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Diffstat (limited to 'drivers/cxl/core/pmem.c')
-rw-r--r--drivers/cxl/core/pmem.c285
1 files changed, 285 insertions, 0 deletions
diff --git a/drivers/cxl/core/pmem.c b/drivers/cxl/core/pmem.c
new file mode 100644
index 000000000..36aa5070d
--- /dev/null
+++ b/drivers/cxl/core/pmem.c
@@ -0,0 +1,285 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright(c) 2020 Intel Corporation. */
+#include <linux/device.h>
+#include <linux/slab.h>
+#include <linux/idr.h>
+#include <cxlmem.h>
+#include <cxl.h>
+#include "core.h"
+
+/**
+ * DOC: cxl pmem
+ *
+ * The core CXL PMEM infrastructure supports persistent memory
+ * provisioning and serves as a bridge to the LIBNVDIMM subsystem. A CXL
+ * 'bridge' device is added at the root of a CXL device topology if
+ * platform firmware advertises at least one persistent memory capable
+ * CXL window. That root-level bridge corresponds to a LIBNVDIMM 'bus'
+ * device. Then for each cxl_memdev in the CXL device topology a bridge
+ * device is added to host a LIBNVDIMM dimm object. When these bridges
+ * are registered native LIBNVDIMM uapis are translated to CXL
+ * operations, for example, namespace label access commands.
+ */
+
+static DEFINE_IDA(cxl_nvdimm_bridge_ida);
+
+static void cxl_nvdimm_bridge_release(struct device *dev)
+{
+ struct cxl_nvdimm_bridge *cxl_nvb = to_cxl_nvdimm_bridge(dev);
+
+ ida_free(&cxl_nvdimm_bridge_ida, cxl_nvb->id);
+ kfree(cxl_nvb);
+}
+
+static const struct attribute_group *cxl_nvdimm_bridge_attribute_groups[] = {
+ &cxl_base_attribute_group,
+ NULL,
+};
+
+const struct device_type cxl_nvdimm_bridge_type = {
+ .name = "cxl_nvdimm_bridge",
+ .release = cxl_nvdimm_bridge_release,
+ .groups = cxl_nvdimm_bridge_attribute_groups,
+};
+
+struct cxl_nvdimm_bridge *to_cxl_nvdimm_bridge(struct device *dev)
+{
+ if (dev_WARN_ONCE(dev, dev->type != &cxl_nvdimm_bridge_type,
+ "not a cxl_nvdimm_bridge device\n"))
+ return NULL;
+ return container_of(dev, struct cxl_nvdimm_bridge, dev);
+}
+EXPORT_SYMBOL_NS_GPL(to_cxl_nvdimm_bridge, CXL);
+
+bool is_cxl_nvdimm_bridge(struct device *dev)
+{
+ return dev->type == &cxl_nvdimm_bridge_type;
+}
+EXPORT_SYMBOL_NS_GPL(is_cxl_nvdimm_bridge, CXL);
+
+static int match_nvdimm_bridge(struct device *dev, void *data)
+{
+ return is_cxl_nvdimm_bridge(dev);
+}
+
+struct cxl_nvdimm_bridge *cxl_find_nvdimm_bridge(struct device *start)
+{
+ struct cxl_port *port = find_cxl_root(start);
+ struct device *dev;
+
+ if (!port)
+ return NULL;
+
+ dev = device_find_child(&port->dev, NULL, match_nvdimm_bridge);
+ put_device(&port->dev);
+
+ if (!dev)
+ return NULL;
+
+ return to_cxl_nvdimm_bridge(dev);
+}
+EXPORT_SYMBOL_NS_GPL(cxl_find_nvdimm_bridge, CXL);
+
+static struct lock_class_key cxl_nvdimm_bridge_key;
+
+static struct cxl_nvdimm_bridge *cxl_nvdimm_bridge_alloc(struct cxl_port *port)
+{
+ struct cxl_nvdimm_bridge *cxl_nvb;
+ struct device *dev;
+ int rc;
+
+ cxl_nvb = kzalloc(sizeof(*cxl_nvb), GFP_KERNEL);
+ if (!cxl_nvb)
+ return ERR_PTR(-ENOMEM);
+
+ rc = ida_alloc(&cxl_nvdimm_bridge_ida, GFP_KERNEL);
+ if (rc < 0)
+ goto err;
+ cxl_nvb->id = rc;
+
+ dev = &cxl_nvb->dev;
+ cxl_nvb->port = port;
+ cxl_nvb->state = CXL_NVB_NEW;
+ device_initialize(dev);
+ lockdep_set_class(&dev->mutex, &cxl_nvdimm_bridge_key);
+ device_set_pm_not_required(dev);
+ dev->parent = &port->dev;
+ dev->bus = &cxl_bus_type;
+ dev->type = &cxl_nvdimm_bridge_type;
+
+ return cxl_nvb;
+
+err:
+ kfree(cxl_nvb);
+ return ERR_PTR(rc);
+}
+
+static void unregister_nvb(void *_cxl_nvb)
+{
+ struct cxl_nvdimm_bridge *cxl_nvb = _cxl_nvb;
+ bool flush;
+
+ /*
+ * If the bridge was ever activated then there might be in-flight state
+ * work to flush. Once the state has been changed to 'dead' then no new
+ * work can be queued by user-triggered bind.
+ */
+ device_lock(&cxl_nvb->dev);
+ flush = cxl_nvb->state != CXL_NVB_NEW;
+ cxl_nvb->state = CXL_NVB_DEAD;
+ device_unlock(&cxl_nvb->dev);
+
+ /*
+ * Even though the device core will trigger device_release_driver()
+ * before the unregister, it does not know about the fact that
+ * cxl_nvdimm_bridge_driver defers ->remove() work. So, do the driver
+ * release not and flush it before tearing down the nvdimm device
+ * hierarchy.
