aboutsummaryrefslogtreecommitdiffstats
path: root/arch/x86/xen/xen-asm_64.S
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86/xen/xen-asm_64.S')
-rw-r--r--arch/x86/xen/xen-asm_64.S147
1 files changed, 9 insertions, 138 deletions
diff --git a/arch/x86/xen/xen-asm_64.S b/arch/x86/xen/xen-asm_64.S
index 05794c566e87..d205a283efe0 100644
--- a/arch/x86/xen/xen-asm_64.S
+++ b/arch/x86/xen/xen-asm_64.S
@@ -11,143 +11,14 @@
11 generally too large to inline anyway. 11 generally too large to inline anyway.
12 */ 12 */
13 13
14#include <linux/linkage.h>
15
16#include <asm/asm-offsets.h>
17#include <asm/processor-flags.h>
18#include <asm/errno.h> 14#include <asm/errno.h>
15#include <asm/percpu.h>
16#include <asm/processor-flags.h>
19#include <asm/segment.h> 17#include <asm/segment.h>
20 18
21#include <xen/interface/xen.h> 19#include <xen/interface/xen.h>
22 20
23#define RELOC(x, v) .globl x##_reloc; x##_reloc=v 21#include "xen-asm.h"
24#define ENDPATCH(x) .globl x##_end; x##_end=.
25
26/* Pseudo-flag used for virtual NMI, which we don't implement yet */
27#define XEN_EFLAGS_NMI 0x80000000
28
29#if 1
30/*
31 x86-64 does not yet support direct access to percpu variables
32 via a segment override, so we just need to make sure this code
33 never gets used
34 */
35#define BUG ud2a
36#define PER_CPU_VAR(var, off) 0xdeadbeef
37#endif
38
39/*
40 Enable events. This clears the event mask and tests the pending
41 event status with one and operation. If there are pending
42 events, then enter the hypervisor to get them handled.
43 */
44ENTRY(xen_irq_enable_direct)
45 BUG
46
47 /* Unmask events */
48 movb $0, PER_CPU_VAR(xen_vcpu_info, XEN_vcpu_info_mask)
49
50 /* Preempt here doesn't matter because that will deal with
51 any pending interrupts. The pending check may end up being
52 run on the wrong CPU, but that doesn't hurt. */
53
54 /* Test for pending */
55 testb $0xff, PER_CPU_VAR(xen_vcpu_info, XEN_vcpu_info_pending)
56 jz 1f
57
582: call check_events
591:
60ENDPATCH(xen_irq_enable_direct)
61 ret
62 ENDPROC(xen_irq_enable_direct)
63 RELOC(xen_irq_enable_direct, 2b+1)
64
65/*
66 Disabling events is simply a matter of making the event mask
67 non-zero.
68 */
69ENTRY(xen_irq_disable_direct)
70 BUG
71
72 movb $1, PER_CPU_VAR(xen_vcpu_info, XEN_vcpu_info_mask)
73ENDPATCH(xen_irq_disable_direct)
74 ret
75 ENDPROC(xen_irq_disable_direct)
76 RELOC(xen_irq_disable_direct, 0)
77
78/*
79 (xen_)save_fl is used to get the current interrupt enable status.
80 Callers expect the status to be in X86_EFLAGS_IF, and other bits
81 may be set in the return value. We take advantage of this by
82 making sure that X86_EFLAGS_IF has the right value (and other bits
83 in that byte are 0), but other bits in the return value are
84 undefined. We need to toggle the state of the bit, because
85 Xen and x86 use opposite senses (mask vs enable).
86 */
87ENTRY(xen_save_fl_direct)
88 BUG
89
90 testb $0xff, PER_CPU_VAR(xen_vcpu_info, XEN_vcpu_info_mask)
91 setz %ah
92 addb %ah,%ah
93ENDPATCH(xen_save_fl_direct)
94 ret
95 ENDPROC(xen_save_fl_direct)
96 RELOC(xen_save_fl_direct, 0)
97
98/*
99 In principle the caller should be passing us a value return
100 from xen_save_fl_direct, but for robustness sake we test only
101 the X86_EFLAGS_IF flag rather than the whole byte. After
102 setting the interrupt mask state, it checks for unmasked
103 pending events and enters the hypervisor to get them delivered
104 if so.
