pmem: reduce kmap_atomic sections to the memcpys only
pmem_do_bvec used to kmap_atomic at the begin, and only unmap at the
end. Things like nvdimm_clear_poison may want to do nvdimm subsystem
bookkeeping operations that may involve taking locks or doing memory
allocations, and we can't do that from the atomic context. Reduce the
atomic context to just what needs it - the memcpy to/from pmem.
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index 571a6c7e..42b3a821 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -66,13 +66,32 @@
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 @@
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 @@
* 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;
}