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 /* Provide __cpuidle; we can't safely include <linux/cpu.h> */
  10 #define __cpuidle __attribute__((__section__(".cpuidle.text")))
  11
  12 /*
  13  * Interrupt control:
  14  */
  15
  16 /* Declaration required for gcc < 4.9 to prevent -Werror=missing-prototypes */
  17 extern inline unsigned long native_save_fl(void);
  18 extern inline unsigned long native_save_fl(void)
  19 {
  20         unsigned long flags;
  21
  22         /*
  23          * "=rm" is safe here, because "pop" adjusts the stack before
  24          * it evaluates its effective address -- this is part of the
  25          * documented behavior of the "pop" instruction.
  26          */
  27         asm volatile("# __raw_save_flags\n\t"
  28                      "pushf ; pop %0"
  29                      : "=rm" (flags)
  30                      : /* no input */
  31                      : "memory");
  32
  33         return flags;
  34 }
  35
  36 extern inline void native_restore_fl(unsigned long flags);
  37 extern inline void native_restore_fl(unsigned long flags)
  38 {
  39         asm volatile("push %0 ; popf"
  40                      : /* no output */
  41                      :"g" (flags)
  42                      :"memory", "cc");
  43 }
  44
  45 static inline void native_irq_disable(void)
  46 {
  47         asm volatile("cli": : :"memory");
  48 }
  49
  50 static inline void native_irq_enable(void)
  51 {
  52         asm volatile("sti": : :"memory");
  53 }
  54
  55 static inline __cpuidle void native_safe_halt(void)
  56 {
  57         asm volatile("sti; hlt": : :"memory");
  58 }
  59
  60 static inline __cpuidle void native_halt(void)
  61 {
  62         asm volatile("hlt": : :"memory");
  63 }
  64
  65 #endif
  66
  67 #ifdef CONFIG_PARAVIRT
  68 #include <asm/paravirt.h>
  69 #else
  70 #ifndef __ASSEMBLY__
  71 #include <linux/types.h>
  72
  73 static inline notrace unsigned long arch_local_save_flags(void)
  74 {
  75         return native_save_fl();
  76 }
  77
  78 static inline notrace void arch_local_irq_restore(unsigned long flags)
  79 {
  80         native_restore_fl(flags);
  81 }
  82
  83 static inline notrace void arch_local_irq_disable(void)
  84 {
  85         native_irq_disable();
  86 }
  87
  88 static inline notrace void arch_local_irq_enable(void)
  89 {
  90         native_irq_enable();
  91 }
  92
  93 /*
  94  * Used in the idle loop; sti takes one instruction cycle
  95  * to complete:
  96  */
  97 static inline __cpuidle void arch_safe_halt(void)
  98 {
  99         native_safe_halt();
 100 }
 101
 102 /*
 103  * Used when interrupts are already enabled or to
 104  * shutdown the processor:
 105  */
 106 static inline __cpuidle void halt(void)
 107 {
 108         native_halt();
 109 }
 110
 111 /*
 112  * For spinlocks, etc:
 113  */
 114 static inline notrace unsigned long arch_local_irq_save(void)
 115 {
 116         unsigned long flags = arch_local_save_flags();
 117         arch_local_irq_disable();
 118         return flags;
 119 }
 120 #else
 121
 122 #define ENABLE_INTERRUPTS(x)    sti
 123 #define DISABLE_INTERRUPTS(x)   cli
 124
 125 #ifdef CONFIG_X86_64
 126 #define SWAPGS  swapgs
 127 /*
 128  * Currently paravirt can't handle swapgs nicely when we
 129  * don't have a stack we can rely on (such as a user space
 130  * stack).  So we either find a way around these or just fault
 131  * and emulate if a guest tries to call swapgs directly.
 132  *
 133  * Either way, this is a good way to document that we don't
 134  * have a reliable stack. x86_64 only.
 135  */
 136 #define SWAPGS_UNSAFE_STACK     swapgs
 137
 138 #define PARAVIRT_ADJUST_EXCEPTION_FRAME /*  */
 139
 140 #define INTERRUPT_RETURN        jmp native_iret
 141 #define USERGS_SYSRET64                         \
 142         swapgs;                                 \
 143         sysretq;
 144 #define USERGS_SYSRET32                         \
 145         swapgs;                                 \
 146         sysretl
 147
 148 #ifdef CONFIG_DEBUG_ENTRY
 149 #define SAVE_FLAGS(x)           pushfq; popq %rax
 150 #endif
 151 #else
 152 #define INTERRUPT_RETURN                iret
 153 #define ENABLE_INTERRUPTS_SYSEXIT       sti; sysexit
 154 #define GET_CR0_INTO_EAX                movl %cr0, %eax
 155 #endif
 156
 157
 158 #endif /* __ASSEMBLY__ */
 159 #endif /* CONFIG_PARAVIRT */
 160
 161 #ifndef __ASSEMBLY__
 162 static inline int arch_irqs_disabled_flags(unsigned long flags)
 163 {
 164         return !(flags & X86_EFLAGS_IF);
 165 }
 166
 167 static 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