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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.c113
1 files changed, 85 insertions, 28 deletions
diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
index 401148016978..f9ae5ad284ff 100644
--- a/drivers/cxl/core/region.c
+++ b/drivers/cxl/core/region.c
@@ -174,7 +174,8 @@ static int cxl_region_decode_commit(struct cxl_region *cxlr)
iter = to_cxl_port(iter->dev.parent)) {
cxl_rr = cxl_rr_load(iter, cxlr);
cxld = cxl_rr->decoder;
- rc = cxld->commit(cxld);
+ if (cxld->commit)
+ rc = cxld->commit(cxld);
if (rc)
break;
}
@@ -657,6 +658,9 @@ 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)
+ continue;
+
if (ip->res->start > p->res->start) {
dev_dbg(&cxlr->dev,
"%s: HPA order violation %s:%pr vs %pr\n",
@@ -686,18 +690,27 @@ static struct cxl_region_ref *alloc_region_ref(struct cxl_port *port,
return cxl_rr;
}
-static void free_region_ref(struct cxl_region_ref *cxl_rr)
+static void cxl_rr_free_decoder(struct cxl_region_ref *cxl_rr)
{
- struct cxl_port *port = cxl_rr->port;
struct cxl_region *cxlr = cxl_rr->region;
struct cxl_decoder *cxld = cxl_rr->decoder;
+ if (!cxld)
+ return;
+
dev_WARN_ONCE(&cxlr->dev, cxld->region != cxlr, "region mismatch\n");
if (cxld->region == cxlr) {
cxld->region = NULL;
put_device(&cxlr->dev);
}
+}
+static void free_region_ref(struct cxl_region_ref *cxl_rr)
+{
+ struct cxl_port *port = cxl_rr->port;
+ struct cxl_region *cxlr = cxl_rr->region;
+
+ cxl_rr_free_decoder(cxl_rr);
xa_erase(&port->regions, (unsigned long)cxlr);
xa_destroy(&cxl_rr->endpoints);
kfree(cxl_rr);
@@ -728,6 +741,33 @@ static int cxl_rr_ep_add(struct cxl_region_ref *cxl_rr,
return 0;
}
+static int cxl_rr_alloc_decoder(struct cxl_port *port, struct cxl_region *cxlr,
+ struct cxl_endpoint_decoder *cxled,
+ struct cxl_region_ref *cxl_rr)
+{
+ struct cxl_decoder *cxld;
+
+ if (port == cxled_to_port(cxled))
+ cxld = &cxled->cxld;
+ else
+ cxld = cxl_region_find_decoder(port, cxlr);
+ if (!cxld) {
+ dev_dbg(&cxlr->dev, "%s: no decoder available\n",
+ dev_name(&port->dev));
+ return -EBUSY;
+ }
+
+ if (cxld->region) {
+ dev_dbg(&cxlr->dev, "%s: %s already attached to %s\n",
+ dev_name(&port->dev), dev_name(&cxld->dev),
+ dev_name(&cxld->region->dev));
+ return -EBUSY;
+ }
+
+ cxl_rr->decoder = cxld;
+ return 0;
+}
+
/**
* cxl_port_attach_region() - track a region's interest in a port by endpoint
* @port: port to add a new region reference 'struct cxl_region_ref'
@@ -794,12 +834,6 @@ static int cxl_port_attach_region(struct cxl_port *port,
cxl_rr->nr_targets++;
nr_targets_inc = true;
}
-
- /*
- * The decoder for @cxlr was allocated when the region was first
- * attached to @port.
- */
- cxld = cxl_rr->decoder;
} else {
cxl_rr = alloc_region_ref(port, cxlr);
if (IS_ERR(cxl_rr)) {
@@ -810,26 +844,11 @@ static int cxl_port_attach_region(struct cxl_port *port,
}
nr_targets_inc = true;
- if (port == cxled_to_port(cxled))
- cxld = &cxled->cxld;
- else
- cxld = cxl_region_find_decoder(port, cxlr);
- if (!cxld) {
- dev_dbg(&cxlr->dev, "%s: no decoder available\n",
- dev_name(&port->dev));
- goto out_erase;
- }
-
- if (cxld->region) {
- dev_dbg(&cxlr->dev, "%s: %s already attached to %s\n",
- dev_name(&port->dev), dev_name(&cxld->dev),
- dev_name(&cxld->region->dev));
- rc = -EBUSY;
+ rc = cxl_rr_alloc_decoder(port, cxlr, cxled, cxl_rr);
+ if (rc)
goto out_erase;
- }
-
- cxl_rr->decoder = cxld;
}
+ cxld = cxl_rr->decoder;
rc = cxl_rr_ep_add(cxl_rr, cxled);
if (rc) {
@@ -971,7 +990,14 @@ static int cxl_port_setup_targets(struct cxl_port *port,
if (cxl_rr->nr_targets_set) {
int i, distance;
- distance = p->nr_targets / cxl_rr->nr_targets;
+ /*
+ * Passthrough ports impose no distance requirements between
+ * peers
+ */
+ if (port->nr_dports == 1)
+ distance = 0;
+ else
+ distance = p->nr_targets / cxl_rr->nr_targets;
for (i = 0; i < cxl_rr->nr_targets_set; i++)
if (ep->dport == cxlsd->target[i]) {
rc = check_last_peer(cxled, ep, cxl_rr,
@@ -1508,9 +1534,24 @@ static const struct attribute_group *region_groups[] = {
static void cxl_region_release(struct device *dev)
{
+ struct cxl_root_decoder *cxlrd = to_cxl_root_decoder(dev->parent);
struct cxl_region *cxlr = to_cxl_region(dev);
+ int id = atomic_read(&cxlrd->region_id);
+
+ /*
+ * Try to reuse the recently idled id rather than the cached
+ * next id to prevent the region id space from increasing
+ * unnecessarily.
+ */
+ if (cxlr->id < id)
+ if (atomic_try_cmpxchg(&cxlrd->region_id, &id, cxlr->id)) {
+ memregion_free(id);
+ goto out;
+ }
memregion_free(cxlr->id);
+out:
+ put_device(dev->parent);
kfree(cxlr);
}
@@ -1538,8 +1579,19 @@ static struct cxl_region *to_cxl_region(struct device *dev)
static void unregister_region(void *dev)
{
struct cxl_region *cxlr = to_cxl_region(dev);
+ struct cxl_region_params *p = &cxlr->params;
+ int i;
device_del(dev);
+
+ /*
+ * Now that region sysfs is shutdown, the parameter block is now
+ * read-only, so no need to hold the region rwsem to access the
+ * region parameters.
+ */
+ for (i = 0; i < p->interleave_ways; i++)
+ detach_target(cxlr, i);
+
cxl_region_iomem_release(cxlr);
put_device(dev);
}
@@ -1561,6 +1613,11 @@ static struct cxl_region *cxl_region_alloc(struct cxl_root_decoder *cxlrd, int i
device_initialize(dev);
lockdep_set_class(&dev->mutex, &cxl_region_key);
dev->parent = &cxlrd->cxlsd.cxld.dev;
+ /*
+ * Keep root decoder pinned through cxl_region_release to fixup
+ * region id allocations
+ */
+ get_device(dev->parent);
device_set_pm_not_required(dev);
dev->bus = &cxl_bus_type;
dev->type = &cxl_region_type;