LXR linux/arch/x86/include/asm/irqflags.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef _X86_IRQFLAGS_H_
   3#define _X86_IRQFLAGS_H_
   4
   5#include <asm/processor-flags.h>
   6
   7#ifndef __ASSEMBLY__
   8
   9#include <asm/nospec-branch.h>
  10
  11/* Provide __cpuidle; we can't safely include <linux/cpu.h> */
  12#define __cpuidle __attribute__((__section__(".cpuidle.text")))
  13
  14/*
  15 * Interrupt control:
  16 */
  17
  18/* Declaration required for gcc < 4.9 to prevent -Werror=missing-prototypes */
  19extern inline unsigned long native_save_fl(void);
  20extern inline unsigned long native_save_fl(void)
  21{
  22        unsigned long flags;
  23
  24        /*
  25         * "=rm" is safe here, because "pop" adjusts the stack before
  26         * it evaluates its effective address -- this is part of the
  27         * documented behavior of the "pop" instruction.
  28         */
  29        asm volatile("# __raw_save_flags\n\t"
  30                     "pushf ; pop %0"
  31                     : "=rm" (flags)
  32                     : /* no input */
  33                     : "memory");
  34
  35        return flags;
  36}
  37
  38extern inline void native_restore_fl(unsigned long flags);
  39extern inline void native_restore_fl(unsigned long flags)
  40{
  41        asm volatile("push %0 ; popf"
  42                     : /* no output */
  43                     :"g" (flags)
  44                     :"memory", "cc");
  45}
  46
  47static inline void native_irq_disable(void)
  48{
  49        asm volatile("cli": : :"memory");
  50}
  51
  52static inline void native_irq_enable(void)
  53{
  54        asm volatile("sti": : :"memory");
  55}
  56
  57static inline __cpuidle void native_safe_halt(void)
  58{
  59        mds_idle_clear_cpu_buffers();
  60        asm volatile("sti; hlt": : :"memory");
  61}
  62
  63static inline __cpuidle void native_halt(void)
  64{
  65        mds_idle_clear_cpu_buffers();
  66        asm volatile("hlt": : :"memory");
  67}
  68
  69#endif
  70
  71#ifdef CONFIG_PARAVIRT_XXL
  72#include <asm/paravirt.h>
  73#else
  74#ifndef __ASSEMBLY__
  75#include <linux/types.h>
  76
  77static inline notrace unsigned long arch_local_save_flags(void)
  78{
  79        return native_save_fl();
  80}
  81
  82static inline notrace void arch_local_irq_restore(unsigned long flags)
  83{
  84        native_restore_fl(flags);
  85}
  86
  87static inline notrace void arch_local_irq_disable(void)
  88{
  89        native_irq_disable();
  90}
  91
  92static inline notrace void arch_local_irq_enable(void)
  93{
  94        native_irq_enable();
  95}
  96
  97/*
  98 * Used in the idle loop; sti takes one instruction cycle
  99 * to complete:
 100 */
 101static inline __cpuidle void arch_safe_halt(void)
 102{
 103        native_safe_halt();
 104}
 105
 106/*
 107 * Used when interrupts are already enabled or to
 108 * shutdown the processor:
 109 */
 110static inline __cpuidle void halt(void)
 111{
 112        native_halt();
 113}
 114
 115/*
 116 * For spinlocks, etc:
 117 */
 118static inline notrace unsigned long arch_local_irq_save(void)
 119{
 120        unsigned long flags = arch_local_save_flags();
 121        arch_local_irq_disable();
 122        return flags;
 123}
 124#else
 125
 126#define ENABLE_INTERRUPTS(x)    sti
 127#define DISABLE_INTERRUPTS(x)   cli
 128
 129#ifdef CONFIG_X86_64
 130#ifdef CONFIG_DEBUG_ENTRY
 131#define SAVE_FLAGS(x)           pushfq; popq %rax
 132#endif
 133
 134#define SWAPGS  swapgs
 135/*
 136 * Currently paravirt can't handle swapgs nicely when we
 137 * don't have a stack we can rely on (such as a user space
 138 * stack).  So we either find a way around these or just fault
 139 * and emulate if a guest tries to call swapgs directly.
 140 *
 141 * Either way, this is a good way to document that we don't
 142 * have a reliable stack. x86_64 only.
 143 */
 144#define SWAPGS_UNSAFE_STACK     swapgs
 145
 146#define INTERRUPT_RETURN        jmp native_iret
 147#define USERGS_SYSRET64                         \
 148        swapgs;                                 \
 149        sysretq;
 150#define USERGS_SYSRET32                         \
 151        swapgs;                                 \
 152        sysretl
 153
 154#else
 155#define INTERRUPT_RETURN                iret
 156#endif
 157
 158#endif /* __ASSEMBLY__ */
 159#endif /* CONFIG_PARAVIRT_XXL */
 160
 161#ifndef __ASSEMBLY__
 162static inline int arch_irqs_disabled_flags(unsigned long flags)
 163{
 164        return !(flags & X86_EFLAGS_IF);
 165}
 166
 167static inline int arch_irqs_disabled(void)
 168{
 169        unsigned long flags = arch_local_save_flags();
 170
 171        return arch_irqs_disabled_flags(flags);
 172}
 173#endif /* !__ASSEMBLY__ */
 174
 175#ifdef __ASSEMBLY__
 176#ifdef CONFIG_TRACE_IRQFLAGS
 177#  define TRACE_IRQS_ON         call trace_hardirqs_on_thunk;
 178#  define TRACE_IRQS_OFF        call trace_hardirqs_off_thunk;
 179#else
 180#  define TRACE_IRQS_ON
 181#  define TRACE_IRQS_OFF
 182#endif
 183#ifdef CONFIG_DEBUG_LOCK_ALLOC
 184#  ifdef CONFIG_X86_64
 185#    define LOCKDEP_SYS_EXIT            call lockdep_sys_exit_thunk
 186#    define LOCKDEP_SYS_EXIT_IRQ \
 187        TRACE_IRQS_ON; \
 188        sti; \
 189        call lockdep_sys_exit_thunk; \
 190        cli; \
 191        TRACE_IRQS_OFF;
 192#  else
 193#    define LOCKDEP_SYS_EXIT \
 194        pushl %eax;                             \
 195        pushl %ecx;                             \
 196        pushl %edx;                             \
 197        call lockdep_sys_exit;                  \
 198        popl %edx;                              \
 199        popl %ecx;                              \
 200        popl %eax;
 201#    define LOCKDEP_SYS_EXIT_IRQ
 202#  endif
 203#else
 204#  define LOCKDEP_SYS_EXIT
 205#  define LOCKDEP_SYS_EXIT_IRQ
 206#endif
 207#endif /* __ASSEMBLY__ */
 208
 209#endif
 210