/* $Id$ * 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 #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_notify_resume, 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 + TI_FLAGS], %l0 andcc %l0, _TIF_NEED_RESCHED, %g0 be,pt %xcc, 1f nop call schedule wrpr %g0, RTRAP_PSTATE, %pstate wrpr %g0, RTRAP_PSTATE_IRQOFF, %pstate ldx [%g6 + TI_FLAGS], %l0 1: andcc %l0, (_TIF_NOTIFY_RESUME | _TIF_SIGPENDING), %g0 be,pt %xcc, __handle_user_windows_continue nop clr %o0 mov %l5, %o2 mov %l6, %o3 add %sp, PTREGS_OFF, %o1 mov %l0, %o4 call do_notify_resume 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 + TI_WSAVED], %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 ldx [%g6 + TI_FLAGS], %l0 andcc %l0, _TIF_NEED_RESCHED, %g0 be,pt %xcc, 1f nop call schedule wrpr %g0, RTRAP_PSTATE, %pstate wrpr %g0, RTRAP_PSTATE_IRQOFF, %pstate ldx [%g6 + TI_FLAGS], %l0 1: andcc %l0, (_TIF_NOTIFY_RESUME | _TIF_SIGPENDING), %g0 be,pt %xcc, __handle_perfctrs_continue sethi %hi(TSTATE_PEF), %o0 clr %o0 mov %l5, %o2 mov %l6, %o3 add %sp, PTREGS_OFF, %o1 mov %l0, %o4 call do_notify_resume 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, PTREGS_OFF, %o1 mov %l0, %o4 call do_notify_resume 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_irq, rtrap_clr_l6, rtrap, irqsz_patchme, rtrap_xcall rtrap_irq: rtrap_clr_l6: clr %l6 rtrap: #ifndef CONFIG_SMP sethi %hi(per_cpu____cpu_data), %l0 lduw [%l0 + %lo(per_cpu____cpu_data)], %l1 #else sethi %hi(per_cpu____cpu_data), %l0 or %l0, %lo(per_cpu____cpu_data), %l0 lduw [%l0 + %g5], %l1 #endif 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 wrpr 0, %pil __handle_preemption_continue: ldx [%g6 + TI_FLAGS], %l0 sethi %hi(_TIF_USER_WORK_MASK), %o0 or %o0, %lo(_TIF_USER_WORK_MASK), %o0 andcc %l0, %o0, %g0 sethi %hi(TSTATE_PEF), %o0 be,pt %xcc, user_nowork andcc %l1, %o0, %g0 andcc %l0, _TIF_NEED_RESCHED, %g0 bne,pn %xcc, __handle_preemption andcc %l0, (_TIF_NOTIFY_RESUME | _TIF_SIGPENDING), %g0 bne,pn %xcc, __handle_signal __handle_signal_continue: ldub [%g6 + TI_WSAVED], %o2 brnz,pn %o2, __handle_user_windows nop __handle_user_windows_continue: ldx [%g6 + TI_FLAGS], %l5 andcc %l5, _TIF_PERFCTR, %g0 sethi %hi(TSTATE_PEF), %o0 bne,pn %xcc, __handle_perfctrs __handle_perfctrs_continue: andcc %l1, %o0, %g0 /* This fpdepth clear is necessary for non-syscall rtraps only */ user_nowork: bne,pn %xcc, __handle_userfpu stb %g0, [%g6 + TI_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 mov TSB_REG, %g6 brnz,a,pn %l3, 1f ldxa [%g6] ASI_IMMU, %g5 1: 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 sethi %hi(sparc64_kern_pri_nuc_bits), %l1 ldx [%l1 + %lo(sparc64_kern_pri_nuc_bits)], %l1 or %l0, %l1, %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: #ifdef CONFIG_PREEMPT ldsw [%g6 + TI_PRE_COUNT], %l5 brnz %l5, kern_fpucheck ldx [%g6 + TI_FLAGS], %l5 andcc %l5, _TIF_NEED_RESCHED, %g0 be,pt %xcc, kern_fpucheck srl %l4, 20, %l5 cmp %l5, 0 bne,pn %xcc, kern_fpucheck sethi %hi(PREEMPT_ACTIVE), %l6 stw %l6, [%g6 + TI_PRE_COUNT] call schedule nop ba,pt %xcc, rtrap stw %g0, [%g6 + TI_PRE_COUNT] #endif kern_fpucheck: ldub [%g6 + TI_FPDEPTH], %l5 brz,pt %l5, rt_continue srl %l5, 1, %o0 add %g6, TI_FPSAVED, %l6 ldub [%l6 + %o0], %l2 sub %l5, 2, %l5 add %g6, TI_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, %g1 wr %g1, FPRS_FEF, %fprs ldx [%o1 + %o5], %g1 add %g6, TI_XFSR, %o1 sll %o0, 8, %o2 add %g6, TI_FPREGS, %o3 brz,pn %l6, 1f add %g6, TI_FPREGS+0x40, %o4 membar #Sync ldda [%o3 + %o2] ASI_BLK_P, %f0 ldda [%o4 + %o2] ASI_BLK_P, %f16 membar #Sync 1: andcc %l2, FPRS_DU, %g0 be,pn %icc, 1f wr %g1, 0, %gsr add %o2, 0x80, %o2 membar #Sync 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 + TI_FPDEPTH] ba,pt %xcc, rt_continue nop 5: wr %g0, FPRS_FEF, %fprs sll %o0, 8, %o2 add %g6, TI_FPREGS+0x80, %o3 add %g6, TI_FPREGS+0xc0, %o4 membar #Sync 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 + TI_FPDEPTH]