2023-05-15 08:08:21

by Peter Zijlstra

[permalink] [raw]
Subject: [PATCH v3 10/11] arch: Remove cmpxchg_double

No moar users, remove the monster.

Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
---
Documentation/core-api/this_cpu_ops.rst | 2 -
arch/arm64/include/asm/atomic_ll_sc.h | 33 ----------------
arch/arm64/include/asm/atomic_lse.h | 36 ------------------
arch/arm64/include/asm/cmpxchg.h | 46 -----------------------
arch/arm64/include/asm/percpu.h | 10 -----
arch/s390/include/asm/cmpxchg.h | 34 -----------------
arch/s390/include/asm/percpu.h | 18 ---------
arch/x86/include/asm/cmpxchg.h | 25 ------------
arch/x86/include/asm/cmpxchg_32.h | 1
arch/x86/include/asm/cmpxchg_64.h | 1
arch/x86/include/asm/percpu.h | 41 --------------------
include/asm-generic/percpu.h | 58 -----------------------------
include/linux/atomic/atomic-instrumented.h | 17 --------
include/linux/percpu-defs.h | 38 -------------------
scripts/atomic/gen-atomic-instrumented.sh | 15 ++-----
15 files changed, 5 insertions(+), 370 deletions(-)

--- a/Documentation/core-api/this_cpu_ops.rst
+++ b/Documentation/core-api/this_cpu_ops.rst
@@ -53,7 +53,6 @@ are defined. These operations can be use
this_cpu_add_return(pcp, val)
this_cpu_xchg(pcp, nval)
this_cpu_cmpxchg(pcp, oval, nval)
- this_cpu_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
this_cpu_sub(pcp, val)
this_cpu_inc(pcp)
this_cpu_dec(pcp)
@@ -242,7 +241,6 @@ modifies the variable, then RMW actions
__this_cpu_add_return(pcp, val)
__this_cpu_xchg(pcp, nval)
__this_cpu_cmpxchg(pcp, oval, nval)
- __this_cpu_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
__this_cpu_sub(pcp, val)
__this_cpu_inc(pcp)
__this_cpu_dec(pcp)
--- a/arch/arm64/include/asm/atomic_ll_sc.h
+++ b/arch/arm64/include/asm/atomic_ll_sc.h
@@ -294,39 +294,6 @@ __CMPXCHG_CASE( , , mb_, 64, dmb ish,

#undef __CMPXCHG_CASE

-#define __CMPXCHG_DBL(name, mb, rel, cl) \
-static __always_inline long \
-__ll_sc__cmpxchg_double##name(unsigned long old1, \
- unsigned long old2, \
- unsigned long new1, \
- unsigned long new2, \
- volatile void *ptr) \
-{ \
- unsigned long tmp, ret; \
- \
- asm volatile("// __cmpxchg_double" #name "\n" \
- " prfm pstl1strm, %2\n" \
- "1: ldxp %0, %1, %2\n" \
- " eor %0, %0, %3\n" \
- " eor %1, %1, %4\n" \
- " orr %1, %0, %1\n" \
- " cbnz %1, 2f\n" \
- " st" #rel "xp %w0, %5, %6, %2\n" \
- " cbnz %w0, 1b\n" \
- " " #mb "\n" \
- "2:" \
- : "=&r" (tmp), "=&r" (ret), "+Q" (*(__uint128_t *)ptr) \
- : "r" (old1), "r" (old2), "r" (new1), "r" (new2) \
- : cl); \
- \
- return ret; \
-}
-
-__CMPXCHG_DBL( , , , )
-__CMPXCHG_DBL(_mb, dmb ish, l, "memory")
-
-#undef __CMPXCHG_DBL
-
union __u128_halves {
u128 full;
struct {
--- a/arch/arm64/include/asm/atomic_lse.h
+++ b/arch/arm64/include/asm/atomic_lse.h
@@ -281,42 +281,6 @@ __CMPXCHG_CASE(x, , mb_, 64, al, "memo

