platform/swap: move swap inline functions & macros into an own header

These inline functions and macros are only used in
platform/endian_(big|little).c and do not need to be compiled into every
object which includes `platform.h`.

Change-Id: Ib2326e6a4eb5e000a0eace857d040372e2e9e561
Signed-off-by: Thomas Heijligen <thomas.heijligen@secunet.com>
Reviewed-on: https://review.coreboot.org/c/flashrom/+/63825
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>

1 files changed, 80 insertions, 0 deletions

diff --git a/include/platform/swap.h b/include/platform/swap.h
new file mode 100644
index 00000000..12f31065
--- /dev/null
+++ b/include/platform/swap.h
@@ -0,0 +1,80 @@
+/*
+ * This file is part of the flashrom project.
+ *
+ * Copyright (C) 2009 Carl-Daniel Hailfinger
+ * Copyright (C) 2022 secunet Security Networks AG
+ * (written by Thomas Heijligen <thomas.heijligen@secunet.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+/*
+ * inline functions and macros shared by endian conversion functions
+ */
+
+#ifndef ___SWAP_H___
+#define ___SWAP_H___ 1
+
+#include <stdint.h>
+
+/* swap bytes */
+/* OpenBSD has conflicting definitions for swapX, _swap_X and __swapX */
+static inline uint8_t ___swap8(const uint8_t value)
+{
+	return  (value & (uint8_t)0xffU);
+}
+
+static inline uint16_t ___swap16(const uint16_t value)
+{
+	return  ((value & (uint16_t)0x00ffU) << 8) |
+		((value & (uint16_t)0xff00U) >> 8);
+}
+
+static inline uint32_t ___swap32(const uint32_t value)
+{
+	return  ((value & (uint32_t)0x000000ffUL) << 24) |
+		((value & (uint32_t)0x0000ff00UL) <<  8) |
+		((value & (uint32_t)0x00ff0000UL) >>  8) |
+		((value & (uint32_t)0xff000000UL) >> 24);
+}
+
+static inline uint64_t ___swap64(const uint64_t value)
+{
+	return  ((value & (uint64_t)0x00000000000000ffULL) << 56) |
+		((value & (uint64_t)0x000000000000ff00ULL) << 40) |
+		((value & (uint64_t)0x0000000000ff0000ULL) << 24) |
+		((value & (uint64_t)0x00000000ff000000ULL) <<  8) |
+		((value & (uint64_t)0x000000ff00000000ULL) >>  8) |
+		((value & (uint64_t)0x0000ff0000000000ULL) >> 24) |
+		((value & (uint64_t)0x00ff000000000000ULL) >> 40) |
+		((value & (uint64_t)0xff00000000000000ULL) >> 56);
+}
+
+/*
+ * macro to return the same value as passed.
+ *
+ * `___return_same(cpu_to_le, 8)`
+ *	expands to
+ * `uint8_t cpu_to_le8 (const uint8_t value) { return value; }`
+ */
+#define ___return_same(name, bits) \
+	uint##bits##_t name##bits (const uint##bits##_t value) { return value; }
+
+/*
+ * macro to return the swapped value as passed.
+ *
+ * `___return_swapped(cpu_to_be, 8)`
+ *	expands to
+ * `uint8_t cpu_to_be8 (const uint8_t value) { return ___swap8 (value); }`
+ */
+#define ___return_swapped(name, bits) \
+	uint##bits##_t name##bits (const uint##bits##_t value) { return ___swap##bits (value); }
+
+#endif /* !___SWAP_H___ */