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authorYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 12:17:53 -0700
committerYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 15:44:42 -0700
commit9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch)
tree1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/arch/s390/lib/find.c
parent98260f3884f4a202f9ca5eabed40b1354c489b29 (diff)
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/arch/s390/lib/find.c')
-rw-r--r--kernel/arch/s390/lib/find.c77
1 files changed, 77 insertions, 0 deletions
diff --git a/kernel/arch/s390/lib/find.c b/kernel/arch/s390/lib/find.c
new file mode 100644
index 000000000..922003c1b
--- /dev/null
+++ b/kernel/arch/s390/lib/find.c
@@ -0,0 +1,77 @@
+/*
+ * MSB0 numbered special bitops handling.
+ *
+ * On s390x the bits are numbered:
+ * |0..............63|64............127|128...........191|192...........255|
+ * and on s390:
+ * |0.....31|32....63|64....95|96...127|128..159|160..191|192..223|224..255|
+ *
+ * The reason for this bit numbering is the fact that the hardware sets bits
+ * in a bitmap starting at bit 0 (MSB) and we don't want to scan the bitmap
+ * from the 'wrong end'.
+ */
+
+#include <linux/compiler.h>
+#include <linux/bitops.h>
+#include <linux/export.h>
+
+unsigned long find_first_bit_inv(const unsigned long *addr, unsigned long size)
+{
+ const unsigned long *p = addr;
+ unsigned long result = 0;
+ unsigned long tmp;
+
+ while (size & ~(BITS_PER_LONG - 1)) {
+ if ((tmp = *(p++)))
+ goto found;
+ result += BITS_PER_LONG;
+ size -= BITS_PER_LONG;
+ }
+ if (!size)
+ return result;
+ tmp = (*p) & (~0UL << (BITS_PER_LONG - size));
+ if (!tmp) /* Are any bits set? */
+ return result + size; /* Nope. */
+found:
+ return result + (__fls(tmp) ^ (BITS_PER_LONG - 1));
+}
+EXPORT_SYMBOL(find_first_bit_inv);
+
+unsigned long find_next_bit_inv(const unsigned long *addr, unsigned long size,
+ unsigned long offset)
+{
+ const unsigned long *p = addr + (offset / BITS_PER_LONG);
+ unsigned long result = offset & ~(BITS_PER_LONG - 1);
+ unsigned long tmp;
+
+ if (offset >= size)
+ return size;
+ size -= result;
+ offset %= BITS_PER_LONG;
+ if (offset) {
+ tmp = *(p++);
+ tmp &= (~0UL >> offset);
+ if (size < BITS_PER_LONG)
+ goto found_first;
+ if (tmp)
+ goto found_middle;
+ size -= BITS_PER_LONG;
+ result += BITS_PER_LONG;
+ }
+ while (size & ~(BITS_PER_LONG-1)) {
+ if ((tmp = *(p++)))
+ goto found_middle;
+ result += BITS_PER_LONG;
+ size -= BITS_PER_LONG;
+ }
+ if (!size)
+ return result;
+ tmp = *p;
+found_first:
+ tmp &= (~0UL << (BITS_PER_LONG - size));
+ if (!tmp) /* Are any bits set? */
+ return result + size; /* Nope. */
+found_middle:
+ return result + (__fls(tmp) ^ (BITS_PER_LONG - 1));
+}
+EXPORT_SYMBOL(find_next_bit_inv);