mirror of
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2025-08-05 16:54:27 +00:00
7f053812da
Depending on the architecture, building a 32-bit vDSO on a 64-bit kernel
is problematic when some system headers are included.
Minimise the amount of headers by moving needed items, such as
__{get,put}_unaligned_t, into dedicated common headers and in general
use more specific headers, similar to what was done in commit
8165b57bca ("linux/const.h: Extract common header for vDSO") and
commit 8c59ab839f ("lib/vdso: Enable common headers").
On some architectures this results in missing PAGE_SIZE, as was
described by commit 8b3843ae36 ("vdso/datapage: Quick fix - use
asm/page-def.h for ARM64"), so define this if necessary, in the same way
as done prior by commit cffaefd15a ("vdso: Use CONFIG_PAGE_SHIFT in
vdso/datapage.h").
Removing linux/time64.h leads to missing 'struct timespec64' in
x86's asm/pvclock.h. Add a forward declaration of that struct in
that file.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
108 lines
2.7 KiB
C
108 lines
2.7 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#ifndef _ASM_X86_PVCLOCK_H
|
|
#define _ASM_X86_PVCLOCK_H
|
|
|
|
#include <asm/clocksource.h>
|
|
#include <asm/pvclock-abi.h>
|
|
|
|
struct timespec64;
|
|
/* some helper functions for xen and kvm pv clock sources */
|
|
u64 pvclock_clocksource_read(struct pvclock_vcpu_time_info *src);
|
|
u64 pvclock_clocksource_read_nowd(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 timespec64 *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 __always_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 */
|