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authorJoonas Lahtinen <joonas.lahtinen@linux.intel.com>2021-01-15 08:49:57 +0200
committerJoonas Lahtinen <joonas.lahtinen@linux.intel.com>2021-01-15 08:49:57 +0200
commitd263dfa7d2697a43f3299b9731cd568ee49cdd2c (patch)
treef5d993c7000ac41ee926acf0b357ec572ef7908f /tools/lib/string.c
parentdrm/i915/gt: Prune inlines (diff)
parentMerge tag 'drm-intel-gt-next-2021-01-14' of git://anongit.freedesktop.org/drm/drm-intel into drm-next (diff)
downloadwireguard-linux-d263dfa7d2697a43f3299b9731cd568ee49cdd2c.tar.xz
wireguard-linux-d263dfa7d2697a43f3299b9731cd568ee49cdd2c.zip
Merge drm/drm-next into drm-intel-gt-next
Backmerging to get a common base for merging topic branches between drm-intel-next and drm-intel-gt-next. Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Diffstat (limited to 'tools/lib/string.c')
-rw-r--r--tools/lib/string.c58
1 files changed, 58 insertions, 0 deletions
diff --git a/tools/lib/string.c b/tools/lib/string.c
index f645343815de..8b6892f959ab 100644
--- a/tools/lib/string.c
+++ b/tools/lib/string.c
@@ -168,3 +168,61 @@ char *strreplace(char *s, char old, char new)
*s = new;
return s;
}
+
+static void *check_bytes8(const u8 *start, u8 value, unsigned int bytes)
+{
+ while (bytes) {
+ if (*start != value)
+ return (void *)start;
+ start++;
+ bytes--;
+ }
+ return NULL;
+}
+
+/**
+ * memchr_inv - Find an unmatching character in an area of memory.
+ * @start: The memory area
+ * @c: Find a character other than c
+ * @bytes: The size of the area.
+ *
+ * returns the address of the first character other than @c, or %NULL
+ * if the whole buffer contains just @c.
+ */
+void *memchr_inv(const void *start, int c, size_t bytes)
+{
+ u8 value = c;
+ u64 value64;
+ unsigned int words, prefix;
+
+ if (bytes <= 16)
+ return check_bytes8(start, value, bytes);
+
+ value64 = value;
+ value64 |= value64 << 8;
+ value64 |= value64 << 16;
+ value64 |= value64 << 32;
+
+ prefix = (unsigned long)start % 8;
+ if (prefix) {
+ u8 *r;
+
+ prefix = 8 - prefix;
+ r = check_bytes8(start, value, prefix);
+ if (r)
+ return r;
+ start += prefix;
+ bytes -= prefix;
+ }
+
+ words = bytes / 8;
+
+ while (words) {
+ if (*(u64 *)start != value64)
+ return check_bytes8(start, value, 8);
+ start += 8;
+ words--;
+ }
+
+ return check_bytes8(start, value, bytes % 8);
+}