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authorLinus Torvalds <torvalds@linux-foundation.org>2009-08-21 12:26:15 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2009-08-21 12:26:15 -0400
commitf4b0373b26567cafd421d91101852ed7a34e9e94 (patch)
tree35607b1c1d28429bb275ca3472cd0065fbde2f14 /lib/bitmap.c
parent83d349f35e1ae72268c5104dbf9ab2ae635425d4 (diff)
Make bitmask 'and' operators return a result code
When 'and'ing two bitmasks (where 'andnot' is a variation on it), some cases want to know whether the result is the empty set or not. In particular, the TLB IPI sending code wants to do cpumask operations and determine if there are any CPU's left in the final set. So this just makes the bitmask (and cpumask) functions return a boolean for whether the result has any bits set. Cc: stable@kernel.org (2.6.30, needed by TLB shootdown fix) Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib/bitmap.c')
-rw-r--r--lib/bitmap.c12
1 files changed, 8 insertions, 4 deletions
diff --git a/lib/bitmap.c b/lib/bitmap.c
index 35a1f7ff4149..702565821c99 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -179,14 +179,16 @@ void __bitmap_shift_left(unsigned long *dst,
179} 179}
180EXPORT_SYMBOL(__bitmap_shift_left); 180EXPORT_SYMBOL(__bitmap_shift_left);
181 181
182void __bitmap_and(unsigned long *dst, const unsigned long *bitmap1, 182int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
183 const unsigned long *bitmap2, int bits) 183 const unsigned long *bitmap2, int bits)
184{ 184{
185 int k; 185 int k;
186 int nr = BITS_TO_LONGS(bits); 186 int nr = BITS_TO_LONGS(bits);
187 unsigned long result = 0;
187 188
188 for (k = 0; k < nr; k++) 189 for (k = 0; k < nr; k++)
189 dst[k] = bitmap1[k] & bitmap2[k]; 190 result |= (dst[k] = bitmap1[k] & bitmap2[k]);
191 return result != 0;
190} 192}
191EXPORT_SYMBOL(__bitmap_and); 193EXPORT_SYMBOL(__bitmap_and);
192 194
@@ -212,14 +214,16 @@ void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
212} 214}
213EXPORT_SYMBOL(__bitmap_xor); 215EXPORT_SYMBOL(__bitmap_xor);
214 216
215void __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1, 217int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
216 const unsigned long *bitmap2, int bits) 218 const unsigned long *bitmap2, int bits)
217{ 219{
218 int k; 220 int k;
219 int nr = BITS_TO_LONGS(bits); 221 int nr = BITS_TO_LONGS(bits);
222 unsigned long result = 0;
220 223
221 for (k = 0; k < nr; k++) 224 for (k = 0; k < nr; k++)
222 dst[k] = bitmap1[k] & ~bitmap2[k]; 225 result |= (dst[k] = bitmap1[k] & ~bitmap2[k]);
226 return result != 0;
223} 227}
224EXPORT_SYMBOL(__bitmap_andnot); 228EXPORT_SYMBOL(__bitmap_andnot);
225 229