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authorJonathan Herman <hermanjl@cs.unc.edu>2013-01-22 10:38:37 -0500
committerJonathan Herman <hermanjl@cs.unc.edu>2013-01-22 10:38:37 -0500
commitfcc9d2e5a6c89d22b8b773a64fb4ad21ac318446 (patch)
treea57612d1888735a2ec7972891b68c1ac5ec8faea /arch/arm/mach-exynos4/platsmp.c
parent8dea78da5cee153b8af9c07a2745f6c55057fe12 (diff)
Added missing tegra files.HEADmaster
Diffstat (limited to 'arch/arm/mach-exynos4/platsmp.c')
-rw-r--r--arch/arm/mach-exynos4/platsmp.c220
1 files changed, 220 insertions, 0 deletions
diff --git a/arch/arm/mach-exynos4/platsmp.c b/arch/arm/mach-exynos4/platsmp.c
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1/* linux/arch/arm/mach-exynos4/platsmp.c
2 *
3 * Copyright (c) 2010-2011 Samsung Electronics Co., Ltd.
4 * http://www.samsung.com
5 *
6 * Cloned from linux/arch/arm/mach-vexpress/platsmp.c
7 *
8 * Copyright (C) 2002 ARM Ltd.
9 * All Rights Reserved
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License version 2 as
13 * published by the Free Software Foundation.
14*/
15
16#include <linux/init.h>
17#include <linux/errno.h>
18#include <linux/delay.h>
19#include <linux/device.h>
20#include <linux/jiffies.h>
21#include <linux/smp.h>
22#include <linux/io.h>
23
24#include <asm/cacheflush.h>
25#include <asm/hardware/gic.h>
26#include <asm/smp_scu.h>
27#include <asm/unified.h>
28
29#include <mach/hardware.h>
30#include <mach/regs-clock.h>
31#include <mach/regs-pmu.h>
32
33extern void exynos4_secondary_startup(void);
34
35#define CPU1_BOOT_REG S5P_VA_SYSRAM
36
37/*
38 * control for which core is the next to come out of the secondary
39 * boot "holding pen"
40 */
41
42volatile int __cpuinitdata pen_release = -1;
43
44/*
45 * Write pen_release in a way that is guaranteed to be visible to all
46 * observers, irrespective of whether they're taking part in coherency
47 * or not. This is necessary for the hotplug code to work reliably.
48 */
49static void write_pen_release(int val)
50{
51 pen_release = val;
52 smp_wmb();
53 __cpuc_flush_dcache_area((void *)&pen_release, sizeof(pen_release));
54 outer_clean_range(__pa(&pen_release), __pa(&pen_release + 1));
55}
56
57static void __iomem *scu_base_addr(void)
58{
59 return (void __iomem *)(S5P_VA_SCU);
60}
61
62static DEFINE_SPINLOCK(boot_lock);
63
64static void __cpuinit exynos4_gic_secondary_init(void)
65{
66 void __iomem *dist_base = S5P_VA_GIC_DIST +
67 (EXYNOS4_GIC_BANK_OFFSET * smp_processor_id());
68 void __iomem *cpu_base = S5P_VA_GIC_CPU +
69 (EXYNOS4_GIC_BANK_OFFSET * smp_processor_id());
70 int i;
71
72 /*
73 * Deal with the banked PPI and SGI interrupts - disable all
74 * PPI interrupts, ensure all SGI interrupts are enabled.
75 */
76 __raw_writel(0xffff0000, dist_base + GIC_DIST_ENABLE_CLEAR);
77 __raw_writel(0x0000ffff, dist_base + GIC_DIST_ENABLE_SET);
78
79 /*
80 * Set priority on PPI and SGI interrupts
81 */
82 for (i = 0; i < 32; i += 4)
83 __raw_writel(0xa0a0a0a0, dist_base + GIC_DIST_PRI + i * 4 / 4);
84
85 __raw_writel(0xf0, cpu_base + GIC_CPU_PRIMASK);
86 __raw_writel(1, cpu_base + GIC_CPU_CTRL);
87}
88
89void __cpuinit platform_secondary_init(unsigned int cpu)
90{
91 /*
92 * if any interrupts are already enabled for the primary
93 * core (e.g. timer irq), then they will not have been enabled
94 * for us: do so
95 */
96 exynos4_gic_secondary_init();
97
98 /*
99 * let the primary processor know we're out of the
100 * pen, then head off into the C entry point
101 */
102 write_pen_release(-1);
103
104 /*
105 * Synchronise with the boot thread.
