diff mbox series

[v6,01/15] xen: Implement common byte{order,swap}.h

Message ID 20250416115900.2491661-2-andrew.cooper3@citrix.com (mailing list archive)
State New
Headers show
Series xen: Centralise byteswap infrastructure | expand

Commit Message

Andrew Cooper April 16, 2025, 11:58 a.m. UTC 
From: Lin Liu <lin.liu@citrix.com>

The current swab??() infrastructure is unecesserily complicated, and can be
replaced entirely with compiler builtins.

All supported compilers provide __BYTE_ORDER__ and __builtin_bswap??().

Nothing in Xen cares about the values of __{BIG,LITTLE}_ENDIAN; just that one
of them is defined.  Therefore, centralise their definitions in xen/config.h

Signed-off-by: Lin Liu <lin.liu@citrix.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
---
CC: Anthony PERARD <anthony.perard@vates.tech>
CC: Michal Orzel <michal.orzel@amd.com>
CC: Jan Beulich <jbeulich@suse.com>
CC: Julien Grall <julien@xen.org>
CC: Roger Pau Monné <roger.pau@citrix.com>
CC: Stefano Stabellini <sstabellini@kernel.org>
CC: Volodymyr Babchuk <Volodymyr_Babchuk@epam.com>
CC: Bertrand Marquis <bertrand.marquis@arm.com>
CC: Shawn Anastasio <sanastasio@raptorengineering.com>
CC: Oleksii Kurochko <oleksii.kurochko@gmail.com>
CC: Daniel P. Smith <dpsmith@apertussolutions.com>
CC: Lin Liu <lin.liu@citrix.com>

v6:
 * Fix typos
 * Retain __{BIG,LITTLE}_ENDIAN_BITFIELDS and set them in common logic.
 * Extra brackets for the non-transformed case.

v5:
 * Rebase substantially
 * Drop PASTE().  It doesn't work when BITS_PER_LONG isn't a plain integer
 * Simplify in light of new toolchain baseline
---
 xen/include/xen/byteorder.h               | 44 +++++++++++++++++++++++
 xen/include/xen/byteorder/big_endian.h    |  7 ----
 xen/include/xen/byteorder/little_endian.h |  7 ----
 xen/include/xen/byteswap.h                | 15 ++++++++
 xen/include/xen/config.h                  |  8 +++++
 5 files changed, 67 insertions(+), 14 deletions(-)
 create mode 100644 xen/include/xen/byteorder.h
 create mode 100644 xen/include/xen/byteswap.h


base-commit: 7f8c2dd829358406dc9e50d5e386e4d2b20b4303
diff mbox series

Patch

diff --git a/xen/include/xen/byteorder.h b/xen/include/xen/byteorder.h
new file mode 100644
index 000000000000..2b9b97044478
--- /dev/null
+++ b/xen/include/xen/byteorder.h
@@ -0,0 +1,44 @@ 
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#ifndef XEN_BYTEORDER_H
+#define XEN_BYTEORDER_H
+
+#include <xen/byteswap.h>
+#include <xen/stdint.h>
+
+#if defined(__LITTLE_ENDIAN)
+
+# define cpu_to_le64(x) ((uint64_t)(x))
+# define le64_to_cpu(x) ((uint64_t)(x))
+# define cpu_to_le32(x) ((uint32_t)(x))
+# define le32_to_cpu(x) ((uint32_t)(x))
+# define cpu_to_le16(x) ((uint16_t)(x))
+# define le16_to_cpu(x) ((uint16_t)(x))
+
+# define cpu_to_be64(x) bswap64(x)
+# define be64_to_cpu(x) bswap64(x)
+# define cpu_to_be32(x) bswap32(x)
+# define be32_to_cpu(x) bswap32(x)
+# define cpu_to_be16(x) bswap16(x)
+# define be16_to_cpu(x) bswap16(x)
+
+#elif defined(__BIG_ENDIAN)
+
+# define cpu_to_le64(x) bswap64(x)
+# define le64_to_cpu(x) bswap64(x)
+# define cpu_to_le32(x) bswap32(x)
+# define le32_to_cpu(x) bswap32(x)
+# define cpu_to_le16(x) bswap16(x)
+# define le16_to_cpu(x) bswap16(x)
+
+# define cpu_to_be64(x) ((uint64_t)(x))
+# define be64_to_cpu(x) ((uint64_t)(x))
+# define cpu_to_be32(x) ((uint32_t)(x))
+# define be32_to_cpu(x) ((uint32_t)(x))
+# define cpu_to_be16(x) ((uint16_t)(x))
+# define be16_to_cpu(x) ((uint16_t)(x))
+
+#else
+# error Unknown Endianness
+#endif /* __*_ENDIAN */
+
+#endif /* XEN_BYTEORDER_H */
diff --git a/xen/include/xen/byteorder/big_endian.h b/xen/include/xen/byteorder/big_endian.h
index ce395a17f64b..512291c76f1b 100644
--- a/xen/include/xen/byteorder/big_endian.h
+++ b/xen/include/xen/byteorder/big_endian.h
@@ -1,13 +1,6 @@ 
 #ifndef __XEN_BYTEORDER_BIG_ENDIAN_H__
 #define __XEN_BYTEORDER_BIG_ENDIAN_H__
 
