diff options
author | Kukjin Kim <kgene.kim@samsung.com> | 2010-08-06 08:31:49 -0400 |
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committer | Kukjin Kim <kgene.kim@samsung.com> | 2010-08-06 08:31:49 -0400 |
commit | 6b8eda04ffdc24b68d379a32358f4f09a425a380 (patch) | |
tree | 4343c4b891322dfebfb7061ae10c488c1747bbbb /arch/arm/mach-s5pv310/platsmp.c | |
parent | a639718b83867b3d4af3bf18c7e6a23d92b35f7a (diff) | |
parent | 516607d64dd1efe77147e2856188d4318ac7fcce (diff) |
Merge branch 'next-s5pv310' into for-next
Diffstat (limited to 'arch/arm/mach-s5pv310/platsmp.c')
-rw-r--r-- | arch/arm/mach-s5pv310/platsmp.c | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/arch/arm/mach-s5pv310/platsmp.c b/arch/arm/mach-s5pv310/platsmp.c new file mode 100644 index 000000000000..fe9469abd006 --- /dev/null +++ b/arch/arm/mach-s5pv310/platsmp.c | |||
@@ -0,0 +1,192 @@ | |||
1 | /* linux/arch/arm/mach-s5pv310/platsmp.c | ||
2 | * | ||
3 | * Copyright (c) 2010 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/localtimer.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 | |||
32 | extern void s5pv310_secondary_startup(void); | ||
33 | |||
34 | /* | ||
35 | * control for which core is the next to come out of the secondary | ||
36 | * boot "holding pen" | ||
37 | */ | ||
38 | |||
39 | volatile int __cpuinitdata pen_release = -1; | ||
40 | |||
41 | static void __iomem *scu_base_addr(void) | ||
42 | { | ||
43 | return (void __iomem *)(S5P_VA_SCU); | ||
44 | } | ||
45 | |||
46 | static DEFINE_SPINLOCK(boot_lock); | ||
47 | |||
48 | void __cpuinit platform_secondary_init(unsigned int cpu) | ||
49 | { | ||
50 | trace_hardirqs_off(); | ||
51 | |||
52 | /* | ||
53 | * if any interrupts are already enabled for the primary | ||
54 | * core (e.g. timer irq), then they will not have been enabled | ||
55 | * for us: do so | ||
56 | */ | ||
57 | gic_cpu_init(0, gic_cpu_base_addr); | ||
58 | |||
59 | /* | ||
60 | * let the primary processor know we're out of the | ||
61 | * pen, then head off into the C entry point | ||
62 | */ | ||
63 | pen_release = -1; | ||
64 | smp_wmb(); | ||
65 | |||
66 | /* | ||
67 | * Synchronise with the boot thread. | ||
68 | */ | ||
69 | spin_lock(&boot_lock); | ||
70 | spin_unlock(&boot_lock); | ||
71 | } | ||
72 | |||
73 | int __cpuinit boot_secondary(unsigned int cpu, struct task_struct *idle) | ||
74 | { | ||
75 | unsigned long timeout; | ||
76 | |||
77 | /* | ||
78 | * Set synchronisation state between this boot processor | ||
79 | * and the secondary one | ||
80 | */ | ||
81 | spin_lock(&boot_lock); | ||
82 | |||
83 | /* | ||
84 | * The secondary processor is waiting to be released from | ||
85 | * the holding pen - release it, then wait for it to flag | ||
86 | * that it has been released by resetting pen_release. | ||
87 | * | ||
88 | * Note that "pen_release" is the hardware CPU ID, whereas | ||
89 | * "cpu" is Linux's internal ID. | ||
90 | */ | ||
91 | pen_release = cpu; | ||
92 | __cpuc_flush_dcache_area((void *)&pen_release, sizeof(pen_release)); | ||
93 | outer_clean_range(__pa(&pen_release), __pa(&pen_release + 1)); | ||
94 | |||
95 | /* | ||
