From 24d33d2c8e92abffe1f0653d42fc65b8f164a6d9 Mon Sep 17 00:00:00 2001 From: Feras Daoud Date: Tue, 16 Jan 2018 20:08:40 +0200 Subject: [PATCH] net/mlx5e: Add clock info page to mlx5 core devices Adds a new page to mlx5 core containing clock info data that allows user level applications to translate between cqe timestamp to nanoseconds. The information stored into this page is represented through mlx5_ib_clock_info. In order to synchronize between kernel and user space a sequence number is incremented at the beginning and end of each update. An odd number means the data is being updated while an even means the access was already done. To guarantee that the data structure was accessed atomically user will: repeat: seq1 = goto while odd seq2 = if seq1 != seq2 goto repeat Reviewed-by: Yishai Hadas Reviewed-by: Jason Gunthorpe Reviewed-by: Alex Vesker Signed-off-by: Feras Daoud Signed-off-by: Eitan Rabin Signed-off-by: Leon Romanovsky Signed-off-by: Doug Ledford --- .../ethernet/mellanox/mlx5/core/lib/clock.c | 55 +++++++++++++++++++ include/linux/mlx5/driver.h | 3 + include/uapi/rdma/mlx5-abi.h | 16 ++++++ 3 files changed, 74 insertions(+) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/lib/clock.c b/drivers/net/ethernet/mellanox/mlx5/core/lib/clock.c index fa8aed62b231..4b6cb9b38686 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/lib/clock.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/lib/clock.c @@ -31,6 +31,8 @@ */ #include +#include +#include #include "en.h" enum { @@ -71,6 +73,28 @@ static u64 read_internal_timer(const struct cyclecounter *cc) return mlx5_read_internal_timer(mdev) & cc->mask; } +static void mlx5_update_clock_info_page(struct mlx5_core_dev *mdev) +{ + struct mlx5_ib_clock_info *clock_info = mdev->clock_info; + struct mlx5_clock *clock = &mdev->clock; + u32 sign; + + if (!clock_info) + return; + + sign = smp_load_acquire(&clock_info->sign); + smp_store_mb(clock_info->sign, + sign | MLX5_IB_CLOCK_INFO_KERNEL_UPDATING); + + clock_info->cycles = clock->tc.cycle_last; + clock_info->mult = clock->cycles.mult; + clock_info->nsec = clock->tc.nsec; + clock_info->frac = clock->tc.frac; + + smp_store_release(&clock_info->sign, + sign + MLX5_IB_CLOCK_INFO_KERNEL_UPDATING * 2); +} + static void mlx5_pps_out(struct work_struct *work) { struct mlx5_pps *pps_info = container_of(work, struct mlx5_pps, @@ -109,6 +133,7 @@ static void mlx5_timestamp_overflow(struct work_struct *work) write_lock_irqsave(&clock->lock, flags); timecounter_read(&clock->tc); + mlx5_update_clock_info_page(clock->mdev); write_unlock_irqrestore(&clock->lock, flags); schedule_delayed_work(&clock->overflow_work, clock->overflow_period); } @@ -123,6 +148,7 @@ static int mlx5_ptp_settime(struct ptp_clock_info *ptp, write_lock_irqsave(&clock->lock, flags); timecounter_init(&clock->tc, &clock->cycles, ns); + mlx5_update_clock_info_page(clock->mdev); write_unlock_irqrestore(&clock->lock, flags); return 0; @@ -152,6 +178,7 @@ static int mlx5_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta) write_lock_irqsave(&clock->lock, flags); timecounter_adjtime(&clock->tc, delta); + mlx5_update_clock_info_page(clock->mdev); write_unlock_irqrestore(&clock->lock, flags); return 