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)  \
24	((STACK_FRAME_PARAM(_num_params)) + ((_var_num)*8))
25#else
26#define STACK_FRAME_MIN_SIZE 112
27#define STACK_FRAME_TOC_POS  40
28#define __STACK_FRAME_PARAM(i)  (48 + ((i)*8))
29
30/*
31 * Caveat: if a function passed more than 8 doublewords, the caller will have
32 * made more space... which would render the 112 incorrect.
33 */
34#define __STACK_FRAME_LOCAL(_num_params, _var_num)  \
35	(112 + ((_var_num)*8))
36#endif
37
38/* Parameter x saved to the stack */
39#define STACK_FRAME_PARAM(var)    __STACK_FRAME_PARAM(var)
40
41/* Local variable x saved to the stack after x parameters */
42#define STACK_FRAME_LOCAL(num_params, var)    \
43	__STACK_FRAME_LOCAL(num_params, var)
44#define STACK_FRAME_LR_POS   16
45#define STACK_FRAME_CR_POS   8
46
47/*
48 * It is very important to note here that _extra is the extra amount of
49 * stack space needed. This space can be accessed using STACK_FRAME_PARAM()
50 * or STACK_FRAME_LOCAL() macros.
51 *
52 * r1 and r2 are not defined in ppc-asm.h (instead they are defined as sp
53 * and toc). Kernel programmers tend to prefer rX even for r1 and r2, hence
54 * %1 and %r2. r0 is defined in ppc-asm.h and therefore %r0 gets
55 * preprocessed incorrectly, hence r0.
56 */
57#define PUSH_BASIC_STACK(_extra) \
58	mflr	r0; \
59	std	r0, STACK_FRAME_LR_POS(%r1); \
60	stdu	%r1, -(_extra + STACK_FRAME_MIN_SIZE)(%r1); \
61	mfcr	r0; \
62	stw	r0, STACK_FRAME_CR_POS(%r1); \
63	std	%r2, STACK_FRAME_TOC_POS(%r1);
64
65#define POP_BASIC_STACK(_extra) \
66	ld	%r2, STACK_FRAME_TOC_POS(%r1); \
67	lwz	r0, STACK_FRAME_CR_POS(%r1); \
68	mtcr	r0; \
69	addi	%r1, %r1, (_extra + STACK_FRAME_MIN_SIZE); \
70	ld	r0, STACK_FRAME_LR_POS(%r1); \
71	mtlr	r0;
72
73#endif /* _SELFTESTS_POWERPC_BASIC_ASM_H */