[PATCH 1/8] ia64/pv_ops: split out ia64_swtich_to(), ia64_leave_syscall() and ia64_leave_kernel from entry.S to switch_leave.S for paravirtualization.

From: Isaku Yamahata <yamahata_at_valinux.co.jp>
Date: 2008-02-27 00:58:52
note:
This patch may decrease performance because it eliminates two fall through and
one mov breg hint.

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
---
 arch/ia64/kernel/Makefile       |    2 +-
 arch/ia64/kernel/entry.S        |  564 +------------------------------------
 arch/ia64/kernel/switch_leave.S |  594 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 603 insertions(+), 557 deletions(-)
 create mode 100644 arch/ia64/kernel/switch_leave.S

diff --git a/arch/ia64/kernel/Makefile b/arch/ia64/kernel/Makefile
index 33e5a59..f9bc3c4 100644
--- a/arch/ia64/kernel/Makefile
+++ b/arch/ia64/kernel/Makefile
@@ -4,7 +4,7 @@
 
 extra-y	:= head.o init_task.o vmlinux.lds
 
-obj-y := acpi.o entry.o efi.o efi_stub.o gate-data.o fsys.o ia64_ksyms.o irq.o irq_ia64.o	\
+obj-y := acpi.o entry.o switch_leave.o efi.o efi_stub.o gate-data.o fsys.o ia64_ksyms.o irq.o irq_ia64.o	\
 	 irq_lsapic.o ivt.o machvec.o pal.o patch.o process.o perfmon.o ptrace.o sal.o		\
 	 salinfo.o semaphore.o setup.o signal.o sys_ia64.o time.o traps.o unaligned.o \
 	 unwind.o mca.o mca_asm.o topology.o
diff --git a/arch/ia64/kernel/entry.S b/arch/ia64/kernel/entry.S
index 3c331c4..df8dcc9 100644
--- a/arch/ia64/kernel/entry.S
+++ b/arch/ia64/kernel/entry.S
@@ -14,15 +14,6 @@
  * Copyright (C) 1999 Walt Drummond <drummond@valinux.com>
  */
 /*
- * ia64_switch_to now places correct virtual mapping in in TR2 for
- * kernel stack. This allows us to handle interrupts without changing
- * to physical mode.
- *
- * Jonathan Nicklin	<nicklin@missioncriticallinux.com>
- * Patrick O'Rourke	<orourke@missioncriticallinux.com>
- * 11/07/2000
- */
-/*
  * Global (preserved) predicate usage on syscall entry/exit path:
  *
  *	pKStk:		See entry.h.
@@ -175,68 +166,6 @@ GLOBAL_ENTRY(sys_clone)
 END(sys_clone)
 
 /*
- * prev_task <- ia64_switch_to(struct task_struct *next)
- *	With Ingo's new scheduler, interrupts are disabled when this routine gets
- *	called.  The code starting at .map relies on this.  The rest of the code
- *	doesn't care about the interrupt masking status.
- */
-GLOBAL_ENTRY(ia64_switch_to)
-	.prologue
-	alloc r16=ar.pfs,1,0,0,0
-	DO_SAVE_SWITCH_STACK
-	.body
-
-	adds r22=IA64_TASK_THREAD_KSP_OFFSET,r13
-	movl r25=init_task
-	mov r27=IA64_KR(CURRENT_STACK)
-	adds r21=IA64_TASK_THREAD_KSP_OFFSET,in0
-	dep r20=0,in0,61,3		// physical address of "next"
-	;;
-	st8 [r22]=sp			// save kernel stack pointer of old task
-	shr.u r26=r20,IA64_GRANULE_SHIFT
-	cmp.eq p7,p6=r25,in0
-	;;
-	/*
-	 * If we've already mapped this task's page, we can skip doing it again.
-	 */
-(p6)	cmp.eq p7,p6=r26,r27
-(p6)	br.cond.dpnt .map
-	;;
-.done:
-	ld8 sp=[r21]			// load kernel stack pointer of new task
-	mov IA64_KR(CURRENT)=in0	// update "current" application register
-	mov r8=r13			// return pointer to previously running task
-	mov r13=in0			// set "current" pointer
-	;;
-	DO_LOAD_SWITCH_STACK
-
-#ifdef CONFIG_SMP
-	sync.i				// ensure "fc"s done by this CPU are visible on other CPUs
-#endif
-	br.ret.sptk.many rp		// boogie on out in new context
-
-.map:
-	rsm psr.ic			// interrupts (psr.i) are already disabled here
-	movl r25=PAGE_KERNEL
-	;;
-	srlz.d
-	or r23=r25,r20			// construct PA | page properties
-	mov r25=IA64_GRANULE_SHIFT<<2
-	;;
-	mov cr.itir=r25
-	mov cr.ifa=in0			// VA of next task...
-	;;
-	mov r25=IA64_TR_CURRENT_STACK
-	mov IA64_KR(CURRENT_STACK)=r26	// remember last page we mapped...
-	;;
-	itr.d dtr[r25]=r23		// wire in new mapping...
-	ssm psr.ic			// reenable the psr.ic bit
-	;;
-	srlz.d
-	br.cond.sptk .done
-END(ia64_switch_to)
-
-/*
  * Note that interrupts are enabled during save_switch_stack and load_switch_stack.  This
  * means that we may get an interrupt with "sp" pointing to the new kernel stack while
  * ar.bspstore is still pointing to the old kernel backing store area.  Since ar.rsc,
@@ -570,7 +499,7 @@ GLOBAL_ENTRY(ia64_trace_syscall)
 	br.call.sptk.many rp=syscall_trace_leave // give parent a chance to catch return value
 .ret3:
 (pUStk)	cmp.eq.unc p6,p0=r0,r0			// p6 <- pUStk
-	br.cond.sptk .work_pending_syscall_end
+	br.cond.sptk ia64_work_pending_syscall_end
 
 strace_error:
 	ld8 r3=[r2]				// load pt_regs.r8
@@ -635,160 +564,10 @@ GLOBAL_ENTRY(ia64_ret_from_syscall)
 	adds r2=PT(R8)+16,sp			// r2 = &pt_regs.r8
 	mov r10=r0				// clear error indication in r10
 (p7)	br.cond.spnt handle_syscall_error	// handle potential syscall failure
-END(ia64_ret_from_syscall)
-	// fall through
-/*
- * ia64_leave_syscall(): Same as ia64_leave_kernel, except that it doesn't
- *	need to switch to bank 0 and doesn't restore the scratch registers.
