From: Dan Williams Date: Thu, 26 Jan 2017 21:54:35 +0000 (-0800) Subject: dcssblk: add dax_operations support X-Git-Tag: v4.12-rc1~83^2^2~12 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=7a2765f6e82063f348ebce78c28eceff741689d4;p=karo-tx-linux.git 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: Gerald Schaefer Acked-by: Gerald Schaefer Signed-off-by: Dan Williams --- diff --git a/drivers/s390/block/Kconfig b/drivers/s390/block/Kconfig index 4a3b62326183..0acb8c2f9475 100644 --- a/drivers/s390/block/Kconfig +++ b/drivers/s390/block/Kconfig @@ -14,6 +14,7 @@ config BLK_DEV_XPRAM config DCSSBLK def_tristate m + select DAX prompt "DCSSBLK support" depends on S390 && BLOCK help diff --git a/drivers/s390/block/dcssblk.c b/drivers/s390/block/dcssblk.c index 415d10a67b7a..dc84cfd4e438 100644 --- a/drivers/s390/block/dcssblk.c +++ b/drivers/s390/block/dcssblk.c @@ -18,6 +18,7 @@ #include #include #include +#include #include #include @@ -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 @@ removeseg: } 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 @@ fail: } 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