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Date:   Tue, 28 Sep 2021 15:48:48 -0300
From:   Jason Gunthorpe <jgg@ziepe.ca>
To:     Logan Gunthorpe <logang@deltatee.com>
Cc:     linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org,
        linux-block@vger.kernel.org, linux-pci@vger.kernel.org,
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        Stephen Bates <sbates@raithlin.com>,
        Christoph Hellwig <hch@lst.de>,
        Dan Williams <dan.j.williams@intel.com>,
        Christian =?utf-8?B?S8O2bmln?= <christian.koenig@amd.com>,
        John Hubbard <jhubbard@nvidia.com>,
        Don Dutile <ddutile@redhat.com>,
        Matthew Wilcox <willy@infradead.org>,
        Daniel Vetter <daniel.vetter@ffwll.ch>,
        Jakowski Andrzej <andrzej.jakowski@intel.com>,
        Minturn Dave B <dave.b.minturn@intel.com>,
        Jason Ekstrand <jason@jlekstrand.net>,
        Dave Hansen <dave.hansen@linux.intel.com>,
        Xiong Jianxin <jianxin.xiong@intel.com>,
        Bjorn Helgaas <helgaas@kernel.org>,
        Ira Weiny <ira.weiny@intel.com>,
        Robin Murphy <robin.murphy@arm.com>,
        Martin Oliveira <martin.oliveira@eideticom.com>,
        Chaitanya Kulkarni <ckulkarnilinux@gmail.com>
Subject: Re: [PATCH v3 03/20] PCI/P2PDMA: make pci_p2pdma_map_type()
 non-static
Message-ID: <20210928184848.GK3544071@ziepe.ca>
References: <20210916234100.122368-1-logang@deltatee.com>
 <20210916234100.122368-4-logang@deltatee.com>
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On Thu, Sep 16, 2021 at 05:40:43PM -0600, Logan Gunthorpe wrote:
> +enum pci_p2pdma_map_type {
> +	/*
> +	 * PCI_P2PDMA_MAP_UNKNOWN: Used internally for indicating the mapping
> +	 * type hasn't been calculated yet. Functions that return this enum
> +	 * never return this value.
> +	 */
> +	PCI_P2PDMA_MAP_UNKNOWN = 0,
> +
> +	/*
> +	 * PCI_P2PDMA_MAP_NOT_SUPPORTED: Indicates the transaction will
> +	 * traverse the host bridge and the host bridge is not in the
> +	 * whitelist. DMA Mapping routines should return an error when

I gather we are supposed to type allowlist now

> +	 * this is returned.
> +	 */
> +	PCI_P2PDMA_MAP_NOT_SUPPORTED,
> +
> +	/*
> +	 * PCI_P2PDMA_BUS_ADDR: Indicates that two devices can talk to
> +	 * eachother directly through a PCI switch and the transaction will

'each other'

> +	 * not traverse the host bridge. Such a mapping should program
> +	 * the DMA engine with PCI bus addresses.
> +	 */
> +	PCI_P2PDMA_MAP_BUS_ADDR,
> +
> +	/*
> +	 * PCI_P2PDMA_MAP_THRU_HOST_BRIDGE: Indicates two devices can talk
> +	 * to eachother, but the transaction traverses a host bridge on the

'each other'

> +	 * whitelist. In this case, a normal mapping either with CPU physical
> +	 * addresses (in the case of dma-direct) or IOVA addresses (in the
> +	 * case of IOMMUs) should be used to program the DMA engine.
> +	 */
> +	PCI_P2PDMA_MAP_THRU_HOST_BRIDGE,
> +};

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>

Jason