#undef __CMPXCHG_CASE

-#define __CMPXCHG_DBL(name, mb, cl...) \
-static __always_inline long \
-__lse__cmpxchg_double##name(unsigned long old1, \
- unsigned long old2, \
- unsigned long new1, \
- unsigned long new2, \
- volatile void *ptr) \
-{ \
- unsigned long oldval1 = old1; \
- unsigned long oldval2 = old2; \
- register unsigned long x0 asm ("x0") = old1; \
- register unsigned long x1 asm ("x1") = old2; \
- register unsigned long x2 asm ("x2") = new1; \
- register unsigned long x3 asm ("x3") = new2; \
- register unsigned long x4 asm ("x4") = (unsigned long)ptr; \
- \
- asm volatile( \
- __LSE_PREAMBLE \
- " casp" #mb "\t%[old1], %[old2], %[new1], %[new2], %[v]\n"\
- " eor %[old1], %[old1], %[oldval1]\n" \
- " eor %[old2], %[old2], %[oldval2]\n" \
- " orr %[old1], %[old1], %[old2]" \
- : [old1] "+&r" (x0), [old2] "+&r" (x1), \
- [v] "+Q" (*(__uint128_t *)ptr) \
- : [new1] "r" (x2), [new2] "r" (x3), [ptr] "r" (x4), \
- [oldval1] "r" (oldval1), [oldval2] "r" (oldval2) \
- : cl); \
- \
- return x0; \
-}
-
-__CMPXCHG_DBL( , )
-__CMPXCHG_DBL(_mb, al, "memory")
-
-#undef __CMPXCHG_DBL
-
#define __CMPXCHG128(name, mb, cl...) \
static __always_inline u128 \
__lse__cmpxchg128##name(volatile u128 *ptr, u128 old, u128 new) \
--- a/arch/arm64/include/asm/cmpxchg.h
+++ b/arch/arm64/include/asm/cmpxchg.h
@@ -130,22 +130,6 @@ __CMPXCHG_CASE(mb_, 64)

#undef __CMPXCHG_CASE

-#define __CMPXCHG_DBL(name) \
-static inline long __cmpxchg_double##name(unsigned long old1, \
- unsigned long old2, \
- unsigned long new1, \
- unsigned long new2, \
- volatile void *ptr) \
-{ \
- return __lse_ll_sc_body(_cmpxchg_double##name, \
- old1, old2, new1, new2, ptr); \
-}
-
-__CMPXCHG_DBL( )
-__CMPXCHG_DBL(_mb)
-
-#undef __CMPXCHG_DBL
-
#define __CMPXCHG128(name) \
static inline u128 __cmpxchg128##name(volatile u128 *ptr, \
u128 old, u128 new) \
@@ -211,36 +195,6 @@ __CMPXCHG_GEN(_mb)
#define arch_cmpxchg64 arch_cmpxchg
#define arch_cmpxchg64_local arch_cmpxchg_local

-/* cmpxchg_double */
-#define system_has_cmpxchg_double() 1
-
-#define __cmpxchg_double_check(ptr1, ptr2) \
-({ \
- if (sizeof(*(ptr1)) != 8) \
- BUILD_BUG(); \
- VM_BUG_ON((unsigned long *)(ptr2) - (unsigned long *)(ptr1) != 1); \
-})
-
-#define arch_cmpxchg_double(ptr1, ptr2, o1, o2, n1, n2) \
-({ \
- int __ret; \
- __cmpxchg_double_check(ptr1, ptr2); \
- __ret = !__cmpxchg_double_mb((unsigned long)(o1), (unsigned long)(o2), \
- (unsigned long)(n1), (unsigned long)(n2), \
- ptr1); \
- __ret; \
-})
-
-#define arch_cmpxchg_double_local(ptr1, ptr2, o1, o2, n1, n2) \
-({ \
- int __ret; \
- __cmpxchg_double_check(ptr1, ptr2); \
- __ret = !__cmpxchg_double((unsigned long)(o1), (unsigned long)(o2), \
- (unsigned long)(n1), (unsigned long)(n2), \
- ptr1); \
- __ret; \
-})
-
/* cmpxchg128 */
#define system_has_cmpxchg128() 1

