x86, paravirt, xen: Remove the 64-bit ->irq_enable_sysexit() pvop

We don't use irq_enable_sysexit on 64-bit kernels any more.
Remove all the paravirt and Xen machinery to support it on
64-bit kernels.

Tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Denys Vlasenko <vda.linux@googlemail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/8a03355698fe5b94194e9e7360f19f91c1b2cf1f.1428100853.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

3 files changed, 4 insertions, 17 deletions

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 81665c9f2132..3797b6b31f95 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -1267,10 +1267,11 @@ static const struct pv_cpu_ops xen_cpu_ops __initconst = {
         .read_tscp = native_read_tscp,
 
         .iret = xen_iret,
-        .irq_enable_sysexit = xen_sysexit,
 #ifdef CONFIG_X86_64
         .usergs_sysret32 = xen_sysret32,
         .usergs_sysret64 = xen_sysret64,
+#else
+        .irq_enable_sysexit = xen_sysexit,
 #endif
 
         .load_tr_desc = paravirt_nop,
diff --git a/arch/x86/xen/xen-asm_64.S b/arch/x86/xen/xen-asm_64.S
index 985fc3ee0973..a2cabb8bd6bf 100644
--- a/arch/x86/xen/xen-asm_64.S
+++ b/arch/x86/xen/xen-asm_64.S
@@ -47,22 +47,6 @@ ENTRY(xen_iret)
 ENDPATCH(xen_iret)
 RELOC(xen_iret, 1b+1)
 
-/*
- * sysexit is not used for 64-bit processes, so it's only ever used to
- * return to 32-bit compat userspace.
- */
-ENTRY(xen_sysexit)
-        pushq $__USER32_DS
-        pushq %rcx
-        pushq $X86_EFLAGS_IF
-        pushq $__USER32_CS
-        pushq %rdx
-
-        pushq $0
-1:      jmp hypercall_iret
-ENDPATCH(xen_sysexit)
-RELOC(xen_sysexit, 1b+1)
-
 ENTRY(xen_sysret64)
         /*
          * We're already on the usermode stack at this point, but
diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h
index 9e195c683549..c20fe29e65f4 100644
--- a/arch/x86/xen/xen-ops.h
+++ b/arch/x86/xen/xen-ops.h
@@ -134,7 +134,9 @@ DECL_ASM(void, xen_restore_fl_direct, unsigned long);
 
 /* These are not functions, and cannot be called normally */
 __visible void xen_iret(void);
+#ifdef CONFIG_X86_32
 __visible void xen_sysexit(void);
+#endif
 __visible void xen_sysret32(void);
 __visible void xen_sysret64(void);
 __visible void xen_adjust_exception_frame(void);