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Commit eb50439b authored by Will Deacon's avatar Will Deacon Committed by Russell King
Browse files

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



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: default avatarYang Bai <hamo.by@gmail.com>
Acked-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Reported-by: default avatarJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent a092f2b1

arch/arm/common/gic.c

+2 −5
Original line number Diff line number Diff line
@@ -41,6 +41,7 @@ 


#include <asm/irq.h>

#include <asm/exception.h>

#include <asm/smp_plat.h>

#include <asm/mach/irq.h>

#include <asm/hardware/gic.h>
@@ -352,11 +353,7 @@ static void __init gic_dist_init(struct gic_chip_data *gic) 
	unsigned int gic_irqs = gic->gic_irqs;

	struct irq_domain *domain = &gic->domain;

	void __iomem *base = gic_data_dist_base(gic);

	u32 cpu = 0;



#ifdef CONFIG_SMP

	cpu = cpu_logical_map(smp_processor_id());

#endif

	u32 cpu = cpu_logical_map(smp_processor_id());



	cpumask = 1 << cpu;

	cpumask |= cpumask << 8;

arch/arm/include/asm/smp.h

+0 −6
Original line number Diff line number Diff line
@@ -70,12 +70,6 @@ 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/include/asm/smp_plat.h

+6 −0
Original line number Diff line number Diff line
@@ -43,4 +43,10 @@ static inline int cache_ops_need_broadcast(void) 
}

#endif



/*

 * Logical CPU mapping.

 */

extern int __cpu_logical_map[];

#define cpu_logical_map(cpu)	__cpu_logical_map[cpu]



#endif

arch/arm/kernel/setup.c

+14 −0
Original line number Diff line number Diff line
@@ -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;

arch/arm/kernel/smp.c

+0 −14
Original line number Diff line number Diff line
@@ -233,20 +233,6 @@ 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.