Merge tag 'for-linus-6.0-rc1b-tag' of git://git.kernel.org/pub/scm/linux/kernel/git...

[linux-2.6-microblaze.git] / lib / test_bitmap.c

diff --git a/lib/test_bitmap.c b/lib/test_bitmap.c
index d5923a6..98754ff 100644 (file)
--- a/lib/test_bitmap.c
+++ b/lib/test_bitmap.c
@@ -604,6 +604,12 @@ static void __init test_bitmap_arr64(void)
                        pr_err("bitmap_copy_arr64(nbits == %d:"
                                " tail is not safely cleared: %d\n", nbits, next_bit);
 
+               if ((nbits % 64) &&
+                   (arr[(nbits - 1) / 64] & ~GENMASK_ULL((nbits - 1) % 64, 0)))
+                       pr_err("bitmap_to_arr64(nbits == %d): tail is not safely cleared: 0x%016llx (must be 0x%016llx)\n",
+                              nbits, arr[(nbits - 1) / 64],
+                              GENMASK_ULL((nbits - 1) % 64, 0));
+
                if (nbits < EXP1_IN_BITS - 64)
                        expect_eq_uint(arr[DIV_ROUND_UP(nbits, 64)], 0xa5a5a5a5);
        }
@@ -869,6 +875,67 @@ static void __init test_bitmap_print_buf(void)
        }
 }
 
+static void __init test_bitmap_const_eval(void)
+{
+       DECLARE_BITMAP(bitmap, BITS_PER_LONG);
+       unsigned long initvar = BIT(2);
+       unsigned long bitopvar = 0;
+       unsigned long var = 0;
+       int res;
+
+       /*
+        * Compilers must be able to optimize all of those to compile-time
+        * constants on any supported optimization level (-O2, -Os) and any
+        * architecture. Otherwise, trigger a build bug.
+        * The whole function gets optimized out then, there's nothing to do
+        * in runtime.
+        */
+
+       /*
+        * Equals to `unsigned long bitmap[1] = { GENMASK(6, 5), }`.
+        * Clang on s390 optimizes bitops at compile-time as intended, but at
+        * the same time stops treating @bitmap and @bitopvar as compile-time
+        * constants after regular test_bit() is executed, thus triggering the
+        * build bugs below. So, call const_test_bit() there directly until
+        * the compiler is fixed.
+        */
+       bitmap_clear(bitmap, 0, BITS_PER_LONG);
+#if defined(__s390__) && defined(__clang__)
+       if (!const_test_bit(7, bitmap))
+#else
+       if (!test_bit(7, bitmap))
+#endif
+               bitmap_set(bitmap, 5, 2);
+
+       /* Equals to `unsigned long bitopvar = BIT(20)` */
+       __change_bit(31, &bitopvar);
+       bitmap_shift_right(&bitopvar, &bitopvar, 11, BITS_PER_LONG);
+
+       /* Equals to `unsigned long var = BIT(25)` */
+       var |= BIT(25);
+       if (var & BIT(0))
+               var ^= GENMASK(9, 6);
+
+       /* __const_hweight<32|64>(GENMASK(6, 5)) == 2 */
+       res = bitmap_weight(bitmap, 20);
+       BUILD_BUG_ON(!__builtin_constant_p(res));
+       BUILD_BUG_ON(res != 2);
+
+       /* !(BIT(31) & BIT(18)) == 1 */
+       res = !test_bit(18, &bitopvar);
+       BUILD_BUG_ON(!__builtin_constant_p(res));
+       BUILD_BUG_ON(!res);
+
+       /* BIT(2) & GENMASK(14, 8) == 0 */
+       res = initvar & GENMASK(14, 8);
+       BUILD_BUG_ON(!__builtin_constant_p(res));
+       BUILD_BUG_ON(res);
+
+       /* ~BIT(25) */
+       BUILD_BUG_ON(!__builtin_constant_p(~var));
+       BUILD_BUG_ON(~var != ~BIT(25));
+}
+
 static void __init selftest(void)
 {
        test_zero_clear();
@@ -884,6 +951,7 @@ static void __init selftest(void)
        test_for_each_set_clump8();
        test_bitmap_cut();
        test_bitmap_print_buf();
+       test_bitmap_const_eval();
 }
 
 KSTM_MODULE_LOADERS(test_bitmap);