1 /* asm-common-s390x.h  -  Common macros for zSeries assembly
2  *
3  * Copyright (C) 2020 Jussi Kivilinna <jussi.kivilinna@iki.fi>
4  *
5  * This file is part of Libgcrypt.
6  *
7  * Libgcrypt is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU Lesser General Public License as
9  * published by the Free Software Foundation; either version 2.1 of
10  * the License, or (at your option) any later version.
11  *
12  * Libgcrypt is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with this program; if not, see <http://www.gnu.org/licenses/>.
19  */
20 
21 #ifndef GCRY_ASM_COMMON_S390X_H
22 #define GCRY_ASM_COMMON_S390X_H
23 
24 #include <config.h>
25 
26 #ifdef HAVE_GCC_ASM_ELF_DIRECTIVES
27 # define ELF(...) __VA_ARGS__
28 #else
29 # define ELF(...) /*_*/
30 #endif
31 
32 #ifdef HAVE_GCC_ASM_CFI_DIRECTIVES
33 /* CFI directives to emit DWARF stack unwinding information. */
34 # define CFI_STARTPROC()            .cfi_startproc
35 # define CFI_ENDPROC()              .cfi_endproc
36 # define CFI_REMEMBER_STATE()       .cfi_remember_state
37 # define CFI_RESTORE_STATE()        .cfi_restore_state
38 # define CFI_ADJUST_CFA_OFFSET(off) .cfi_adjust_cfa_offset off
39 # define CFI_REL_OFFSET(reg,off)    .cfi_rel_offset reg, off
40 # define CFI_DEF_CFA_REGISTER(reg)  .cfi_def_cfa_register reg
41 # define CFI_REGISTER(ro,rn)        .cfi_register ro, rn
42 # define CFI_RESTORE(reg)           .cfi_restore reg
43 
44 /* CFA expressions are used for pointing CFA and registers to
45  * SP relative offsets. */
46 # define DW_REGNO_SP 15
47 
48 /* Fixed length encoding used for integers for now. */
49 # define DW_SLEB128_7BIT(value) \
50 	0x00|((value) & 0x7f)
51 # define DW_SLEB128_28BIT(value) \
52 	0x80|((value)&0x7f), \
53 	0x80|(((value)>>7)&0x7f), \
54 	0x80|(((value)>>14)&0x7f), \
55 	0x00|(((value)>>21)&0x7f)
56 
57 # define CFI_CFA_ON_STACK(rsp_offs,cfa_depth) \
58 	.cfi_escape \
59 	  0x0f, /* DW_CFA_def_cfa_expression */ \
60 	    DW_SLEB128_7BIT(11), /* length */ \
61 	  0x7f, /* DW_OP_breg15, rsp + constant */ \
62 	    DW_SLEB128_28BIT(rsp_offs), \
63 	  0x06, /* DW_OP_deref */ \
64 	  0x23, /* DW_OP_plus_constu */ \
65 	    DW_SLEB128_28BIT((cfa_depth)+160)
66 
67 # define CFI_REG_ON_STACK(regno,rsp_offs) \
68 	.cfi_escape \
69 	  0x10, /* DW_CFA_expression */ \
70 	    DW_SLEB128_7BIT(regno), \
71 	    DW_SLEB128_7BIT(5), /* length */ \
72 	  0x7f, /* DW_OP_breg15, rsp + constant */ \
73 	    DW_SLEB128_28BIT(rsp_offs)
74 
75 #else
76 # define CFI_STARTPROC()
77 # define CFI_ENDPROC()
78 # define CFI_REMEMBER_STATE()
79 # define CFI_RESTORE_STATE()
80 # define CFI_ADJUST_CFA_OFFSET(off)
81 # define CFI_REL_OFFSET(reg,off)
82 # define CFI_DEF_CFA_REGISTER(reg)
83 # define CFI_REGISTER(ro,rn)
84 # define CFI_RESTORE(reg)
85 
86 # define CFI_CFA_ON_STACK(rsp_offs,cfa_depth)
87 # define CFI_REG_ON_STACK(reg,rsp_offs)
88 #endif
89 
90 #endif /* GCRY_ASM_COMMON_AMD64_H */
91