Commit 71056ae2 authored by Marcelo Tosatti's avatar Marcelo Tosatti
Browse files

x86: pvclock: generic pvclock vsyscall initialization 



Originally from Jeremy Fitzhardinge.

Introduce generic, non hypervisor specific, pvclock initialization
routines.

Signed-off-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
parent 582b336e

arch/x86/include/asm/clocksource.h

+1 −0
Original line number Diff line number Diff line
@@ -8,6 +8,7 @@ 
#define VCLOCK_NONE 0  /* No vDSO clock available.	*/

#define VCLOCK_TSC  1  /* vDSO should use vread_tsc.	*/

#define VCLOCK_HPET 2  /* vDSO should use vread_hpet.	*/

#define VCLOCK_PVCLOCK 3 /* vDSO should use vread_pvclock. */



struct arch_clocksource_data {

	int vclock_mode;

arch/x86/include/asm/fixmap.h

+5 −0
Original line number Diff line number Diff line
@@ -19,6 +19,7 @@ 
#include <asm/acpi.h>

#include <asm/apicdef.h>

#include <asm/page.h>

#include <asm/pvclock.h>

#ifdef CONFIG_X86_32

#include <linux/threads.h>

#include <asm/kmap_types.h>
@@ -80,6 +81,10 @@ enum fixed_addresses { 
			    + ((VSYSCALL_END-VSYSCALL_START) >> PAGE_SHIFT) - 1,

	VVAR_PAGE,

	VSYSCALL_HPET,

#endif

#ifdef CONFIG_PARAVIRT_CLOCK

	PVCLOCK_FIXMAP_BEGIN,

	PVCLOCK_FIXMAP_END = PVCLOCK_FIXMAP_BEGIN+PVCLOCK_VSYSCALL_NR_PAGES-1,

#endif

	FIX_DBGP_BASE,

	FIX_EARLYCON_MEM_BASE,

arch/x86/include/asm/pvclock.h

+12 −0
Original line number Diff line number Diff line
@@ -91,4 +91,16 @@ unsigned __pvclock_read_cycles(const struct pvclock_vcpu_time_info *src, 
	return version;

}



struct pvclock_vsyscall_time_info {

	struct pvclock_vcpu_time_info pvti;

	u32 migrate_count;

} __attribute__((__aligned__(SMP_CACHE_BYTES)));



#define PVTI_SIZE sizeof(struct pvclock_vsyscall_time_info)

#define PVCLOCK_VSYSCALL_NR_PAGES (((NR_CPUS-1)/(PAGE_SIZE/PVTI_SIZE))+1)



int __init pvclock_init_vsyscall(struct pvclock_vsyscall_time_info *i,

				 int size);

struct pvclock_vcpu_time_info *pvclock_get_vsyscall_time_info(int cpu);



#endif /* _ASM_X86_PVCLOCK_H */

arch/x86/kernel/pvclock.c

+73 −0
Original line number Diff line number Diff line
@@ -17,6 +17,11 @@ 


#include <linux/kernel.h>

#include <linux/percpu.h>

#include <linux/notifier.h>

#include <linux/sched.h>

#include <linux/gfp.h>

#include <linux/bootmem.h>

#include <asm/fixmap.h>

#include <asm/pvclock.h>



static u8 valid_flags __read_mostly = 0;
@@ -122,3 +127,71 @@ void pvclock_read_wallclock(struct pvclock_wall_clock *wall_clock, 


	set_normalized_timespec(ts, now.tv_sec, now.tv_nsec);

}



static struct pvclock_vsyscall_time_info *pvclock_vdso_info;



static struct pvclock_vsyscall_time_info *

pvclock_get_vsyscall_user_time_info(int cpu)

{

	if (!pvclock_vdso_info) {

		BUG();

		return NULL;

	}



	return &pvclock_vdso_info[cpu];

}



struct pvclock_vcpu_time_info *pvclock_get_vsyscall_time_info(int cpu)

{

	return &pvclock_get_vsyscall_user_time_info(cpu)->pvti;

}



#ifdef CONFIG_X86_64

static int pvclock_task_migrate(struct notifier_block *nb, unsigned long l,

			        void *v)

{

	struct task_migration_notifier *mn = v;

	struct pvclock_vsyscall_time_info *pvti;



	pvti = pvclock_get_vsyscall_user_time_info(mn->from_cpu);



	/* this is NULL when pvclock vsyscall is not initialized */

	if (unlikely(pvti == NULL))

		return NOTIFY_DONE;



	pvti->migrate_count++;



	return NOTIFY_DONE;

}



static struct notifier_block pvclock_migrate = {

	.notifier_call = pvclock_task_migrate,

};



/*

 * Initialize the generic pvclock vsyscall state.  This will allocate

 * a/some page(s) for the per-vcpu pvclock information, set up a

 * fixmap mapping for the page(s)

 */



int __init pvclock_init_vsyscall(struct pvclock_vsyscall_time_info *i,

				 int size)

{

	int idx;



	WARN_ON (size != PVCLOCK_VSYSCALL_NR_PAGES*PAGE_SIZE);



	pvclock_vdso_info = i;



	for (idx = 0; idx <= (PVCLOCK_FIXMAP_END-PVCLOCK_FIXMAP_BEGIN); idx++) {

		__set_fixmap(PVCLOCK_FIXMAP_BEGIN + idx,

			     __pa_symbol(i) + (idx*PAGE_SIZE),

			     PAGE_KERNEL_VVAR);

	}





	register_task_migration_notifier(&pvclock_migrate);



	return 0;

}

#endif