- *	To avoid leaking kernel bits, the scratch registers are set to
- *	the following known-to-be-safe values:
- *
- *		  r1: restored (global pointer)
- *		  r2: cleared
- *		  r3: 1 (when returning to user-level)
- *	      r8-r11: restored (syscall return value(s))
- *		 r12: restored (user-level stack pointer)
- *		 r13: restored (user-level thread pointer)
- *		 r14: set to __kernel_syscall_via_epc
- *		 r15: restored (syscall #)
- *	     r16-r17: cleared
- *		 r18: user-level b6
- *		 r19: cleared
- *		 r20: user-level ar.fpsr
- *		 r21: user-level b0
- *		 r22: cleared
- *		 r23: user-level ar.bspstore
- *		 r24: user-level ar.rnat
- *		 r25: user-level ar.unat
- *		 r26: user-level ar.pfs
- *		 r27: user-level ar.rsc
- *		 r28: user-level ip
- *		 r29: user-level psr
- *		 r30: user-level cfm
- *		 r31: user-level pr
- *	      f6-f11: cleared
- *		  pr: restored (user-level pr)
- *		  b0: restored (user-level rp)
- *	          b6: restored
- *		  b7: set to __kernel_syscall_via_epc
- *	     ar.unat: restored (user-level ar.unat)
- *	      ar.pfs: restored (user-level ar.pfs)
- *	      ar.rsc: restored (user-level ar.rsc)
- *	     ar.rnat: restored (user-level ar.rnat)
- *	 ar.bspstore: restored (user-level ar.bspstore)
- *	     ar.fpsr: restored (user-level ar.fpsr)
- *	      ar.ccv: cleared
- *	      ar.csd: cleared
- *	      ar.ssd: cleared
- */
-ENTRY(ia64_leave_syscall)
-	PT_REGS_UNWIND_INFO(0)
-	/*
-	 * work.need_resched etc. mustn't get changed by this CPU before it returns to
-	 * user- or fsys-mode, hence we disable interrupts early on.
-	 *
-	 * p6 controls whether current_thread_info()->flags needs to be check for
-	 * extra work.  We always check for extra work when returning to user-level.
-	 * With CONFIG_PREEMPT, we also check for extra work when the preempt_count
-	 * is 0.  After extra work processing has been completed, execution
-	 * resumes at .work_processed_syscall with p6 set to 1 if the extra-work-check
-	 * needs to be redone.
-	 */
-#ifdef CONFIG_PREEMPT
-	rsm psr.i				// disable interrupts
-	cmp.eq pLvSys,p0=r0,r0			// pLvSys=1: leave from syscall
-(pKStk) adds r20=TI_PRE_COUNT+IA64_TASK_SIZE,r13
-	;;
-	.pred.rel.mutex pUStk,pKStk
-(pKStk) ld4 r21=[r20]			// r21 <- preempt_count
-(pUStk)	mov r21=0			// r21 <- 0
-	;;
-	cmp.eq p6,p0=r21,r0		// p6 <- pUStk || (preempt_count == 0)
-#else /* !CONFIG_PREEMPT */
-(pUStk)	rsm psr.i
-	cmp.eq pLvSys,p0=r0,r0		// pLvSys=1: leave from syscall
-(pUStk)	cmp.eq.unc p6,p0=r0,r0		// p6 <- pUStk
-#endif
-.work_processed_syscall:
-	adds r2=PT(LOADRS)+16,r12
-	adds r3=PT(AR_BSPSTORE)+16,r12
-	adds r18=TI_FLAGS+IA64_TASK_SIZE,r13
 	;;
-(p6)	ld4 r31=[r18]				// load current_thread_info()->flags
-	ld8 r19=[r2],PT(B6)-PT(LOADRS)		// load ar.rsc value for "loadrs"
-	nop.i 0
-	;;
-	mov r16=ar.bsp				// M2  get existing backing store pointer
-	ld8 r18=[r2],PT(R9)-PT(B6)		// load b6
-(p6)	and r15=TIF_WORK_MASK,r31		// any work other than TIF_SYSCALL_TRACE?
-	;;
-	ld8 r23=[r3],PT(R11)-PT(AR_BSPSTORE)	// load ar.bspstore (may be garbage)
-(p6)	cmp4.ne.unc p6,p0=r15, r0		// any special work pending?
-(p6)	br.cond.spnt .work_pending_syscall
-	;;
-	// start restoring the state saved on the kernel stack (struct pt_regs):
-	ld8 r9=[r2],PT(CR_IPSR)-PT(R9)
-	ld8 r11=[r3],PT(CR_IIP)-PT(R11)
-(pNonSys) break 0		//      bug check: we shouldn't be here if pNonSys is TRUE!
-	;;
-	invala			// M0|1 invalidate ALAT
-	rsm psr.i | psr.ic	// M2   turn off interrupts and interruption collection
-	cmp.eq p9,p0=r0,r0	// A    set p9 to indicate that we should restore cr.ifs
-
-	ld8 r29=[r2],16		// M0|1 load cr.ipsr
-	ld8 r28=[r3],16		// M0|1 load cr.iip
-	mov r22=r0		// A    clear r22
-	;;
-	ld8 r30=[r2],16		// M0|1 load cr.ifs
-	ld8 r25=[r3],16		// M0|1 load ar.unat
-(pUStk) add r14=IA64_TASK_THREAD_ON_USTACK_OFFSET,r13
-	;;
-	ld8 r26=[r2],PT(B0)-PT(AR_PFS)	// M0|1 load ar.pfs
-(pKStk)	mov r22=psr			// M2   read PSR now that interrupts are disabled
-	nop 0
-	;;
-	ld8 r21=[r2],PT(AR_RNAT)-PT(B0) // M0|1 load b0
-	ld8 r27=[r3],PT(PR)-PT(AR_RSC)	// M0|1 load ar.rsc
-	mov f6=f0			// F    clear f6
+	br.cond.sptk.few ia64_leave_syscall
 	;;
-	ld8 r24=[r2],PT(AR_FPSR)-PT(AR_RNAT)	// M0|1 load ar.rnat (may be garbage)
-	ld8 r31=[r3],PT(R1)-PT(PR)		// M0|1 load predicates
-	mov f7=f0				// F    clear f7
-	;;
-	ld8 r20=[r2],PT(R12)-PT(AR_FPSR)	// M0|1 load ar.fpsr
-	ld8.fill r1=[r3],16			// M0|1 load r1
-(pUStk) mov r17=1				// A
-	;;
-(pUStk) st1 [r14]=r17				// M2|3
-	ld8.fill r13=[r3],16			// M0|1
-	mov f8=f0				// F    clear f8
-	;;
-	ld8.fill r12=[r2]			// M0|1 restore r12 (sp)
-	ld8.fill r15=[r3]			// M0|1 restore r15
-	mov b6=r18				// I0   restore b6
-
-	LOAD_PHYS_STACK_REG_SIZE(r17)
-	mov f9=f0					// F    clear f9
-(pKStk) br.cond.dpnt.many skip_rbs_switch		// B
-
-	srlz.d				// M0   ensure interruption collection is off (for cover)
-	shr.u r18=r19,16		// I0|1 get byte size of existing "dirty" partition
-	cover				// B    add current frame into dirty partition & set cr.ifs
-	;;
-	mov r19=ar.bsp			// M2   get new backing store pointer
-	mov f10=f0			// F    clear f10
-
-	nop.m 0
-	movl r14=__kernel_syscall_via_epc // X
-	;;
-	mov.m ar.csd=r0			// M2   clear ar.csd
-	mov.m ar.ccv=r0			// M2   clear ar.ccv
-	mov b7=r14			// I0   clear b7 (hint with __kernel_syscall_via_epc)
-
-	mov.m ar.ssd=r0			// M2   clear ar.ssd
-	mov f11=f0			// F    clear f11
-	br.cond.sptk.many rbs_switch	// B
-END(ia64_leave_syscall)
+END(ia64_ret_from_syscall)
 
 #ifdef CONFIG_IA32_SUPPORT
 GLOBAL_ENTRY(ia64_ret_from_ia32_execve)
@@ -800,339 +579,12 @@ GLOBAL_ENTRY(ia64_ret_from_ia32_execve)
 	st8.spill [r2]=r8	// store return value in slot for r8 and set unat bit
 	.mem.offset 8,0
 	st8.spill [r3]=r0	// clear error indication in slot for r10 and set unat bit
-END(ia64_ret_from_ia32_execve)
-	// fall through
-#endif /* CONFIG_IA32_SUPPORT */
-GLOBAL_ENTRY(ia64_leave_kernel)
-	PT_REGS_UNWIND_INFO(0)
-	/*
-	 * work.need_resched etc. mustn't get changed by this CPU before it returns to
-	 * user- or fsys-mode, hence we disable interrupts early on.
