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authorDan Williams <dan.j.williams@intel.com>2017-07-16 23:51:53 +0300
committerDan Williams <dan.j.williams@intel.com>2019-01-07 08:41:57 +0300
commit730926c3b0998943654019f00296cf8e3b02277e (patch)
tree9bdff0b62f4a020427144de5b703048bfb1f7c16 /drivers/dax/pmem
parentd200781ef237a354d918ceff5cee350d88a93d42 (diff)
downloadlinux-730926c3b0998943654019f00296cf8e3b02277e.tar.xz
device-dax: Add /sys/class/dax backwards compatibility
On the expectation that some environments may not upgrade libdaxctl (userspace component that depends on the /sys/class/dax hierarchy), provide a default / legacy dax_pmem_compat driver. The dax_pmem_compat driver implements the original /sys/class/dax sysfs layout rather than /sys/bus/dax. When userspace is upgraded it can blacklist this module and switch to the dax_pmem driver going forward. CONFIG_DEV_DAX_PMEM_COMPAT and supporting code will be deleted according to the dax_pmem entry in Documentation/ABI/obsolete/. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers/dax/pmem')
-rw-r--r--drivers/dax/pmem/Makefile7
-rw-r--r--drivers/dax/pmem/compat.c73
-rw-r--r--drivers/dax/pmem/core.c69
-rw-r--r--drivers/dax/pmem/pmem.c40
4 files changed, 189 insertions, 0 deletions
diff --git a/drivers/dax/pmem/Makefile b/drivers/dax/pmem/Makefile
new file mode 100644
index 000000000000..e2e79bd3fdcf
--- /dev/null
+++ b/drivers/dax/pmem/Makefile
@@ -0,0 +1,7 @@
+obj-$(CONFIG_DEV_DAX_PMEM) += dax_pmem.o
+obj-$(CONFIG_DEV_DAX_PMEM) += dax_pmem_core.o
+obj-$(CONFIG_DEV_DAX_PMEM_COMPAT) += dax_pmem_compat.o
+
+dax_pmem-y := pmem.o
+dax_pmem_core-y := core.o
+dax_pmem_compat-y := compat.o
diff --git a/drivers/dax/pmem/compat.c b/drivers/dax/pmem/compat.c
new file mode 100644
index 000000000000..d7b15e6f30c5
--- /dev/null
+++ b/drivers/dax/pmem/compat.c
@@ -0,0 +1,73 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright(c) 2016 - 2018 Intel Corporation. All rights reserved. */
+#include <linux/percpu-refcount.h>
+#include <linux/memremap.h>
+#include <linux/module.h>
+#include <linux/pfn_t.h>
+#include <linux/nd.h>
+#include "../bus.h"
+
+/* we need the private definitions to implement compat suport */
+#include "../dax-private.h"
+
+static int dax_pmem_compat_probe(struct device *dev)
+{
+ struct dev_dax *dev_dax = __dax_pmem_probe(dev, DEV_DAX_CLASS);
+ int rc;
+
+ if (IS_ERR(dev_dax))
+ return PTR_ERR(dev_dax);
+
+ if (!devres_open_group(&dev_dax->dev, dev_dax, GFP_KERNEL))
+ return -ENOMEM;
+
+ device_lock(&dev_dax->dev);
+ rc = dev_dax_probe(&dev_dax->dev);
+ device_unlock(&dev_dax->dev);
+
+ devres_close_group(&dev_dax->dev, dev_dax);
+ if (rc)
+ devres_release_group(&dev_dax->dev, dev_dax);
+
+ return rc;
+}
+
+static int dax_pmem_compat_release(struct device *dev, void *data)
+{
+ device_lock(dev);
+ devres_release_group(dev, to_dev_dax(dev));
+ device_unlock(dev);
+
+ return 0;
+}
+
+static int dax_pmem_compat_remove(struct device *dev)
+{
+ device_for_each_child(dev, NULL, dax_pmem_compat_release);
+ return 0;
+}
+
+static struct nd_device_driver dax_pmem_compat_driver = {
+ .probe = dax_pmem_compat_probe,
+ .remove = dax_pmem_compat_remove,
+ .drv = {
+ .name = "dax_pmem_compat",
+ },
+ .type = ND_DRIVER_DAX_PMEM,
+};
+
+static int __init dax_pmem_compat_init(void)
+{
+ return nd_driver_register(&dax_pmem_compat_driver);
+}
+module_init(dax_pmem_compat_init);
+
+static void __exit dax_pmem_compat_exit(void)
+{
+ driver_unregister(&dax_pmem_compat_driver.drv);
+}
