blob: 009265818d55752aa401ad8bde837d59a6b89ea5 [file] [log] [blame]
Russell King862184f2005-11-07 21:05:42 +00001/*
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>
Russell King934848d2009-01-08 09:58:51 +000015#include <linux/jiffies.h>
Russell King862184f2005-11-07 21:05:42 +000016#include <linux/smp.h>
Russell Kingfced80c2008-09-06 12:10:45 +010017#include <linux/io.h>
Russell King862184f2005-11-07 21:05:42 +000018
19#include <asm/cacheflush.h>
Russell Kinga09e64f2008-08-05 16:14:15 +010020#include <mach/hardware.h>
Catalin Marinas7dd19e72008-02-04 17:39:00 +010021#include <asm/mach-types.h>
Russell Kingbc282482009-05-17 18:58:34 +010022#include <asm/localtimer.h>
Catalin Marinasdff2ab12009-07-24 12:33:00 +010023#include <asm/unified.h>
Russell King862184f2005-11-07 21:05:42 +000024
Russell Kinga09e64f2008-08-05 16:14:15 +010025#include <mach/board-eb.h>
26#include <mach/board-pb11mp.h>
Colin Tuckley1b504bb2009-05-30 13:56:12 +010027#include <mach/board-pbx.h>
Russell King49613d42009-05-16 11:41:53 +010028#include <asm/smp_scu.h>
Catalin Marinasb7b0ba92008-04-18 22:43:08 +010029
Catalin Marinas1bbdf632008-12-01 14:54:58 +000030#include "core.h"
31
Russell King862184f2005-11-07 21:05:42 +000032extern void realview_secondary_startup(void);
33
34/*
35 * control for which core is the next to come out of the secondary
36 * boot "holding pen"
37 */
38volatile int __cpuinitdata pen_release = -1;
39
Catalin Marinas1bbdf632008-12-01 14:54:58 +000040static void __iomem *scu_base_addr(void)
41{
42 if (machine_is_realview_eb_mp())
43 return __io_address(REALVIEW_EB11MP_SCU_BASE);
44 else if (machine_is_realview_pb11mp())
45 return __io_address(REALVIEW_TC11MP_SCU_BASE);
Colin Tuckley1b504bb2009-05-30 13:56:12 +010046 else if (machine_is_realview_pbx() &&
47 (core_tile_pbx11mp() || core_tile_pbxa9mp()))
48 return __io_address(REALVIEW_PBX_TILE_SCU_BASE);
Catalin Marinas1bbdf632008-12-01 14:54:58 +000049 else
50 return (void __iomem *)0;
51}
52
Russell Kinga8cbcd92009-05-16 11:51:14 +010053static inline unsigned int get_core_count(void)
Russell King862184f2005-11-07 21:05:42 +000054{
Catalin Marinas1bbdf632008-12-01 14:54:58 +000055 void __iomem *scu_base = scu_base_addr();
Russell Kinga8cbcd92009-05-16 11:51:14 +010056 if (scu_base)
57 return scu_get_core_count(scu_base);
58 return 1;
Catalin Marinasb7b0ba92008-04-18 22:43:08 +010059}
60
Russell King862184f2005-11-07 21:05:42 +000061static DEFINE_SPINLOCK(boot_lock);
62
63void __cpuinit platform_secondary_init(unsigned int cpu)
64{
Catalin Marinas08383ef2008-06-27 15:15:12 +010065 trace_hardirqs_off();
66
Russell King862184f2005-11-07 21:05:42 +000067 /*
Russell King862184f2005-11-07 21:05:42 +000068 * if any interrupts are already enabled for the primary
69 * core (e.g. timer irq), then they will not have been enabled
70 * for us: do so
71 */
Catalin Marinas1bbdf632008-12-01 14:54:58 +000072 gic_cpu_init(0, gic_cpu_base_addr);
Russell King862184f2005-11-07 21:05:42 +000073
74 /*
75 * let the primary processor know we're out of the
76 * pen, then head off into the C entry point
77 */
78 pen_release = -1;
Catalin Marinas0e0ba762007-02-15 19:05:29 +010079 smp_wmb();
Russell King862184f2005-11-07 21:05:42 +000080
81 /*
82 * Synchronise with the boot thread.
83 */
84 spin_lock(&boot_lock);
85 spin_unlock(&boot_lock);
86}
87
88int __cpuinit boot_secondary(unsigned int cpu, struct task_struct *idle)
89{
90 unsigned long timeout;
91
92 /*
93 * set synchronisation state between this boot processor
94 * and the secondary one
95 */
96 spin_lock(&boot_lock);
97
98 /*
99 * The secondary processor is waiting to be released from
100 * the holding pen - release it, then wait for it to flag
101 * that it has been released by resetting pen_release.
102 *
103 * Note that "pen_release" is the hardware CPU ID, whereas
104 * "cpu" is Linux's internal ID.
