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Commit d6257288 authored by Will Deacon's avatar Will Deacon Committed by Russell King
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ARM: 7060/1: smp: populate logical CPU mapping during boot 



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: default avatarWill Deacon <will.deacon@arm.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent c9018aab

arch/arm/include/asm/smp.h

+6 −0
Original line number Diff line number Diff line
@@ -65,6 +65,12 @@ extern void platform_secondary_init(unsigned int cpu); 
 */

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.

 */

arch/arm/kernel/smp.c

+15 −0
Original line number Diff line number Diff line
@@ -40,6 +40,7 @@ 
#include <asm/tlbflush.h>

#include <asm/ptrace.h>

#include <asm/localtimer.h>

#include <asm/smp_plat.h>



/*

 * 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 */



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

 * per-processor storage.