[PATCH 13/13] pmem: kill __pmem address space

From: Dan Williams
Date: Sat Jun 04 2016 - 16:54:51 EST


The __pmem address space was meant to annotate codepaths that touch
persistent memory and need to coordinate a call to wmb_pmem(). Now that
wmb_pmem() is gone, there is little need to keep this annotation.

Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx>
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
Documentation/filesystems/Locking | 2 +
arch/powerpc/sysdev/axonram.c | 4 +-
arch/x86/include/asm/pmem.h | 41 +++++++++-------------
drivers/acpi/nfit.c | 3 +-
drivers/acpi/nfit.h | 2 +
drivers/block/brd.c | 4 +-
drivers/nvdimm/pmem.c | 8 ++--
drivers/s390/block/dcssblk.c | 6 ++-
fs/dax.c | 6 ++-
include/linux/blkdev.h | 6 ++-
include/linux/compiler.h | 2 -
include/linux/nd.h | 2 +
include/linux/pmem.h | 70 +++++++++----------------------------
scripts/checkpatch.pl | 1 -
14 files changed, 55 insertions(+), 102 deletions(-)

diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking
index 75eea7ce3d7c..d9c37ec4c760 100644
--- a/Documentation/filesystems/Locking
+++ b/Documentation/filesystems/Locking
@@ -395,7 +395,7 @@ 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 __pmem **,
+ int (*direct_access) (struct block_device *, sector_t, void **,
unsigned long *);
int (*media_changed) (struct gendisk *);
void (*unlock_native_capacity) (struct gendisk *);
diff --git a/arch/powerpc/sysdev/axonram.c b/arch/powerpc/sysdev/axonram.c
index ff75d70f7285..154cd9110c08 100644
--- a/arch/powerpc/sysdev/axonram.c
+++ b/arch/powerpc/sysdev/axonram.c
@@ -143,12 +143,12 @@ 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 __pmem **kaddr, pfn_t *pfn, long size)
+ void **kaddr, pfn_t *pfn, long size)
{
struct axon_ram_bank *bank = device->bd_disk->private_data;
loff_t offset = (loff_t)sector << AXON_RAM_SECTOR_SHIFT;

- *kaddr = (void __pmem __force *) bank->io_addr + offset;
+ *kaddr = bank->io_addr + offset;
*pfn = phys_to_pfn_t(bank->ph_addr + offset, PFN_DEV);
return bank->size - offset;
}
diff --git a/arch/x86/include/asm/pmem.h b/arch/x86/include/asm/pmem.h
index a8cf2a6b14d9..643eba42d620 100644
--- a/arch/x86/include/asm/pmem.h
+++ b/arch/x86/include/asm/pmem.h
@@ -28,10 +28,9 @@
* Copy data to persistent memory media via non-temporal stores so that
* a subsequent pmem driver flush operation will drain posted write queues.
*/
-static inline void arch_memcpy_to_pmem(void __pmem *dst, const void *src,
- size_t n)
+static inline void arch_memcpy_to_pmem(void *dst, const void *src, size_t n)
{
- int unwritten;
+ int rem;

/*
* We are copying between two kernel buffers, if
@@ -39,19 +38,17 @@ static inline void arch_memcpy_to_pmem(void __pmem *dst, const void *src,
* fault) we would have already reported a general protection fault
* before the WARN+BUG.
*/
- unwritten = __copy_from_user_inatomic_nocache((void __force *) dst,
- (void __user *) src, n);
- if (WARN(unwritten, "%s: fault copying %p <- %p unwritten: %d\n",
- __func__, dst, src, unwritten))
+ rem = __copy_from_user_inatomic_nocache(dst, (void __user *) src, n);
+ if (WARN(rem, "%s: fault copying %p <- %p unwritten: %d\n",
+ __func__, dst, src, rem))
BUG();
}

-static inline int arch_memcpy_from_pmem(void *dst, const void __pmem *src,
- size_t n)
+static inline int arch_memcpy_from_pmem(void *dst, const void *src, size_t n)
{
if (static_cpu_has(X86_FEATURE_MCE_RECOVERY))
- return memcpy_mcsafe(dst, (void __force *) src, n);
- memcpy(dst, (void __force *) src, n);
+ return memcpy_mcsafe(dst, src, n);
+ memcpy(dst, src, n);
return 0;
}

