diff mbox series

[v3,07/10] lib/memregion: Uplevel the pmem "region" ida to a global allocator

Message ID 155993567002.3036719.5748845658364934737.stgit@dwillia2-desk3.amr.corp.intel.com (mailing list archive)
State Superseded
Headers show
Series EFI Specific Purpose Memory Support | expand

Commit Message

Dan Williams June 7, 2019, 7:27 p.m. UTC 
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.

Cc: Keith Busch <keith.busch@intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 drivers/nvdimm/Kconfig       |    1 +
 drivers/nvdimm/core.c        |    1 -
 drivers/nvdimm/nd-core.h     |    1 -
 drivers/nvdimm/region_devs.c |   13 ++++---------
 include/linux/memregion.h    |    8 ++++++++
 lib/Kconfig                  |    7 +++++++
 lib/Makefile                 |    1 +
 lib/memregion.c              |   15 +++++++++++++++
 8 files changed, 36 insertions(+), 11 deletions(-)
 create mode 100644 include/linux/memregion.h
 create mode 100644 lib/memregion.c

Comments

Matthew Wilcox June 7, 2019, 8:23 p.m. UTC | #1 
On Fri, Jun 07, 2019 at 12:27:50PM -0700, Dan Williams wrote:
> diff --git a/lib/memregion.c b/lib/memregion.c
> new file mode 100644
> index 000000000000..f6c6a94c7921
> --- /dev/null
> +++ b/lib/memregion.c
> @@ -0,0 +1,15 @@
> +#include <linux/idr.h>
> +
> +static DEFINE_IDA(region_ids);
> +
> +int memregion_alloc(gfp_t gfp)
> +{
> +	return ida_alloc(&region_ids, gfp);
> +}
> +EXPORT_SYMBOL(memregion_alloc);
> +
> +void memregion_free(int id)
> +{
> +	ida_free(&region_ids, id);
> +}
> +EXPORT_SYMBOL(memregion_free);

Does this trivial abstraction have to live in its own file?  I'd make
memregion_alloc/free static inlines that live in a header file, then
all you need do is find a suitable .c file to store memregion_ids in,
and export that one symbol instead of two.
Dan Williams June 21, 2019, 8:35 p.m. UTC | #2 
On Fri, Jun 7, 2019 at 1:23 PM Matthew Wilcox <willy@infradead.org> wrote:
>
> On Fri, Jun 07, 2019 at 12:27:50PM -0700, Dan Williams wrote:
> > diff --git a/lib/memregion.c b/lib/memregion.c
> > new file mode 100644
> > index 000000000000..f6c6a94c7921
> > --- /dev/null
> > +++ b/lib/memregion.c
> > @@ -0,0 +1,15 @@
> > +#include <linux/idr.h>
> > +
> > +static DEFINE_IDA(region_ids);
> > +
> > +int memregion_alloc(gfp_t gfp)
> > +{
> > +     return ida_alloc(&region_ids, gfp);
> > +}
> > +EXPORT_SYMBOL(memregion_alloc);
> > +
> > +void memregion_free(int id)
> > +{
> > +     ida_free(&region_ids, id);
> > +}
> > +EXPORT_SYMBOL(memregion_free);
>
> Does this trivial abstraction have to live in its own file?  I'd make
> memregion_alloc/free static inlines that live in a header file, then
> all you need do is find a suitable .c file to store memregion_ids in,
> and export that one symbol instead of two.

Ok, I think since these "memregion" objects tend to be closely related
to "device memory" I'll stash this in kernel/memremap.c with the rest
of the "ZONE_DEVICE" apis.
Dan Williams Aug. 27, 2019, 5:48 a.m. UTC | #3 
On Fri, Jun 7, 2019 at 1:23 PM Matthew Wilcox <willy@infradead.org> wrote:
>
> On Fri, Jun 07, 2019 at 12:27:50PM -0700, Dan Williams wrote:
> > diff --git a/lib/memregion.c b/lib/memregion.c
> > new file mode 100644
> > index 000000000000..f6c6a94c7921
> > --- /dev/null
> > +++ b/lib/memregion.c
> > @@ -0,0 +1,15 @@
> > +#include <linux/idr.h>
> > +
> > +static DEFINE_IDA(region_ids);
> > +
> > +int memregion_alloc(gfp_t gfp)
> > +{
> > +     return ida_alloc(&region_ids, gfp);
> > +}
> > +EXPORT_SYMBOL(memregion_alloc);
> > +
> > +void memregion_free(int id)
> > +{
> > +     ida_free(&region_ids, id);
> > +}
> > +EXPORT_SYMBOL(memregion_free);
>
> Does this trivial abstraction have to live in its own file?  I'd make
> memregion_alloc/free static inlines that live in a header file, then
> all you need do is find a suitable .c file to store memregion_ids in,
> and export that one symbol instead of two.

