[PATCH v9 1/3] riscv: implement this_cpu operations
Yunhui Cui
cuiyunhui at bytedance.com
Sun Nov 8 03:04:04 PST 2026
RISC-V has no asm/percpu.h, so this_cpu_*() read-modify-write
operations use generic implementations that disable local interrupts.
Implement RISC-V-specific this_cpu operations with preemption disabled
to keep accesses on the current CPU. Native-width read-modify-write
operations use relaxed AMOs, while 8-bit and 16-bit read-modify-write
operations use Zabha when available or a local 32-bit LR/SC sequence
otherwise.
Link: https://lore.kernel.org/r/20260826010748.zphu3wh2hlm4t4o2@offworld
Tested-by: Davidlohr Bueso <dave at stgolabs.net>
Signed-off-by: Yunhui Cui <cuiyunhui at bytedance.com>
---
arch/riscv/include/asm/percpu.h | 569 ++++++++++++++++++++++++++++++++
1 file changed, 569 insertions(+)
create mode 100644 arch/riscv/include/asm/percpu.h
diff --git a/arch/riscv/include/asm/percpu.h b/arch/riscv/include/asm/percpu.h
new file mode 100644
index 0000000000000..280b122b9fe69
--- /dev/null
+++ b/arch/riscv/include/asm/percpu.h
@@ -0,0 +1,569 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#ifndef __ASM_PERCPU_H
+#define __ASM_PERCPU_H
+
+#include <linux/bits.h>
+#include <linux/preempt.h>
+
+#include <asm/alternative-macros.h>
+#include <asm/cmpxchg.h>
+#include <asm/cpufeature-macros.h>
+#include <asm/hwcap.h>
+#include <asm/irqflags.h>
+
+#define PERCPU_RW_OPS(sz) \
+static inline unsigned long __percpu_read_##sz(void *ptr) \
+{ \
+ return READ_ONCE(*(u##sz *)ptr); \
+} \
+ \
+static inline void __percpu_write_##sz(void *ptr, unsigned long val) \
+{ \
+ WRITE_ONCE(*(u##sz *)ptr, (u##sz)val); \
+}
+
+PERCPU_RW_OPS(8)
+PERCPU_RW_OPS(16)
+PERCPU_RW_OPS(32)
+
+#ifdef CONFIG_64BIT
+PERCPU_RW_OPS(64)
+#endif
+
+/*
+ * Use a real destination register instead of x0 even when the result is
+ * unused. Implementations may execute rd=x0 AMOs at a memory controller
+ * without returning the old value to the CPU. Value-returning AMOs are
+ * more likely to execute near the CPU, for example in the L1 cache. This
+ * better suits per-CPU data, which is typically accessed repeatedly by
+ * the same CPU.
+ *
+ * https://lore.kernel.org/r/e7d539ed-ced0-4b96-8ecd-048a5b803b85@paulmck-laptop
+ */
+#define __PERCPU_AMO_OP_CASE(sfx, name, sz, amo_insn) \
+static inline void \
+__percpu_##name##_amo_case_##sz(void *ptr, unsigned long val) \
+{ \
+ u##sz tmp; \
+ \
+ asm volatile ( \
+ "amo" #amo_insn #sfx " %[tmp], %[val], %[ptr]" \
+ : [ptr] "+A" (*(u##sz *)ptr), [tmp] "=r" (tmp) \
