x86/paravirt: Remove no longer needed 32-bit pvops cruft

PVOP_VCALL4() is only used for Xen PV, while PVOP_CALL4() isn't used
at all. Keep PVOP_CALL4() for 64 bits due to symmetry reasons.

This allows to remove the 32-bit definitions of those macros leading
to a substantial simplification of the paravirt macros, as those were
the only ones needing non-empty "pre" and "post" parameters.

PVOP_CALLEE2() and PVOP_VCALLEE2() are used nowhere, so remove them.

Another no longer needed case is special handling of return types
larger than unsigned long. Replace that with a BUILD_BUG_ON().

DISABLE_INTERRUPTS() is used in 32-bit code only, so it can just be
replaced by cli.

INTERRUPT_RETURN in 32-bit code can be replaced by iret.

ENABLE_INTERRUPTS is used nowhere, so it can be removed.

Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20210311142319.4723-10-jgross@suse.com

1 files changed, 32 insertions, 80 deletions

diff --git a/arch/x86/include/asm/paravirt_types.h b/arch/x86/include/asm/paravirt_types.h
index 1fff349e4792..42f9eef84131 100644
--- a/arch/x86/include/asm/paravirt_types.h
+++ b/arch/x86/include/asm/paravirt_types.h
@@ -470,55 +470,34 @@ int paravirt_disable_iospace(void);
 	})
 
 
-#define ____PVOP_CALL(rettype, op, clbr, call_clbr, extra_clbr,		\
-		      pre, post, ...)					\
+#define ____PVOP_CALL(rettype, op, clbr, call_clbr, extra_clbr, ...)	\
 	({								\
-		rettype __ret;						\
 		PVOP_CALL_ARGS;						\
 		PVOP_TEST_NULL(op);					\
-		/* This is 32-bit specific, but is okay in 64-bit */	\
-		/* since this condition will never hold */		\
-		if (sizeof(rettype) > sizeof(unsigned long)) {		\
-			asm volatile(pre				\
-				     paravirt_alt(PARAVIRT_CALL)	\
-				     post				\
-				     : call_clbr, ASM_CALL_CONSTRAINT	\
-				     : paravirt_type(op),		\
-				       paravirt_clobber(clbr),		\
-				       ##__VA_ARGS__			\
-				     : "memory", "cc" extra_clbr);	\
-			__ret = (rettype)((((u64)__edx) << 32) | __eax); \
-		} else {						\
-			asm volatile(pre				\
-				     paravirt_alt(PARAVIRT_CALL)	\
-				     post				\
-				     : call_clbr, ASM_CALL_CONSTRAINT	\
-				     : paravirt_type(op),		\
-				       paravirt_clobber(clbr),		\
-				       ##__VA_ARGS__			\
-				     : "memory", "cc" extra_clbr);	\
-			__ret = (rettype)(__eax & PVOP_RETMASK(rettype));	\
-		}							\
-		__ret;							\
+		BUILD_BUG_ON(sizeof(rettype) > sizeof(unsigned long));	\
+		asm volatile(paravirt_alt(PARAVIRT_CALL)		\
+			     : call_clbr, ASM_CALL_CONSTRAINT		\
+			     : paravirt_type(op),			\
+			       paravirt_clobber(clbr),			\
+			       ##__VA_ARGS__				\
+			     : "memory", "cc" extra_clbr);		\
+		(rettype)(__eax & PVOP_RETMASK(rettype));		\
 	})
 
-#define __PVOP_CALL(rettype, op, pre, post, ...)			\
+#define __PVOP_CALL(rettype, op, ...)					\
 	____PVOP_CALL(rettype, op, CLBR_ANY, PVOP_CALL_CLOBBERS,	\
-		      EXTRA_CLOBBERS, pre, post, ##__VA_ARGS__)
+		      EXTRA_CLOBBERS, ##__VA_ARGS__)
 
