From 01127f1ead4cef75e2b9b309e0ea95418ccd53bd Mon Sep 17 00:00:00 2001 From: Cyril Bur Date: Mon, 29 Feb 2016 17:53:43 +1100 Subject: selftests/powerpc: Test the preservation of FPU and VMX regs across syscall Test that the non volatile floating point and Altivec registers get correctly preserved across the fork() syscall. fork() works nicely for this purpose, the registers should be the same for both parent and child Signed-off-by: Cyril Bur [mpe: Add include guards to basic_asm.h, minor formatting] Signed-off-by: Michael Ellerman --- tools/testing/selftests/powerpc/basic_asm.h | 70 +++++++++++++++++++++++++++++ 1 file changed, 70 insertions(+) create mode 100644 tools/testing/selftests/powerpc/basic_asm.h (limited to 'tools/testing/selftests/powerpc/basic_asm.h') diff --git a/tools/testing/selftests/powerpc/basic_asm.h b/tools/testing/selftests/powerpc/basic_asm.h new file mode 100644 index 000000000000..3349a0704d1a --- /dev/null +++ b/tools/testing/selftests/powerpc/basic_asm.h @@ -0,0 +1,70 @@ +#ifndef _SELFTESTS_POWERPC_BASIC_ASM_H +#define _SELFTESTS_POWERPC_BASIC_ASM_H + +#include +#include + +#define LOAD_REG_IMMEDIATE(reg,expr) \ + lis reg,(expr)@highest; \ + ori reg,reg,(expr)@higher; \ + rldicr reg,reg,32,31; \ + oris reg,reg,(expr)@high; \ + ori reg,reg,(expr)@l; + +/* + * Note: These macros assume that variables being stored on the stack are + * doublewords, while this is usually the case it may not always be the + * case for each use case. + */ +#if defined(_CALL_ELF) && _CALL_ELF == 2 +#define STACK_FRAME_MIN_SIZE 32 +#define STACK_FRAME_TOC_POS 24 +#define __STACK_FRAME_PARAM(_param) (32 + ((_param)*8)) +#define __STACK_FRAME_LOCAL(_num_params,_var_num) ((STACK_FRAME_PARAM(_num_params)) + ((_var_num)*8)) +#else +#define STACK_FRAME_MIN_SIZE 112 +#define STACK_FRAME_TOC_POS 40 +#define __STACK_FRAME_PARAM(i) (48 + ((i)*8)) + +/* + * Caveat: if a function passed more than 8 doublewords, the caller will have + * made more space... which would render the 112 incorrect. + */ +#define __STACK_FRAME_LOCAL(_num_params,_var_num) (112 + ((_var_num)*8)) +#endif + +/* Parameter x saved to the stack */ +#define STACK_FRAME_PARAM(var) __STACK_FRAME_PARAM(var) + +/* Local variable x saved to the stack after x parameters */ +#define STACK_FRAME_LOCAL(num_params,var) __STACK_FRAME_LOCAL(num_params,var) +#define STACK_FRAME_LR_POS 16 +#define STACK_FRAME_CR_POS 8 + +/* + * It is very important to note here that _extra is the extra amount of + * stack space needed. This space can be accessed using STACK_FRAME_PARAM() + * or STACK_FRAME_LOCAL() macros. + * + * r1 and r2 are not defined in ppc-asm.h (instead they are defined as sp + * and toc). Kernel programmers tend to prefer rX even for r1 and r2, hence + * %1 and %r2. r0 is defined in ppc-asm.h and therefore %r0 gets + * preprocessed incorrectly, hence r0. + */ +#define PUSH_BASIC_STACK(_extra) \ + mflr r0; \ + std r0,STACK_FRAME_LR_POS(%r1); \ + stdu %r1,-(_extra + STACK_FRAME_MIN_SIZE)(%r1); \ + mfcr r0; \ + stw r0,STACK_FRAME_CR_POS(%r1); \ + std %r2,STACK_FRAME_TOC_POS(%r1); + +#define POP_BASIC_STACK(_extra) \ + ld %r2,STACK_FRAME_TOC_POS(%r1); \ + lwz r0,STACK_FRAME_CR_POS(%r1); \ + mtcr r0; \ + addi %r1,%r1,(_extra + STACK_FRAME_MIN_SIZE); \ + ld r0,STACK_FRAME_LR_POS(%r1); \ + mtlr r0; + +#endif /* _SELFTESTS_POWERPC_BASIC_ASM_H */ -- cgit v1.2.3-59-g8ed1b