@@ -63,15 +60,14 @@ static inline int arch_memcpy_from_pmem(void *dst, const void __pmem *src,
* Write back a cache range using the CLWB (cache line write back)
* instruction.
*/
-static inline void arch_wb_cache_pmem(void __pmem *addr, size_t size)
+static inline void arch_wb_cache_pmem(void *addr, size_t size)
{
u16 x86_clflush_size = boot_cpu_data.x86_clflush_size;
unsigned long clflush_mask = x86_clflush_size - 1;
- void *vaddr = (void __force *)addr;
- void *vend = vaddr + size;
+ void *vend = addr + size;
void *p;

- for (p = (void *)((unsigned long)vaddr & ~clflush_mask);
+ for (p = (void *)((unsigned long)addr & ~clflush_mask);
p < vend; p += x86_clflush_size)
clwb(p);
}
@@ -93,14 +89,13 @@ static inline bool __iter_needs_pmem_wb(struct iov_iter *i)
*
* Copy data from the iterator 'i' to the PMEM buffer starting at 'addr'.
*/
-static inline size_t arch_copy_from_iter_pmem(void __pmem *addr, size_t bytes,
+static inline size_t arch_copy_from_iter_pmem(void *addr, size_t bytes,
struct iov_iter *i)
{
- void *vaddr = (void __force *)addr;
size_t len;

/* TODO: skip the write-back by always using non-temporal stores */
- len = copy_from_iter_nocache(vaddr, bytes, i);
+ len = copy_from_iter_nocache(addr, bytes, i);

if (__iter_needs_pmem_wb(i))
arch_wb_cache_pmem(addr, bytes);
@@ -115,17 +110,15 @@ static inline size_t arch_copy_from_iter_pmem(void __pmem *addr, size_t bytes,
*
* Write zeros into the memory range starting at 'addr' for 'size' bytes.
*/
-static inline void arch_clear_pmem(void __pmem *addr, size_t size)
+static inline void arch_clear_pmem(void *addr, size_t size)
{
- void *vaddr = (void __force *)addr;
-
- memset(vaddr, 0, size);
+ memset(addr, 0, size);
arch_wb_cache_pmem(addr, size);
}

-static inline void arch_invalidate_pmem(void __pmem *addr, size_t size)
+static inline void arch_invalidate_pmem(void *addr, size_t size)
{
- clflush_cache_range((void __force *) addr, size);
+ clflush_cache_range(addr, size);
}
#endif /* CONFIG_ARCH_HAS_PMEM_API */
#endif /* __ASM_X86_PMEM_H__ */
diff --git a/drivers/acpi/nfit.c b/drivers/acpi/nfit.c
index 4643dd7a4284..2b556c084576 100644
--- a/drivers/acpi/nfit.c
+++ b/drivers/acpi/nfit.c
@@ -1612,8 +1612,7 @@ static void __iomem *__nfit_spa_map(struct acpi_nfit_desc *acpi_desc,

spa_map->type = type;
if (type == SPA_MAP_APERTURE)
- spa_map->addr.aperture = (void __pmem *)memremap(start, n,
- ARCH_MEMREMAP_PMEM);
+ spa_map->addr.aperture = memremap(start, n, ARCH_MEMREMAP_PMEM);
else
spa_map->addr.base = ioremap_nocache(start, n);

diff --git a/drivers/acpi/nfit.h b/drivers/acpi/nfit.h
index 9c8a6cf760be..626b107c6d6c 100644
--- a/drivers/acpi/nfit.h
+++ b/drivers/acpi/nfit.h
@@ -161,7 +161,7 @@ enum nd_blk_mmio_selector {
struct nd_blk_addr {
union {
void __iomem *base;
- void __pmem *aperture;
+ void *aperture;
};
};

diff --git a/drivers/block/brd.c b/drivers/block/brd.c
index c04bd9bc39fd..5f1fe4e6208d 100644
--- a/drivers/block/brd.c
+++ b/drivers/block/brd.c
@@ -381,7 +381,7 @@ 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 __pmem **kaddr, pfn_t *pfn, long size)
+ void **kaddr, pfn_t *pfn, long size)
{
struct brd_device *brd = bdev->bd_disk->private_data;
struct page *page;
@@ -391,7 +391,7 @@ static long brd_direct_access(struct block_device *bdev, sector_t sector,
page = brd_insert_page(brd, sector);
if (!page)
return -ENOSPC;
- *kaddr = (void __pmem *)page_address(page);
+ *kaddr = page_address(page);
*pfn = page_to_pfn_t(page);

