| Message ID | 20250211095349.981096-10-rrichter@amd.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | cxl: Address translation support, part 1: Cleanups and refactoring | expand |
On 2/11/25 2:53 AM, Robert Richter wrote: > In function cxl_add_to_region() there is code to determine the root > decoder associated to an endpoint decoder. Factor out that code for > later reuse. This has the benefit of reducing cxl_add_to_region()'s > function complexity. > > The reference of cxlrd_dev can be freed earlier. Since the root > decoder exists as long as the root port exists and the endpoint > already holds a reference to the root port, this additional reference > is not needed. Though it looks obvious to use __free() for the > reference of cxlrd_dev here too, this is done in a later rework. So > just move the code. > > Signed-off-by: Robert Richter <rrichter@amd.com> > Reviewed-by: Gregory Price <gourry@gourry.net> > Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> > Tested-by: Gregory Price <gourry@gourry.net> Reviewed-by: Dave Jiang <dave.jiang@intel.com> > --- > drivers/cxl/core/region.c | 55 ++++++++++++++++++++++++++------------- > 1 file changed, 37 insertions(+), 18 deletions(-) > > diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c > index 0e38bcb43be6..c641c8922455 100644 > --- a/drivers/cxl/core/region.c > +++ b/drivers/cxl/core/region.c > @@ -3203,6 +3203,38 @@ static int match_root_decoder_by_range(struct device *dev, > return range_contains(r1, r2); > } > > +static struct cxl_root_decoder * > +cxl_find_root_decoder(struct cxl_endpoint_decoder *cxled) > +{ > + struct cxl_memdev *cxlmd = cxled_to_memdev(cxled); > + struct cxl_port *port = cxled_to_port(cxled); > + struct cxl_root *cxl_root __free(put_cxl_root) = find_cxl_root(port); > + struct cxl_decoder *cxld = &cxled->cxld; > + struct range *hpa = &cxld->hpa_range; > + struct device *cxlrd_dev; > + > + cxlrd_dev = device_find_child(&cxl_root->port.dev, hpa, > + match_root_decoder_by_range); > + if (!cxlrd_dev) { > + dev_err(cxlmd->dev.parent, > + "%s:%s no CXL window for range %#llx:%#llx\n", > + dev_name(&cxlmd->dev), dev_name(&cxld->dev), > + cxld->hpa_range.start, cxld->hpa_range.end); > + return NULL; > + } > + > + /* > + * device_find_child() created a reference to the root > + * decoder. Since the root decoder exists as long as the root > + * port exists and the endpoint already holds a reference to > + * the root port, this additional reference is not needed. > + * Free it here. > + */ > + put_device(cxlrd_dev); > + > + return to_cxl_root_decoder(cxlrd_dev); > +} > + > static int match_region_by_range(struct device *dev, const void *data) > { > struct cxl_region_params *p; > @@ -3314,29 +3346,17 @@ static struct cxl_region *construct_region(struct cxl_root_decoder *cxlrd, > > int cxl_add_to_region(struct cxl_endpoint_decoder *cxled) > { > - struct cxl_memdev *cxlmd = cxled_to_memdev(cxled); > - struct cxl_port *port = cxled_to_port(cxled); > - struct cxl_root *cxl_root __free(put_cxl_root) = find_cxl_root(port); > struct range *hpa = &cxled->cxld.hpa_range; > - struct cxl_decoder *cxld = &cxled->cxld; > - struct device *cxlrd_dev, *region_dev; > + struct device *region_dev; > struct cxl_root_decoder *cxlrd; > struct cxl_region_params *p; > struct cxl_region *cxlr; > bool attach = false; > int rc; > > - cxlrd_dev = device_find_child(&cxl_root->port.dev, &cxld->hpa_range, > - match_root_decoder_by_range); > - if (!cxlrd_dev) { > - dev_err(cxlmd->dev.parent, > - "%s:%s no CXL window for range %#llx:%#llx\n", > - dev_name(&cxlmd->dev), dev_name(&cxld->dev), > - cxld->hpa_range.start, cxld->hpa_range.end); > + cxlrd = cxl_find_root_decoder(cxled); > + if (!cxlrd) > return -ENXIO; > - } > - > - cxlrd = to_cxl_root_decoder(cxlrd_dev); > > /* > * Ensure that if multiple threads race to construct_region() for @hpa > @@ -3354,7 +3374,7 @@ int cxl_add_to_region(struct cxl_endpoint_decoder *cxled) > > rc = PTR_ERR_OR_ZERO(cxlr); > if (rc) > - goto out; > + return rc; > > attach_target(cxlr, cxled, -1, TASK_UNINTERRUPTIBLE); > > @@ -3375,8 +3395,7 @@ int cxl_add_to_region(struct cxl_endpoint_decoder *cxled) > } > > put_device(region_dev); > -out: > - put_device(cxlrd_dev); > + > return rc; > } > EXPORT_SYMBOL_NS_GPL(cxl_add_to_region, "CXL");
diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c index 0e38bcb43be6..c641c8922455 100644 --- a/drivers/cxl/core/region.c +++ b/drivers/cxl/core/region.c @@ -3203,6 +3203,38 @@ static int match_root_decoder_by_range(struct device *dev, return range_contains(r1, r2); } +static struct cxl_root_decoder * +cxl_find_root_decoder(struct cxl_endpoint_decoder *cxled) +{ + struct cxl_memdev *cxlmd = cxled_to_memdev(cxled); + struct cxl_port *port = cxled_to_port(cxled); + struct cxl_root *cxl_root __free(put_cxl_root) = find_cxl_root(port); + struct cxl_decoder *cxld = &cxled->cxld; + struct range *hpa = &cxld->hpa_range; + struct device *cxlrd_dev; + + cxlrd_dev = device_find_child(&cxl_root->port.dev, hpa, + match_root_decoder_by_range); + if (!cxlrd_dev) { + dev_err(cxlmd->dev.parent, + "%s:%s no CXL window for range %#llx:%#llx\n", + dev_name(&cxlmd->dev), dev_name(&cxld->dev), + cxld->hpa_range.start, cxld->hpa_range.end); + return NULL; + } + + /* + * device_find_child() created a reference to the root + * decoder. Since the root decoder exists as long as the root + * port exists and the endpoint already holds a reference to + * the root port, this additional reference is not needed. + * Free it here. + */ + put_device(cxlrd_dev); + + return to_cxl_root_decoder(cxlrd_dev); +} + static int match_region_by_range(struct device *dev, const void *data) { struct cxl_region_params *p; @@ -3314,29 +3346,17 @@ static struct cxl_region *construct_region(struct cxl_root_decoder *cxlrd, int cxl_add_to_region(struct cxl_endpoint_decoder *cxled) { - struct cxl_memdev *cxlmd = cxled_to_memdev(cxled); - struct cxl_port *port = cxled_to_port(cxled); - struct cxl_root *cxl_root __free(put_cxl_root) = find_cxl_root(port); struct range *hpa = &cxled->cxld.hpa_range; - struct cxl_decoder *cxld = &cxled->cxld; - struct device *cxlrd_dev, *region_dev; + struct device *region_dev; struct cxl_root_decoder *cxlrd; struct cxl_region_params *p; struct cxl_region *cxlr; bool attach = false; int rc; - cxlrd_dev = device_find_child(&cxl_root->port.dev, &cxld->hpa_range, - match_root_decoder_by_range); - if (!cxlrd_dev) { - dev_err(cxlmd->dev.parent, - "%s:%s no CXL window for range %#llx:%#llx\n", - dev_name(&cxlmd->dev), dev_name(&cxld->dev), - cxld->hpa_range.start, cxld->hpa_range.end); + cxlrd = cxl_find_root_decoder(cxled); + if (!cxlrd) return -ENXIO; - } - - cxlrd = to_cxl_root_decoder(cxlrd_dev); /* * Ensure that if multiple threads race to construct_region() for @hpa @@ -3354,7 +3374,7 @@ int cxl_add_to_region(struct cxl_endpoint_decoder *cxled) rc = PTR_ERR_OR_ZERO(cxlr); if (rc) - goto out; + return rc; attach_target(cxlr, cxled, -1, TASK_UNINTERRUPTIBLE); @@ -3375,8 +3395,7 @@ int cxl_add_to_region(struct cxl_endpoint_decoder *cxled) } put_device(region_dev); -out: - put_device(cxlrd_dev); + return rc; } EXPORT_SYMBOL_NS_GPL(cxl_add_to_region, "CXL");