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 */
  19 extern inline unsigned long native_save_fl(void);
  20 extern 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
  38 extern inline void native_restore_fl(unsigned long flags);
  39 extern 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
  47 static inline void native_irq_disable(void)
  48 {
  49         asm volatile("cli": : :"memory");
  50 }
  51
  52 static inline void native_irq_enable(void)
  53 {
  54         asm volatile("sti": : :"memory");
  55 }
  56
  57 static inline __cpuidle void native_safe_halt(void)
  58 {
  59         mds_idle_clear_cpu_buffers();
  60         asm volatile("sti; hlt": : :"memory");
  61 }
  62
  63 static 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
  72 #include <asm/paravirt.h>
  73 #else
  74 #ifndef __ASSEMBLY__
  75 #include <linux/types.h>
  76
  77 static inline notrace unsigned long arch_local_save_flags(void)
  78 {
  79         return native_save_fl();
  80 }
  81
  82 static inline notrace void arch_local_irq_restore(unsigned long flags)
  83 {
  84         native_restore_fl(flags);
  85 }
  86
  87 static inline notrace void arch_local_irq_disable(void)
  88 {
  89         native_irq_disable();
  90 }
  91
  92 static 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  */
 101 static 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  */
 110 static inline __cpuidle void halt(void)
 111 {
 112         native_halt();
 113 }
 114
 115 /*
 116  * For spinlocks, etc:
 117  */
 118 static 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 #define SWAPGS  swapgs
 131 /*
 132  * Currently paravirt can't handle swapgs nicely when we
 133  * don't have a stack we can rely on (such as a user space
 134  * stack).  So we either find a way around these or just fault
 135  * and emulate if a guest tries to call swapgs directly.
 136  *
 137  * Either way, this is a good way to document that we don't
 138  * have a reliable stack. x86_64 only.
 139  */
 140 #define SWAPGS_UNSAFE_STACK     swapgs
 141
 142 #define PARAVIRT_ADJUST_EXCEPTION_FRAME /*  */
 143
 144 #define INTERRUPT_RETURN        jmp native_iret
 145 #define USERGS_SYSRET64                         \
 146         swapgs;                                 \
 147         sysretq;
 148 #define USERGS_SYSRET32                         \
 149         swapgs;                                 \
 150         sysretl
 151
 152 #ifdef CONFIG_DEBUG_ENTRY
 153 #define SAVE_FLAGS(x)           pushfq; popq %rax
 154 #endif
 155 #else
 156 #define INTERRUPT_RETURN                iret
 157 #define ENABLE_INTERRUPTS_SYSEXIT       sti; sysexit
 158 #define GET_CR0_INTO_EAX                movl %cr0, %eax
 159 #endif
 160
 161
 162 #endif /* __ASSEMBLY__ */
 163 #endif /* CONFIG_PARAVIRT */
 164
 165 #ifndef __ASSEMBLY__
 166 static inline int arch_irqs_disabled_flags(unsigned long flags)
 167 {
 168         return !(flags & X86_EFLAGS_IF);
 169 }
 170
 171 static inline int arch_irqs_disabled(void)
 172 {
 173         unsigned long flags = arch_local_save_flags();
 174
 175         return arch_irqs_disabled_flags(flags);
 176 }
 177 #endif /* !__ASSEMBLY__ */
 178
 179 #ifdef __ASSEMBLY__
 180 #ifdef CONFIG_TRACE_IRQFLAGS
 181 #  define TRACE_IRQS_ON         call trace_hardirqs_on_thunk;
 182 #  define TRACE_IRQS_OFF        call trace_hardirqs_off_thunk;
 183 #else
 184 #  define TRACE_IRQS_ON
 185 #  define TRACE_IRQS_OFF
 186 #endif
 187 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 188 #  ifdef CONFIG_X86_64
 189 #    define LOCKDEP_SYS_EXIT            call lockdep_sys_exit_thunk
 190 #    define LOCKDEP_SYS_EXIT_IRQ \
 191         TRACE_IRQS_ON; \
 192         sti; \
 193         call lockdep_sys_exit_thunk; \
 194         cli; \
 195         TRACE_IRQS_OFF;
 196 #  else
 197 #    define LOCKDEP_SYS_EXIT \
 198         pushl %eax;                             \
 199         pushl %ecx;                             \
 200         pushl %edx;                             \
 201         call lockdep_sys_exit;                  \
 202         popl %edx;                              \
 203         popl %ecx;                              \
 204         popl %eax;
 205 #    define LOCKDEP_SYS_EXIT_IRQ
 206 #  endif
 207 #else
 208 #  define LOCKDEP_SYS_EXIT
 209 #  define LOCKDEP_SYS_EXIT_IRQ
 210 #endif
 211 #endif /* __ASSEMBLY__ */
 212
 213 #endif