Re: [PATCH v9 02/24] dma-mapping: move the PCI P2PDMA mapping helpers to pci-p2pdma.h

[Luis Chamberlain]

On Wed, Apr 23, 2025 at 11:12:53AM +0300, Leon Romanovsky wrote:
> From: Christoph Hellwig <hch@xxxxxx>
> +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.
> +	 */

This last sentence is confusing. How about:

* PCI_P2PDMA_MAP_UNKNOWN: Used internally as an initial state before
* the mapping type has been calculated. Exported routines for the API
* will never return this value.

> +	PCI_P2PDMA_MAP_UNKNOWN = 0,
> +
> +	/*
> +	 * Not a PCI P2PDMA transfer.
> +	 */
> +	PCI_P2PDMA_MAP_NONE,
> +
> +	/*
> +	 * PCI_P2PDMA_MAP_NOT_SUPPORTED: Indicates the transaction will
> +	 * traverse the host bridge and the host bridge is not in the
> +	 * allowlist. DMA Mapping routines should return an error when
> +	 * this is returned.
> +	 */
> +	PCI_P2PDMA_MAP_NOT_SUPPORTED,
> +
> +	/*
> +	 * PCI_P2PDMA_BUS_ADDR: Indicates that two devices can talk to

You mean   PCI_P2PDMA_MAP_BUS_ADDR

> + * pci_p2pdma_bus_addr_map - map a PCI_P2PDMA_MAP_BUS_ADDR P2P transfer

Hrm, maybe with a bit more clarity:

Translate a physical address to a bus address for a  PCI_P2PDMA_MAP_BUS_ADDR
transfer.


Other than that.

Reviewed-by: Luis Chamberlain <mcgrof@xxxxxxxxxx>

  Luis