LXR linux/tools/testing/selftests/powerpc/include/basic

   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 */
  75