-#define __PVOP_CALLEESAVE(rettype, op, pre, post, ...)			\
+#define __PVOP_CALLEESAVE(rettype, op, ...)				\
 	____PVOP_CALL(rettype, op.func, CLBR_RET_REG,			\
-		      PVOP_CALLEE_CLOBBERS, ,				\
-		      pre, post, ##__VA_ARGS__)
+		      PVOP_CALLEE_CLOBBERS, , ##__VA_ARGS__)
 
 
-#define ____PVOP_VCALL(op, clbr, call_clbr, extra_clbr, pre, post, ...)	\
+#define ____PVOP_VCALL(op, clbr, call_clbr, extra_clbr, ...)		\
 	({								\
 		PVOP_VCALL_ARGS;					\
 		PVOP_TEST_NULL(op);					\
-		asm volatile(pre					\
-			     paravirt_alt(PARAVIRT_CALL)		\
-			     post					\
+		asm volatile(paravirt_alt(PARAVIRT_CALL)		\
 			     : call_clbr, ASM_CALL_CONSTRAINT		\
 			     : paravirt_type(op),			\
 			       paravirt_clobber(clbr),			\
@@ -526,84 +505,57 @@ int paravirt_disable_iospace(void);
 			     : "memory", "cc" extra_clbr);		\
 	})
 
-#define __PVOP_VCALL(op, pre, post, ...)				\
+#define __PVOP_VCALL(op, ...)						\
 	____PVOP_VCALL(op, CLBR_ANY, PVOP_VCALL_CLOBBERS,		\
-		       VEXTRA_CLOBBERS,					\
-		       pre, post, ##__VA_ARGS__)
+		       VEXTRA_CLOBBERS, ##__VA_ARGS__)
 
-#define __PVOP_VCALLEESAVE(op, pre, post, ...)				\
+#define __PVOP_VCALLEESAVE(op, ...)					\
 	____PVOP_VCALL(op.func, CLBR_RET_REG,				\
-		      PVOP_VCALLEE_CLOBBERS, ,				\
-		      pre, post, ##__VA_ARGS__)
+		      PVOP_VCALLEE_CLOBBERS, , ##__VA_ARGS__)
 
 
 
 #define PVOP_CALL0(rettype, op)						\
-	__PVOP_CALL(rettype, op, "", "")
+	__PVOP_CALL(rettype, op)
 #define PVOP_VCALL0(op)							\
-	__PVOP_VCALL(op, "", "")
+	__PVOP_VCALL(op)
 
 #define PVOP_CALLEE0(rettype, op)					\
-	__PVOP_CALLEESAVE(rettype, op, "", "")
+	__PVOP_CALLEESAVE(rettype, op)
 #define PVOP_VCALLEE0(op)						\
-	__PVOP_VCALLEESAVE(op, "", "")
+	__PVOP_VCALLEESAVE(op)
 
 
 #define PVOP_CALL1(rettype, op, arg1)					\
-	__PVOP_CALL(rettype, op, "", "", PVOP_CALL_ARG1(arg1))
+	__PVOP_CALL(rettype, op, PVOP_CALL_ARG1(arg1))
 #define PVOP_VCALL1(op, arg1)						\
-	__PVOP_VCALL(op, "", "", PVOP_CALL_ARG1(arg1))
+	__PVOP_VCALL(op, PVOP_CALL_ARG1(arg1))
 
 #define PVOP_CALLEE1(rettype, op, arg1)					\
-	__PVOP_CALLEESAVE(rettype, op, "", "", PVOP_CALL_ARG1(arg1))
+	__PVOP_CALLEESAVE(rettype, op, PVOP_CALL_ARG1(arg1))
 #define PVOP_VCALLEE1(op, arg1)						\
-	__PVOP_VCALLEESAVE(op, "", "", PVOP_CALL_ARG1(arg1))
+	__PVOP_VCALLEESAVE(op, PVOP_CALL_ARG1(arg1))
 
