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Diffstat (limited to 'arch/x86/xen/xen-asm.S')
-rw-r--r--arch/x86/xen/xen-asm.S78
1 files changed, 40 insertions, 38 deletions
diff --git a/arch/x86/xen/xen-asm.S b/arch/x86/xen/xen-asm.S
index 4c6f9679913..79d7362ad6d 100644
--- a/arch/x86/xen/xen-asm.S
+++ b/arch/x86/xen/xen-asm.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 percpu data) 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 percpu data) of the
+ * operations here; the indirect forms are better handled in C, since
+ * they're generally too large to inline anyway.
*/
#include <asm/asm-offsets.h>
@@ -18,17 +18,19 @@
#include "xen-asm.h"
/*
- Enable events. This clears the event mask and tests the pending
- event status with one and operation. If there are pending
- events, then enter the hypervisor to get them handled.
+ * Enable events. This clears the event mask and tests the pending
+ * event status with one and operation. If there are pending events,
+ * then enter the hypervisor to get them handled.
*/
ENTRY(xen_irq_enable_direct)
/* Unmask events */
movb $0, PER_CPU_VAR(xen_vcpu_info) + XEN_vcpu_info_mask
- /* Preempt here doesn't matter because that will deal with
- any pending interrupts. The pending check may end up being
- run on the wrong CPU, but that doesn't hurt. */
+ /*
+ * Preempt here doesn't matter because that will deal with any
+ * pending interrupts. The pending check may end up being run
+ * on the wrong CPU, but that doesn't hurt.
+ */
/* Test for pending */
testb $0xff, PER_CPU_VAR(xen_vcpu_info) + XEN_vcpu_info_pending
@@ -43,8 +45,8 @@ ENDPATCH(xen_irq_enable_direct)
/*
- Disabling events is simply a matter of making the event mask
- non-zero.
+ * Disabling events is simply a matter of making the event mask
+ * non-zero.
*/
ENTRY(xen_irq_disable_direct)
movb $1, PER_CPU_VAR(xen_vcpu_info) + XEN_vcpu_info_mask
@@ -54,18 +56,18 @@ ENDPATCH(xen_irq_disable_direct)
RELOC(xen_irq_disable_direct, 0)
/*
- (xen_)save_fl is used to get the current interrupt enable status.
- Callers expect the status to be in X86_EFLAGS_IF, and other bits
- may be set in the return value. We take advantage of this by
- making sure that X86_EFLAGS_IF has the right value (and other bits
- in that byte are 0), but other bits in the return value are
- undefined. We need to toggle the state of the bit, because
- Xen and x86 use opposite senses (mask vs enable).
+ * (xen_)save_fl is used to get the current interrupt enable status.
+ * Callers expect the status to be in X86_EFLAGS_IF, and other bits
+ * may be set in the return value. We take advantage of this by
+ * making sure that X86_EFLAGS_IF has the right value (and other bits
+ * in that byte are 0), but other bits in the return value are
+ * undefined. We need to toggle the state of the bit, because Xen and
+ * x86 use opposite senses (mask vs enable).
*/
ENTRY(xen_save_fl_direct)
testb $0xff, PER_CPU_VAR(xen_vcpu_info) + XEN_vcpu_info_mask
setz %ah
- addb %ah,%ah
+ addb %ah, %ah
ENDPATCH(xen_save_fl_direct)
ret
ENDPROC(xen_save_fl_direct)
@@ -73,12 +75,11 @@ ENDPATCH(xen_save_fl_direct)
/*
- In principle the caller should be passing us a value return
- from xen_save_fl_direct, but for robustness sake we test only
- the X86_EFLAGS_IF flag rather than the whole byte. After
- setting the interrupt mask state, it checks for unmasked
- pending events and enters the hypervisor to get them delivered
- if so.
+ * In principle the caller should be passing us a value return from
+ * xen_save_fl_direct, but for robustness sake we test only the
+ * X86_EFLAGS_IF flag rather than the whole byte. After setting the
+ * interrupt mask state, it checks for unmasked pending events and
+ * enters the hypervisor to get them delivered if so.
*/
ENTRY(xen_restore_fl_direct)
#ifdef CONFIG_X86_64
@@ -87,9 +88,11 @@ ENTRY(xen_restore_fl_direct)
testb $X86_EFLAGS_IF>>8, %ah
#endif
setz PER_CPU_VAR(xen_vcpu_info) + XEN_vcpu_info_mask
- /* Preempt here doesn't matter because that will deal with
- any pending interrupts. The pending check may end up being
- run on the wrong CPU, but that doesn't hurt. */
+ /*
+ * Preempt here doesn't matter because that will deal with any
+ * pending interrupts. The pending check may end up being run
+ * on the wrong CPU, but that doesn't hurt.
+ */
/* check for unmasked and pending */
cmpw $0x0001, PER_CPU_VAR(xen_vcpu_info) + XEN_vcpu_info_pending
@@ -103,8 +106,8 @@ ENDPATCH(xen_restore_fl_direct)
/*
- Force an event check by making a hypercall,
- but preserve regs before making the call.
+ * Force an event check by making a hypercall, but preserve regs
+ * before making the call.
*/
check_events:
#ifdef CONFIG_X86_32
@@ -137,4 +140,3 @@ check_events:
pop %rax
#endif
ret
-