[PATCH 12/21] nd_pmem: add NFIT support to the pmem driver
From: Dan Williams
Date: Fri Apr 17 2015 - 21:39:10 EST
nd_pmem attaches to persistent memory regions and namespaces emitted by
the nd subsystem, and, same as the original pmem driver, presents the
system-physical-address range as a block device.
Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
Cc: Boaz Harrosh <boaz@xxxxxxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Jens Axboe <axboe@xxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
drivers/block/Kconfig | 11 -------
drivers/block/Makefile | 1 -
drivers/block/nd/Kconfig | 17 +++++++++++
drivers/block/nd/Makefile | 3 ++
drivers/block/nd/pmem.c | 72 +++++++++++++++++++++++++++++++++++++++------
5 files changed, 83 insertions(+), 21 deletions(-)
rename drivers/block/{pmem.c => nd/pmem.c} (81%)
diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig
index dfe40e5ca9bd..1cef4ffb16c5 100644
--- a/drivers/block/Kconfig
+++ b/drivers/block/Kconfig
@@ -406,17 +406,6 @@ config BLK_DEV_RAM_DAX
and will prevent RAM block device backing store memory from being
allocated from highmem (only a problem for highmem systems).
-config BLK_DEV_PMEM
- tristate "Persistent memory block device support"
- help
- Saying Y here will allow you to use a contiguous range of reserved
- memory as one or more persistent block devices.
-
- To compile this driver as a module, choose M here: the module will be
- called 'pmem'.
-
- If unsure, say N.
-
config CDROM_PKTCDVD
tristate "Packet writing on CD/DVD media"
depends on !UML
diff --git a/drivers/block/Makefile b/drivers/block/Makefile
index 18b27bb9cd2d..3a2f15be66a3 100644
--- a/drivers/block/Makefile
+++ b/drivers/block/Makefile
@@ -14,7 +14,6 @@ obj-$(CONFIG_PS3_VRAM) += ps3vram.o
obj-$(CONFIG_ATARI_FLOPPY) += ataflop.o
obj-$(CONFIG_AMIGA_Z2RAM) += z2ram.o
obj-$(CONFIG_BLK_DEV_RAM) += brd.o
-obj-$(CONFIG_BLK_DEV_PMEM) += pmem.o
obj-$(CONFIG_BLK_DEV_LOOP) += loop.o
obj-$(CONFIG_BLK_CPQ_DA) += cpqarray.o
obj-$(CONFIG_BLK_CPQ_CISS_DA) += cciss.o
diff --git a/drivers/block/nd/Kconfig b/drivers/block/nd/Kconfig
index 6c15d10bf4e0..38eae5f0ae4b 100644
--- a/drivers/block/nd/Kconfig
+++ b/drivers/block/nd/Kconfig
@@ -72,4 +72,21 @@ config NFIT_TEST
Say N unless you are doing development of the 'nd' subsystem.
+config BLK_DEV_PMEM
+ tristate "PMEM: Persistent memory block device support"
+ depends on ND_CORE || X86_PMEM_LEGACY
+ default ND_CORE
+ help
+ Memory ranges for PMEM are described by either an NFIT
+ (NVDIMM Firmware Interface Table, see CONFIG_NFIT_ACPI), a
+ non-standard OEM-specific E820 memory type (type-12, see
+ CONFIG_X86_PMEM_LEGACY), or it is manually specified by the
+ 'memmap=nn[KMG]!ss[KMG]' kernel command line (see
+ Documentation/kernel-parameters.txt). This driver converts
+ these persistent memory ranges into block devices that are
+ capable of DAX (direct-access) file system mappings. See
+ Documentation/blockdev/nd.txt for more details.
+
+ Say Y if you want to use a NVDIMM described by NFIT
+
endif
diff --git a/drivers/block/nd/Makefile b/drivers/block/nd/Makefile
index 769ddc34f974..c0194d52e5ad 100644
--- a/drivers/block/nd/Makefile
+++ b/drivers/block/nd/Makefile
@@ -16,6 +16,7 @@ endif
obj-$(CONFIG_ND_CORE) += nd.o
obj-$(CONFIG_NFIT_ACPI) += nd_acpi.o
+obj-$(CONFIG_BLK_DEV_PMEM) += nd_pmem.o
nd_acpi-y := acpi.o
@@ -26,3 +27,5 @@ nd-y += dimm.o
nd-y += region_devs.o
nd-y += region.o
nd-y += namespace_devs.o
+
+nd_pmem-y := pmem.o
diff --git a/drivers/block/pmem.c b/drivers/block/nd/pmem.c
similarity index 81%
rename from drivers/block/pmem.c
rename to drivers/block/nd/pmem.c
index eabf4a8d0085..cd83a9a98d89 100644
--- a/drivers/block/pmem.c
+++ b/drivers/block/nd/pmem.c
@@ -1,7 +1,7 @@
/*
* Persistent Memory Driver
*
- * Copyright (c) 2014, Intel Corporation.
+ * Copyright (c) 2014-2015, Intel Corporation.
* Copyright (c) 2015, Christoph Hellwig <hch@xxxxxx>.
