@@ -51,64 +51,20 @@ static size_t calculate_box_addr(size_t box, size_t len, u8 quirks)
return offset_of_group + offset_in_group;
}
-/**
- * pack - Pack u64 number into bitfield of buffer.
- *
- * @pbuf: Pointer to a buffer holding the packed value.
- * @uval: CPU-readable unpacked value to pack.
- * @startbit: The index (in logical notation, compensated for quirks) where
- * the packed value starts within pbuf. Must be larger than, or
- * equal to, endbit.
- * @endbit: The index (in logical notation, compensated for quirks) where
- * the packed value ends within pbuf. Must be smaller than, or equal
- * to, startbit.
- * @pbuflen: The length in bytes of the packed buffer pointed to by @pbuf.
- * @quirks: A bit mask of QUIRK_LITTLE_ENDIAN, QUIRK_LSW32_IS_FIRST and
- * QUIRK_MSB_ON_THE_RIGHT.
- *
- * Return: 0 on success, EINVAL or ERANGE if called incorrectly. Assuming
- * correct usage, return code may be discarded. The @pbuf memory will
- * be modified on success.
- */
-int pack(void *pbuf, u64 uval, size_t startbit, size_t endbit, size_t pbuflen,
- u8 quirks)
+static void __pack(void *pbuf, u64 uval, size_t startbit, size_t endbit,
+ size_t pbuflen, u8 quirks)
{
/* Logical byte indices corresponding to the
* start and end of the field.
*/
- int plogical_first_u8, plogical_last_u8, box;
- /* width of the field to access in the pbuf */
- u64 value_width;
-
- /* 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 >= BITS_PER_BYTE * pbuflen))
- /* Invalid function call */
- return -EINVAL;
-
- value_width = startbit - endbit + 1;
- if (unlikely(value_width > 64))
- return -ERANGE;
-
- /* Check if "uval" fits in "value_width" bits.
- * If value_width is 64, the check will fail, but any
- * 64-bit uval will surely fit.
- */
- if (unlikely(value_width < 64 && uval >= (1ull << value_width)))
- /* Cannot store "uval" inside "value_width" bits.
- * Truncating "uval" is most certainly not desirable,
- * so simply erroring out is appropriate.
- */
- return -ERANGE;
+ int plogical_first_u8 = startbit / BITS_PER_BYTE;
+ int plogical_last_u8 = endbit / BITS_PER_BYTE;
+ int box;
/* Iterate through an idealistic view of the pbuf as an u64 with
* 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 / 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 */
size_t box_start_bit, box_end_bit, box_addr;
@@ -163,15 +119,13 @@ int pack(void *pbuf, u64 uval, size_t startbit, size_t endbit, size_t pbuflen,
((u8 *)pbuf)[box_addr] &= ~box_mask;
((u8 *)pbuf)[box_addr] |= pval;
}
- return 0;
}
-EXPORT_SYMBOL(pack);
/**
- * unpack - Unpack u64 number from packed buffer.
+ * pack - Pack u64 number into bitfield of buffer.
*
* @pbuf: Pointer to a buffer holding the packed value.
- * @uval: Pointer to an u64 holding the unpacked value.
+ * @uval: CPU-readable unpacked value to pack.
* @startbit: The index (in logical notation, compensated for quirks) where
* the packed value starts within pbuf. Must be larger than, or
* equal to, endbit.
@@ -183,16 +137,12 @@ EXPORT_SYMBOL(pack);
* QUIRK_MSB_ON_THE_RIGHT.
*
* Return: 0 on success, EINVAL or ERANGE if called incorrectly. Assuming
- * correct usage, return code may be discarded. The @uval will be
- * modified on success.
+ * correct usage, return code may be discarded. The @pbuf memory will
+ * be modified on success.
*/
-int unpack(const void *pbuf, u64 *uval, size_t startbit, size_t endbit,
- size_t pbuflen, u8 quirks)
+int pack(void *pbuf, u64 uval, size_t startbit, size_t endbit, size_t pbuflen,
+ u8 quirks)
{
- /* Logical byte indices corresponding to the
- * start and end of the field.
- */
- int plogical_first_u8, plogical_last_u8, box;
/* width of the field to access in the pbuf */
u64 value_width;
@@ -207,6 +157,33 @@ int unpack(const void *pbuf, u64 *uval, size_t startbit, size_t endbit,
if (unlikely(value_width > 64))
return -ERANGE;
+ /* Check if "uval" fits in "value_width" bits.
+ * If value_width is 64, the check will fail, but any
+ * 64-bit uval will surely fit.
+ */
+ if (value_width < 64 && uval >= (1ull << value_width))
+ /* Cannot store "uval" inside "value_width" bits.
+ * Truncating "uval" is most certainly not desirable,
+ * so simply erroring out is appropriate.
+ */
+ return -ERANGE;
+
+ __pack(pbuf, uval, startbit, endbit, pbuflen, quirks);
+
+ return 0;
+}
+EXPORT_SYMBOL(pack);
+
+static void __unpack(const void *pbuf, u64 *uval, size_t startbit,
+ size_t endbit, size_t pbuflen, u8 quirks)
+{
+ /* Logical byte indices corresponding to the
+ * start and end of the field.
+ */
+ int plogical_first_u8 = startbit / BITS_PER_BYTE;
+ int plogical_last_u8 = endbit / BITS_PER_BYTE;
+ int box;
+
/* Initialize parameter */
*uval = 0;
@@ -214,9 +191,6 @@ 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 / 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 */
size_t box_start_bit, box_end_bit, box_addr;
@@ -271,6 +245,46 @@ int unpack(const void *pbuf, u64 *uval, size_t startbit, size_t endbit,
*uval &= ~proj_mask;
*uval |= pval;
}
+}
+
+/**
+ * unpack - Unpack u64 number from packed buffer.
+ *
+ * @pbuf: Pointer to a buffer holding the packed value.
+ * @uval: Pointer to an u64 holding the unpacked value.
+ * @startbit: The index (in logical notation, compensated for quirks) where
+ * the packed value starts within pbuf. Must be larger than, or
+ * equal to, endbit.
+ * @endbit: The index (in logical notation, compensated for quirks) where
+ * the packed value ends within pbuf. Must be smaller than, or equal
+ * to, startbit.
+ * @pbuflen: The length in bytes of the packed buffer pointed to by @pbuf.
+ * @quirks: A bit mask of QUIRK_LITTLE_ENDIAN, QUIRK_LSW32_IS_FIRST and
+ * QUIRK_MSB_ON_THE_RIGHT.
+ *
+ * Return: 0 on success, EINVAL or ERANGE if called incorrectly. Assuming
+ * correct usage, return code may be discarded. The @uval will be
+ * modified on success.
+ */
+int unpack(const void *pbuf, u64 *uval, size_t startbit, size_t endbit,
+ size_t pbuflen, u8 quirks)
+{
+ /* width of the field to access in the pbuf */
+ u64 value_width;
+
+ /* startbit is expected to be larger than endbit, and both are
+ * expected to be within the logically addressable range of the buffer.
+ */
+ if (startbit < endbit || startbit >= BITS_PER_BYTE * pbuflen)
+ /* Invalid function call */
+ return -EINVAL;
+
+ value_width = startbit - endbit + 1;
+ if (value_width > 64)
+ return -ERANGE;
+
+ __unpack(pbuf, uval, startbit, endbit, pbuflen, quirks);
+
return 0;
}
EXPORT_SYMBOL(unpack);