libnvdimm: add an atomic vs process context flag to rw_bytes

nsio_rw_bytes can clear media errors, but this cannot be done while we
are in an atomic context due to locking within ACPI. From the BTT,
->rw_bytes may be called either from atomic or process context depending
on whether the calls happen during initialization or during IO.

During init, we want to ensure error clearing happens, and the flag
marking process context allows nsio_rw_bytes to do that. When called
during IO, we're in atomic context, and error clearing can be skipped.

Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

1 files changed, 7 insertions, 5 deletions

diff --git a/include/linux/nd.h b/include/linux/nd.h
index fa66aeed441a..194b8e002ea7 100644
--- a/include/linux/nd.h
+++ b/include/linux/nd.h
@@ -48,7 +48,7 @@ struct nd_namespace_common {
 	struct device dev;
 	struct device *claim;
 	int (*rw_bytes)(struct nd_namespace_common *, resource_size_t offset,
-			void *buf, size_t size, int rw);
+			void *buf, size_t size, int rw, unsigned long flags);
 };
 
 static inline struct nd_namespace_common *to_ndns(struct device *dev)
@@ -134,9 +134,10 @@ static inline struct nd_namespace_blk *to_nd_namespace_blk(const struct device *
  * @buf is up-to-date upon return from this routine.
  */
 static inline int nvdimm_read_bytes(struct nd_namespace_common *ndns,
-		resource_size_t offset, void *buf, size_t size)
+		resource_size_t offset, void *buf, size_t size,
+		unsigned long flags)
 {
-	return ndns->rw_bytes(ndns, offset, buf, size, READ);
+	return ndns->rw_bytes(ndns, offset, buf, size, READ, flags);
 }
 
 /**
@@ -152,9 +153,10 @@ static inline int nvdimm_read_bytes(struct nd_namespace_common *ndns,
  * to media is handled internal to the @ndns driver, if at all.
  */
 static inline int nvdimm_write_bytes(struct nd_namespace_common *ndns,
-		resource_size_t offset, void *buf, size_t size)
+		resource_size_t offset, void *buf, size_t size,
+		unsigned long flags)
 {
-	return ndns->rw_bytes(ndns, offset, buf, size, WRITE);
+	return ndns->rw_bytes(ndns, offset, buf, size, WRITE, flags);
 }
 
 #define MODULE_ALIAS_ND_DEVICE(type) \