Re: [PATCH v2 5/8] PCI/IDE: Initialize an ID for all IDE streams

[Jonathan Cameron <jonathan.cameron@huawei.com>]

On Wed, 12 Nov 2025 18:14:43 -0800
Dan Williams <dan.j.williams@intel.com> wrote:

> The PCIe spec defines two types of streams - selective and link.  Each
> stream has an ID from the same bucket so a stream ID does not tell the
> type.  The spec defines an "enable" bit for every stream and required
> stream IDs to be unique among all enabled stream but there is no such
> requirement for disabled streams.
> 
> However, when IDE_KM is programming keys, an IDE-capable device needs
> to know the type of stream being programmed to write it directly to
> the hardware as keys are relatively large, possibly many of them and
> devices often struggle with keeping around rather big data not being
> used.
> 
> Walk through all streams on a device and initialise the IDs to some
> unique number, both link and selective.
> 
> The weakest part of this proposal is the host bridge ide_stream_ids_ida.
> Technically, a Stream ID only needs to be unique within a given partner
> pair. However, with "anonymous" / unassigned streams there is no convenient
> place to track the available ids. Proceed with an ida in the host bridge
> for now, but consider moving this tracking to be an ide_stream_ids_ida per
> device.
> 
> Co-developed-by: Alexey Kardashevskiy <aik@amd.com>
> Signed-off-by: Alexey Kardashevskiy <aik@amd.com>
> Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>