On Thu, 23 Jun 2022 19:46:21 -0700
Dan Williams <dan.j.williams@xxxxxxxxx> wrote:
> Previously the target routing specifics of switch decoders and platfom
> CXL window resource tracking of root decoders were factored out of
> 'struct cxl_decoder'. While switch decoders translate from SPA to
> downstream ports, endpoint decoders translate from SPA to DPA.
>
> This patch, 3 of 3, adds a 'struct cxl_endpoint_decoder' that tracks an
> endpoint-specific Device Physical Address (DPA) resource. For now this
> just defines ->dpa_res, a follow-on patch will handle requesting DPA
> resource ranges from a device-DPA resource tree.
>
> Co-developed-by: Ben Widawsky <bwidawsk@xxxxxxxxxx>
> Signed-off-by: Ben Widawsky <bwidawsk@xxxxxxxxxx>
> Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
> ---
> drivers/cxl/core/hdm.c | 12 +++++++++---
> drivers/cxl/core/port.c | 36 +++++++++++++++++++++++++++---------
> drivers/cxl/cxl.h | 15 ++++++++++++++-
> tools/testing/cxl/test/cxl.c | 11 +++++++++--
> 4 files changed, 59 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
> index 6dd1e4c57a67..579f2d802396 100644
> int cxl_decoder_add(struct cxl_decoder *cxld, int *target_map);
> -struct cxl_decoder *cxl_endpoint_decoder_alloc(struct cxl_port *port);
> +struct cxl_endpoint_decoder *cxl_endpoint_decoder_alloc(struct cxl_port *port);
> int cxl_decoder_add_locked(struct cxl_decoder *cxld, int *target_map);
> int cxl_decoder_autoremove(struct device *host, struct cxl_decoder *cxld);
> int cxl_endpoint_autoremove(struct cxl_memdev *cxlmd, struct cxl_port *endpoint);
> diff --git a/tools/testing/cxl/test/cxl.c b/tools/testing/cxl/test/cxl.c
> index 68288354b419..f52a5dd69d36 100644
> --- a/tools/testing/cxl/test/cxl.c
> +++ b/tools/testing/cxl/test/cxl.c
> @@ -459,8 +459,15 @@ static int mock_cxl_enumerate_decoders(struct cxl_hdm *cxlhdm)
> cxld = ERR_CAST(cxlsd);
> else
> cxld = &cxlsd->cxld;
> - } else
> - cxld = cxl_endpoint_decoder_alloc(port);
> + } else {
> + struct cxl_endpoint_decoder *cxled;
> +
> + cxled = cxl_endpoint_decoder_alloc(port);
> + if (IS_ERR(cxled))
> + cxld = ERR_CAST(cxled);
It's my favourite code pattern to moan about today :)
Same thing - just handle error here and it'll be easier to read for cost of a few
lines of additional code. Few other cases of it in here.
> + else
> + cxld = &cxled->cxld;
> + }
> if (IS_ERR(cxld)) {
> dev_warn(&port->dev,
> "Failed to allocate the decoder\n");
>