--- a/arch/arm64/include/asm/percpu.h
+++ b/arch/arm64/include/asm/percpu.h
@@ -145,16 +145,6 @@ PERCPU_RET_OP(add, add, ldadd)
* preemption point when TIF_NEED_RESCHED gets set while preemption is
* disabled.
*/
-#define this_cpu_cmpxchg_double_8(ptr1, ptr2, o1, o2, n1, n2) \
-({ \
- int __ret; \
- preempt_disable_notrace(); \
- __ret = cmpxchg_double_local( raw_cpu_ptr(&(ptr1)), \
- raw_cpu_ptr(&(ptr2)), \
- o1, o2, n1, n2); \
- preempt_enable_notrace(); \
- __ret; \
-})

#define _pcp_protect(op, pcp, ...) \
({ \
--- a/arch/s390/include/asm/cmpxchg.h
+++ b/arch/s390/include/asm/cmpxchg.h
@@ -190,40 +190,6 @@ static __always_inline unsigned long __c
#define arch_cmpxchg_local arch_cmpxchg
#define arch_cmpxchg64_local arch_cmpxchg

-#define system_has_cmpxchg_double() 1
-
-static __always_inline int __cmpxchg_double(unsigned long p1, unsigned long p2,
- unsigned long o1, unsigned long o2,
- unsigned long n1, unsigned long n2)
-{
- union register_pair old = { .even = o1, .odd = o2, };
- union register_pair new = { .even = n1, .odd = n2, };
- int cc;
-
- asm volatile(
- " cdsg %[old],%[new],%[ptr]\n"
- " ipm %[cc]\n"
- " srl %[cc],28\n"
- : [cc] "=&d" (cc), [old] "+&d" (old.pair)
- : [new] "d" (new.pair),
- [ptr] "QS" (*(unsigned long *)p1), "Q" (*(unsigned long *)p2)
- : "memory", "cc");
- return !cc;
-}
-
-#define arch_cmpxchg_double(p1, p2, o1, o2, n1, n2) \
-({ \
- typeof(p1) __p1 = (p1); \
- typeof(p2) __p2 = (p2); \
- \
- BUILD_BUG_ON(sizeof(*(p1)) != sizeof(long)); \
- BUILD_BUG_ON(sizeof(*(p2)) != sizeof(long)); \
- VM_BUG_ON((unsigned long)((__p1) + 1) != (unsigned long)(__p2));\
- __cmpxchg_double((unsigned long)__p1, (unsigned long)__p2, \
- (unsigned long)(o1), (unsigned long)(o2), \
- (unsigned long)(n1), (unsigned long)(n2)); \
-})
-
#define system_has_cmpxchg128() 1

static __always_inline u128 arch_cmpxchg128(volatile u128 *ptr, u128 old, u128 new)
--- a/arch/s390/include/asm/percpu.h
+++ b/arch/s390/include/asm/percpu.h
@@ -180,24 +180,6 @@
#define this_cpu_xchg_4(pcp, nval) arch_this_cpu_xchg(pcp, nval)
#define this_cpu_xchg_8(pcp, nval) arch_this_cpu_xchg(pcp, nval)

-#define arch_this_cpu_cmpxchg_double(pcp1, pcp2, o1, o2, n1, n2) \
-({ \
- typeof(pcp1) *p1__; \
- typeof(pcp2) *p2__; \
- int ret__; \
- \
- preempt_disable_notrace(); \
- p1__ = raw_cpu_ptr(&(pcp1)); \
- p2__ = raw_cpu_ptr(&(pcp2)); \
- ret__ = __cmpxchg_double((unsigned long)p1__, (unsigned long)p2__, \
- (unsigned long)(o1), (unsigned long)(o2), \
- (unsigned long)(n1), (unsigned long)(n2)); \
- preempt_enable_notrace(); \
- ret__; \
-})
-
-#define this_cpu_cmpxchg_double_8 arch_this_cpu_cmpxchg_double
-
#include <asm-generic/percpu.h>

#endif /* __ARCH_S390_PERCPU__ */
--- a/arch/x86/include/asm/cmpxchg.h
+++ b/arch/x86/include/asm/cmpxchg.h
@@ -239,29 +239,4 @@ extern void __add_wrong_size(void)
#define __xadd(ptr, inc, lock) __xchg_op((ptr), (inc), xadd, lock)
#define xadd(ptr, inc) __xadd((ptr), (inc), LOCK_PREFIX)

