/* $Id: rtrap.S,v 1.57.2.2 2002/03/03 10:31:56 davem Exp $ * rtrap.S: Preparing for return from trap on Sparc V9. * * Copyright (C) 1997,1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz) * Copyright (C) 1997 David S. Miller (davem@caip.rutgers.edu) */ #include #include #include #include #include #include #include #define RTRAP_PSTATE (PSTATE_RMO|PSTATE_PEF|PSTATE_PRIV|PSTATE_IE) #define RTRAP_PSTATE_IRQOFF (PSTATE_RMO|PSTATE_PEF|PSTATE_PRIV) #define RTRAP_PSTATE_AG_IRQOFF (PSTATE_RMO|PSTATE_PEF|PSTATE_PRIV|PSTATE_AG) /* Register %l6 keeps track of whether we are returning * from a system call or not. It is cleared if we call * do_signal, and it must not be otherwise modified until * we fully commit to returning to userspace. */ .text .align 32 __handle_softirq: call do_softirq nop ba,a,pt %xcc, __handle_softirq_continue nop __handle_preemption: call schedule wrpr %g0, RTRAP_PSTATE, %pstate ba,pt %xcc, __handle_preemption_continue wrpr %g0, RTRAP_PSTATE_IRQOFF, %pstate __handle_user_windows: call fault_in_user_windows wrpr %g0, RTRAP_PSTATE, %pstate wrpr %g0, RTRAP_PSTATE_IRQOFF, %pstate /* Redo sched+sig checks */ ldx [%g6 + AOFF_task_need_resched], %l0 brz,pt %l0, 1f nop call schedule wrpr %g0, RTRAP_PSTATE, %pstate wrpr %g0, RTRAP_PSTATE_IRQOFF, %pstate 1: lduw [%g6 + AOFF_task_sigpending], %l0 brz,pt %l0, __handle_user_windows_continue nop clr %o0 mov %l5, %o2 mov %l6, %o3 add %sp, STACK_BIAS + REGWIN_SZ, %o1 call do_signal wrpr %g0, RTRAP_PSTATE, %pstate wrpr %g0, RTRAP_PSTATE_IRQOFF, %pstate clr %l6 /* Signal delivery can modify pt_regs tstate, so we must * reload it. */ ldx [%sp + PTREGS_OFF + PT_V9_TSTATE], %l1 sethi %hi(0xf << 20), %l4 and %l1, %l4, %l4 ba,pt %xcc, __handle_user_windows_continue andn %l1, %l4, %l1 __handle_perfctrs: call update_perfctrs wrpr %g0, RTRAP_PSTATE, %pstate wrpr %g0, RTRAP_PSTATE_IRQOFF, %pstate ldub [%g6 + AOFF_task_thread + AOFF_thread_w_saved], %o2 brz,pt %o2, 1f nop /* Redo userwin+sched+sig checks */ call fault_in_user_windows wrpr %g0, RTRAP_PSTATE, %pstate wrpr %g0, RTRAP_PSTATE_IRQOFF, %pstate 1: ldx [%g6 + AOFF_task_need_resched], %l0 brz,pt %l0, 1f nop call schedule wrpr %g0, RTRAP_PSTATE, %pstate wrpr %g0, RTRAP_PSTATE_IRQOFF, %pstate 1: lduw [%g6 + AOFF_task_sigpending], %l0 brz,pt %l0, __handle_perfctrs_continue sethi %hi(TSTATE_PEF), %o0 clr %o0 mov %l5, %o2 mov %l6, %o3 add %sp, STACK_BIAS + REGWIN_SZ, %o1 call do_signal wrpr %g0, RTRAP_PSTATE, %pstate wrpr %g0, RTRAP_PSTATE_IRQOFF, %pstate clr %l6 /* Signal delivery can modify pt_regs tstate, so we must * reload it. */ ldx [%sp + PTREGS_OFF + PT_V9_TSTATE], %l1 sethi %hi(0xf << 20), %l4 and %l1, %l4, %l4 andn %l1, %l4, %l1 ba,pt %xcc, __handle_perfctrs_continue sethi %hi(TSTATE_PEF), %o0 __handle_userfpu: rd %fprs, %l5 andcc %l5, FPRS_FEF, %g0 sethi %hi(TSTATE_PEF), %o0 be,a,pn %icc, __handle_userfpu_continue andn %l1, %o0, %l1 ba,a,pt %xcc, __handle_userfpu_continue __handle_signal: clr %o0 mov %l5, %o2 mov %l6, %o3 add %sp, STACK_BIAS + REGWIN_SZ, %o1 call do_signal wrpr %g0, RTRAP_PSTATE, %pstate wrpr %g0, RTRAP_PSTATE_IRQOFF, %pstate clr %l6 /* Signal delivery can modify pt_regs tstate, so we must * reload it. */ ldx [%sp + PTREGS_OFF + PT_V9_TSTATE], %l1 sethi %hi(0xf << 20), %l4 and %l1, %l4, %l4 ba,pt %xcc, __handle_signal_continue andn %l1, %l4, %l1 .align 64 .globl rtrap_clr_l6, rtrap, irqsz_patchme, rtrap_xcall rtrap_clr_l6: clr %l6 rtrap: lduw [%g6 + AOFF_task_processor], %l0 sethi %hi(irq_stat), %l2 ! &softirq_active or %l2, %lo(irq_stat), %l2 ! &softirq_active irqsz_patchme: sllx %l0, 0, %l0 lduw [%l2 + %l0], %l1 ! softirq_pending cmp %l1, 0 /* mm/ultra.S:xcall_report_regs KNOWS about this load. */ bne,pn %icc, __handle_softirq ldx [%sp + PTREGS_OFF + PT_V9_TSTATE], %l1 __handle_softirq_continue: rtrap_xcall: sethi %hi(0xf << 20), %l4 andcc %l1, TSTATE_PRIV, %l3 and %l1, %l4, %l4 bne,pn %icc, to_kernel andn %l1, %l4, %l1 /* We must hold IRQs off and atomically test schedule+signal * state, then hold them off all the way back to userspace. * If we are returning to kernel, none of this matters. * * If we do not do this, there is a window where we would do * the tests, later the signal/resched event arrives but we do * not process it since we are still in kernel mode. It would * take until the next local IRQ before the signal/resched * event would be handled. * * This also means that if we have to deal with performance * counters or user windows, we have to redo all of these * sched+signal checks with IRQs disabled. */ to_user: wrpr %g0, RTRAP_PSTATE_IRQOFF, %pstate __handle_preemption_continue: ldx [%g6 + AOFF_task_need_resched], %l0 brnz,pn %l0, __handle_preemption lduw [%g6 + AOFF_task_sigpending], %l0 brnz,pn %l0, __handle_signal nop __handle_signal_continue: ldub [%g6 + AOFF_task_thread + AOFF_thread_w_saved], %o2 brnz,pn %o2, __handle_user_windows nop __handle_user_windows_continue: ldub [%g6 + AOFF_task_thread + AOFF_thread_flags], %l5 andcc %l5, SPARC_FLAG_PERFCTR, %g0 sethi %hi(TSTATE_PEF), %o0 bne,pn %xcc, __handle_perfctrs __handle_perfctrs_continue: andcc %l1, %o0, %g0 /* This fpdepth clear is neccessary for non-syscall rtraps only */ bne,pn %xcc, __handle_userfpu