Introduce range.h

Extract range functions from pci.h. These will be used by later patches
by non-PCI devices. Adjust current users.

Signed-off-by: Blue Swirl <blauwirbel@gmail.com>

1 files changed, 29 insertions, 0 deletions

diff --git a/range.h b/range.h
new file mode 100644
index 0000000000..350237212b
--- /dev/null
+++ b/range.h
@@ -0,0 +1,29 @@
+#ifndef QEMU_RANGE_H
+#define QEMU_RANGE_H
+
+/* Get last byte of a range from offset + length.
+ * Undefined for ranges that wrap around 0. */
+static inline uint64_t range_get_last(uint64_t offset, uint64_t len)
+{
+    return offset + len - 1;
+}
+
+/* Check whether a given range covers a given byte. */
+static inline int range_covers_byte(uint64_t offset, uint64_t len,
+                                    uint64_t byte)
+{
+    return offset <= byte && byte <= range_get_last(offset, len);
+}
+
+/* Check whether 2 given ranges overlap.
+ * Undefined if ranges that wrap around 0. */
+static inline int ranges_overlap(uint64_t first1, uint64_t len1,
+                                 uint64_t first2, uint64_t len2)
+{
+    uint64_t last1 = range_get_last(first1, len1);
+    uint64_t last2 = range_get_last(first2, len2);
+
+    return !(last2 < first1 || last1 < first2);
+}
+
+#endif