Tuesday, July 3, 2018 12:00 AM, Yongseok Koh: > Subject: Re: [dpdk-dev] [PATCH v2] net/mlx5: add support for 32bit systems > > > > On Jul 2, 2018, at 4:11 AM, Moti Haimovsky <mo...@mellanox.com> wrote: > > > > This patch adds support for building and running mlx5 PMD on 32bit > > systems such as i686. > > > > The main issue to tackle was handling the 32bit access to the UAR as > > quoted from the mlx5 PRM: > > QP and CQ DoorBells require 64-bit writes. For best performance, it is > > recommended to execute the QP/CQ DoorBell as a single 64-bit write > > operation. For platforms that do not support 64 bit writes, it is > > possible to issue the 64 bits DoorBells through two consecutive > > writes, each write 32 bits, as described below: > > * The order of writing each of the Dwords is from lower to upper > > addresses. > > * No other DoorBell can be rung (or even start ringing) in the midst > > of an on-going write of a DoorBell over a given UAR page. > > The last rule implies that in a multi-threaded environment, the access > > to a UAR page (which can be accessible by all threads in the process) > > must be synchronized (for example, using a semaphore) unless an atomic > > write of 64 bits in a single bus operation is guaranteed. Such a > > synchronization is not required for when ringing DoorBells on > > different UAR pages. > > > > Signed-off-by: Moti Haimovsky <mo...@mellanox.com> > > --- > Acked-by: Yongseok Koh <ys...@mellanox.com>
Applied to next-net-mlx, thanks. > > Thanks