-	 *
-	 * p6 controls whether current_thread_info()->flags needs to be check for
-	 * extra work.  We always check for extra work when returning to user-level.
-	 * With CONFIG_PREEMPT, we also check for extra work when the preempt_count
-	 * is 0.  After extra work processing has been completed, execution
-	 * resumes at .work_processed_syscall with p6 set to 1 if the extra-work-check
-	 * needs to be redone.
-	 */
-#ifdef CONFIG_PREEMPT
-	rsm psr.i				// disable interrupts
-	cmp.eq p0,pLvSys=r0,r0			// pLvSys=0: leave from kernel
-(pKStk)	adds r20=TI_PRE_COUNT+IA64_TASK_SIZE,r13
-	;;
-	.pred.rel.mutex pUStk,pKStk
-(pKStk)	ld4 r21=[r20]			// r21 <- preempt_count
-(pUStk)	mov r21=0			// r21 <- 0
-	;;
-	cmp.eq p6,p0=r21,r0		// p6 <- pUStk || (preempt_count == 0)
-#else
-(pUStk)	rsm psr.i
-	cmp.eq p0,pLvSys=r0,r0		// pLvSys=0: leave from kernel
-(pUStk)	cmp.eq.unc p6,p0=r0,r0		// p6 <- pUStk
-#endif
-.work_processed_kernel:
-	adds r17=TI_FLAGS+IA64_TASK_SIZE,r13
-	;;
-(p6)	ld4 r31=[r17]				// load current_thread_info()->flags
-	adds r21=PT(PR)+16,r12
-	;;
-
-	lfetch [r21],PT(CR_IPSR)-PT(PR)
-	adds r2=PT(B6)+16,r12
-	adds r3=PT(R16)+16,r12
 	;;
-	lfetch [r21]
-	ld8 r28=[r2],8		// load b6
-	adds r29=PT(R24)+16,r12
-
-	ld8.fill r16=[r3],PT(AR_CSD)-PT(R16)
-	adds r30=PT(AR_CCV)+16,r12
-(p6)	and r19=TIF_WORK_MASK,r31		// any work other than TIF_SYSCALL_TRACE?
-	;;
-	ld8.fill r24=[r29]
-	ld8 r15=[r30]		// load ar.ccv
-(p6)	cmp4.ne.unc p6,p0=r19, r0		// any special work pending?
-	;;
-	ld8 r29=[r2],16		// load b7
-	ld8 r30=[r3],16		// load ar.csd
-(p6)	br.cond.spnt .work_pending
-	;;
-	ld8 r31=[r2],16		// load ar.ssd
-	ld8.fill r8=[r3],16
-	;;
-	ld8.fill r9=[r2],16
-	ld8.fill r10=[r3],PT(R17)-PT(R10)
-	;;
-	ld8.fill r11=[r2],PT(R18)-PT(R11)
-	ld8.fill r17=[r3],16
-	;;
-	ld8.fill r18=[r2],16
-	ld8.fill r19=[r3],16
-	;;
-	ld8.fill r20=[r2],16
-	ld8.fill r21=[r3],16
-	mov ar.csd=r30
-	mov ar.ssd=r31
-	;;
-	rsm psr.i | psr.ic	// initiate turning off of interrupt and interruption collection
-	invala			// invalidate ALAT
-	;;
-	ld8.fill r22=[r2],24
-	ld8.fill r23=[r3],24
-	mov b6=r28
-	;;
-	ld8.fill r25=[r2],16
-	ld8.fill r26=[r3],16
-	mov b7=r29
-	;;
-	ld8.fill r27=[r2],16
-	ld8.fill r28=[r3],16
-	;;
-	ld8.fill r29=[r2],16
-	ld8.fill r30=[r3],24
-	;;
-	ld8.fill r31=[r2],PT(F9)-PT(R31)
-	adds r3=PT(F10)-PT(F6),r3
-	;;
-	ldf.fill f9=[r2],PT(F6)-PT(F9)
-	ldf.fill f10=[r3],PT(F8)-PT(F10)
-	;;
-	ldf.fill f6=[r2],PT(F7)-PT(F6)
-	;;
-	ldf.fill f7=[r2],PT(F11)-PT(F7)
-	ldf.fill f8=[r3],32
+	// don't fall through, ia64_leave_kernel may be #define'd
+	br.cond.sptk.few ia64_leave_kernel
 	;;
-	srlz.d	// ensure that inter. collection is off (VHPT is don't care, since text is pinned)
-	mov ar.ccv=r15
-	;;
-	ldf.fill f11=[r2]
-	bsw.0			// switch back to bank 0 (no stop bit required beforehand...)
-	;;
-(pUStk)	mov r18=IA64_KR(CURRENT)// M2 (12 cycle read latency)
-	adds r16=PT(CR_IPSR)+16,r12
-	adds r17=PT(CR_IIP)+16,r12
-
-(pKStk)	mov r22=psr		// M2 read PSR now that interrupts are disabled
-	nop.i 0
-	nop.i 0
-	;;
-	ld8 r29=[r16],16	// load cr.ipsr
-	ld8 r28=[r17],16	// load cr.iip
-	;;
-	ld8 r30=[r16],16	// load cr.ifs
-	ld8 r25=[r17],16	// load ar.unat
-	;;
-	ld8 r26=[r16],16	// load ar.pfs
-	ld8 r27=[r17],16	// load ar.rsc
-	cmp.eq p9,p0=r0,r0	// set p9 to indicate that we should restore cr.ifs
-	;;
-	ld8 r24=[r16],16	// load ar.rnat (may be garbage)
-	ld8 r23=[r17],16	// load ar.bspstore (may be garbage)
-	;;
-	ld8 r31=[r16],16	// load predicates
-	ld8 r21=[r17],16	// load b0
-	;;
-	ld8 r19=[r16],16	// load ar.rsc value for "loadrs"
-	ld8.fill r1=[r17],16	// load r1
-	;;
-	ld8.fill r12=[r16],16
-	ld8.fill r13=[r17],16
-(pUStk)	adds r18=IA64_TASK_THREAD_ON_USTACK_OFFSET,r18
-	;;
-	ld8 r20=[r16],16	// ar.fpsr
-	ld8.fill r15=[r17],16
-	;;
-	ld8.fill r14=[r16],16
-	ld8.fill r2=[r17]
-(pUStk)	mov r17=1
-	;;
-	ld8.fill r3=[r16]
-(pUStk)	st1 [r18]=r17		// restore current->thread.on_ustack
-	shr.u r18=r19,16	// get byte size of existing "dirty" partition
-	;;
-	mov r16=ar.bsp		// get existing backing store pointer
-	LOAD_PHYS_STACK_REG_SIZE(r17)
-(pKStk)	br.cond.dpnt skip_rbs_switch
-
-	/*
-	 * Restore user backing store.
