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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __ARCH_S390_PERCPU__
#define __ARCH_S390_PERCPU__
#include <linux/preempt.h>
#include <asm/cmpxchg.h>
#include <asm/march.h>
/*
* s390 uses its own implementation for per cpu data, the offset of
* the cpu local data area is cached in the cpu's lowcore memory.
*/
#define __my_cpu_offset get_lowcore()->percpu_offset
#define arch_raw_cpu_ptr(_ptr) \
({ \
unsigned long lc_percpu, tcp_ptr__; \
\
tcp_ptr__ = (__force unsigned long)(_ptr); \
lc_percpu = offsetof(struct lowcore, percpu_offset); \
asm_inline volatile( \
ALTERNATIVE("ag %[__ptr__],%[offzero](%%r0)\n", \
"ag %[__ptr__],%[offalt](%%r0)\n", \
ALT_FEATURE(MFEATURE_LOWCORE)) \
: [__ptr__] "+d" (tcp_ptr__) \
: [offzero] "i" (lc_percpu), \
[offalt] "i" (lc_percpu + LOWCORE_ALT_ADDRESS), \
"m" (((struct lowcore *)0)->percpu_offset) \
: "cc"); \
(TYPEOF_UNQUAL(*(_ptr)) __force __kernel *)tcp_ptr__; \
})
/*
* We use a compare-and-swap loop since that uses less cpu cycles than
* disabling and enabling interrupts like the generic variant would do.
*/
#define arch_this_cpu_to_op_simple(pcp, val, op) \
({ \
typedef typeof(pcp) pcp_op_T__; \
pcp_op_T__ old__, new__, prev__; \
pcp_op_T__ *ptr__; \
preempt_disable_notrace(); \
ptr__ = raw_cpu_ptr(&(pcp)); \
prev__ = READ_ONCE(*ptr__); \
do { \
old__ = prev__; \
new__ = old__ op (val); \
prev__ = cmpxchg(ptr__, old__, new__); \
} while (prev__ != old__); \
preempt_enable_notrace(); \
new__; \
})
#define this_cpu_add_1(pcp, val) arch_this_cpu_to_op_simple(pcp, val, +)
#define this_cpu_add_2(pcp, val) arch_this_cpu_to_op_simple(pcp, val, +)
#define this_cpu_add_return_1(pcp, val) arch_this_cpu_to_op_simple(pcp, val, +)
#define this_cpu_add_return_2(pcp, val) arch_this_cpu_to_op_simple(pcp, val, +)
#define this_cpu_and_1(pcp, val) arch_this_cpu_to_op_simple(pcp, val, &)
#define this_cpu_and_2(pcp, val) arch_this_cpu_to_op_simple(pcp, val, &)
#define this_cpu_or_1(pcp, val) arch_this_cpu_to_op_simple(pcp, val, |)
#define this_cpu_or_2(pcp, val) arch_this_cpu_to_op_simple(pcp, val, |)
/*
* Macros to be used for percpu code section based on atomic instructions.
*
* Avoid the need to use preempt_disable() / preempt_disable() pairs and the
* conditional preempt_schedule_notrace() function calls which come with
* this. The idea is that this_cpu operations based on atomic instructions are
* guarded with mviy instructions:
*
* - The first mviy instruction writes the register number, which contains the
* percpu address variable to lowcore. This also indicates that a percpu
* code section is executed.
*
* - The first mviy instruction following the mviy instruction must be the ag
* instruction which adds the percpu offset to the percpu address register.
*
* - Afterwards the atomic percpu operation follows.
*
* - Then a second mviy instruction writes a zero to lowcore, which indicates
* the end of the percpu code section.
*
* - In case of an interrupt/exception/nmi the register number which was
* written to lowcore is copied to the exception frame (pt_regs), and a zero
* is written to lowcore.
*
* - On return to the previous context it is checked if a percpu code section
* was executed (saved register number not zero), and if the process was
* migrated to a different cpu. If the percpu offset was already added to
* the percpu address register (instruction address does _not_ point to the
* ag instruction) the content of the percpu address register is adjusted so
* it points to percpu variable of the new cpu.
