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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-ia64-devel] pv_ops: entry.S simplification
Hi Eddie.
I looked into entry.S closely.
Unfortunately I found that ia64_leave_syscall() and
ia64_leave_kernel() includes invirtualizable instructions,
cover instruction with psr.ic = 0 so that those paravirtualization
is inevitable. (ia64_switch_to() doesn't need paravirtualization though.)
Does it really work? Probably "just seeing login prompt test" doesn't
reveal the issues.
thanks,
On Wed, Mar 19, 2008 at 05:53:54PM +0800, Dong, Eddie wrote:
> Entry.S have several sensitive instruction touch and is dual compiled
> for now,
> which lead to 2-3K lines of patch in total. This patch simplify it by
> leaving it
> to future after we get basic domU support patch into upstream.
>
>
> commit be212435e23d1c7527e7637f0b6faf91099f8c61
> Author: root <root@xxxxxxxxxxxxxxxxxxxxxx>
> Date: Wed Mar 19 17:33:08 2008 +0800
>
> remove entry.S dual compile for now to reduce several K
> line of patch. Will revisit later.
>
> Signed-off-by: Yaozu (Eddie) Dong <eddie.dong@xxxxxxxxx>
>
> diff --git a/arch/ia64/kernel/Makefile b/arch/ia64/kernel/Makefile
> index b912d3d..3e9a162 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 switch_leave.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 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
> @@ -36,8 +36,7 @@ obj-$(CONFIG_PCI_MSI) += msi_ia64.o
> mca_recovery-y += mca_drv.o mca_drv_asm.o
> obj-$(CONFIG_IA64_MC_ERR_INJECT)+= err_inject.o
>
> -obj-$(CONFIG_PARAVIRT) += paravirt_core.o paravirt_entry.o \
> - paravirtentry.o
> +obj-$(CONFIG_PARAVIRT) += paravirt_core.o paravirt_entry.o
>
> obj-$(CONFIG_PARAVIRT_GUEST) += paravirt.o
>
> @@ -77,22 +76,20 @@ $(obj)/gate-syms.o: $(obj)/gate.lds $(obj)/gate.o
> FORCE
> $(obj)/gate-data.o: $(obj)/gate.so
>
> #
> -# native ivt.S and switch_leave.S
> +# native ivt.S
> #
> AFLAGS_ivt.o += -D__IA64_ASM_PARAVIRTUALIZED_NATIVE
> -AFLAGS_switch_leave.o += -D__IA64_ASM_PARAVIRTUALIZED_NATIVE
>
> # xen multi compile
> $(obj)/xen_%.o: $(src)/%.S FORCE
> $(call if_changed_dep,as_o_S)
>
> #
> -# xenivt.o, xen_switch_leave.o
> +# xenivt.o
> #
> -obj-$(CONFIG_XEN) += xen_ivt.o xen_switch_leave.o
> +obj-$(CONFIG_XEN) += xen_ivt.o
> ifeq ($(CONFIG_XEN), y)
> -targets += xen_ivt.o xen_switch_leave.o
> -$(obj)/build-in.o: xen_ivt.o xen_switch_leave.o
> +targets += xen_ivt.o
> +$(obj)/build-in.o: xen_ivt.o
> endif
> AFLAGS_xen_ivt.o += -D__IA64_ASM_PARAVIRTUALIZED_XEN
> -AFLAGS_xen_switch_leave.o += -D__IA64_ASM_PARAVIRTUALIZED_XEN
> diff --git a/arch/ia64/kernel/entry.S b/arch/ia64/kernel/entry.S
> index de91f61..7b803f0 100644
> --- a/arch/ia64/kernel/entry.S
> +++ b/arch/ia64/kernel/entry.S
> @@ -14,6 +14,15 @@
> * Copyright (C) 1999 Walt Drummond <drummond@xxxxxxxxxxx>
> */
> /*
> + * 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@xxxxxxxxxxxxxxxxxxxxxxxx>
> + * Patrick O'Rourke <orourke@xxxxxxxxxxxxxxxxxxxxxxxx>
> + * 11/07/2000
> + */
> +/*
> * Global (preserved) predicate usage on syscall entry/exit path:
> *
> * pKStk: See entry.h.