+ : [val] "r" ((u##sz)(val))); \
+}
+
+__PERCPU_AMO_OP_CASE(.w, add, 32, add)
+__PERCPU_AMO_OP_CASE(.w, and, 32, and)
+__PERCPU_AMO_OP_CASE(.w, or, 32, or)
+
+#ifdef CONFIG_64BIT
+__PERCPU_AMO_OP_CASE(.d, add, 64, add)
+__PERCPU_AMO_OP_CASE(.d, and, 64, and)
+__PERCPU_AMO_OP_CASE(.d, or, 64, or)
+#endif
+
+static inline u32 __percpu_add_return_amo_case_32(void *ptr, unsigned long val)
+{
+ register u32 ret;
+
+ asm volatile ("amoadd.w %[ret], %[val], %[ptr]"
+ : [ptr] "+A" (*(u32 *)ptr), [ret] "=r" (ret)
+ : [val] "r" ((u32)(val)));
+
+ return ret + val;
+}
+
+#ifdef CONFIG_64BIT
+static inline u64 __percpu_add_return_amo_case_64(void *ptr, unsigned long val)
+{
+ register u64 ret;
+
+ asm volatile ("amoadd.d %[ret], %[val], %[ptr]"
+ : [ptr] "+A" (*(u64 *)ptr), [ret] "=r" (ret)
+ : [val] "r" ((u64)(val)));
+
+ return ret + val;
+}
+#endif
+
+#define PERCPU_8_16_GET_SHIFT(ptr) (((unsigned long)(ptr) & 0x3) * BITS_PER_BYTE)
+#define PERCPU_8_16_GET_MASK(sz) GENMASK((sz) - 1, 0)
+#define PERCPU_8_16_GET_PTR32(ptr) ((u32 *)((unsigned long)(ptr) & ~0x3))
+
+static inline void __percpu_add_amo_case_8(void *ptr, unsigned long val)
+{
+ u8 tmp;
+
+ if (IS_ENABLED(CONFIG_RISCV_ISA_ZABHA) &&
+ riscv_has_extension_unlikely(RISCV_ISA_EXT_ZABHA)) {
+ asm volatile (".option push\n"
+ ".option arch, +zabha\n"
+ "amoadd.b %[tmp], %[val], %[ptr]\n"
+ ".option pop"
+ : [ptr] "+A" (*(u8 *)ptr), [tmp] "=r" (tmp)
+ : [val] "r" ((u8)(val & PERCPU_8_16_GET_MASK(8))));
+ } else {
+ u32 *ptr32 = PERCPU_8_16_GET_PTR32(ptr);
+ const unsigned long shift = PERCPU_8_16_GET_SHIFT(ptr);
+ const u32 mask = PERCPU_8_16_GET_MASK(8) << shift;
+ const u8 val_trunc = val & PERCPU_8_16_GET_MASK(8);
+ u32 old, new;
+ u8 field;
+
+ asm volatile ("0: lr.w %0, %2\n"
+ "and %3, %0, %4\n"
+ "srl %3, %3, %5\n"
+ "add %3, %3, %6\n"
+ "and %3, %3, %8\n"
+ "sll %3, %3, %5\n"
+ "and %1, %0, %7\n"
+ "or %1, %1, %3\n"
+ "sc.w %1, %1, %2\n"
+ "bnez %1, 0b\n"
+ : "=&r"(old), "=&r"(new), "+A"(*ptr32), "=&r"(field)
+ : "r"(mask), "r"(shift), "r"(val_trunc), "r"(~mask),
+ "r"(PERCPU_8_16_GET_MASK(8)));
+ }
+}
+
+static inline void __percpu_add_amo_case_16(void *ptr, unsigned long val)
+{
+ u16 tmp;
+
+ if (IS_ENABLED(CONFIG_RISCV_ISA_ZABHA) &&
+ riscv_has_extension_unlikely(RISCV_ISA_EXT_ZABHA)) {
+ asm volatile (".option push\n"
+ ".option arch, +zabha\n"
+ "amoadd.h %[tmp], %[val], %[ptr]\n"
+ ".option pop"
+ : [ptr] "+A" (*(u16 *)ptr), [tmp] "=r" (tmp)
+ : [val] "r" ((u16)(val & PERCPU_8_16_GET_MASK(16))));
+ } else {
