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862184fe RK |
1 | /* |
2 | * linux/arch/arm/mach-realview/platsmp.c | |
3 | * | |
4 | * Copyright (C) 2002 ARM Ltd. | |
5 | * All Rights Reserved | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License version 2 as | |
9 | * published by the Free Software Foundation. | |
10 | */ | |
11 | #include <linux/init.h> | |
12 | #include <linux/errno.h> | |
13 | #include <linux/delay.h> | |
14 | #include <linux/device.h> | |
15 | #include <linux/smp.h> | |
16 | ||
17 | #include <asm/cacheflush.h> | |
a09e64fb | 18 | #include <mach/hardware.h> |
ce07d90a | 19 | #include <asm/io.h> |
7dd19e75 | 20 | #include <asm/mach-types.h> |
862184fe | 21 | |
a09e64fb RK |
22 | #include <mach/board-eb.h> |
23 | #include <mach/board-pb11mp.h> | |
24 | #include <mach/scu.h> | |
b7b0ba94 | 25 | |
862184fe RK |
26 | extern void realview_secondary_startup(void); |
27 | ||
28 | /* | |
29 | * control for which core is the next to come out of the secondary | |
30 | * boot "holding pen" | |
31 | */ | |
32 | volatile int __cpuinitdata pen_release = -1; | |
33 | ||
34 | static unsigned int __init get_core_count(void) | |
35 | { | |
36 | unsigned int ncores; | |
b7b0ba94 CM |
37 | void __iomem *scu_base = 0; |
38 | ||
39 | if (machine_is_realview_eb() && core_tile_eb11mp()) | |
40 | scu_base = __io_address(REALVIEW_EB11MP_SCU_BASE); | |
e67172f5 CM |
41 | else if (machine_is_realview_pb11mp()) |
42 | scu_base = __io_address(REALVIEW_TC11MP_SCU_BASE); | |
862184fe | 43 | |
b7b0ba94 CM |
44 | if (scu_base) { |
45 | ncores = __raw_readl(scu_base + SCU_CONFIG); | |
7dd19e75 CM |
46 | ncores = (ncores & 0x03) + 1; |
47 | } else | |
48 | ncores = 1; | |
862184fe | 49 | |
7dd19e75 | 50 | return ncores; |
862184fe RK |
51 | } |
52 | ||
b7b0ba94 CM |
53 | /* |
54 | * Setup the SCU | |
55 | */ | |
56 | static void scu_enable(void) | |
57 | { | |
58 | u32 scu_ctrl; | |
59 | void __iomem *scu_base; | |
60 | ||
61 | if (machine_is_realview_eb() && core_tile_eb11mp()) | |
62 | scu_base = __io_address(REALVIEW_EB11MP_SCU_BASE); | |
e67172f5 CM |
63 | else if (machine_is_realview_pb11mp()) |
64 | scu_base = __io_address(REALVIEW_TC11MP_SCU_BASE); | |
b7b0ba94 CM |
65 | else |
66 | BUG(); | |
67 | ||
68 | scu_ctrl = __raw_readl(scu_base + SCU_CTRL); | |
69 | scu_ctrl |= 1; | |
70 | __raw_writel(scu_ctrl, scu_base + SCU_CTRL); | |
71 | } | |
72 | ||
862184fe RK |
73 | static DEFINE_SPINLOCK(boot_lock); |
74 | ||
75 | void __cpuinit platform_secondary_init(unsigned int cpu) | |
76 | { | |
08383ef2 CM |
77 | trace_hardirqs_off(); |
78 | ||
862184fe RK |
79 | /* |
80 | * the primary core may have used a "cross call" soft interrupt | |
81 | * to get this processor out of WFI in the BootMonitor - make | |
82 | * sure that we are no longer being sent this soft interrupt | |
83 | */ | |
84 | smp_cross_call_done(cpumask_of_cpu(cpu)); | |
85 | ||
86 | /* | |
87 | * if any interrupts are already enabled for the primary | |
88 | * core (e.g. timer irq), then they will not have been enabled | |
89 | * for us: do so | |
90 | */ | |
e67172f5 CM |
91 | if (machine_is_realview_eb() && core_tile_eb11mp()) |
92 | gic_cpu_init(0, __io_address(REALVIEW_EB11MP_GIC_CPU_BASE)); | |
93 | else if (machine_is_realview_pb11mp()) | |
94 | gic_cpu_init(0, __io_address(REALVIEW_TC11MP_GIC_CPU_BASE)); | |
862184fe RK |
95 | |
96 | /* | |
97 | * let the primary processor know we're out of the | |
98 | * pen, then head off into the C entry point | |
99 | */ | |
100 | pen_release = -1; | |
0e0ba769 | 101 | smp_wmb(); |
862184fe RK |
102 | |
103 | /* | |
104 | * Synchronise with the boot thread. | |
105 | */ | |
106 | spin_lock(&boot_lock); | |
107 | spin_unlock(&boot_lock); | |
108 | } | |
109 | ||
110 | int __cpuinit boot_secondary(unsigned int cpu, struct task_struct *idle) | |
111 | { | |
112 | unsigned long timeout; | |
113 | ||
114 | /* | |
115 | * set synchronisation state between this boot processor | |
116 | * and the secondary one | |
117 | */ | |
118 | spin_lock(&boot_lock); | |
119 | ||
120 | /* | |
121 | * The secondary processor is waiting to be released from | |
122 | * the holding pen - release it, then wait for it to flag | |
123 | * that it has been released by resetting pen_release. | |
124 | * | |
125 | * Note that "pen_release" is the hardware CPU ID, whereas | |
126 | * "cpu" is Linux's internal ID. | |
127 | */ | |
128 | pen_release = cpu; | |
