t10-pi: reduce ref tag code duplication

t10_pi_ref_tag() and ext_pi_ref_tag() are identical except for the final
truncation of the ref tag to 32 or 48 bits. Factor out a helper
full_pi_ref_tag() to return the untruncated ref tag and use it in
t10_pi_ref_tag() and ext_pi_ref_tag().

Signed-off-by: Caleb Sander Mateos <[email protected]>
Reviewed-by: Anuj Gupta <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>

Author: calebsander

include/linux/t10-pi.h

@@ -4,6 +4,7 @@
 
 #include <linux/types.h>
 #include <linux/blk-mq.h>
+#include <linux/wordpart.h>
 
 /*
  * A T10 PI-capable target device can be formatted with different
@@ -25,6 +26,16 @@ enum t10_dif_type {
 	T10_PI_TYPE3_PROTECTION = 0x3,
 };
 
+static inline u64 full_pi_ref_tag(const struct request *rq)
+{
+	unsigned int shift = ilog2(queue_logical_block_size(rq->q));
+
+	if (IS_ENABLED(CONFIG_BLK_DEV_INTEGRITY) &&
+	    rq->q->limits.integrity.interval_exp)
+		shift = rq->q->limits.integrity.interval_exp;
+	return blk_rq_pos(rq) >> (shift - SECTOR_SHIFT);
+}
+
 /*
  * T10 Protection Information tuple.
  */
@@ -39,12 +50,7 @@ struct t10_pi_tuple {
 
 static inline u32 t10_pi_ref_tag(struct request *rq)
 {
-	unsigned int shift = ilog2(queue_logical_block_size(rq->q));
-
-	if (IS_ENABLED(CONFIG_BLK_DEV_INTEGRITY) &&
-	    rq->q->limits.integrity.interval_exp)
-		shift = rq->q->limits.integrity.interval_exp;
-	return blk_rq_pos(rq) >> (shift - SECTOR_SHIFT) & 0xffffffff;
+	return lower_32_bits(full_pi_ref_tag(rq));
 }
 
 struct crc64_pi_tuple {
@@ -64,12 +70,7 @@ static inline u64 lower_48_bits(u64 n)
 
 static inline u64 ext_pi_ref_tag(struct request *rq)
 {
-	unsigned int shift = ilog2(queue_logical_block_size(rq->q));
-
-	if (IS_ENABLED(CONFIG_BLK_DEV_INTEGRITY) &&
-	    rq->q->limits.integrity.interval_exp)
-		shift = rq->q->limits.integrity.interval_exp;
-	return lower_48_bits(blk_rq_pos(rq) >> (shift - SECTOR_SHIFT));
+	return lower_48_bits(full_pi_ref_tag(rq));
 }
 
 #endif