-	 *
-	 * NOTE: alloc, loadrs, and cover can't be predicated.
-	 */
-(pNonSys) br.cond.dpnt dont_preserve_current_frame
-	cover				// add current frame into dirty partition and set cr.ifs
-	;;
-	mov r19=ar.bsp			// get new backing store pointer
-rbs_switch:
-	sub r16=r16,r18			// krbs = old bsp - size of dirty partition
-	cmp.ne p9,p0=r0,r0		// clear p9 to skip restore of cr.ifs
-	;;
-	sub r19=r19,r16			// calculate total byte size of dirty partition
-	add r18=64,r18			// don't force in0-in7 into memory...
-	;;
-	shl r19=r19,16			// shift size of dirty partition into loadrs position
-	;;
-dont_preserve_current_frame:
-	/*
-	 * To prevent leaking bits between the kernel and user-space,
-	 * we must clear the stacked registers in the "invalid" partition here.
-	 * Not pretty, but at least it's fast (3.34 registers/cycle on Itanium,
-	 * 5 registers/cycle on McKinley).
-	 */
-#	define pRecurse	p6
-#	define pReturn	p7
-#ifdef CONFIG_ITANIUM
-#	define Nregs	10
-#else
-#	define Nregs	14
-#endif
-	alloc loc0=ar.pfs,2,Nregs-2,2,0
-	shr.u loc1=r18,9		// RNaTslots <= floor(dirtySize / (64*8))
-	sub r17=r17,r18			// r17 = (physStackedSize + 8) - dirtySize
-	;;
-	mov ar.rsc=r19			// load ar.rsc to be used for "loadrs"
-	shladd in0=loc1,3,r17
-	mov in1=0
-	;;
-	TEXT_ALIGN(32)
-rse_clear_invalid:
-#ifdef CONFIG_ITANIUM
-	// cycle 0
- { .mii
-	alloc loc0=ar.pfs,2,Nregs-2,2,0
-	cmp.lt pRecurse,p0=Nregs*8,in0	// if more than Nregs regs left to clear, (re)curse
-	add out0=-Nregs*8,in0
-}{ .mfb
-	add out1=1,in1			// increment recursion count
-	nop.f 0
-	nop.b 0				// can't do br.call here because of alloc (WAW on CFM)
-	;;
-}{ .mfi	// cycle 1
-	mov loc1=0
-	nop.f 0
-	mov loc2=0
-}{ .mib
-	mov loc3=0
-	mov loc4=0
-(pRecurse) br.call.sptk.many b0=rse_clear_invalid
-
-}{ .mfi	// cycle 2
-	mov loc5=0
-	nop.f 0
-	cmp.ne pReturn,p0=r0,in1	// if recursion count != 0, we need to do a br.ret
-}{ .mib
-	mov loc6=0
-	mov loc7=0
-(pReturn) br.ret.sptk.many b0
-}
-#else /* !CONFIG_ITANIUM */
-	alloc loc0=ar.pfs,2,Nregs-2,2,0
-	cmp.lt pRecurse,p0=Nregs*8,in0	// if more than Nregs regs left to clear, (re)curse
-	add out0=-Nregs*8,in0
-	add out1=1,in1			// increment recursion count
-	mov loc1=0
-	mov loc2=0
-	;;
-	mov loc3=0
-	mov loc4=0
-	mov loc5=0
-	mov loc6=0
-	mov loc7=0
-(pRecurse) br.call.dptk.few b0=rse_clear_invalid
-	;;
-	mov loc8=0
-	mov loc9=0
-	cmp.ne pReturn,p0=r0,in1	// if recursion count != 0, we need to do a br.ret
-	mov loc10=0
-	mov loc11=0
-(pReturn) br.ret.dptk.many b0
-#endif /* !CONFIG_ITANIUM */
-#	undef pRecurse
-#	undef pReturn
-	;;
-	alloc r17=ar.pfs,0,0,0,0	// drop current register frame
-	;;
-	loadrs
-	;;
-skip_rbs_switch:
-	mov ar.unat=r25		// M2
-(pKStk)	extr.u r22=r22,21,1	// I0 extract current value of psr.pp from r22
-(pLvSys)mov r19=r0		// A  clear r19 for leave_syscall, no-op otherwise
-	;;
-(pUStk)	mov ar.bspstore=r23	// M2
-(pKStk)	dep r29=r22,r29,21,1	// I0 update ipsr.pp with psr.pp
-(pLvSys)mov r16=r0		// A  clear r16 for leave_syscall, no-op otherwise
-	;;
-	mov cr.ipsr=r29		// M2
-	mov ar.pfs=r26		// I0
-(pLvSys)mov r17=r0		// A  clear r17 for leave_syscall, no-op otherwise
-
-(p9)	mov cr.ifs=r30		// M2
-	mov b0=r21		// I0
-(pLvSys)mov r18=r0		// A  clear r18 for leave_syscall, no-op otherwise
-
-	mov ar.fpsr=r20		// M2
-	mov cr.iip=r28		// M2
-	nop 0
-	;;
-(pUStk)	mov ar.rnat=r24		// M2 must happen with RSE in lazy mode
-	nop 0
-(pLvSys)mov r2=r0
-
-	mov ar.rsc=r27		// M2
-	mov pr=r31,-1		// I0
-	rfi			// B
-
-	/*
-	 * On entry:
-	 *	r20 = &current->thread_info->pre_count (if CONFIG_PREEMPT)
-	 *	r31 = current->thread_info->flags
-	 * On exit:
-	 *	p6 = TRUE if work-pending-check needs to be redone
-	 */
-.work_pending_syscall:
-	add r2=-8,r2
-	add r3=-8,r3
-	;;
-	st8 [r2]=r8
-	st8 [r3]=r10
-.work_pending:
-	tbit.z p6,p0=r31,TIF_NEED_RESCHED		// current_thread_info()->need_resched==0?