return PAGE_SIZE;
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index 79539b6498c9..fd645585b71d 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -38,7 +38,7 @@ struct pmem_device {
/* when non-zero this device is hosting a 'pfn' instance */
phys_addr_t data_offset;
u64 pfn_flags;
- void __pmem *virt_addr;
+ void *virt_addr;
/* immutable base size of the namespace */
size_t size;
/* trim size when namespace capacity has been section aligned */
@@ -87,7 +87,7 @@ static int pmem_do_bvec(struct pmem_device *pmem, struct page *page,
bool bad_pmem = false;
void *mem = kmap_atomic(page);
phys_addr_t pmem_off = sector * 512 + pmem->data_offset;
- void __pmem *pmem_addr = pmem->virt_addr + pmem_off;
+ void *pmem_addr = pmem->virt_addr + pmem_off;

if (unlikely(is_bad_pmem(&pmem->bb, sector, len)))
bad_pmem = true;
@@ -176,7 +176,7 @@ 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 __pmem **kaddr, pfn_t *pfn, long size)
+ void **kaddr, pfn_t *pfn, long size)
{
struct pmem_device *pmem = bdev->bd_queue->queuedata;
resource_size_t offset = sector * 512 + pmem->data_offset;
@@ -287,7 +287,7 @@ static int pmem_attach_disk(struct device *dev,

if (IS_ERR(addr))
return PTR_ERR(addr);
- pmem->virt_addr = (void __pmem *) addr;
+ pmem->virt_addr = addr;

has_flush = nvdimm_has_flush(nd_region);
if (has_flush < 0)
diff --git a/drivers/s390/block/dcssblk.c b/drivers/s390/block/dcssblk.c
index bed53c46dd90..ac0345bedd9d 100644
--- a/drivers/s390/block/dcssblk.c
+++ b/drivers/s390/block/dcssblk.c
@@ -31,7 +31,7 @@ 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,
- void __pmem **kaddr, pfn_t *pfn, long size);
+ void **kaddr, pfn_t *pfn, long size);

static char dcssblk_segments[DCSSBLK_PARM_LEN] = "\0";

@@ -884,7 +884,7 @@ fail:

static long
dcssblk_direct_access (struct block_device *bdev, sector_t secnum,
- void __pmem **kaddr, pfn_t *pfn, long size)
+ void **kaddr, pfn_t *pfn, long size)
{
struct dcssblk_dev_info *dev_info;
unsigned long offset, dev_sz;
@@ -894,7 +894,7 @@ dcssblk_direct_access (struct block_device *bdev, sector_t secnum,
return -ENODEV;
dev_sz = dev_info->end - dev_info->start;
offset = secnum * 512;
- *kaddr = (void __pmem *) (dev_info->start + offset);
+ *kaddr = dev_info->start + offset;
*pfn = __pfn_to_pfn_t(PFN_DOWN(dev_info->start + offset), PFN_DEV);

return dev_sz - offset;
diff --git a/fs/dax.c b/fs/dax.c
index 434f421da660..c8312f6441bc 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -75,13 +75,13 @@ static long dax_map_atomic(struct block_device *bdev, struct blk_dax_ctl *dax)
struct request_queue *q = bdev->bd_queue;
long rc = -EIO;

- dax->addr = (void __pmem *) ERR_PTR(-EIO);
+ dax->addr = ERR_PTR(-EIO);
if (blk_queue_enter(q, true) != 0)
return rc;