-#define __cmpxchg_double(pfx, p1, p2, o1, o2, n1, n2) \
-({ \
- bool __ret; \
- __typeof__(*(p1)) __old1 = (o1), __new1 = (n1); \
- __typeof__(*(p2)) __old2 = (o2), __new2 = (n2); \
- BUILD_BUG_ON(sizeof(*(p1)) != sizeof(long)); \
- BUILD_BUG_ON(sizeof(*(p2)) != sizeof(long)); \
- VM_BUG_ON((unsigned long)(p1) % (2 * sizeof(long))); \
- VM_BUG_ON((unsigned long)((p1) + 1) != (unsigned long)(p2)); \
- asm volatile(pfx "cmpxchg%c5b %1" \
- CC_SET(e) \
- : CC_OUT(e) (__ret), \
- "+m" (*(p1)), "+m" (*(p2)), \
- "+a" (__old1), "+d" (__old2) \
- : "i" (2 * sizeof(long)), \
- "b" (__new1), "c" (__new2)); \
- __ret; \
-})
-
-#define arch_cmpxchg_double(p1, p2, o1, o2, n1, n2) \
- __cmpxchg_double(LOCK_PREFIX, p1, p2, o1, o2, n1, n2)
-
-#define arch_cmpxchg_double_local(p1, p2, o1, o2, n1, n2) \
- __cmpxchg_double(, p1, p2, o1, o2, n1, n2)
-
#endif /* ASM_X86_CMPXCHG_H */
--- a/arch/x86/include/asm/cmpxchg_32.h
+++ b/arch/x86/include/asm/cmpxchg_32.h
@@ -103,7 +103,6 @@ static inline bool __try_cmpxchg64(volat

#endif

-#define system_has_cmpxchg_double() boot_cpu_has(X86_FEATURE_CX8)
#define system_has_cmpxchg64() boot_cpu_has(X86_FEATURE_CX8)

#endif /* _ASM_X86_CMPXCHG_32_H */
--- a/arch/x86/include/asm/cmpxchg_64.h
+++ b/arch/x86/include/asm/cmpxchg_64.h
@@ -81,7 +81,6 @@ static __always_inline bool arch_try_cmp
return __arch_try_cmpxchg128(ptr, oldp, new,);
}

-#define system_has_cmpxchg_double() boot_cpu_has(X86_FEATURE_CX16)
#define system_has_cmpxchg128() boot_cpu_has(X86_FEATURE_CX16)

#endif /* _ASM_X86_CMPXCHG_64_H */
--- a/arch/x86/include/asm/percpu.h
+++ b/arch/x86/include/asm/percpu.h
@@ -349,23 +349,6 @@ do { \
#define this_cpu_cmpxchg_2(pcp, oval, nval) percpu_cmpxchg_op(2, volatile, pcp, oval, nval)
#define this_cpu_cmpxchg_4(pcp, oval, nval) percpu_cmpxchg_op(4, volatile, pcp, oval, nval)

-#ifdef CONFIG_X86_CMPXCHG64
-#define percpu_cmpxchg8b_double(pcp1, pcp2, o1, o2, n1, n2) \
-({ \
- bool __ret; \
- typeof(pcp1) __o1 = (o1), __n1 = (n1); \
- typeof(pcp2) __o2 = (o2), __n2 = (n2); \
- asm volatile("cmpxchg8b "__percpu_arg(1) \
- CC_SET(z) \
- : CC_OUT(z) (__ret), "+m" (pcp1), "+m" (pcp2), "+a" (__o1), "+d" (__o2) \
- : "b" (__n1), "c" (__n2)); \
- __ret; \
-})
-
-#define raw_cpu_cmpxchg_double_4 percpu_cmpxchg8b_double
-#define this_cpu_cmpxchg_double_4 percpu_cmpxchg8b_double
-#endif /* CONFIG_X86_CMPXCHG64 */
-
/*
* Per cpu atomic 64 bit operations are only available under 64 bit.
* 32 bit must fall back to generic operations.
@@ -388,30 +371,6 @@ do { \
#define this_cpu_add_return_8(pcp, val) percpu_add_return_op(8, volatile, pcp, val)
#define this_cpu_xchg_8(pcp, nval) percpu_xchg_op(8, volatile, pcp, nval)
#define this_cpu_cmpxchg_8(pcp, oval, nval) percpu_cmpxchg_op(8, volatile, pcp, oval, nval)
-
-/*
- * Pretty complex macro to generate cmpxchg16 instruction. The instruction
- * is not supported on early AMD64 processors so we must be able to emulate
- * it in software. The address used in the cmpxchg16 instruction must be
- * aligned to a 16 byte boundary.
- */
-#define percpu_cmpxchg16b_double(pcp1, pcp2, o1, o2, n1, n2) \
-({ \
- bool __ret; \
- typeof(pcp1) __o1 = (o1), __n1 = (n1); \
- typeof(pcp2) __o2 = (o2), __n2 = (n2); \
- alternative_io("leaq %P1,%%rsi\n\tcall this_cpu_cmpxchg16b_emu\n\t", \
- "cmpxchg16b " __percpu_arg(1) "\n\tsetz %0\n\t", \
- X86_FEATURE_CX16, \
- ASM_OUTPUT2("=a" (__ret), "+m" (pcp1), \
- "+m" (pcp2), "+d" (__o2)), \
- "b" (__n1), "c" (__n2), "a" (__o1) : "rsi"); \
- __ret; \
-})
-
-#define raw_cpu_cmpxchg_double_8 percpu_cmpxchg16b_double
-#define this_cpu_cmpxchg_double_8 percpu_cmpxchg16b_double
-
#endif

