From: Yury Norov <ynorov@nvidia.com>
To: Paul Walmsley <pjw@kernel.org>,
Palmer Dabbelt <palmer@dabbelt.com>,
Albert Ou <aou@eecs.berkeley.edu>,
Alexandre Ghiti <alex@ghiti.fr>,
Yury Norov <yury.norov@gmail.com>,
Rasmus Villemoes <linux@rasmusvillemoes.dk>,
Arnd Bergmann <arnd@arndb.de>,
Andrew Lunn <andrew+netdev@lunn.ch>,
"David S. Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
Andrew Morton <akpm@linux-foundation.org>,
Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Jesper Dangaard Brouer <hawk@kernel.org>,
John Fastabend <john.fastabend@gmail.com>,
Stanislav Fomichev <sdf@fomichev.me>,
Jinjie Ruan <ruanjinjie@huawei.com>,
linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org,
linux-arch@vger.kernel.org, netdev@vger.kernel.org,
bpf@vger.kernel.org
Cc: Yury Norov <ynorov@nvidia.com>
Subject: [PATCH 3/6] bitops: Define generic __bitrev8/16/32 for reuse
Date: Thu, 30 Apr 2026 17:13:47 -0400 [thread overview]
Message-ID: <20260430211351.658193-4-ynorov@nvidia.com> (raw)
In-Reply-To: <20260430211351.658193-1-ynorov@nvidia.com>
From: Jinjie Ruan <ruanjinjie@huawei.com>
Define generic __bitrev8/16/32 using the implementation
in <linux/bitrev.h>, so they can be reused in <asm/bitrev.h>,
such as RISCV.
Reviewed-by: Yury Norov <ynorov@nvidia.com>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Signed-off-by: Yury Norov <ynorov@nvidia.com>
---
include/asm-generic/bitops/__bitrev.h | 25 +++++++++++++++++++++++++
include/linux/bitrev.h | 20 ++++----------------
2 files changed, 29 insertions(+), 16 deletions(-)
create mode 100644 include/asm-generic/bitops/__bitrev.h
diff --git a/include/asm-generic/bitops/__bitrev.h b/include/asm-generic/bitops/__bitrev.h
new file mode 100644
index 000000000000..f06af929678d
--- /dev/null
+++ b/include/asm-generic/bitops/__bitrev.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_GENERIC_BITOPS___BITREV_H_
+#define _ASM_GENERIC_BITOPS___BITREV_H_
+
+#ifdef CONFIG_GENERIC_BITREVERSE
+#include <asm/types.h>
+
+extern u8 const byte_rev_table[256];
+static __always_inline __attribute_const__ u8 generic___bitrev8(u8 byte)
+{
+ return byte_rev_table[byte];
+}
+
+static __always_inline __attribute_const__ u16 generic___bitrev16(u16 x)
+{
+ return (generic___bitrev8(x & 0xff) << 8) | generic___bitrev8(x >> 8);
+}
+
+static __always_inline __attribute_const__ u32 generic___bitrev32(u32 x)
+{
+ return (generic___bitrev16(x & 0xffff) << 16) | generic___bitrev16(x >> 16);
+}
+#endif /* CONFIG_GENERIC_BITREVERSE */
+
+#endif /* _ASM_GENERIC_BITOPS___BITREV_H_ */
diff --git a/include/linux/bitrev.h b/include/linux/bitrev.h
index d35b8ec1c485..11620a70e776 100644
--- a/include/linux/bitrev.h
+++ b/include/linux/bitrev.h
@@ -12,22 +12,10 @@
#define __bitrev8 __arch_bitrev8
#else
-extern u8 const byte_rev_table[256];
-static inline u8 __bitrev8(u8 byte)
-{
- return byte_rev_table[byte];
-}
-
-static inline u16 __bitrev16(u16 x)
-{
- return (__bitrev8(x & 0xff) << 8) | __bitrev8(x >> 8);
-}
-
-static inline u32 __bitrev32(u32 x)
-{
- return (__bitrev16(x & 0xffff) << 16) | __bitrev16(x >> 16);
-}
-
+#include <asm-generic/bitops/__bitrev.h>
+#define __bitrev32 generic___bitrev32
+#define __bitrev16 generic___bitrev16
+#define __bitrev8 generic___bitrev8
#endif /* CONFIG_HAVE_ARCH_BITREVERSE */
#define __bitrev8x4(x) (__bitrev32(swab32(x)))
--
2.51.0
next prev parent reply other threads:[~2026-04-30 21:14 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-04-30 21:13 [PATCH 0/6] lib: rework bitreverse Yury Norov
2026-04-30 21:13 ` [PATCH 1/6] lib: include crc32.h conditionally on CONFIG_CRC32 Yury Norov
2026-05-04 8:03 ` Arnd Bergmann
2026-05-04 12:43 ` David Laight
2026-05-04 16:46 ` Yury Norov
2026-05-04 17:18 ` Arnd Bergmann
2026-05-04 18:32 ` Yury Norov
2026-05-04 19:05 ` Arnd Bergmann
2026-04-30 21:13 ` [PATCH 2/6] lib/bitrev: Introduce GENERIC_BITREVERSE and cleanup Kconfig Yury Norov
2026-04-30 21:13 ` Yury Norov [this message]
2026-04-30 21:13 ` [PATCH 4/6] arch/riscv: Add bitrev.h file to support rev8 and brev8 Yury Norov
2026-04-30 21:13 ` [PATCH 5/6] lib: compile generic bitrev.c conditionally on GENERIC_BITREVERSE Yury Norov
2026-04-30 21:13 ` [PATCH 6/6] MAINTAINERS: BITOPS: include bitrev.[ch] Yury Norov
2026-05-02 1:40 ` [PATCH 0/6] lib: rework bitreverse Yury Norov
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