pmem, dax: have direct_access use __pmem annotation

Update the annotation for the kaddr pointer returned by direct_access()
so that it is a __pmem pointer.  This is consistent with the PMEM driver
and with how this direct_access() pointer is used in the DAX code.

Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

8 files changed, 41 insertions, 34 deletions

diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking
index 6a34a0f4d37c..06d443450f21 100644
--- a/Documentation/filesystems/Locking
+++ b/Documentation/filesystems/Locking
@@ -397,7 +397,8 @@ prototypes:
         int (*release) (struct gendisk *, fmode_t);
         int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
         int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
-        int (*direct_access) (struct block_device *, sector_t, void **, unsigned long *);
+        int (*direct_access) (struct block_device *, sector_t, void __pmem **,
+                                unsigned long *);
         int (*media_changed) (struct gendisk *);
         void (*unlock_native_capacity) (struct gendisk *);
         int (*revalidate_disk) (struct gendisk *);
diff --git a/arch/powerpc/sysdev/axonram.c b/arch/powerpc/sysdev/axonram.c
index ee90db17b097..a2be2a66dab6 100644
--- a/arch/powerpc/sysdev/axonram.c
+++ b/arch/powerpc/sysdev/axonram.c
@@ -141,13 +141,14 @@ axon_ram_make_request(struct request_queue *queue, struct bio *bio)
  */
 static long
 axon_ram_direct_access(struct block_device *device, sector_t sector,
-                       void **kaddr, unsigned long *pfn, long size)
+                       void __pmem **kaddr, unsigned long *pfn, long size)
 {
         struct axon_ram_bank *bank = device->bd_disk->private_data;
         loff_t offset = (loff_t)sector << AXON_RAM_SECTOR_SHIFT;
+        void *addr = (void *)(bank->ph_addr + offset);
 
-        *kaddr = (void *)(bank->ph_addr + offset);
-        *pfn = virt_to_phys(*kaddr) >> PAGE_SHIFT;
+        *kaddr = (void __pmem *)addr;
+        *pfn = virt_to_phys(addr) >> PAGE_SHIFT;
 
         return bank->size - offset;
 }
diff --git a/drivers/block/brd.c b/drivers/block/brd.c
index 64ab4951e9d6..c96402fd1560 100644
--- a/drivers/block/brd.c
+++ b/drivers/block/brd.c
@@ -371,7 +371,7 @@ static int brd_rw_page(struct block_device *bdev, sector_t sector,
 
 #ifdef CONFIG_BLK_DEV_RAM_DAX
 static long brd_direct_access(struct block_device *bdev, sector_t sector,
-                        void **kaddr, unsigned long *pfn, long size)
+                        void __pmem **kaddr, unsigned long *pfn, long size)
 {
         struct brd_device *brd = bdev->bd_disk->private_data;
         struct page *page;
@@ -381,7 +381,7 @@ static long brd_direct_access(struct block_device *bdev, sector_t sector,
         page = brd_insert_page(brd, sector);
         if (!page)
                 return -ENOSPC;
-        *kaddr = page_address(page);
+        *kaddr = (void __pmem *)page_address(page);
         *pfn = page_to_pfn(page);
 
         /*
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index eb7552d939e1..f3b629779266 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -92,7 +92,7 @@ static int pmem_rw_page(struct block_device *bdev, sector_t sector,
 }
 
 static long pmem_direct_access(struct block_device *bdev, sector_t sector,
-                              void **kaddr, unsigned long *pfn, long size)
+                      void __pmem **kaddr, unsigned long *pfn, long size)
 {
         struct pmem_device *pmem = bdev->bd_disk->private_data;
         size_t offset = sector << 9;
@@ -101,7 +101,7 @@ static long pmem_direct_access(struct block_device *bdev, sector_t sector,
                 return -ENODEV;
 
