1 files changed, 39 insertions, 0 deletions
diff --git a/lib/bitops.h b/lib/bitops.h
new file mode 100644
index 0000000..029741e
--- /dev/null
+++ b/lib/bitops.h
@@ -0,0 +1,39 @@
+/*
+ *	The PCI Utilities -- Decode bits and bit fields
+ *
+ *	Copyright (c) 2023 Martin Mares <mj@ucw.cz>
+ *	Copyright (c) 2023 KNS Group LLC (YADRO)
+ *
+ *	Can be freely distributed and used under the terms of the GNU GPL v2+.
+ *
+ *	SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#ifndef _BITOPS_H
+#define _BITOPS_H
+
+#ifndef _PCI_LIB_H
+#error Import only from pci.h
+#endif
+
+/* Useful macros for decoding of bits and bit fields */
+
+#define FLAG(x, y) ((x & y) ? '+' : '-')
+
+// Generate mask
+
+#define BIT(at) ((u64)1 << (at))
+// Boundaries inclusive
+#define MASK(h, l)   ((((u64)1 << ((h) + 1)) - 1) & ~(((u64)1 << (l)) - 1))
+
+// Get/set from register
+
+#define BITS(x, at, width)      (((x) >> (at)) & ((1 << (width)) - 1))
+#define GET_REG_MASK(reg, mask) (((reg) & (mask)) / ((mask) & ~((mask) << 1)))
+#define SET_REG_MASK(reg, mask, val)                                                               \
+  (((reg) & ~(mask)) | (((val) * ((mask) & ~((mask) << 1))) & (mask)))
+
+#define TABLE(tab, x, buf)                                                                         \
+  ((x) < sizeof(tab) / sizeof((tab)[0]) ? (tab)[x] : (sprintf((buf), "??%d", (x)), (buf)))
+
+#endif