* Copyright (c) 2015, Boaz Harrosh <boaz@xxxxxxxxxxxxx>.
*
@@ -23,6 +23,7 @@
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/slab.h>
+#include <linux/nd.h>
#define PMEM_MINORS 16
@@ -34,10 +35,11 @@ struct pmem_device {
phys_addr_t phys_addr;
void *virt_addr;
size_t size;
+ int id;
};
static int pmem_major;
-static atomic_t pmem_index;
+static DEFINE_IDA(pmem_ida);
static void pmem_do_bvec(struct pmem_device *pmem, struct page *page,
unsigned int len, unsigned int off, int rw,
@@ -122,20 +124,26 @@ static struct pmem_device *pmem_alloc(struct device *dev, struct resource *res)
{
struct pmem_device *pmem;
struct gendisk *disk;
- int idx, err;
+ int err;
err = -ENOMEM;
pmem = kzalloc(sizeof(*pmem), GFP_KERNEL);
if (!pmem)
goto out;
+ pmem->id = ida_simple_get(&pmem_ida, 0, 0, GFP_KERNEL);
+ if (pmem->id < 0) {
+ err = pmem->id;
+ goto out_free_dev;
+ }
+
pmem->phys_addr = res->start;
pmem->size = resource_size(res);
err = -EINVAL;
if (!request_mem_region(pmem->phys_addr, pmem->size, "pmem")) {
dev_warn(dev, "could not reserve region [0x%pa:0x%zx]\n", &pmem->phys_addr, pmem->size);
- goto out_free_dev;
+ goto out_free_ida;
}
/*
@@ -159,15 +167,13 @@ static struct pmem_device *pmem_alloc(struct device *dev, struct resource *res)
if (!disk)
goto out_free_queue;
- idx = atomic_inc_return(&pmem_index) - 1;
-
disk->major = pmem_major;
- disk->first_minor = PMEM_MINORS * idx;
+ disk->first_minor = PMEM_MINORS * pmem->id;
disk->fops = &pmem_fops;
disk->private_data = pmem;
disk->queue = pmem->pmem_queue;
disk->flags = GENHD_FL_EXT_DEVT;
- sprintf(disk->disk_name, "pmem%d", idx);
+ sprintf(disk->disk_name, "pmem%d", pmem->id);
disk->driverfs_dev = dev;
set_capacity(disk, pmem->size >> 9);
pmem->pmem_disk = disk;
@@ -182,6 +188,8 @@ out_unmap:
iounmap(pmem->virt_addr);
out_release_region:
release_mem_region(pmem->phys_addr, pmem->size);
+out_free_ida:
+ ida_simple_remove(&pmem_ida, pmem->id);
out_free_dev:
kfree(pmem);
out:
@@ -195,6 +203,7 @@ static void pmem_free(struct pmem_device *pmem)
blk_cleanup_queue(pmem->pmem_queue);
iounmap(pmem->virt_addr);
release_mem_region(pmem->phys_addr, pmem->size);
+ ida_simple_remove(&pmem_ida, pmem->id);
kfree(pmem);
}
@@ -236,6 +245,39 @@ static struct platform_driver pmem_driver = {
},
};
+static int nd_pmem_probe(struct device *dev)
+{
+ struct nd_namespace_io *nsio = to_nd_namespace_io(dev);
+ struct pmem_device *pmem;
+
+ pmem = pmem_alloc(dev, &nsio->res);
+ if (IS_ERR(pmem))
+ return PTR_ERR(pmem);
+
+ dev_set_drvdata(dev, pmem);
+
+ return 0;
+}
+
+static int nd_pmem_remove(struct device *dev)
+{
+ struct pmem_device *pmem = dev_get_drvdata(dev);
+
+ pmem_free(pmem);
+ return 0;
+}
+
+MODULE_ALIAS("pmem");
+MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_IO);
+static struct nd_device_driver nd_pmem_driver = {
+ .probe = nd_pmem_probe,
+ .remove = nd_pmem_remove,
+ .drv = {
+ .name = "pmem",
+ },
+ .type = ND_DRIVER_NAMESPACE_IO,
+};
+
static int __init pmem_init(void)
{
int error;
@@ -244,9 +286,20 @@ static int __init pmem_init(void)
if (pmem_major < 0)
return pmem_major;
+ error = nd_driver_register(&nd_pmem_driver);
+ if (error)
+ goto out_unregister_blkdev;
+
error = platform_driver_register(&pmem_driver);
if (error)
- unregister_blkdev(pmem_major, "pmem");
+ goto out_unregister_nd;
+
+ return 0;
+
+ out_unregister_nd:
+ driver_unregister(&nd_pmem_driver.drv);
+ out_unregister_blkdev:
+ unregister_blkdev(pmem_major, "pmem");
return error;
}
module_init(pmem_init);
@@ -254,6 +307,7 @@ module_init(pmem_init);
static void pmem_exit(void)
{
platform_driver_unregister(&pmem_driver);
+ driver_unregister(&nd_pmem_driver.drv);
unregister_blkdev(pmem_major, "pmem");
}
module_exit(pmem_exit);
--
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