[mirror_ubuntu-artful-kernel.git] / arch / x86 / include / asm / pvclock.h

#ifndef _ASM_X86_PVCLOCK_H
#define _ASM_X86_PVCLOCK_H

#include <linux/clocksource.h>
#include <asm/pvclock-abi.h>

#ifdef CONFIG_KVM_GUEST
extern struct pvclock_vsyscall_time_info *pvclock_pvti_cpu0_va(void);
#else
static inline struct pvclock_vsyscall_time_info *pvclock_pvti_cpu0_va(void)
{
	return NULL;
}
#endif

/* some helper functions for xen and kvm pv clock sources */
u64 pvclock_clocksource_read(struct pvclock_vcpu_time_info *src);
u8 pvclock_read_flags(struct pvclock_vcpu_time_info *src);
void pvclock_set_flags(u8 flags);
unsigned long pvclock_tsc_khz(struct pvclock_vcpu_time_info *src);
void pvclock_read_wallclock(struct pvclock_wall_clock *wall,
			    struct pvclock_vcpu_time_info *vcpu,
			    struct timespec *ts);
void pvclock_resume(void);

void pvclock_touch_watchdogs(void);

static __always_inline
unsigned pvclock_read_begin(const struct pvclock_vcpu_time_info *src)
{
	unsigned version = src->version & ~1;
	/* Make sure that the version is read before the data. */
	virt_rmb();
	return version;
}

static __always_inline
bool pvclock_read_retry(const struct pvclock_vcpu_time_info *src,
			unsigned version)
{
	/* Make sure that the version is re-read after the data. */
	virt_rmb();
	return unlikely(version != src->version);
}

/*
 * Scale a 64-bit delta by scaling and multiplying by a 32-bit fraction,
 * yielding a 64-bit result.
 */
static inline u64 pvclock_scale_delta(u64 delta, u32 mul_frac, int shift)
{
	u64 product;
#ifdef __i386__
	u32 tmp1, tmp2;
#else
	ulong tmp;
#endif

	if (shift < 0)
		delta >>= -shift;
	else
		delta <<= shift;

#ifdef __i386__
	__asm__ (
		"mul  %5       ; "
		"mov  %4,%%eax ; "
		"mov  %%edx,%4 ; "
		"mul  %5       ; "
		"xor  %5,%5    ; "
		"add  %4,%%eax ; "
		"adc  %5,%%edx ; "
		: "=A" (product), "=r" (tmp1), "=r" (tmp2)
		: "a" ((u32)delta), "1" ((u32)(delta >> 32)), "2" (mul_frac) );
#elif defined(__x86_64__)
	__asm__ (
		"mulq %[mul_frac] ; shrd $32, %[hi], %[lo]"
		: [lo]"=a"(product),
		  [hi]"=d"(tmp)
		: "0"(delta),
		  [mul_frac]"rm"((u64)mul_frac));
#else
#error implement me!
#endif

	return product;
}

static __always_inline
u64 __pvclock_read_cycles(const struct pvclock_vcpu_time_info *src, u64 tsc)
{
	u64 delta = tsc - src->tsc_timestamp;
	u64 offset = pvclock_scale_delta(delta, src->tsc_to_system_mul,
					     src->tsc_shift);
	return src->system_time + offset;
}

struct pvclock_vsyscall_time_info {
	struct pvclock_vcpu_time_info pvti;
} __attribute__((__aligned__(SMP_CACHE_BYTES)));

#define PVTI_SIZE sizeof(struct pvclock_vsyscall_time_info)

