pmem: reduce kmap_atomic sections to the memcpys only

[cascardo/linux.git] / drivers / nvdimm / pmem.c

diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index 571a6c7..42b3a82 100644 (file)
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -66,13 +66,32 @@ static void pmem_clear_poison(struct pmem_device *pmem, phys_addr_t offset,
        invalidate_pmem(pmem->virt_addr + offset, len);
 }
 
+static void write_pmem(void *pmem_addr, struct page *page,
+               unsigned int off, unsigned int len)
+{
+       void *mem = kmap_atomic(page);
+
+       memcpy_to_pmem(pmem_addr, mem + off, len);
+       kunmap_atomic(mem);
+}
+
+static int read_pmem(struct page *page, unsigned int off,
+               void *pmem_addr, unsigned int len)
+{
+       int rc;
+       void *mem = kmap_atomic(page);
+
+       rc = memcpy_from_pmem(mem + off, pmem_addr, len);
+       kunmap_atomic(mem);
+       return rc;
+}
+
 static int pmem_do_bvec(struct pmem_device *pmem, struct page *page,
                        unsigned int len, unsigned int off, bool is_write,
                        sector_t sector)
 {
        int rc = 0;
        bool bad_pmem = false;
-       void *mem = kmap_atomic(page);
        phys_addr_t pmem_off = sector * 512 + pmem->data_offset;
        void *pmem_addr = pmem->virt_addr + pmem_off;
 
@@ -83,7 +102,7 @@ static int pmem_do_bvec(struct pmem_device *pmem, struct page *page,
                if (unlikely(bad_pmem))
                        rc = -EIO;
                else {
-                       rc = memcpy_from_pmem(mem + off, pmem_addr, len);
+                       rc = read_pmem(page, off, pmem_addr, len);
                        flush_dcache_page(page);
                }
        } else {
@@ -102,14 +121,13 @@ static int pmem_do_bvec(struct pmem_device *pmem, struct page *page,
                 * after clear poison.
                 */
                flush_dcache_page(page);
-               memcpy_to_pmem(pmem_addr, mem + off, len);
+               write_pmem(pmem_addr, page, off, len);
                if (unlikely(bad_pmem)) {
                        pmem_clear_poison(pmem, pmem_off, len);
-                       memcpy_to_pmem(pmem_addr, mem + off, len);
+                       write_pmem(pmem_addr, page, off, len);
                }
        }
 
-       kunmap_atomic(mem);
        return rc;
 }