1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
|
From 6f5002c91f35f6b171bc608b87b3f2b55451f32b Mon Sep 17 00:00:00 2001
From: Maxime Ripard <maxime.ripard@free-electrons.com>
Date: Sun, 3 Nov 2013 10:30:13 +0100
Subject: [PATCH] ARM: sun6i: Add SMP support for the Allwinner A31
The A31 is a quad Cortex-A7. Add the logic to use the IPs used to
control the CPU configuration and the CPU power so that we can bring up
secondary CPUs at boot.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
arch/arm/mach-sunxi/Makefile | 1 +
arch/arm/mach-sunxi/common.h | 19 +++++++
arch/arm/mach-sunxi/headsmp.S | 9 +++
arch/arm/mach-sunxi/platsmp.c | 124 ++++++++++++++++++++++++++++++++++++++++++
arch/arm/mach-sunxi/sunxi.c | 3 +
5 files changed, 156 insertions(+)
create mode 100644 arch/arm/mach-sunxi/common.h
create mode 100644 arch/arm/mach-sunxi/headsmp.S
create mode 100644 arch/arm/mach-sunxi/platsmp.c
diff --git a/arch/arm/mach-sunxi/Makefile b/arch/arm/mach-sunxi/Makefile
index 93bebfc..d939720 100644
--- a/arch/arm/mach-sunxi/Makefile
+++ b/arch/arm/mach-sunxi/Makefile
@@ -1 +1,2 @@
obj-$(CONFIG_ARCH_SUNXI) += sunxi.o
+obj-$(CONFIG_SMP) += platsmp.o headsmp.o
diff --git a/arch/arm/mach-sunxi/common.h b/arch/arm/mach-sunxi/common.h
new file mode 100644
index 0000000..9e5ac47
--- /dev/null
+++ b/arch/arm/mach-sunxi/common.h
@@ -0,0 +1,19 @@
+/*
+ * Core functions for Allwinner SoCs
+ *
+ * Copyright (C) 2013 Maxime Ripard
+ *
+ * Maxime Ripard <maxime.ripard@free-electrons.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#ifndef __ARCH_SUNXI_COMMON_H_
+#define __ARCH_SUNXI_COMMON_H_
+
+void sun6i_secondary_startup(void);
+extern struct smp_operations sun6i_smp_ops;
+
+#endif /* __ARCH_SUNXI_COMMON_H_ */
diff --git a/arch/arm/mach-sunxi/headsmp.S b/arch/arm/mach-sunxi/headsmp.S
new file mode 100644
index 0000000..a10d494
--- /dev/null
+++ b/arch/arm/mach-sunxi/headsmp.S
@@ -0,0 +1,9 @@
+#include <linux/linkage.h>
+#include <linux/init.h>
+
+ .section ".text.head", "ax"
+
+ENTRY(sun6i_secondary_startup)
+ msr cpsr_fsxc, #0xd3
+ b secondary_startup
+ENDPROC(sun6i_secondary_startup)
diff --git a/arch/arm/mach-sunxi/platsmp.c b/arch/arm/mach-sunxi/platsmp.c
new file mode 100644
index 0000000..7b141d8
--- /dev/null
+++ b/arch/arm/mach-sunxi/platsmp.c
@@ -0,0 +1,124 @@
+/*
+ * SMP support for Allwinner SoCs
+ *
+ * Copyright (C) 2013 Maxime Ripard
+ *
+ * Maxime Ripard <maxime.ripard@free-electrons.com>
+ *
+ * Based on code
+ * Copyright (C) 2012-2013 Allwinner Ltd.
