From e15bf9e34b5716e8c4a50b32a98752ff1f53d647 Mon Sep 17 00:00:00 2001 From: Anna-Maria Behnsen Date: Mon, 3 Mar 2025 12:11:07 +0100 Subject: [PATCH] vdso/helpers: Prepare introduction of struct vdso_clock MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 Signed-off-by: Nam Cao Signed-off-by: Thomas Weißschuh Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/all/20250303-vdso-clock-v1-5-c1b5c69a166f@linutronix.de --- 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 41c3087070c7a..28f0707a46c62 100644 --- a/include/vdso/helpers.h +++ b/include/vdso/helpers.h @@ -7,49 +7,53 @@ #include #include -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__ */ -- 2.47.2