105 */
106 pen_release = cpu;
107 flush_cache_all();
108
109 /*
110 * XXX
111 *
112 * This is a later addition to the booting protocol: the
113 * bootMonitor now puts secondary cores into WFI, so
114 * poke_milo() no longer gets the cores moving; we need
115 * to send a soft interrupt to wake the secondary core.
116 * Use smp_cross_call() for this, since there's little
117 * point duplicating the code here
118 */
Russell King82668102009-05-17 16:20:18 +0100119 smp_cross_call(cpumask_of(cpu));
Russell King862184f2005-11-07 21:05:42 +0000120
121 timeout = jiffies + (1 * HZ);
122 while (time_before(jiffies, timeout)) {
Catalin Marinas0e0ba762007-02-15 19:05:29 +0100123 smp_rmb();
Russell King862184f2005-11-07 21:05:42 +0000124 if (pen_release == -1)
125 break;
126
127 udelay(10);
128 }
129
130 /*
131 * now the secondary core is starting up let it run its
132 * calibrations, then wait for it to finish
133 */
134 spin_unlock(&boot_lock);
135
136 return pen_release != -1 ? -ENOSYS : 0;
137}
138
139static void __init poke_milo(void)
140{
Russell King862184f2005-11-07 21:05:42 +0000141 /* nobody is to be released from the pen yet */
142 pen_release = -1;
143
144 /*
Catalin Marinasdff2ab12009-07-24 12:33:00 +0100145 * Write the address of secondary startup into the system-wide flags
146 * register. The BootMonitor waits for this register to become
147 * non-zero.
Russell King862184f2005-11-07 21:05:42 +0000148 */
Catalin Marinasdff2ab12009-07-24 12:33:00 +0100149 __raw_writel(BSYM(virt_to_phys(realview_secondary_startup)),
Colin Tuckley157aed72009-11-04 12:19:05 +0000150 __io_address(REALVIEW_SYS_FLAGSSET));
Russell King862184f2005-11-07 21:05:42 +0000151
152 mb();
153}
154
Russell King7bbb7942006-02-16 11:08:09 +0000155/*
156 * Initialise the CPU possible map early - this describes the CPUs
157 * which may be present or become present in the system.
158 */
159void __init smp_init_cpus(void)
160{
161 unsigned int i, ncores = get_core_count();
162
163 for (i = 0; i < ncores; i++)
Russell Kinge03cdad2009-05-28 14:16:52 +0100164 set_cpu_possible(i, true);
Russell King7bbb7942006-02-16 11:08:09 +0000165}
166
Russell King862184f2005-11-07 21:05:42 +0000167void __init smp_prepare_cpus(unsigned int max_cpus)
168{
169 unsigned int ncores = get_core_count();
170 unsigned int cpu = smp_processor_id();
171 int i;
172
173 /* sanity check */
174 if (ncores == 0) {
175 printk(KERN_ERR
176 "Realview: strange CM count of 0? Default to 1\n");
177
178 ncores = 1;
179 }
180
181 if (ncores > NR_CPUS) {
182 printk(KERN_WARNING
183 "Realview: no. of cores (%d) greater than configured "
184 "maximum of %d - clipping\n",
185 ncores, NR_CPUS);
186 ncores = NR_CPUS;
187 }
188
189 smp_store_cpu_info(cpu);
190
191 /*
192 * are we trying to boot more cores than exist?
193 */
194 if (max_cpus > ncores)
195 max_cpus = ncores;
196
Russell King2a98beb2005-11-09 10:50:29 +0000197 /*
Russell King7bbb7942006-02-16 11:08:09 +0000198 * Initialise the present map, which describes the set of CPUs
199 * actually populated at the present time.
Russell King862184f2005-11-07 21:05:42 +0000200 */
Russell King7bbb7942006-02-16 11:08:09 +0000201 for (i = 0; i < max_cpus; i++)
Russell Kinge03cdad2009-05-28 14:16:52 +0100202 set_cpu_present(i, true);
Russell King862184f2005-11-07 21:05:42 +0000203
204 /*
Catalin Marinasb7b0ba92008-04-18 22:43:08 +0100205 * Initialise the SCU if there are more than one CPU and let
206 * them know where to start. Note that, on modern versions of
207 * MILO, the "poke" doesn't actually do anything until each
208 * individual core is sent a soft interrupt to get it out of
209 * WFI
Russell King862184f2005-11-07 21:05:42 +0000210 */
Catalin Marinasb7b0ba92008-04-18 22:43:08 +0100211 if (max_cpus > 1) {
Russell Kingbc282482009-05-17 18:58:34 +0100212 /*
213 * Enable the local timer or broadcast device for the
214 * boot CPU, but only if we have more than one CPU.
215 */
216 percpu_timer_setup();
217
Russell Kinga8cbcd92009-05-16 11:51:14 +0100218 scu_enable(scu_base_addr());
Russell King862184f2005-11-07 21:05:42 +0000219 poke_milo();
Catalin Marinasb7b0ba92008-04-18 22:43:08 +0100220 }
Russell King862184f2005-11-07 21:05:42 +0000221}