xref: /OK3568_Linux_fs/kernel/tools/testing/selftests/powerpc/include/basic_asm.h (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-2.0 */
2*4882a593Smuzhiyun #ifndef _SELFTESTS_POWERPC_BASIC_ASM_H
3*4882a593Smuzhiyun #define _SELFTESTS_POWERPC_BASIC_ASM_H
4*4882a593Smuzhiyun 
5*4882a593Smuzhiyun #include <ppc-asm.h>
6*4882a593Smuzhiyun #include <asm/unistd.h>
7*4882a593Smuzhiyun 
8*4882a593Smuzhiyun #define LOAD_REG_IMMEDIATE(reg, expr) \
9*4882a593Smuzhiyun 	lis	reg, (expr)@highest;	\
10*4882a593Smuzhiyun 	ori	reg, reg, (expr)@higher;	\
11*4882a593Smuzhiyun 	rldicr	reg, reg, 32, 31;	\
12*4882a593Smuzhiyun 	oris	reg, reg, (expr)@high;	\
13*4882a593Smuzhiyun 	ori	reg, reg, (expr)@l;
14*4882a593Smuzhiyun 
15*4882a593Smuzhiyun /*
16*4882a593Smuzhiyun  * Note: These macros assume that variables being stored on the stack are
17*4882a593Smuzhiyun  * doublewords, while this is usually the case it may not always be the
18*4882a593Smuzhiyun  * case for each use case.
19*4882a593Smuzhiyun  */
20*4882a593Smuzhiyun #if defined(_CALL_ELF) && _CALL_ELF == 2
21*4882a593Smuzhiyun #define STACK_FRAME_MIN_SIZE 32
22*4882a593Smuzhiyun #define STACK_FRAME_TOC_POS  24
23*4882a593Smuzhiyun #define __STACK_FRAME_PARAM(_param)  (32 + ((_param)*8))
24*4882a593Smuzhiyun #define __STACK_FRAME_LOCAL(_num_params, _var_num)  \
25*4882a593Smuzhiyun 	((STACK_FRAME_PARAM(_num_params)) + ((_var_num)*8))
26*4882a593Smuzhiyun #else
27*4882a593Smuzhiyun #define STACK_FRAME_MIN_SIZE 112
28*4882a593Smuzhiyun #define STACK_FRAME_TOC_POS  40
29*4882a593Smuzhiyun #define __STACK_FRAME_PARAM(i)  (48 + ((i)*8))
30*4882a593Smuzhiyun 
31*4882a593Smuzhiyun /*
32*4882a593Smuzhiyun  * Caveat: if a function passed more than 8 doublewords, the caller will have
33*4882a593Smuzhiyun  * made more space... which would render the 112 incorrect.
34*4882a593Smuzhiyun  */
35*4882a593Smuzhiyun #define __STACK_FRAME_LOCAL(_num_params, _var_num)  \
36*4882a593Smuzhiyun 	(112 + ((_var_num)*8))
37*4882a593Smuzhiyun #endif
38*4882a593Smuzhiyun 
39*4882a593Smuzhiyun /* Parameter x saved to the stack */
40*4882a593Smuzhiyun #define STACK_FRAME_PARAM(var)    __STACK_FRAME_PARAM(var)
41*4882a593Smuzhiyun 
42*4882a593Smuzhiyun /* Local variable x saved to the stack after x parameters */
43*4882a593Smuzhiyun #define STACK_FRAME_LOCAL(num_params, var)    \
44*4882a593Smuzhiyun 	__STACK_FRAME_LOCAL(num_params, var)
45*4882a593Smuzhiyun #define STACK_FRAME_LR_POS   16
46*4882a593Smuzhiyun #define STACK_FRAME_CR_POS   8
47*4882a593Smuzhiyun 
48*4882a593Smuzhiyun /*
49*4882a593Smuzhiyun  * It is very important to note here that _extra is the extra amount of
50*4882a593Smuzhiyun  * stack space needed. This space can be accessed using STACK_FRAME_PARAM()
51*4882a593Smuzhiyun  * or STACK_FRAME_LOCAL() macros.
52*4882a593Smuzhiyun  *
53*4882a593Smuzhiyun  * r1 and r2 are not defined in ppc-asm.h (instead they are defined as sp
54*4882a593Smuzhiyun  * and toc). Kernel programmers tend to prefer rX even for r1 and r2, hence
55*4882a593Smuzhiyun  * %1 and %r2. r0 is defined in ppc-asm.h and therefore %r0 gets
56*4882a593Smuzhiyun  * preprocessed incorrectly, hence r0.
57*4882a593Smuzhiyun  */
58*4882a593Smuzhiyun #define PUSH_BASIC_STACK(_extra) \
59*4882a593Smuzhiyun 	mflr	r0; \
60*4882a593Smuzhiyun 	std	r0, STACK_FRAME_LR_POS(%r1); \
61*4882a593Smuzhiyun 	stdu	%r1, -(_extra + STACK_FRAME_MIN_SIZE)(%r1); \
62*4882a593Smuzhiyun 	mfcr	r0; \
63*4882a593Smuzhiyun 	stw	r0, STACK_FRAME_CR_POS(%r1); \
64*4882a593Smuzhiyun 	std	%r2, STACK_FRAME_TOC_POS(%r1);
65*4882a593Smuzhiyun 
66*4882a593Smuzhiyun #define POP_BASIC_STACK(_extra) \
67*4882a593Smuzhiyun 	ld	%r2, STACK_FRAME_TOC_POS(%r1); \
68*4882a593Smuzhiyun 	lwz	r0, STACK_FRAME_CR_POS(%r1); \
69*4882a593Smuzhiyun 	mtcr	r0; \
70*4882a593Smuzhiyun 	addi	%r1, %r1, (_extra + STACK_FRAME_MIN_SIZE); \
71*4882a593Smuzhiyun 	ld	r0, STACK_FRAME_LR_POS(%r1); \
72*4882a593Smuzhiyun 	mtlr	r0;
73*4882a593Smuzhiyun 
74*4882a593Smuzhiyun #endif /* _SELFTESTS_POWERPC_BASIC_ASM_H */
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