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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] Cleanup i386 entry.S.
# HG changeset patch
# User cl349@xxxxxxxxxxxxxxxxxxxx
# Node ID b41ad96f1242cfd1acdbaa3210ef4c7b49160d33
# Parent 51c59d5d76b05dc5ce849e8e983f1683d7096881
Cleanup i386 entry.S.
Many of the changes to entry.S can be removed because we don't support
CONFIG_PREEMPT anymore.
Signed-off-by: Christian Limpach <Christian.Limpach@xxxxxxxxxxxx>
diff -r 51c59d5d76b0 -r b41ad96f1242
linux-2.6-xen-sparse/arch/i386/kernel/entry-xen.S
--- a/linux-2.6-xen-sparse/arch/i386/kernel/entry-xen.S Tue Mar 7 13:40:23 2006
+++ b/linux-2.6-xen-sparse/arch/i386/kernel/entry-xen.S Tue Mar 7 15:48:36 2006
@@ -79,6 +79,10 @@
/* Pseudo-eflags. */
NMI_MASK = 0x80000000
+#ifndef CONFIG_XEN
+#define DISABLE_INTERRUPTS cli
+#define ENABLE_INTERRUPTS sti
+#else
/* Offsets into shared_info_t. */
#define evtchn_upcall_pending /* 0 */
#define evtchn_upcall_mask 1
@@ -86,33 +90,24 @@
#define sizeof_vcpu_shift 6
#ifdef CONFIG_SMP
-#define preempt_disable(reg) incl TI_preempt_count(reg)
-#define preempt_enable(reg) decl TI_preempt_count(reg)
-#define XEN_GET_VCPU_INFO(reg) preempt_disable(%ebp) ; \
- movl TI_cpu(%ebp),reg ; \
- shl $sizeof_vcpu_shift,reg ; \
- addl HYPERVISOR_shared_info,reg
-#define XEN_PUT_VCPU_INFO(reg) preempt_enable(%ebp)
-#define XEN_PUT_VCPU_INFO_fixup .byte 0xff,0xff,0xff
+#define GET_VCPU_INFO movl TI_cpu(%ebp),%esi ; \
+ shl $sizeof_vcpu_shift,%esi ; \
+ addl HYPERVISOR_shared_info,%esi
#else
-#define XEN_GET_VCPU_INFO(reg) movl HYPERVISOR_shared_info,reg
-#define XEN_PUT_VCPU_INFO(reg)
-#define XEN_PUT_VCPU_INFO_fixup
-#endif
-
-#define XEN_LOCKED_BLOCK_EVENTS(reg) movb $1,evtchn_upcall_mask(reg)
-#define XEN_LOCKED_UNBLOCK_EVENTS(reg) movb $0,evtchn_upcall_mask(reg)
-#define XEN_BLOCK_EVENTS(reg) XEN_GET_VCPU_INFO(reg) ; \
- XEN_LOCKED_BLOCK_EVENTS(reg) ; \
- XEN_PUT_VCPU_INFO(reg)
-#define XEN_UNBLOCK_EVENTS(reg) XEN_GET_VCPU_INFO(reg)
; \
- XEN_LOCKED_UNBLOCK_EVENTS(reg) ; \
- XEN_PUT_VCPU_INFO(reg)
-#define XEN_TEST_PENDING(reg) testb $0xFF,evtchn_upcall_pending(reg)
+#define GET_VCPU_INFO movl HYPERVISOR_shared_info,%esi
+#endif
+
+#define __DISABLE_INTERRUPTS movb $1,evtchn_upcall_mask(%esi)
+#define __ENABLE_INTERRUPTS movb $0,evtchn_upcall_mask(%esi)
+#define DISABLE_INTERRUPTS GET_VCPU_INFO ; \
+ __DISABLE_INTERRUPTS
+#define ENABLE_INTERRUPTS GET_VCPU_INFO ; \
+ __ENABLE_INTERRUPTS
+#define __TEST_PENDING testb $0xFF,evtchn_upcall_pending(%esi)
+#endif
#ifdef CONFIG_PREEMPT
-#define preempt_stop GET_THREAD_INFO(%ebp) ; \
- XEN_BLOCK_EVENTS(%esi)
+#define preempt_stop cli
#else
#define preempt_stop
#define resume_kernel restore_nocheck
@@ -159,21 +154,6 @@
.previous
-#define RESTORE_ALL \
- RESTORE_REGS \
- addl $4, %esp; \
-1: iret; \
-.section .fixup,"ax"; \
-2: pushl $0; \
- pushl $do_iret_error; \
- jmp error_code; \
-.previous; \
-.section __ex_table,"a";\
- .align 4; \
- .long 1b,2b; \
-.previous
-
-
ENTRY(ret_from_fork)
pushl %eax
call schedule_tail
@@ -199,7 +179,7 @@
testl $(VM_MASK | 2), %eax
jz resume_kernel
ENTRY(resume_userspace)
- XEN_BLOCK_EVENTS(%esi) # make sure we don't miss an interrupt
+ DISABLE_INTERRUPTS # make sure we don't miss an interrupt
# setting need_resched or sigpending
# between sampling and the iret
movl TI_flags(%ebp), %ecx
@@ -210,15 +190,15 @@
#ifdef CONFIG_PREEMPT
ENTRY(resume_kernel)
- XEN_BLOCK_EVENTS(%esi)
+ cli
cmpl $0,TI_preempt_count(%ebp) # non-zero preempt_count ?