-(p6)	br.cond.sptk.few .notify
-#ifdef CONFIG_PREEMPT
-(pKStk) dep r21=-1,r0,PREEMPT_ACTIVE_BIT,1
-	;;
-(pKStk) st4 [r20]=r21
-	ssm psr.i		// enable interrupts
-#endif
-	br.call.spnt.many rp=schedule
-.ret9:	cmp.eq p6,p0=r0,r0				// p6 <- 1
-	rsm psr.i		// disable interrupts
-	;;
-#ifdef CONFIG_PREEMPT
-(pKStk)	adds r20=TI_PRE_COUNT+IA64_TASK_SIZE,r13
-	;;
-(pKStk)	st4 [r20]=r0		// preempt_count() <- 0
-#endif
-(pLvSys)br.cond.sptk.few  .work_pending_syscall_end
-	br.cond.sptk.many .work_processed_kernel	// re-check
-
-.notify:
-(pUStk)	br.call.spnt.many rp=notify_resume_user
-.ret10:	cmp.ne p6,p0=r0,r0				// p6 <- 0
-(pLvSys)br.cond.sptk.few  .work_pending_syscall_end
-	br.cond.sptk.many .work_processed_kernel	// don't re-check
-
-.work_pending_syscall_end:
-	adds r2=PT(R8)+16,r12
-	adds r3=PT(R10)+16,r12
-	;;
-	ld8 r8=[r2]
-	ld8 r10=[r3]
-	br.cond.sptk.many .work_processed_syscall	// re-check
-
-END(ia64_leave_kernel)
+END(ia64_ret_from_ia32_execve)
+#endif /* CONFIG_IA32_SUPPORT */
 
 ENTRY(handle_syscall_error)
 	/*
@@ -1234,7 +686,7 @@ ENTRY(sys_rt_sigreturn)
 	adds sp=16,sp
 	;;
 	ld8 r9=[sp]				// load new ar.unat
-	mov.sptk b7=r8,ia64_leave_kernel
+	mov b7=r8
 	;;
 	mov ar.unat=r9
 	br.many b7
diff --git a/arch/ia64/kernel/switch_leave.S b/arch/ia64/kernel/switch_leave.S
new file mode 100644
index 0000000..5ca5b84
--- /dev/null
+++ b/arch/ia64/kernel/switch_leave.S
@@ -0,0 +1,594 @@
+/*
+ * arch/ia64/kernel/switch_leave.S
+ * Kernel entry points.
+ * ia64_switch_to(), ia64_leave_syscall() and ia64_leave_kernel()
+ * split from arch/ia64/kernel/entry.S for paravirtualization
+ *
+ * Copyright (C) 1998-2003, 2005 Hewlett-Packard Co
+ *	David Mosberger-Tang <davidm@hpl.hp.com>
+ * Copyright (C) 1999, 2002-2003
+ *	Asit Mallick <Asit.K.Mallick@intel.com>
+ * 	Don Dugger <Don.Dugger@intel.com>
+ *	Suresh Siddha <suresh.b.siddha@intel.com>
+ *	Fenghua Yu <fenghua.yu@intel.com>
+ * Copyright (C) 1999 VA Linux Systems
+ * Copyright (C) 1999 Walt Drummond <drummond@valinux.com>
+ */
+/*
+ * ia64_switch_to now places correct virtual mapping in in TR2 for
+ * kernel stack. This allows us to handle interrupts without changing
+ * to physical mode.
+ *
+ * Jonathan Nicklin	<nicklin@missioncriticallinux.com>
+ * Patrick O'Rourke	<orourke@missioncriticallinux.com>
+ * 11/07/2000
+ */
+/*
+ * Copyright (c) 2008 Isaku Yamahata <yamahata at valinux co jp>
+ *                    VA Linux Systems Japan K.K.
+ *                    pv_ops.
+ */
+/*
+ * Global (preserved) predicate usage on syscall entry/exit path:
+ *
+ *	pKStk:		See entry.h.
+ *	pUStk:		See entry.h.
+ *	pSys:		See entry.h.
+ *	pNonSys:	!pSys
+ */
+
+
+#include <asm/asmmacro.h>
+#include <asm/kregs.h>
+#include <asm/asm-offsets.h>
+#include <asm/pgtable.h>
+#include <asm/thread_info.h>
+
+#include "minstate.h"
+
+
+/*
+ * prev_task <- ia64_switch_to(struct task_struct *next)
+ *	With Ingo's new scheduler, interrupts are disabled when this routine gets
+ *	called.  The code starting at .map relies on this.  The rest of the code
+ *	doesn't care about the interrupt masking status.
+ */
+GLOBAL_ENTRY(ia64_switch_to)
+	.prologue
+	alloc r16=ar.pfs,1,0,0,0
+	DO_SAVE_SWITCH_STACK
+	.body
+
+	adds r22=IA64_TASK_THREAD_KSP_OFFSET,r13
+	movl r25=init_task
+	mov r27=IA64_KR(CURRENT_STACK)
+	adds r21=IA64_TASK_THREAD_KSP_OFFSET,in0
+	dep r20=0,in0,61,3		// physical address of "next"
+	;;
+	st8 [r22]=sp			// save kernel stack pointer of old task
+	shr.u r26=r20,IA64_GRANULE_SHIFT
+	cmp.eq p7,p6=r25,in0
+	;;
+	/*
+	 * If we've already mapped this task's page, we can skip doing it again.
+	 */
+(p6)	cmp.eq p7,p6=r26,r27
+(p6)	br.cond.dpnt .map
+	;;
+.done:
+	ld8 sp=[r21]			// load kernel stack pointer of new task
+	mov IA64_KR(CURRENT)=in0	// update "current" application register
+	mov r8=r13			// return pointer to previously running task
+	mov r13=in0			// set "current" pointer
+	;;
+	DO_LOAD_SWITCH_STACK
+
+#ifdef CONFIG_SMP
+	sync.i				// ensure "fc"s done by this CPU are visible on other CPUs
+#endif
+	br.ret.sptk.many rp		// boogie on out in new context
+
+.map:
+	rsm psr.ic			// interrupts (psr.i) are already disabled here
+	movl r25=PAGE_KERNEL
+	;;
+	srlz.d
+	or r23=r25,r20			// construct PA | page properties
+	mov r25=IA64_GRANULE_SHIFT<<2
+	;;
+	mov cr.itir=r25
+	mov cr.ifa=in0			// VA of next task...
+	;;
+	mov r25=IA64_TR_CURRENT_STACK
+	mov IA64_KR(CURRENT_STACK)=r26	// remember last page we mapped...
+	;;
+	itr.d dtr[r25]=r23		// wire in new mapping...
+	ssm psr.ic			// reenable the psr.ic bit
+	;;
+	srlz.d
+	br.cond.sptk .done
+END(ia64_switch_to)
+
+/*
+ * ia64_leave_syscall(): Same as ia64_leave_kernel, except that it doesn't
+ *	need to switch to bank 0 and doesn't restore the scratch registers.