stb %g0, [%g6 + AOFF_task_thread + AOFF_thread_fpdepth] __handle_userfpu_continue: rt_continue: ldx [%sp + PTREGS_OFF + PT_V9_G1], %g1 ldx [%sp + PTREGS_OFF + PT_V9_G2], %g2 ldx [%sp + PTREGS_OFF + PT_V9_G3], %g3 ldx [%sp + PTREGS_OFF + PT_V9_G4], %g4 ldx [%sp + PTREGS_OFF + PT_V9_G5], %g5 ldx [%sp + PTREGS_OFF + PT_V9_G6], %g6 ldx [%sp + PTREGS_OFF + PT_V9_G7], %g7 wrpr %g0, RTRAP_PSTATE_AG_IRQOFF, %pstate ldx [%sp + PTREGS_OFF + PT_V9_I0], %i0 ldx [%sp + PTREGS_OFF + PT_V9_I1], %i1 ldx [%sp + PTREGS_OFF + PT_V9_I2], %i2 ldx [%sp + PTREGS_OFF + PT_V9_I3], %i3 ldx [%sp + PTREGS_OFF + PT_V9_I4], %i4 ldx [%sp + PTREGS_OFF + PT_V9_I5], %i5 ldx [%sp + PTREGS_OFF + PT_V9_I6], %i6 ldx [%sp + PTREGS_OFF + PT_V9_I7], %i7 ldx [%sp + PTREGS_OFF + PT_V9_TPC], %l2 ldx [%sp + PTREGS_OFF + PT_V9_TNPC], %o2 ld [%sp + PTREGS_OFF + PT_V9_Y], %o3 wr %o3, %g0, %y srl %l4, 20, %l4 wrpr %l4, 0x0, %pil wrpr %g0, 0x1, %tl wrpr %l1, %g0, %tstate wrpr %l2, %g0, %tpc wrpr %o2, %g0, %tnpc brnz,pn %l3, kern_rtt mov PRIMARY_CONTEXT, %l7 ldxa [%l7 + %l7] ASI_DMMU, %l0 stxa %l0, [%l7] ASI_DMMU flush %g6 rdpr %wstate, %l1 rdpr %otherwin, %l2 srl %l1, 3, %l1 wrpr %l2, %g0, %canrestore wrpr %l1, %g0, %wstate wrpr %g0, %g0, %otherwin restore rdpr %canrestore, %g1 wrpr %g1, 0x0, %cleanwin retry nop kern_rtt: restore retry to_kernel: ldub [%g6 + AOFF_task_thread + AOFF_thread_fpdepth], %l5 brz,pt %l5, rt_continue srl %l5, 1, %o0 add %g6, AOFF_task_thread + AOFF_thread_fpsaved, %l6 ldub [%l6 + %o0], %l2 sub %l5, 2, %l5 add %g6, AOFF_task_thread + AOFF_thread_gsr, %o1 andcc %l2, (FPRS_FEF|FPRS_DU), %g0 be,pt %icc, 2f and %l2, FPRS_DL, %l6 andcc %l2, FPRS_FEF, %g0 be,pn %icc, 5f sll %o0, 3, %o5 rd %fprs, %g5 wr %g5, FPRS_FEF, %fprs ldx [%o1 + %o5], %g5 add %g6, AOFF_task_thread + AOFF_thread_xfsr, %o1 membar #StoreLoad | #LoadLoad sll %o0, 8, %o2 add %g6, AOFF_task_fpregs, %o3 brz,pn %l6, 1f add %g6, AOFF_task_fpregs+0x40, %o4 ldda [%o3 + %o2] ASI_BLK_P, %f0 ldda [%o4 + %o2] ASI_BLK_P, %f16 1: andcc %l2, FPRS_DU, %g0 be,pn %icc, 1f wr %g5, 0, %gsr add %o2, 0x80, %o2 ldda [%o3 + %o2] ASI_BLK_P, %f32 ldda [%o4 + %o2] ASI_BLK_P, %f48 1: membar #Sync ldx [%o1 + %o5], %fsr 2: stb %l5, [%g6 + AOFF_task_thread + AOFF_thread_fpdepth] ba,pt %xcc, rt_continue nop 5: wr %g0, FPRS_FEF, %fprs membar #StoreLoad | #LoadLoad sll %o0, 8, %o2 add %g6, AOFF_task_fpregs+0x80, %o3 add %g6, AOFF_task_fpregs+0xc0, %o4 ldda [%o3 + %o2] ASI_BLK_P, %f32 ldda [%o4 + %o2] ASI_BLK_P, %f48 membar #Sync wr %g0, FPRS_DU, %fprs ba,pt %xcc, rt_continue stb %l5, [%g6 + AOFF_task_thread + AOFF_thread_fpdepth]