+ */
+ device_release_driver(&cxl_nvb->dev);
+ if (flush)
+ flush_work(&cxl_nvb->state_work);
+ device_unregister(&cxl_nvb->dev);
+}
+
+/**
+ * devm_cxl_add_nvdimm_bridge() - add the root of a LIBNVDIMM topology
+ * @host: platform firmware root device
+ * @port: CXL port at the root of a CXL topology
+ *
+ * Return: bridge device that can host cxl_nvdimm objects
+ */
+struct cxl_nvdimm_bridge *devm_cxl_add_nvdimm_bridge(struct device *host,
+ struct cxl_port *port)
+{
+ struct cxl_nvdimm_bridge *cxl_nvb;
+ struct device *dev;
+ int rc;
+
+ if (!IS_ENABLED(CONFIG_CXL_PMEM))
+ return ERR_PTR(-ENXIO);
+
+ cxl_nvb = cxl_nvdimm_bridge_alloc(port);
+ if (IS_ERR(cxl_nvb))
+ return cxl_nvb;
+
+ dev = &cxl_nvb->dev;
+ rc = dev_set_name(dev, "nvdimm-bridge%d", cxl_nvb->id);
+ if (rc)
+ goto err;
+
+ rc = device_add(dev);
+ if (rc)
+ goto err;
+
+ rc = devm_add_action_or_reset(host, unregister_nvb, cxl_nvb);
+ if (rc)
+ return ERR_PTR(rc);
+
+ return cxl_nvb;
+
+err:
+ put_device(dev);
+ return ERR_PTR(rc);
+}
+EXPORT_SYMBOL_NS_GPL(devm_cxl_add_nvdimm_bridge, CXL);
+
+static void cxl_nvdimm_release(struct device *dev)
+{
+ struct cxl_nvdimm *cxl_nvd = to_cxl_nvdimm(dev);
+
+ xa_destroy(&cxl_nvd->pmem_regions);
+ kfree(cxl_nvd);
+}
+
+static const struct attribute_group *cxl_nvdimm_attribute_groups[] = {
+ &cxl_base_attribute_group,
+ NULL,
+};
+
+const struct device_type cxl_nvdimm_type = {
+ .name = "cxl_nvdimm",
+ .release = cxl_nvdimm_release,
+ .groups = cxl_nvdimm_attribute_groups,
+};
+
+bool is_cxl_nvdimm(struct device *dev)
+{
+ return dev->type == &cxl_nvdimm_type;
+}
+EXPORT_SYMBOL_NS_GPL(is_cxl_nvdimm, CXL);
+
+struct cxl_nvdimm *to_cxl_nvdimm(struct device *dev)
+{
+ if (dev_WARN_ONCE(dev, !is_cxl_nvdimm(dev),
+ "not a cxl_nvdimm device\n"))
+ return NULL;
+ return container_of(dev, struct cxl_nvdimm, dev);
+}
+EXPORT_SYMBOL_NS_GPL(to_cxl_nvdimm, CXL);
+
+static struct lock_class_key cxl_nvdimm_key;
+
+static struct cxl_nvdimm *cxl_nvdimm_alloc(struct cxl_memdev *cxlmd)
+{
+ struct cxl_nvdimm *cxl_nvd;
+ struct device *dev;
+
+ cxl_nvd = kzalloc(sizeof(*cxl_nvd), GFP_KERNEL);
+ if (!cxl_nvd)
+ return ERR_PTR(-ENOMEM);
+
+ dev = &cxl_nvd->dev;
+ cxl_nvd->cxlmd = cxlmd;
+ xa_init(&cxl_nvd->pmem_regions);
+ device_initialize(dev);
+ lockdep_set_class(&dev->mutex, &cxl_nvdimm_key);
+ device_set_pm_not_required(dev);
+ dev->parent = &cxlmd->dev;
+ dev->bus = &cxl_bus_type;
+ dev->type = &cxl_nvdimm_type;
+
+ return cxl_nvd;
+}
+
+static void cxl_nvd_unregister(void *dev)
+{
+ device_unregister(dev);
+}
+
+/**
+ * devm_cxl_add_nvdimm() - add a bridge between a cxl_memdev and an nvdimm
+ * @host: same host as @cxlmd
+ * @cxlmd: cxl_memdev instance that will perform LIBNVDIMM operations
+ *
+ * Return: 0 on success negative error code on failure.
+ */
+int devm_cxl_add_nvdimm(struct device *host, struct cxl_memdev *cxlmd)
+{
+ struct cxl_nvdimm *cxl_nvd;
+ struct device *dev;
+ int rc;
+
+ cxl_nvd = cxl_nvdimm_alloc(cxlmd);
+ if (IS_ERR(cxl_nvd))
+ return PTR_ERR(cxl_nvd);
+
+ dev = &cxl_nvd->dev;
+ rc = dev_set_name(dev, "pmem%d", cxlmd->id);
+ if (rc)
+ goto err;
+
+ rc = device_add(dev);
+ if (rc)
+ goto err;
+
+ dev_dbg(host, "%s: register %s\n", dev_name(dev->parent),
+ dev_name(dev));
+
+ return devm_add_action_or_reset(host, cxl_nvd_unregister, dev);
+
+err:
+ put_device(dev);
+ return rc;
+}
+EXPORT_SYMBOL_NS_GPL(devm_cxl_add_nvdimm, CXL);