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authorAndy Shevchenko <andriy.shevchenko@linux.intel.com>2019-12-04 16:53:26 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2019-12-04 19:44:14 -0800
commit30544ed5de431fe25d3793e4dd5a058d877c4d77 (patch)
tree4e61a782d8482dc987228ecddd854441f9bb6f68 /lib
parent780ff33b8bfac4f44fcc399a870d50ff2e74b33d (diff)
lib/bitmap: introduce bitmap_replace() helper
In some drivers we want to have a single operation over bitmap which is an equivalent to: *dst = (*old & ~(*mask)) | (*new & *mask) Introduce bitmap_replace() helper for this. Link: http://lkml.kernel.org/r/20191022172922.61232-8-andriy.shevchenko@linux.intel.com Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Linus Walleij <linus.walleij@linaro.org> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Marek Vasut <marek.vasut+renesas@gmail.com> Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com> Cc: William Breathitt Gray <vilhelm.gray@gmail.com> Cc: Yury Norov <yury.norov@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib')
-rw-r--r--lib/bitmap.c12
-rw-r--r--lib/test_bitmap.c38
2 files changed, 50 insertions, 0 deletions
diff --git a/lib/bitmap.c b/lib/bitmap.c
index f9e834841e94..4250519d7d1c 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -222,6 +222,18 @@ int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
}
EXPORT_SYMBOL(__bitmap_andnot);
+void __bitmap_replace(unsigned long *dst,
+ const unsigned long *old, const unsigned long *new,
+ const unsigned long *mask, unsigned int nbits)
+{
+ unsigned int k;
+ unsigned int nr = BITS_TO_LONGS(nbits);
+
+ for (k = 0; k < nr; k++)
+ dst[k] = (old[k] & ~mask[k]) | (new[k] & mask[k]);
+}
+EXPORT_SYMBOL(__bitmap_replace);
+
int __bitmap_intersects(const unsigned long *bitmap1,
const unsigned long *bitmap2, unsigned int bits)
{
diff --git a/lib/test_bitmap.c b/lib/test_bitmap.c
index 4544847cf81e..e14a15ac250b 100644
--- a/lib/test_bitmap.c
+++ b/lib/test_bitmap.c
@@ -42,6 +42,19 @@ static const unsigned long exp2[] __initconst = {
BITMAP_FROM_U64(0xffffffff77777777ULL),
};
+/* Fibonacci sequence */
+static const unsigned long exp2_to_exp3_mask[] __initconst = {
+ BITMAP_FROM_U64(0x008000020020212eULL),
+};
+/* exp3_0_1 = (exp2[0] & ~exp2_to_exp3_mask) | (exp2[1] & exp2_to_exp3_mask) */
+static const unsigned long exp3_0_1[] __initconst = {
+ BITMAP_FROM_U64(0x33b3333311313137ULL),
+};
+/* exp3_1_0 = (exp2[1] & ~exp2_to_exp3_mask) | (exp2[0] & exp2_to_exp3_mask) */
+static const unsigned long exp3_1_0[] __initconst = {
+ BITMAP_FROM_U64(0xff7fffff77575751ULL),
+};
+
static bool __init
__check_eq_uint(const char *srcfile, unsigned int line,
const unsigned int exp_uint, unsigned int x)
@@ -257,6 +270,30 @@ static void __init test_copy(void)
expect_eq_pbl("0-108,128-1023", bmap2, 1024);
}
+#define EXP2_IN_BITS (sizeof(exp2) * 8)
+
+static void __init test_replace(void)
+{
+ unsigned int nbits = 64;
+ DECLARE_BITMAP(bmap, 1024);
+
+ bitmap_zero(bmap, 1024);
+ bitmap_replace(bmap, &exp2[0], &exp2[1], exp2_to_exp3_mask, nbits);
+ expect_eq_bitmap(bmap, exp3_0_1, nbits);
+
+ bitmap_zero(bmap, 1024);
+ bitmap_replace(bmap, &exp2[1], &exp2[0], exp2_to_exp3_mask, nbits);
+ expect_eq_bitmap(bmap, exp3_1_0, nbits);
+
+ bitmap_fill(bmap, 1024);
+ bitmap_replace(bmap, &exp2[0], &exp2[1], exp2_to_exp3_mask, nbits);
+ expect_eq_bitmap(bmap, exp3_0_1, nbits);
+
+ bitmap_fill(bmap, 1024);
+ bitmap_replace(bmap, &exp2[1], &exp2[0], exp2_to_exp3_mask, nbits);
+ expect_eq_bitmap(bmap, exp3_1_0, nbits);
+}
+
#define PARSE_TIME 0x1
struct test_bitmap_parselist{
@@ -476,6 +513,7 @@ static void __init selftest(void)
test_zero_clear();
test_fill_set();
test_copy();
+ test_replace();
test_bitmap_arr32();
test_bitmap_parselist();
test_bitmap_parselist_user();