+ *	To avoid leaking kernel bits, the scratch registers are set to
+ *	the following known-to-be-safe values:
+ *
+ *		  r1: restored (global pointer)
+ *		  r2: cleared
+ *		  r3: 1 (when returning to user-level)
+ *	      r8-r11: restored (syscall return value(s))
+ *		 r12: restored (user-level stack pointer)
+ *		 r13: restored (user-level thread pointer)
+ *		 r14: set to __kernel_syscall_via_epc
+ *		 r15: restored (syscall #)
+ *	     r16-r17: cleared
+ *		 r18: user-level b6
+ *		 r19: cleared
+ *		 r20: user-level ar.fpsr
+ *		 r21: user-level b0
+ *		 r22: cleared
+ *		 r23: user-level ar.bspstore
+ *		 r24: user-level ar.rnat
+ *		 r25: user-level ar.unat
+ *		 r26: user-level ar.pfs
+ *		 r27: user-level ar.rsc
+ *		 r28: user-level ip
+ *		 r29: user-level psr
+ *		 r30: user-level cfm
+ *		 r31: user-level pr
+ *	      f6-f11: cleared
+ *		  pr: restored (user-level pr)
+ *		  b0: restored (user-level rp)
+ *	          b6: restored
+ *		  b7: set to __kernel_syscall_via_epc
+ *	     ar.unat: restored (user-level ar.unat)
+ *	      ar.pfs: restored (user-level ar.pfs)
+ *	      ar.rsc: restored (user-level ar.rsc)
+ *	     ar.rnat: restored (user-level ar.rnat)
+ *	 ar.bspstore: restored (user-level ar.bspstore)
+ *	     ar.fpsr: restored (user-level ar.fpsr)
+ *	      ar.ccv: cleared
+ *	      ar.csd: cleared
+ *	      ar.ssd: cleared
+ */
+ENTRY(ia64_leave_syscall)
+	PT_REGS_UNWIND_INFO(0)
+	/*
+	 * work.need_resched etc. mustn't get changed by this CPU before it returns to
+	 * user- or fsys-mode, hence we disable interrupts early on.
+	 *
+	 * p6 controls whether current_thread_info()->flags needs to be check for
+	 * extra work.  We always check for extra work when returning to user-level.
+	 * With CONFIG_PREEMPT, we also check for extra work when the preempt_count
+	 * is 0.  After extra work processing has been completed, execution
+	 * resumes at .work_processed_syscall with p6 set to 1 if the extra-work-check
+	 * needs to be redone.
+	 */
+#ifdef CONFIG_PREEMPT
+	rsm psr.i				// disable interrupts
+	cmp.eq pLvSys,p0=r0,r0			// pLvSys=1: leave from syscall
+(pKStk) adds r20=TI_PRE_COUNT+IA64_TASK_SIZE,r13
+	;;
+	.pred.rel.mutex pUStk,pKStk
+(pKStk) ld4 r21=[r20]			// r21 <- preempt_count
+(pUStk)	mov r21=0			// r21 <- 0
+	;;
+	cmp.eq p6,p0=r21,r0		// p6 <- pUStk || (preempt_count == 0)
+#else /* !CONFIG_PREEMPT */
+(pUStk)	rsm psr.i
+	cmp.eq pLvSys,p0=r0,r0		// pLvSys=1: leave from syscall
+(pUStk)	cmp.eq.unc p6,p0=r0,r0		// p6 <- pUStk
+#endif
+.work_processed_syscall:
+	adds r2=PT(LOADRS)+16,r12
+	adds r3=PT(AR_BSPSTORE)+16,r12
+	adds r18=TI_FLAGS+IA64_TASK_SIZE,r13
+	;;
+(p6)	ld4 r31=[r18]				// load current_thread_info()->flags
+	ld8 r19=[r2],PT(B6)-PT(LOADRS)		// load ar.rsc value for "loadrs"
+	nop.i 0
+	;;
+	mov r16=ar.bsp				// M2  get existing backing store pointer
+	ld8 r18=[r2],PT(R9)-PT(B6)		// load b6
+(p6)	and r15=TIF_WORK_MASK,r31		// any work other than TIF_SYSCALL_TRACE?
+	;;
+	ld8 r23=[r3],PT(R11)-PT(AR_BSPSTORE)	// load ar.bspstore (may be garbage)
+(p6)	cmp4.ne.unc p6,p0=r15, r0		// any special work pending?
+(p6)	br.cond.spnt .work_pending_syscall
+	;;
+	// start restoring the state saved on the kernel stack (struct pt_regs):
+	ld8 r9=[r2],PT(CR_IPSR)-PT(R9)
+	ld8 r11=[r3],PT(CR_IIP)-PT(R11)
+(pNonSys) break 0		//      bug check: we shouldn't be here if pNonSys is TRUE!
+	;;
+	invala			// M0|1 invalidate ALAT
+	rsm psr.i | psr.ic	// M2   turn off interrupts and interruption collection
+	cmp.eq p9,p0=r0,r0	// A    set p9 to indicate that we should restore cr.ifs
+
+	ld8 r29=[r2],16		// M0|1 load cr.ipsr
+	ld8 r28=[r3],16		// M0|1 load cr.iip
+	mov r22=r0		// A    clear r22
+	;;
+	ld8 r30=[r2],16		// M0|1 load cr.ifs
+	ld8 r25=[r3],16		// M0|1 load ar.unat
+(pUStk) add r14=IA64_TASK_THREAD_ON_USTACK_OFFSET,r13
+	;;
+	ld8 r26=[r2],PT(B0)-PT(AR_PFS)	// M0|1 load ar.pfs
+(pKStk)	mov r22=psr			// M2   read PSR now that interrupts are disabled
+	nop 0
+	;;
+	ld8 r21=[r2],PT(AR_RNAT)-PT(B0) // M0|1 load b0
+	ld8 r27=[r3],PT(PR)-PT(AR_RSC)	// M0|1 load ar.rsc
+	mov f6=f0			// F    clear f6
+	;;
+	ld8 r24=[r2],PT(AR_FPSR)-PT(AR_RNAT)	// M0|1 load ar.rnat (may be garbage)
+	ld8 r31=[r3],PT(R1)-PT(PR)		// M0|1 load predicates
+	mov f7=f0				// F    clear f7
+	;;
+	ld8 r20=[r2],PT(R12)-PT(AR_FPSR)	// M0|1 load ar.fpsr
+	ld8.fill r1=[r3],16			// M0|1 load r1
+(pUStk) mov r17=1				// A
+	;;
+(pUStk) st1 [r14]=r17				// M2|3
+	ld8.fill r13=[r3],16			// M0|1
+	mov f8=f0				// F    clear f8
+	;;
+	ld8.fill r12=[r2]			// M0|1 restore r12 (sp)
+	ld8.fill r15=[r3]			// M0|1 restore r15
+	mov b6=r18				// I0   restore b6
+
+	LOAD_PHYS_STACK_REG_SIZE(r17)
+	mov f9=f0					// F    clear f9
+(pKStk) br.cond.dpnt.many skip_rbs_switch		// B
+
+	srlz.d				// M0   ensure interruption collection is off (for cover)
+	shr.u r18=r19,16		// I0|1 get byte size of existing "dirty" partition
+	cover				// B    add current frame into dirty partition & set cr.ifs
+	;;
+	mov r19=ar.bsp			// M2   get new backing store pointer
+	mov f10=f0			// F    clear f10
+
+	nop.m 0
+	movl r14=__kernel_syscall_via_epc // X
+	;;
+	mov.m ar.csd=r0			// M2   clear ar.csd
+	mov.m ar.ccv=r0			// M2   clear ar.ccv
+	mov b7=r14			// I0   clear b7 (hint with __kernel_syscall_via_epc)
+
+	mov.m ar.ssd=r0			// M2   clear ar.ssd
+	mov f11=f0			// F    clear f11
+	br.cond.sptk.many rbs_switch	// B
+END(ia64_leave_syscall)
+
+GLOBAL_ENTRY(ia64_leave_kernel)
+	PT_REGS_UNWIND_INFO(0)
+	/*
+	 * work.need_resched etc. mustn't get changed by this CPU before it returns to
+	 * user- or fsys-mode, hence we disable interrupts early on.
