summaryrefslogtreecommitdiffstats
path: root/arch/arm64/include/asm/percpu.h
diff options
context:
space:
mode:
Diffstat (limited to 'arch/arm64/include/asm/percpu.h')
-rw-r--r--arch/arm64/include/asm/percpu.h261
1 files changed, 261 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..b9ba19dbd
--- /dev/null
+++ b/arch/arm64/include/asm/percpu.h
@@ -0,0 +1,261 @@
+/* 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.
+ */
+#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, ...) \
+({ \
+ 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)
+
+#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 */