*
* Inline assemblies making use of this typically have a code sequence like:
*
* MVIY_PERCPU(...) <- start of percpu code section
* AG_ALT(...) <- add percpu offset; must be the second instruction
* atomic_op <- atomic op
* MVIY_ALT(...) <- end of percpu code section
*/
#define MVIY_PERCPU(disp, dispalt, reg) \
".macro GEN_MVIY disp reg\n" \
".irp rs,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15\n" \
" .ifc \\reg,%%r\\rs\n" \
" mviy \\disp(%%r0),\\rs\n" \
" .endif\n" \
".endr\n" \
".endm\n" \
ALTERNATIVE("GEN_MVIY " __stringify(disp) " " __stringify(reg) "\n", \
"GEN_MVIY " __stringify(dispalt) " " __stringify(reg) "\n", \
ALT_FEATURE(MFEATURE_LOWCORE)) \
".purgem GEN_MVIY\n"
#define MVIY_ALT(disp, dispalt) \
ALTERNATIVE(" mviy " disp "(%%r0),0\n", \
" mviy " dispalt "(%%r0),0\n", \
ALT_FEATURE(MFEATURE_LOWCORE))
#define AG_ALT(disp, dispalt, reg) \
ALTERNATIVE(" ag " reg ", " disp "(%%r0)\n", \
" ag " reg ", " dispalt "(%%r0)\n", \
ALT_FEATURE(MFEATURE_LOWCORE))
#ifndef MARCH_HAS_Z196_FEATURES
#define this_cpu_add_4(pcp, val) arch_this_cpu_to_op_simple(pcp, val, +)
#define this_cpu_add_8(pcp, val) arch_this_cpu_to_op_simple(pcp, val, +)
#define this_cpu_add_return_4(pcp, val) arch_this_cpu_to_op_simple(pcp, val, +)
#define this_cpu_add_return_8(pcp, val) arch_this_cpu_to_op_simple(pcp, val, +)
#define this_cpu_and_4(pcp, val) arch_this_cpu_to_op_simple(pcp, val, &)
#define this_cpu_and_8(pcp, val) arch_this_cpu_to_op_simple(pcp, val, &)
#define this_cpu_or_4(pcp, val) arch_this_cpu_to_op_simple(pcp, val, |)
#define this_cpu_or_8(pcp, val) arch_this_cpu_to_op_simple(pcp, val, |)
#else /* MARCH_HAS_Z196_FEATURES */
#define arch_this_cpu_add(pcp, val, op1, op2, szcast) \
do { \
unsigned long lc_pcpr, lc_pcpo; \
typedef typeof(pcp) pcp_op_T__; \
pcp_op_T__ val__ = (val); \
pcp_op_T__ old__, *ptr__; \
\
lc_pcpr = offsetof(struct lowcore, percpu_register); \
lc_pcpo = offsetof(struct lowcore, percpu_offset); \
ptr__ = PERCPU_PTR(&(pcp)); \
if (__builtin_constant_p(val__) && \
((szcast)val__ > -129) && ((szcast)val__ < 128)) { \
asm volatile( \
MVIY_PERCPU("%[disppcpr]", "%[dispaltpcpr]", "%[ptr__]")\
AG_ALT("%[disppcpo]", "%[dispaltpcpo]", "%[ptr__]") \
op2 " 0(%[ptr__]),%[val__]\n" \
MVIY_ALT("%[disppcpr]", "%[dispaltpcpr]") \
: [ptr__] "+&a" (ptr__), "+m" (*ptr__), \
"=m" (((struct lowcore *)0)->percpu_register) \
: [val__] "i" ((szcast)val__), \
[disppcpr] "i" (lc_pcpr), \
[disppcpo] "i" (lc_pcpo), \
[dispaltpcpr] "i" (lc_pcpr + LOWCORE_ALT_ADDRESS), \
[dispaltpcpo] "i" (lc_pcpo + LOWCORE_ALT_ADDRESS), \
"m" (((struct lowcore *)0)->percpu_offset) \
: "cc"); \
} else { \
asm volatile( \
MVIY_PERCPU("%[disppcpr]", "%[dispaltpcpr]", "%[ptr__]")\
AG_ALT("%[disppcpo]", "%[dispaltpcpo]", "%[ptr__]") \
op1 " %[old__],%[val__],0(%[ptr__])\n" \
MVIY_ALT("%[disppcpr]", "%[dispaltpcpr]") \
: [old__] "=&d" (old__), \
[ptr__] "+&a" (ptr__), "+m" (*ptr__), \
"=m" (((struct lowcore *)0)->percpu_register) \
: [val__] "d" (val__), \
[disppcpr] "i" (lc_pcpr), \
[disppcpo] "i" (lc_pcpo), \
[dispaltpcpr] "i" (lc_pcpr + LOWCORE_ALT_ADDRESS), \
[dispaltpcpo] "i" (lc_pcpo + LOWCORE_ALT_ADDRESS), \
