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

/* SPDX-License-Identifier: GPL-2.0 */
#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 */
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)

#ifdef CONFIG_PARAVIRT_CLOCK
void pvclock_set_pvti_cpu0_va(struct pvclock_vsyscall_time_info *pvti);
struct pvclock_vsyscall_time_info *pvclock_get_pvti_cpu0_va(void);
#else
static inline struct pvclock_vsyscall_time_info *pvclock_get_pvti_cpu0_va(void)
{
	return NULL;
}
#endif

#endif /* _ASM_X86_PVCLOCK_H */
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
1965aae3 PA	2	#ifndef _ASM_X86_PVCLOCK_H
1965aae3 PA	3	#define _ASM_X86_PVCLOCK_H
7af192c9 GH	4
	5	#include <linux/clocksource.h>
	6	#include <asm/pvclock-abi.h>
	7
	8	/* some helper functions for xen and kvm pv clock sources */
a5a1d1c2	9	u64 pvclock_clocksource_read(struct pvclock_vcpu_time_info *src);
2697902b	10	u8 pvclock_read_flags(struct pvclock_vcpu_time_info *src);
424c32f1	11	void pvclock_set_flags(u8 flags);
3807f345	12	unsigned long pvclock_tsc_khz(struct pvclock_vcpu_time_info *src);
7af192c9 GH	13	void pvclock_read_wallclock(struct pvclock_wall_clock *wall,
	14	struct pvclock_vcpu_time_info *vcpu,
	15	struct timespec *ts);
e7a3481c	16	void pvclock_resume(void);
7af192c9	17
d63285e9 MT	18	void pvclock_touch_watchdogs(void);
d63285e9 MT	19
3aed64f6 PB	20	static __always_inline
	21	unsigned pvclock_read_begin(const struct pvclock_vcpu_time_info *src)
	22	{
	23	unsigned version = src->version & ~1;
	24	/* Make sure that the version is read before the data. */
	25	virt_rmb();
	26	return version;
	27	}
	28
	29	static __always_inline
	30	bool pvclock_read_retry(const struct pvclock_vcpu_time_info *src,
	31	unsigned version)
	32	{
	33	/* Make sure that the version is re-read after the data. */
	34	virt_rmb();
	35	return unlikely(version != src->version);
	36	}
	37
347bb444 ZA	38	/*
	39	* Scale a 64-bit delta by scaling and multiplying by a 32-bit fraction,
	40	* yielding a 64-bit result.
	41	*/
	42	static inline u64 pvclock_scale_delta(u64 delta, u32 mul_frac, int shift)
	43	{
	44	u64 product;
	45	#ifdef __i386__
	46	u32 tmp1, tmp2;
de2d1a52 ZA	47	#else
de2d1a52 ZA	48	ulong tmp;
347bb444 ZA	49	#endif
	50
	51	if (shift < 0)
	52	delta >>= -shift;
	53	else
	54	delta <<= shift;
	55
	56	#ifdef __i386__
	57	__asm__ (
	58	"mul %5 ; "
	59	"mov %4,%%eax ; "
	60	"mov %%edx,%4 ; "
	61	"mul %5 ; "
	62	"xor %5,%5 ; "
	63	"add %4,%%eax ; "
	64	"adc %5,%%edx ; "
	65	: "=A" (product), "=r" (tmp1), "=r" (tmp2)
	66	: "a" ((u32)delta), "1" ((u32)(delta >> 32)), "2" (mul_frac) );
	67	#elif defined(__x86_64__)
	68	__asm__ (
3b217116	69	"mulq %[mul_frac] ; shrd $32, %[hi], %[lo]"
de2d1a52 ZA	70	: [lo]"=a"(product),
	71	[hi]"=d"(tmp)
	72	: "0"(delta),
	73	[mul_frac]"rm"((u64)mul_frac));
347bb444 ZA	74	#else
	75	#error implement me!
	76	#endif
	77
	78	return product;
	79	}
	80
dce2db0a	81	static __always_inline
a5a1d1c2	82	u64 __pvclock_read_cycles(const struct pvclock_vcpu_time_info *src, u64 tsc)
dce2db0a	83	{
108b249c	84	u64 delta = tsc - src->tsc_timestamp;
a5a1d1c2	85	u64 offset = pvclock_scale_delta(delta, src->tsc_to_system_mul,
3aed64f6 PB	86	src->tsc_shift);
3aed64f6 PB	87	return src->system_time + offset;
dce2db0a MT	88	}
dce2db0a MT	89
71056ae2 MT	90	struct pvclock_vsyscall_time_info {
71056ae2 MT	91	struct pvclock_vcpu_time_info pvti;
71056ae2 MT	92	} __attribute__((__aligned__(SMP_CACHE_BYTES)));
	93
	94	#define PVTI_SIZE sizeof(struct pvclock_vsyscall_time_info)
71056ae2	95
9f08890a JM	96	#ifdef CONFIG_PARAVIRT_CLOCK
	97	void pvclock_set_pvti_cpu0_va(struct pvclock_vsyscall_time_info *pvti);
	98	struct pvclock_vsyscall_time_info *pvclock_get_pvti_cpu0_va(void);
	99	#else
	100	static inline struct pvclock_vsyscall_time_info *pvclock_get_pvti_cpu0_va(void)
	101	{
	102	return NULL;
	103	}
	104	#endif
	105
1965aae3	106	#endif /* _ASM_X86_PVCLOCK_H */