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1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _SELFTESTS_POWERPC_BASIC_ASM_H
3 #define _SELFTESTS_POWERPC_BASIC_ASM_H
4 
5 #include <ppc-asm.h>
6 #include <asm/unistd.h>
7 
8 #ifdef __powerpc64__
9 #define PPC_LL		ld
10 #define PPC_STL		std
11 #define PPC_STLU	stdu
12 #else
13 #define PPC_LL		lwz
14 #define PPC_STL		stw
15 #define PPC_STLU	stwu
16 #endif
17 
18 #define LOAD_REG_IMMEDIATE(reg, expr) \
19 	lis	reg, (expr)@highest;	\
20 	ori	reg, reg, (expr)@higher;	\
21 	rldicr	reg, reg, 32, 31;	\
22 	oris	reg, reg, (expr)@high;	\
23 	ori	reg, reg, (expr)@l;
24 
25 /*
26  * Note: These macros assume that variables being stored on the stack are
27  * sizeof(long), while this is usually the case it may not always be the
28  * case for each use case.
29  */
30 #ifdef  __powerpc64__
31 
32 // ABIv2
33 #if defined(_CALL_ELF) && _CALL_ELF == 2
34 #define STACK_FRAME_MIN_SIZE 32
35 #define STACK_FRAME_TOC_POS  24
36 #define __STACK_FRAME_PARAM(_param)  (32 + ((_param)*8))
37 #define __STACK_FRAME_LOCAL(_num_params, _var_num)  \
38 	((STACK_FRAME_PARAM(_num_params)) + ((_var_num)*8))
39 
40 #else // ABIv1 below
41 #define STACK_FRAME_MIN_SIZE 112
42 #define STACK_FRAME_TOC_POS  40
43 #define __STACK_FRAME_PARAM(i)  (48 + ((i)*8))
44 
45 /*
46  * Caveat: if a function passed more than 8 doublewords, the caller will have
47  * made more space... which would render the 112 incorrect.
48  */
49 #define __STACK_FRAME_LOCAL(_num_params, _var_num)  \
50 	(112 + ((_var_num)*8))
51 
52 
53 #endif // ABIv2
54 
55 // Common 64-bit
56 #define STACK_FRAME_LR_POS   16
57 #define STACK_FRAME_CR_POS   8
58 
59 #else // 32-bit below
60 
61 #define STACK_FRAME_MIN_SIZE 16
62 #define STACK_FRAME_LR_POS   4
63 
64 #define __STACK_FRAME_PARAM(_param)  (STACK_FRAME_MIN_SIZE + ((_param)*4))
65 #define __STACK_FRAME_LOCAL(_num_params, _var_num)  \
66 	((STACK_FRAME_PARAM(_num_params)) + ((_var_num)*4))
67 
68 #endif // __powerpc64__
69 
70 /* Parameter x saved to the stack */
71 #define STACK_FRAME_PARAM(var)    __STACK_FRAME_PARAM(var)
72 
73 /* Local variable x saved to the stack after x parameters */
74 #define STACK_FRAME_LOCAL(num_params, var)    \
75 	__STACK_FRAME_LOCAL(num_params, var)
76 
77 /*
78  * It is very important to note here that _extra is the extra amount of
79  * stack space needed. This space can be accessed using STACK_FRAME_PARAM()
80  * or STACK_FRAME_LOCAL() macros.
81  *
82  * r1 and r2 are not defined in ppc-asm.h (instead they are defined as sp
83  * and toc). Kernel programmers tend to prefer rX even for r1 and r2, hence
84  * %1 and %r2. r0 is defined in ppc-asm.h and therefore %r0 gets
85  * preprocessed incorrectly, hence r0.
86  */
87 #define PUSH_BASIC_STACK(_extra) \
88 	mflr	 r0; \
89 	PPC_STL	 r0, STACK_FRAME_LR_POS(%r1); \
90 	PPC_STLU %r1, -(((_extra + 15) & ~15) + STACK_FRAME_MIN_SIZE)(%r1);
91 
92 #define POP_BASIC_STACK(_extra) \
93 	addi	%r1, %r1, (((_extra + 15) & ~15) + STACK_FRAME_MIN_SIZE); \
94 	PPC_LL	r0, STACK_FRAME_LR_POS(%r1); \
95 	mtlr	r0;
96 
97 .macro OP_REGS op, reg_width, start_reg, end_reg, base_reg, base_reg_offset=0, skip=0
98 	.set i, \start_reg
99 	.rept (\end_reg - \start_reg + 1)
100 	\op	i, (\reg_width * (i - \skip) + \base_reg_offset)(\base_reg)
101 	.set i, i + 1
102 	.endr
103 .endm
104 
105 #endif /* _SELFTESTS_POWERPC_BASIC_ASM_H */
106