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7d30e8b3 | 1 | /* linux/arch/arm/mach-exynos4/platsmp.c |
2b12b5c4 | 2 | * |
7d30e8b3 KK |
3 | * Copyright (c) 2010-2011 Samsung Electronics Co., Ltd. |
4 | * http://www.samsung.com | |
2b12b5c4 CY |
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> | |
0f7b332f | 25 | #include <asm/hardware/gic.h> |
eb50439b | 26 | #include <asm/smp_plat.h> |
2b12b5c4 | 27 | #include <asm/smp_scu.h> |
2b12b5c4 CY |
28 | |
29 | #include <mach/hardware.h> | |
30 | #include <mach/regs-clock.h> | |
911c29b0 | 31 | #include <mach/regs-pmu.h> |
2b12b5c4 | 32 | |
56b20922 KK |
33 | #include <plat/cpu.h> |
34 | ||
06853ae4 MZ |
35 | #include "common.h" |
36 | ||
7d30e8b3 | 37 | extern void exynos4_secondary_startup(void); |
2b12b5c4 | 38 | |
56b20922 KK |
39 | #define CPU1_BOOT_REG (samsung_rev() == EXYNOS4210_REV_1_1 ? \ |
40 | S5P_INFORM5 : S5P_VA_SYSRAM) | |
911c29b0 | 41 | |
3705ff6d RK |
42 | /* |
43 | * Write pen_release in a way that is guaranteed to be visible to all | |
44 | * observers, irrespective of whether they're taking part in coherency | |
45 | * or not. This is necessary for the hotplug code to work reliably. | |
46 | */ | |
47 | static void write_pen_release(int val) | |
48 | { | |
49 | pen_release = val; | |
50 | smp_wmb(); | |
51 | __cpuc_flush_dcache_area((void *)&pen_release, sizeof(pen_release)); | |
52 | outer_clean_range(__pa(&pen_release), __pa(&pen_release + 1)); | |
53 | } | |
54 | ||
2b12b5c4 CY |
55 | static void __iomem *scu_base_addr(void) |
56 | { | |
57 | return (void __iomem *)(S5P_VA_SCU); | |
58 | } | |
59 | ||
60 | static DEFINE_SPINLOCK(boot_lock); | |
61 | ||
06853ae4 | 62 | static void __cpuinit exynos_secondary_init(unsigned int cpu) |
2b12b5c4 | 63 | { |
2b12b5c4 CY |
64 | /* |
65 | * if any interrupts are already enabled for the primary | |
66 | * core (e.g. timer irq), then they will not have been enabled | |
67 | * for us: do so | |
68 | */ | |
db0d4db2 | 69 | gic_secondary_init(0); |
2b12b5c4 CY |
70 | |
71 | /* | |
72 | * let the primary processor know we're out of the | |
73 | * pen, then head off into the C entry point | |
74 | */ | |
3705ff6d | 75 | write_pen_release(-1); |
2b12b5c4 CY |
76 | |
77 | /* | |
78 | * Synchronise with the boot thread. | |
79 | */ | |
80 | spin_lock(&boot_lock); | |
81 | spin_unlock(&boot_lock); | |
82 | } | |
83 | ||
06853ae4 | 84 | static int __cpuinit exynos_boot_secondary(unsigned int cpu, struct task_struct *idle) |
2b12b5c4 CY |
85 | { |
86 | unsigned long timeout; | |
87 | ||
88 | /* | |
89 | * Set synchronisation state between this boot processor | |
90 | * and the secondary one | |
91 | */ | |
92 | spin_lock(&boot_lock); | |
93 | ||
94 | /* | |
95 | * The secondary processor is waiting to be released from | |
96 | * the holding pen - release it, then wait for it to flag | |
97 | * that it has been released by resetting pen_release. | |
98 | * | |
99 | * Note that "pen_release" is the hardware CPU ID, whereas | |
100 | * "cpu" is Linux's internal ID. | |
101 | */ | |
2f41c36b | 102 | write_pen_release(cpu_logical_map(cpu)); |
2b12b5c4 | 103 | |
911c29b0 JM |
104 | if (!(__raw_readl(S5P_ARM_CORE1_STATUS) & S5P_CORE_LOCAL_PWR_EN)) { |
105 | __raw_writel(S5P_CORE_LOCAL_PWR_EN, | |
106 | S5P_ARM_CORE1_CONFIGURATION); | |
107 | ||
108 | timeout = 10; | |
109 | ||