-#ifndef __BIG_ENDIAN
-#define __BIG_ENDIAN 4321
-#endif
-#ifndef __BIG_ENDIAN_BITFIELD
-#define __BIG_ENDIAN_BITFIELD
-#endif
-
 #include <xen/types.h>
 #include <xen/byteorder/swab.h>
 
diff --git a/xen/include/xen/byteorder/little_endian.h b/xen/include/xen/byteorder/little_endian.h
index 8b118afba5e3..bd1afc6a67c3 100644
--- a/xen/include/xen/byteorder/little_endian.h
+++ b/xen/include/xen/byteorder/little_endian.h
@@ -1,13 +1,6 @@ 
 #ifndef __XEN_BYTEORDER_LITTLE_ENDIAN_H__
 #define __XEN_BYTEORDER_LITTLE_ENDIAN_H__
 
-#ifndef __LITTLE_ENDIAN
-#define __LITTLE_ENDIAN 1234
-#endif
-#ifndef __LITTLE_ENDIAN_BITFIELD
-#define __LITTLE_ENDIAN_BITFIELD
-#endif
-
 #include <xen/types.h>
 #include <xen/byteorder/swab.h>
 
diff --git a/xen/include/xen/byteswap.h b/xen/include/xen/byteswap.h
new file mode 100644
index 000000000000..46d93f88eac9
--- /dev/null
+++ b/xen/include/xen/byteswap.h
@@ -0,0 +1,15 @@ 
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#ifndef XEN_BYTESWAP_H
+#define XEN_BYTESWAP_H
+
+#define bswap16(x) __builtin_bswap16(x)
+#define bswap32(x) __builtin_bswap32(x)
+#define bswap64(x) __builtin_bswap64(x)
+
+#if BITS_PER_LONG == 64
+# define bswapl(x) bswap64(x)
+#elif BITS_PER_LONG == 32
+# define bswapl(x) bswap32(x)
+#endif
+
+#endif /* XEN_BYTESWAP_H */
diff --git a/xen/include/xen/config.h b/xen/include/xen/config.h
index 7d43159efb56..1d7195066c08 100644
--- a/xen/include/xen/config.h
+++ b/xen/include/xen/config.h
@@ -108,4 +108,12 @@ 
 /* It is assumed that sizeof(void *) == __alignof(void *) */
 #define POINTER_ALIGN   __SIZEOF_POINTER__
 
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+# define __LITTLE_ENDIAN
+# define __LITTLE_ENDIAN_BITFIELD
+#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+# define __BIG_ENDIAN
+# define __BIG_ENDIAN_BITFIELD
+#endif
+
 #endif /* __XEN_CONFIG_H__ */