0; @@ -179,6 +206,7 @@ static int mlx5_ptp_adjfreq(struct ptp_clock_info *ptp, s32 delta) timecounter_read(&clock->tc); clock->cycles.mult = neg_adj ? clock->nominal_c_mult - diff : clock->nominal_c_mult + diff; + mlx5_update_clock_info_page(clock->mdev); write_unlock_irqrestore(&clock->lock, flags); return 0; @@ -470,6 +498,7 @@ void mlx5_init_clock(struct mlx5_core_dev *mdev) clock->cycles.shift); clock->nominal_c_mult = clock->cycles.mult; clock->cycles.mask = CLOCKSOURCE_MASK(41); + clock->mdev = mdev; timecounter_init(&clock->tc, &clock->cycles, ktime_to_ns(ktime_get_real())); @@ -482,6 +511,25 @@ void mlx5_init_clock(struct mlx5_core_dev *mdev) do_div(ns, NSEC_PER_SEC / 2 / HZ); clock->overflow_period = ns; + mdev->clock_info_page = alloc_page(GFP_KERNEL); + if (mdev->clock_info_page) { + mdev->clock_info = kmap(mdev->clock_info_page); + if (!mdev->clock_info) { + __free_page(mdev->clock_info_page); + mlx5_core_warn(mdev, "failed to map clock page\n"); + } else { + mdev->clock_info->sign = 0; + mdev->clock_info->nsec = clock->tc.nsec; + mdev->clock_info->cycles = clock->tc.cycle_last; + mdev->clock_info->mask = clock->cycles.mask; + mdev->clock_info->mult = clock->nominal_c_mult; + mdev->clock_info->shift = clock->cycles.shift; + mdev->clock_info->frac = clock->tc.frac; + mdev->clock_info->overflow_period = + clock->overflow_period; + } + } + INIT_WORK(&clock->pps_info.out_work, mlx5_pps_out); INIT_DELAYED_WORK(&clock->overflow_work, mlx5_timestamp_overflow); if (clock->overflow_period) @@ -521,5 +569,12 @@ void mlx5_cleanup_clock(struct mlx5_core_dev *mdev) cancel_work_sync(&clock->pps_info.out_work); cancel_delayed_work_sync(&clock->overflow_work); + + if (mdev->clock_info) { + kunmap(mdev->clock_info_page); + __free_page(mdev->clock_info_page); + mdev->clock_info = NULL; + } + kfree(clock->ptp_info.pin_config); } diff --git a/include/linux/mlx5/driver.h b/include/linux/mlx5/driver.h index 9136e35f2f7e..c403151133e9 100644 --- a/include/linux/mlx5/driver.h +++ b/include/linux/mlx5/driver.h @@ -797,6 +797,7 @@ struct mlx5_clock { u32 nominal_c_mult; unsigned long overflow_period; struct delayed_work overflow_work; + struct mlx5_core_dev *mdev; struct ptp_clock *ptp; struct ptp_clock_info ptp_info; struct mlx5_pps pps_info; @@ -844,6 +845,8 @@ struct mlx5_core_dev { struct cpu_rmap *rmap; #endif struct mlx5_clock clock; + struct mlx5_ib_clock_info *clock_info; + struct page *clock_info_page; }; struct mlx5_db { diff --git a/include/uapi/rdma/mlx5-abi.h b/include/uapi/rdma/mlx5-abi.h index f6d319dfc7bf..0299deed71a2 100644 --- a/include/uapi/rdma/mlx5-abi.h +++ b/include/uapi/rdma/mlx5-abi.h @@ -381,4 +381,20 @@ struct mlx5_ib_modify_wq { __u32 comp_mask; __u32 reserved; }; + +struct mlx5_ib_clock_info { + __u32 sign; + __u32 resv; + __u64 nsec; + __u64 cycles; + __u64 frac; + __u32 mult; + __u32 shift; + __u64 mask; + __u64 overflow_period; +}; + +enum { + MLX5_IB_CLOCK_INFO_KERNEL_UPDATING = 1, +}; #endif /* MLX5_ABI_USER_H */ -- GitLab