linux/arch/x86/xen/xen-asm_64.S
Andy Lutomirski aac82d3191 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>
2015-04-22 08:07:45 +02:00

144 lines
3.0 KiB
ArmAsm

/*
* Asm versions of Xen pv-ops, suitable for either direct use or
* inlining. The inline versions are the same as the direct-use
* versions, with the pre- and post-amble chopped off.
*
* This code is encoded for size rather than absolute efficiency, with
* a view to being able to inline as much as possible.
*
* We only bother with direct forms (ie, vcpu in pda) of the
* operations here; the indirect forms are better handled in C, since
* they're generally too large to inline anyway.
*/
#include <asm/errno.h>
#include <asm/percpu.h>
#include <asm/processor-flags.h>
#include <asm/segment.h>
#include <xen/interface/xen.h>
#include "xen-asm.h"
ENTRY(xen_adjust_exception_frame)
mov 8+0(%rsp), %rcx
mov 8+8(%rsp), %r11
ret $16
hypercall_iret = hypercall_page + __HYPERVISOR_iret * 32
/*
* Xen64 iret frame:
*
* ss
* rsp
* rflags
* cs
* rip <-- standard iret frame
*
* flags
*
* rcx }
* r11 }<-- pushed by hypercall page
* rsp->rax }
*/
ENTRY(xen_iret)
pushq $0
1: jmp hypercall_iret
ENDPATCH(xen_iret)
RELOC(xen_iret, 1b+1)
ENTRY(xen_sysret64)
/*
* We're already on the usermode stack at this point, but
* still with the kernel gs, so we can easily switch back
*/
movq %rsp, PER_CPU_VAR(rsp_scratch)
movq PER_CPU_VAR(kernel_stack), %rsp
pushq $__USER_DS
pushq PER_CPU_VAR(rsp_scratch)
pushq %r11
pushq $__USER_CS
pushq %rcx
pushq $VGCF_in_syscall
1: jmp hypercall_iret
ENDPATCH(xen_sysret64)
RELOC(xen_sysret64, 1b+1)
ENTRY(xen_sysret32)
/*
* We're already on the usermode stack at this point, but
* still with the kernel gs, so we can easily switch back
*/
movq %rsp, PER_CPU_VAR(rsp_scratch)
movq PER_CPU_VAR(kernel_stack), %rsp
pushq $__USER32_DS
pushq PER_CPU_VAR(rsp_scratch)
pushq %r11
pushq $__USER32_CS
pushq %rcx
pushq $0
1: jmp hypercall_iret
ENDPATCH(xen_sysret32)
RELOC(xen_sysret32, 1b+1)
/*
* Xen handles syscall callbacks much like ordinary exceptions, which
* means we have:
* - kernel gs
* - kernel rsp
* - an iret-like stack frame on the stack (including rcx and r11):
* ss
* rsp
* rflags
* cs
* rip
* r11
* rsp->rcx
*
* In all the entrypoints, we undo all that to make it look like a
* CPU-generated syscall/sysenter and jump to the normal entrypoint.
*/
.macro undo_xen_syscall
mov 0*8(%rsp), %rcx
mov 1*8(%rsp), %r11
mov 5*8(%rsp), %rsp
.endm
/* Normal 64-bit system call target */
ENTRY(xen_syscall_target)
undo_xen_syscall
jmp system_call_after_swapgs
ENDPROC(xen_syscall_target)
#ifdef CONFIG_IA32_EMULATION
/* 32-bit compat syscall target */
ENTRY(xen_syscall32_target)
undo_xen_syscall
jmp ia32_cstar_target
ENDPROC(xen_syscall32_target)
/* 32-bit compat sysenter target */
ENTRY(xen_sysenter_target)
undo_xen_syscall
jmp ia32_sysenter_target
ENDPROC(xen_sysenter_target)
#else /* !CONFIG_IA32_EMULATION */
ENTRY(xen_syscall32_target)
ENTRY(xen_sysenter_target)
lea 16(%rsp), %rsp /* strip %rcx, %r11 */
mov $-ENOSYS, %rax
pushq $0
jmp hypercall_iret
ENDPROC(xen_syscall32_target)
ENDPROC(xen_sysenter_target)
#endif /* CONFIG_IA32_EMULATION */