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Commit 73fea175 authored by Ashok Raj's avatar Ashok Raj Committed by Andi Kleen
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[PATCH] i386: Support physical cpu hotplug for x86_64 



This patch enables ACPI based physical CPU hotplug support for x86_64.
Implements acpi_map_lsapic() and acpi_unmap_lsapic() to support physical cpu
hotplug.

Signed-off-by: default avatarAshok Raj <ashok.raj@intel.com>
Signed-off-by: default avatarAndi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@muc.de>
Cc: "Brown, Len" <len.brown@intel.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
parent 40bee2ee

arch/i386/kernel/acpi/boot.c

+65 −4
Original line number Diff line number Diff line
@@ -26,6 +26,7 @@ 
#include <linux/init.h>

#include <linux/acpi.h>

#include <linux/efi.h>

#include <linux/cpumask.h>

#include <linux/module.h>

#include <linux/dmi.h>

#include <linux/irq.h>
@@ -512,16 +513,76 @@ EXPORT_SYMBOL(acpi_register_gsi); 
#ifdef CONFIG_ACPI_HOTPLUG_CPU

int acpi_map_lsapic(acpi_handle handle, int *pcpu)

{

	/* TBD */

	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };

	union acpi_object *obj;

	struct acpi_table_lapic *lapic;

	cpumask_t tmp_map, new_map;

	u8 physid;

	int cpu;



	if (ACPI_FAILURE(acpi_evaluate_object(handle, "_MAT", NULL, &buffer)))

		return -EINVAL;



	if (!buffer.length || !buffer.pointer)

		return -EINVAL;



	obj = buffer.pointer;

	if (obj->type != ACPI_TYPE_BUFFER ||

	    obj->buffer.length < sizeof(*lapic)) {

		kfree(buffer.pointer);

		return -EINVAL;

	}



	lapic = (struct acpi_table_lapic *)obj->buffer.pointer;



	if ((lapic->header.type != ACPI_MADT_LAPIC) ||

	    (!lapic->flags.enabled)) {

		kfree(buffer.pointer);

		return -EINVAL;

	}



	physid = lapic->id;



	kfree(buffer.pointer);

	buffer.length = ACPI_ALLOCATE_BUFFER;

	buffer.pointer = NULL;



	tmp_map = cpu_present_map;

	mp_register_lapic(physid, lapic->flags.enabled);



	/*

	 * If mp_register_lapic successfully generates a new logical cpu

	 * number, then the following will get us exactly what was mapped

	 */

	cpus_andnot(new_map, cpu_present_map, tmp_map);

	if (cpus_empty(new_map)) {

		printk ("Unable to map lapic to logical cpu number\n");

		return -EINVAL;

	}



	cpu = first_cpu(new_map);



	*pcpu = cpu;

	return 0;

}



EXPORT_SYMBOL(acpi_map_lsapic);



int acpi_unmap_lsapic(int cpu)

{

	/* TBD */

	return -EINVAL;

	int i;



	for_each_possible_cpu(i) {

		if (x86_acpiid_to_apicid[i] == x86_cpu_to_apicid[cpu]) {

			x86_acpiid_to_apicid[i] = -1;

			break;

		}

	}

	x86_cpu_to_apicid[cpu] = -1;

	cpu_clear(cpu, cpu_present_map);

	num_processors--;



	return (0);

}



EXPORT_SYMBOL(acpi_unmap_lsapic);

arch/i386/kernel/mpparse.c

+1 −1
Original line number Diff line number Diff line
@@ -69,7 +69,7 @@ unsigned int def_to_bigsmp = 0; 
/* Processor that is doing the boot up */

unsigned int boot_cpu_physical_apicid = -1U;

/* Internal processor count */

static unsigned int __devinitdata num_processors;

unsigned int __cpuinitdata num_processors;



/* Bitmask of physically existing CPUs */

physid_mask_t phys_cpu_present_map;

include/asm-i386/smp.h

+1 −0
Original line number Diff line number Diff line
@@ -84,6 +84,7 @@ static inline int hard_smp_processor_id(void) 


extern int __cpu_disable(void);

extern void __cpu_die(unsigned int cpu);

extern unsigned int num_processors;



#endif /* !__ASSEMBLY__ */