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authorYury Norov <yury.norov@gmail.com>2022-04-28 13:51:13 -0700
committerYury Norov <yury.norov@gmail.com>2022-06-03 06:52:58 -0700
commit0a97953fd2210d0ac8eb5c76f8bd08fb53b6d3d6 (patch)
tree6e885d7e9e651c08d3db29539df803d48f7ae193 /include
parente041e0ac53dd52d2d201aa87edc3adaca1085299 (diff)
lib: add bitmap_{from,to}_arr64
Manipulating 64-bit arrays with bitmap functions is potentially dangerous because on 32-bit BE machines the order of halfwords doesn't match. Another issue is that compiler may throw a warning about out-of-boundary access. This patch adds bitmap_{from,to}_arr64 functions in addition to existing bitmap_{from,to}_arr32. CC: Alexander Gordeev <agordeev@linux.ibm.com> CC: Andy Shevchenko <andriy.shevchenko@linux.intel.com> CC: Christian Borntraeger <borntraeger@linux.ibm.com> CC: Claudio Imbrenda <imbrenda@linux.ibm.com> CC: David Hildenbrand <david@redhat.com> CC: Heiko Carstens <hca@linux.ibm.com> CC: Janosch Frank <frankja@linux.ibm.com> CC: Rasmus Villemoes <linux@rasmusvillemoes.dk> CC: Sven Schnelle <svens@linux.ibm.com> CC: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Yury Norov <yury.norov@gmail.com>
Diffstat (limited to 'include')
-rw-r--r--include/linux/bitmap.h23
1 files changed, 19 insertions, 4 deletions
diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h
index afcf7b8dddd1..71147b7d721b 100644
--- a/include/linux/bitmap.h
+++ b/include/linux/bitmap.h
@@ -72,6 +72,8 @@ struct device;
* bitmap_allocate_region(bitmap, pos, order) Allocate specified bit region
* bitmap_from_arr32(dst, buf, nbits) Copy nbits from u32[] buf to dst
* bitmap_to_arr32(buf, src, nbits) Copy nbits from buf to u32[] dst
+ * bitmap_to_arr64(buf, src, nbits) Copy nbits from buf to u64[] dst
+ * bitmap_to_arr64(buf, src, nbits) Copy nbits from buf to u64[] dst
* bitmap_get_value8(map, start) Get 8bit value from map at start
* bitmap_set_value8(map, value, start) Set 8bit value to map at start
*
@@ -285,6 +287,22 @@ void bitmap_to_arr32(u32 *buf, const unsigned long *bitmap,
(const unsigned long *) (bitmap), (nbits))
#endif
+/*
+ * On 64-bit systems bitmaps are represented as u64 arrays internally. On LE32
+ * machines the order of hi and lo parts of numbers match the bitmap structure.
+ * In both cases conversion is not needed when copying data from/to arrays of
+ * u64.
+ */
+#if (BITS_PER_LONG == 32) && defined(__BIG_ENDIAN)
+void bitmap_from_arr64(unsigned long *bitmap, const u64 *buf, unsigned int nbits);
+void bitmap_to_arr64(u64 *buf, const unsigned long *bitmap, unsigned int nbits);
+#else
+#define bitmap_from_arr64(bitmap, buf, nbits) \
+ bitmap_copy_clear_tail((unsigned long *)(bitmap), (const unsigned long *)(buf), (nbits))
+#define bitmap_to_arr64(buf, bitmap, nbits) \
+ bitmap_copy_clear_tail((unsigned long *)(buf), (const unsigned long *)(bitmap), (nbits))
+#endif
+
static inline int bitmap_and(unsigned long *dst, const unsigned long *src1,
const unsigned long *src2, unsigned int nbits)
{
@@ -518,10 +536,7 @@ static inline void bitmap_next_set_region(unsigned long *bitmap,
*/
static inline void bitmap_from_u64(unsigned long *dst, u64 mask)
{
- dst[0] = mask & ULONG_MAX;
-
- if (sizeof(mask) > sizeof(unsigned long))
- dst[1] = mask >> 32;
+ bitmap_from_arr64(dst, &mask, 64);
}
/**