         /* FIXME convert DAX to comprehend that this mapping has a lifetime */
-        *kaddr = (void __force *) pmem->virt_addr + offset;
+        *kaddr = pmem->virt_addr + offset;
         *pfn = (pmem->phys_addr + offset) >> PAGE_SHIFT;
 
         return pmem->size - offset;
diff --git a/drivers/s390/block/dcssblk.c b/drivers/s390/block/dcssblk.c
index da212813f2d5..2c5a397b9f3e 100644
--- a/drivers/s390/block/dcssblk.c
+++ b/drivers/s390/block/dcssblk.c
@@ -29,7 +29,7 @@ static int dcssblk_open(struct block_device *bdev, fmode_t mode);
 static void dcssblk_release(struct gendisk *disk, fmode_t mode);
 static void dcssblk_make_request(struct request_queue *q, struct bio *bio);
 static long dcssblk_direct_access(struct block_device *bdev, sector_t secnum,
-                                 void **kaddr, unsigned long *pfn, long size);
+                         void __pmem **kaddr, unsigned long *pfn, long size);
 
 static char dcssblk_segments[DCSSBLK_PARM_LEN] = "\0";
 
@@ -879,18 +879,20 @@ fail:
 
 static long
 dcssblk_direct_access (struct block_device *bdev, sector_t secnum,
-                        void **kaddr, unsigned long *pfn, long size)
+                        void __pmem **kaddr, unsigned long *pfn, long size)
 {
         struct dcssblk_dev_info *dev_info;
         unsigned long offset, dev_sz;
+        void *addr;
 
         dev_info = bdev->bd_disk->private_data;
         if (!dev_info)
                 return -ENODEV;
         dev_sz = dev_info->end - dev_info->start;
         offset = secnum * 512;
-        *kaddr = (void *) (dev_info->start + offset);
-        *pfn = virt_to_phys(*kaddr) >> PAGE_SHIFT;
+        addr = (void *) (dev_info->start + offset);
+        *pfn = virt_to_phys(addr) >> PAGE_SHIFT;
+        *kaddr = (void __pmem *) addr;
 
         return dev_sz - offset;
 }
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 198243717da5..2345a9870e2c 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -441,7 +441,7 @@ EXPORT_SYMBOL_GPL(bdev_write_page);
  * accessible at this address.
  */
 long bdev_direct_access(struct block_device *bdev, sector_t sector,
-                        void **addr, unsigned long *pfn, long size)
+                        void __pmem **addr, unsigned long *pfn, long size)
 {
         long avail;
         const struct block_device_operations *ops = bdev->bd_disk->fops;
diff --git a/fs/dax.c b/fs/dax.c
index e07fecc93f80..7c634ac797b1 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -35,7 +35,7 @@ int dax_clear_blocks(struct inode *inode, sector_t block, long size)
 
         might_sleep();
         do {
-                void *addr;
+                void __pmem *addr;
                 unsigned long pfn;
                 long count;
 
@@ -47,7 +47,7 @@ int dax_clear_blocks(struct inode *inode, sector_t block, long size)
                         unsigned pgsz = PAGE_SIZE - offset_in_page(addr);
                         if (pgsz > count)
                                 pgsz = count;
-                        clear_pmem((void __pmem *)addr, pgsz);
+                        clear_pmem(addr, pgsz);
                         addr += pgsz;
                         size -= pgsz;
                         count -= pgsz;
@@ -62,7 +62,8 @@ int dax_clear_blocks(struct inode *inode, sector_t block, long size)
 }
 EXPORT_SYMBOL_GPL(dax_clear_blocks);
 
-static long dax_get_addr(struct buffer_head *bh, void **addr, unsigned blkbits)
+static long dax_get_addr(struct buffer_head *bh, void __pmem **addr,
+                unsigned blkbits)
 {
         unsigned long pfn;
         sector_t sector = bh->b_blocknr << (blkbits - 9);
@@ -70,15 +71,15 @@ static long dax_get_addr(struct buffer_head *bh, void **addr, unsigned blkbits)
 }
 
 /* the clear_pmem() calls are ordered by a wmb_pmem() in the caller */
-static void dax_new_buf(void *addr, unsigned size, unsigned first, loff_t pos,
-                        loff_t end)
+static void dax_new_buf(void __pmem *addr, unsigned size, unsigned first,
+                loff_t pos, loff_t end)
 {
         loff_t final = end - pos + first; /* The final byte of the buffer */
 
         if (first > 0)
-                clear_pmem((void __pmem *)addr, first);
+                clear_pmem(addr, first);
         if (final < size)
-                clear_pmem((void __pmem *)addr + final, size - final);
+                clear_pmem(addr + final, size - final);
 }
 
 static bool buffer_written(struct buffer_head *bh)
@@ -106,7 +107,7 @@ static ssize_t dax_io(struct inode *inode, struct iov_iter *iter,
         loff_t pos = start;
         loff_t max = start;
         loff_t bh_max = start;
-        void *addr;
+        void __pmem *addr;
         bool hole = false;
         bool need_wmb = false;
 
