| /* SPDX-License-Identifier: GPL-2.0 */ |
| /* |
| * 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 <asm/asi.h> |
| #include <asm/pstate.h> |
| #include <asm/ptrace.h> |
| #include <asm/spitfire.h> |
| #include <asm/head.h> |
| #include <asm/visasm.h> |
| #include <asm/processor.h> |
| |
| #ifdef CONFIG_CONTEXT_TRACKING |
| # define SCHEDULE_USER schedule_user |
| #else |
| # define SCHEDULE_USER schedule |
| #endif |
| |
| .text |
| .align 32 |
| __handle_preemption: |
| call SCHEDULE_USER |
| 661: wrpr %g0, RTRAP_PSTATE, %pstate |
| /* If userspace is using ADI, it could potentially pass |
| * a pointer with version tag embedded in it. To maintain |
| * the ADI security, we must re-enable PSTATE.mcde before |
| * we continue execution in the kernel for another thread. |
| */ |
| .section .sun_m7_1insn_patch, "ax" |
| .word 661b |
| wrpr %g0, RTRAP_PSTATE|PSTATE_MCDE, %pstate |
| .previous |
| ba,pt %xcc, __handle_preemption_continue |
| wrpr %g0, RTRAP_PSTATE_IRQOFF, %pstate |
| |
| __handle_user_windows: |
| call fault_in_user_windows |
| 661: wrpr %g0, RTRAP_PSTATE, %pstate |
| /* If userspace is using ADI, it could potentially pass |
| * a pointer with version tag embedded in it. To maintain |
| * the ADI security, we must re-enable PSTATE.mcde before |
| * we continue execution in the kernel for another thread. |
| */ |
| .section .sun_m7_1insn_patch, "ax" |
| .word 661b |
| wrpr %g0, RTRAP_PSTATE|PSTATE_MCDE, %pstate |
| .previous |
| ba,pt %xcc, __handle_preemption_continue |
| wrpr %g0, RTRAP_PSTATE_IRQOFF, %pstate |
| |
| __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: |
| mov %l5, %o1 |
| add %sp, PTREGS_OFF, %o0 |
| mov %l0, %o2 |
| call do_notify_resume |
| 661: wrpr %g0, RTRAP_PSTATE, %pstate |
| /* If userspace is using ADI, it could potentially pass |
| * a pointer with version tag embedded in it. To maintain |
| * the ADI security, we must re-enable PSTATE.mcde before |
| * we continue execution in the kernel for another thread. |
| */ |
| .section .sun_m7_1insn_patch, "ax" |
| .word 661b |
| wrpr %g0, RTRAP_PSTATE|PSTATE_MCDE, %pstate |
| .previous |
| wrpr %g0, RTRAP_PSTATE_IRQOFF, %pstate |
| |
| /* 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_preemption_continue |
| srl %l4, 20, %l4 |
| |
| /* When returning from a NMI (%pil==15) interrupt we want to |
| * avoid running softirqs, doing IRQ tracing, preempting, etc. |
| */ |
| .globl rtrap_nmi |
| rtrap_nmi: ldx [%sp + PTREGS_OFF + PT_V9_TSTATE], %l1 |
| sethi %hi(0xf << 20), %l4 |
| and %l1, %l4, %l4 |
| andn %l1, %l4, %l1 |
| srl %l4, 20, %l4 |
| ba,pt %xcc, rtrap_no_irq_enable |
| nop |
| /* Do not actually set the %pil here. We will do that |
| * below after we clear PSTATE_IE in the %pstate register. |
| * If we re-enable interrupts here, we can recurse down |
| * the hardirq stack potentially endlessly, causing a |
| * stack overflow. |
| */ |
| |
| .align 64 |
| .globl rtrap_irq, rtrap, irqsz_patchme, rtrap_xcall |
| rtrap_irq: |
| rtrap: |
| /* mm/ultra.S:xcall_report_regs KNOWS about this load. */ |
| ldx [%sp + PTREGS_OFF + PT_V9_TSTATE], %l1 |
| rtrap_xcall: |