+ u32 *ptr32 = PERCPU_8_16_GET_PTR32(ptr);
+ const unsigned long shift = PERCPU_8_16_GET_SHIFT(ptr);
+ const u32 mask = PERCPU_8_16_GET_MASK(16) << shift;
+ const u16 val_trunc = val & PERCPU_8_16_GET_MASK(16);
+ u32 old, new;
+ u16 field;
+
+ asm volatile ("0: lr.w %0, %2\n"
+ "and %3, %0, %4\n"
+ "srl %3, %3, %5\n"
+ "add %3, %3, %6\n"
+ "and %3, %3, %8\n"
+ "sll %3, %3, %5\n"
+ "and %1, %0, %7\n"
+ "or %1, %1, %3\n"
+ "sc.w %1, %1, %2\n"
+ "bnez %1, 0b\n"
+ : "=&r"(old), "=&r"(new), "+A"(*ptr32), "=&r"(field)
+ : "r"(mask), "r"(shift), "r"(val_trunc), "r"(~mask),
+ "r"(PERCPU_8_16_GET_MASK(16)));
+ }
+}
+
+static inline void __percpu_and_amo_case_8(void *ptr, unsigned long val)
+{
+ u8 tmp;
+
+ if (IS_ENABLED(CONFIG_RISCV_ISA_ZABHA) &&
+ riscv_has_extension_unlikely(RISCV_ISA_EXT_ZABHA)) {
+ asm volatile (".option push\n"
+ ".option arch, +zabha\n"
+ "amoand.b %[tmp], %[val], %[ptr]\n"
+ ".option pop"
+ : [ptr] "+A" (*(u8 *)ptr), [tmp] "=r" (tmp)
+ : [val] "r" ((u8)(val & PERCPU_8_16_GET_MASK(8))));
+ } else {
+ u32 *ptr32 = PERCPU_8_16_GET_PTR32(ptr);
+ const unsigned long shift = PERCPU_8_16_GET_SHIFT(ptr);
+ const u32 mask = PERCPU_8_16_GET_MASK(8) << shift;
+ const u8 val_trunc = val & PERCPU_8_16_GET_MASK(8);
+ u32 old, new;
+ u8 field;
+
+ asm volatile ("0: lr.w %0, %2\n"
+ "and %3, %0, %4\n"
+ "srl %3, %3, %5\n"
+ "and %3, %3, %6\n"
+ "and %3, %3, %8\n"
+ "sll %3, %3, %5\n"
+ "and %1, %0, %7\n"
+ "or %1, %1, %3\n"
+ "sc.w %1, %1, %2\n"
+ "bnez %1, 0b\n"
+ : "=&r"(old), "=&r"(new), "+A"(*ptr32), "=&r"(field)
+ : "r"(mask), "r"(shift), "r"(val_trunc), "r"(~mask),
+ "r"(PERCPU_8_16_GET_MASK(8)));
+ }
+}
+
+static inline void __percpu_and_amo_case_16(void *ptr, unsigned long val)
+{
+ u16 tmp;
+
+ if (IS_ENABLED(CONFIG_RISCV_ISA_ZABHA) &&
+ riscv_has_extension_unlikely(RISCV_ISA_EXT_ZABHA)) {
+ asm volatile (".option push\n"
+ ".option arch, +zabha\n"
+ "amoand.h %[tmp], %[val], %[ptr]\n"
+ ".option pop"
+ : [ptr] "+A" (*(u16 *)ptr), [tmp] "=r" (tmp)
+ : [val] "r" ((u16)(val & PERCPU_8_16_GET_MASK(16))));
+ } else {
+ u32 *ptr32 = PERCPU_8_16_GET_PTR32(ptr);
+ const unsigned long shift = PERCPU_8_16_GET_SHIFT(ptr);
+ const u32 mask = PERCPU_8_16_GET_MASK(16) << shift;
+ const u16 val_trunc = val & PERCPU_8_16_GET_MASK(16);
+ u32 old, new;
+ u16 field;
+
+ asm volatile ("0: lr.w %0, %2\n"
+ "and %3, %0, %4\n"
+ "srl %3, %3, %5\n"
+ "and %3, %3, %6\n"
+ "and %3, %3, %8\n"
+ "sll %3, %3, %5\n"
+ "and %1, %0, %7\n"
+ "or %1, %1, %3\n"
+ "sc.w %1, %1, %2\n"
+ "bnez %1, 0b\n"
+ : "=&r"(old), "=&r"(new), "+A"(*ptr32), "=&r"(field)
