| /* SPDX-License-Identifier: GPL-2.0 */ |
| #include <vdso/datapage.h> |
| static __always_inline u32 vdso_read_begin(const struct vdso_data *vd) |
| while (unlikely((seq = READ_ONCE(vd->seq)) & 1)) |
| static __always_inline u32 vdso_read_retry(const struct vdso_data *vd, |
| seq = READ_ONCE(vd->seq); |
| static __always_inline void vdso_write_begin(struct vdso_data *vd) |
| * WRITE_ONCE it is required otherwise the compiler can validly tear |
| * updates to vd[x].seq and it is possible that the value seen by the |
| * reader it is inconsistent. |
| WRITE_ONCE(vd[CS_HRES_COARSE].seq, vd[CS_HRES_COARSE].seq + 1); |
| WRITE_ONCE(vd[CS_RAW].seq, vd[CS_RAW].seq + 1); |
| static __always_inline void vdso_write_end(struct vdso_data *vd) |
| * WRITE_ONCE it is required otherwise the compiler can validly tear |
| * updates to vd[x].seq and it is possible that the value seen by the |
| * reader it is inconsistent. |
| WRITE_ONCE(vd[CS_HRES_COARSE].seq, vd[CS_HRES_COARSE].seq + 1); |
| WRITE_ONCE(vd[CS_RAW].seq, vd[CS_RAW].seq + 1); |
| #endif /* !__ASSEMBLY__ */ |
| #endif /* __VDSO_HELPERS_H */ |