@@ -158,11 +159,11 @@ static ssize_t dax_io(struct inode *inode, struct iov_iter *iter,
                 }
 
                 if (iov_iter_rw(iter) == WRITE) {
-                        len = copy_from_iter_pmem((void __pmem *)addr,
-                                        max - pos, iter);
+                        len = copy_from_iter_pmem(addr, max - pos, iter);
                         need_wmb = true;
                 } else if (!hole)
-                        len = copy_to_iter(addr, max - pos, iter);
+                        len = copy_to_iter((void __force *)addr, max - pos,
+                                        iter);
                 else
                         len = iov_iter_zero(max - pos, iter);
 
@@ -268,11 +269,13 @@ static int dax_load_hole(struct address_space *mapping, struct page *page,
 static int copy_user_bh(struct page *to, struct buffer_head *bh,
                         unsigned blkbits, unsigned long vaddr)
 {
-        void *vfrom, *vto;
+        void __pmem *vfrom;
+        void *vto;
+
         if (dax_get_addr(bh, &vfrom, blkbits) < 0)
                 return -EIO;
         vto = kmap_atomic(to);
-        copy_user_page(vto, vfrom, vaddr, to);
+        copy_user_page(vto, (void __force *)vfrom, vaddr, to);
         kunmap_atomic(vto);
         return 0;
 }
@@ -283,7 +286,7 @@ static int dax_insert_mapping(struct inode *inode, struct buffer_head *bh,
         struct address_space *mapping = inode->i_mapping;
         sector_t sector = bh->b_blocknr << (inode->i_blkbits - 9);
         unsigned long vaddr = (unsigned long)vmf->virtual_address;
-        void *addr;
+        void __pmem *addr;
         unsigned long pfn;
         pgoff_t size;
         int error;
@@ -312,7 +315,7 @@ static int dax_insert_mapping(struct inode *inode, struct buffer_head *bh,
         }
 
         if (buffer_unwritten(bh) || buffer_new(bh)) {
-                clear_pmem((void __pmem *)addr, PAGE_SIZE);
+                clear_pmem(addr, PAGE_SIZE);
                 wmb_pmem();
         }
 
@@ -548,11 +551,11 @@ int dax_zero_page_range(struct inode *inode, loff_t from, unsigned length,
         if (err < 0)
                 return err;
         if (buffer_written(&bh)) {
-                void *addr;
+                void __pmem *addr;
                 err = dax_get_addr(&bh, &addr, inode->i_blkbits);
                 if (err < 0)
                         return err;
-                clear_pmem((void __pmem *)addr + offset, length);
+                clear_pmem(addr + offset, length);
                 wmb_pmem();
         }
 
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index d4068c17d0df..c401ecdff9cb 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1555,8 +1555,8 @@ struct block_device_operations {
         int (*rw_page)(struct block_device *, sector_t, struct page *, int rw);
         int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
         int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
-        long (*direct_access)(struct block_device *, sector_t,
-                                        void **, unsigned long *pfn, long size);
+        long (*direct_access)(struct block_device *, sector_t, void __pmem **,
+                        unsigned long *pfn, long size);
         unsigned int (*check_events) (struct gendisk *disk,
                                       unsigned int clearing);
         /* ->media_changed() is DEPRECATED, use ->check_events() instead */
@@ -1574,8 +1574,8 @@ extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int,
 extern int bdev_read_page(struct block_device *, sector_t, struct page *);
 extern int bdev_write_page(struct block_device *, sector_t, struct page *,
                                                 struct writeback_control *);
-extern long bdev_direct_access(struct block_device *, sector_t, void **addr,
-                                                unsigned long *pfn, long size);
+extern long bdev_direct_access(struct block_device *, sector_t,
+                void __pmem **addr, unsigned long *pfn, long size);
 #else /* CONFIG_BLOCK */
 
 struct block_device;