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path: root/drivers/cxl/core/region.c
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Diffstat (limited to 'drivers/cxl/core/region.c')
-rw-r--r--drivers/cxl/core/region.c62
1 files changed, 46 insertions, 16 deletions
diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
index ce0e2d82bb2b..4c7fd2d5cccb 100644
--- a/drivers/cxl/core/region.c
+++ b/drivers/cxl/core/region.c
@@ -730,12 +730,17 @@ static int match_auto_decoder(struct device *dev, void *data)
return 0;
}
-static struct cxl_decoder *cxl_region_find_decoder(struct cxl_port *port,
- struct cxl_region *cxlr)
+static struct cxl_decoder *
+cxl_region_find_decoder(struct cxl_port *port,
+ struct cxl_endpoint_decoder *cxled,
+ struct cxl_region *cxlr)
{
struct device *dev;
int id = 0;
+ if (port == cxled_to_port(cxled))
+ return &cxled->cxld;
+
if (test_bit(CXL_REGION_F_AUTO, &cxlr->flags))
dev = device_find_child(&port->dev, &cxlr->params,
match_auto_decoder);
@@ -753,8 +758,31 @@ static struct cxl_decoder *cxl_region_find_decoder(struct cxl_port *port,
return to_cxl_decoder(dev);
}
-static struct cxl_region_ref *alloc_region_ref(struct cxl_port *port,
- struct cxl_region *cxlr)
+static bool auto_order_ok(struct cxl_port *port, struct cxl_region *cxlr_iter,
+ struct cxl_decoder *cxld)
+{
+ struct cxl_region_ref *rr = cxl_rr_load(port, cxlr_iter);
+ struct cxl_decoder *cxld_iter = rr->decoder;
+
+ /*
+ * Allow the out of order assembly of auto-discovered regions.
+ * Per CXL Spec 3.1 8.2.4.20.12 software must commit decoders
+ * in HPA order. Confirm that the decoder with the lesser HPA
+ * starting address has the lesser id.
+ */
+ dev_dbg(&cxld->dev, "check for HPA violation %s:%d < %s:%d\n",
+ dev_name(&cxld->dev), cxld->id,
+ dev_name(&cxld_iter->dev), cxld_iter->id);
+
+ if (cxld_iter->id > cxld->id)
+ return true;
+
+ return false;
+}
+
+static struct cxl_region_ref *
+alloc_region_ref(struct cxl_port *port, struct cxl_region *cxlr,
+ struct cxl_endpoint_decoder *cxled)
{
struct cxl_region_params *p = &cxlr->params;
struct cxl_region_ref *cxl_rr, *iter;
@@ -764,16 +792,21 @@ static struct cxl_region_ref *alloc_region_ref(struct cxl_port *port,
xa_for_each(&port->regions, index, iter) {
struct cxl_region_params *ip = &iter->region->params;
- if (!ip->res)
+ if (!ip->res || ip->res->start < p->res->start)
continue;
- if (ip->res->start > p->res->start) {
- dev_dbg(&cxlr->dev,
- "%s: HPA order violation %s:%pr vs %pr\n",
- dev_name(&port->dev),
- dev_name(&iter->region->dev), ip->res, p->res);
- return ERR_PTR(-EBUSY);
+ if (test_bit(CXL_REGION_F_AUTO, &cxlr->flags)) {
+ struct cxl_decoder *cxld;
+
+ cxld = cxl_region_find_decoder(port, cxled, cxlr);
+ if (auto_order_ok(port, iter->region, cxld))
+ continue;
}
+ dev_dbg(&cxlr->dev, "%s: HPA order violation %s:%pr vs %pr\n",
+ dev_name(&port->dev),
+ dev_name(&iter->region->dev), ip->res, p->res);
+
+ return ERR_PTR(-EBUSY);
}
cxl_rr = kzalloc(sizeof(*cxl_rr), GFP_KERNEL);
@@ -853,10 +886,7 @@ static int cxl_rr_alloc_decoder(struct cxl_port *port, struct cxl_region *cxlr,
{
struct cxl_decoder *cxld;
- if (port == cxled_to_port(cxled))
- cxld = &cxled->cxld;
- else
- cxld = cxl_region_find_decoder(port, cxlr);
+ cxld = cxl_region_find_decoder(port, cxled, cxlr);
if (!cxld) {
dev_dbg(&cxlr->dev, "%s: no decoder available\n",
dev_name(&port->dev));
@@ -953,7 +983,7 @@ static int cxl_port_attach_region(struct cxl_port *port,
nr_targets_inc = true;
}
} else {
- cxl_rr = alloc_region_ref(port, cxlr);
+ cxl_rr = alloc_region_ref(port, cxlr, cxled);
if (IS_ERR(cxl_rr)) {
dev_dbg(&cxlr->dev,
"%s: failed to allocate region reference\n",