reactos/ntoskrnl/include/internal/i386/asmmacro.S

   1 /*
   2  * COPYRIGHT:       See COPYING in the top level directory
   3  * PROJECT:         ReactOS Kernel
   4  * FILE:            ntoskrnl/include/i386/asmmacro.S
   5  * PURPOSE:         Assembly Macros for Spinlocks and common Trap Code
   6  * PROGRAMMERS:     Alex Ionescu (alex@relsoft.net)
   7  *                  Timo Kreuzer (timo.kreuzer@reactos.org)
   8  */
   9
  10 // Arguments for idt
  11 #define INT_32_DPL0                 HEX(08E00)
  12 #define INT_32_DPL3                 HEX(0EE00)
  13
  14 //
  15 // These macros are inlined equivalents of KiAcquire/ReleaseSpinlock, that is,
  16 // they will not be compiled into non-SMP builds. Usage is as follows:
  17 //
  18 // .BeginYourFunction
  19 //      mov reg, lockaddr
  20 //      ACQUIRE_SPINLOCK(reg, .spin)
  21 //      <thread-safe code here>
  22 //      RELEASE_SPINLOCK(reg)
  23 //      <misc code here>
  24 //  retn
  25 //  #IFDEF CONFIG_SMP
  26 //  .spin
  27 //      <any necessary steps to be able to jump back safely>
  28 //       SPIN_ON_LOCK(reg, .BeginYourFunction)
  29 //  #ENDIF
  30 //
  31 #ifdef CONFIG_SMP
  32 #define LOCK lock
  33 #define ACQUIRE_SPINLOCK(x, y) \
  34     lock bts dword ptr [x], 0; \
  35     jb y
  36 #define RELEASE_SPINLOCK(x) mov byte ptr [x], 0
  37 #define SPIN_ON_LOCK(x, y) \
  38 1: \
  39     test dword ptr [x], 1; \
  40     jz y; \
  41     pause; \
  42     jmp 1b
  43 #else
  44 #define LOCK
  45 #define ACQUIRE_SPINLOCK(x, y)
  46 #define RELEASE_SPINLOCK(x)
  47 #endif
  48
  49 //
  50 // @name IDT
  51 //
  52 // This macro creates an IDT entry for the given handler
  53 //
  54 // @param Handler
  55 //        Pointer to the IDT handler
  56 //
  57 // @param Bits
  58 //        Descriptor Bits to associate
  59 //
  60 // @remark None.
  61 //
  62 MACRO(idt, Handler, Bits)
  63     .long \Handler
  64     .short \Bits
  65     .short KGDT_R0_CODE
  66 ENDM
  67
  68
  69 KI_PUSH_FAKE_ERROR_CODE = HEX(0001)
  70 KI_UNUSED               = HEX(0002)
  71 KI_NONVOLATILES_ONLY    = HEX(0004)
  72 KI_FAST_SYSTEM_CALL     = HEX(0008)
  73 KI_SOFTWARE_TRAP        = HEX(0010)
  74 KI_HARDWARE_INT         = HEX(0020)
  75 KI_DONT_SAVE_SEGS       = HEX(0100)
  76
  77 MACRO(KiEnterTrap, Flags)
  78     LOCAL kernel_trap
  79     LOCAL not_v86_trap
  80     LOCAL set_sane_segs
  81
  82     /* Check what kind of trap frame this trap requires */
  83     if (Flags AND KI_FAST_SYSTEM_CALL)
  84
  85         /* SYSENTER requires us to build a complete ring transition trap frame */
  86         FrameSize = KTRAP_FRAME_V86_ES
  87
  88         /* Fixup fs. cx is free to clobber */
  89         mov cx, KGDT_R0_PCR
  90         mov fs, cx
  91
  92         /* Get pointer to the TSS */
  93         mov ecx, fs:[KPCR_TSS]
  94
  95         /* Get a stack pointer */
  96         mov esp, [ecx + KTSS_ESP0]
  97
  98     elseif (Flags AND KI_SOFTWARE_TRAP)
  99
 100         /* Software traps need a complete non-ring transition trap frame */