#endif /* _ASM_X86_PVCLOCK_H */
Commit	Line	Data
1965aae3 PA	1	#ifndef _ASM_X86_PVCLOCK_H
1965aae3 PA	2	#define _ASM_X86_PVCLOCK_H
7af192c9 GH	3
	4	#include <linux/clocksource.h>
	5	#include <asm/pvclock-abi.h>
	6
8705d603	7	#ifdef CONFIG_KVM_GUEST
dac16fba AL	8	extern struct pvclock_vsyscall_time_info *pvclock_pvti_cpu0_va(void);
	9	#else
	10	static inline struct pvclock_vsyscall_time_info *pvclock_pvti_cpu0_va(void)
	11	{
	12	return NULL;
	13	}
	14	#endif
	15
7af192c9	16	/* some helper functions for xen and kvm pv clock sources */
a5a1d1c2	17	u64 pvclock_clocksource_read(struct pvclock_vcpu_time_info *src);
2697902b	18	u8 pvclock_read_flags(struct pvclock_vcpu_time_info *src);
424c32f1	19	void pvclock_set_flags(u8 flags);
3807f345	20	unsigned long pvclock_tsc_khz(struct pvclock_vcpu_time_info *src);
7af192c9 GH	21	void pvclock_read_wallclock(struct pvclock_wall_clock *wall,
	22	struct pvclock_vcpu_time_info *vcpu,
	23	struct timespec *ts);
e7a3481c	24	void pvclock_resume(void);
7af192c9	25
d63285e9 MT	26	void pvclock_touch_watchdogs(void);
d63285e9 MT	27
3aed64f6 PB	28	static __always_inline
	29	unsigned pvclock_read_begin(const struct pvclock_vcpu_time_info *src)
	30	{
	31	unsigned version = src->version & ~1;
	32	/* Make sure that the version is read before the data. */
	33	virt_rmb();
	34	return version;
	35	}
	36
	37	static __always_inline
	38	bool pvclock_read_retry(const struct pvclock_vcpu_time_info *src,
	39	unsigned version)
	40	{
	41	/* Make sure that the version is re-read after the data. */
	42	virt_rmb();
	43	return unlikely(version != src->version);
	44	}
	45
347bb444 ZA	46	/*
	47	* Scale a 64-bit delta by scaling and multiplying by a 32-bit fraction,
	48	* yielding a 64-bit result.
	49	*/
	50	static inline u64 pvclock_scale_delta(u64 delta, u32 mul_frac, int shift)
	51	{
	52	u64 product;
	53	#ifdef __i386__
	54	u32 tmp1, tmp2;
de2d1a52 ZA	55	#else
de2d1a52 ZA	56	ulong tmp;
347bb444 ZA	57	#endif
	58
	59	if (shift < 0)
	60	delta >>= -shift;
	61	else
	62	delta <<= shift;
	63
	64	#ifdef __i386__
	65	__asm__ (
	66	"mul %5 ; "
	67	"mov %4,%%eax ; "
	68	"mov %%edx,%4 ; "
	69	"mul %5 ; "
	70	"xor %5,%5 ; "
	71	"add %4,%%eax ; "
	72	"adc %5,%%edx ; "
	73	: "=A" (product), "=r" (tmp1), "=r" (tmp2)
	74	: "a" ((u32)delta), "1" ((u32)(delta >> 32)), "2" (mul_frac) );
	75	#elif defined(__x86_64__)
	76	__asm__ (
3b217116	77	"mulq %[mul_frac] ; shrd $32, %[hi], %[lo]"
de2d1a52 ZA	78	: [lo]"=a"(product),
	79	[hi]"=d"(tmp)
	80	: "0"(delta),
	81	[mul_frac]"rm"((u64)mul_frac));
347bb444 ZA	82	#else
	83	#error implement me!
	84	#endif
	85
	86	return product;
	87	}
	88
dce2db0a	89	static __always_inline
a5a1d1c2	90	u64 __pvclock_read_cycles(const struct pvclock_vcpu_time_info *src, u64 tsc)
dce2db0a	91	{
108b249c	92	u64 delta = tsc - src->tsc_timestamp;
a5a1d1c2	93	u64 offset = pvclock_scale_delta(delta, src->tsc_to_system_mul,
3aed64f6 PB	94	src->tsc_shift);
3aed64f6 PB	95	return src->system_time + offset;
dce2db0a MT	96	}
dce2db0a MT	97
71056ae2 MT	98	struct pvclock_vsyscall_time_info {
71056ae2 MT	99	struct pvclock_vcpu_time_info pvti;
71056ae2 MT	100	} __attribute__((__aligned__(SMP_CACHE_BYTES)));
	101
	102	#define PVTI_SIZE sizeof(struct pvclock_vsyscall_time_info)
71056ae2	103
1965aae3	104	#endif /* _ASM_X86_PVCLOCK_H */