The following commit has been merged into the timers/vdso branch of tip: Commit-ID: e15bf9e34b5716e8c4a50b32a98752ff1f53d647 Gitweb: https://git.kernel.org/tip/e15bf9e34b5716e8c4a50b32a98752ff1f53d647 Author: Anna-Maria Behnsen <anna-maria@xxxxxxxxxxxxx> AuthorDate: Mon, 03 Mar 2025 12:11:07 +01:00 Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx> CommitterDate: Sat, 08 Mar 2025 14:37:40 +01:00 vdso/helpers: Prepare introduction of struct vdso_clock To support multiple PTP clocks, the VDSO data structure needs to be reworked. All clock specific data will end up in struct vdso_clock and in struct vdso_time_data there will be an array of VDSO clocks. For now, vdso_clock is simply a define which maps vdso_clock to vdso_time_data. Prepare all functions which need the pointer to the vdso_clock array to work well after the structures get reworked. Replace the struct vdso_time_data pointer with a struct vdso_clock pointer where applicable. No functional change. Signed-off-by: Anna-Maria Behnsen <anna-maria@xxxxxxxxxxxxx> Signed-off-by: Nam Cao <namcao@xxxxxxxxxxxxx> Signed-off-by: Thomas Weißschuh <thomas.weissschuh@xxxxxxxxxxxxx> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Link: https://lore.kernel.org/all/20250303-vdso-clock-v1-5-c1b5c69a166f@xxxxxxxxxxxxx --- include/vdso/helpers.h | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) diff --git a/include/vdso/helpers.h b/include/vdso/helpers.h index 41c3087..28f0707 100644 --- a/include/vdso/helpers.h +++ b/include/vdso/helpers.h @@ -7,49 +7,53 @@ #include <asm/barrier.h> #include <vdso/datapage.h> -static __always_inline u32 vdso_read_begin(const struct vdso_time_data *vd) +static __always_inline u32 vdso_read_begin(const struct vdso_clock *vc) { u32 seq; - while (unlikely((seq = READ_ONCE(vd->seq)) & 1)) + while (unlikely((seq = READ_ONCE(vc->seq)) & 1)) cpu_relax(); smp_rmb(); return seq; } -static __always_inline u32 vdso_read_retry(const struct vdso_time_data *vd, +static __always_inline u32 vdso_read_retry(const struct vdso_clock *vc, u32 start) { u32 seq; smp_rmb(); - seq = READ_ONCE(vd->seq); + seq = READ_ONCE(vc->seq); return seq != start; } static __always_inline void vdso_write_begin(struct vdso_time_data *vd) { + struct vdso_clock *vc = vd; + /* * WRITE_ONCE() is required otherwise the compiler can validly tear * updates to vd[x].seq and it is possible that the value seen by the * reader 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); + WRITE_ONCE(vc[CS_HRES_COARSE].seq, vc[CS_HRES_COARSE].seq + 1); + WRITE_ONCE(vc[CS_RAW].seq, vc[CS_RAW].seq + 1); smp_wmb(); } static __always_inline void vdso_write_end(struct vdso_time_data *vd) { + struct vdso_clock *vc = vd; + smp_wmb(); /* * WRITE_ONCE() is required otherwise the compiler can validly tear * updates to vd[x].seq and it is possible that the value seen by the * reader 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); + WRITE_ONCE(vc[CS_HRES_COARSE].seq, vc[CS_HRES_COARSE].seq + 1); + WRITE_ONCE(vc[CS_RAW].seq, vc[CS_RAW].seq + 1); } #endif /* !__ASSEMBLY__ */
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