rc = bdev_direct_access(bdev, dax);
if (rc < 0) {
- dax->addr = (void __pmem *) ERR_PTR(rc);
+ dax->addr = ERR_PTR(rc);
blk_queue_exit(q);
return rc;
}
@@ -152,7 +152,7 @@ static ssize_t dax_io(struct inode *inode, struct iov_iter *iter,
int rw = iov_iter_rw(iter), rc;
long map_len = 0;
struct blk_dax_ctl dax = {
- .addr = (void __pmem *) ERR_PTR(-EIO),
+ .addr = ERR_PTR(-EIO),
};
unsigned blkbits = inode->i_blkbits;
sector_t file_blks = (i_size_read(inode) + (1 << blkbits) - 1)
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 3d9cf326574f..fde908b2836b 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1659,7 +1659,7 @@ static inline bool integrity_req_gap_front_merge(struct request *req,
*/
struct blk_dax_ctl {
sector_t sector;
- void __pmem *addr;
+ void *addr;
long size;
pfn_t pfn;
};
@@ -1670,8 +1670,8 @@ 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 __pmem **,
- pfn_t *, long);
+ long (*direct_access)(struct block_device *, sector_t, void **, pfn_t *,
+ long);
unsigned int (*check_events) (struct gendisk *disk,
unsigned int clearing);
/* ->media_changed() is DEPRECATED, use ->check_events() instead */
diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index 793c0829e3a3..b966974938ed 100644
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -17,7 +17,6 @@
# define __release(x) __context__(x,-1)
# define __cond_lock(x,c) ((c) ? ({ __acquire(x); 1; }) : 0)
# define __percpu __attribute__((noderef, address_space(3)))
-# define __pmem __attribute__((noderef, address_space(5)))
#ifdef CONFIG_SPARSE_RCU_POINTER
# define __rcu __attribute__((noderef, address_space(4)))
#else /* CONFIG_SPARSE_RCU_POINTER */
@@ -45,7 +44,6 @@ extern void __chk_io_ptr(const volatile void __iomem *);
# define __cond_lock(x,c) (c)
# define __percpu
# define __rcu
-# define __pmem
# define __private
# define ACCESS_PRIVATE(p, member) ((p)->member)
#endif /* __CHECKER__ */
diff --git a/include/linux/nd.h b/include/linux/nd.h
index aee2761d294c..47271d366be5 100644
--- a/include/linux/nd.h
+++ b/include/linux/nd.h
@@ -67,7 +67,7 @@ struct nd_namespace_io {
struct nd_namespace_common common;
struct resource res;
resource_size_t size;
- void __pmem *addr;
+ void *addr;
struct badblocks bb;
};

diff --git a/include/linux/pmem.h b/include/linux/pmem.h
index 9e3ea94b8157..e856c2cb0fe8 100644
--- a/include/linux/pmem.h
+++ b/include/linux/pmem.h
@@ -26,37 +26,35 @@
* calling these symbols with arch_has_pmem_api() and redirect to the
* implementation in asm/pmem.h.
*/
-static inline void arch_memcpy_to_pmem(void __pmem *dst, const void *src,
- size_t n)
+static inline void arch_memcpy_to_pmem(void *dst, const void *src, size_t n)
{
BUG();
}

-static inline int arch_memcpy_from_pmem(void *dst, const void __pmem *src,
- size_t n)
+static inline int arch_memcpy_from_pmem(void *dst, const void *src, size_t n)
{
BUG();
return -EFAULT;
}

-static inline size_t arch_copy_from_iter_pmem(void __pmem *addr, size_t bytes,
+static inline size_t arch_copy_from_iter_pmem(void *addr, size_t bytes,
struct iov_iter *i)
{
BUG();
return 0;
}

-static inline void arch_clear_pmem(void __pmem *addr, size_t size)
+static inline void arch_clear_pmem(void *addr, size_t size)
{
BUG();
}

-static inline void arch_wb_cache_pmem(void __pmem *addr, size_t size)
+static inline void arch_wb_cache_pmem(void *addr, size_t size)
{
BUG();
}

-static inline void arch_invalidate_pmem(void __pmem *addr, size_t size)
+static inline void arch_invalidate_pmem(void *addr, size_t size)
{
BUG();
}
@@ -67,13 +65,6 @@ static inline bool arch_has_pmem_api(void)
return IS_ENABLED(CONFIG_ARCH_HAS_PMEM_API);
}