 101         FrameSize = KTRAP_FRAME_ESP
 102
 103         /* Software traps need to get their EIP from the caller's frame */
 104         pop eax
 105
 106     elseif (Flags AND KI_PUSH_FAKE_ERROR_CODE)
 107
 108         /* If the trap doesn't have an error code, we'll make space for it */
 109         FrameSize = KTRAP_FRAME_EIP
 110
 111     else
 112
 113         /* The trap already has an error code, so just make space for the rest */
 114         FrameSize = KTRAP_FRAME_ERROR_CODE
 115
 116     endif
 117
 118     /* Make space for this frame */
 119     sub esp, FrameSize
 120
 121     /* Save nonvolatile registers */
 122     mov [esp + KTRAP_FRAME_EBP], ebp
 123     mov [esp + KTRAP_FRAME_EBX], ebx
 124     mov [esp + KTRAP_FRAME_ESI], esi
 125     mov [esp + KTRAP_FRAME_EDI], edi
 126
 127     /* Save eax for system calls, for use by the C handler */
 128     mov [esp + KTRAP_FRAME_EAX], eax
 129
 130     /* Does the caller want nonvolatiles only? */
 131     if ((Flags AND KI_NONVOLATILES_ONLY) == 0)
 132         /* Otherwise, save the volatiles as well */
 133         mov [esp + KTRAP_FRAME_ECX], ecx
 134         mov [esp + KTRAP_FRAME_EDX], edx
 135     endif
 136
 137     /* Save segment registers? */
 138     if ((Flags AND KI_DONT_SAVE_SEGS) == 0)
 139
 140         /* Check for V86 mode */
 141         test byte ptr [esp + KTRAP_FRAME_EFLAGS + 2], (EFLAGS_V86_MASK >> 16)
 142         jz not_v86_trap
 143
 144             /* Restore V8086 segments into Protected Mode segments */
 145             mov eax, [esp + KTRAP_FRAME_V86_DS]
 146             mov ecx, [esp + KTRAP_FRAME_V86_ES]
 147             mov [esp + KTRAP_FRAME_DS], eax
 148             mov [esp + KTRAP_FRAME_ES], ecx
 149             mov eax, [esp + KTRAP_FRAME_V86_FS]
 150             mov ecx, [esp + KTRAP_FRAME_V86_GS]
 151             mov [esp + KTRAP_FRAME_FS], eax
 152             mov [esp + KTRAP_FRAME_GS], ecx
 153             jmp set_sane_segs
 154
 155         not_v86_trap:
 156
 157             /* Save segment selectors */
 158             mov eax, ds
 159             mov ecx, es
 160             mov [esp + KTRAP_FRAME_DS], eax
 161             mov [esp + KTRAP_FRAME_ES], ecx
 162             mov eax, fs
 163             mov ecx, gs
 164             mov [esp + KTRAP_FRAME_FS], eax
 165             mov [esp + KTRAP_FRAME_GS], ecx
 166
 167     endif
 168
 169 set_sane_segs:
 170     /* Load correct data segments */
 171     mov ax, KGDT_R3_DATA OR RPL_MASK
 172     mov ds, ax
 173     mov es, ax
 174
 175     /* Fast system calls have fs already fixed */
 176     if ((Flags AND KI_FAST_SYSTEM_CALL) == 0)
 177         /* Otherwise fix fs now */
 178         mov ax, KGDT_R0_PCR
 179         mov fs, ax
 180     endif
 181
 182     /* Set parameter 1 (ECX) to point to the frame */
 183     mov ecx, esp
 184
 185     /* Clear direction flag */
 186     cld
 187
 188 ENDM
 189
 190 MACRO(TRAP_ENTRY, Trap, Flags)
 191 EXTERN @&Trap&Handler@4 :PROC
 192     PUBLIC _&Trap
 193     _&Trap:
 194     KiEnterTrap Flags
 195     jmp @&Trap&Handler@4
 196 ENDM
 197