+	 *
+	 * p6 controls whether current_thread_info()->flags needs to be check for
+	 * extra work.  We always check for extra work when returning to user-level.
+	 * With CONFIG_PREEMPT, we also check for extra work when the preempt_count
+	 * is 0.  After extra work processing has been completed, execution
+	 * resumes at .work_processed_syscall with p6 set to 1 if the extra-work-check
+	 * needs to be redone.
+	 */
+#ifdef CONFIG_PREEMPT
+	rsm psr.i				// disable interrupts
+	cmp.eq p0,pLvSys=r0,r0			// pLvSys=0: leave from kernel
+(pKStk)	adds r20=TI_PRE_COUNT+IA64_TASK_SIZE,r13
+	;;
+	.pred.rel.mutex pUStk,pKStk
+(pKStk)	ld4 r21=[r20]			// r21 <- preempt_count
+(pUStk)	mov r21=0			// r21 <- 0
+	;;
+	cmp.eq p6,p0=r21,r0		// p6 <- pUStk || (preempt_count == 0)
+#else
+(pUStk)	rsm psr.i
+	cmp.eq p0,pLvSys=r0,r0		// pLvSys=0: leave from kernel
+(pUStk)	cmp.eq.unc p6,p0=r0,r0		// p6 <- pUStk
+#endif
+.work_processed_kernel:
+	adds r17=TI_FLAGS+IA64_TASK_SIZE,r13
+	;;
+(p6)	ld4 r31=[r17]				// load current_thread_info()->flags
+	adds r21=PT(PR)+16,r12
+	;;
+
+	lfetch [r21],PT(CR_IPSR)-PT(PR)
+	adds r2=PT(B6)+16,r12
+	adds r3=PT(R16)+16,r12
+	;;
+	lfetch [r21]
+	ld8 r28=[r2],8		// load b6
+	adds r29=PT(R24)+16,r12
+
+	ld8.fill r16=[r3],PT(AR_CSD)-PT(R16)
+	adds r30=PT(AR_CCV)+16,r12
+(p6)	and r19=TIF_WORK_MASK,r31		// any work other than TIF_SYSCALL_TRACE?
+	;;
+	ld8.fill r24=[r29]
+	ld8 r15=[r30]		// load ar.ccv
+(p6)	cmp4.ne.unc p6,p0=r19, r0		// any special work pending?
+	;;
+	ld8 r29=[r2],16		// load b7
+	ld8 r30=[r3],16		// load ar.csd
+(p6)	br.cond.spnt .work_pending
+	;;
+	ld8 r31=[r2],16		// load ar.ssd
+	ld8.fill r8=[r3],16
+	;;
+	ld8.fill r9=[r2],16
+	ld8.fill r10=[r3],PT(R17)-PT(R10)
+	;;
+	ld8.fill r11=[r2],PT(R18)-PT(R11)
+	ld8.fill r17=[r3],16
+	;;
+	ld8.fill r18=[r2],16
+	ld8.fill r19=[r3],16
+	;;
+	ld8.fill r20=[r2],16
+	ld8.fill r21=[r3],16
+	mov ar.csd=r30
+	mov ar.ssd=r31
+	;;
+	rsm psr.i | psr.ic	// initiate turning off of interrupt and interruption collection
+	invala			// invalidate ALAT
+	;;
+	ld8.fill r22=[r2],24
+	ld8.fill r23=[r3],24
+	mov b6=r28
+	;;
+	ld8.fill r25=[r2],16
+	ld8.fill r26=[r3],16
+	mov b7=r29
+	;;
+	ld8.fill r27=[r2],16
+	ld8.fill r28=[r3],16
+	;;
+	ld8.fill r29=[r2],16
+	ld8.fill r30=[r3],24
+	;;
+	ld8.fill r31=[r2],PT(F9)-PT(R31)
+	adds r3=PT(F10)-PT(F6),r3
+	;;
+	ldf.fill f9=[r2],PT(F6)-PT(F9)
+	ldf.fill f10=[r3],PT(F8)-PT(F10)
+	;;
+	ldf.fill f6=[r2],PT(F7)-PT(F6)
+	;;
+	ldf.fill f7=[r2],PT(F11)-PT(F7)
+	ldf.fill f8=[r3],32
+	;;
+	srlz.d	// ensure that inter. collection is off (VHPT is don't care, since text is pinned)
+	mov ar.ccv=r15
+	;;
+	ldf.fill f11=[r2]
+	bsw.0			// switch back to bank 0 (no stop bit required beforehand...)
+	;;
+(pUStk)	mov r18=IA64_KR(CURRENT)// M2 (12 cycle read latency)
+	adds r16=PT(CR_IPSR)+16,r12
+	adds r17=PT(CR_IIP)+16,r12
+
+(pKStk)	mov r22=psr		// M2 read PSR now that interrupts are disabled
+	nop.i 0
+	nop.i 0
+	;;
+	ld8 r29=[r16],16	// load cr.ipsr
+	ld8 r28=[r17],16	// load cr.iip
+	;;
+	ld8 r30=[r16],16	// load cr.ifs
+	ld8 r25=[r17],16	// load ar.unat
+	;;
+	ld8 r26=[r16],16	// load ar.pfs
+	ld8 r27=[r17],16	// load ar.rsc
+	cmp.eq p9,p0=r0,r0	// set p9 to indicate that we should restore cr.ifs
+	;;
+	ld8 r24=[r16],16	// load ar.rnat (may be garbage)
+	ld8 r23=[r17],16	// load ar.bspstore (may be garbage)
+	;;
+	ld8 r31=[r16],16	// load predicates
+	ld8 r21=[r17],16	// load b0
+	;;
+	ld8 r19=[r16],16	// load ar.rsc value for "loadrs"
+	ld8.fill r1=[r17],16	// load r1
+	;;
+	ld8.fill r12=[r16],16
+	ld8.fill r13=[r17],16
+(pUStk)	adds r18=IA64_TASK_THREAD_ON_USTACK_OFFSET,r18
+	;;
+	ld8 r20=[r16],16	// ar.fpsr
+	ld8.fill r15=[r17],16
+	;;
+	ld8.fill r14=[r16],16
+	ld8.fill r2=[r17]
+(pUStk)	mov r17=1
+	;;
+	ld8.fill r3=[r16]
+(pUStk)	st1 [r18]=r17		// restore current->thread.on_ustack
+	shr.u r18=r19,16	// get byte size of existing "dirty" partition
+	;;
+	mov r16=ar.bsp		// get existing backing store pointer
+	LOAD_PHYS_STACK_REG_SIZE(r17)
+(pKStk)	br.cond.dpnt skip_rbs_switch
+
+	/*
+	 * Restore user backing store.
+	 *
+	 * NOTE: alloc, loadrs, and cover can't be predicated.
+	 */
+(pNonSys) br.cond.dpnt dont_preserve_current_frame
+	cover				// add current frame into dirty partition and set cr.ifs
+	;;
+	mov r19=ar.bsp			// get new backing store pointer
+rbs_switch:
+	sub r16=r16,r18			// krbs = old bsp - size of dirty partition
+	cmp.ne p9,p0=r0,r0		// clear p9 to skip restore of cr.ifs
+	;;
+	sub r19=r19,r16			// calculate total byte size of dirty partition
+	add r18=64,r18			// don't force in0-in7 into memory...