It turns out yes, this needs to live in its own file. It's an optional
library that does not fit anywhere else, everywhere I've thought to
stash it has either triggered obscure build errors based on idr.h
include dependencies or does not fit due to build dependencies.
diff mbox series

Patch

diff --git a/drivers/nvdimm/Kconfig b/drivers/nvdimm/Kconfig
index 54500798f23a..4b3e66fe61c1 100644
--- 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 acce050856a8..75fe651d327d 100644
--- a/drivers/nvdimm/core.c
+++ b/drivers/nvdimm/core.c
@@ -463,7 +463,6 @@  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 e5ffd5733540..17561302dfec 100644
--- a/drivers/nvdimm/nd-core.h
+++ b/drivers/nvdimm/nd-core.h
@@ -133,7 +133,6 @@  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);
 void nd_region_probe_success(struct nvdimm_bus *nvdimm_bus, struct device *dev);
 struct nd_region;
 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 b4ef7d9ff22e..9e070363ff70 100644
--- a/drivers/nvdimm/region_devs.c
+++ b/drivers/nvdimm/region_devs.c
@@ -11,6 +11,7 @@ 
  * General Public License for more details.
  */
 #include <linux/scatterlist.h>
+#include <linux/memregion.h>
 #include <linux/highmem.h>
 #include <linux/sched.h>
 #include <linux/slab.h>
@@ -27,7 +28,6 @@ 
  */
 #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,
@@ -141,7 +141,7 @@  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
@@ -1036,7 +1036,7 @@  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;
 
@@ -1090,7 +1090,7 @@  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;
@@ -1237,8 +1237,3 @@  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
index 000000000000..ba03c70f98d2
--- /dev/null
+++ b/include/linux/memregion.h
@@ -0,0 +1,8 @@ 
+// SPDX-License-Identifier: GPL-2.0
+#ifndef _MEMREGION_H_
+#define _MEMREGION_H_
+#include <linux/types.h>
+
+int memregion_alloc(gfp_t gfp);
+void memregion_free(int id);
+#endif /* _MEMREGION_H_ */
diff --git a/lib/Kconfig b/lib/Kconfig
index 90623a0e1942..68621a0505a6 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -335,6 +335,13 @@  config DECOMPRESS_LZ4
 config GENERIC_ALLOCATOR
 	bool
 
+#
+# Memory Region ID allocation for persistent memory and "specific
+# purpose" / performance differentiated memory ranges.
+#
+config MEMREGION
+	bool
+
 #
 # reed solomon support is select'ed if needed
 #
diff --git a/lib/Makefile b/lib/Makefile
index fb7697031a79..58cf99f68f36 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -136,6 +136,7 @@  obj-$(CONFIG_LIBCRC32C)	+= libcrc32c.o
 obj-$(CONFIG_CRC8)	+= crc8.o
 obj-$(CONFIG_XXHASH)	+= xxhash.o
 obj-$(CONFIG_GENERIC_ALLOCATOR) += genalloc.o
+obj-$(CONFIG_MEMREGION) += memregion.o
 
 obj-$(CONFIG_842_COMPRESS) += 842/
 obj-$(CONFIG_842_DECOMPRESS) += 842/
diff --git a/lib/memregion.c b/lib/memregion.c
new file mode 100644
index 000000000000..f6c6a94c7921
--- /dev/null
+++ b/lib/memregion.c
@@ -0,0 +1,15 @@ 
+#include <linux/idr.h>
+
+static DEFINE_IDA(region_ids);
+
+int memregion_alloc(gfp_t gfp)
+{
+	return ida_alloc(&region_ids, gfp);
+}
+EXPORT_SYMBOL(memregion_alloc);
+
+void memregion_free(int id)
+{
+	ida_free(&region_ids, id);
+}
+EXPORT_SYMBOL(memregion_free);