Commit 491eccb7 authored by Jeremy Fitzhardinge's avatar Jeremy Fitzhardinge Committed by Ingo Molnar
Browse files

x86/paravirt: define PARA_INDIRECT for indirect asm calls 



On 32-bit it's best to use a %cs: prefix to access memory where the
other segments may not bet set up properly yet.  On 64-bit it's best
to use a rip-relative addressing mode.  Define PARA_INDIRECT() to
abstract this and generate the proper addressing mode in each case.

Signed-off-by: default avatarJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: xen-devel <xen-devel@lists.xensource.com>
Cc: Stephen Tweedie <sct@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 97349135

include/asm-x86/paravirt.h

+15 −13
Original line number Diff line number Diff line
@@ -1455,50 +1455,52 @@ static inline unsigned long __raw_local_irq_save(void) 
#define PV_RESTORE_REGS popq %rdx; popq %rcx; popq %rdi; popq %rax

#define PARA_PATCH(struct, off)        ((PARAVIRT_PATCH_##struct + (off)) / 8)

#define PARA_SITE(ptype, clobbers, ops) _PVSITE(ptype, clobbers, ops, .quad, 8)

#define PARA_INDIRECT(addr)	*addr(%rip)

#else

#define PV_SAVE_REGS   pushl %eax; pushl %edi; pushl %ecx; pushl %edx

#define PV_RESTORE_REGS popl %edx; popl %ecx; popl %edi; popl %eax

#define PARA_PATCH(struct, off)        ((PARAVIRT_PATCH_##struct + (off)) / 4)

#define PARA_SITE(ptype, clobbers, ops) _PVSITE(ptype, clobbers, ops, .long, 4)

#define PARA_INDIRECT(addr)	*%cs:addr

#endif



#define INTERRUPT_RETURN						\

	PARA_SITE(PARA_PATCH(pv_cpu_ops, PV_CPU_iret), CLBR_NONE,	\

		  jmp *%cs:pv_cpu_ops+PV_CPU_iret)

		  jmp PARA_INDIRECT(pv_cpu_ops+PV_CPU_iret))



#define DISABLE_INTERRUPTS(clobbers)					\

	PARA_SITE(PARA_PATCH(pv_irq_ops, PV_IRQ_irq_disable), clobbers, \

		  PV_SAVE_REGS;						\

		  call *%cs:pv_irq_ops+PV_IRQ_irq_disable;		\

		  call PARA_INDIRECT(pv_irq_ops+PV_IRQ_irq_disable);	\

		  PV_RESTORE_REGS;)			\



#define ENABLE_INTERRUPTS(clobbers)					\

	PARA_SITE(PARA_PATCH(pv_irq_ops, PV_IRQ_irq_enable), clobbers,	\

		  PV_SAVE_REGS;						\

		  call *%cs:pv_irq_ops+PV_IRQ_irq_enable;		\

		  call PARA_INDIRECT(pv_irq_ops+PV_IRQ_irq_enable);	\

		  PV_RESTORE_REGS;)



#define ENABLE_INTERRUPTS_SYSCALL_RET					\

	PARA_SITE(PARA_PATCH(pv_cpu_ops, PV_CPU_irq_enable_syscall_ret),\

		  CLBR_NONE,						\

		  jmp *%cs:pv_cpu_ops+PV_CPU_irq_enable_syscall_ret)

		  jmp PARA_INDIRECT(pv_cpu_ops+PV_CPU_irq_enable_syscall_ret))





#ifdef CONFIG_X86_32

#define GET_CR0_INTO_EAX				\

	push %ecx; push %edx;				\

	call *pv_cpu_ops+PV_CPU_read_cr0;	\

	call PARA_INDIRECT(pv_cpu_ops+PV_CPU_read_cr0);	\

	pop %edx; pop %ecx

#else

#define SWAPGS								\

	PARA_SITE(PARA_PATCH(pv_cpu_ops, PV_CPU_swapgs), CLBR_NONE,	\

		  PV_SAVE_REGS;						\

		  call *pv_cpu_ops+PV_CPU_swapgs;			\

		  call PARA_INDIRECT(pv_cpu_ops+PV_CPU_swapgs);		\

		  PV_RESTORE_REGS					\

		 )



#define GET_CR2_INTO_RCX				\

	call *pv_mmu_ops+PV_MMU_read_cr2;	\

	call PARA_INDIRECT(pv_mmu_ops+PV_MMU_read_cr2);	\

	movq %rax, %rcx;				\

	xorq %rax, %rax;

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