Changeset c5cbc099


Ignore:
Timestamp:
Aug 21, 2020, 7:45:51 AM (16 months ago)
Author:
Peter A. Buhr <pabuhr@…>
Branches:
arm-eh, jacob/cs343-translation, master, new-ast-unique-expr
Children:
482fa08
Parents:
636d115b
Message:

temporarily change from 32-bit to 64-bit and get it working

File:
1 edited

Legend:

Unmodified
Added
Removed
  • libcfa/src/concurrency/CtxSwitch-arm.S

    r636d115b rc5cbc099  
    1         @ 32 bit ARM context switch
    2         @ This function assumes that r9 has no special meaning on the platform it's
    3         @ being built on.
    4         @ If r9 is special, uncomment the following line and it will be left alone
     1//
     2// Cforall Version 1.0.0 Copyright (C) 2016 University of Waterloo
     3//
     4// CtxSwitch-arm.S --
     5//
     6// Author           : Peter A. Buhr
     7// Created On       : Sun Aug 16 07:50:13 2020
     8// Last Modified By : Peter A. Buhr
     9// Last Modified On : Thu Aug 20 18:43:51 2020
     10// Update Count     : 24
     11//
    512
    6         @ #define R9_SPECIAL
     13// The context switch routine requires the initial the stack of a thread to
     14// look like the thread has saved its context in the normal manner.
    715
    8         #define PTR_BYTE        4
    9         #define SP_OFFSET       ( 0 * PTR_BYTE )
    10         #define FP_OFFSET       ( 1 * PTR_BYTE )
    11         #define PC_OFFSET       ( 2 * PTR_BYTE )
     16// Offsets must synchronized with the __stack_context_t in invoke.h.
     17
     18#define PTR_BYTE        8
     19#define SP_OFFSET       ( 0 * PTR_BYTE )
     20#define FP_OFFSET       ( 1 * PTR_BYTE )
     21
     22// Context switch between coroutines/tasks.
     23//   void __cfactx_switch( struct __stack_context_t * from, struct __stack_context_t * to ) ;
     24// Arguments "from" in register x0, "to" in register x1.
     25
     26#define SAVE            20 * 8
     27
     28        .file "CtxSwitch-arm.S"
     29        .text
     30        .align 2
     31        .global __cfactx_switch
     32        .type __cfactx_switch, @function
     33__cfactx_switch:
     34
     35        sub  sp, sp, #SAVE                                      // push stack
     36
     37        // Save volatile GP registers x19-x30 on the stack.
     38
     39        stp  x19, x20, [sp, #0x00]
     40        stp  x21, x22, [sp, #0x10]
     41        stp  x23, x24, [sp, #0x20]
     42        stp  x25, x26, [sp, #0x30]
     43        stp  x27, x28, [sp, #0x40]
     44        stp  x29, x30, [sp, #0x50]                      // x29 => fp
     45
     46        // Save volatile SIMD/FPU registers d8-d15 on the stack.
     47
     48        stp  d8,  d9,  [sp, #0x60]
     49        stp  d10, d11, [sp, #0x70]
     50        stp  d12, d13, [sp, #0x80]
     51        stp  d14, d15, [sp, #0x90]
     52
     53        // Save old context in the "from" area.
     54
     55        mov  x4, sp                                                     // cannot store sp directly
     56        str  x4, [x0, #SP_OFFSET]
     57        str  fp, [x0, #FP_OFFSET]
     58
     59        // Load new context from the "to" area.
     60
     61        ldr  fp, [x1, #FP_OFFSET]
     62        ldr  x4, [x1, #SP_OFFSET]
     63        mov  sp, x4                                                     // cannot store sp directly
     64
     65        // Load volatile GP registers x19-x30 from the stack.
     66
     67        ldp  x19, x20, [sp, #0x00]
     68        ldp  x21, x22, [sp, #0x10]
     69        ldp  x23, x24, [sp, #0x20]
     70        ldp  x25, x26, [sp, #0x30]
     71        ldp  x27, x28, [sp, #0x40]
     72        ldp  x29, x30, [sp, #0x50]
     73       
     74        // Load volatile SIMD/FPU registers d8-d15 from the stack.
     75
     76        ldp  d8,  d9,  [sp, #0x60]
     77        ldp  d10, d11, [sp, #0x70]
     78        ldp  d12, d13, [sp, #0x80]
     79        ldp  d14, d15, [sp, #0x90]
     80
     81        add  sp, sp, #SAVE                                      // pop stack
     82        ret                                                                     // return to new thread (mov pc, x30)
     83
     84        .size __cfactx_switch, .-__cfactx_switch
     85        .section .note.GNU-stack,"",%progbits // mark no executable stack needed
     86
     87// Stub to create new stacks which can be context switched to
     88//   void __cfactx_invoke_stub( void );
    1289
    1390        .text
    14         .align  2
    15         .global __cfactx_switch
    16         .type   __cfactx_switch, %function
     91        .align 2
     92        .global __cfactx_invoke_stub
     93        .type __cfactx_invoke_stub, @function
     94__cfactx_invoke_stub:
     95        mov x0, x19                                                     // load main as parameter 0
     96        mov x1, x20                                                     // load this as parameter 1
     97        mov x30, x21                                            // load coroutine invoke routine
     98        ret                                                                     //   and jmp to it (mov pc, x30)
     99        .size __cfactx_invoke_stub, .-__cfactx_invoke_stub
    17100
    18 __cfactx_switch:
    19         @ save callee-saved registers: r4-r8, r10, r11, r13(sp) (plus r9 depending on platform specification)
    20         @ I've seen reference to 31 registers on 64-bit, if this is the case, more need to be saved
    21         @ save thread state registers: r14(lr)
    22         @ r12(ip) is intra-procedure-call scratch register, does not need saving between function calls
    23 
    24         #ifdef R9_SPECIAL
    25         stmfd r13!, {r4-r8,r10,r11,r14}
    26         #else
    27         stmfd r13!, {r4-r11,r14}
    28         #endif // R9_SPECIAL
    29 
    30         @ save floating point registers: s16-s31
    31         vstmdb r13!, {s16-s31}
    32 
    33         @ save frame pointer and stack pointer to outgoing datastructure
    34         str sp, [r0, #SP_OFFSET]
    35         str fp, [r0, #FP_OFFSET]
    36 
    37         @ restore frame pointer and stack pointer from incoming datastructure
    38         ldr fp, [r1, #FP_OFFSET]
    39         ldr sp, [r1, #SP_OFFSET]
    40 
    41         @ restore floating point registers: s16-s31
    42         vldm r13!, {s16-s31}
    43         @ restore r14(lr)
    44         @ restore 64-bit extra registers?
    45         @ restore callee-saved registers: r4-r8, r10, r11, r13
    46 
    47         #ifdef R9_SPECIAL
    48         ldmfd r13!, {r4-r8,r10,r11,r15}
    49         #else
    50         ldmfd r13!, {r4-r11,r14}    @ loading r14 back into r15 returns
    51 
    52         mov r15, r14
    53         #endif // R9_SPECIAL
    54 
    55         .text
    56         .align  2
    57         .global __cfactx_invoke_stub
    58         .type   __cfactx_invoke_stub, %function
    59 
    60 __cfactx_invoke_stub:
    61         ldmfd r13!, {r0-r1}
    62         mov r15, r1
     101// Local Variables: //
     102// mode: c //
     103// tab-width: 4 //
     104// End: //
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