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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-ia64-devel] [PATCH 4/4] ia64/xen: paravirtualize ia64_switch_to, ia64_leave_syscall and ia64_leave_kernel in entry.S
Signed-off-by: Isaku Yamahata <yamahata@xxxxxxxxxxxxx>
---
arch/ia64/xen/xenentry.S | 798 +++++++++++++++++++++++++++++++++++++++++
include/asm-ia64/xen/privop.h | 22 ++
2 files changed, 820 insertions(+), 0 deletions(-)
create mode 100644 arch/ia64/xen/xenentry.S
diff --git a/arch/ia64/xen/xenentry.S b/arch/ia64/xen/xenentry.S
new file mode 100644
index 0000000..38a509d
--- /dev/null
+++ b/arch/ia64/xen/xenentry.S
@@ -0,0 +1,798 @@
+/*
+ * ia64/xen/entry.S
+ *
+ * Alternate kernel routines for Xen. Heavily leveraged from
+ * ia64/kernel/entry.S
+ *
+ * Copyright (C) 2005 Hewlett-Packard Co
+ * Dan Magenheimer <dan.magenheimer@.hp.com>
+ */
+
+#include <asm/asmmacro.h>
+#include <asm/cache.h>
+#include <asm/errno.h>
+#include <asm/kregs.h>
+#include <asm/asm-offsets.h>
+#include <asm/pgtable.h>
+#include <asm/percpu.h>
+#include <asm/processor.h>
+#include <asm/thread_info.h>
+#include <asm/unistd.h>
+
+#ifdef CONFIG_XEN
+#include "xenminstate.h"
+#include <asm/paravirt_nop.h>
+#else
+#include "minstate.h"
+#endif
+
+/*
+ * 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.
+ */
+#ifdef CONFIG_XEN
+GLOBAL_ENTRY(xen_switch_to)
+ BR_IF_NATIVE(__ia64_switch_to, r22, p7)
+#else
+GLOBAL_ENTRY(ia64_switch_to)
+#endif
+ .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
+#ifdef CONFIG_XEN
+ // update "current" application register
+ mov r8=IA64_KR_CURRENT
+ mov r9=in0;;
+ XEN_HYPER_SET_KR
+#else
+ mov IA64_KR(CURRENT)=in0 // update "current" application register
+#endif
+ 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:
+#ifdef CONFIG_XEN
+ movl r25=XSI_PSR_IC // clear psr.ic
+ ;;
+ st4 [r25]=r0
+ ;;
+#else
+ rsm psr.ic // interrupts (psr.i) are already
disabled here
+#endif
+ movl r25=PAGE_KERNEL
+ ;;
+ srlz.d
+ or r23=r25,r20 // construct PA | page properties
+ mov r25=IA64_GRANULE_SHIFT<<2
+ ;;
+#ifdef CONFIG_XEN
+ movl r8=XSI_ITIR
+ ;;
+ st8 [r8]=r25
+ ;;
+ movl r8=XSI_IFA
+ ;;
+ st8 [r8]=in0 // VA of next task...
+ ;;
+ mov r25=IA64_TR_CURRENT_STACK
+ // remember last page we mapped...
+ mov r8=IA64_KR_CURRENT_STACK
+ mov r9=r26;;
+ XEN_HYPER_SET_KR;;
+#else
+ 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...
+#endif
+ ;;
+ itr.d dtr[r25]=r23 // wire in new mapping...
