 /* ACTLR2: Enable CPU regional clock gates */
37 mrc p15, 1, r1, c15, c0, 4
38 orr r1, r1, #(0x1 << 31)
39 mcr p15, 1, r1, c15, c0, 4
40
41 /* L2ACTLR */
42 mrc p15, 1, r1, c15, c0, 0
43 /* Enable L2, GIC, and Timer regional clock gates */
44 orr r1, r1, #(0x1 << 26)
45 /* Disable clean/evict from being pushed to external */
46 orr r1, r1, #(0x1<<3)
47 mcr p15, 1, r1, c15, c0, 0
48
49 /* L2CTRL: L2 data RAM latency */
50 mrc p15, 1, r1, c9, c0, 2
51 bic r1, r1, #(0x7 << 0)
52 orr r1, r1, #(0x3 << 0)
53 mcr p15, 1, r1, c9, c0, 2
54
55 /* End of Cortex-A15 specific setup */
56 not_a15:
57
58 /* Get value of sunxi_mc_smp_first_comer */
59 adr r1, first
60 ldr r0, [r1]
61 ldr r0, [r1, r0]
62
63 /* Skip cci_enable_port_for_self if not first comer */
64 cmp r0, #0
65 bxeq lr
66 b cci_enable_port_for_self
67
68 .align 2
69 first: .word sunxi_mc_smp_first_comer - .
70ENDPROC(sunxi_mc_smp_cluster_cache_enable)
71
72ENTRY(sunxi_mc_smp_secondary_startup)
73 bl sunxi_mc_smp_cluster_cache_enable
74 bl secure_cntvoff_init
75 b secondary_startup
76ENDPROC(sunxi_mc_smp_secondary_startup)
77
78ENTRY(sunxi_mc_smp_resume)
79 bl sunxi_mc_smp_cluster_cache_enable
80 b cpu_resume
81ENDPROC(sunxi_mc_smp_resume)
82

source code of linux/arch/arm/mach-sunxi/headsmp.S