[linux-2.6-block.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>

/* some helper functions for xen and kvm pv clock sources */
cycle_t 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);

/*
 * 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_get_nsec_offset(const struct pvclock_vcpu_time_info *src)
{
	u64 delta = __native_read_tsc() - src->tsc_timestamp;
	return pvclock_scale_delta(delta, src->tsc_to_system_mul,
				   src->tsc_shift);
}

static __always_inline
unsigned __pvclock_read_cycles(const struct pvclock_vcpu_time_info *src,
			       cycle_t *cycles, u8 *flags)
{
	unsigned version;
	cycle_t ret, offset;
	u8 ret_flags;

	version = src->version;
	/* Note: emulated platforms which do not advertise SSE2 support
	 * result in kvmclock not using the necessary RDTSC barriers.
	 * Without barriers, it is possible that RDTSC instruction reads from
	 * the time stamp counter outside rdtsc_barrier protected section
	 * below, resulting in violation of monotonicity.
	 */
	rdtsc_barrier();
	offset = pvclock_get_nsec_offset(src);
	ret = src->system_time + offset;
	ret_flags = src->flags;
	rdtsc_barrier();

	*cycles = ret;
	*flags = ret_flags;
	return version;
}

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)
#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 */
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
	7	/* some helper functions for xen and kvm pv clock sources */
	8	cycle_t pvclock_clocksource_read(struct pvclock_vcpu_time_info *src);
2697902b	9	u8 pvclock_read_flags(struct pvclock_vcpu_time_info *src);
424c32f1	10	void pvclock_set_flags(u8 flags);
3807f345	11	unsigned long pvclock_tsc_khz(struct pvclock_vcpu_time_info *src);
7af192c9 GH	12	void pvclock_read_wallclock(struct pvclock_wall_clock *wall,
	13	struct pvclock_vcpu_time_info *vcpu,
	14	struct timespec *ts);
e7a3481c	15	void pvclock_resume(void);
7af192c9	16
d63285e9 MT	17	void pvclock_touch_watchdogs(void);
d63285e9 MT	18
347bb444 ZA	19	/*
	20	* Scale a 64-bit delta by scaling and multiplying by a 32-bit fraction,
	21	* yielding a 64-bit result.
	22	*/
	23	static inline u64 pvclock_scale_delta(u64 delta, u32 mul_frac, int shift)
	24	{
	25	u64 product;
	26	#ifdef __i386__
	27	u32 tmp1, tmp2;
de2d1a52 ZA	28	#else
de2d1a52 ZA	29	ulong tmp;
347bb444 ZA	30	#endif
	31
	32	if (shift < 0)
	33	delta >>= -shift;
	34	else
	35	delta <<= shift;
	36
	37	#ifdef __i386__
	38	__asm__ (
	39	"mul %5 ; "
	40	"mov %4,%%eax ; "
	41	"mov %%edx,%4 ; "
	42	"mul %5 ; "
	43	"xor %5,%5 ; "
	44	"add %4,%%eax ; "
	45	"adc %5,%%edx ; "
	46	: "=A" (product), "=r" (tmp1), "=r" (tmp2)
	47	: "a" ((u32)delta), "1" ((u32)(delta >> 32)), "2" (mul_frac) );
	48	#elif defined(__x86_64__)
	49	__asm__ (
3b217116	50	"mulq %[mul_frac] ; shrd $32, %[hi], %[lo]"
de2d1a52 ZA	51	: [lo]"=a"(product),
	52	[hi]"=d"(tmp)
	53	: "0"(delta),
	54	[mul_frac]"rm"((u64)mul_frac));
347bb444 ZA	55	#else
	56	#error implement me!
	57	#endif
	58
	59	return product;
	60	}
	61
dce2db0a MT	62	static __always_inline
	63	u64 pvclock_get_nsec_offset(const struct pvclock_vcpu_time_info *src)
	64	{
	65	u64 delta = __native_read_tsc() - src->tsc_timestamp;
	66	return pvclock_scale_delta(delta, src->tsc_to_system_mul,
	67	src->tsc_shift);
	68	}
	69
	70	static __always_inline
	71	unsigned __pvclock_read_cycles(const struct pvclock_vcpu_time_info *src,
	72	cycle_t cycles, u8 flags)
	73	{
	74	unsigned version;
	75	cycle_t ret, offset;
	76	u8 ret_flags;
	77
	78	version = src->version;
189e1173 MT	79	/* Note: emulated platforms which do not advertise SSE2 support
	80	* result in kvmclock not using the necessary RDTSC barriers.
	81	* Without barriers, it is possible that RDTSC instruction reads from
	82	* the time stamp counter outside rdtsc_barrier protected section
	83	* below, resulting in violation of monotonicity.
	84	*/
dce2db0a MT	85	rdtsc_barrier();
	86	offset = pvclock_get_nsec_offset(src);
	87	ret = src->system_time + offset;
	88	ret_flags = src->flags;
	89	rdtsc_barrier();
	90
	91	*cycles = ret;
	92	*flags = ret_flags;
	93	return version;
	94	}
	95
71056ae2 MT	96	struct pvclock_vsyscall_time_info {
71056ae2 MT	97	struct pvclock_vcpu_time_info pvti;
71056ae2 MT	98	} __attribute__((__aligned__(SMP_CACHE_BYTES)));
	99
	100	#define PVTI_SIZE sizeof(struct pvclock_vsyscall_time_info)
	101	#define PVCLOCK_VSYSCALL_NR_PAGES (((NR_CPUS-1)/(PAGE_SIZE/PVTI_SIZE))+1)
	102
	103	int __init pvclock_init_vsyscall(struct pvclock_vsyscall_time_info *i,
	104	int size);
	105	struct pvclock_vcpu_time_info *pvclock_get_vsyscall_time_info(int cpu);
	106
1965aae3	107	#endif /* _ASM_X86_PVCLOCK_H */