diff mbox series

[v2,09/12] cxl/region: Manage decoder target_type at decoder-attach time

Message ID 168679262543.3436160.13053831955768440312.stgit@dwillia2-xfh.jf.intel.com
State Accepted
Commit 8c897b366cda9c7e5ebbb6e8e3da238ecec84535
Headers show
Series Device memory prep | expand

Commit Message

Dan Williams June 15, 2023, 1:30 a.m. UTC 
Switch-level (mid-level) decoders between the platform root and an
endpoint can dynamically switch modes between HDM-H and HDM-D[B]
depending on which region they target. Use the region type to fixup each
decoder that gets allocated to map the given region.

Note that endpoint decoders are meant to determine the region type, so
warn if those ever need to be fixed up, but since it is possible to
continue do so.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 drivers/cxl/core/region.c |   12 ++++++++++++
 1 file changed, 12 insertions(+)
diff mbox series

Patch

diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
index 6a875f86901b..013f3656e661 100644
--- a/drivers/cxl/core/region.c
+++ b/drivers/cxl/core/region.c
@@ -809,6 +809,18 @@  static int cxl_rr_alloc_decoder(struct cxl_port *port, struct cxl_region *cxlr,
 		return -EBUSY;
 	}
 
+	/*
+	 * Endpoints should already match the region type, but backstop that
+	 * assumption with an assertion. Switch-decoders change mapping-type
+	 * based on what is mapped when they are assigned to a region.
+	 */
+	dev_WARN_ONCE(&cxlr->dev,
+		      port == cxled_to_port(cxled) &&
+			      cxld->target_type != cxlr->type,
+		      "%s:%s mismatch decoder type %d -> %d\n",
+		      dev_name(&cxled_to_memdev(cxled)->dev),
+		      dev_name(&cxld->dev), cxld->target_type, cxlr->type);
+	cxld->target_type = cxlr->type;
 	cxl_rr->decoder = cxld;
 	return 0;
 }