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[IA64] Schedule ia64_leave_syscall() to read ar.bsp earlier

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Reschedule code to read ar.bsp as early as possible.  To enable this,
don't bother clearing some of the registers when we're returning to
kernel stacks.  Also, instead of trying to support the pNonSys case
(which makes no sense), do a bugcheck instead (with break 0).  Finally,
remove a clear of r14 which is a left-over from the previous patch.

Signed-off-by: David Mosberger-Tang <davidm@hpl.hp.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
This commit is contained in:
David Mosberger-Tang 2005-04-27 21:17:44 -07:00 committed by Tony Luck
parent 060561ff79
commit 87e522a0f7
1 changed files with 19 additions and 24 deletions
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43
arch/ia64/kernel/entry.S
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@ -694,22 +694,22 @@ ENTRY(ia64_leave_syscall)
ld8 r19=[r2],PT(B6)-PT(LOADRS) // load ar.rsc value for "loadrs"
nop.i 0
;;
ld8 r23=[r3],PT(R11)-PT(AR_BSPSTORE) // load ar.bspstore (may be garbage)
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?
;;
mov r16=ar.bsp // M2 get existing backing store pointer
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)
nop.i 0
(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 initiate turning off of interrupt and interruption collection
nop.i 0
cmp.eq p9,p0=r0,r0 // set p9 to indicate that we should restore cr.ifs
ld8 r29=[r2],16 // load cr.ipsr
ld8 r28=[r3],16 // load cr.iip
@ -717,11 +717,11 @@ ENTRY(ia64_leave_syscall)
;;
ld8 r30=[r2],16 // M0|1 load cr.ifs
ld8 r25=[r3],16 // M0|1 load ar.unat
cmp.eq p9,p0=r0,r0 // set p9 to indicate that we should restore cr.ifs
(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
(pUStk) add r14=IA64_TASK_THREAD_ON_USTACK_OFFSET,r13
nop 0
;;
ld8 r21=[r2],PT(AR_RNAT)-PT(B0) // load b0
ld8 r27=[r3],PT(PR)-PT(AR_RSC) // load ar.rsc
@ -735,40 +735,35 @@ ENTRY(ia64_leave_syscall)
ld8.fill r1=[r3],16 // load r1
(pUStk) mov r17=1
;;
srlz.d // M0 ensure interruption collection is off
(pUStk) st1 [r14]=r17
ld8.fill r13=[r3],16
mov f8=f0 // clear f8
;;
ld8.fill r12=[r2] // restore r12 (sp)
mov.m ar.ssd=r0 // M2 clear ar.ssd
ld8.fill r15=[r3] // restore r15
mov b6=r18 // I0 restore b6
nop.m 0
addl r17=THIS_CPU(ia64_phys_stacked_size_p8),r0
mov f9=f0 // clear f9
(pKStk) br.cond.dpnt.many skip_rbs_switch
srlz.d // M0 ensure interruption collection is off
shr.u r18=r19,16 // I0|1 get byte size of existing "dirty" partition
cover // B add current frame into dirty partition and set cr.ifs
;;
ld8.fill r15=[r3] // restore r15
(pUStk) st1 [r14]=r17
addl r3=THIS_CPU(ia64_phys_stacked_size_p8),r0
;;
(pUStk) ld4 r17=[r3] // r17 = cpu_data->phys_stacked_size_p8
mov.m ar.csd=r0 // M2 clear ar.csd
(pUStk) ld4 r17=[r17] // r17 = cpu_data->phys_stacked_size_p8
mov r19=ar.bsp // M2 get new backing store pointer
mov f10=f0 // clear f10
nop.m 0
movl r14=__kernel_syscall_via_epc // X
;;
nop.m 0
nop.m 0
mov.m ar.csd=r0 // M2 clear ar.csd
mov.m ar.ccv=r0 // clear ar.ccv
mov b7=r14 // I0 clear b7 (hint with __kernel_syscall_via_epc)
mov r14=r0 // clear r14
mov.m ar.ssd=r0 // M2 clear ar.ssd
mov f11=f0 // clear f11
(pKStk) br.cond.dpnt.many skip_rbs_switch
mov.m ar.ccv=r0 // clear ar.ccv
(pNonSys) br.cond.dpnt.many dont_preserve_current_frame
br.cond.sptk.many rbs_switch
END(ia64_leave_syscall)
@ -946,10 +941,10 @@ GLOBAL_ENTRY(ia64_leave_kernel)
*/
(pNonSys) br.cond.dpnt dont_preserve_current_frame
rbs_switch:
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
;;