+#ifdef CONFIG_XEN
+ ;;
+ srlz.d
+ mov r9=1
+ movl r8=XSI_PSR_IC
+ ;;
+ st4 [r8]=r9
+ ;;
+#else
+ ssm psr.ic // reenable the psr.ic bit
+ ;;
+ srlz.d
+#endif
+ br.cond.sptk .done
+#ifdef CONFIG_XEN
+END(xen_switch_to)
+#else
+END(ia64_switch_to)
+#endif
+
+#ifdef CONFIG_XEN
+GLOBAL_ENTRY(xen_work_processed_syscall_with_check)
+ BR_IF_NATIVE(__ia64_work_processed_syscall, r2, p7)
+ br.cond.sptk xen_work_processed_syscall
+END(xen_work_processed_syscall_with_check)
+#endif
+
+/*
+ * 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
+ */
+#ifdef CONFIG_XEN
+GLOBAL_ENTRY(xen_leave_syscall)
+ BR_IF_NATIVE(__ia64_leave_syscall, r22, p7)
+#else
+ENTRY(ia64_leave_syscall)
+#endif
+ 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 */
+#ifdef CONFIG_XEN
+ movl r2=XSI_PSR_I_ADDR
+ mov r18=1
+ ;;
+ ld8 r2=[r2]
+ ;;
+(pUStk) st1 [r2]=r18
+#else
+(pUStk) rsm psr.i
+#endif
+ cmp.eq pLvSys,p0=r0,r0 // pLvSys=1: leave from syscall
+(pUStk) cmp.eq.unc p6,p0=r0,r0 // p6 <- pUStk
+#endif
+#ifdef CONFIG_XEN
+.global xen_work_processed_syscall;
+xen_work_processed_syscall:
+#else
+.work_processed_syscall:
+#endif
+ 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
+#ifdef CONFIG_XEN
+ movl r28=XSI_PSR_I_ADDR
+ movl r29=XSI_PSR_IC
+ ;;
+ ld8 r28=[r28]
+ mov r30=1
+ ;;
+ st1 [r28]=r30
+ st4 [r29]=r0 // note: clears both vpsr.i and vpsr.ic!
+ ;;
+#else
+ rsm psr.i | psr.ic // M2 turn off interrupts and interruption
collection
+#endif
+ 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
+#ifdef CONFIG_XEN
+(pKStk) mov r21=r8
+(pKStk) XEN_HYPER_GET_PSR
+ ;;
+(pKStk) mov r22=r8
+(pKStk) mov r8=r21
+ ;;
+#else
+(pKStk) mov r22=psr // M2 read PSR now that
interrupts are disabled
+#endif
+ 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
+#ifdef CONFIG_XEN
+ XEN_HYPER_COVER;
+#else
+ cover // B add current frame into dirty
partition & set cr.ifs
+#endif
+ ;;
+ 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
+#ifdef CONFIG_XEN
+END(xen_leave_syscall)
+#else
+END(ia64_leave_syscall)
+#endif
+
+#ifdef CONFIG_XEN
+GLOBAL_ENTRY(xen_leave_kernel)
+ BR_IF_NATIVE(__ia64_leave_kernel, r22, p7)
+#else
+GLOBAL_ENTRY(ia64_leave_kernel)
+#endif
+ 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
+#ifdef CONFIG_XEN
+(pUStk) movl r17=XSI_PSR_I_ADDR
+(pUStk) mov r31=1
+ ;;
+(pUStk) ld8 r17=[r17]
+ ;;
+(pUStk) st1 [r17]=r31
+ ;;
+#else
+(pUStk) rsm psr.i
+#endif
+ 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
+ ;;
+#ifdef CONFIG_XEN
+ movl r23=XSI_PSR_I_ADDR
+ movl r22=XSI_PSR_IC
+ ;;
+ ld8 r23=[r23]
+ mov r25=1
+ ;;
+ st1 [r23]=r25
+ st4 [r22]=r0 // note: clears both vpsr.i and vpsr.ic!
+ ;;
+#else
+ rsm psr.i | psr.ic // initiate turning off of interrupt and
interruption collection
+#endif
+ 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]
+#ifdef CONFIG_XEN
+ ;;
+ // r16-r31 all now hold bank1 values
+ mov r15=ar.unat
+ movl r2=XSI_BANK1_R16
+ movl r3=XSI_BANK1_R16+8
+ ;;
+.mem.offset 0,0; st8.spill [r2]=r16,16
+.mem.offset 8,0; st8.spill [r3]=r17,16
+ ;;
+.mem.offset 0,0; st8.spill [r2]=r18,16
+.mem.offset 8,0; st8.spill [r3]=r19,16
+ ;;
+.mem.offset 0,0; st8.spill [r2]=r20,16
+.mem.offset 8,0; st8.spill [r3]=r21,16
+ ;;
+.mem.offset 0,0; st8.spill [r2]=r22,16
+.mem.offset 8,0; st8.spill [r3]=r23,16
+ ;;
+.mem.offset 0,0; st8.spill [r2]=r24,16
+.mem.offset 8,0; st8.spill [r3]=r25,16
+ ;;
+.mem.offset 0,0; st8.spill [r2]=r26,16
+.mem.offset 8,0; st8.spill [r3]=r27,16
+ ;;
+.mem.offset 0,0; st8.spill [r2]=r28,16
+.mem.offset 8,0; st8.spill [r3]=r29,16
+ ;;
+.mem.offset 0,0; st8.spill [r2]=r30,16
+.mem.offset 8,0; st8.spill [r3]=r31,16
+ ;;
+ mov r3=ar.unat
+ movl r2=XSI_B1NAT
+ ;;
+ st8 [r2]=r3
+ mov ar.unat=r15
+ movl r2=XSI_BANKNUM;;
+ st4 [r2]=r0;
+#else
+ bsw.0 // switch back to bank 0 (no stop bit required
beforehand...)
