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Commit 7a2765f6 authored by Dan Williams's avatar Dan Williams
Browse files

dcssblk: add dax_operations support 



Setup a dax_dev to have the same lifetime as the dcssblk block device
and add a ->direct_access() method that is equivalent to
dcssblk_direct_access(). Once fs/dax.c has been converted to use
dax_operations the old dcssblk_direct_access() will be removed.

Reported-by: default avatarGerald Schaefer <gerald.schaefer@de.ibm.com>
Acked-by: default avatarGerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent 1647b9b9

drivers/s390/block/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ config BLK_DEV_XPRAM 


config DCSSBLK

	def_tristate m

	select DAX

	prompt "DCSSBLK support"

	depends on S390 && BLOCK

	help

drivers/s390/block/dcssblk.c

+46 −9
Original line number Diff line number Diff line
@@ -18,6 +18,7 @@ 
#include <linux/interrupt.h>

#include <linux/platform_device.h>

#include <linux/pfn_t.h>

#include <linux/dax.h>

#include <asm/extmem.h>

#include <asm/io.h>
@@ -30,8 +31,10 @@ static int dcssblk_open(struct block_device *bdev, fmode_t mode); 
static void dcssblk_release(struct gendisk *disk, fmode_t mode);

static blk_qc_t dcssblk_make_request(struct request_queue *q,

						struct bio *bio);

static long dcssblk_direct_access(struct block_device *bdev, sector_t secnum,

static long dcssblk_blk_direct_access(struct block_device *bdev, sector_t secnum,

			 void **kaddr, pfn_t *pfn, long size);

static long dcssblk_dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff,

		long nr_pages, void **kaddr, pfn_t *pfn);



static char dcssblk_segments[DCSSBLK_PARM_LEN] = "\0";
@@ -40,7 +43,11 @@ static const struct block_device_operations dcssblk_devops = { 
	.owner   	= THIS_MODULE,

	.open    	= dcssblk_open,

	.release 	= dcssblk_release,

	.direct_access 	= dcssblk_direct_access,

	.direct_access 	= dcssblk_blk_direct_access,

};



static const struct dax_operations dcssblk_dax_ops = {

	.direct_access = dcssblk_dax_direct_access,

};



struct dcssblk_dev_info {
@@ -57,6 +64,7 @@ struct dcssblk_dev_info { 
	struct request_queue *dcssblk_queue;

	int num_of_segments;

	struct list_head seg_list;

	struct dax_device *dax_dev;

};



struct segment_info {
@@ -389,6 +397,8 @@ dcssblk_shared_store(struct device *dev, struct device_attribute *attr, const ch 
	}

	list_del(&dev_info->lh);



	kill_dax(dev_info->dax_dev);

	put_dax(dev_info->dax_dev);

	del_gendisk(dev_info->gd);

	blk_cleanup_queue(dev_info->dcssblk_queue);

	dev_info->gd->queue = NULL;
@@ -654,6 +664,13 @@ dcssblk_add_store(struct device *dev, struct device_attribute *attr, const char 
	if (rc)

		goto put_dev;



	dev_info->dax_dev = alloc_dax(dev_info, dev_info->gd->disk_name,

			&dcssblk_dax_ops);

	if (!dev_info->dax_dev) {

		rc = -ENOMEM;

		goto put_dev;

	}



	get_device(&dev_info->dev);

	device_add_disk(&dev_info->dev, dev_info->gd);
@@ -752,6 +769,8 @@ dcssblk_remove_store(struct device *dev, struct device_attribute *attr, const ch 
	}



	list_del(&dev_info->lh);

	kill_dax(dev_info->dax_dev);

	put_dax(dev_info->dax_dev);

	del_gendisk(dev_info->gd);

	blk_cleanup_queue(dev_info->dcssblk_queue);

	dev_info->gd->queue = NULL;
@@ -883,21 +902,39 @@ dcssblk_make_request(struct request_queue *q, struct bio *bio) 
}



static long

dcssblk_direct_access (struct block_device *bdev, sector_t secnum,

__dcssblk_direct_access(struct dcssblk_dev_info *dev_info, pgoff_t pgoff,

		long nr_pages, void **kaddr, pfn_t *pfn)

{

	resource_size_t offset = pgoff * PAGE_SIZE;

	unsigned long dev_sz;



	dev_sz = dev_info->end - dev_info->start + 1;

	*kaddr = (void *) dev_info->start + offset;

	*pfn = __pfn_to_pfn_t(PFN_DOWN(dev_info->start + offset), PFN_DEV);



	return (dev_sz - offset) / PAGE_SIZE;

}



static long

dcssblk_blk_direct_access(struct block_device *bdev, sector_t secnum,

			void **kaddr, pfn_t *pfn, long size)

{

	struct dcssblk_dev_info *dev_info;

	unsigned long offset, dev_sz;



	dev_info = bdev->bd_disk->private_data;

	if (!dev_info)

		return -ENODEV;

	dev_sz = dev_info->end - dev_info->start + 1;

	offset = secnum * 512;

	*kaddr = (void *) dev_info->start + offset;

	*pfn = __pfn_to_pfn_t(PFN_DOWN(dev_info->start + offset), PFN_DEV);

	return __dcssblk_direct_access(dev_info, PHYS_PFN(secnum * 512),

			PHYS_PFN(size), kaddr, pfn) * PAGE_SIZE;

}



static long

dcssblk_dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff,

		long nr_pages, void **kaddr, pfn_t *pfn)

{

	struct dcssblk_dev_info *dev_info = dax_get_private(dax_dev);



	return dev_sz - offset;

	return __dcssblk_direct_access(dev_info, pgoff, nr_pages, kaddr, pfn);

}



static void