include/asm-nios2nommu/entry.h

   1 /*
   2  * Hacked from m68knommu port.
   3  *
   4  *  Copyright(C) 2004 Microtronix Datacom Ltd.
   5  *
   6  * All rights reserved.
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful, but
  14  * WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
  16  * NON INFRINGEMENT.  See the GNU General Public License for more
  17  * details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  22  *
  23  */
  24
  25 #ifndef __NIOS2NOMMU_ENTRY_H
  26 #define __NIOS2NOMMU_ENTRY_H
  27
  28 #ifdef __ASSEMBLY__
  29
  30 #include <asm/setup.h>
  31 #include <asm/page.h>
  32 #include <asm/asm-offsets.h>
  33
  34 /*
  35  * Stack layout in 'ret_from_exception':
  36  *
  37  * This allows access to the syscall arguments in registers r4-r8
  38  *
  39  *       0(sp) - r8
  40  *       4(sp) - r9
  41  *       8(sp) - r10
  42  *       C(sp) - r11
  43  *      10(sp) - r12
  44  *      14(sp) - r13
  45  *      18(sp) - r14
  46  *      1C(sp) - r15
  47  *      20(sp) - r1
  48  *      24(sp) - r2
  49  *      28(sp) - r3
  50  *      2C(sp) - r4
  51  *      30(sp) - r5
  52  *      34(sp) - r6
  53  *      38(sp) - r7
  54  *      3C(sp) - orig_r2
  55  *      40(sp) - ra
  56  *      44(sp) - fp
  57  *      48(sp) - sp
  58  *      4C(sp) - gp
  59  *      50(sp) - estatus
  60  *      54(sp) - status_extension
  61  *      58(sp) - ea
  62  *
  63  */
  64
  65 /* process bits for task_struct.flags */
  66 PF_TRACESYS_OFF = 3
  67 PF_TRACESYS_BIT = 5
  68 PF_PTRACED_OFF = 3
  69 PF_PTRACED_BIT = 4
  70 PF_DTRACE_OFF = 1
  71 PF_DTRACE_BIT = 5
  72
  73 LENOSYS = 38
  74
  75 /*
  76  * This defines the normal kernel pt-regs layout.
  77  *
  78  */
  79
  80 /*
  81  * Standard Nios2 interrupt entry and exit macros.
  82  * Must be called with interrupts disabled.
  83  */
  84 .macro SAVE_ALL
  85         movia   r24,status_extension    // Read status extension
  86         ldw     r24,0(r24)
  87         andi    r24,r24,PS_S_ASM
  88         bne     r24,r0,1f               // In supervisor mode, already on kernel stack
  89         movia   r24,_current_thread     // Switch to current kernel stack
  90         ldw     r24,0(r24)              //  using the thread_info
  91         addi    r24,r24,THREAD_SIZE_ASM-PT_REGS_SIZE
  92         stw     sp,PT_SP(r24)           // Save user stack before changing
  93         mov     sp,r24
  94         br      2f
  95
  96 1:      mov     r24,sp
  97         addi    sp,sp,-PT_REGS_SIZE     // Backup the kernel stack pointer
  98         stw     r24,PT_SP(sp)
  99 2:      stw     r1,PT_R1(sp)
 100         stw     r2,PT_R2(sp)
 101         stw     r3,PT_R3(sp)
 102         stw     r4,PT_R4(sp)
 103         stw     r5,PT_R5(sp)
 104         stw     r6,PT_R6(sp)
 105         stw     r7,PT_R7(sp)
 106         stw     r8,PT_R8(sp)
 107         stw     r9,PT_R9(sp)
 108         stw     r10,PT_R10(sp)
 109         stw     r11,PT_R11(sp)
 110         stw     r12,PT_R12(sp)
 111         stw     r13,PT_R13(sp)
 112         stw     r14,PT_R14(sp)
 113         stw     r15,PT_R15(sp)
 114         stw     r2,PT_ORIG_R2(sp)
 115         stw     ra,PT_RA(sp)
 116         stw     fp,PT_FP(sp)
 117         stw     gp,PT_GP(sp)
 118         rdctl   r24,estatus
 119         stw     r24,PT_ESTATUS(sp)
 120         movia   r24,status_extension    // Read status extension
 121         ldw     r1,0(r24)
 122         stw     r1,PT_STATUS_EXTENSION(sp)      // Store user/supervisor status
 123         ORI32   r1,r1,PS_S_ASM                  // Set supervisor mode
 124         stw     r1,0(r24)
 125         stw     ea,PT_EA(sp)
 126 .endm
 127
 128 .macro RESTORE_ALL
 129         ldw     r1,PT_STATUS_EXTENSION(sp)      // Restore user/supervisor status
 130         movia   r24,status_extension
 131         stw     r1,0(r24)
 132         ldw     r1,PT_R1(sp)            // Restore registers
 133         ldw     r2,PT_R2(sp)
 134         ldw     r3,PT_R3(sp)
 135         ldw     r4,PT_R4(sp)
 136         ldw     r5,PT_R5(sp)
 137         ldw     r6,PT_R6(sp)
 138         ldw     r7,PT_R7(sp)
 139         ldw     r8,PT_R8(sp)
 140         ldw     r9,PT_R9(sp)
 141         ldw     r10,PT_R10(sp)
 142         ldw     r11,PT_R11(sp)
 143         ldw     r12,PT_R12(sp)
 144         ldw     r13,PT_R13(sp)
 145         ldw     r14,PT_R14(sp)
 146         ldw     r15,PT_R15(sp)
 147         ldw     ra,PT_RA(sp)
 148         ldw     fp,PT_FP(sp)
 149         ldw     gp,PT_GP(sp)
 150         ldw     r24,PT_ESTATUS(sp)
 151         wrctl   estatus,r24
 152         ldw     ea,PT_EA(sp)
 153         ldw     sp,PT_SP(sp)            // Restore sp last
 154 .endm
 155
 156 .macro  SAVE_SWITCH_STACK
 157         addi    sp,sp,-SWITCH_STACK_SIZE
 158         stw     r16,SW_R16(sp)
 159         stw     r17,SW_R17(sp)
 160         stw     r18,SW_R18(sp)
 161         stw     r19,SW_R19(sp)
 162         stw     r20,SW_R20(sp)
 163         stw     r21,SW_R21(sp)
 164         stw     r22,SW_R22(sp)
 165         stw     r23,SW_R23(sp)
 166         stw     fp,SW_FP(sp)
 167         stw     gp,SW_GP(sp)
 168         stw     ra,SW_RA(sp)
 169 .endm
 170
 171 .macro  RESTORE_SWITCH_STACK
 172         ldw     r16,SW_R16(sp)
 173         ldw     r17,SW_R17(sp)
 174         ldw     r18,SW_R18(sp)
 175         ldw     r19,SW_R19(sp)
 176         ldw     r20,SW_R20(sp)
 177         ldw     r21,SW_R21(sp)
 178         ldw     r22,SW_R22(sp)
 179         ldw     r23,SW_R23(sp)
 180         ldw     fp,SW_FP(sp)
 181         ldw     gp,SW_GP(sp)
 182         ldw     ra,SW_RA(sp)
 183         addi    sp,sp,SWITCH_STACK_SIZE
 184 .endm
 185
 186 #endif /* __ASSEMBLY__ */
 187 #endif /* __NIOS2NOMMU_ENTRY_H */