> @@ -33,6 +42,7 @@
> #include <asm/processor.h>
> #include <asm/thread_info.h>
> #include <asm/unistd.h>
> +#include <asm/xen/interface.h>
>
> #include "minstate.h"
>
> @@ -166,6 +176,68 @@ 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,
> @@ -304,7 +376,7 @@ END(save_switch_stack)
> * - b7 holds address to return to
> * - must not touch r8-r11
> */
> -GLOBAL_ENTRY(load_switch_stack)
> +ENTRY(load_switch_stack)
> .prologue
> .altrp b7
>
> @@ -499,7 +571,7 @@ 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 ia64_work_pending_syscall_end
> + br.cond.sptk .work_pending_syscall_end
>
> strace_error:
> ld8 r3=[r2] // load pt_regs.r8
> @@ -564,10 +636,172 @@ 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
> ;;
> - br.cond.sptk.few ia64_leave_syscall
> +(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
> ;;
> -END(ia64_ret_from_syscall)
> + 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
> + /*
> + * TODO:
> + * Use indirect pv_ops call or dual compile in future.
> + */
> + movl r19=running_on_xen;;
> + ld4 r19=[r19];;
> + cmp.ne p9,p0=r19,r0;;
> +(p9) break HYPERPRIVOP_COVER;; // running_on_xen
> +(p9) br.cond.dpnt.many _skip_cover;;
> + cover // !running_on_xen
> + ;;
> +_skip_cover:
> +
> + ;;
> + 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)
>
> #ifdef CONFIG_IA32_SUPPORT
> GLOBAL_ENTRY(ia64_ret_from_ia32_execve)
> @@ -579,12 +813,366 @@ 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
> - ;;
> - // don't fall through, ia64_leave_kernel may be #define'd
> - br.cond.sptk.few ia64_leave_kernel
> - ;;
> 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
> + ;;
> + 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
> + /*
> + * TODO:
> + * Use indirect pv_ops call or dual compile in future.
> + */
> + movl r19=running_on_xen;;
> + ld4 r19=[r19];;
> + cmp.ne p9,p0=r19,r0;;
> +(p9) break HYPERPRIVOP_COVER;; // running_on_xen
> +(p9) br.cond.dpnt.many _skip_cover2;;
> + cover // !running_on_xen
> + ;;
> +_skip_cover2:
> +
> + ;;
> + 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
> +
> + /*
> + * TODO:
> + * Sounds like a bug in Xen for RFI slow patch emulation.
> + */
> + movl r19=running_on_xen;;
> + ld4 r19=[r19];;
> + cmp.ne p9,p0=r19,r0;;
> +(p9) br.cond.dpnt.many rfi_guest;; // running_on_xen
> +
> + mov ar.rsc=r27 // M2
> + mov pr=r31,-1 // I0
> + rfi // B
> +
> +rfi_guest:
> + mov ar.rsc=r27 // M2
> + mov pr=r31,-1 // I0
> + break HYPERPRIVOP_RFI
> + dv_serialize_data
> +
> + /*
> + * 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
> + 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)
>
> ENTRY(handle_syscall_error)
> /*
> @@ -624,7 +1212,7 @@ END(ia64_invoke_schedule_tail)
> * be set up by the caller. We declare 8 input registers so the
> system call
> * args get preserved, in case we need to restart a system call.
> */
> -GLOBAL_ENTRY(notify_resume_user)
> +ENTRY(notify_resume_user)
> .prologue ASM_UNW_PRLG_RP|ASM_UNW_PRLG_PFS,
> ASM_UNW_PRLG_GRSAVE(8)
> alloc loc1=ar.pfs,8,2,3,0 // preserve all eight input regs in
> case of syscall restart!
> mov r9=ar.unat
> @@ -686,7 +1274,7 @@ ENTRY(sys_rt_sigreturn)
> adds sp=16,sp
> ;;
> ld8 r9=[sp] // load new ar.unat
> - mov b7=r8
> + mov.sptk b7=r8,ia64_leave_kernel
> ;;
> mov ar.unat=r9
> br.many b7
> diff --git a/arch/ia64/xen/paravirt_xen.c b/arch/ia64/xen/paravirt_xen.c
> index 5670c4a..aa12cb5 100644
> --- a/arch/ia64/xen/paravirt_xen.c
> +++ b/arch/ia64/xen/paravirt_xen.c
> @@ -24,16 +24,7 @@
> #include <asm/paravirt_core.h>
> #include <asm/paravirt_entry.h>
>
> -extern void *xen_switch_to;
> -extern void *xen_leave_syscall;
> -extern void *xen_leave_kernel;
> -extern void *xen_work_processed_syscall;
> -
> const static struct paravirt_entry xen_entries[] __initdata = {
