/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2013 ARM Ltd.
*/
#ifndef __ASM_PERCPU_H
#define __ASM_PERCPU_H
#include <linux/preempt.h>
#include <asm/alternative.h>
#include <asm/cmpxchg.h>
#include <asm/stack_pointer.h>
#include <asm/sysreg.h>
static inline void set_my_cpu_offset(unsigned long off)
{
asm volatile(ALTERNATIVE("msr tpidr_el1, %0",
"msr tpidr_el2, %0",
ARM64_HAS_VIRT_HOST_EXTN)
:: "r" (off) : "memory");
}
static inline unsigned long __hyp_my_cpu_offset(void)
{
/*
* Non-VHE hyp code runs with preemption disabled. No need to hazard
* the register access against barrier() as in __kern_my_cpu_offset.
*/
return read_sysreg(tpidr_el2);
}
static inline unsigned long __kern_my_cpu_offset(void)
{
unsigned long off;
/*
* We want to allow caching the value, so avoid using volatile and
* instead use a fake stack read to hazard against barrier().
*/
asm(ALTERNATIVE("mrs %0, tpidr_el1",
"mrs %0, tpidr_el2",
ARM64_HAS_VIRT_HOST_EXTN)
: "=r" (off) :
"Q" (*(const unsigned long *)current_stack_pointer));
return off;
}
#ifdef __KVM_NVHE_HYPERVISOR__
#define __my_cpu_offset __hyp_my_cpu_offset()
#else
#define __my_cpu_offset __kern_my_cpu_offset()
#endif
#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); \
}
#define __PERCPU_OP_CASE(w, sfx, name, sz, op_llsc, op_lse) \
static inline void \
__percpu_##name##_case_##sz(void *ptr, unsigned long val) \
{ \
unsigned int loop; \
u##sz tmp; \
\
asm volatile (ARM64_LSE_ATOMIC_INSN( \
/* LL/SC */ \
"1: ldxr" #sfx "\t%" #w "[tmp], %[ptr]\n" \
#op_llsc "\t%" #w "[tmp], %" #w "[tmp], %" #w "[val]\n" \
" stxr" #sfx "\t%w[loop], %" #w "[tmp], %[ptr]\n" \
" cbnz %w[loop], 1b", \
/* LSE atomics */ \
#op_lse "\t%" #w "[val], %[ptr]\n" \
__nops(3)) \
: [loop] "=&r" (loop), [tmp] "=&r" (tmp), \
[ptr] "+Q"(*(u##sz *)ptr) \
: [val] "r" ((u##sz)(val))); \
}
#define __PERCPU_RET_OP_CASE(w, sfx, name, sz, op_llsc, op_lse) \
static inline u##sz \
__percpu_##name##_return_case_##sz(void *ptr, unsigned long val) \
{ \
unsigned int loop; \
u##sz ret; \
\
asm volatile (ARM64_LSE_ATOMIC_INSN( \
/* LL/SC */ \
"1: ldxr" #sfx "\t%" #w "[ret], %[ptr]\n" \
#op_llsc "\t%" #w "[ret], %" #w "[ret], %" #w "[val]\n" \
" stxr" #sfx "\t%w[loop], %" #w "[ret], %[ptr]\n" \
" cbnz %w[loop], 1b", \
/* LSE atomics */ \
#op_lse "\t%" #w "[val], %" #w "[ret], %[ptr]\n" \
#op_llsc "\t%" #w "[ret], %" #w "[ret], %" #w "[val]\n" \
__nops(2)) \
: [loop] "=&r" (loop), [ret] "=&r" (ret), \
[ptr] "+Q"(*(u##sz *)ptr) \
: [val] "r" ((u##sz)(val))); \
\
return ret; \
}
#define PERCPU_OP(name, op_llsc, op_lse) \
__PERCPU_OP_CASE(w, b, name, 8, op_llsc, op_lse) \
__PERCPU_OP_CASE(w, h, name, 16, op_llsc, op_lse) \
__PERCPU_OP_CASE(w, , name, 32, op_llsc, op_lse) \
__PERCPU_OP_CASE( , , name, 64, op_llsc, op_lse)
#define PERCPU_RET_OP(name, op_llsc, op_lse) \
__PERCPU_RET_OP_CASE(w, b, name, 8, op_llsc, op_lse) \
__PERCPU_RET_OP_CASE(w, h, name, 16, op_llsc, op_lse) \
__PERCPU_RET_OP_CASE(w, , name, 32, op_llsc, op_lse) \
__PERCPU_RET_OP_CASE( , , name, 64, op_llsc, op_lse)
PERCPU_RW_OPS(8)
PERCPU_RW_OPS(16)
PERCPU_RW_OPS(32)
PERCPU_RW_OPS(64)
PERCPU_OP(add, add, stadd)
PERCPU_OP(andnot, bic, stclr)
PERCPU_OP(or, orr, stset)
PERCPU_RET_OP(add, add, ldadd)
#undef PERCPU_RW_OPS
#undef __PERCPU_OP_CASE
#undef __PERCPU_RET_OP_CASE
#undef PERCPU_OP
#undef PERCPU_RET_OP
/*
* It would be nice to avoid the conditional call into the scheduler when
* re-enabling preemption for preemptible kernels, but doing that in a way
* which builds inside a module would mean messing directly with the preempt
* count. If you do this, peterz and tglx will hunt you down.