static __always_inline bool x86_this_cpu_constant_test_bit(unsigned int nr,
--- a/include/asm-generic/percpu.h
+++ b/include/asm-generic/percpu.h
@@ -99,19 +99,6 @@ do { \
__ret; \
})

-#define raw_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2) \
-({ \
- typeof(pcp1) *__p1 = raw_cpu_ptr(&(pcp1)); \
- typeof(pcp2) *__p2 = raw_cpu_ptr(&(pcp2)); \
- int __ret = 0; \
- if (*__p1 == (oval1) && *__p2 == (oval2)) { \
- *__p1 = nval1; \
- *__p2 = nval2; \
- __ret = 1; \
- } \
- (__ret); \
-})
-
#define __this_cpu_generic_read_nopreempt(pcp) \
({ \
typeof(pcp) ___ret; \
@@ -180,17 +167,6 @@ do { \
__ret; \
})

-#define this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2) \
-({ \
- int __ret; \
- unsigned long __flags; \
- raw_local_irq_save(__flags); \
- __ret = raw_cpu_generic_cmpxchg_double(pcp1, pcp2, \
- oval1, oval2, nval1, nval2); \
- raw_local_irq_restore(__flags); \
- __ret; \
-})
-
#ifndef raw_cpu_read_1
#define raw_cpu_read_1(pcp) raw_cpu_generic_read(pcp)
#endif
@@ -307,23 +283,6 @@ do { \
raw_cpu_generic_cmpxchg(pcp, oval, nval)
#endif

-#ifndef raw_cpu_cmpxchg_double_1
-#define raw_cpu_cmpxchg_double_1(pcp1, pcp2, oval1, oval2, nval1, nval2) \
- raw_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
-#endif
-#ifndef raw_cpu_cmpxchg_double_2
-#define raw_cpu_cmpxchg_double_2(pcp1, pcp2, oval1, oval2, nval1, nval2) \
- raw_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
-#endif
-#ifndef raw_cpu_cmpxchg_double_4
-#define raw_cpu_cmpxchg_double_4(pcp1, pcp2, oval1, oval2, nval1, nval2) \
- raw_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
-#endif
-#ifndef raw_cpu_cmpxchg_double_8
-#define raw_cpu_cmpxchg_double_8(pcp1, pcp2, oval1, oval2, nval1, nval2) \
- raw_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
-#endif
-
#ifndef this_cpu_read_1
#define this_cpu_read_1(pcp) this_cpu_generic_read(pcp)
#endif
@@ -440,21 +399,4 @@ do { \
this_cpu_generic_cmpxchg(pcp, oval, nval)
#endif

