lib: packing: use BITS_PER_BYTE instead of 8

JIRA: https://issues.redhat.com/browse/RHEL-92666

Upstream commit(s):
commit fb02c7c
Author: Vladimir Oltean <vladimir.oltean@nxp.com>
Date:   Wed Oct 2 14:51:58 2024 -0700

    lib: packing: use BITS_PER_BYTE instead of 8

    This helps clarify what the 8 is for.

    Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
    Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
    Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
    Link: https://patch.msgid.link/20241002-packing-kunit-tests-and-split-pack-unpack-v2-9-8373e551eae3@intel.com
    Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Signed-off-by: Petr Oros <poros@redhat.com>

Author: orosp

lib/packing.c

@@ -83,7 +83,7 @@ int pack(void *pbuf, u64 uval, size_t startbit, size_t endbit, size_t pbuflen,
 	/* startbit is expected to be larger than endbit, and both are
 	 * expected to be within the logically addressable range of the buffer.
 	 */
-	if (unlikely(startbit < endbit || startbit >= 8 * pbuflen))
+	if (unlikely(startbit < endbit || startbit >= BITS_PER_BYTE * pbuflen))
 		/* Invalid function call */
 		return -EINVAL;
 
@@ -106,8 +106,8 @@ int pack(void *pbuf, u64 uval, size_t startbit, size_t endbit, size_t pbuflen,
 	 * no quirks, u8 by u8 (aligned at u8 boundaries), from high to low
 	 * logical bit significance. "box" denotes the current logical u8.
 	 */
-	plogical_first_u8 = startbit / 8;
-	plogical_last_u8  = endbit / 8;
+	plogical_first_u8 = startbit / BITS_PER_BYTE;
+	plogical_last_u8  = endbit / BITS_PER_BYTE;
 
 	for (box = plogical_first_u8; box >= plogical_last_u8; box--) {
 		/* Bit indices into the currently accessed 8-bit box */
@@ -123,11 +123,11 @@ int pack(void *pbuf, u64 uval, size_t startbit, size_t endbit, size_t pbuflen,
 		 * input arguments startbit and endbit.
 		 */
 		if (box == plogical_first_u8)
-			box_start_bit = startbit % 8;
+			box_start_bit = startbit % BITS_PER_BYTE;
 		else
 			box_start_bit = 7;
 		if (box == plogical_last_u8)
-			box_end_bit = endbit % 8;
+			box_end_bit = endbit % BITS_PER_BYTE;
 		else
 			box_end_bit = 0;
 
@@ -138,8 +138,8 @@ int pack(void *pbuf, u64 uval, size_t startbit, size_t endbit, size_t pbuflen,
 		 * box is u8, the projection is u64 because it may fall
 		 * anywhere within the unpacked u64.
 		 */
-		proj_start_bit = ((box * 8) + box_start_bit) - endbit;
-		proj_end_bit   = ((box * 8) + box_end_bit) - endbit;
+		proj_start_bit = ((box * BITS_PER_BYTE) + box_start_bit) - endbit;
+		proj_end_bit = ((box * BITS_PER_BYTE) + box_end_bit) - endbit;
 		proj_mask = GENMASK_ULL(proj_start_bit, proj_end_bit);
 		box_mask  = GENMASK_ULL(box_start_bit, box_end_bit);
 
@@ -199,7 +199,7 @@ int unpack(const void *pbuf, u64 *uval, size_t startbit, size_t endbit,
 	/* startbit is expected to be larger than endbit, and both are
 	 * expected to be within the logically addressable range of the buffer.
 	 */
-	if (unlikely(startbit < endbit || startbit >= 8 * pbuflen))
+	if (unlikely(startbit < endbit || startbit >= BITS_PER_BYTE * pbuflen))
 		/* Invalid function call */
 		return -EINVAL;
 
@@ -214,8 +214,8 @@ int unpack(const void *pbuf, u64 *uval, size_t startbit, size_t endbit,
 	 * no quirks, u8 by u8 (aligned at u8 boundaries), from high to low
 	 * logical bit significance. "box" denotes the current logical u8.
 	 */
-	plogical_first_u8 = startbit / 8;
-	plogical_last_u8  = endbit / 8;
+	plogical_first_u8 = startbit / BITS_PER_BYTE;
+	plogical_last_u8  = endbit / BITS_PER_BYTE;
 
 	for (box = plogical_first_u8; box >= plogical_last_u8; box--) {
 		/* Bit indices into the currently accessed 8-bit box */
@@ -231,11 +231,11 @@ int unpack(const void *pbuf, u64 *uval, size_t startbit, size_t endbit,
 		 * input arguments startbit and endbit.
 		 */
 		if (box == plogical_first_u8)
-			box_start_bit = startbit % 8;
+			box_start_bit = startbit % BITS_PER_BYTE;
 		else
 			box_start_bit = 7;
 		if (box == plogical_last_u8)
-			box_end_bit = endbit % 8;
+			box_end_bit = endbit % BITS_PER_BYTE;
 		else
 			box_end_bit = 0;
 
@@ -246,8 +246,8 @@ int unpack(const void *pbuf, u64 *uval, size_t startbit, size_t endbit,
 		 * box is u8, the projection is u64 because it may fall
 		 * anywhere within the unpacked u64.
 		 */
-		proj_start_bit = ((box * 8) + box_start_bit) - endbit;
-		proj_end_bit   = ((box * 8) + box_end_bit) - endbit;
+		proj_start_bit = ((box * BITS_PER_BYTE) + box_start_bit) - endbit;
+		proj_end_bit = ((box * BITS_PER_BYTE) + box_end_bit) - endbit;
 		proj_mask = GENMASK_ULL(proj_start_bit, proj_end_bit);
 		box_mask  = GENMASK_ULL(box_start_bit, box_end_bit);