 
 #define PVOP_CALL2(rettype, op, arg1, arg2)				\
-	__PVOP_CALL(rettype, op, "", "", PVOP_CALL_ARG1(arg1),		\
-		    PVOP_CALL_ARG2(arg2))
+	__PVOP_CALL(rettype, op, PVOP_CALL_ARG1(arg1), PVOP_CALL_ARG2(arg2))
 #define PVOP_VCALL2(op, arg1, arg2)					\
-	__PVOP_VCALL(op, "", "", PVOP_CALL_ARG1(arg1),			\
-		     PVOP_CALL_ARG2(arg2))
-
-#define PVOP_CALLEE2(rettype, op, arg1, arg2)				\
-	__PVOP_CALLEESAVE(rettype, op, "", "", PVOP_CALL_ARG1(arg1),	\
-			  PVOP_CALL_ARG2(arg2))
-#define PVOP_VCALLEE2(op, arg1, arg2)					\
-	__PVOP_VCALLEESAVE(op, "", "", PVOP_CALL_ARG1(arg1),		\
-			   PVOP_CALL_ARG2(arg2))
-
+	__PVOP_VCALL(op, PVOP_CALL_ARG1(arg1), PVOP_CALL_ARG2(arg2))
 
 #define PVOP_CALL3(rettype, op, arg1, arg2, arg3)			\
-	__PVOP_CALL(rettype, op, "", "", PVOP_CALL_ARG1(arg1),		\
+	__PVOP_CALL(rettype, op, PVOP_CALL_ARG1(arg1),			\
 		    PVOP_CALL_ARG2(arg2), PVOP_CALL_ARG3(arg3))
 #define PVOP_VCALL3(op, arg1, arg2, arg3)				\
-	__PVOP_VCALL(op, "", "", PVOP_CALL_ARG1(arg1),			\
+	__PVOP_VCALL(op, PVOP_CALL_ARG1(arg1),				\
 		     PVOP_CALL_ARG2(arg2), PVOP_CALL_ARG3(arg3))
 
-/* This is the only difference in x86_64. We can make it much simpler */
-#ifdef CONFIG_X86_32
 #define PVOP_CALL4(rettype, op, arg1, arg2, arg3, arg4)			\
 	__PVOP_CALL(rettype, op,					\
-		    "push %[_arg4];", "lea 4(%%esp),%%esp;",		\
-		    PVOP_CALL_ARG1(arg1), PVOP_CALL_ARG2(arg2),		\
-		    PVOP_CALL_ARG3(arg3), [_arg4] "mr" ((u32)(arg4)))
-#define PVOP_VCALL4(op, arg1, arg2, arg3, arg4)				\
-	__PVOP_VCALL(op,						\
-		    "push %[_arg4];", "lea 4(%%esp),%%esp;",		\
-		    "0" ((u32)(arg1)), "1" ((u32)(arg2)),		\
-		    "2" ((u32)(arg3)), [_arg4] "mr" ((u32)(arg4)))
-#else
-#define PVOP_CALL4(rettype, op, arg1, arg2, arg3, arg4)			\
-	__PVOP_CALL(rettype, op, "", "",				\
 		    PVOP_CALL_ARG1(arg1), PVOP_CALL_ARG2(arg2),		\
 		    PVOP_CALL_ARG3(arg3), PVOP_CALL_ARG4(arg4))
 #define PVOP_VCALL4(op, arg1, arg2, arg3, arg4)				\
-	__PVOP_VCALL(op, "", "",					\
-		     PVOP_CALL_ARG1(arg1), PVOP_CALL_ARG2(arg2),	\
+	__PVOP_VCALL(op, PVOP_CALL_ARG1(arg1), PVOP_CALL_ARG2(arg2),	\
 		     PVOP_CALL_ARG3(arg3), PVOP_CALL_ARG4(arg4))
-#endif
 
 /* Lazy mode for batching updates / context switch */
 enum paravirt_lazy_mode {