+	;;
+	shl r19=r19,16			// shift size of dirty partition into loadrs position
+	;;
+dont_preserve_current_frame:
+	/*
+	 * To prevent leaking bits between the kernel and user-space,
+	 * we must clear the stacked registers in the "invalid" partition here.
+	 * Not pretty, but at least it's fast (3.34 registers/cycle on Itanium,
+	 * 5 registers/cycle on McKinley).
+	 */
+#	define pRecurse	p6
+#	define pReturn	p7
+#ifdef CONFIG_ITANIUM
+#	define Nregs	10
+#else
+#	define Nregs	14
+#endif
+	alloc loc0=ar.pfs,2,Nregs-2,2,0
+	shr.u loc1=r18,9		// RNaTslots <= floor(dirtySize / (64*8))
+	sub r17=r17,r18			// r17 = (physStackedSize + 8) - dirtySize
+	;;
+	mov ar.rsc=r19			// load ar.rsc to be used for "loadrs"
+	shladd in0=loc1,3,r17
+	mov in1=0
+	;;
+	TEXT_ALIGN(32)
+rse_clear_invalid:
+#ifdef CONFIG_ITANIUM
+	// cycle 0
+ { .mii
+	alloc loc0=ar.pfs,2,Nregs-2,2,0
+	cmp.lt pRecurse,p0=Nregs*8,in0	// if more than Nregs regs left to clear, (re)curse
+	add out0=-Nregs*8,in0
+}{ .mfb
+	add out1=1,in1			// increment recursion count
+	nop.f 0
+	nop.b 0				// can't do br.call here because of alloc (WAW on CFM)
+	;;
+}{ .mfi	// cycle 1
+	mov loc1=0
+	nop.f 0
+	mov loc2=0
+}{ .mib
+	mov loc3=0
+	mov loc4=0
+(pRecurse) br.call.sptk.many b0=rse_clear_invalid
+
+}{ .mfi	// cycle 2
+	mov loc5=0
+	nop.f 0
+	cmp.ne pReturn,p0=r0,in1	// if recursion count != 0, we need to do a br.ret
+}{ .mib
+	mov loc6=0
+	mov loc7=0
+(pReturn) br.ret.sptk.many b0
+}
+#else /* !CONFIG_ITANIUM */
+	alloc loc0=ar.pfs,2,Nregs-2,2,0
+	cmp.lt pRecurse,p0=Nregs*8,in0	// if more than Nregs regs left to clear, (re)curse
+	add out0=-Nregs*8,in0
+	add out1=1,in1			// increment recursion count
+	mov loc1=0
+	mov loc2=0
+	;;
+	mov loc3=0
+	mov loc4=0
+	mov loc5=0
+	mov loc6=0
+	mov loc7=0
+(pRecurse) br.call.dptk.few b0=rse_clear_invalid
+	;;
+	mov loc8=0
+	mov loc9=0
+	cmp.ne pReturn,p0=r0,in1	// if recursion count != 0, we need to do a br.ret
+	mov loc10=0
+	mov loc11=0
+(pReturn) br.ret.dptk.many b0
+#endif /* !CONFIG_ITANIUM */
+#	undef pRecurse
+#	undef pReturn
+	;;
+	alloc r17=ar.pfs,0,0,0,0	// drop current register frame
+	;;
+	loadrs
+	;;
+skip_rbs_switch:
+	mov ar.unat=r25		// M2
+(pKStk)	extr.u r22=r22,21,1	// I0 extract current value of psr.pp from r22
+(pLvSys)mov r19=r0		// A  clear r19 for leave_syscall, no-op otherwise
+	;;
+(pUStk)	mov ar.bspstore=r23	// M2
+(pKStk)	dep r29=r22,r29,21,1	// I0 update ipsr.pp with psr.pp
+(pLvSys)mov r16=r0		// A  clear r16 for leave_syscall, no-op otherwise
+	;;
+	mov cr.ipsr=r29		// M2
+	mov ar.pfs=r26		// I0
+(pLvSys)mov r17=r0		// A  clear r17 for leave_syscall, no-op otherwise
+
+(p9)	mov cr.ifs=r30		// M2
+	mov b0=r21		// I0
+(pLvSys)mov r18=r0		// A  clear r18 for leave_syscall, no-op otherwise
+
+	mov ar.fpsr=r20		// M2
+	mov cr.iip=r28		// M2
+	nop 0
+	;;
+(pUStk)	mov ar.rnat=r24		// M2 must happen with RSE in lazy mode
+	nop 0
+(pLvSys)mov r2=r0
+
+	mov ar.rsc=r27		// M2
+	mov pr=r31,-1		// I0
+	rfi			// B
+
+	/*
+	 * On entry:
+	 *	r20 = &current->thread_info->pre_count (if CONFIG_PREEMPT)
+	 *	r31 = current->thread_info->flags
+	 * On exit:
+	 *	p6 = TRUE if work-pending-check needs to be redone
+	 */
+.work_pending_syscall:
+	add r2=-8,r2
+	add r3=-8,r3
+	;;
+	st8 [r2]=r8
+	st8 [r3]=r10
+.work_pending:
+	tbit.z p6,p0=r31,TIF_NEED_RESCHED		// current_thread_info()->need_resched==0?
+(p6)	br.cond.sptk.few .notify
+#ifdef CONFIG_PREEMPT
+(pKStk) dep r21=-1,r0,PREEMPT_ACTIVE_BIT,1
+	;;
+(pKStk) st4 [r20]=r21
+	ssm psr.i		// enable interrupts
+#endif
+	br.call.spnt.many rp=schedule
+.ret9:	cmp.eq p6,p0=r0,r0				// p6 <- 1
+	rsm psr.i		// disable interrupts
+	;;
+#ifdef CONFIG_PREEMPT
+(pKStk)	adds r20=TI_PRE_COUNT+IA64_TASK_SIZE,r13
+	;;
+(pKStk)	st4 [r20]=r0		// preempt_count() <- 0
+#endif
+(pLvSys)br.cond.sptk.few  ia64_work_pending_syscall_end
+	br.cond.sptk.many .work_processed_kernel	// re-check
+
+.notify:
+(pUStk)	br.call.spnt.many rp=notify_resume_user
+.ret10:	cmp.ne p6,p0=r0,r0				// p6 <- 0
+(pLvSys)br.cond.sptk.few  ia64_work_pending_syscall_end
+	br.cond.sptk.many .work_processed_kernel	// don't re-check
+
+.global ia64_work_pending_syscall_end;
+ia64_work_pending_syscall_end:
+	adds r2=PT(R8)+16,r12
+	adds r3=PT(R10)+16,r12
+	;;
+	ld8 r8=[r2]
+	ld8 r10=[r3]
+	br.cond.sptk.many .work_processed_syscall	// re-check
+END(ia64_leave_kernel)
-- 
1.5.3

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Received on Wed Feb 27 00:59:49 2008

This archive was generated by hypermail 2.1.8 : 2008-02-27 01:02:03 EST