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Diffstat (limited to 'arch/arm64/include/asm/percpu.h')
| -rw-r--r-- | arch/arm64/include/asm/percpu.h | 271 |
1 files changed, 271 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/percpu.h b/arch/arm64/include/asm/percpu.h new file mode 100644 index 000000000..9abcc8ef3 --- /dev/null +++ b/arch/arm64/include/asm/percpu.h @@ -0,0 +1,271 @@ +/* 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 */ |