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/smp.h>
14 #include <linux/io.h>
15 
16 #include <mach/hardware.h>
17 #include <asm/hardware/gic.h>
18 #include <asm/mach-types.h>
19 #include <asm/smp_scu.h>
20 
21 #include <mach/board-eb.h>
22 #include <mach/board-pb11mp.h>
23 #include <mach/board-pbx.h>
24 
25 #include "core.h"
26 
27 extern void versatile_secondary_startup(void);
28 
scu_base_addr(void)29 static void __iomem *scu_base_addr(void)
30 {
31 	if (machine_is_realview_eb_mp())
32 		return __io_address(REALVIEW_EB11MP_SCU_BASE);
33 	else if (machine_is_realview_pb11mp())
34 		return __io_address(REALVIEW_TC11MP_SCU_BASE);
35 	else if (machine_is_realview_pbx() &&
36 		 (core_tile_pbx11mp() || core_tile_pbxa9mp()))
37 		return __io_address(REALVIEW_PBX_TILE_SCU_BASE);
38 	else
39 		return (void __iomem *)0;
40 }
41 
42 /*
43  * Initialise the CPU possible map early - this describes the CPUs
44  * which may be present or become present in the system.
45  */
smp_init_cpus(void)46 void __init smp_init_cpus(void)
47 {
48 	void __iomem *scu_base = scu_base_addr();
49 	unsigned int i, ncores;
50 
51 	ncores = scu_base ? scu_get_core_count(scu_base) : 1;
52 
53 	/* sanity check */
54 	if (ncores > nr_cpu_ids) {
55 		pr_warn("SMP: %u cores greater than maximum (%u), clipping\n",
56 			ncores, nr_cpu_ids);
57 		ncores = nr_cpu_ids;
58 	}
59 
60 	for (i = 0; i < ncores; i++)
61 		set_cpu_possible(i, true);
62 
63 	set_smp_cross_call(gic_raise_softirq);
64 }
65 
platform_smp_prepare_cpus(unsigned int max_cpus)66 void __init platform_smp_prepare_cpus(unsigned int max_cpus)
67 {
68 
69 	scu_enable(scu_base_addr());
70 
71 	/*
72 	 * Write the address of secondary startup into the
73 	 * system-wide flags register. The BootMonitor waits
74 	 * until it receives a soft interrupt, and then the
75 	 * secondary CPU branches to this address.
76 	 */
77 	__raw_writel(virt_to_phys(versatile_secondary_startup),
78 		     __io_address(REALVIEW_SYS_FLAGSSET));
79 }
80