basic_asm.h (2382B)
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#define LOAD_REG_IMMEDIATE(reg, expr) \ 9 lis reg, (expr)@highest; \ 10 ori reg, reg, (expr)@higher; \ 11 rldicr reg, reg, 32, 31; \ 12 oris reg, reg, (expr)@high; \ 13 ori reg, reg, (expr)@l; 14 15/* 16 * Note: These macros assume that variables being stored on the stack are 17 * doublewords, while this is usually the case it may not always be the 18 * case for each use case. 19 */ 20#if defined(_CALL_ELF) && _CALL_ELF == 2 21#define STACK_FRAME_MIN_SIZE 32 22#define STACK_FRAME_TOC_POS 24 23#define __STACK_FRAME_PARAM(_param) (32 + ((_param)*8)) 24#define __STACK_FRAME_LOCAL(_num_params, _var_num) \ 25 ((STACK_FRAME_PARAM(_num_params)) + ((_var_num)*8)) 26#else 27#define STACK_FRAME_MIN_SIZE 112 28#define STACK_FRAME_TOC_POS 40 29#define __STACK_FRAME_PARAM(i) (48 + ((i)*8)) 30 31/* 32 * Caveat: if a function passed more than 8 doublewords, the caller will have 33 * made more space... which would render the 112 incorrect. 34 */ 35#define __STACK_FRAME_LOCAL(_num_params, _var_num) \ 36 (112 + ((_var_num)*8)) 37#endif 38 39/* Parameter x saved to the stack */ 40#define STACK_FRAME_PARAM(var) __STACK_FRAME_PARAM(var) 41 42/* Local variable x saved to the stack after x parameters */ 43#define STACK_FRAME_LOCAL(num_params, var) \ 44 __STACK_FRAME_LOCAL(num_params, var) 45#define STACK_FRAME_LR_POS 16 46#define STACK_FRAME_CR_POS 8 47 48/* 49 * It is very important to note here that _extra is the extra amount of 50 * stack space needed. This space can be accessed using STACK_FRAME_PARAM() 51 * or STACK_FRAME_LOCAL() macros. 52 * 53 * r1 and r2 are not defined in ppc-asm.h (instead they are defined as sp 54 * and toc). Kernel programmers tend to prefer rX even for r1 and r2, hence 55 * %1 and %r2. r0 is defined in ppc-asm.h and therefore %r0 gets 56 * preprocessed incorrectly, hence r0. 57 */ 58#define PUSH_BASIC_STACK(_extra) \ 59 mflr r0; \ 60 std r0, STACK_FRAME_LR_POS(%r1); \ 61 stdu %r1, -(_extra + STACK_FRAME_MIN_SIZE)(%r1); \ 62 mfcr r0; \ 63 stw r0, STACK_FRAME_CR_POS(%r1); \ 64 std %r2, STACK_FRAME_TOC_POS(%r1); 65 66#define POP_BASIC_STACK(_extra) \ 67 ld %r2, STACK_FRAME_TOC_POS(%r1); \ 68 lwz r0, STACK_FRAME_CR_POS(%r1); \ 69 mtcr r0; \ 70 addi %r1, %r1, (_extra + STACK_FRAME_MIN_SIZE); \ 71 ld r0, STACK_FRAME_LR_POS(%r1); \ 72 mtlr r0; 73 74#endif /* _SELFTESTS_POWERPC_BASIC_ASM_H */