106 */
107 spin_lock(&boot_lock);
108 spin_unlock(&boot_lock);
109
110 set_cpu_online(cpu, true);
111}
112
113int __cpuinit boot_secondary(unsigned int cpu, struct task_struct *idle)
114{
115 unsigned long timeout;
116
117 /*
118 * Set synchronisation state between this boot processor
119 * and the secondary one
120 */
121 spin_lock(&boot_lock);
122
123 /*
124 * The secondary processor is waiting to be released from
125 * the holding pen - release it, then wait for it to flag
126 * that it has been released by resetting pen_release.
127 *
128 * Note that "pen_release" is the hardware CPU ID, whereas
129 * "cpu" is Linux's internal ID.
130 */
131 write_pen_release(cpu);
132
133 if (!(__raw_readl(S5P_ARM_CORE1_STATUS) & S5P_CORE_LOCAL_PWR_EN)) {
134 __raw_writel(S5P_CORE_LOCAL_PWR_EN,
135 S5P_ARM_CORE1_CONFIGURATION);
136
137 timeout = 10;
138
139 /* wait max 10 ms until cpu1 is on */
140 while ((__raw_readl(S5P_ARM_CORE1_STATUS)
141 & S5P_CORE_LOCAL_PWR_EN) != S5P_CORE_LOCAL_PWR_EN) {
142 if (timeout-- == 0)
143 break;
144
145 mdelay(1);
146 }
147
148 if (timeout == 0) {
149 printk(KERN_ERR "cpu1 power enable failed");
150 spin_unlock(&boot_lock);
151 return -ETIMEDOUT;
152 }
153 }
154 /*
155 * Send the secondary CPU a soft interrupt, thereby causing
156 * the boot monitor to read the system wide flags register,
157 * and branch to the address found there.
158 */
159
160 timeout = jiffies + (1 * HZ);
161 while (time_before(jiffies, timeout)) {
162 smp_rmb();
163
164 __raw_writel(BSYM(virt_to_phys(exynos4_secondary_startup)),
165 CPU1_BOOT_REG);
166 gic_raise_softirq(cpumask_of(cpu), 1);
167
168 if (pen_release == -1)
169 break;
170
171 udelay(10);
172 }
173
174 /*
175 * now the secondary core is starting up let it run its
176 * calibrations, then wait for it to finish
177 */
178 spin_unlock(&boot_lock);
179
180 return pen_release != -1 ? -ENOSYS : 0;
181}
182
183/*
184 * Initialise the CPU possible map early - this describes the CPUs
185 * which may be present or become present in the system.
186 */
187
188void __init smp_init_cpus(void)
189{
190 void __iomem *scu_base = scu_base_addr();
191 unsigned int i, ncores;
192
193 ncores = scu_base ? scu_get_core_count(scu_base) : 1;
194
195 /* sanity check */
196 if (ncores > nr_cpu_ids) {
197 pr_warn("SMP: %u cores greater than maximum (%u), clipping\n",
198 ncores, nr_cpu_ids);
199 ncores = nr_cpu_ids;
200 }
201
202 for (i = 0; i < ncores; i++)
203 set_cpu_possible(i, true);
204
205 set_smp_cross_call(gic_raise_softirq);
206}
207
208void __init platform_smp_prepare_cpus(unsigned int max_cpus)
209{
210
211 scu_enable(scu_base_addr());
212
213 /*
214 * Write the address of secondary startup into the
215 * system-wide flags register. The boot monitor waits
216 * until it receives a soft interrupt, and then the
217 * secondary CPU branches to this address.
218 */
219 __raw_writel(BSYM(virt_to_phys(exynos4_secondary_startup)), S5P_VA_SYSRAM);
220}