Commit 0b8d366a authored by Juergen Gross's avatar Juergen Gross Committed by Borislav Petkov
Browse files

x86/paravirt: Simplify paravirt macros 



The central pvops call macros ____PVOP_CALL() and ____PVOP_VCALL() are
looking very similar now.

The main differences are using PVOP_VCALL_ARGS or PVOP_CALL_ARGS, which
are identical, and the return value handling.

So drop PVOP_VCALL_ARGS and instead of ____PVOP_VCALL() just use
(void)____PVOP_CALL(long, ...).

Note that it isn't easily possible to just redefine ____PVOP_VCALL()
to use ____PVOP_CALL() instead, as this would require further hiding of
commas in macro parameters.

Signed-off-by: default avatarJuergen Gross <jgross@suse.com>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Acked-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20210311142319.4723-11-jgross@suse.com
parent 33634e42

arch/x86/include/asm/paravirt_types.h

+12 −29
Original line number Diff line number Diff line
@@ -408,11 +408,9 @@ int paravirt_disable_iospace(void); 
 * makes sure the incoming and outgoing types are always correct.

 */

#ifdef CONFIG_X86_32

#define PVOP_VCALL_ARGS							\

#define PVOP_CALL_ARGS							\

	unsigned long __eax = __eax, __edx = __edx, __ecx = __ecx;



#define PVOP_CALL_ARGS			PVOP_VCALL_ARGS



#define PVOP_CALL_ARG1(x)		"a" ((unsigned long)(x))

#define PVOP_CALL_ARG2(x)		"d" ((unsigned long)(x))

#define PVOP_CALL_ARG3(x)		"c" ((unsigned long)(x))
@@ -428,12 +426,10 @@ int paravirt_disable_iospace(void); 
#define VEXTRA_CLOBBERS

#else  /* CONFIG_X86_64 */

/* [re]ax isn't an arg, but the return val */

#define PVOP_VCALL_ARGS						\

#define PVOP_CALL_ARGS						\

	unsigned long __edi = __edi, __esi = __esi,		\

		__edx = __edx, __ecx = __ecx, __eax = __eax;



#define PVOP_CALL_ARGS		PVOP_VCALL_ARGS



#define PVOP_CALL_ARG1(x)		"D" ((unsigned long)(x))

#define PVOP_CALL_ARG2(x)		"S" ((unsigned long)(x))

#define PVOP_CALL_ARG3(x)		"d" ((unsigned long)(x))
@@ -458,59 +454,46 @@ int paravirt_disable_iospace(void); 
#define PVOP_TEST_NULL(op)	((void)pv_ops.op)

#endif



#define PVOP_RETMASK(rettype)						\

#define PVOP_RETVAL(rettype)						\

	({	unsigned long __mask = ~0UL;				\

		BUILD_BUG_ON(sizeof(rettype) > sizeof(unsigned long));	\

		switch (sizeof(rettype)) {				\

		case 1: __mask =       0xffUL; break;			\

		case 2: __mask =     0xffffUL; break;			\

		case 4: __mask = 0xffffffffUL; break;			\

		default: break;						\

		}							\

		__mask;							\

		__mask & __eax;						\

	})





#define ____PVOP_CALL(rettype, op, clbr, call_clbr, extra_clbr, ...)	\

#define ____PVOP_CALL(ret, op, clbr, call_clbr, extra_clbr, ...)	\

	({								\

		PVOP_CALL_ARGS;						\

		PVOP_TEST_NULL(op);					\

		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));		\

		ret;							\

	})



#define __PVOP_CALL(rettype, op, ...)					\

	____PVOP_CALL(rettype, op, CLBR_ANY, PVOP_CALL_CLOBBERS,	\

		      EXTRA_CLOBBERS, ##__VA_ARGS__)

	____PVOP_CALL(PVOP_RETVAL(rettype), op, CLBR_ANY,		\

		      PVOP_CALL_CLOBBERS, EXTRA_CLOBBERS, ##__VA_ARGS__)



#define __PVOP_CALLEESAVE(rettype, op, ...)				\

	____PVOP_CALL(rettype, op.func, CLBR_RET_REG,			\

	____PVOP_CALL(PVOP_RETVAL(rettype), op.func, CLBR_RET_REG,	\

		      PVOP_CALLEE_CLOBBERS, , ##__VA_ARGS__)





#define ____PVOP_VCALL(op, clbr, call_clbr, extra_clbr, ...)		\

	({								\

		PVOP_VCALL_ARGS;					\

		PVOP_TEST_NULL(op);					\

		asm volatile(paravirt_alt(PARAVIRT_CALL)		\

			     : call_clbr, ASM_CALL_CONSTRAINT		\

			     : paravirt_type(op),			\

			       paravirt_clobber(clbr),			\

			       ##__VA_ARGS__				\

			     : "memory", "cc" extra_clbr);		\

	})



#define __PVOP_VCALL(op, ...)						\

	____PVOP_VCALL(op, CLBR_ANY, PVOP_VCALL_CLOBBERS,		\

	(void)____PVOP_CALL(, op, CLBR_ANY, PVOP_VCALL_CLOBBERS,	\

		       VEXTRA_CLOBBERS, ##__VA_ARGS__)



#define __PVOP_VCALLEESAVE(op, ...)					\

	____PVOP_VCALL(op.func, CLBR_RET_REG,				\

	(void)____PVOP_CALL(, op.func, CLBR_RET_REG,			\

		      PVOP_VCALLEE_CLOBBERS, , ##__VA_ARGS__)