+ : "r"(mask), "r"(shift), "r"(val_trunc), "r"(~mask),
+ "r"(PERCPU_8_16_GET_MASK(16)));
+ }
+}
+
+static inline void __percpu_or_amo_case_8(void *ptr, unsigned long val)
+{
+ u8 tmp;
+
+ if (IS_ENABLED(CONFIG_RISCV_ISA_ZABHA) &&
+ riscv_has_extension_unlikely(RISCV_ISA_EXT_ZABHA)) {
+ asm volatile (".option push\n"
+ ".option arch, +zabha\n"
+ "amoor.b %[tmp], %[val], %[ptr]\n"
+ ".option pop"
+ : [ptr] "+A" (*(u8 *)ptr), [tmp] "=r" (tmp)
+ : [val] "r" ((u8)(val & PERCPU_8_16_GET_MASK(8))));
+ } else {
+ u32 *ptr32 = PERCPU_8_16_GET_PTR32(ptr);
+ const unsigned long shift = PERCPU_8_16_GET_SHIFT(ptr);
+ const u32 mask = PERCPU_8_16_GET_MASK(8) << shift;
+ const u8 val_trunc = val & PERCPU_8_16_GET_MASK(8);
+ u32 old, new;
+ u8 field;
+
+ asm volatile ("0: lr.w %0, %2\n"
+ "and %3, %0, %4\n"
+ "srl %3, %3, %5\n"
+ "or %3, %3, %6\n"
+ "and %3, %3, %8\n"
+ "sll %3, %3, %5\n"
+ "and %1, %0, %7\n"
+ "or %1, %1, %3\n"
+ "sc.w %1, %1, %2\n"
+ "bnez %1, 0b\n"
+ : "=&r"(old), "=&r"(new), "+A"(*ptr32), "=&r"(field)
+ : "r"(mask), "r"(shift), "r"(val_trunc), "r"(~mask),
+ "r"(PERCPU_8_16_GET_MASK(8)));
+ }
+}
+
+static inline void __percpu_or_amo_case_16(void *ptr, unsigned long val)
+{
+ u16 tmp;
+
+ if (IS_ENABLED(CONFIG_RISCV_ISA_ZABHA) &&
+ riscv_has_extension_unlikely(RISCV_ISA_EXT_ZABHA)) {
+ asm volatile (".option push\n"
+ ".option arch, +zabha\n"
+ "amoor.h %[tmp], %[val], %[ptr]\n"
+ ".option pop"
+ : [ptr] "+A" (*(u16 *)ptr), [tmp] "=r" (tmp)
+ : [val] "r" ((u16)(val & PERCPU_8_16_GET_MASK(16))));
+ } else {
+ u32 *ptr32 = PERCPU_8_16_GET_PTR32(ptr);
+ const unsigned long shift = PERCPU_8_16_GET_SHIFT(ptr);
+ const u32 mask = PERCPU_8_16_GET_MASK(16) << shift;
+ const u16 val_trunc = val & PERCPU_8_16_GET_MASK(16);
+ u32 old, new;
+ u16 field;
+
+ asm volatile ("0: lr.w %0, %2\n"
+ "and %3, %0, %4\n"
+ "srl %3, %3, %5\n"
+ "or %3, %3, %6\n"
+ "and %3, %3, %8\n"
+ "sll %3, %3, %5\n"
+ "and %1, %0, %7\n"
+ "or %1, %1, %3\n"
+ "sc.w %1, %1, %2\n"
+ "bnez %1, 0b\n"
+ : "=&r"(old), "=&r"(new), "+A"(*ptr32), "=&r"(field)
+ : "r"(mask), "r"(shift), "r"(val_trunc), "r"(~mask),
+ "r"(PERCPU_8_16_GET_MASK(16)));
+ }
+}
+
+static inline u8 __percpu_add_return_amo_case_8(void *ptr, unsigned long val)
+{
+ if (IS_ENABLED(CONFIG_RISCV_ISA_ZABHA) &&
+ riscv_has_extension_unlikely(RISCV_ISA_EXT_ZABHA)) {
+ register u8 ret;
+
+ asm volatile (".option push\n"
+ ".option arch, +zabha\n"
+ "amoadd.b %[ret], %[val], %[ptr]\n"
+ ".option pop"
+ : [ptr] "+A"(*(u8 *)ptr), [ret] "=r"(ret)