+#endif
+ ;;
+(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
+
+#ifdef CONFIG_XEN
+(pKStk) mov r29=r8
+(pKStk) XEN_HYPER_GET_PSR
+ ;;
+(pKStk) mov r22=r8
+(pKStk) mov r8=r29
+ ;;
+#else
+(pKStk) mov r22=psr // M2 read PSR now that interrupts are
disabled
+#endif
+ 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
+
+#ifdef CONFIG_XEN
+ XEN_HYPER_COVER;
+#else
+ cover // add current frame into dirty
partition and set cr.ifs
+#endif
+ ;;
+ 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
+ ;;
+#ifdef CONFIG_XEN
+ movl r25=XSI_IPSR
+ ;;
+ st8[r25]=r29,XSI_IFS_OFS-XSI_IPSR_OFS
+ ;;
+#else
+ mov cr.ipsr=r29 // M2
+#endif
+ mov ar.pfs=r26 // I0
+(pLvSys)mov r17=r0 // A clear r17 for leave_syscall, no-op
otherwise
+
+#ifdef CONFIG_XEN
+(p9) st8 [r25]=r30
+ ;;
+ adds r25=XSI_IIP_OFS-XSI_IFS_OFS,r25
+ ;;
+#else
+(p9) mov cr.ifs=r30 // M2
+#endif
+ mov b0=r21 // I0
+(pLvSys)mov r18=r0 // A clear r18 for leave_syscall, no-op
otherwise
+
+ mov ar.fpsr=r20 // M2
+#ifdef CONFIG_XEN
+ st8 [r25]=r28
+#else
+ mov cr.iip=r28 // M2
+#endif
+ 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
+#ifdef CONFIG_XEN
+ ;;
+ XEN_HYPER_RFI;
+#else
+ rfi // B
+#endif
+
+ /*
+ * On entry:
+ * r20 = ¤t->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
+#ifdef CONFIG_XEN
+ movl r2=XSI_PSR_I_ADDR
+ mov r20=1
+ ;;
+ ld8 r2=[r2]
+ ;;
+ st1 [r2]=r20
+#else
+ rsm psr.i // disable interrupts
+#endif
+ ;;
+#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]
+#ifdef CONFIG_XEN
+ br.cond.sptk.many xen_work_processed_syscall // re-check
+#else
+ br.cond.sptk.many .work_processed_syscall // re-check
+#endif
+
+#ifdef CONFIG_XEN
+END(xen_leave_kernel)
+#else
+END(ia64_leave_kernel)
+#endif
diff --git a/include/asm-ia64/xen/privop.h b/include/asm-ia64/xen/privop.h
index dd3e5ec..c8a5a0d 100644
--- a/include/asm-ia64/xen/privop.h
+++ b/include/asm-ia64/xen/privop.h
@@ -70,4 +70,26 @@
#define XSI_IHA (XSI_BASE + XSI_IHA_OFS)
#endif
+/* these routines utilize privilege-sensitive or performance-sensitive
+ * privileged instructions so the code must be replaced with
+ * paravirtualized versions */
+#ifndef CONFIG_PARAVIRT_ENTRY
+#define IA64_PARAVIRTUALIZED_ENTRY
+#define ia64_switch_to xen_switch_to
+#define ia64_leave_syscall xen_leave_syscall
+#define ia64_work_processed_syscall xen_work_processed_syscall_with_check
+#define ia64_leave_kernel xen_leave_kernel
+#endif /* !CONFIG_PARAVIRT_ENTRY */
+
+#ifdef CONFIG_XEN
+#ifdef __ASSEMBLY__
+#define BR_IF_NATIVE(target, reg, pred) \
+ .body ; \
+ movl reg=running_on_xen;; ; \
+ ld4 reg=[reg];; ; \
+ cmp.eq pred,p0=reg,r0 ; \
+ (pred) br.cond.sptk.many target;;
+#endif /* __ASSEMBLY__ */
+#endif
+
#endif /* _ASM_IA64_XEN_PRIVOP_H */
--
1.5.3
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