1 // Copyright 2016 The Go Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style 3 // license that can be found in the LICENSE file. 4 5 /* 6 * void crosscall_s390x(void (*fn)(void), void *g) 7 * 8 * Calling into the go tool chain, where all registers are caller save. 9 * Called from standard s390x C ABI, where r6-r13, r15, and f8-f15 are 10 * callee-save, so they must be saved explicitly. 11 */ 12 .globl crosscall_s390x 13 crosscall_s390x: 14 /* save r6-r15 in the register save area of the calling function */ 15 stmg %r6, %r15, 48(%r15) 16 17 /* allocate 64 bytes of stack space to save f8-f15 */ 18 lay %r15, -64(%r15) 19 20 /* save callee-saved floating point registers */ 21 std %f8, 0(%r15) 22 std %f9, 8(%r15) 23 std %f10, 16(%r15) 24 std %f11, 24(%r15) 25 std %f12, 32(%r15) 26 std %f13, 40(%r15) 27 std %f14, 48(%r15) 28 std %f15, 56(%r15) 29 30 /* restore g pointer */ 31 lgr %r13, %r3 32 33 /* call fn */ 34 basr %r14, %r2 35 36 /* restore floating point registers */ 37 ld %f8, 0(%r15) 38 ld %f9, 8(%r15) 39 ld %f10, 16(%r15) 40 ld %f11, 24(%r15) 41 ld %f12, 32(%r15) 42 ld %f13, 40(%r15) 43 ld %f14, 48(%r15) 44 ld %f15, 56(%r15) 45 46 /* de-allocate stack frame */ 47 la %r15, 64(%r15) 48 49 /* restore general purpose registers */ 50 lmg %r6, %r15, 48(%r15) 51 52 br %r14 /* restored by lmg */ 53 54 #ifdef __ELF__ 55 .section .note.GNU-stack,"",%progbits 56 #endif 57