-#ifndef this_cpu_cmpxchg_double_1
-#define this_cpu_cmpxchg_double_1(pcp1, pcp2, oval1, oval2, nval1, nval2) \
- this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
-#endif
-#ifndef this_cpu_cmpxchg_double_2
-#define this_cpu_cmpxchg_double_2(pcp1, pcp2, oval1, oval2, nval1, nval2) \
- this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
-#endif
-#ifndef this_cpu_cmpxchg_double_4
-#define this_cpu_cmpxchg_double_4(pcp1, pcp2, oval1, oval2, nval1, nval2) \
- this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
-#endif
-#ifndef this_cpu_cmpxchg_double_8
-#define this_cpu_cmpxchg_double_8(pcp1, pcp2, oval1, oval2, nval1, nval2) \
- this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
-#endif
-
#endif /* _ASM_GENERIC_PERCPU_H_ */
--- a/include/linux/atomic/atomic-instrumented.h
+++ b/include/linux/atomic/atomic-instrumented.h
@@ -2234,21 +2234,6 @@ atomic_long_dec_if_positive(atomic_long_
arch_try_cmpxchg128_local(__ai_ptr, __ai_oldp, __VA_ARGS__); \
})

-#define cmpxchg_double(ptr, ...) \
-({ \
- typeof(ptr) __ai_ptr = (ptr); \
- kcsan_mb(); \
- instrument_atomic_read_write(__ai_ptr, 2 * sizeof(*__ai_ptr)); \
- arch_cmpxchg_double(__ai_ptr, __VA_ARGS__); \
-})
-
-
-#define cmpxchg_double_local(ptr, ...) \
-({ \
- typeof(ptr) __ai_ptr = (ptr); \
- instrument_atomic_read_write(__ai_ptr, 2 * sizeof(*__ai_ptr)); \
- arch_cmpxchg_double_local(__ai_ptr, __VA_ARGS__); \
-})

#endif /* _LINUX_ATOMIC_INSTRUMENTED_H */
-// 82d1be694fab30414527d0877c29fa75ed5a0b74
+// 3611991b015450e119bcd7417a9431af7f3ba13c
--- a/include/linux/percpu-defs.h
+++ b/include/linux/percpu-defs.h
@@ -343,33 +343,6 @@ static __always_inline void __this_cpu_p
pscr2_ret__; \
})

-/*
- * Special handling for cmpxchg_double. cmpxchg_double is passed two
- * percpu variables. The first has to be aligned to a double word
- * boundary and the second has to follow directly thereafter.
- * We enforce this on all architectures even if they don't support
- * a double cmpxchg instruction, since it's a cheap requirement, and it
- * avoids breaking the requirement for architectures with the instruction.
- */
-#define __pcpu_double_call_return_bool(stem, pcp1, pcp2, ...) \
-({ \
- bool pdcrb_ret__; \
- __verify_pcpu_ptr(&(pcp1)); \
- BUILD_BUG_ON(sizeof(pcp1) != sizeof(pcp2)); \
- VM_BUG_ON((unsigned long)(&(pcp1)) % (2 * sizeof(pcp1))); \
- VM_BUG_ON((unsigned long)(&(pcp2)) != \
- (unsigned long)(&(pcp1)) + sizeof(pcp1)); \
- switch(sizeof(pcp1)) { \
- case 1: pdcrb_ret__ = stem##1(pcp1, pcp2, __VA_ARGS__); break; \
- case 2: pdcrb_ret__ = stem##2(pcp1, pcp2, __VA_ARGS__); break; \
- case 4: pdcrb_ret__ = stem##4(pcp1, pcp2, __VA_ARGS__); break; \
- case 8: pdcrb_ret__ = stem##8(pcp1, pcp2, __VA_ARGS__); break; \
- default: \
- __bad_size_call_parameter(); break; \
- } \
- pdcrb_ret__; \
-})
-
#define __pcpu_size_call(stem, variable, ...) \
do { \
__verify_pcpu_ptr(&(variable)); \
@@ -426,9 +399,6 @@ do { \
#define raw_cpu_xchg(pcp, nval) __pcpu_size_call_return2(raw_cpu_xchg_, pcp, nval)
#define raw_cpu_cmpxchg(pcp, oval, nval) \
__pcpu_size_call_return2(raw_cpu_cmpxchg_, pcp, oval, nval)
-#define raw_cpu_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2) \
- __pcpu_double_call_return_bool(raw_cpu_cmpxchg_double_, pcp1, pcp2, oval1, oval2, nval1, nval2)
-
#define raw_cpu_sub(pcp, val) raw_cpu_add(pcp, -(val))
#define raw_cpu_inc(pcp) raw_cpu_add(pcp, 1)
#define raw_cpu_dec(pcp) raw_cpu_sub(pcp, 1)
@@ -488,11 +458,6 @@ do { \
raw_cpu_cmpxchg(pcp, oval, nval); \
})

