|
| 1 | +/******************************************************* |
| 2 | + * ------------------------------------------------- * |
| 3 | + * | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | * |
| 4 | + * ------------------------------------------------- * |
| 5 | + * | 0 | 8 | 16 | 24 | * |
| 6 | + * ------------------------------------------------- * |
| 7 | + * | t.fctx | t.data | r2 | r6 | * |
| 8 | + * ------------------------------------------------- * |
| 9 | + * ------------------------------------------------- * |
| 10 | + * | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | * |
| 11 | + * ------------------------------------------------- * |
| 12 | + * | 32 | 40 | 48 | 56 | * |
| 13 | + * ------------------------------------------------- * |
| 14 | + * | r7 | r8 | r9 | r10 | * |
| 15 | + * ------------------------------------------------- * |
| 16 | + * ------------------------------------------------- * |
| 17 | + * | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | * |
| 18 | + * ------------------------------------------------- * |
| 19 | + * | 64 | 72 | 80 | 88 | * |
| 20 | + * ------------------------------------------------- * |
| 21 | + * | r11 | r12 | r13 | r14 | * |
| 22 | + * ------------------------------------------------- * |
| 23 | + * ------------------------------------------------- * |
| 24 | + * | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | * |
| 25 | + * ------------------------------------------------- * |
| 26 | + * | 96 | 104 | 112 | 120 | * |
| 27 | + * ------------------------------------------------- * |
| 28 | + * | f8 | f9 | f10 | f11 | * |
| 29 | + * ------------------------------------------------- * |
| 30 | + * ------------------------------------------------- * |
| 31 | + * | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | * |
| 32 | + * ------------------------------------------------- * |
| 33 | + * | 128 | 136 | 144 | 152 | * |
| 34 | + * ------------------------------------------------- * |
| 35 | + * | f12 | f13 | f14 | f15 | * |
| 36 | + * ------------------------------------------------- * |
| 37 | + * ------------------------------------------------- * |
| 38 | + * | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | * |
| 39 | + * ------------------------------------------------- * |
| 40 | + * | 160 | 168 | 176 | | * |
| 41 | + * ------------------------------------------------- * |
| 42 | + * | fpc | pc | | | * |
| 43 | + * ------------------------------------------------- * |
| 44 | + *******************************************************/ |
| 45 | + |
| 46 | +.text |
| 47 | +.align 8 |
| 48 | +.global jump_fcontext |
| 49 | +.type jump_fcontext, @function |
| 50 | + |
| 51 | +#define ARG_OFFSET 0 |
| 52 | +#define GR_OFFSET 16 |
| 53 | +#define FP_OFFSET 96 |
| 54 | +#define FPC_OFFSET 160 |
| 55 | +#define PC_OFFSET 168 |
| 56 | +#define CONTEXT_SIZE 176 |
| 57 | + |
| 58 | +#define REG_SAVE_AREA_SIZE 160 |
| 59 | + |
| 60 | +/* |
| 61 | +
|
| 62 | +typedef void* fcontext_t; |
| 63 | +
|
| 64 | +struct transfer_t { |
| 65 | + fcontext_t fctx; |
| 66 | + void * data; |
| 67 | +}; |
| 68 | +
|
| 69 | +transfer_t jump_fcontext( fcontext_t const to, |
| 70 | + void * data); |