110 | /* wait max 10 ms until cpu1 is on */ | |
111 | while ((__raw_readl(S5P_ARM_CORE1_STATUS) | |
112 | & S5P_CORE_LOCAL_PWR_EN) != S5P_CORE_LOCAL_PWR_EN) { | |
113 | if (timeout-- == 0) | |
114 | break; | |
115 | ||
116 | mdelay(1); | |
117 | } | |
118 | ||
119 | if (timeout == 0) { | |
120 | printk(KERN_ERR "cpu1 power enable failed"); | |
121 | spin_unlock(&boot_lock); | |
122 | return -ETIMEDOUT; | |
123 | } | |
124 | } | |
2b12b5c4 CY |
125 | /* |
126 | * Send the secondary CPU a soft interrupt, thereby causing | |
127 | * the boot monitor to read the system wide flags register, | |
128 | * and branch to the address found there. | |
129 | */ | |
2b12b5c4 CY |
130 | |
131 | timeout = jiffies + (1 * HZ); | |
132 | while (time_before(jiffies, timeout)) { | |
133 | smp_rmb(); | |
911c29b0 | 134 | |
f7597c02 | 135 | __raw_writel(virt_to_phys(exynos4_secondary_startup), |
911c29b0 | 136 | CPU1_BOOT_REG); |
5b7cc3df | 137 | gic_raise_softirq(cpumask_of(cpu), 0); |
911c29b0 | 138 | |
2b12b5c4 CY |
139 | if (pen_release == -1) |
140 | break; | |
141 | ||
142 | udelay(10); | |
143 | } | |
144 | ||
145 | /* | |
146 | * now the secondary core is starting up let it run its | |
147 | * calibrations, then wait for it to finish | |
148 | */ | |
149 | spin_unlock(&boot_lock); | |
150 | ||
151 | return pen_release != -1 ? -ENOSYS : 0; | |
152 | } | |
153 | ||
154 | /* | |
155 | * Initialise the CPU possible map early - this describes the CPUs | |
156 | * which may be present or become present in the system. | |
157 | */ | |
158 | ||
06853ae4 | 159 | static void __init exynos_smp_init_cpus(void) |
2b12b5c4 CY |
160 | { |
161 | void __iomem *scu_base = scu_base_addr(); | |
162 | unsigned int i, ncores; | |
163 | ||
e9bba615 KK |
164 | if (soc_is_exynos5250()) |
165 | ncores = 2; | |
166 | else | |
167 | ncores = scu_base ? scu_get_core_count(scu_base) : 1; | |
2b12b5c4 CY |
168 | |
169 | /* sanity check */ | |
a06f916b RK |
170 | if (ncores > nr_cpu_ids) { |
171 | pr_warn("SMP: %u cores greater than maximum (%u), clipping\n", | |
172 | ncores, nr_cpu_ids); | |
173 | ncores = nr_cpu_ids; | |
2b12b5c4 CY |
174 | } |
175 | ||
176 | for (i = 0; i < ncores; i++) | |
177 | set_cpu_possible(i, true); | |
0f7b332f RK |
178 | |
179 | set_smp_cross_call(gic_raise_softirq); | |
2b12b5c4 CY |
180 | } |
181 | ||
06853ae4 | 182 | static void __init exynos_smp_prepare_cpus(unsigned int max_cpus) |
2b12b5c4 | 183 | { |
e9bba615 KK |
184 | if (!soc_is_exynos5250()) |
185 | scu_enable(scu_base_addr()); | |
05c74a6c | 186 | |
2b12b5c4 | 187 | /* |
05c74a6c RK |
188 | * Write the address of secondary startup into the |
189 | * system-wide flags register. The boot monitor waits | |
190 | * until it receives a soft interrupt, and then the | |
191 | * secondary CPU branches to this address. | |
2b12b5c4 | 192 | */ |
f7597c02 | 193 | __raw_writel(virt_to_phys(exynos4_secondary_startup), |
56b20922 | 194 | CPU1_BOOT_REG); |
2b12b5c4 | 195 | } |
06853ae4 MZ |
196 | |
197 | struct smp_operations exynos_smp_ops __initdata = { | |
198 | .smp_init_cpus = exynos_smp_init_cpus, | |
199 | .smp_prepare_cpus = exynos_smp_prepare_cpus, | |
200 | .smp_secondary_init = exynos_secondary_init, | |
201 | .smp_boot_secondary = exynos_boot_secondary, | |
202 | #ifdef CONFIG_HOTPLUG_CPU | |
203 | .cpu_die = exynos_cpu_die, | |
204 | #endif | |
205 | }; |