jnz restore_nocheck
need_resched:
movl TI_flags(%ebp), %ecx # need_resched set ?
testb $_TIF_NEED_RESCHED, %cl
jz restore_all
- testb $0xFF,EVENT_MASK(%esp) # interrupts off (exception path) ?
- jnz restore_all
+ testl $IF_MASK,EFLAGS(%esp) # interrupts off (exception path) ?
+ jz restore_all
call preempt_schedule_irq
jmp need_resched
#endif
@@ -289,7 +269,7 @@
call *sys_call_table(,%eax,4)
movl %eax,EAX(%esp) # store the return value
syscall_exit:
- XEN_BLOCK_EVENTS(%esi) # make sure we don't miss an interrupt
+ DISABLE_INTERRUPTS # make sure we don't miss an interrupt
# setting need_resched or sigpending
# between sampling and the iret
movl TI_flags(%ebp), %ecx
@@ -297,7 +277,7 @@
jne syscall_exit_work
restore_all:
-#if 0 /* XEN */
+#ifndef CONFIG_XEN
movl EFLAGS(%esp), %eax # mix EFLAGS, SS and CS
# Warning: OLDSS(%esp) contains the wrong/random values if we
# are returning to the kernel.
@@ -307,22 +287,26 @@
andl $(VM_MASK | (4 << 8) | 3), %eax
cmpl $((4 << 8) | 3), %eax
je ldt_ss # returning to user-space with LDT SS
-#endif /* XEN */
+restore_nocheck:
+#else
restore_nocheck:
testl $(VM_MASK|NMI_MASK), EFLAGS(%esp)
jnz hypervisor_iret
movb EVENT_MASK(%esp), %al
notb %al # %al == ~saved_mask
- XEN_GET_VCPU_INFO(%esi)
+ GET_VCPU_INFO
andb evtchn_upcall_mask(%esi),%al
andb $1,%al # %al == mask & ~saved_mask
jnz restore_all_enable_events # != 0 => reenable event delivery
- XEN_PUT_VCPU_INFO(%esi)
+#endif
RESTORE_REGS
addl $4, %esp
1: iret
.section .fixup,"ax"
iret_exc:
+#ifndef CONFIG_XEN
+ sti
+#endif
pushl $0 # no error code
pushl $do_iret_error
jmp error_code
@@ -332,13 +316,7 @@
.long 1b,iret_exc
.previous
-hypervisor_iret:
- andl $~NMI_MASK, EFLAGS(%esp)
- RESTORE_REGS
- addl $4, %esp
- jmp hypercall_page + (__HYPERVISOR_iret * 32)
-
-#if 0 /* XEN */
+#ifndef CONFIG_XEN
ldt_ss:
larl OLDSS(%esp), %eax
jnz restore_nocheck
@@ -363,7 +341,13 @@
.align 4
.long 1b,iret_exc
.previous
-#endif /* XEN */
+#else
+hypervisor_iret:
+ andl $~NMI_MASK, EFLAGS(%esp)
+ RESTORE_REGS
+ addl $4, %esp
+ jmp hypercall_page + (__HYPERVISOR_iret * 32)
+#endif
# perform work that needs to be done immediately before resumption
ALIGN
@@ -372,7 +356,7 @@
jz work_notifysig
work_resched:
call schedule
- XEN_BLOCK_EVENTS(%esi) # make sure we don't miss an interrupt
+ DISABLE_INTERRUPTS # make sure we don't miss an interrupt
# setting need_resched or sigpending
# between sampling and the iret
movl TI_flags(%ebp), %ecx
@@ -424,7 +408,7 @@
syscall_exit_work:
testb $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SINGLESTEP), %cl
jz work_pending
- XEN_UNBLOCK_EVENTS(%esi) # could let do_syscall_trace() call
+ ENABLE_INTERRUPTS # could let do_syscall_trace() call
# schedule() instead
movl %esp, %eax
movl $1, %edx
@@ -444,7 +428,7 @@
movl $-ENOSYS,EAX(%esp)
jmp resume_userspace
-#if 0 /* XEN */
+#ifndef CONFIG_XEN
#define FIXUP_ESPFIX_STACK \
movl %esp, %eax; \
/* switch to 32bit stack using the pointer on top of 16bit stack */ \
@@ -503,7 +487,9 @@
/* The include is where all of the SMP etc. interrupts come from */
#include "entry_arch.h"
-#endif /* XEN */
+#else
+#define UNWIND_ESPFIX_STACK
+#endif
ENTRY(divide_error)