"m" (((struct lowcore *)0)->percpu_offset) \
: "cc"); \
} \
} while (0)
#define this_cpu_add_4(pcp, val) arch_this_cpu_add(pcp, val, "laa", "asi", int)
#define this_cpu_add_8(pcp, val) arch_this_cpu_add(pcp, val, "laag", "agsi", long)
#define arch_this_cpu_add_return(pcp, val, op) \
({ \
unsigned long lc_pcpr, lc_pcpo; \
typedef typeof(pcp) pcp_op_T__; \
pcp_op_T__ val__ = (val); \
pcp_op_T__ old__, *ptr__; \
\
lc_pcpr = offsetof(struct lowcore, percpu_register); \
lc_pcpo = offsetof(struct lowcore, percpu_offset); \
ptr__ = PERCPU_PTR(&(pcp)); \
asm_inline volatile( \
MVIY_PERCPU("%[disppcpr]", "%[dispaltpcpr]", "%[ptr__]")\
AG_ALT("%[disppcpo]", "%[dispaltpcpo]", "%[ptr__]") \
op " %[old__],%[val__],0(%[ptr__])\n" \
MVIY_ALT("%[disppcpr]", "%[dispaltpcpr]") \
: [old__] "=&d" (old__), \
[ptr__] "+&a" (ptr__), "+m" (*ptr__), \
"=m" (((struct lowcore *)0)->percpu_register) \
: [val__] "d" (val__), \
[disppcpr] "i" (lc_pcpr), \
[disppcpo] "i" (lc_pcpo), \
[dispaltpcpr] "i" (lc_pcpr + LOWCORE_ALT_ADDRESS), \
[dispaltpcpo] "i" (lc_pcpo + LOWCORE_ALT_ADDRESS), \
"m" (((struct lowcore *)0)->percpu_offset) \
: "cc"); \
old__ + val__; \
})
#define this_cpu_add_return_4(pcp, val) arch_this_cpu_add_return(pcp, val, "laa")
#define this_cpu_add_return_8(pcp, val) arch_this_cpu_add_return(pcp, val, "laag")
#define arch_this_cpu_to_op(pcp, val, op) \
do { \
unsigned long lc_pcpr, lc_pcpo; \
typedef typeof(pcp) pcp_op_T__; \
pcp_op_T__ val__ = (val); \
pcp_op_T__ old__, *ptr__; \
\
lc_pcpr = offsetof(struct lowcore, percpu_register); \
lc_pcpo = offsetof(struct lowcore, percpu_offset); \
ptr__ = PERCPU_PTR(&(pcp)); \
asm_inline volatile( \
MVIY_PERCPU("%[disppcpr]", "%[dispaltpcpr]", "%[ptr__]")\
AG_ALT("%[disppcpo]", "%[dispaltpcpo]", "%[ptr__]") \
op " %[old__],%[val__],0(%[ptr__])\n" \
MVIY_ALT("%[disppcpr]", "%[dispaltpcpr]") \
: [old__] "=&d" (old__), \
[ptr__] "+&a" (ptr__), "+m" (*ptr__), \
"=m" (((struct lowcore *)0)->percpu_register) \
: [val__] "d" (val__), \
[disppcpr] "i" (lc_pcpr), \
[disppcpo] "i" (lc_pcpo), \
[dispaltpcpr] "i" (lc_pcpr + LOWCORE_ALT_ADDRESS), \
[dispaltpcpo] "i" (lc_pcpo + LOWCORE_ALT_ADDRESS), \
"m" (((struct lowcore *)0)->percpu_offset) \
: "cc"); \
} while (0)
#define this_cpu_and_4(pcp, val) arch_this_cpu_to_op(pcp, val, "lan")
#define this_cpu_and_8(pcp, val) arch_this_cpu_to_op(pcp, val, "lang")
#define this_cpu_or_4(pcp, val) arch_this_cpu_to_op(pcp, val, "lao")
#define this_cpu_or_8(pcp, val) arch_this_cpu_to_op(pcp, val, "laog")
#endif /* MARCH_HAS_Z196_FEATURES */
#define arch_this_cpu_read(pcp, op) \
({ \
unsigned long lc_pcpr, lc_pcpo, res__; \
typedef typeof(pcp) pcp_op_T__; \
pcp_op_T__ *ptr__; \
\
lc_pcpr = offsetof(struct lowcore, percpu_register); \
lc_pcpo = offsetof(struct lowcore, percpu_offset); \
ptr__ = PERCPU_PTR(&(pcp)); \
asm_inline volatile( \
MVIY_PERCPU("%[disppcpr]", "%[dispaltpcpr]", "%[ptr__]")\
AG_ALT("%[disppcpo]", "%[dispaltpcpo]", "%[ptr__]") \
op " %[res__],0(%[ptr__])\n" \
MVIY_ALT("%[disppcpr]", "%[dispaltpcpr]") \
: [res__] "=&d" (res__), [ptr__] "+&a" (ptr__), \
"=m" (((struct lowcore *)0)->percpu_register) \
