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authorRoss Zwisler <ross.zwisler@linux.intel.com>2015-08-18 13:55:39 -0600
committerDan Williams <dan.j.williams@intel.com>2015-08-20 14:07:23 -0400
commit5de490daec8b6354b90d5c9d3e2415b195f5adb6 (patch)
tree0f9091d0827916e8a810cff47315445bed81d726 /include/linux/pmem.h
parent4a370df5534ef727cba9a9d74bf22e0609f91d6e (diff)
pmem: add copy_from_iter_pmem() and clear_pmem()
Add support for two new PMEM APIs, copy_from_iter_pmem() and clear_pmem(). copy_from_iter_pmem() is used to copy data from an iterator into a PMEM buffer. clear_pmem() zeros a PMEM memory range. Both of these new APIs must be explicitly ordered using a wmb_pmem() function call and are implemented in such a way that the wmb_pmem() will make the stores to PMEM durable. Because both APIs are unordered they can be called as needed without introducing any unwanted memory barriers. Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'include/linux/pmem.h')
-rw-r--r--include/linux/pmem.h64
1 files changed, 62 insertions, 2 deletions
diff --git a/include/linux/pmem.h b/include/linux/pmem.h
index a0706ea04efd..a9d84bf335ee 100644
--- a/include/linux/pmem.h
+++ b/include/linux/pmem.h
@@ -14,6 +14,7 @@
#define __PMEM_H__
#include <linux/io.h>
+#include <linux/uio.h>
#ifdef CONFIG_ARCH_HAS_PMEM_API
#include <asm/pmem.h>
@@ -33,12 +34,24 @@ static inline void arch_memcpy_to_pmem(void __pmem *dst, const void *src,
{
BUG();
}
+
+static inline size_t arch_copy_from_iter_pmem(void __pmem *addr, size_t bytes,
+ struct iov_iter *i)
+{
+ BUG();
+ return 0;
+}
+
+static inline void arch_clear_pmem(void __pmem *addr, size_t size)
+{
+ BUG();
+}
#endif
/*
* Architectures that define ARCH_HAS_PMEM_API must provide
- * implementations for arch_memcpy_to_pmem(), arch_wmb_pmem(), and
- * arch_has_wmb_pmem().
+ * implementations for arch_memcpy_to_pmem(), arch_wmb_pmem(),
+ * arch_copy_from_iter_pmem(), arch_clear_pmem() and arch_has_wmb_pmem().
*/
static inline void memcpy_from_pmem(void *dst, void __pmem const *src, size_t size)
@@ -78,6 +91,20 @@ static inline void default_memcpy_to_pmem(void __pmem *dst, const void *src,
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);
+}
+
/**
* memremap_pmem - map physical persistent memory for pmem api
* @offset: physical address of persistent memory
@@ -134,4 +161,37 @@ static inline void wmb_pmem(void)
if (arch_has_pmem_api())
arch_wmb_pmem();
}
+
+/**
+ * copy_from_iter_pmem - copy data from an iterator to PMEM
+ * @addr: PMEM destination address
+ * @bytes: number of bytes to copy
+ * @i: iterator with source data
+ *
+ * Copy data from the iterator 'i' to the PMEM buffer starting at 'addr'.
+ * This function requires explicit ordering with a wmb_pmem() call.
+ */
+static inline size_t copy_from_iter_pmem(void __pmem *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);
+}
+
+/**
+ * clear_pmem - zero a PMEM memory range
+ * @addr: virtual start address
+ * @size: number of bytes to zero
+ *
+ * Write zeros into the memory range starting at 'addr' for 'size' bytes.
+ * This function requires explicit ordering with a wmb_pmem() call.
+ */
+static inline void clear_pmem(void __pmem *addr, size_t size)
+{
+ if (arch_has_pmem_api())
+ arch_clear_pmem(addr, size);
+ else
+ default_clear_pmem(addr, size);
+}
#endif /* __PMEM_H__ */