+ : [val] "r"((u8)(val & PERCPU_8_16_GET_MASK(8))));
+ return ret + (u8)(val & PERCPU_8_16_GET_MASK(8));
+ }
+
+ {
+ u32 *ptr32 = PERCPU_8_16_GET_PTR32(ptr);
+ const unsigned long shift = PERCPU_8_16_GET_SHIFT(ptr);
+ const u32 mask = PERCPU_8_16_GET_MASK(8) << shift;
+ const u32 inv_mask = ~mask;
+ const u8 val_trunc = val & PERCPU_8_16_GET_MASK(8);
+ u32 old, new, field;
+
+ asm volatile ("0: lr.w %0, %3\n"
+ "and %1, %0, %4\n"
+ "srl %1, %1, %5\n"
+ "add %1, %1, %6\n"
+ "and %1, %1, %7\n"
+ "sll %1, %1, %5\n"
+ "and %2, %0, %8\n"
+ "or %2, %2, %1\n"
+ "sc.w %2, %2, %3\n"
+ "bnez %2, 0b\n"
+ : "=&r"(old), "=&r"(field), "=&r"(new), "+A"(*ptr32)
+ : "r"(mask), "r"(shift), "r"(val_trunc),
+ "r"(PERCPU_8_16_GET_MASK(8)), "r"(inv_mask));
+ return field >> shift;
+ }
+}
+
+static inline u16 __percpu_add_return_amo_case_16(void *ptr, unsigned long val)
+{
+ if (IS_ENABLED(CONFIG_RISCV_ISA_ZABHA) &&
+ riscv_has_extension_unlikely(RISCV_ISA_EXT_ZABHA)) {
+ register u16 ret;
+
+ asm volatile (".option push\n"
+ ".option arch, +zabha\n"
+ "amoadd.h %[ret], %[val], %[ptr]\n"
+ ".option pop"
+ : [ptr] "+A"(*(u16 *)ptr), [ret] "=r"(ret)
+ : [val] "r"((u16)(val & PERCPU_8_16_GET_MASK(16))));
+ return ret + (u16)(val & PERCPU_8_16_GET_MASK(16));
+ }
+
+ {
+ u32 *ptr32 = PERCPU_8_16_GET_PTR32(ptr);
+ const unsigned long shift = PERCPU_8_16_GET_SHIFT(ptr);
+ const u32 mask = PERCPU_8_16_GET_MASK(16) << shift;
+ const u32 inv_mask = ~mask;
+ const u16 val_trunc = val & PERCPU_8_16_GET_MASK(16);
+ u32 old, new, field;
+
+ asm volatile ("0: lr.w %0, %3\n"
+ "and %1, %0, %4\n"
+ "srl %1, %1, %5\n"
+ "add %1, %1, %6\n"
+ "and %1, %1, %7\n"
+ "sll %1, %1, %5\n"
+ "and %2, %0, %8\n"
+ "or %2, %2, %1\n"
+ "sc.w %2, %2, %3\n"
+ "bnez %2, 0b\n"
+ : "=&r"(old), "=&r"(field), "=&r"(new), "+A"(*ptr32)
+ : "r"(mask), "r"(shift), "r"(val_trunc),
+ "r"(PERCPU_8_16_GET_MASK(16)), "r"(inv_mask));
+ return field >> shift;
+ }
+}
+
+/*
+ * Put arch_cmpxchg_relaxed() behind a function boundary to isolate its macro
+ * locals from those at the call site. asm-generic implements
+ * this_cpu_try_cmpxchg_N() using this_cpu_cmpxchg_N() and a local named __old.
+ * RISC-V's _arch_cmpxchg() also declares __old, so expanding it in the caller's
+ * scope would turn its initializer into "__old = (__old)" and read the
+ * uninitialized inner variable.
+ *
+ * __always_inline avoids an out-of-line call.
+ * _pcp_protect_cmpxchg_return() provides the instrument_atomic_read_write()
+ * hook that cmpxchg_relaxed() would otherwise provide.
