lib: Uplevel the pmem "region" ida to a global allocator

In preparation for handling platform differentiated memory types beyond
persistent memory, uplevel the "region" identifier to a global number
space. This enables a device-dax instance to be registered to any memory
type with guaranteed unique names.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/nvdimm/Kconfig b/drivers/nvdimm/Kconfig
index 36af7af6b7cfee351e6e8f9e39d895726bd736dd..b7d1eb38b27d464f15b610908ae1a7d8ac39b6a3 100644 (file)
--- a/drivers/nvdimm/Kconfig
+++ b/drivers/nvdimm/Kconfig
@@ -4,6 +4,7 @@ menuconfig LIBNVDIMM
        depends on PHYS_ADDR_T_64BIT
        depends on HAS_IOMEM
        depends on BLK_DEV
+       select MEMREGION
        help
          Generic support for non-volatile memory devices including
          ACPI-6-NFIT defined resources.  On platforms that define an

diff --git a/drivers/nvdimm/core.c b/drivers/nvdimm/core.c
index 9204f1e9fd1414d8650bb873969d0c3175b46f24..e592c49646748ca7a38c98eded31a902a18e1cd7 100644 (file)
--- a/drivers/nvdimm/core.c
+++ b/drivers/nvdimm/core.c
@@ -455,7 +455,6 @@ static __exit void libnvdimm_exit(void)
        nd_region_exit();
        nvdimm_exit();
        nvdimm_bus_exit();
-       nd_region_devs_exit();
        nvdimm_devs_exit();
 }
 

diff --git a/drivers/nvdimm/nd-core.h b/drivers/nvdimm/nd-core.h
index 25fa121104d04363e35dcad09e7de9a4d57e7956..aa059439fca08181fe4550dc0be097ea2b582ac3 100644 (file)
--- a/drivers/nvdimm/nd-core.h
+++ b/drivers/nvdimm/nd-core.h
@@ -114,7 +114,6 @@ struct nvdimm_bus *walk_to_nvdimm_bus(struct device *nd_dev);
 int __init nvdimm_bus_init(void);
 void nvdimm_bus_exit(void);
 void nvdimm_devs_exit(void);
-void nd_region_devs_exit(void);
 struct nd_region;
 void nd_region_advance_seeds(struct nd_region *nd_region, struct device *dev);
 void nd_region_create_ns_seed(struct nd_region *nd_region);

diff --git a/drivers/nvdimm/region_devs.c b/drivers/nvdimm/region_devs.c
index ef423ba1a71163ee742dfca9795c4f758ab4cff9..fbf34cf688f436d189de58deb5a8fb3443efb606 100644 (file)
--- a/drivers/nvdimm/region_devs.c
+++ b/drivers/nvdimm/region_devs.c
@@ -3,6 +3,7 @@
  * Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
  */
 #include <linux/scatterlist.h>
+#include <linux/memregion.h>
 #include <linux/highmem.h>
 #include <linux/sched.h>
 #include <linux/slab.h>
@@ -19,7 +20,6 @@
  */
 #include <linux/io-64-nonatomic-hi-lo.h>
 
-static DEFINE_IDA(region_ida);
 static DEFINE_PER_CPU(int, flush_idx);
 
 static int nvdimm_map_flush(struct device *dev, struct nvdimm *nvdimm, int dimm,
@@ -133,7 +133,7 @@ static void nd_region_release(struct device *dev)
                put_device(&nvdimm->dev);
        }
        free_percpu(nd_region->lane);
-       ida_simple_remove(&region_ida, nd_region->id);
+       memregion_free(nd_region->id);
        if (is_nd_blk(dev))
                kfree(to_nd_blk_region(dev));
        else
@@ -985,7 +985,7 @@ static struct nd_region *nd_region_create(struct nvdimm_bus *nvdimm_bus,
 
        if (!region_buf)
                return NULL;
-       nd_region->id = ida_simple_get(&region_ida, 0, 0, GFP_KERNEL);
+       nd_region->id = memregion_alloc(GFP_KERNEL);
        if (nd_region->id < 0)
                goto err_id;
 
@@ -1044,7 +1044,7 @@ static struct nd_region *nd_region_create(struct nvdimm_bus *nvdimm_bus,
        return nd_region;
 
  err_percpu:
-       ida_simple_remove(&region_ida, nd_region->id);
+       memregion_free(nd_region->id);
  err_id:
        kfree(region_buf);
        return NULL;
@@ -1216,8 +1216,3 @@ int nd_region_conflict(struct nd_region *nd_region, resource_size_t start,
 
        return device_for_each_child(&nvdimm_bus->dev, &ctx, region_conflict);
 }
-
-void __exit nd_region_devs_exit(void)
-{
-       ida_destroy(&region_ida);
-}

diff --git a/include/linux/memregion.h b/include/linux/memregion.h
new file mode 100644 (file)
index 0000000..7de7c0a
--- /dev/null
+++ b/include/linux/memregion.h
@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _MEMREGION_H_
+#define _MEMREGION_H_
+#include <linux/types.h>
+#include <linux/errno.h>
+
+#ifdef CONFIG_MEMREGION
+int memregion_alloc(gfp_t gfp);
+void memregion_free(int id);
+#else
+static inline int memregion_alloc(gfp_t gfp)
+{
+       return -ENOMEM;
+}
+void memregion_free(int id)
+{
+}
+#endif
+#endif /* _MEMREGION_H_ */

diff --git a/lib/Kconfig b/lib/Kconfig
index 183f92a297ca557d86de048325f78a048741e37c..0dc043ac271d23dadced45fbf55c3e34fc6ae6cc 100644 (file)
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -606,6 +606,9 @@ config ARCH_NO_SG_CHAIN
 config ARCH_HAS_PMEM_API
        bool
 
+config MEMREGION
+       bool
+
 # use memcpy to implement user copies for nommu architectures
 config UACCESS_MEMCPY
        bool

diff --git a/lib/Makefile b/lib/Makefile
index c5892807e06fa2c940103947d9272c66bcb4982d..2fb7b47018f175e2df3ec7f44c4c8f5a6ec092ed 100644 (file)
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -212,6 +212,7 @@ obj-$(CONFIG_GENERIC_NET_UTILS) += net_utils.o
 
 obj-$(CONFIG_SG_SPLIT) += sg_split.o
 obj-$(CONFIG_SG_POOL) += sg_pool.o
+obj-$(CONFIG_MEMREGION) += memregion.o
 obj-$(CONFIG_STMP_DEVICE) += stmp_device.o
 obj-$(CONFIG_IRQ_POLL) += irq_poll.o
 

diff --git a/lib/memregion.c b/lib/memregion.c
new file mode 100644 (file)
index 0000000..77c85b5
--- /dev/null
+++ b/lib/memregion.c
@@ -0,0 +1,18 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* identifiers for device / performance-differentiated memory regions */
+#include <linux/idr.h>
+#include <linux/types.h>
+
+static DEFINE_IDA(memregion_ids);
+
+int memregion_alloc(gfp_t gfp)
+{
+       return ida_alloc(&memregion_ids, gfp);
+}
+EXPORT_SYMBOL(memregion_alloc);
+
+void memregion_free(int id)
+{
+       ida_free(&memregion_ids, id);
+}
+EXPORT_SYMBOL(memregion_free);