129 | flush_cache_all(); | |
130 | ||
131 | /* | |
132 | * XXX | |
133 | * | |
134 | * This is a later addition to the booting protocol: the | |
135 | * bootMonitor now puts secondary cores into WFI, so | |
136 | * poke_milo() no longer gets the cores moving; we need | |
137 | * to send a soft interrupt to wake the secondary core. | |
138 | * Use smp_cross_call() for this, since there's little | |
139 | * point duplicating the code here | |
140 | */ | |
141 | smp_cross_call(cpumask_of_cpu(cpu)); | |
142 | ||
143 | timeout = jiffies + (1 * HZ); | |
144 | while (time_before(jiffies, timeout)) { | |
0e0ba769 | 145 | smp_rmb(); |
862184fe RK |
146 | if (pen_release == -1) |
147 | break; | |
148 | ||
149 | udelay(10); | |
150 | } | |
151 | ||
152 | /* | |
153 | * now the secondary core is starting up let it run its | |
154 | * calibrations, then wait for it to finish | |
155 | */ | |
156 | spin_unlock(&boot_lock); | |
157 | ||
158 | return pen_release != -1 ? -ENOSYS : 0; | |
159 | } | |
160 | ||
161 | static void __init poke_milo(void) | |
162 | { | |
163 | extern void secondary_startup(void); | |
164 | ||
165 | /* nobody is to be released from the pen yet */ | |
166 | pen_release = -1; | |
167 | ||
168 | /* | |
169 | * write the address of secondary startup into the system-wide | |
170 | * flags register, then clear the bottom two bits, which is what | |
171 | * BootMonitor is waiting for | |
172 | */ | |
173 | #if 1 | |
174 | #define REALVIEW_SYS_FLAGSS_OFFSET 0x30 | |
175 | __raw_writel(virt_to_phys(realview_secondary_startup), | |
5d43045b RK |
176 | __io_address(REALVIEW_SYS_BASE) + |
177 | REALVIEW_SYS_FLAGSS_OFFSET); | |
862184fe RK |
178 | #define REALVIEW_SYS_FLAGSC_OFFSET 0x34 |
179 | __raw_writel(3, | |
5d43045b RK |
180 | __io_address(REALVIEW_SYS_BASE) + |
181 | REALVIEW_SYS_FLAGSC_OFFSET); | |
862184fe RK |
182 | #endif |
183 | ||
184 | mb(); | |
185 | } | |
186 | ||
7bbb7940 RK |
187 | /* |
188 | * Initialise the CPU possible map early - this describes the CPUs | |
189 | * which may be present or become present in the system. | |
190 | */ | |
191 | void __init smp_init_cpus(void) | |
192 | { | |
193 | unsigned int i, ncores = get_core_count(); | |
194 | ||
195 | for (i = 0; i < ncores; i++) | |
196 | cpu_set(i, cpu_possible_map); | |
197 | } | |
198 | ||
862184fe RK |
199 | void __init smp_prepare_cpus(unsigned int max_cpus) |
200 | { | |
201 | unsigned int ncores = get_core_count(); | |
202 | unsigned int cpu = smp_processor_id(); | |
203 | int i; | |
204 | ||
205 | /* sanity check */ | |
206 | if (ncores == 0) { | |
207 | printk(KERN_ERR | |
208 | "Realview: strange CM count of 0? Default to 1\n"); | |
209 | ||
210 | ncores = 1; | |
211 | } | |
212 | ||
213 | if (ncores > NR_CPUS) { | |
214 | printk(KERN_WARNING | |
215 | "Realview: no. of cores (%d) greater than configured " | |
216 | "maximum of %d - clipping\n", | |
217 | ncores, NR_CPUS); | |
218 | ncores = NR_CPUS; | |
219 | } | |
220 | ||
221 | smp_store_cpu_info(cpu); | |
222 | ||
223 | /* | |
224 | * are we trying to boot more cores than exist? | |
225 | */ | |
226 | if (max_cpus > ncores) | |
227 | max_cpus = ncores; | |
228 | ||
a8655e83 | 229 | #ifdef CONFIG_LOCAL_TIMERS |
2a98beb6 | 230 | /* |
a8655e83 CM |
231 | * Enable the local timer for primary CPU. If the device is |
232 | * dummy (!CONFIG_LOCAL_TIMERS), it was already registers in | |
233 | * realview_timer_init | |
2a98beb6 | 234 | */ |
e67172f5 CM |
235 | if ((machine_is_realview_eb() && core_tile_eb11mp()) || |
236 | machine_is_realview_pb11mp()) | |
7dd19e75 | 237 | local_timer_setup(cpu); |
a8655e83 | 238 | #endif |
2a98beb6 | 239 | |
862184fe | 240 | /* |
7bbb7940 RK |
241 | * Initialise the present map, which describes the set of CPUs |
242 | * actually populated at the present time. | |
862184fe | 243 | */ |
7bbb7940 | 244 | for (i = 0; i < max_cpus; i++) |
862184fe | 245 | cpu_set(i, cpu_present_map); |
862184fe RK |
246 | |
247 | /* | |
b7b0ba94 CM |
248 | * Initialise the SCU if there are more than one CPU and let |
249 | * them know where to start. Note that, on modern versions of | |
250 | * MILO, the "poke" doesn't actually do anything until each | |
251 | * individual core is sent a soft interrupt to get it out of | |
252 | * WFI | |
862184fe | 253 | */ |
b7b0ba94 CM |
254 | if (max_cpus > 1) { |
255 | scu_enable(); | |
862184fe | 256 | poke_milo(); |
b7b0ba94 | 257 | } |
862184fe | 258 | } |