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-rw-r--r--tools/testing/selftests/powerpc/include/basic_asm.h74
1 files changed, 74 insertions, 0 deletions
diff --git a/tools/testing/selftests/powerpc/include/basic_asm.h b/tools/testing/selftests/powerpc/include/basic_asm.h
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+++ b/tools/testing/selftests/powerpc/include/basic_asm.h
@@ -0,0 +1,74 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _SELFTESTS_POWERPC_BASIC_ASM_H
+#define _SELFTESTS_POWERPC_BASIC_ASM_H
+
+#include <ppc-asm.h>
+#include <asm/unistd.h>
+
+#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 */