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
new file mode 100644
index 000000000..886dc026f
--- /dev/null
+++ 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 */