| 71 | +
|
| 72 | +Incoming args |
| 73 | +r2 - Hidden argument to the location where the return transfer_t needs to be returned |
| 74 | +r3 - Context we want to switch to |
| 75 | +r4 - Data pointer |
| 76 | +
|
| 77 | +*/ |
| 78 | + |
| 79 | +jump_fcontext: |
| 80 | + .machine "z10" |
| 81 | + /* Reserve stack space to store the current context. */ |
| 82 | + aghi %r15,-CONTEXT_SIZE |
| 83 | + |
| 84 | + /* Save the argument register holding the location of the return value. */ |
| 85 | + stg %r2,GR_OFFSET(%r15) |
| 86 | + |
| 87 | + /* Save the call-saved general purpose registers. */ |
| 88 | + stmg %r6,%r14,GR_OFFSET+8(%r15) |
| 89 | + |
| 90 | + /* Save call-saved floating point registers. */ |
| 91 | + std %f8,FP_OFFSET(%r15) |
| 92 | + std %f9,FP_OFFSET+8(%r15) |
| 93 | + std %f10,FP_OFFSET+16(%r15) |
| 94 | + std %f11,FP_OFFSET+24(%r15) |
| 95 | + std %f12,FP_OFFSET+32(%r15) |
| 96 | + std %f13,FP_OFFSET+40(%r15) |
| 97 | + std %f14,FP_OFFSET+48(%r15) |
| 98 | + std %f15,FP_OFFSET+56(%r15) |
| 99 | + |
| 100 | + /* Save the return address as current pc. */ |
| 101 | + stg %r14,PC_OFFSET(%r15) |
| 102 | + |
| 103 | + /* Save the floating point control register. */ |
| 104 | + stfpc FPC_OFFSET(%r15) |
| 105 | + |
| 106 | + /* Backup the stack pointer pointing to the old context-data into r1. */ |
| 107 | + lgr %r1,%r15 |
| 108 | + |
| 109 | + /* Load the new context pointer as stack pointer. */ |
| 110 | + lgr %r15,%r3 |
| 111 | + |
| 112 | + /* Restore the call-saved GPRs from the new context. */ |
| 113 | + lmg %r6,%r14,GR_OFFSET+8(%r15) |
| 114 | + |
| 115 | + /* Restore call-saved floating point registers. */ |
| 116 | + ld %f8,FP_OFFSET(%r15) |
| 117 | + ld %f9,FP_OFFSET+8(%r15) |
| 118 | + ld %f10,FP_OFFSET+16(%r15) |
| 119 | + ld %f11,FP_OFFSET+24(%r15) |
| 120 | + ld %f12,FP_OFFSET+32(%r15) |
| 121 | + ld %f13,FP_OFFSET+40(%r15) |
| 122 | + ld %f14,FP_OFFSET+48(%r15) |
| 123 | + ld %f15,FP_OFFSET+56(%r15) |
| 124 | + |
| 125 | + /* Load the floating point control register. */ |
| 126 | + lfpc FPC_OFFSET(%r15) |
| 127 | + |
| 128 | + /* Restore PC - the location where we will jump to at the end. */ |
| 129 | + lg %r5,PC_OFFSET(%r15) |
| 130 | + |
| 131 | + ltg %r2,GR_OFFSET(%r15) |
| 132 | + jnz use_return_slot |
| 133 | + |
| 134 | + /* We restore a make_fcontext context. Use the function |
| 135 | + argument slot in the context we just saved and allocate the |
| 136 | + register save area for the target function. */ |
| 137 | + la %r2,ARG_OFFSET(%r1) |
| 138 | + aghi %r15,-REG_SAVE_AREA_SIZE |
| 139 | + |
| 140 | +use_return_slot: |
| 141 | + /* Save the two fields in transfer_t. When calling a |
| 142 | + make_fcontext function this becomes the function argument of |
| 143 | + the target function, otherwise it will be the return value of |
| 144 | + jump_fcontext. */ |
| 145 | + stg %r1,0(%r2) |
| 146 | + stg %r4,8(%r2) |
| 147 | + |
| 148 | + /* Free the restored context. */ |
| 149 | + aghi %r15,CONTEXT_SIZE |
| 150 | + |
| 151 | + /* Jump to the PC loaded from the new context. */ |
| 152 | + br %r5 |
| 153 | + |
| 154 | + |
| 155 | +.size jump_fcontext,.-jump_fcontext |
| 156 | +.section .note.GNU-stack,"",%progbits |
0 commit comments