> - {&xen_switch_to, PARAVIRT_ENTRY_SWITCH_TO},
> - {&xen_leave_syscall, PARAVIRT_ENTRY_LEAVE_SYSCALL},
> - {&xen_leave_kernel, PARAVIRT_ENTRY_LEAVE_KERNEL},
> - {&xen_work_processed_syscall,
> PARAVIRT_ENTRY_WORK_PROCESSED_SYSCALL},
> };
>
> void __init
> diff --git a/include/asm-ia64/native/inst.h
> b/include/asm-ia64/native/inst.h
> index 0ecc06e..7e91396 100644
> --- a/include/asm-ia64/native/inst.h
> +++ b/include/asm-ia64/native/inst.h
> @@ -35,14 +35,6 @@
> # define CLOBBER(clob) /* nothing */
> #endif
>
> -#define __paravirt_switch_to ia64_native_switch_to
> -#define __paravirt_leave_syscall
> ia64_native_leave_syscall
> -#define __paravirt_work_processed_syscall
> ia64_native_work_processed_syscall
> -#define __paravirt_leave_kernel
> ia64_native_leave_kernel
> -#define __paravirt_pending_syscall_end
> ia64_work_pending_syscall_end
> -#define __paravirt_work_processed_syscall_target \
> -
> ia64_work_processed_syscall
> -
> #define MOV_FROM_IFA(reg) \
> mov reg = cr.ifa
>
> diff --git a/include/asm-ia64/privop.h b/include/asm-ia64/privop.h
> index ba02419..d4ac7af 100644
> --- a/include/asm-ia64/privop.h
> +++ b/include/asm-ia64/privop.h
> @@ -55,11 +55,6 @@
> #define ia64_set_rr0_to_rr4 ia64_native_set_rr0_to_rr4
> #endif /* !__ASSEMBLY */
>
> -#define ia64_switch_to ia64_native_switch_to
> -#define ia64_leave_syscall ia64_native_leave_syscall
> -#define ia64_work_processed_syscall
> ia64_native_work_processed_syscall
> -#define ia64_leave_kernel ia64_native_leave_kernel
> -
> #endif /* CONFIG_PARAVIRT */
>
> #endif /* _ASM_IA64_PRIVOP_H */
> diff --git a/include/asm-ia64/privop_paravirt.h
> b/include/asm-ia64/privop_paravirt.h
> index 11d65b1..c37e4ad 100644
> --- a/include/asm-ia64/privop_paravirt.h
> +++ b/include/asm-ia64/privop_paravirt.h
> @@ -25,13 +25,6 @@
>
> #ifdef CONFIG_PARAVIRT
>
> -/*
> - * struct task_struct* (*ia64_switch_to)(void* next_task);
> - * void *ia64_leave_syscall;
> - * void *ia64_work_processed_syscall
> - * void *ia64_leave_kernel;
> - */
> -
> #define PARAVIRT_ENTRY_START 0x20000000
> #define PARAVIRT_ENTRY_SWITCH_TO (PARAVIRT_ENTRY_START +
> 0)
> #define PARAVIRT_ENTRY_LEAVE_SYSCALL (PARAVIRT_ENTRY_START +
> 1)
> @@ -368,10 +361,6 @@ paravirt_rsm(unsigned long mask)
> /* these routines utilize privilege-sensitive or performance-sensitive
> * privileged instructions so the code must be replaced with
> * paravirtualized versions */
> -#define ia64_switch_to paravirt_switch_to
> -#define ia64_work_processed_syscall paravirt_work_processed_syscall
> -#define ia64_leave_syscall paravirt_leave_syscall
> -#define ia64_leave_kernel paravirt_leave_kernel
>
> #endif /* CONFIG_PARAVIRT */
>
> diff --git a/include/asm-ia64/xen/inst.h b/include/asm-ia64/xen/inst.h
> index 45d9a42..a8fb2ac 100644
> --- a/include/asm-ia64/xen/inst.h
> +++ b/include/asm-ia64/xen/inst.h
> @@ -24,12 +24,9 @@
>
> #define ia64_ivt xen_ivt
>
> -#define __paravirt_switch_to xen_switch_to
> -#define __paravirt_leave_syscall xen_leave_syscall
> -#define __paravirt_work_processed_syscall
> xen_work_processed_syscall
> -#define __paravirt_leave_kernel xen_leave_kernel
> -#define __paravirt_pending_syscall_end
> xen_work_pending_syscall_end
> -#define __paravirt_work_processed_syscall_target \
> +//#define __paravirt_work_processed_syscall
> xen_work_processed_syscall
> +//#define __paravirt_pending_syscall_end
> xen_work_pending_syscall_end
> +//#define __paravirt_work_processed_syscall_target \
>
> xen_work_processed_syscall
>
> #define MOV_FROM_IFA(reg) \
> _______________________________________________
> Xen-ia64-devel mailing list
> Xen-ia64-devel@xxxxxxxxxxxxxxxxxxx
> http://lists.xensource.com/xen-ia64-devel
--
yamahata
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