Commit 9f53f9fa authored by Dan Williams's avatar Dan Williams
Browse files

libnvdimm, pmem: add libnvdimm support to the pmem driver 



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 an nvdimm_bus
that emits an nd_namespace_io device.

Note that the X in 'pmemX' is now derived from the parent region.  This
provides some stability to the pmem devices names from boot-to-boot.
The minor numbers are also more predictable by passing 0 to
alloc_disk().

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: default avatarRoss Zwisler <ross.zwisler@linux.intel.com>
Acked-by: default avatarChristoph Hellwig <hch@lst.de>
Tested-by: default avatarToshi Kani <toshi.kani@hp.com>
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent 18da2c9e

arch/x86/Kconfig

+3 −0
Original line number Diff line number Diff line
@@ -1424,6 +1424,9 @@ 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 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.

arch/x86/kernel/pmem.c

+60 −32
Original line number Diff line number Diff line 
/*

 * 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];



		if (ei->type == E820_PRAM) {

		struct resource res = {

			.flags	= IORESOURCE_MEM,

			.start	= ei->addr,

			.end	= ei->addr + ei->size - 1,

		};

			register_pmem_device(&res);

		}

		struct nd_region_desc ndr_desc;



		if (ei->type != E820_PRAM)

			continue;



		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);
 
device_initcall(register_e820_pmem);

drivers/nvdimm/pmem.c

+33 −35
Original line number Diff line number Diff line 
/*

 * 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>.

 *
@@ -23,8 +23,8 @@ 
#include <linux/module.h>

#include <linux/moduleparam.h>

#include <linux/slab.h>



#define PMEM_MINORS		16

#include <linux/nd.h>

#include "nd.h"



struct pmem_device {

	struct request_queue	*pmem_queue;
@@ -37,7 +37,6 @@ 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 +117,12 @@ 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);
@@ -134,7 +134,8 @@ static struct pmem_device *pmem_alloc(struct device *dev, struct resource *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);

		dev_warn(dev, "could not reserve region [0x%pa:0x%zx]\n",

				&pmem->phys_addr, pmem->size);

		goto out_free_dev;

	}
@@ -155,19 +156,17 @@ static struct pmem_device *pmem_alloc(struct device *dev, struct resource *res) 
	blk_queue_max_hw_sectors(pmem->pmem_queue, 1024);

	blk_queue_bounce_limit(pmem->pmem_queue, BLK_BOUNCE_ANY);



	disk = alloc_disk(PMEM_MINORS);

	disk = alloc_disk(0);

	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	= 0;

	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 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);

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