pushl $0 # no error code
@@ -522,7 +508,7 @@
pushl %ebx
cld
pushl %es
-# UNWIND_ESPFIX_STACK
+ UNWIND_ESPFIX_STACK
popl %ecx
movl ES(%esp), %edi # get the function address
movl ORIG_EAX(%esp), %edx # get the error code
@@ -535,6 +521,7 @@
call *%edi
jmp ret_from_exception
+#ifdef CONFIG_XEN
# A note on the "critical region" in our callback handler.
# We want to avoid stacking callback handlers due to events occurring
# during handling of the last event. To do this, we keep events disabled
@@ -561,14 +548,23 @@
ALIGN
restore_all_enable_events:
- XEN_LOCKED_UNBLOCK_EVENTS(%esi)
+ __ENABLE_INTERRUPTS
scrit: /**** START OF CRITICAL REGION ****/
- XEN_TEST_PENDING(%esi)
+ __TEST_PENDING
jnz 14f # process more events if necessary...
- XEN_PUT_VCPU_INFO(%esi)
- RESTORE_ALL
-14: XEN_LOCKED_BLOCK_EVENTS(%esi)
- XEN_PUT_VCPU_INFO(%esi)
+ RESTORE_REGS
+ addl $4, %esp
+1: iret
+.section .fixup,"ax"
+2: pushl $0
+ pushl $do_iret_error
+ jmp error_code
+.previous
+.section __ex_table,"a"
+ .align 4
+ .long 1b,2b
+.previous
+14: __DISABLE_INTERRUPTS
jmp 11b
ecrit: /**** END OF CRITICAL REGION ****/
# [How we do the fixup]. We want to merge the current stack frame with the
@@ -584,7 +580,6 @@
cmpb $0xff,%al # 0xff => vcpu_info critical region
jne 15f
GET_THREAD_INFO(%ebp)
- XEN_PUT_VCPU_INFO(%esi) # abort vcpu_info critical region
xorl %eax,%eax
15: mov %esp,%esi
add %eax,%esi # %esi points at end of src region
@@ -602,9 +597,8 @@
jmp 11b
critical_fixup_table:
- .byte 0xff,0xff,0xff # testb $0xff,(%esi) = XEN_TEST_PENDING
+ .byte 0xff,0xff,0xff # testb $0xff,(%esi) = __TEST_PENDING
.byte 0xff,0xff # jnz 14f
- XEN_PUT_VCPU_INFO_fixup
.byte 0x00 # pop %ebx
.byte 0x04 # pop %ecx
.byte 0x08 # pop %edx
@@ -617,7 +611,6 @@
.byte 0x24,0x24,0x24 # add $4,%esp
.byte 0x28 # iret
.byte 0xff,0xff,0xff,0xff # movb $1,1(%esi)
- XEN_PUT_VCPU_INFO_fixup
.byte 0x00,0x00 # jmp 11b
# Hypervisor uses this for application faults while it executes.
@@ -646,6 +639,7 @@
.long 3b,8b; \
.long 4b,9b; \
.previous
+#endif
ENTRY(coprocessor_error)
pushl $0
@@ -660,7 +654,17 @@
ENTRY(device_not_available)
pushl $-1 # mark this as an int
SAVE_ALL
- #preempt_stop /* This is already an interrupt gate on Xen. */
+#ifndef CONFIG_XEN
+ movl %cr0, %eax
+ testl $0x4, %eax # EM (math emulation bit)
+ je device_available_emulate
+ pushl $0 # temporary storage for ORIG_EIP
+ call math_emulate
+ addl $4, %esp
+ jmp ret_from_exception
+device_available_emulate:
+#endif
+ preempt_stop
call math_state_restore
jmp ret_from_exception
@@ -703,16 +707,7 @@
jmp ret_from_exception
.previous .text
-ENTRY(nmi)
- pushl %eax
- SAVE_ALL
- xorl %edx,%edx # zero error code
- movl %esp,%eax # pt_regs pointer
- call do_nmi
- orl $NMI_MASK, EFLAGS(%esp)
- jmp restore_all
-
-#if 0 /* XEN */
+#ifndef CONFIG_XEN
/*
* NMI is doubly nasty. It can happen _while_ we're handling
* a debug fault, and the debug fault hasn't yet been able to
@@ -783,7 +778,16 @@
.align 4
.long 1b,iret_exc
.previous
-#endif /* XEN */
+#else
+ENTRY(nmi)
+ pushl %eax
+ SAVE_ALL
+ xorl %edx,%edx # zero error code
+ movl %esp,%eax # pt_regs pointer
+ call do_nmi
+ orl $NMI_MASK, EFLAGS(%esp)
+ jmp restore_all
+#endif
KPROBE_ENTRY(int3)
pushl $-1 # mark this as an int
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