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Diffstat (limited to 'arch/x86/xen/xen-asm_64.S')
-rw-r--r--arch/x86/xen/xen-asm_64.S107
1 files changed, 55 insertions, 52 deletions
diff --git a/arch/x86/xen/xen-asm_64.S b/arch/x86/xen/xen-asm_64.S
index d205a283efe..02f496a8dba 100644
--- a/arch/x86/xen/xen-asm_64.S
+++ b/arch/x86/xen/xen-asm_64.S
@@ -1,14 +1,14 @@
/*
- 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.
+ * 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>
@@ -21,25 +21,25 @@
#include "xen-asm.h"
ENTRY(xen_adjust_exception_frame)
- mov 8+0(%rsp),%rcx
- mov 8+8(%rsp),%r11
+ 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 }
+ * 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
@@ -48,8 +48,8 @@ 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.
+ * 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
@@ -64,10 +64,12 @@ ENDPATCH(xen_sysexit)
RELOC(xen_sysexit, 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 */
+ /*
+ * 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(old_rsp)
- movq PER_CPU_VAR(kernel_stack),%rsp
+ movq PER_CPU_VAR(kernel_stack), %rsp
pushq $__USER_DS
pushq PER_CPU_VAR(old_rsp)
@@ -81,8 +83,10 @@ 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 */
+ /*
+ * 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(old_rsp)
movq PER_CPU_VAR(kernel_stack), %rsp
@@ -98,28 +102,27 @@ 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.
+ * 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
+ mov 0*8(%rsp), %rcx
+ mov 1*8(%rsp), %r11
+ mov 5*8(%rsp), %rsp
.endm
/* Normal 64-bit system call target */
@@ -146,7 +149,7 @@ ENDPROC(xen_sysenter_target)
ENTRY(xen_syscall32_target)
ENTRY(xen_sysenter_target)
- lea 16(%rsp), %rsp /* strip %rcx,%r11 */
+ lea 16(%rsp), %rsp /* strip %rcx, %r11 */
mov $-ENOSYS, %rax
pushq $VGCF_in_syscall
jmp hypercall_iret