+ */
+#define PERCPU_CMPXCHG_OP(sz) \
+static __always_inline unsigned long \
+__percpu_cmpxchg_case_##sz(void *ptr, unsigned long old, \
+ unsigned long new) \
+{ \
+ return arch_cmpxchg_relaxed((u##sz *)ptr, (u##sz)old, \
+ (u##sz)new); \
+}
+
+PERCPU_CMPXCHG_OP(8)
+PERCPU_CMPXCHG_OP(16)
+PERCPU_CMPXCHG_OP(32)
+
+#ifdef CONFIG_64BIT
+PERCPU_CMPXCHG_OP(64)
+#endif
+
+#define _pcp_protect(op, pcp, ...) \
+({ \
+ preempt_disable_notrace(); \
+ op(raw_cpu_ptr(&(pcp)), __VA_ARGS__); \
+ preempt_enable_notrace(); \
+})
+
+#define _pcp_protect_return(op, pcp, args...) \
+({ \
+ typeof(pcp) __retval; \
+ preempt_disable_notrace(); \
+ __retval = (typeof(pcp))op(raw_cpu_ptr(&(pcp)), ##args); \
+ preempt_enable_notrace(); \
+ __retval; \
+})
+
+#define _pcp_protect_cmpxchg_return(op, pcp, old, new) \
+({ \
+ typeof(pcp) __retval; \
+ typeof(pcp) *__pcp_ptr; \
+ \
+ preempt_disable_notrace(); \
+ __pcp_ptr = raw_cpu_ptr(&(pcp)); \
+ instrument_atomic_read_write(__pcp_ptr, sizeof(*__pcp_ptr)); \
+ __retval = (typeof(pcp))op(__pcp_ptr, (unsigned long)(old), \
+ (unsigned long)(new)); \
+ preempt_enable_notrace(); \
+ __retval; \
+})
+
+#define this_cpu_read_1(pcp) _pcp_protect_return(__percpu_read_8, pcp)
+#define this_cpu_read_2(pcp) _pcp_protect_return(__percpu_read_16, pcp)
+#define this_cpu_read_4(pcp) _pcp_protect_return(__percpu_read_32, pcp)
+
+#ifdef CONFIG_64BIT
+#define this_cpu_read_8(pcp) _pcp_protect_return(__percpu_read_64, pcp)
+#endif
+
+#define this_cpu_write_1(pcp, val) _pcp_protect(__percpu_write_8, pcp, (unsigned long)val)
+#define this_cpu_write_2(pcp, val) _pcp_protect(__percpu_write_16, pcp, (unsigned long)val)
+#define this_cpu_write_4(pcp, val) _pcp_protect(__percpu_write_32, pcp, (unsigned long)val)
+
+#ifdef CONFIG_64BIT
+#define this_cpu_write_8(pcp, val) _pcp_protect(__percpu_write_64, pcp, (unsigned long)val)
+#endif
+
+#define this_cpu_add_1(pcp, val) _pcp_protect(__percpu_add_amo_case_8, pcp, val)
+#define this_cpu_add_2(pcp, val) _pcp_protect(__percpu_add_amo_case_16, pcp, val)
+#define this_cpu_add_4(pcp, val) _pcp_protect(__percpu_add_amo_case_32, pcp, val)
+
+#ifdef CONFIG_64BIT
+#define this_cpu_add_8(pcp, val) _pcp_protect(__percpu_add_amo_case_64, pcp, val)
+#endif
+
+#define this_cpu_add_return_1(pcp, val) \
+_pcp_protect_return(__percpu_add_return_amo_case_8, pcp, val)
+
+#define this_cpu_add_return_2(pcp, val) \
+_pcp_protect_return(__percpu_add_return_amo_case_16, pcp, val)
+
+#define this_cpu_add_return_4(pcp, val) \
+_pcp_protect_return(__percpu_add_return_amo_case_32, pcp, val)
+
+#ifdef CONFIG_64BIT
+#define this_cpu_add_return_8(pcp, val) \
+_pcp_protect_return(__percpu_add_return_amo_case_64, pcp, val)