96 | * Send the secondary CPU a soft interrupt, thereby causing | ||
97 | * the boot monitor to read the system wide flags register, | ||
98 | * and branch to the address found there. | ||
99 | */ | ||
100 | smp_cross_call(cpumask_of(cpu)); | ||
101 | |||
102 | timeout = jiffies + (1 * HZ); | ||
103 | while (time_before(jiffies, timeout)) { | ||
104 | smp_rmb(); | ||
105 | if (pen_release == -1) | ||
106 | break; | ||
107 | |||
108 | udelay(10); | ||
109 | } | ||
110 | |||
111 | /* | ||
112 | * now the secondary core is starting up let it run its | ||
113 | * calibrations, then wait for it to finish | ||
114 | */ | ||
115 | spin_unlock(&boot_lock); | ||
116 | |||
117 | return pen_release != -1 ? -ENOSYS : 0; | ||
118 | } | ||
119 | |||
120 | /* | ||
121 | * Initialise the CPU possible map early - this describes the CPUs | ||
122 | * which may be present or become present in the system. | ||
123 | */ | ||
124 | |||
125 | void __init smp_init_cpus(void) | ||
126 | { | ||
127 | void __iomem *scu_base = scu_base_addr(); | ||
128 | unsigned int i, ncores; | ||
129 | |||
130 | ncores = scu_base ? scu_get_core_count(scu_base) : 1; | ||
131 | |||
132 | /* sanity check */ | ||
133 | if (ncores == 0) { | ||
134 | printk(KERN_ERR | ||
135 | "S5PV310: strange CM count of 0? Default to 1\n"); | ||
136 | |||
137 | ncores = 1; | ||
138 | } | ||
139 | |||
140 | if (ncores > NR_CPUS) { | ||
141 | printk(KERN_WARNING | ||
142 | "S5PV310: no. of cores (%d) greater than configured " | ||
143 | "maximum of %d - clipping\n", | ||
144 | ncores, NR_CPUS); | ||
145 | ncores = NR_CPUS; | ||
146 | } | ||
147 | |||
148 | for (i = 0; i < ncores; i++) | ||
149 | set_cpu_possible(i, true); | ||
150 | } | ||
151 | |||
152 | void __init smp_prepare_cpus(unsigned int max_cpus) | ||
153 | { | ||
154 | unsigned int ncores = num_possible_cpus(); | ||
155 | unsigned int cpu = smp_processor_id(); | ||
156 | int i; | ||
157 | |||
158 | smp_store_cpu_info(cpu); | ||
159 | |||
160 | /* are we trying to boot more cores than exist? */ | ||
161 | if (max_cpus > ncores) | ||
162 | max_cpus = ncores; | ||
163 | |||
164 | /* | ||
165 | * Initialise the present map, which describes the set of CPUs | ||
166 | * actually populated at the present time. | ||
167 | */ | ||
168 | for (i = 0; i < max_cpus; i++) | ||
169 | set_cpu_present(i, true); | ||
170 | |||
171 | /* | ||
172 | * Initialise the SCU if there are more than one CPU and let | ||
173 | * them know where to start. | ||
174 | */ | ||
175 | if (max_cpus > 1) { | ||
176 | /* | ||
177 | * Enable the local timer or broadcast device for the | ||
178 | * boot CPU, but only if we have more than one CPU. | ||
179 | */ | ||
180 | percpu_timer_setup(); | ||
181 | |||
182 | scu_enable(scu_base_addr()); | ||
183 | |||
184 | /* | ||
185 | * Write the address of secondary startup into the | ||
186 | * system-wide flags register. The boot monitor waits | ||
187 | * until it receives a soft interrupt, and then the | ||
188 | * secondary CPU branches to this address. | ||
189 | */ | ||
190 | __raw_writel(BSYM(virt_to_phys(s5pv310_secondary_startup)), S5P_INFORM0); | ||
191 | } | ||
192 | } | ||