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Date: Mon, 17 Feb 2020 10:36:29 +0300 From: Alexander Lobakin <alobakin@...nk.ru> To: Jason Gunthorpe <jgg@...pe.ca> Cc: Leon Romanovsky <leon@...nel.org>, Doug Ledford <dledford@...hat.com>, Randy Dunlap <rdunlap@...radead.org>, Maxim Mikityanskiy <maximmi@...lanox.com>, Alexander Lobakin <alobakin@...nk.ru>, linux-rdma@...r.kernel.org, linux-kernel@...r.kernel.org Subject: [PATCH rdma] IB/mlx5: Optimize u64 division on 32-bit arches Commit f164be8c0366 ("IB/mlx5: Extend caps stage to handle VAR capabilities") introduced a straight "/" division of the u64 variable "bar_size". This was fixed with commit 685eff513183 ("IB/mlx5: Use div64_u64 for num_var_hw_entries calculation"). However, div64_u64() is redundant here as mlx5_var_table::stride_size is of type u32. Make the actual code way more optimized on 32-bit kernels using div_u64() and fix 80 chars break-through by the way. Fixes: 685eff513183 ("IB/mlx5: Use div64_u64 for num_var_hw_entries calculation") Signed-off-by: Alexander Lobakin <alobakin@...nk.ru> --- drivers/infiniband/hw/mlx5/main.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/infiniband/hw/mlx5/main.c b/drivers/infiniband/hw/mlx5/main.c index e4bcfa81b70a..026391e4ceb4 100644 --- a/drivers/infiniband/hw/mlx5/main.c +++ b/drivers/infiniband/hw/mlx5/main.c @@ -6545,7 +6545,8 @@ static int mlx5_ib_init_var_table(struct mlx5_ib_dev *dev) doorbell_bar_offset); bar_size = (1ULL << log_doorbell_bar_size) * 4096; var_table->stride_size = 1ULL << log_doorbell_stride; - var_table->num_var_hw_entries = div64_u64(bar_size, var_table->stride_size); + var_table->num_var_hw_entries = div_u64(bar_size, + var_table->stride_size); mutex_init(&var_table->bitmap_lock); var_table->bitmap = bitmap_zalloc(var_table->num_var_hw_entries, GFP_KERNEL); -- 2.25.0
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