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/memory.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/smp.h>
+
+#include "common.h"
+
+#define CPUCFG_CPU_PWR_CLAMP_STATUS_REG(cpu) ((cpu) * 0x40 + 0x64)
+#define CPUCFG_CPU_RST_CTRL_REG(cpu) (((cpu) + 1) * 0x40)
+#define CPUCFG_CPU_CTRL_REG(cpu) (((cpu) + 1) * 0x40 + 0x04)
+#define CPUCFG_CPU_STATUS_REG(cpu) (((cpu) + 1) * 0x40 + 0x08)
+#define CPUCFG_GEN_CTRL_REG 0x184
+#define CPUCFG_PRIVATE0_REG 0x1a4
+#define CPUCFG_PRIVATE1_REG 0x1a8
+#define CPUCFG_DBG_CTL0_REG 0x1e0
+#define CPUCFG_DBG_CTL1_REG 0x1e4
+
+#define PRCM_CPU_PWROFF_REG 0x100
+#define PRCM_CPU_PWR_CLAMP_REG(cpu) (((cpu) * 4) + 0x140)
+
+static void __iomem *cpucfg_membase;
+static void __iomem *prcm_membase;
+
+static DEFINE_SPINLOCK(cpu_lock);
+
+static void __init sun6i_smp_prepare_cpus(unsigned int max_cpus)
+{
+ struct device_node *node;
+
+ node = of_find_compatible_node(NULL, NULL, "allwinner,sun6i-a31-prcm");
+ if (!node) {
+ pr_err("Missing A31 PRCM node in the device tree\n");
+ return;
+ }
+
+ prcm_membase = of_iomap(node, 0);
+ if (!prcm_membase) {
+ pr_err("Couldn't map A31 PRCM registers\n");
+ return;
+ }
+
+ node = of_find_compatible_node(NULL, NULL,
+ "allwinner,sun6i-a31-cpuconfig");
+ if (!node) {
+ pr_err("Missing A31 CPU config node in the device tree\n");
+ return;
+ }
+
+ cpucfg_membase = of_iomap(node, 0);
+ if (!cpucfg_membase)
+ pr_err("Couldn't map A31 CPU config registers\n");
+
+}
+
+static int sun6i_smp_boot_secondary(unsigned int cpu,
+ struct task_struct *idle)
+{
+ u32 reg;
+ int i;
+
+ if (!(prcm_membase && cpucfg_membase))
+ return -EFAULT;
+
+ spin_lock(&cpu_lock);
+
+ /* Set CPU boot address */
+ writel(virt_to_phys(sun6i_secondary_startup),
+ cpucfg_membase + CPUCFG_PRIVATE0_REG);
+
+ /* Assert the CPU core in reset */
+ writel(0, cpucfg_membase + CPUCFG_CPU_RST_CTRL_REG(cpu));
+
+ /* Assert the L1 cache in reset */
+ reg = readl(cpucfg_membase + CPUCFG_GEN_CTRL_REG);
+ writel(reg & ~BIT(cpu), cpucfg_membase + CPUCFG_GEN_CTRL_REG);
+
+ /* Disable external debug access */
+ reg = readl(cpucfg_membase + CPUCFG_DBG_CTL1_REG);
+ writel(reg & ~BIT(cpu), cpucfg_membase + CPUCFG_DBG_CTL1_REG);
+
+ /* Power up the CPU */
+ for (i = 0; i <= 8; i++)
+ writel(0xff >> i, prcm_membase + PRCM_CPU_PWR_CLAMP_REG(cpu));
+ mdelay(10);
+
+ /* Clear CPU power-off gating */
+ reg = readl(prcm_membase + PRCM_CPU_PWROFF_REG);
+ writel(reg & ~BIT(cpu), prcm_membase + PRCM_CPU_PWROFF_REG);
+ mdelay(1);
+
+ /* Deassert the CPU core reset */
+ writel(3, cpucfg_membase + CPUCFG_CPU_RST_CTRL_REG(cpu));
+
+ /* Enable back the external debug accesses */
+ reg = readl(cpucfg_membase + CPUCFG_DBG_CTL1_REG);
+ writel(reg | BIT(cpu), cpucfg_membase + CPUCFG_DBG_CTL1_REG);
+
+ spin_unlock(&cpu_lock);
+
+ return 0;
+}
+
+struct smp_operations sun6i_smp_ops __initdata = {
+ .smp_prepare_cpus = sun6i_smp_prepare_cpus,
+ .smp_boot_secondary = sun6i_smp_boot_secondary,
+};
diff --git a/arch/arm/mach-sunxi/sunxi.c b/arch/arm/mach-sunxi/sunxi.c
index 594ac48..aeea6ce 100644
--- a/arch/arm/mach-sunxi/sunxi.c
+++ b/arch/arm/mach-sunxi/sunxi.c
@@ -25,6 +25,8 @@
#include <asm/mach/map.h>
#include <asm/system_misc.h>
+#include "common.h"
+
#define SUN4I_WATCHDOG_CTRL_REG 0x00
#define SUN4I_WATCHDOG_CTRL_RESTART BIT(0)
#define SUN4I_WATCHDOG_MODE_REG 0x04
@@ -147,6 +149,7 @@ static void __init sun6i_timer_init(void)
.init_time = sun6i_timer_init,
.dt_compat = sun6i_board_dt_compat,
.restart = sun6i_restart,
+ .smp = smp_ops(sun6i_smp_ops),
MACHINE_END
static const char * const sun7i_board_dt_compat[] = {
--
1.8.5.1
|