*
* Not to mention it'll break the actual preemption model for missing a
* preemption point when TIF_NEED_RESCHED gets set while preemption is
* disabled.
*/
#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 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)
#define this_cpu_read_8(pcp) \
_pcp_protect_return(__percpu_read_64, pcp)
#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)
#define this_cpu_write_8(pcp, val) \
_pcp_protect(__percpu_write_64, pcp, (unsigned long)val)
#define this_cpu_add_1(pcp, val) \
_pcp_protect(__percpu_add_case_8, pcp, val)
#define this_cpu_add_2(pcp, val) \
_pcp_protect(__percpu_add_case_16, pcp, val)
#define this_cpu_add_4(pcp, val) \
_pcp_protect(__percpu_add_case_32, pcp, val)
#define this_cpu_add_8(pcp, val) \
_pcp_protect(__percpu_add_case_64, pcp, val)
#define this_cpu_add_return_1(pcp, val) \
_pcp_protect_return(__percpu_add_return_case_8, pcp, val)
#define this_cpu_add_return_2(pcp, val) \
_pcp_protect_return(__percpu_add_return_case_16, pcp, val)
#define this_cpu_add_return_4(pcp, val) \
_pcp_protect_return(__percpu_add_return_case_32, pcp, val)
#define this_cpu_add_return_8(pcp, val) \
_pcp_protect_return(__percpu_add_return_case_64, pcp, val)
#define this_cpu_and_1(pcp, val) \
_pcp_protect(__percpu_andnot_case_8, pcp, ~val)
#define this_cpu_and_2(pcp, val) \
_pcp_protect(__percpu_andnot_case_16, pcp, ~val)
#define this_cpu_and_4(pcp, val) \
_pcp_protect(__percpu_andnot_case_32, pcp, ~val)
#define this_cpu_and_8(pcp, val) \
_pcp_protect(__percpu_andnot_case_64, pcp, ~val)
#define this_cpu_or_1(pcp, val) \
_pcp_protect(__percpu_or_case_8, pcp, val)
#define this_cpu_or_2(pcp, val) \
_pcp_protect(__percpu_or_case_16, pcp, val)
#define this_cpu_or_4(pcp, val) \
_pcp_protect(__percpu_or_case_32, pcp, val)
#define this_cpu_or_8(pcp, val) \
_pcp_protect(__percpu_or_case_64, pcp, val)
#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)
#define this_cpu_xchg_8(pcp, val) \
_pcp_protect_return(xchg_relaxed, pcp, val)
#define this_cpu_cmpxchg_1(pcp, o, n) \
_pcp_protect_return(cmpxchg_relaxed, pcp, o, n)
#define this_cpu_cmpxchg_2(pcp, o, n) \
_pcp_protect_return(cmpxchg_relaxed, pcp, o, n)
#define this_cpu_cmpxchg_4(pcp, o, n) \
_pcp_protect_return(cmpxchg_relaxed, pcp, o, n)
#define this_cpu_cmpxchg_8(pcp, o, n) \
_pcp_protect_return(cmpxchg_relaxed, pcp, o, n)
#define this_cpu_cmpxchg64(pcp, o, n) this_cpu_cmpxchg_8(pcp, o, n)
#define this_cpu_cmpxchg128(pcp, o, n) \
({ \
typedef typeof(pcp) pcp_op_T__; \
u128 old__, new__, ret__; \
pcp_op_T__ *ptr__; \
old__ = o; \
new__ = n; \
preempt_disable_notrace(); \
ptr__ = raw_cpu_ptr(&(pcp)); \
ret__ = cmpxchg128_local((void *)ptr__, old__, new__); \
preempt_enable_notrace(); \
ret__; \
})
#ifdef __KVM_NVHE_HYPERVISOR__
extern unsigned long __hyp_per_cpu_offset(unsigned int cpu);
#define __per_cpu_offset
#define per_cpu_offset(cpu) __hyp_per_cpu_offset((cpu))
#endif
#include <asm-generic/percpu.h>
/* Redefine macros for nVHE hyp under DEBUG_PREEMPT to avoid its dependencies. */
#if defined(__KVM_NVHE_HYPERVISOR__) && defined(CONFIG_DEBUG_PREEMPT)
#undef this_cpu_ptr
#define this_cpu_ptr raw_cpu_ptr
#undef __this_cpu_read
#define __this_cpu_read raw_cpu_read
#undef __this_cpu_write
#define __this_cpu_write raw_cpu_write
#endif
#endif /* __ASM_PERCPU_H */