#ifndef _X86_IRQFLAGS_H_ #define _X86_IRQFLAGS_H_ #include #ifndef __ASSEMBLY__ /* * Interrupt control: */ static inline unsigned long native_save_fl(void) { unsigned long flags; /* * "=rm" is safe here, because "pop" adjusts the stack before * it evaluates its effective address -- this is part of the * documented behavior of the "pop" instruction. */ asm volatile("# __raw_save_flags\n\t" "pushf ; pop %0" : "=rm" (flags) : /* no input */ : "memory"); return flags; } static inline void native_restore_fl(unsigned long flags) { asm volatile("push %0 ; popf" : /* no output */ :"g" (flags) :"memory", "cc"); } static inline void native_irq_disable(void) { asm volatile("cli": : :"memory"); } static inline void native_irq_enable(void) { asm volatile("sti": : :"memory"); } static inline void native_safe_halt(void) { asm volatile("sti; hlt": : :"memory"); } static inline void native_halt(void) { asm volatile("hlt": : :"memory"); } #endif #ifdef CONFIG_X86_64 /* * Only returns from a trap or exception to a NMI context (intra-privilege * level near return) to the same SS and CS segments. Should be used * upon trap or exception return when nested over a NMI context so no iret is * issued. It takes care of modifying the eflags, rsp and returning to the * previous function. * * The stack, at that point, looks like : * * 0(rsp) RIP * 8(rsp) CS * 16(rsp) EFLAGS * 24(rsp) RSP * 32(rsp) SS * * Upon execution : * Copy EIP to the top of the return stack * Update top of return stack address * Pop eflags into the eflags register * Make the return stack current * Near return (popping the return address from the return stack) */ #define NATIVE_INTERRUPT_RETURN_NMI_SAFE pushq %rax; \ movq %rsp, %rax; \ movq 24+8(%rax), %rsp; \ pushq 0+8(%rax); \ pushq 16+8(%rax); \ movq (%rax), %rax; \ popfq; \ ret #else /* * Protected mode only, no V8086. Implies that protected mode must * be entered before NMIs or MCEs are enabled. Only returns from a trap or * exception to a NMI context (intra-privilege level far return). Should be used * upon trap or exception return when nested over a NMI context so no iret is * issued. * * The stack, at that point, looks like : * * 0(esp) EIP * 4(esp) CS * 8(esp) EFLAGS * * Upon execution : * Copy the stack eflags to top of stack * Pop eflags into the eflags register * Far return: pop EIP and CS into their register, and additionally pop EFLAGS. */ #define NATIVE_INTERRUPT_RETURN_NMI_SAFE pushl 8(%esp); \ popfl; \ lret $4 #endif #ifdef CONFIG_PARAVIRT #include #else #ifndef __ASSEMBLY__ static inline unsigned long arch_local_save_flags(void) { return native_save_fl(); } static inline void arch_local_irq_restore(unsigned long flags) { native_restore_fl(flags); } static inline void arch_local_irq_disable(void) { native_irq_disable(); } static inline void arch_local_irq_enable(void) { native_irq_enable(); } /* * Used in the idle loop; sti takes one instruction cycle * to complete: */ static inline void arch_safe_halt(void) { native_safe_halt(); } /* * Used when interrupts are already enabled or to * shutdown the processor: */ static inline void halt(void) { native_halt(); } /* * For spinlocks, etc: */ static inline unsigned long arch_local_irq_save(void) { unsigned long flags = arch_local_save_flags(); arch_local_irq_disable(); return flags; } #else #define ENABLE_INTERRUPTS(x) sti #define DISABLE_INTERRUPTS(x) cli #define INTERRUPT_RETURN_NMI_SAFE NATIVE_INTERRUPT_RETURN_NMI_SAFE #ifdef CONFIG_X86_64 #define SWAPGS swapgs /* * Currently paravirt can't handle swapgs nicely when we * don't have a stack we can rely on (such as a user space * stack). So we either find a way around these or just fault * and emulate if a guest tries to call swapgs directly. * * Either way, this is a good way to document that we don't * have a reliable stack. x86_64 only. */ #define SWAPGS_UNSAFE_STACK swapgs #define PARAVIRT_ADJUST_EXCEPTION_FRAME /* */ #define INTERRUPT_RETURN iretq #define USERGS_SYSRET64 \ swapgs; \ sysretq; #define USERGS_SYSRET32 \ swapgs; \ sysretl #define ENABLE_INTERRUPTS_SYSEXIT32 \ swapgs; \ sti; \ sysexit #else #define INTERRUPT_RETURN iret #define ENABLE_INTERRUPTS_SYSEXIT sti; sysexit #define GET_CR0_INTO_EAX movl %cr0, %eax #endif #endif /* __ASSEMBLY__ */ #endif /* CONFIG_PARAVIRT */ #ifndef __ASSEMBLY__ static inline int arch_irqs_disabled_flags(unsigned long flags) { return !(flags & X86_EFLAGS_IF); } static inline int arch_irqs_disabled(void) { unsigned long flags = arch_local_save_flags(); return arch_irqs_disabled_flags(flags); } #else #ifdef CONFIG_X86_64 #define ARCH_LOCKDEP_SYS_EXIT call lockdep_sys_exit_thunk #define ARCH_LOCKDEP_SYS_EXIT_IRQ \ TRACE_IRQS_ON; \ sti; \ SAVE_REST; \ LOCKDEP_SYS_EXIT; \ RESTORE_REST; \ cli; \ TRACE_IRQS_OFF; #else #define ARCH_LOCKDEP_SYS_EXIT \ pushl %eax; \ pushl %ecx; \ pushl %edx; \ call lockdep_sys_exit; \ popl %edx; \ popl %ecx; \ popl %eax; #define ARCH_LOCKDEP_SYS_EXIT_IRQ #endif #ifdef CONFIG_TRACE_IRQFLAGS # define TRACE_IRQS_ON call trace_hardirqs_on_thunk; # define TRACE_IRQS_OFF call trace_hardirqs_off_thunk; #else # define TRACE_IRQS_ON # define TRACE_IRQS_OFF #endif #ifdef CONFIG_DEBUG_LOCK_ALLOC # define LOCKDEP_SYS_EXIT ARCH_LOCKDEP_SYS_EXIT # define LOCKDEP_SYS_EXIT_IRQ ARCH_LOCKDEP_SYS_EXIT_IRQ # else # define LOCKDEP_SYS_EXIT # define LOCKDEP_SYS_EXIT_IRQ # endif #endif /* __ASSEMBLY__ */ #endif