xen: make direct versions of irq_enable/disable/save/restore to common code
Now that x86-64 has directly accessible percpu variables, it can also
implement the direct versions of these operations, which operate on a
vcpu_info structure directly embedded in the percpu area.
In fact, the 64-bit versions are more or less identical, and so can be
shared. The only two differences are:
1. xen_restore_fl_direct takes its argument in eax on 32-bit, and rdi on 64-bit.
Unfortunately it isn't possible to directly refer to the 2nd lsb of rdi directly
(as you can with %ah), so the code isn't quite as dense.
2. check_events needs to variants to save different registers.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
diff --git a/arch/x86/xen/xen-asm_32.S b/arch/x86/xen/xen-asm_32.S
index 42786f5..082d173 100644
--- a/arch/x86/xen/xen-asm_32.S
+++ b/arch/x86/xen/xen-asm_32.S
@@ -11,101 +11,28 @@
generally too large to inline anyway.
*/
-#include <linux/linkage.h>
-
-#include <asm/asm-offsets.h>
+//#include <asm/asm-offsets.h>
#include <asm/thread_info.h>
-#include <asm/percpu.h>
#include <asm/processor-flags.h>
#include <asm/segment.h>
#include <xen/interface/xen.h>
-#define RELOC(x, v) .globl x##_reloc; x##_reloc=v
-#define ENDPATCH(x) .globl x##_end; x##_end=.
-
-/* Pseudo-flag used for virtual NMI, which we don't implement yet */
-#define XEN_EFLAGS_NMI 0x80000000
+#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.
+ Force an event check by making a hypercall,
+ but preserve regs before making the call.
*/
-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. */
-
- /* Test for pending */
- testb $0xff, PER_CPU_VAR(xen_vcpu_info)+XEN_vcpu_info_pending
- jz 1f
-
-2: call check_events
-1:
-ENDPATCH(xen_irq_enable_direct)
+check_events:
+ push %eax
+ push %ecx
+ push %edx
+ call xen_force_evtchn_callback
+ pop %edx
+ pop %ecx
+ pop %eax
ret
- ENDPROC(xen_irq_enable_direct)
- RELOC(xen_irq_enable_direct, 2b+1)
-
-
-/*
- 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
-ENDPATCH(xen_irq_disable_direct)
- ret
- ENDPROC(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).
- */
-ENTRY(xen_save_fl_direct)
- testb $0xff, PER_CPU_VAR(xen_vcpu_info)+XEN_vcpu_info_mask
- setz %ah
- addb %ah,%ah
-ENDPATCH(xen_save_fl_direct)
- ret
- ENDPROC(xen_save_fl_direct)
- RELOC(xen_save_fl_direct, 0)
-
-
-/*
- 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)
- testb $X86_EFLAGS_IF>>8, %ah
- 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. */
-
- /* check for unmasked and pending */
- cmpw $0x0001, PER_CPU_VAR(xen_vcpu_info)+XEN_vcpu_info_pending
- jz 1f
-2: call check_events
-1:
-ENDPATCH(xen_restore_fl_direct)
- ret
- ENDPROC(xen_restore_fl_direct)
- RELOC(xen_restore_fl_direct, 2b+1)
/*
We can't use sysexit directly, because we're not running in ring0.
@@ -289,17 +216,3 @@
lea 4(%edi),%esp /* point esp to new frame */
2: jmp xen_do_upcall
-
-/*
- Force an event check by making a hypercall,
- but preserve regs before making the call.
- */
-check_events:
- push %eax
- push %ecx
- push %edx
- call xen_force_evtchn_callback
- pop %edx
- pop %ecx
- pop %eax
- ret