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ARM: 7293/1: logical_cpu_map: decouple CPU mapping from SMP

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It turns out that the logical CPU mapping is useful even when !CONFIG_SMP
for manipulation of devices like interrupt and power controllers when
running a UP kernel on a CPU other than 0. This can happen when kexecing
a UP image from an SMP kernel.

In the future, multi-cluster systems running AMP configurations will
require something similar for mapping cluster IDs, so it makes sense to
decouple this logic in preparation for this support.

Acked-by: Yang Bai <hamo.by@gmail.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Reported-by: Joerg Roedel <joerg.roedel@amd.com>
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
2012-01-20 12:01:12 +01:00
committed by Russell King
parent a092f2b153
commit eb50439b92
18 changed files with 35 additions and 31 deletions
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14
arch/arm/kernel/setup.c
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@@ -426,6 +426,20 @@ void cpu_init(void)
: "r14");
}
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);
}
static void __init setup_processor(void)
{
struct proc_info_list *list;