tools/testing/selftests/powerpc/basic_asm.h

   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 */