arch/x86/include/mach-xen/asm/irqflags.h

   1 #ifndef _X86_IRQFLAGS_H_
   2 #define _X86_IRQFLAGS_H_
   3
   4 #include <asm/smp-processor-id.h>
   5
   6 #ifndef __ASSEMBLY__
   7 #include <linux/types.h>
   8 #include <xen/interface/vcpu.h>
   9 /*
  10  * The use of 'barrier' in the following reflects their use as local-lock
  11  * operations. Reentrancy must be prevented (e.g., __cli()) /before/ following
  12  * critical operations are executed. All critical operations must complete
  13  * /before/ reentrancy is permitted (e.g., __sti()). Alpha architecture also
  14  * includes these barriers, for example.
  15  */
  16
  17 #define xen_save_fl(void) vcpu_info_read(evtchn_upcall_mask)
  18
  19 #define xen_restore_fl(f)                                       \
  20 do {                                                            \
  21         vcpu_info_t *_vcpu;                                     \
  22         barrier();                                              \
  23         _vcpu = current_vcpu_info();                            \
  24         if ((_vcpu->evtchn_upcall_mask = (f)) == 0) {           \
  25                 barrier(); /* unmask then check (avoid races) */\
  26                 if (unlikely(_vcpu->evtchn_upcall_pending))     \
  27                         force_evtchn_callback();                \
  28         }                                                       \
  29 } while (0)
  30
  31 #define xen_irq_disable()                                       \
  32 do {                                                            \
  33         vcpu_info_write(evtchn_upcall_mask, 1);                 \
  34         barrier();                                              \
  35 } while (0)
  36
  37 #define xen_irq_enable()                                        \
  38 do {                                                            \
  39         vcpu_info_t *_vcpu;                                     \
  40         barrier();                                              \
  41         _vcpu = current_vcpu_info();                            \
  42         _vcpu->evtchn_upcall_mask = 0;                          \
  43         barrier(); /* unmask then check (avoid races) */        \
  44         if (unlikely(_vcpu->evtchn_upcall_pending))             \
  45                 force_evtchn_callback();                        \
  46 } while (0)
  47
  48 #define arch_local_save_flags() xen_save_fl()
  49
  50 #define arch_local_irq_restore(flags) xen_restore_fl(flags)
  51
  52 #define arch_local_irq_disable()        xen_irq_disable()
  53
  54 #define arch_local_irq_enable() xen_irq_enable()
  55
  56 /*
  57  * Used in the idle loop; sti takes one instruction cycle
  58  * to complete:
  59  */
  60 #define arch_safe_halt HYPERVISOR_block
  61
  62 /*
  63  * Used when interrupts are already enabled or to
  64  * shutdown the processor:
  65  */
  66 #define halt() VOID(irqs_disabled()                                     \
  67                     ? HYPERVISOR_vcpu_op(VCPUOP_down,                   \
  68                                          smp_processor_id(), NULL)      \
  69                     : 0)
  70
  71 /*
  72  * For spinlocks, etc:
  73  */
  74 #define arch_local_irq_save()                                           \
  75 ({                                                                      \
  76         unsigned long flags = arch_local_save_flags();                  \
  77                                                                         \
  78         arch_local_irq_disable();                                       \
  79                                                                         \
  80         flags;                                                          \
  81 })
  82 #else
  83
  84 /* Offsets into shared_info_t. */
  85 #define evtchn_upcall_pending           /* 0 */
  86 #define evtchn_upcall_mask              1
  87
  88 #ifdef CONFIG_X86_64
  89 # define __REG_si %rsi
  90 # define __CPU_num PER_CPU_VAR(cpu_number)
  91 #else
  92 # define __REG_si %esi
  93 # define __CPU_num TI_cpu(%ebp)
  94 #endif
  95
  96 #ifdef CONFIG_XEN_VCPU_INFO_PLACEMENT
  97
  98 #define GET_VCPU_INFO           PER_CPU(vcpu_info, __REG_si)
  99 #define __DISABLE_INTERRUPTS    movb $1,PER_CPU_VAR(vcpu_info+evtchn_upcall_mask)
 100 #define __ENABLE_INTERRUPTS     movb $0,PER_CPU_VAR(vcpu_info+evtchn_upcall_mask)
 101 #define __TEST_PENDING          cmpb $0,PER_CPU_VAR(vcpu_info+evtchn_upcall_pending+0)
 102 #define DISABLE_INTERRUPTS(clb) __DISABLE_INTERRUPTS
 103 #define ENABLE_INTERRUPTS(clb)  __ENABLE_INTERRUPTS
 104