-#define __this_cpu_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2) \
-({ __this_cpu_preempt_check("cmpxchg_double"); \
- raw_cpu_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2); \
-})
-
#define __this_cpu_sub(pcp, val) __this_cpu_add(pcp, -(typeof(pcp))(val))
#define __this_cpu_inc(pcp) __this_cpu_add(pcp, 1)
#define __this_cpu_dec(pcp) __this_cpu_sub(pcp, 1)
@@ -513,9 +478,6 @@ do { \
#define this_cpu_xchg(pcp, nval) __pcpu_size_call_return2(this_cpu_xchg_, pcp, nval)
#define this_cpu_cmpxchg(pcp, oval, nval) \
__pcpu_size_call_return2(this_cpu_cmpxchg_, pcp, oval, nval)
-#define this_cpu_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2) \
- __pcpu_double_call_return_bool(this_cpu_cmpxchg_double_, pcp1, pcp2, oval1, oval2, nval1, nval2)
-
#define this_cpu_sub(pcp, val) this_cpu_add(pcp, -(typeof(pcp))(val))
#define this_cpu_inc(pcp) this_cpu_add(pcp, 1)
#define this_cpu_dec(pcp) this_cpu_sub(pcp, 1)
--- a/scripts/atomic/gen-atomic-instrumented.sh
+++ b/scripts/atomic/gen-atomic-instrumented.sh
@@ -84,7 +84,6 @@ gen_xchg()
{
local xchg="$1"; shift
local order="$1"; shift
- local mult="$1"; shift

kcsan_barrier=""
if [ "${xchg%_local}" = "${xchg}" ]; then
@@ -104,8 +103,8 @@ cat <<EOF
EOF
[ -n "$kcsan_barrier" ] && printf "\t${kcsan_barrier}; \\\\\n"
cat <<EOF
- instrument_atomic_read_write(__ai_ptr, ${mult}sizeof(*__ai_ptr)); \\
- instrument_read_write(__ai_oldp, ${mult}sizeof(*__ai_oldp)); \\
+ instrument_atomic_read_write(__ai_ptr, sizeof(*__ai_ptr)); \\
+ instrument_read_write(__ai_oldp, sizeof(*__ai_oldp)); \\
arch_${xchg}${order}(__ai_ptr, __ai_oldp, __VA_ARGS__); \\
})
EOF
@@ -168,22 +167,16 @@ done

for xchg in "xchg" "cmpxchg" "cmpxchg64" "cmpxchg128" "try_cmpxchg" "try_cmpxchg64" "try_cmpxchg128"; do
for order in "" "_acquire" "_release" "_relaxed"; do
- gen_xchg "${xchg}" "${order}" ""
+ gen_xchg "${xchg}" "${order}"
printf "\n"
done
done

for xchg in "cmpxchg_local" "cmpxchg64_local" "cmpxchg128_local" "sync_cmpxchg" "try_cmpxchg_local" "try_cmpxchg64_local" "try_cmpxchg128_local"; do
- gen_xchg "${xchg}" "" ""
+ gen_xchg "${xchg}" ""
printf "\n"
done

-gen_xchg "cmpxchg_double" "" "2 * "
-
-printf "\n\n"
-
-gen_xchg "cmpxchg_double_local" "" "2 * "
-
cat <<EOF

#endif /* _LINUX_ATOMIC_INSTRUMENTED_H */




2023-05-15 08:59:36

by Heiko Carstens

[permalink] [raw]
Subject: Re: [PATCH v3 10/11] arch: Remove cmpxchg_double

On Mon, May 15, 2023 at 09:57:09AM +0200, Peter Zijlstra wrote:
> No moar users, remove the monster.
>
> Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
> ---
...
> arch/s390/include/asm/cmpxchg.h | 34 -----------------
> arch/s390/include/asm/percpu.h | 18 ---------

FWIW, for s390:
Acked-by: Heiko Carstens <[email protected]>