2 * linux/arch/arm/mach-realview/platsmp.c
4 * Copyright (C) 2002 ARM Ltd.
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.
11 #include <linux/init.h>
12 #include <linux/errno.h>
13 #include <linux/delay.h>
14 #include <linux/device.h>
15 #include <linux/jiffies.h>
16 #include <linux/smp.h>
19 #include <asm/cacheflush.h>
20 #include <mach/hardware.h>
21 #include <asm/mach-types.h>
22 #include <asm/localtimer.h>
24 #include <mach/board-eb.h>
25 #include <mach/board-pb11mp.h>
26 #include <mach/board-pbx.h>
27 #include <asm/smp_scu.h>
31 extern void realview_secondary_startup(void);
34 * control for which core is the next to come out of the secondary
37 volatile int __cpuinitdata pen_release
= -1;
39 static void __iomem
*scu_base_addr(void)
41 if (machine_is_realview_eb_mp())
42 return __io_address(REALVIEW_EB11MP_SCU_BASE
);
43 else if (machine_is_realview_pb11mp())
44 return __io_address(REALVIEW_TC11MP_SCU_BASE
);
45 else if (machine_is_realview_pbx() &&
46 (core_tile_pbx11mp() || core_tile_pbxa9mp()))
47 return __io_address(REALVIEW_PBX_TILE_SCU_BASE
);
49 return (void __iomem
*)0;
52 static inline unsigned int get_core_count(void)
54 void __iomem
*scu_base
= scu_base_addr();
56 return scu_get_core_count(scu_base
);
60 static DEFINE_SPINLOCK(boot_lock
);
62 void __cpuinit
platform_secondary_init(unsigned int cpu
)
67 * if any interrupts are already enabled for the primary
68 * core (e.g. timer irq), then they will not have been enabled
71 gic_cpu_init(0, gic_cpu_base_addr
);
74 * let the primary processor know we're out of the
75 * pen, then head off into the C entry point
81 * Synchronise with the boot thread.
83 spin_lock(&boot_lock
);
84 spin_unlock(&boot_lock
);
87 int __cpuinit
boot_secondary(unsigned int cpu
, struct task_struct
*idle
)
89 unsigned long timeout
;
92 * set synchronisation state between this boot processor
93 * and the secondary one
95 spin_lock(&boot_lock
);
98 * The secondary processor is waiting to be released from
99 * the holding pen - release it, then wait for it to flag
100 * that it has been released by resetting pen_release.
102 * Note that "pen_release" is the hardware CPU ID, whereas
103 * "cpu" is Linux's internal ID.
111 * This is a later addition to the booting protocol: the
112 * bootMonitor now puts secondary cores into WFI, so
113 * poke_milo() no longer gets the cores moving; we need
114 * to send a soft interrupt to wake the secondary core.
115 * Use smp_cross_call() for this, since there's little
116 * point duplicating the code here
118 smp_cross_call(cpumask_of(cpu
));
120 timeout
= jiffies
+ (1 * HZ
);
121 while (time_before(jiffies
, timeout
)) {
123 if (pen_release
== -1)
130 * now the secondary core is starting up let it run its
131 * calibrations, then wait for it to finish
133 spin_unlock(&boot_lock
);
135 return pen_release
!= -1 ? -ENOSYS
: 0;
138 static void __init
poke_milo(void)
140 extern void secondary_startup(void);
142 /* nobody is to be released from the pen yet */
146 * write the address of secondary startup into the system-wide
147 * flags register, then clear the bottom two bits, which is what
148 * BootMonitor is waiting for
151 #define REALVIEW_SYS_FLAGSS_OFFSET 0x30
152 __raw_writel(virt_to_phys(realview_secondary_startup
),
153 __io_address(REALVIEW_SYS_BASE
) +
154 REALVIEW_SYS_FLAGSS_OFFSET
);
155 #define REALVIEW_SYS_FLAGSC_OFFSET 0x34
157 __io_address(REALVIEW_SYS_BASE
) +
158 REALVIEW_SYS_FLAGSC_OFFSET
);
165 * Initialise the CPU possible map early - this describes the CPUs
166 * which may be present or become present in the system.
168 void __init
smp_init_cpus(void)
170 unsigned int i
, ncores
= get_core_count();
172 for (i
= 0; i
< ncores
; i
++)
173 set_cpu_possible(i
, true);
176 void __init
smp_prepare_cpus(unsigned int max_cpus
)
178 unsigned int ncores
= get_core_count();
179 unsigned int cpu
= smp_processor_id();
185 "Realview: strange CM count of 0? Default to 1\n");
190 if (ncores
> NR_CPUS
) {
192 "Realview: no. of cores (%d) greater than configured "
193 "maximum of %d - clipping\n",
198 smp_store_cpu_info(cpu
);
201 * are we trying to boot more cores than exist?
203 if (max_cpus
> ncores
)
207 * Initialise the present map, which describes the set of CPUs
208 * actually populated at the present time.
210 for (i
= 0; i
< max_cpus
; i
++)
211 set_cpu_present(i
, true);
214 * Initialise the SCU if there are more than one CPU and let
215 * them know where to start. Note that, on modern versions of
216 * MILO, the "poke" doesn't actually do anything until each
217 * individual core is sent a soft interrupt to get it out of
222 * Enable the local timer or broadcast device for the
223 * boot CPU, but only if we have more than one CPU.
225 percpu_timer_setup();
227 scu_enable(scu_base_addr());