xnu-4903.221.2.tar.gz

[apple/xnu.git] / osfmk / kern / bits.h

diff --git a/osfmk/kern/bits.h b/osfmk/kern/bits.h
index 5c977497d662ddfbea1f9b7699b83b356fe5e41b..13ce948d2ad4313f9216d0df457c489101ce96fa 100644 (file)
--- a/osfmk/kern/bits.h
+++ b/osfmk/kern/bits.h
@@ -39,7 +39,7 @@ typedef unsigned int                  uint;
 
 #define BIT(b)                         (1ULL << (b))
 
-#define mask(width)                    (BIT(width) - 1)
+#define mask(width)                    (width >= 64 ? -1 : (BIT(width) - 1))
 #define extract(x, shift, width)       ((((uint64_t)(x)) >> (shift)) & mask(width))
 #define bits(x, hi, lo)                        extract((x), (lo), (hi) - (lo) + 1)
 
@@ -47,6 +47,31 @@ typedef unsigned int                 uint;
 #define bit_clear(x, b)                        ((x) &= ~BIT(b))
 #define bit_test(x, b)                 ((bool)((x) & BIT(b)))
 
+inline static uint64_t
+bit_ror64(uint64_t bitmap, uint n)
+{
+#if defined(__arm64__)
+       uint64_t result;
+       uint64_t _n = (uint64_t)n;
+       asm volatile("ror %0, %1, %2" : "=r" (result) : "r" (bitmap), "r" (_n));
+       return result;
+#else
+       n = n & 63;
+       return ((bitmap >> n) | (bitmap << (64 - n)));
+#endif
+}
+
+inline static uint64_t
+bit_rol64(uint64_t bitmap, uint n)
+{
+#if defined(__arm64__)
+       return bit_ror64(bitmap, 64U - n);
+#else
+       n = n & 63;
+       return ((bitmap << n) | (bitmap >> (64 - n)));
+#endif
+}
+
 /* Non-atomically clear the bit and returns whether the bit value was changed */
 inline static bool
 bit_clear_if_set(uint64_t bitmap, int bit)