[PATCH v5 09/21] libnvdimm, nd_pmem: add libnvdimm support to the pmem driver

Dan Williams
2015-06-02T00:22:25Z

nd_pmem attaches to persistent memory regions and namespaces emitted by
the libnvdimm subsystem, and, same as the original pmem driver, presents
the system-physical-address range as a block device.

The existing e820-type-12 to pmem setup is converted to a full libnvdimm
bus that emits an nd_namespace_io device.

Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Boaz Harrosh <boaz@plexistor.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jens Axboe <axboe@fb.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
arch/x86/Kconfig | 4 ++
arch/x86/kernel/pmem.c | 92 +++++++++++++++++++++++++++++++----------------
drivers/block/Kconfig | 11 ------
drivers/block/Makefile | 1 -
drivers/nvdimm/Kconfig | 17 +++++++++
drivers/nvdimm/Makefile | 3 ++
drivers/nvdimm/pmem.c | 60 +++++++++++++++----------------
7 files changed, 113 insertions(+), 75 deletions(-)
rename drivers/{block/pmem.c => nvdimm/pmem.c} (85%)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 226d5696e1d1..3fa273d47bba 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1424,6 +1424,10 @@ source "mm/Kconfig"

config X86_PMEM_LEGACY
bool "Support non-standard NVDIMMs and ADR protected memory"
+ depends on PHYS_ADDR_T_64BIT
+ depends on BLK_DEV
+ select NVDIMM_DEVICES
+ select LIBNVDIMM
help
Treat memory marked using the non-standard e820 type of 12 as used
by the Intel Sandy Bridge-EP reference BIOS as protected memory.
diff --git a/arch/x86/kernel/pmem.c b/arch/x86/kernel/pmem.c
index 3420c874ddc5..40d734c8e3b1 100644
--- a/arch/x86/kernel/pmem.c
+++ b/arch/x86/kernel/pmem.c
@@ -1,53 +1,81 @@
/*
* Copyright (c) 2015, Christoph Hellwig.
+ * Copyright (c) 2015, Intel Corporation.
*/
-#include <linux/memblock.h>
#include <linux/platform_device.h>
-#include <linux/slab.h>
+#include <linux/libnvdimm.h>
+#include <linux/module.h>
#include <asm/e820.h>
-#include <asm/page_types.h>
-#include <asm/setup.h>

-static __init void register_pmem_device(struct resource *res)
+static void e820_pmem_release(struct device *dev)
{
- struct platform_device *pdev;
- int error;
+ struct nvdimm_bus *nvdimm_bus = dev->platform_data;

- pdev = platform_device_alloc("pmem", PLATFORM_DEVID_AUTO);
- if (!pdev)
- return;
+ if (nvdimm_bus)
+ nvdimm_bus_unregister(nvdimm_bus);
+}

- error = platform_device_add_resources(pdev, res, 1);
- if (error)
- goto out_put_pdev;
+static struct platform_device e820_pmem = {
+ .name = "e820_pmem",
+ .id = -1,
+ .dev = {
+ .release = e820_pmem_release,
+ },
+};

- error = platform_device_add(pdev);
- if (error)
- goto out_put_pdev;
- return;
+static const struct attribute_group *e820_pmem_attribute_groups[] = {
+ &nvdimm_bus_attribute_group,
+ NULL,
+};

-out_put_pdev:
- dev_warn(&pdev->dev, "failed to add 'pmem' (persistent memory) device!\n");
- platform_device_put(pdev);
-}
+static const struct attribute_group *e820_pmem_region_attribute_groups[] = {
+ &nd_region_attribute_group,
+ &nd_device_attribute_group,
+ NULL,
+};

-static __init int register_pmem_devices(void)
+static __init int register_e820_pmem(void)
{
- int i;
+ static struct nvdimm_bus_descriptor nd_desc;
+ struct device *dev = &e820_pmem.dev;
+ struct nvdimm_bus *nvdimm_bus;
+ int rc, i;
+
+ rc = platform_device_register(&e820_pmem);
+ if (rc)
+ return rc;
+
+ nd_desc.attr_groups = e820_pmem_attribute_groups;
+ nd_desc.provider_name = "e820";
+ nvdimm_bus = nvdimm_bus_register(dev, &nd_desc);
+ if (!nvdimm_bus)
+ goto err;
+ dev->platform_data = nvdimm_bus;

for (i = 0; i < e820.nr_map; i++) {
struct e820entry *ei = &e820.map[i];
+ struct resource res = {
+ .flags = IORESOURCE_MEM,
+ .start = ei->addr,
+ .end = ei->addr + ei->size - 1,
+ };
+ struct nd_region_desc ndr_desc;
+
+ if (ei->type != E820_PRAM)
+ continue;

