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ARM: 7060/1: smp: populate logical CPU mapping during boot

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To allow booting Linux on a CPU with physical ID != 0, we need to
provide a mapping from the logical CPU number to the physical CPU
number.

This patch adds such a mapping and populates it during boot.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Will Deacon 2011-08-23 22:19:29 +01:00 committed by Russell King
parent c9018aab8e
commit d6257288c4
2 changed files with 21 additions and 0 deletions
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6
arch/arm/include/asm/smp.h
View File

@ -65,6 +65,12 @@ extern void platform_secondary_init(unsigned int cpu);
*/ */
extern void platform_smp_prepare_cpus(unsigned int); extern void platform_smp_prepare_cpus(unsigned int);
/*
* Logical CPU mapping.
*/
extern int __cpu_logical_map[NR_CPUS];
#define cpu_logical_map(cpu) __cpu_logical_map[cpu]
/* /*
* Initial data for bringing up a secondary CPU. * Initial data for bringing up a secondary CPU.
*/ */

15
arch/arm/kernel/smp.c
View File

@ -40,6 +40,7 @@
#include <asm/tlbflush.h> #include <asm/tlbflush.h>
#include <asm/ptrace.h> #include <asm/ptrace.h>
#include <asm/localtimer.h> #include <asm/localtimer.h>
#include <asm/smp_plat.h>
/* /*
* as from 2.5, kernels no longer have an init_tasks structure * as from 2.5, kernels no longer have an init_tasks structure
@ -260,6 +261,20 @@ void __ref cpu_die(void)
} }
#endif /* CONFIG_HOTPLUG_CPU */ #endif /* CONFIG_HOTPLUG_CPU */
int __cpu_logical_map[NR_CPUS];
void __init smp_setup_processor_id(void)
{
int i;
u32 cpu = is_smp() ? read_cpuid_mpidr() & 0xff : 0;
cpu_logical_map(0) = cpu;
for (i = 1; i < NR_CPUS; ++i)
cpu_logical_map(i) = i == cpu ? 0 : i;
printk(KERN_INFO "Booting Linux on physical CPU %d\n", cpu);
}
/* /*
* Called by both boot and secondaries to move global data into * Called by both boot and secondaries to move global data into
* per-processor storage. * per-processor storage.