 105 #define __SIZEOF_DISABLE_INTERRUPTS 8
 106 #define __SIZEOF_TEST_PENDING   8
 107
 108 #else /* CONFIG_XEN_VCPU_INFO_PLACEMENT */
 109
 110 #define sizeof_vcpu_shift       6
 111
 112 #ifdef CONFIG_SMP
 113 #define GET_VCPU_INFO           movl __CPU_num,%esi                     ; \
 114                                 shl $sizeof_vcpu_shift,%esi             ; \
 115                                 add HYPERVISOR_shared_info,__REG_si
 116 #else
 117 #define GET_VCPU_INFO           mov HYPERVISOR_shared_info,__REG_si
 118 #endif
 119
 120 #define __DISABLE_INTERRUPTS    movb $1,evtchn_upcall_mask(__REG_si)
 121 #define __ENABLE_INTERRUPTS     movb $0,evtchn_upcall_mask(__REG_si)
 122 #define __TEST_PENDING          testb $0xFF,evtchn_upcall_pending(__REG_si)
 123 #define DISABLE_INTERRUPTS(clb) GET_VCPU_INFO                           ; \
 124                                 __DISABLE_INTERRUPTS
 125 #define ENABLE_INTERRUPTS(clb)  GET_VCPU_INFO                           ; \
 126                                 __ENABLE_INTERRUPTS
 127
 128 #define __SIZEOF_DISABLE_INTERRUPTS 4
 129 #define __SIZEOF_TEST_PENDING   3
 130
 131 #endif /* CONFIG_XEN_VCPU_INFO_PLACEMENT */
 132
 133 #ifndef CONFIG_X86_64
 134 #define INTERRUPT_RETURN                iret
 135 #define ENABLE_INTERRUPTS_SYSEXIT                                         \
 136         movb $0,evtchn_upcall_mask(%esi) /* __ENABLE_INTERRUPTS */      ; \
 137 sysexit_scrit:  /**** START OF SYSEXIT CRITICAL REGION ****/            ; \
 138         cmpb $0,evtchn_upcall_pending(%esi) /* __TEST_PENDING */        ; \
 139         jnz  14f        /* process more events if necessary... */       ; \
 140         movl PT_ESI(%esp), %esi                                         ; \
 141         sysexit                                                         ; \
 142 14:     movb $1,evtchn_upcall_mask(%esi) /* __DISABLE_INTERRUPTS */     ; \
 143         TRACE_IRQS_OFF                                                  ; \
 144 sysexit_ecrit:  /**** END OF SYSEXIT CRITICAL REGION ****/              ; \
 145         mov  $__KERNEL_PERCPU, %ecx                                     ; \
 146         push %esp                                                       ; \
 147         mov  %ecx, %fs                                                  ; \
 148         SET_KERNEL_GS %ecx                                              ; \
 149         call evtchn_do_upcall                                           ; \
 150         add  $4,%esp                                                    ; \
 151         jmp  ret_from_intr
 152 #endif
 153
 154
 155 #endif /* __ASSEMBLY__ */
 156
 157 #ifndef __ASSEMBLY__
 158 static inline int arch_irqs_disabled_flags(unsigned long flags)
 159 {
 160         return (flags != 0);
 161 }
 162
 163 #define arch_irqs_disabled()                                            \
 164 ({                                                                      \
 165         unsigned long flags = arch_local_save_flags();                  \
 166                                                                         \
 167         arch_irqs_disabled_flags(flags);                                \
 168 })
 169
 170 #else
 171
 172 #ifdef CONFIG_X86_64
 173 #define ARCH_LOCKDEP_SYS_EXIT           call lockdep_sys_exit_thunk
 174 #define ARCH_LOCKDEP_SYS_EXIT_IRQ       \
 175         TRACE_IRQS_ON; \
 176         ENABLE_INTERRUPTS(CLBR_NONE); \
 177         SAVE_REST; \
 178         LOCKDEP_SYS_EXIT; \
 179         RESTORE_REST; \
 180         __DISABLE_INTERRUPTS; \
 181         TRACE_IRQS_OFF;
 182
 183 #else
 184 #define ARCH_LOCKDEP_SYS_EXIT                   \
 185         pushl %eax;                             \
 186         pushl %ecx;                             \
 187         pushl %edx;                             \
 188         call lockdep_sys_exit;                  \
 189         popl %edx;                              \
 190         popl %ecx;                              \
 191         popl %eax;
 192
 193 #define ARCH_LOCKDEP_SYS_EXIT_IRQ
 194 #endif
 195
 196 #ifdef CONFIG_TRACE_IRQFLAGS
 197 #  define TRACE_IRQS_ON         call trace_hardirqs_on_thunk;
 198 #  define TRACE_IRQS_OFF        call trace_hardirqs_off_thunk;
 199 #else
 200 #  define TRACE_IRQS_ON
 201 #  define TRACE_IRQS_OFF
 202 #endif
 203 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 204 #  define LOCKDEP_SYS_EXIT      ARCH_LOCKDEP_SYS_EXIT
 205 #  define LOCKDEP_SYS_EXIT_IRQ  ARCH_LOCKDEP_SYS_EXIT_IRQ
 206 # else
 207 #  define LOCKDEP_SYS_EXIT
 208 #  define LOCKDEP_SYS_EXIT_IRQ
 209 # endif
 210
 211 #endif /* __ASSEMBLY__ */
 212 #endif