: [disppcpr] "i" (lc_pcpr), \
[disppcpo] "i" (lc_pcpo), \
[dispaltpcpr] "i" (lc_pcpr + LOWCORE_ALT_ADDRESS), \
[dispaltpcpo] "i" (lc_pcpo + LOWCORE_ALT_ADDRESS), \
"m" (*ptr__), \
"m" (((struct lowcore *)0)->percpu_offset) \
: "cc"); \
(pcp_op_T__)res__; \
})
#define this_cpu_read_1(pcp) arch_this_cpu_read(pcp, "llgc")
#define this_cpu_read_2(pcp) arch_this_cpu_read(pcp, "llgh")
#define this_cpu_read_4(pcp) arch_this_cpu_read(pcp, "llgf")
#define this_cpu_read_8(pcp) arch_this_cpu_read(pcp, "lg")
#define arch_this_cpu_write(pcp, val, op) \
do { \
unsigned long lc_pcpr, lc_pcpo; \
typedef typeof(pcp) pcp_op_T__; \
pcp_op_T__ *ptr__, val__ = (val); \
\
lc_pcpr = offsetof(struct lowcore, percpu_register); \
lc_pcpo = offsetof(struct lowcore, percpu_offset); \
ptr__ = PERCPU_PTR(&(pcp)); \
asm_inline volatile( \
MVIY_PERCPU("%[disppcpr]", "%[dispaltpcpr]", "%[ptr__]")\
AG_ALT("%[disppcpo]", "%[dispaltpcpo]", "%[ptr__]") \
op " %[val__],0(%[ptr__])\n" \
MVIY_ALT("%[disppcpr]", "%[dispaltpcpr]") \
: [ptr__] "+&a" (ptr__), "=m" (*ptr__), \
"=m" (((struct lowcore *)0)->percpu_register) \
: [val__] "d" (val__), \
[disppcpr] "i" (lc_pcpr), \
[disppcpo] "i" (lc_pcpo), \
[dispaltpcpr] "i" (lc_pcpr + LOWCORE_ALT_ADDRESS), \
[dispaltpcpo] "i" (lc_pcpo + LOWCORE_ALT_ADDRESS), \
"m" (((struct lowcore *)0)->percpu_offset) \
: "cc"); \
} while (0)
#define this_cpu_write_1(pcp, val) arch_this_cpu_write(pcp, val, "stc")
#define this_cpu_write_2(pcp, val) arch_this_cpu_write(pcp, val, "sth")
#define this_cpu_write_4(pcp, val) arch_this_cpu_write(pcp, val, "st")
#define this_cpu_write_8(pcp, val) arch_this_cpu_write(pcp, val, "stg")
#define arch_this_cpu_cmpxchg(pcp, oval, nval) \
({ \
typedef typeof(pcp) pcp_op_T__; \
pcp_op_T__ ret__; \
pcp_op_T__ *ptr__; \
preempt_disable_notrace(); \
ptr__ = raw_cpu_ptr(&(pcp)); \
ret__ = cmpxchg(ptr__, oval, nval); \
preempt_enable_notrace(); \
ret__; \
})
#define this_cpu_cmpxchg_1(pcp, oval, nval) arch_this_cpu_cmpxchg(pcp, oval, nval)
#define this_cpu_cmpxchg_2(pcp, oval, nval) arch_this_cpu_cmpxchg(pcp, oval, nval)
#define this_cpu_cmpxchg_4(pcp, oval, nval) arch_this_cpu_cmpxchg(pcp, oval, nval)
#define this_cpu_cmpxchg_8(pcp, oval, nval) arch_this_cpu_cmpxchg(pcp, oval, nval)
#define this_cpu_cmpxchg64(pcp, o, n) this_cpu_cmpxchg_8(pcp, o, n)
#define this_cpu_cmpxchg128(pcp, oval, nval) \
({ \
typedef typeof(pcp) pcp_op_T__; \
u128 old__, new__, ret__; \
pcp_op_T__ *ptr__; \
old__ = oval; \
new__ = nval; \
preempt_disable_notrace(); \
ptr__ = raw_cpu_ptr(&(pcp)); \
ret__ = cmpxchg128((void *)ptr__, old__, new__); \
preempt_enable_notrace(); \
ret__; \
})
#define arch_this_cpu_xchg(pcp, nval) \
({ \
typeof(pcp) *ptr__; \
typeof(pcp) ret__; \
preempt_disable_notrace(); \
ptr__ = raw_cpu_ptr(&(pcp)); \
ret__ = xchg(ptr__, nval); \
preempt_enable_notrace(); \
ret__; \
})
#define this_cpu_xchg_1(pcp, nval) arch_this_cpu_xchg(pcp, nval)
#define this_cpu_xchg_2(pcp, nval) arch_this_cpu_xchg(pcp, nval)
#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)
#include <asm-generic/percpu.h>
#endif /* __ARCH_S390_PERCPU__ */
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