[PATCH v3 7/7] pmem, dax: have direct_access use __pmem annotation

From: Ross Zwisler
Date: Mon Aug 17 2015 - 14:32:55 EST

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@xxxxxxxxxxxxxxx>
---
Documentation/filesystems/Locking | 3 ++-
arch/powerpc/sysdev/axonram.c | 7 ++++---
drivers/block/brd.c | 4 ++--
drivers/nvdimm/pmem.c | 4 ++--
drivers/s390/block/dcssblk.c | 10 ++++++----
fs/block_dev.c | 2 +-
fs/dax.c | 42 ++++++++++++++++++++-------------------
include/linux/blkdev.h | 8 ++++----
8 files changed, 43 insertions(+), 37 deletions(-)

diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking
index 6a34a0f..06d4434 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 ee90db1..a2be2a6 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 5750b39..2691bb6 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 ade9eb9..68f6a6a 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 da21281..2c5a397 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 9be2d7e..4ab366d 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -442,7 +442,7 @@ 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 680b44a..3c66303 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -36,7 +36,7 @@ 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;

@@ -48,7 +48,7 @@ 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;
@@ -63,7 +63,8 @@ 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);
@@ -71,15 +72,15 @@ 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)
@@ -107,7 +108,7 @@ 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;

@@ -159,11 +160,11 @@ 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);

@@ -269,11 +270,13 @@ 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,
{
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;
@@ -310,7 +313,7 @@ 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();
}

@@ -525,7 +528,7 @@ int __dax_pmd_fault(struct vm_area_struct *vma, unsigned long address,
unsigned long pmd_addr = address & PMD_MASK;
bool write = flags & FAULT_FLAG_WRITE;
long length;
- void *kaddr;
+ void __pmem *kaddr;
pgoff_t size, pgoff;
sector_t block, sector;
unsigned long pfn;
@@ -619,8 +622,7 @@ int __dax_pmd_fault(struct vm_area_struct *vma, unsigned long address,
if (buffer_unwritten(&bh) || buffer_new(&bh)) {
int i;
for (i = 0; i < PTRS_PER_PMD; i++)
- clear_pmem((void __pmem *)kaddr + i*PAGE_SIZE,
- PAGE_SIZE);
+ clear_pmem(kaddr + i * PAGE_SIZE, PAGE_SIZE);
wmb_pmem();
count_vm_event(PGMAJFAULT);
mem_cgroup_count_vm_event(vma->vm_mm, PGMAJFAULT);
@@ -729,11 +731,11 @@ 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 d4068c1..c401ecd 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;
--
2.1.0

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