1 files changed, 132 insertions, 0 deletions

diff --git a/arch/sparc/lib/bitext.c b/arch/sparc/lib/bitext.c
new file mode 100644
index 000000000000..94b05e8c906c
--- /dev/null
+++ b/arch/sparc/lib/bitext.c
@@ -0,0 +1,132 @@
+/*
+ * bitext.c: kernel little helper (of bit shuffling variety).
+ *
+ * Copyright (C) 2002 Pete Zaitcev <zaitcev@yahoo.com>
+ *
+ * The algorithm to search a zero bit string is geared towards its application.
+ * We expect a couple of fixed sizes of requests, so a rotating counter, reset
+ * by align size, should provide fast enough search while maintaining low
+ * fragmentation.
+ */
+
+#include <linux/smp_lock.h>
+#include <linux/bitops.h>
+
+#include <asm/bitext.h>
+
+/**
+ * bit_map_string_get - find and set a bit string in bit map.
+ * @t: the bit map.
+ * @len: requested string length
+ * @align: requested alignment
+ *
+ * Returns offset in the map or -1 if out of space.
+ *
+ * Not safe to call from an interrupt (uses spin_lock).
+ */
+int bit_map_string_get(struct bit_map *t, int len, int align)
+{
+        int offset, count;      /* siamese twins */
+        int off_new;
+        int align1;
+        int i, color;
+
+        if (t->num_colors) {
+                /* align is overloaded to be the page color */
+                color = align;
+                align = t->num_colors;
+        } else {
+                color = 0;
+                if (align == 0)
+                        align = 1;
+        }
+        align1 = align - 1;
+        if ((align & align1) != 0)
+                BUG();
+        if (align < 0 || align >= t->size)
+                BUG();
+        if (len <= 0 || len > t->size)
+                BUG();
+        color &= align1;
+
+        spin_lock(&t->lock);
+        if (len < t->last_size)
+                offset = t->first_free;
+        else
+                offset = t->last_off & ~align1;
+        count = 0;
+        for (;;) {
+                off_new = find_next_zero_bit(t->map, t->size, offset);
+                off_new = ((off_new + align1) & ~align1) + color;
+                count += off_new - offset;
+                offset = off_new;
+                if (offset >= t->size)
+                        offset = 0;
+                if (count + len > t->size) {
+                        spin_unlock(&t->lock);
+/* P3 */ printk(KERN_ERR
+  "bitmap out: size %d used %d off %d len %d align %d count %d\n",
+  t->size, t->used, offset, len, align, count);
+                        return -1;
+                }
+
+                if (offset + len > t->size) {
+                        count += t->size - offset;
+                        offset = 0;
+                        continue;
+                }
+
+                i = 0;
+                while (test_bit(offset + i, t->map) == 0) {
+                        i++;
+                        if (i == len) {
+                                for (i = 0; i < len; i++)
+                                        __set_bit(offset + i, t->map);
+                                if (offset == t->first_free)
+                                        t->first_free = find_next_zero_bit
+                                                        (t->map, t->size,
+                                                         t->first_free + len);
+                                if ((t->last_off = offset + len) >= t->size)
+                                        t->last_off = 0;
+                                t->used += len;
+                                t->last_size = len;
+                                spin_unlock(&t->lock);
+                                return offset;
+                        }
+                }
+                count += i + 1;
+                if ((offset += i + 1) >= t->size)
+                        offset = 0;
+        }
+}
+
+void bit_map_clear(struct bit_map *t, int offset, int len)
+{
+        int i;
+
+        if (t->used < len)
+                BUG();          /* Much too late to do any good, but alas... */
+        spin_lock(&t->lock);
+        for (i = 0; i < len; i++) {
+                if (test_bit(offset + i, t->map) == 0)
+                        BUG();
+                __clear_bit(offset + i, t->map);
+        }
+        if (offset < t->first_free)
+                t->first_free = offset;
+        t->used -= len;
+        spin_unlock(&t->lock);
+}
+
+void bit_map_init(struct bit_map *t, unsigned long *map, int size)
+{
+
+        if ((size & 07) != 0)
+                BUG();
+        memset(map, 0, size>>3);
+
+        memset(t, 0, sizeof *t);
+        spin_lock_init(&t->lock);
+        t->map = map;
+        t->size = size;
+}