| // Copyright 2016 The Fuchsia Authors |
| // |
| // Use of this source code is governed by a MIT-style |
| // license that can be found in the LICENSE file or at |
| // https://opensource.org/licenses/MIT |
| |
| #ifndef ZIRCON_KERNEL_ARCH_ARM64_INCLUDE_ARCH_CURRENT_THREAD_H_ |
| #define ZIRCON_KERNEL_ARCH_ARM64_INCLUDE_ARCH_CURRENT_THREAD_H_ |
| |
| #include <lib/arch/intrin.h> |
| |
| /* use the cpu local thread context pointer to store current_thread */ |
| static inline Thread* arch_get_current_thread(void) { |
| #ifdef __clang__ |
| // Clang with --target=aarch64-fuchsia -mtp=el1 reads |
| // TPIDR_EL1 for __builtin_thread_pointer (instead of the usual |
| // TPIDR_EL0 for user mode). Using the intrinsic instead of asm |
| // lets the compiler understand what it's doing a little better, |
| // which conceivably could let it optimize better. |
| char* tp = (char*)__builtin_thread_pointer(); |
| #else |
| char* tp = (char*)__arm_rsr64("tpidr_el1"); |
| #endif |
| tp -= offsetof(Thread, arch_.thread_pointer_location); |
| return (Thread*)tp; |
| } |
| |
| static inline void arch_set_current_thread(Thread* t) { |
| __arm_wsr64("tpidr_el1", (uint64_t)&t->arch_.thread_pointer_location); |
| __isb(ARM_MB_SY); |
| } |
| |
| #endif // ZIRCON_KERNEL_ARCH_ARM64_INCLUDE_ARCH_CURRENT_THREAD_H_ |
