[PATCH 14/20] x86/tdx: Add macros to generate TDCALL wrappers

[Kirill A. Shutemov]

Introduce a set of macros that allow to generate wrappers for TDCALL
leafs.

There are three macros differentiated by number of return parameters.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
---
 arch/x86/include/asm/shared/tdx.h | 58 +++++++++++++++++++++++++++++++
 1 file changed, 58 insertions(+)

diff --git a/arch/x86/include/asm/shared/tdx.h b/arch/x86/include/asm/shared/tdx.h
index 46c299dc9cf0..70190ebc63ca 100644
--- a/arch/x86/include/asm/shared/tdx.h
+++ b/arch/x86/include/asm/shared/tdx.h
@@ -80,6 +80,64 @@
 
 #include <linux/compiler_attributes.h>
 
+#define TDCALL	".byte	0x66,0x0f,0x01,0xcc\n\t"
+
+#define TDCALL_0(reason, in_rcx, in_rdx, in_r8, in_r9)				\
+({										\
+	long __ret;								\
+										\
+	asm(									\
+		"movq	%[r8_in], %%r8\n\t"					\
+		"movq	%[r9_in], %%r9\n\t"					\
+		TDCALL								\
+		: "=a" (__ret), ASM_CALL_CONSTRAINT				\
+		: "a" (reason), "c" (in_rcx), "d" (in_rdx),			\
+		  [r8_in] "rm" ((u64)in_r8), [r9_in] "rm" ((u64)in_r9)		\
+		: "r8", "r9"							\
+	);									\
+	__ret;									\
+})
+
+#define TDCALL_1(reason, in_rcx, in_rdx, in_r8, in_r9, out_r8)			\
+({										\
+	long __ret;								\
+										\
+	asm(									\
+		"movq	%[r8_in], %%r8\n\t"					\
+		"movq	%[r9_in], %%r9\n\t"					\
+		TDCALL								\
+		"movq	%%r8, %[r8_out]\n\t"					\
+		: "=a" (__ret), ASM_CALL_CONSTRAINT, [r8_out] "=rm" (out_r8)	\
+		: "a" (reason), "c" (in_rcx), "d" (in_rdx),			\
+		  [r8_in] "rm" ((u64)in_r8), [r9_in] "rm" ((u64)in_r9)		\
+		: "r8", "r9"							\
+	);									\
+	__ret;									\
+})
+
+#define TDCALL_5(reason, in_rcx, in_rdx, in_r8, in_r9,				\
+		 out_rcx, out_rdx, out_r8, out_r9, out_r10)			\
+({										\
+	long __ret;								\
+										\
+	asm(									\
+		"movq	%[r8_in], %%r8\n\t"					\
+		"movq	%[r9_in], %%r9\n\t"					\
+		TDCALL								\
+		"movq	%%r8, %[r8_out]\n\t"					\
+		"movq	%%r9, %[r9_out]\n\t"					\
+		"movq	%%r10, %[r10_out]\n\t"					\
+		: "=a" (__ret), ASM_CALL_CONSTRAINT,				\
+		  "=c" (out_rcx), "=d" (out_rdx),				\
+		  [r8_out] "=rm" (out_r8), [r9_out] "=rm" (out_r9),		\
+		  [r10_out] "=rm" (out_r10)					\
+		: "a" (reason), "c" (in_rcx), "d" (in_rdx),			\
+		  [r8_in] "rm" ((u64)in_r8), [r9_in] "rm" ((u64)in_r9)		\
+		: "r8", "r9", "r10"						\
+	);									\
+	__ret;									\
+})
+
 #define TDVMCALL_0(reason, in_r12, in_r13, in_r14, in_r15)			\
 ({										\
 	long __ret;								\
-- 
2.43.0