- if (ei->type == E820_PRAM) {
- struct resource res = {
- .flags = IORESOURCE_MEM,
- .start = ei->addr,
- .end = ei->addr + ei->size - 1,
- };
- register_pmem_device(&res);
- }
+ memset(&ndr_desc, 0, sizeof(ndr_desc));
+ ndr_desc.res = &res;
+ ndr_desc.attr_groups = e820_pmem_region_attribute_groups;
+ if (!nvdimm_pmem_region_create(nvdimm_bus, &ndr_desc))
+ goto err;
}

return 0;
+
+ err:
+ dev_err(dev, "failed to register legacy persistent memory ranges\n");
+ platform_device_unregister(&e820_pmem);
+ return -ENXIO;
}
-device_initcall(register_pmem_devices);
+late_initcall(register_e820_pmem);
diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig
index eb1fed5bd516..1b8094d4d7af 100644
--- a/drivers/block/Kconfig
+++ b/drivers/block/Kconfig
@@ -404,17 +404,6 @@ 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 9cc6c18a1c7e..02b688d1438d 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/nvdimm/Kconfig b/drivers/nvdimm/Kconfig
index 24b51dbc8215..020acf860258 100644
--- a/drivers/nvdimm/Kconfig
+++ b/drivers/nvdimm/Kconfig
@@ -17,4 +17,21 @@ if NVDIMM_DEVICES
config LIBNVDIMM
tristate

+config BLK_DEV_PMEM
+ tristate "PMEM: Persistent memory block device support"
+ depends on LIBNVDIMM
+ default LIBNVDIMM
+ 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/nvdimm/Makefile b/drivers/nvdimm/Makefile
index af5e2760ddbd..4d2a27f52faa 100644
--- a/drivers/nvdimm/Makefile
+++ b/drivers/nvdimm/Makefile
@@ -1,4 +1,7 @@
obj-$(CONFIG_LIBNVDIMM) += libnvdimm.o
+obj-$(CONFIG_BLK_DEV_PMEM) += nd_pmem.o
+
+nd_pmem-y := pmem.o

libnvdimm-y := core.o
libnvdimm-y += bus.o
diff --git a/drivers/block/pmem.c b/drivers/nvdimm/pmem.c
similarity index 85%
rename from drivers/block/pmem.c
rename to drivers/nvdimm/pmem.c
index eabf4a8d0085..cf5d53eda9e5 100644
--- a/drivers/block/pmem.c
+++ b/drivers/nvdimm/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@lst.de>.
* Copyright (c) 2015, Boaz Harrosh <boaz@plexistor.com>.
*
@@ -23,6 +23,8 @@
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/slab.h>
+#include <linux/nd.h>
+#include "nd.h"

#define PMEM_MINORS 16

@@ -37,7 +39,6 @@ struct pmem_device {
};

static int pmem_major;
-static atomic_t pmem_index;

static void pmem_do_bvec(struct pmem_device *pmem, struct page *page,
unsigned int len, unsigned int off, int rw,
@@ -118,11 +119,11 @@ static const struct block_device_operations pmem_fops = {
.direct_access = pmem_direct_access,
};

-static struct pmem_device *pmem_alloc(struct device *dev, struct resource *res)
+static struct pmem_device *pmem_alloc(struct device *dev, struct resource *res, int id)
{
struct pmem_device *pmem;
struct gendisk *disk;
- int idx, err;
+ int err;

err = -ENOMEM;
pmem = kzalloc(sizeof(*pmem), GFP_KERNEL);
@@ -159,15 +160,13 @@ 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 * 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", id);
disk->driverfs_dev = dev;
set_capacity(disk, pmem->size >> 9);
pmem->pmem_disk = disk;
@@ -198,42 +197,38 @@ static void pmem_free(struct pmem_device *pmem)
kfree(pmem);
}

-static int pmem_probe(struct platform_device *pdev)
+static int nd_pmem_probe(struct device *dev)
{
+ struct nd_region *nd_region = to_nd_region(dev->parent);
+ struct nd_namespace_io *nsio = to_nd_namespace_io(dev);
struct pmem_device *pmem;
- struct resource *res;
-
- if (WARN_ON(pdev->num_resources > 1))
- return -ENXIO;
-
- res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- if (!res)
- return -ENXIO;

- pmem = pmem_alloc(&pdev->dev, res);
+ pmem = pmem_alloc(dev, &nsio->res, nd_region->id);
if (IS_ERR(pmem))
return PTR_ERR(pmem);

- platform_set_drvdata(pdev, pmem);
+ dev_set_drvdata(dev, pmem);

return 0;
}

-static int pmem_remove(struct platform_device *pdev)
+static int nd_pmem_remove(struct device *dev)
{
- struct pmem_device *pmem = platform_get_drvdata(pdev);
+ struct pmem_device *pmem = dev_get_drvdata(dev);

pmem_free(pmem);
return 0;
}

-static struct platform_driver pmem_driver = {
- .probe = pmem_probe,
- .remove = pmem_remove,
- .driver = {
- .owner = THIS_MODULE,
- .name = "pmem",
+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 = "nd_pmem",
},
+ .type = ND_DRIVER_NAMESPACE_IO,
};

static int __init pmem_init(void)
@@ -244,16 +239,19 @@ static int __init pmem_init(void)
if (pmem_major < 0)
return pmem_major;

- error = platform_driver_register(&pmem_driver);
- if (error)
+ error = nd_driver_register(&nd_pmem_driver);
+ if (error) {
unregister_blkdev(pmem_major, "pmem");
- return error;
+ return error;
+ }
+
+ return 0;
}
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);