+module_exit(dax_pmem_compat_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Intel Corporation");
+MODULE_ALIAS_ND_DEVICE(ND_DEVICE_DAX_PMEM);
diff --git a/drivers/dax/pmem/core.c b/drivers/dax/pmem/core.c
new file mode 100644
index 000000000000..bdcff1b14e95
--- /dev/null
+++ b/drivers/dax/pmem/core.c
@@ -0,0 +1,69 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright(c) 2016 - 2018 Intel Corporation. All rights reserved. */
+#include <linux/memremap.h>
+#include <linux/module.h>
+#include <linux/pfn_t.h>
+#include "../../nvdimm/pfn.h"
+#include "../../nvdimm/nd.h"
+#include "../bus.h"
+
+struct dev_dax *__dax_pmem_probe(struct device *dev, enum dev_dax_subsys subsys)
+{
+ struct resource res;
+ int rc, id, region_id;
+ resource_size_t offset;
+ struct nd_pfn_sb *pfn_sb;
+ struct dev_dax *dev_dax;
+ struct nd_namespace_io *nsio;
+ struct dax_region *dax_region;
+ struct dev_pagemap pgmap = { 0 };
+ struct nd_namespace_common *ndns;
+ struct nd_dax *nd_dax = to_nd_dax(dev);
+ struct nd_pfn *nd_pfn = &nd_dax->nd_pfn;
+
+ ndns = nvdimm_namespace_common_probe(dev);
+ if (IS_ERR(ndns))
+ return ERR_CAST(ndns);
+ nsio = to_nd_namespace_io(&ndns->dev);
+
+ /* parse the 'pfn' info block via ->rw_bytes */
+ rc = devm_nsio_enable(dev, nsio);
+ if (rc)
+ return ERR_PTR(rc);
+ rc = nvdimm_setup_pfn(nd_pfn, &pgmap);
+ if (rc)
+ return ERR_PTR(rc);
+ devm_nsio_disable(dev, nsio);
+
+ /* reserve the metadata area, device-dax will reserve the data */
+ pfn_sb = nd_pfn->pfn_sb;
+ offset = le64_to_cpu(pfn_sb->dataoff);
+ if (!devm_request_mem_region(dev, nsio->res.start, offset,
+ dev_name(&ndns->dev))) {
+ dev_warn(dev, "could not reserve metadata\n");
+ return ERR_PTR(-EBUSY);
+ }
+
+ rc = sscanf(dev_name(&ndns->dev), "namespace%d.%d", &region_id, &id);
+ if (rc != 2)
+ return ERR_PTR(-EINVAL);
+
+ /* adjust the dax_region resource to the start of data */
+ memcpy(&res, &pgmap.res, sizeof(res));
+ res.start += offset;
+ dax_region = alloc_dax_region(dev, region_id, &res,
+ le32_to_cpu(pfn_sb->align), PFN_DEV|PFN_MAP);
+ if (!dax_region)
+ return ERR_PTR(-ENOMEM);
+
+ dev_dax = __devm_create_dev_dax(dax_region, id, &pgmap, subsys);
+
+ /* child dev_dax instances now own the lifetime of the dax_region */
+ dax_region_put(dax_region);
+
+ return dev_dax;
+}
+EXPORT_SYMBOL_GPL(__dax_pmem_probe);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Intel Corporation");
diff --git a/drivers/dax/pmem/pmem.c b/drivers/dax/pmem/pmem.c
new file mode 100644
index 000000000000..0ae4238a0ef8
--- /dev/null
+++ b/drivers/dax/pmem/pmem.c
@@ -0,0 +1,40 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright(c) 2016 - 2018 Intel Corporation. All rights reserved. */
+#include <linux/percpu-refcount.h>
+#include <linux/memremap.h>
+#include <linux/module.h>
+#include <linux/pfn_t.h>
+#include <linux/nd.h>
+#include "../bus.h"
+
+static int dax_pmem_probe(struct device *dev)
+{
+ return PTR_ERR_OR_ZERO(__dax_pmem_probe(dev, DEV_DAX_BUS));
+}
+
+static struct nd_device_driver dax_pmem_driver = {
+ .probe = dax_pmem_probe,
+ .drv = {
+ .name = "dax_pmem",
+ },
+ .type = ND_DRIVER_DAX_PMEM,
+};
+
+static int __init dax_pmem_init(void)
+{
+ return nd_driver_register(&dax_pmem_driver);
+}
+module_init(dax_pmem_init);
+
+static void __exit dax_pmem_exit(void)
+{
+ driver_unregister(&dax_pmem_driver.drv);
+}
+module_exit(dax_pmem_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Intel Corporation");
+#if !IS_ENABLED(CONFIG_DEV_DAX_PMEM_COMPAT)
+/* For compat builds, don't load this module by default */
+MODULE_ALIAS_ND_DEVICE(ND_DEVICE_DAX_PMEM);
+#endif