Re: [PATCH v2 00/17] RDMA: Improve use of umem in DMA drivers

From: Jason Gunthorpe <jgg@nvidia.com>
To: Adit Ranadive <aditr@vmware.com>,
	Ariel Elior <aelior@marvell.com>,
	Potnuri Bharat Teja <bharat@chelsio.com>,
	"David S. Miller" <davem@davemloft.net>,
	Devesh Sharma <devesh.sharma@broadcom.com>,
	"Doug Ledford" <dledford@redhat.com>,
	Faisal Latif <faisal.latif@intel.com>,
	"Gal Pressman" <galpress@amazon.com>,
	<GR-everest-linux-l2@marvell.com>,
	"Wei Hu(Xavier)" <huwei87@hisilicon.com>,
	Jakub Kicinski <kuba@kernel.org>,
	"Leon Romanovsky" <leon@kernel.org>, <linux-rdma@vger.kernel.org>,
	Weihang Li <liweihang@huawei.com>,
	Michal Kalderon <mkalderon@marvell.com>,
	"Naresh Kumar PBS" <nareshkumar.pbs@broadcom.com>,
	<netdev@vger.kernel.org>, Lijun Ou <oulijun@huawei.com>,
	VMware PV-Drivers <pv-drivers@vmware.com>,
	"Selvin Xavier" <selvin.xavier@broadcom.com>,
	Yossi Leybovich <sleybo@amazon.com>,
	Somnath Kotur <somnath.kotur@broadcom.com>,
	Sriharsha Basavapatna <sriharsha.basavapatna@broadcom.com>,
	Yishai Hadas <yishaih@nvidia.com>
Cc: Firas JahJah <firasj@amazon.com>,
	Henry Orosco <henry.orosco@intel.com>,
	Leon Romanovsky <leonro@nvidia.com>,
	"Michael J. Ruhl" <michael.j.ruhl@intel.com>,
	Michal Kalderon <michal.kalderon@marvell.com>,
	Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>,
	Shiraz Saleem <shiraz.saleem@intel.com>
Subject: Re: [PATCH v2 00/17] RDMA: Improve use of umem in DMA drivers
Date: Wed, 9 Sep 2020 15:38:48 -0300	[thread overview]
Message-ID: <20200909183848.GA950693@nvidia.com> (raw)
In-Reply-To: <0-v2-270386b7e60b+28f4-umem_1_jgg@nvidia.com>

On Fri, Sep 04, 2020 at 07:41:41PM -0300, Jason Gunthorpe wrote:
> Most RDMA drivers rely on a linear table of DMA addresses organized in
> some device specific page size.
> 
> For a while now the core code has had the rdma_for_each_block() SG
> iterator to help break a umem into DMA blocks for use in the device lists.
> 
> Improve on this by adding rdma_umem_for_each_dma_block(),
> ib_umem_dma_offset() and ib_umem_num_dma_blocks().
> 
> Replace open codings, or calls to fixed PAGE_SIZE APIs, in most of the
> drivers with one of the above APIs.
> 
> Get rid of the really weird and duplicative ib_umem_page_count().
> 
> Fix two problems with ib_umem_find_best_pgsz(), and several problems
> related to computing the wrong DMA list length if IOVA != umem->address.
> 
> At this point many of the driver have a clear path to call
> ib_umem_find_best_pgsz() and replace hardcoded PAGE_SIZE or PAGE_SHIFT
> values when constructing their DMA lists.
> 
> This is the first series in an effort to modernize the umem usage in all
> the DMA drivers.
> 
> v1: https://lore.kernel.org/r/0-v1-00f59ce24f1f+19f50-umem_1_jgg@nvidia.com
> v2:
>  - Fix ib_umem_find_best_pgsz() to use IOVA not umem->addr
>  - Fix ib_umem_num_dma_blocks() to use IOVA not umem->addr
>  - Two new patches to remove wrong open coded versions of
>    ib_umem_num_dma_blocks() from EFA and i40iw
>  - Redo the mlx4 ib_umem_num_dma_blocks() to do less and be safer
>    until the whole thing can be moved to ib_umem_find_best_pgsz()
>  - Two new patches to delete calls to ib_umem_offset() in qedr and
>    ocrdma
> 
> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
> 
> Jason Gunthorpe (17):
>   RDMA/umem: Fix ib_umem_find_best_pgsz() for mappings that cross a page
>     boundary
>   RDMA/umem: Prevent small pages from being returned by
>     ib_umem_find_best_pgsz()
>   RDMA/umem: Use simpler logic for ib_umem_find_best_pgsz()
>   RDMA/umem: Add rdma_umem_for_each_dma_block()
>   RDMA/umem: Replace for_each_sg_dma_page with
>     rdma_umem_for_each_dma_block
>   RDMA/umem: Split ib_umem_num_pages() into ib_umem_num_dma_blocks()
>   RDMA/efa: Use ib_umem_num_dma_pages()
>   RDMA/i40iw: Use ib_umem_num_dma_pages()
>   RDMA/qedr: Use rdma_umem_for_each_dma_block() instead of open-coding
>   RDMA/qedr: Use ib_umem_num_dma_blocks() instead of
>     ib_umem_page_count()
>   RDMA/bnxt: Do not use ib_umem_page_count() or ib_umem_num_pages()
>   RDMA/hns: Use ib_umem_num_dma_blocks() instead of opencoding
>   RDMA/ocrdma: Use ib_umem_num_dma_blocks() instead of
>     ib_umem_page_count()
>   RDMA/pvrdma: Use ib_umem_num_dma_blocks() instead of
>     ib_umem_page_count()
>   RDMA/mlx4: Use ib_umem_num_dma_blocks()
>   RDMA/qedr: Remove fbo and zbva from the MR
>   RDMA/ocrdma: Remove fbo from MR

Applied to for-next with Leon's note. Thanks everyone

Jason