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authorLinus Torvalds <torvalds@linux-foundation.org>2025-09-29 19:01:08 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2025-09-29 19:01:08 -0700
commitcb7e3669c683669d93139184adff68a7d9000536 (patch)
treee59393a1a372a7a5d8fa5236bd6daf1fe45f2a02 /arch/riscv/include/asm/swab.h
parentMerge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/a... (diff)
parentriscv: errata: Fix the PAUSE Opcode for MIPS P8700 (diff)
downloadlinux-cb7e3669c683669d93139184adff68a7d9000536.tar.gz
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Merge tag 'riscv-for-linus-6.18-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux
Pull RISC-V updates from Paul Walmsley - Replacement of __ASSEMBLY__ with __ASSEMBLER__ in header files (other architectures have already merged this type of cleanup) - The introduction of ioremap_wc() for RISC-V - Cleanup of the RISC-V kprobes code to use mostly-extant macros rather than open code - A RISC-V kprobes unit test - An architecture-specific endianness swap macro set implementation, leveraging some dedicated RISC-V instructions for this purpose if they are available - The ability to identity and communicate to userspace the presence of a MIPS P8700-specific ISA extension, and to leverage its MIPS-specific PAUSE implementation in cpu_relax() - Several other miscellaneous cleanups * tag 'riscv-for-linus-6.18-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (39 commits) riscv: errata: Fix the PAUSE Opcode for MIPS P8700 riscv: hwprobe: Document MIPS xmipsexectl vendor extension riscv: hwprobe: Add MIPS vendor extension probing riscv: Add xmipsexectl instructions riscv: Add xmipsexectl as a vendor extension dt-bindings: riscv: Add xmipsexectl ISA extension description riscv: cpufeature: add validation for zfa, zfh and zfhmin perf: riscv: skip empty batches in counter start selftests: riscv: Add README for RISC-V KSelfTest riscv: sbi: Switch to new sys-off handler API riscv: Move vendor errata definitions to new header RISC-V: ACPI: enable parsing the BGRT table riscv: Enable ARCH_HAVE_NMI_SAFE_CMPXCHG riscv: pi: use 'targets' instead of extra-y in Makefile riscv: introduce asm/swab.h riscv: mmap(): use unsigned offset type in riscv_sys_mmap drivers/perf: riscv: Remove redundant ternary operators riscv: mm: Use mmu-type from FDT to limit SATP mode riscv: mm: Return intended SATP mode for noXlvl options riscv: kprobes: Remove duplication of RV_EXTRACT_ITYPE_IMM ...
Diffstat (limited to 'arch/riscv/include/asm/swab.h')
-rw-r--r--arch/riscv/include/asm/swab.h87
1 files changed, 87 insertions, 0 deletions
diff --git a/arch/riscv/include/asm/swab.h b/arch/riscv/include/asm/swab.h
new file mode 100644
index 000000000000..c1da22aa1326
--- /dev/null
+++ b/arch/riscv/include/asm/swab.h
@@ -0,0 +1,87 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef _ASM_RISCV_SWAB_H
+#define _ASM_RISCV_SWAB_H
+
+#include <linux/types.h>
+#include <linux/compiler.h>
+#include <asm/cpufeature-macros.h>
+#include <asm/hwcap.h>
+#include <asm-generic/swab.h>
+
+#if defined(CONFIG_TOOLCHAIN_HAS_ZBB) && defined(CONFIG_RISCV_ISA_ZBB) && !defined(NO_ALTERNATIVE)
+
+// Duplicated from include/uapi/linux/swab.h
+#define ___constant_swab16(x) ((__u16)( \
+ (((__u16)(x) & (__u16)0x00ffU) << 8) | \
+ (((__u16)(x) & (__u16)0xff00U) >> 8)))
+
+#define ___constant_swab32(x) ((__u32)( \
+ (((__u32)(x) & (__u32)0x000000ffUL) << 24) | \
+ (((__u32)(x) & (__u32)0x0000ff00UL) << 8) | \
+ (((__u32)(x) & (__u32)0x00ff0000UL) >> 8) | \
+ (((__u32)(x) & (__u32)0xff000000UL) >> 24)))
+
+#define ___constant_swab64(x) ((__u64)( \
+ (((__u64)(x) & (__u64)0x00000000000000ffULL) << 56) | \
+ (((__u64)(x) & (__u64)0x000000000000ff00ULL) << 40) | \
+ (((__u64)(x) & (__u64)0x0000000000ff0000ULL) << 24) | \
+ (((__u64)(x) & (__u64)0x00000000ff000000ULL) << 8) | \
+ (((__u64)(x) & (__u64)0x000000ff00000000ULL) >> 8) | \
+ (((__u64)(x) & (__u64)0x0000ff0000000000ULL) >> 24) | \
+ (((__u64)(x) & (__u64)0x00ff000000000000ULL) >> 40) | \
+ (((__u64)(x) & (__u64)0xff00000000000000ULL) >> 56)))
+
+#define ARCH_SWAB(size, value) \
+({ \
+ unsigned long x = value; \
+ \
+ if (riscv_has_extension_likely(RISCV_ISA_EXT_ZBB)) { \
+ asm volatile (".option push\n" \
+ ".option arch,+zbb\n" \
+ "rev8 %0, %1\n" \
+ ".option pop\n" \
+ : "=r" (x) : "r" (x)); \
+ x = x >> (BITS_PER_LONG - size); \
+ } else { \
+ x = ___constant_swab##size(value); \
+ } \
+ x; \
+})
+
+static __always_inline __u16 __arch_swab16(__u16 value)
+{
+ return ARCH_SWAB(16, value);
+}
+
+static __always_inline __u32 __arch_swab32(__u32 value)
+{
+ return ARCH_SWAB(32, value);
+}
+
+#ifdef CONFIG_64BIT
+static __always_inline __u64 __arch_swab64(__u64 value)
+{
+ return ARCH_SWAB(64, value);
+}
+#else
+static __always_inline __u64 __arch_swab64(__u64 value)
+{
+ __u32 h = value >> 32;
+ __u32 l = value & ((1ULL << 32) - 1);
+
+ return ((__u64)(__arch_swab32(l)) << 32) | ((__u64)(__arch_swab32(h)));
+}
+#endif
+
+#define __arch_swab64 __arch_swab64
+#define __arch_swab32 __arch_swab32
+#define __arch_swab16 __arch_swab16
+
+#undef ___constant_swab16
+#undef ___constant_swab32
+#undef ___constant_swab64
+
+#undef ARCH_SWAB
+
+#endif /* defined(CONFIG_TOOLCHAIN_HAS_ZBB) && defined(CONFIG_RISCV_ISA_ZBB) && !defined(NO_ALTERNATIVE) */
+#endif /* _ASM_RISCV_SWAB_H */