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>
diff --git a/lib/test_bitmap.c b/lib/test_bitmap.c
index 4544847..e14a15a 100644
--- a/lib/test_bitmap.c
+++ b/lib/test_bitmap.c
@@ -42,6 +42,19 @@
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 @@
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 @@
test_zero_clear();
test_fill_set();
test_copy();
+ test_replace();
test_bitmap_arr32();
test_bitmap_parselist();
test_bitmap_parselist_user();