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Commit d4f829dd authored by Andy Lutomirski's avatar Andy Lutomirski Committed by Ingo Molnar
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x86_64/vdso: Move getcpu code from vsyscall_64.c to vdso/vma.c 



This is pure cut-and-paste.  At this point, vsyscall_64.c
contains only code needed for vsyscall emulation, but some of
the comments and function names are still confused.

Signed-off-by: default avatarAndy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/a244daf7d3cbe71afc08ad09fdfe1866ca1f1978.1411494540.git.luto@amacapital.net


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent b9359090

arch/x86/kernel/vsyscall_64.c

+0 −57
Original line number Diff line number Diff line
@@ -332,49 +332,6 @@ int in_gate_area_no_mm(unsigned long addr) 
	return (addr & PAGE_MASK) == VSYSCALL_ADDR;

}



/*

 * Assume __initcall executes before all user space. Hopefully kmod

 * doesn't violate that. We'll find out if it does.

 */

static void vsyscall_set_cpu(int cpu)

{

	unsigned long d;

	unsigned long node = 0;

#ifdef CONFIG_NUMA

	node = cpu_to_node(cpu);

#endif

	if (cpu_has(&cpu_data(cpu), X86_FEATURE_RDTSCP))

		write_rdtscp_aux((node << 12) | cpu);



	/*

	 * Store cpu number in limit so that it can be loaded quickly

	 * in user space in vgetcpu. (12 bits for the CPU and 8 bits for the node)

	 */

	d = 0x0f40000000000ULL;

	d |= cpu;

	d |= (node & 0xf) << 12;

	d |= (node >> 4) << 48;



	write_gdt_entry(get_cpu_gdt_table(cpu), GDT_ENTRY_PER_CPU, &d, DESCTYPE_S);

}



static void cpu_vsyscall_init(void *arg)

{

	/* preemption should be already off */

	vsyscall_set_cpu(raw_smp_processor_id());

}



static int

cpu_vsyscall_notifier(struct notifier_block *n, unsigned long action, void *arg)

{

	long cpu = (long)arg;



	if (action == CPU_ONLINE || action == CPU_ONLINE_FROZEN)

		smp_call_function_single(cpu, cpu_vsyscall_init, NULL, 1);



	return NOTIFY_DONE;

}



void __init map_vsyscall(void)

{

	extern char __vsyscall_page;
@@ -387,17 +344,3 @@ void __init map_vsyscall(void) 
	BUILD_BUG_ON((unsigned long)__fix_to_virt(VSYSCALL_PAGE) !=

		     (unsigned long)VSYSCALL_ADDR);

}
 


static int __init vsyscall_init(void)

{

	cpu_notifier_register_begin();



	on_each_cpu(cpu_vsyscall_init, NULL, 1);

	/* notifier priority > KVM */

	__hotcpu_notifier(cpu_vsyscall_notifier, 30);



	cpu_notifier_register_done();



	return 0;

}

__initcall(vsyscall_init);

arch/x86/vdso/vma.c

+61 −0
Original line number Diff line number Diff line
@@ -10,12 +10,14 @@ 
#include <linux/init.h>

#include <linux/random.h>

#include <linux/elf.h>

#include <linux/cpu.h>

#include <asm/vsyscall.h>

#include <asm/vgtod.h>

#include <asm/proto.h>

#include <asm/vdso.h>

#include <asm/page.h>

#include <asm/hpet.h>

#include <asm/desc.h>



#if defined(CONFIG_X86_64)

unsigned int __read_mostly vdso64_enabled = 1;
@@ -238,3 +240,62 @@ static __init int vdso_setup(char *s) 
}

__setup("vdso=", vdso_setup);

#endif



#ifdef CONFIG_X86_64

/*

 * Assume __initcall executes before all user space. Hopefully kmod

 * doesn't violate that. We'll find out if it does.

 */

static void vsyscall_set_cpu(int cpu)

{

	unsigned long d;

	unsigned long node = 0;

#ifdef CONFIG_NUMA

	node = cpu_to_node(cpu);

#endif

	if (cpu_has(&cpu_data(cpu), X86_FEATURE_RDTSCP))

		write_rdtscp_aux((node << 12) | cpu);



	/*

	 * Store cpu number in limit so that it can be loaded quickly

	 * in user space in vgetcpu. (12 bits for the CPU and 8 bits for the node)

	 */

	d = 0x0f40000000000ULL;

	d |= cpu;

	d |= (node & 0xf) << 12;

	d |= (node >> 4) << 48;



	write_gdt_entry(get_cpu_gdt_table(cpu), GDT_ENTRY_PER_CPU, &d, DESCTYPE_S);

}



static void cpu_vsyscall_init(void *arg)

{

	/* preemption should be already off */

	vsyscall_set_cpu(raw_smp_processor_id());

}



static int

cpu_vsyscall_notifier(struct notifier_block *n, unsigned long action, void *arg)

{

	long cpu = (long)arg;



	if (action == CPU_ONLINE || action == CPU_ONLINE_FROZEN)

		smp_call_function_single(cpu, cpu_vsyscall_init, NULL, 1);



	return NOTIFY_DONE;

}



static int __init vsyscall_init(void)

{

	cpu_notifier_register_begin();



	on_each_cpu(cpu_vsyscall_init, NULL, 1);

	/* notifier priority > KVM */

	__hotcpu_notifier(cpu_vsyscall_notifier, 30);



	cpu_notifier_register_done();



	return 0;

}

__initcall(vsyscall_init);

#endif