+#endif
+
+#define this_cpu_and_1(pcp, val) _pcp_protect(__percpu_and_amo_case_8, pcp, val)
+#define this_cpu_and_2(pcp, val) _pcp_protect(__percpu_and_amo_case_16, pcp, val)
+#define this_cpu_and_4(pcp, val) _pcp_protect(__percpu_and_amo_case_32, pcp, val)
+
+#ifdef CONFIG_64BIT
+#define this_cpu_and_8(pcp, val) _pcp_protect(__percpu_and_amo_case_64, pcp, val)
+#endif
+
+#define this_cpu_or_1(pcp, val) _pcp_protect(__percpu_or_amo_case_8, pcp, val)
+#define this_cpu_or_2(pcp, val) _pcp_protect(__percpu_or_amo_case_16, pcp, val)
+#define this_cpu_or_4(pcp, val) _pcp_protect(__percpu_or_amo_case_32, pcp, val)
+
+#ifdef CONFIG_64BIT
+#define this_cpu_or_8(pcp, val) _pcp_protect(__percpu_or_amo_case_64, pcp, val)
+#endif
+
+#define this_cpu_xchg_1(pcp, val) _pcp_protect_return(xchg_relaxed, pcp, val)
+#define this_cpu_xchg_2(pcp, val) _pcp_protect_return(xchg_relaxed, pcp, val)
+#define this_cpu_xchg_4(pcp, val) _pcp_protect_return(xchg_relaxed, pcp, val)
+
+#ifdef CONFIG_64BIT
+#define this_cpu_xchg_8(pcp, val) _pcp_protect_return(xchg_relaxed, pcp, val)
+#endif
+
+#define this_cpu_cmpxchg_1(pcp, o, n) \
+ _pcp_protect_cmpxchg_return(__percpu_cmpxchg_case_8, pcp, o, n)
+
+#define this_cpu_cmpxchg_2(pcp, o, n) \
+ _pcp_protect_cmpxchg_return(__percpu_cmpxchg_case_16, pcp, o, n)
+
+#define this_cpu_cmpxchg_4(pcp, o, n) \
+ _pcp_protect_cmpxchg_return(__percpu_cmpxchg_case_32, pcp, o, n)
+
+#ifdef CONFIG_64BIT
+#define this_cpu_cmpxchg_8(pcp, o, n) \
+ _pcp_protect_cmpxchg_return(__percpu_cmpxchg_case_64, pcp, o, n)
+
+#define this_cpu_cmpxchg64(pcp, o, n) this_cpu_cmpxchg_8(pcp, o, n)
+#endif
+
+#ifdef system_has_cmpxchg128
+static inline u128 __percpu_generic_cmpxchg128(void *ptr, u128 old_val,
+ u128 new_val)
+{
+ unsigned long flags;
+ u128 *p = ptr;
+ u128 ret;
+
+ flags = arch_local_irq_save();
+ ret = *p;
+ if (ret == old_val)
+ *p = new_val;
+ arch_local_irq_restore(flags);
+
+ return ret;
+}
+
+#define this_cpu_cmpxchg128(pcp, o, n) \
+({ \
+ u128 old__ = (o), new__ = (n), ret__; \
+ typeof(pcp) *ptr__; \
+ \
+ preempt_disable_notrace(); \
+ ptr__ = raw_cpu_ptr(&(pcp)); \
+ if (system_has_cmpxchg128()) \
+ ret__ = cmpxchg128_local(ptr__, old__, new__); \
+ else \
+ ret__ = __percpu_generic_cmpxchg128(ptr__, old__, new__); \
+ preempt_enable_notrace(); \
+ ret__; \
+})
+#endif
+
+#undef PERCPU_RW_OPS
+#undef __PERCPU_AMO_OP_CASE
+#undef PERCPU_8_16_GET_SHIFT
+#undef PERCPU_8_16_GET_MASK
+#undef PERCPU_8_16_GET_PTR32
+#undef PERCPU_CMPXCHG_OP
+
+#include <asm-generic/percpu.h>
+
+#endif /* __ASM_PERCPU_H */
base-commit: ddfe51b0a0f5dc9e415cc2c8ad8db17532dd426b
--
2.39.5
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