-static inline int default_memcpy_from_pmem(void *dst, void __pmem const *src,
- size_t size)
-{
- memcpy(dst, (void __force *) src, size);
- return 0;
-}
-
/*
* memcpy_from_pmem - read from persistent memory with error handling
* @dst: destination buffer
@@ -82,40 +73,13 @@ static inline int default_memcpy_from_pmem(void *dst, void __pmem const *src,
*
* Returns 0 on success negative error code on failure.
*/
-static inline int memcpy_from_pmem(void *dst, void __pmem const *src,
- size_t size)
+static inline int memcpy_from_pmem(void *dst, void const *src, size_t size)
{
if (arch_has_pmem_api())
return arch_memcpy_from_pmem(dst, src, size);
else
- return default_memcpy_from_pmem(dst, src, size);
-}
-
-/*
- * These defaults seek to offer decent performance and minimize the
- * window between i/o completion and writes being durable on media.
- * However, it is undefined / architecture specific whether
- * ARCH_MEMREMAP_PMEM + default_memcpy_to_pmem is sufficient for
- * making data durable relative to i/o completion.
- */
-static inline void default_memcpy_to_pmem(void __pmem *dst, const void *src,
- size_t size)
-{
- memcpy((void __force *) dst, src, size);
-}
-
-static inline size_t default_copy_from_iter_pmem(void __pmem *addr,
- size_t bytes, struct iov_iter *i)
-{
- return copy_from_iter_nocache((void __force *)addr, bytes, i);
-}
-
-static inline void default_clear_pmem(void __pmem *addr, size_t size)
-{
- if (size == PAGE_SIZE && ((unsigned long)addr & ~PAGE_MASK) == 0)
- clear_page((void __force *)addr);
- else
- memset((void __force *)addr, 0, size);
+ memcpy(dst, src, size);
+ return 0;
}

/**
@@ -130,12 +94,12 @@ static inline void default_clear_pmem(void __pmem *addr, size_t size)
* data may still reside in cpu or platform buffers, so this operation
* must be followed by a blkdev_issue_flush() on the pmem block device.
*/
-static inline void memcpy_to_pmem(void __pmem *dst, const void *src, size_t n)
+static inline void memcpy_to_pmem(void *dst, const void *src, size_t n)
{
if (arch_has_pmem_api())
arch_memcpy_to_pmem(dst, src, n);
else
- default_memcpy_to_pmem(dst, src, n);
+ memcpy(dst, src, n);
}

/**
@@ -147,12 +111,12 @@ static inline void memcpy_to_pmem(void __pmem *dst, const void *src, size_t n)
* Copy data from the iterator 'i' to the PMEM buffer starting at 'addr'.
* See blkdev_issue_flush() note for memcpy_to_pmem().
*/
-static inline size_t copy_from_iter_pmem(void __pmem *addr, size_t bytes,
+static inline size_t copy_from_iter_pmem(void *addr, size_t bytes,
struct iov_iter *i)
{
if (arch_has_pmem_api())
return arch_copy_from_iter_pmem(addr, bytes, i);
- return default_copy_from_iter_pmem(addr, bytes, i);
+ return copy_from_iter_nocache(addr, bytes, i);
}

/**
@@ -163,12 +127,12 @@ static inline size_t copy_from_iter_pmem(void __pmem *addr, size_t bytes,
* Write zeros into the memory range starting at 'addr' for 'size' bytes.
* See blkdev_issue_flush() note for memcpy_to_pmem().
*/
-static inline void clear_pmem(void __pmem *addr, size_t size)
+static inline void clear_pmem(void *addr, size_t size)
{
if (arch_has_pmem_api())
arch_clear_pmem(addr, size);
else
- default_clear_pmem(addr, size);
+ memset(addr, 0, size);
}

/**
@@ -179,7 +143,7 @@ static inline void clear_pmem(void __pmem *addr, size_t size)
* For platforms that support clearing poison this flushes any poisoned
* ranges out of the cache
*/
-static inline void invalidate_pmem(void __pmem *addr, size_t size)
+static inline void invalidate_pmem(void *addr, size_t size)
{
if (arch_has_pmem_api())
arch_invalidate_pmem(addr, size);
@@ -193,7 +157,7 @@ static inline void invalidate_pmem(void __pmem *addr, size_t size)
* Write back the processor cache range starting at 'addr' for 'size' bytes.
* See blkdev_issue_flush() note for memcpy_to_pmem().
*/
-static inline void wb_cache_pmem(void __pmem *addr, size_t size)
+static inline void wb_cache_pmem(void *addr, size_t size)
{
if (arch_has_pmem_api())
arch_wb_cache_pmem(addr, size);
diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 6750595bd7b8..32f01a1a28bb 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -313,7 +313,6 @@ our $Sparse = qr{
__kernel|
__force|
__iomem|
- __pmem|
__must_check|
__init_refok|
__kprobes|