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