105 */
106ENTRY(xen_restore_fl_direct)
107 BUG
108
109 testb $X86_EFLAGS_IF>>8, %ah
110 setz PER_CPU_VAR(xen_vcpu_info, XEN_vcpu_info_mask)
111 /* Preempt here doesn't matter because that will deal with
112 any pending interrupts. The pending check may end up being
113 run on the wrong CPU, but that doesn't hurt. */
114
115 /* check for unmasked and pending */
116 cmpw $0x0001, PER_CPU_VAR(xen_vcpu_info, XEN_vcpu_info_pending)
117 jz 1f
1182: call check_events
1191:
120ENDPATCH(xen_restore_fl_direct)
121 ret
122 ENDPROC(xen_restore_fl_direct)
123 RELOC(xen_restore_fl_direct, 2b+1)
124
125
126/*
127 Force an event check by making a hypercall,
128 but preserve regs before making the call.
129 */
130check_events:
131 push %rax
132 push %rcx
133 push %rdx
134 push %rsi
135 push %rdi
136 push %r8
137 push %r9
138 push %r10
139 push %r11
140 call xen_force_evtchn_callback
141 pop %r11
142 pop %r10
143 pop %r9
144 pop %r8
145 pop %rdi
146 pop %rsi
147 pop %rdx
148 pop %rcx
149 pop %rax
150 ret
151 22
152ENTRY(xen_adjust_exception_frame) 23ENTRY(xen_adjust_exception_frame)
153 mov 8+0(%rsp),%rcx 24 mov 8+0(%rsp),%rcx
@@ -195,11 +66,11 @@ RELOC(xen_sysexit, 1b+1)
195ENTRY(xen_sysret64) 66ENTRY(xen_sysret64)
196 /* We're already on the usermode stack at this point, but still 67 /* We're already on the usermode stack at this point, but still
197 with the kernel gs, so we can easily switch back */ 68 with the kernel gs, so we can easily switch back */
198 movq %rsp, %gs:pda_oldrsp 69 movq %rsp, PER_CPU_VAR(old_rsp)
199 movq %gs:pda_kernelstack,%rsp 70 movq PER_CPU_VAR(kernel_stack),%rsp
200 71
201 pushq $__USER_DS 72 pushq $__USER_DS
202 pushq %gs:pda_oldrsp 73 pushq PER_CPU_VAR(old_rsp)
203 pushq %r11 74 pushq %r11
204 pushq $__USER_CS 75 pushq $__USER_CS
205 pushq %rcx 76 pushq %rcx
@@ -212,11 +83,11 @@ RELOC(xen_sysret64, 1b+1)
212ENTRY(xen_sysret32) 83ENTRY(xen_sysret32)
213 /* We're already on the usermode stack at this point, but still 84 /* We're already on the usermode stack at this point, but still
214 with the kernel gs, so we can easily switch back */ 85 with the kernel gs, so we can easily switch back */
215 movq %rsp, %gs:pda_oldrsp 86 movq %rsp, PER_CPU_VAR(old_rsp)
216 movq %gs:pda_kernelstack, %rsp 87 movq PER_CPU_VAR(kernel_stack), %rsp
217 88
218 pushq $__USER32_DS 89 pushq $__USER32_DS
219 pushq %gs:pda_oldrsp 90 pushq PER_CPU_VAR(old_rsp)
220 pushq %r11 91 pushq %r11
221 pushq $__USER32_CS 92 pushq $__USER32_CS
222 pushq %rcx 93 pushq %rcx