[Skiboot] [PATCH 01/32] bitmap: Add basic bitmap ops

[Benjamin Herrenschmidt]

Signed-off-by: Benjamin Herrenschmidt <benh at kernel.crashing.org>
---
 core/Makefile.inc |  2 +-
 core/bitmap.c     | 41 +++++++++++++++++++++++++++++++++
 include/bitmap.h  | 69 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 111 insertions(+), 1 deletion(-)
 create mode 100644 core/bitmap.c
 create mode 100644 include/bitmap.h

diff --git a/core/Makefile.inc b/core/Makefile.inc
index 9223af1..98bcb11 100644
--- a/core/Makefile.inc
+++ b/core/Makefile.inc
@@ -8,7 +8,7 @@ CORE_OBJS += pci-opal.o fast-reboot.o device.o exceptions.o trace.o affinity.o
 CORE_OBJS += vpd.o hostservices.o platform.o nvram.o nvram-format.o hmi.o
 CORE_OBJS += console-log.o ipmi.o time-utils.o pel.o pool.o errorlog.o
 CORE_OBJS += timer.o i2c.o rtc.o flash.o sensor.o ipmi-opal.o
-CORE_OBJS += flash-subpartition.o
+CORE_OBJS += flash-subpartition.o bitmap.o
 
 ifeq ($(SKIBOOT_GCOV),1)
 CORE_OBJS += gcov-profiling.o
diff --git a/core/bitmap.c b/core/bitmap.c
new file mode 100644
index 0000000..f07b6ab
--- /dev/null
+++ b/core/bitmap.c
@@ -0,0 +1,41 @@
+#include "bitmap.h"
+
+static int __bitmap_find_bit(bitmap_t map, unsigned int start, unsigned int count,
+			     bool value)
+{
+	unsigned int el, first_bit;
+	unsigned int end = start + count;
+	bitmap_elem_t e, ev;
+	int b;
+
+	ev = value ? -1ul : 0;
+	el = BITMAP_ELEM(start);
+	first_bit = BITMAP_BIT(start);
+
+	while (start < end) {
+		e = map[el] ^ ev;
+		e |= ((1ul << first_bit) - 1);
+		if (~e)
+			break;
+		start = (start + BITMAP_ELSZ) & ~(BITMAP_ELSZ - 1);
+		first_bit = 0;
+		el++;
+	}
+	for (b = first_bit; b < BITMAP_ELSZ && start < end; b++,start++) {
+		if ((e & (1ull << b)) == 0)
+			return start;
+	}
+
+	return -1;
+}
+
+int bitmap_find_zero_bit(bitmap_t map, unsigned int start, unsigned int count)
+{
+	return __bitmap_find_bit(map, start, count, false);
+}
+
+int bitmap_find_one_bit(bitmap_t map, unsigned int start, unsigned int count)
+{
+	return __bitmap_find_bit(map, start, count, true);
+}
+
diff --git a/include/bitmap.h b/include/bitmap.h
new file mode 100644
index 0000000..12913ea
--- /dev/null
+++ b/include/bitmap.h
@@ -0,0 +1,69 @@
+/* Copyright 2016 IBM Corp.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * 	http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+ * implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef __BITMAP_H
+#define __BITMAP_H
+
+#include <stdint.h>
+#include <stdbool.h>
+
+typedef unsigned long bitmap_elem_t;
+typedef bitmap_elem_t bitmap_t[];
+
+#define BITMAP_ELSZ	(sizeof(bitmap_elem_t) << 3)
+
+/* Number of elements for _n bits (rounded up) */
+#define BITMAP_ELEMS(_n)	(((_n) + (BITMAP_ELSZ - 1)) / BITMAP_ELSZ)
+/* Number of bytes for _n bits (rounded up) */
+#define BITMAP_BYTES(_n)	(BITMAP_ELEMS(_n) * sizeof(bitmap_elem_t))
+/* Bit number within an elemnt for bit _n */
+#define BITMAP_BIT(_n)		((_n) & (BITMAP_ELSZ - 1))
+/* Corresponding mask */
+#define BITMAP_MASK(_n)		(1ul << BITMAP_BIT(_n))
+/* Element number for bit _n */
+#define BITMAP_ELEM(_n)		((_n) / BITMAP_ELSZ)
+
+static inline void bitmap_set_bit(bitmap_t map, unsigned int bit)
+{
+	map[BITMAP_ELEM(bit)] |= BITMAP_MASK(bit);
+}
+
+static inline void bitmap_clr_bit(bitmap_t map, unsigned int bit)
+{
+	map[BITMAP_ELEM(bit)] &= ~BITMAP_MASK(bit);
+}
+
+static inline bool bitmap_tst_bit(bitmap_t map, unsigned int bit)
+{
+	return map[BITMAP_ELEM(bit)] & BITMAP_MASK(bit);
+}
+
+extern int bitmap_find_zero_bit(bitmap_t map, unsigned int start,
+				unsigned int count);
+extern int bitmap_find_one_bit(bitmap_t map, unsigned int start,
+				unsigned int count);
+
+#define bitmap_for_each_zero(map, size, bit)                   \
+	for (bit = bitmap_find_zero_bit(map, 0, size);         \
+	     bit >= 0;					       \
+	     bit = bitmap_find_zero_bit(map, bit + 1, size))
+
+#define bitmap_for_each_one(map, size, bit)                    \
+	for (bit = bitmap_find_one_bit(map, 0, size);          \
+	     bit >= 0;					       \
+	     bit = bitmap_find_one_bit(map, bit + 1, size))
+
+#endif /* __BITMAP_H */
-- 
2.7.4