Endpoints have decoders too. It is useful to share the same
infrastructure from cxl_core. Endpoints do not have dports (downstream
targets), only the underlying physical medium. As a result, some special
casing is needed.
There is no functional change introduced yet as endpoints don't actually
enumerate decoders yet.
Signed-off-by: Ben Widawsky <ben.widawsky@xxxxxxxxx>
---
drivers/cxl/core/bus.c | 41 +++++++++++++++++++++++++++++++++--------
1 file changed, 33 insertions(+), 8 deletions(-)
diff --git a/drivers/cxl/core/bus.c b/drivers/cxl/core/bus.c
index 1ee12a60f3f4..16b15f54fb62 100644
--- a/drivers/cxl/core/bus.c
+++ b/drivers/cxl/core/bus.c
@@ -187,6 +187,12 @@ static const struct attribute_group *cxl_decoder_switch_attribute_groups[] = {
NULL,
};
+static const struct attribute_group *cxl_decoder_endpoint_attribute_groups[] = {
+ &cxl_decoder_base_attribute_group,
+ &cxl_base_attribute_group,
+ NULL,
+};
+
static void cxl_decoder_release(struct device *dev)
{
struct cxl_decoder *cxld = to_cxl_decoder(dev);
@@ -196,6 +202,12 @@ static void cxl_decoder_release(struct device *dev)
kfree(cxld);
}
+static const struct device_type cxl_decoder_endpoint_type = {
+ .name = "cxl_decoder_endpoint",
+ .release = cxl_decoder_release,
+ .groups = cxl_decoder_endpoint_attribute_groups,
+};
+
static const struct device_type cxl_decoder_switch_type = {
.name = "cxl_decoder_switch",
.release = cxl_decoder_release,
@@ -208,6 +220,11 @@ static const struct device_type cxl_decoder_root_type = {
.groups = cxl_decoder_root_attribute_groups,
};
+static bool is_endpoint_decoder(struct device *dev)
+{
+ return dev->type == &cxl_decoder_endpoint_type;
+}
+
bool is_root_decoder(struct device *dev)
{
return dev->type == &cxl_decoder_root_type;
@@ -499,7 +516,9 @@ static int decoder_populate_targets(struct cxl_decoder *cxld,
* cxl_decoder_alloc - Allocate a new CXL decoder
* @port: owning port of this decoder
* @nr_targets: downstream targets accessible by this decoder. All upstream
- * ports and root ports must have at least 1 target.
+ * ports and root ports must have at least 1 target. Endpoint
+ * devices will have 0 targets. Callers wishing to register an
+ * endpoint device should specify 0.
*
* A port should contain one or more decoders. Each of those decoders enable
* some address space for CXL.mem utilization. A decoder is expected to be
@@ -516,7 +535,7 @@ struct cxl_decoder *cxl_decoder_alloc(struct cxl_port *port,
struct device *dev;
int rc = 0;
- if (nr_targets > CXL_DECODER_MAX_INTERLEAVE || nr_targets == 0)
+ if (nr_targets > CXL_DECODER_MAX_INTERLEAVE)
return ERR_PTR(-EINVAL);
cxld = kzalloc(struct_size(cxld, target, nr_targets), GFP_KERNEL);
@@ -535,8 +554,11 @@ struct cxl_decoder *cxl_decoder_alloc(struct cxl_port *port,
dev->parent = &port->dev;
dev->bus = &cxl_bus_type;
+ /* Endpoints don't have a target list */
+ if (nr_targets == 0)
+ dev->type = &cxl_decoder_endpoint_type;
/* root ports do not have a cxl_port_type parent */
- if (port->dev.parent->type == &cxl_port_type)
+ else if (port->dev.parent->type == &cxl_port_type)
dev->type = &cxl_decoder_switch_type;
else
dev->type = &cxl_decoder_root_type;
@@ -579,12 +601,15 @@ int cxl_decoder_add(struct cxl_decoder *cxld, int *target_map)
if (cxld->interleave_ways < 1)
return -EINVAL;
- port = to_cxl_port(cxld->dev.parent);
- rc = decoder_populate_targets(cxld, port, target_map);
- if (rc)
- return rc;
-
dev = &cxld->dev;
+
+ port = to_cxl_port(cxld->dev.parent);
+ if (!is_endpoint_decoder(dev)) {
+ rc = decoder_populate_targets(cxld, port, target_map);
+ if (rc)
+ return rc;
+ }
+
rc = dev_set_name(dev, "decoder%d.%d", port->id, cxld->id);
if (rc)
return rc;
--
2.34.0