| sethi %hi(0xf << 20), %l4 |
| and %l1, %l4, %l4 |
| andn %l1, %l4, %l1 |
| srl %l4, 20, %l4 |
| #ifdef CONFIG_TRACE_IRQFLAGS |
| brnz,pn %l4, rtrap_no_irq_enable |
| nop |
| call trace_hardirqs_on |
| nop |
| /* Do not actually set the %pil here. We will do that |
| * below after we clear PSTATE_IE in the %pstate register. |
| * If we re-enable interrupts here, we can recurse down |
| * the hardirq stack potentially endlessly, causing a |
| * stack overflow. |
| * |
| * It is tempting to put this test and trace_hardirqs_on |
| * call at the 'rt_continue' label, but that will not work |
| * as that path hits unconditionally and we do not want to |
| * execute this in NMI return paths, for example. |
| */ |
| #endif |
| rtrap_no_irq_enable: |
| andcc %l1, TSTATE_PRIV, %l3 |
| bne,pn %icc, to_kernel |
| nop |
| |
| /* 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. Note |
| * that we are disabling interrupts via PSTATE_IE, not using |
| * %pil. |
| * |
| * 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 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_DO_NOTIFY_RESUME_MASK, %g0 |
| bne,pn %xcc, __handle_signal |
| ldub [%g6 + TI_WSAVED], %o2 |
| brnz,pn %o2, __handle_user_windows |
| nop |
| sethi %hi(TSTATE_PEF), %o0 |
| 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 |
| brz,pt %l3, 1f |
| mov %g6, %l2 |
| |
| /* Must do this before thread reg is clobbered below. */ |
| LOAD_PER_CPU_BASE(%g5, %g6, %i0, %i1, %i2) |
| 1: |
| ldx [%sp + PTREGS_OFF + PT_V9_G6], %g6 |
| ldx [%sp + PTREGS_OFF + PT_V9_G7], %g7 |
| |
| /* Normal globals are restored, go to trap globals. */ |
| 661: wrpr %g0, RTRAP_PSTATE_AG_IRQOFF, %pstate |
| nop |
| .section .sun4v_2insn_patch, "ax" |
| .word 661b |
| wrpr %g0, RTRAP_PSTATE_IRQOFF, %pstate |
| SET_GL(1) |
| .previous |
| |
| mov %l2, %g6 |
| |
| 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 |
| wrpr %l4, 0x0, %pil |
| wrpr %g0, 0x1, %tl |
| andn %l1, TSTATE_SYSCALL, %l1 |
| wrpr %l1, %g0, %tstate |
| wrpr %l2, %g0, %tpc |
| wrpr %o2, %g0, %tnpc |
| |
| brnz,pn %l3, kern_rtt |
| mov PRIMARY_CONTEXT, %l7 |
| |
| 661: ldxa [%l7 + %l7] ASI_DMMU, %l0 |
| .section .sun4v_1insn_patch, "ax" |
| .word 661b |
| ldxa [%l7 + %l7] ASI_MMU, %l0 |
| .previous |
| |
| sethi %hi(sparc64_kern_pri_nuc_bits), %l1 |
| ldx [%l1 + %lo(sparc64_kern_pri_nuc_bits)], %l1 |
| or %l0, %l1, %l0 |
| |
| 661: stxa %l0, [%l7] ASI_DMMU |
| .section .sun4v_1insn_patch, "ax" |
| .word 661b |
| stxa %l0, [%l7] ASI_MMU |
| .previous |
| |
| sethi %hi(KERNBASE), %l7 |
| flush %l7 |
| rdpr %wstate, %l1 |
| rdpr %otherwin, %l2 |
| srl %l1, 3, %l1 |
| |
| 661: wrpr %l2, %g0, %canrestore |
| .section .fast_win_ctrl_1insn_patch, "ax" |
| .word 661b |
| .word 0x89880000 ! normalw |
| .previous |
| |
| wrpr %l1, %g0, %wstate |
| brnz,pt %l2, user_rtt_restore |
| 661: wrpr %g0, %g0, %otherwin |
| .section .fast_win_ctrl_1insn_patch, "ax" |
| .word 661b |
| nop |
| .previous |
| |
| ldx [%g6 + TI_FLAGS], %g3 |
| wr %g0, ASI_AIUP, %asi |
| rdpr %cwp, %g1 |
| andcc %g3, _TIF_32BIT, %g0 |
| sub %g1, 1, %g1 |
| bne,pt %xcc, user_rtt_fill_32bit |
| wrpr %g1, %cwp |
| ba,a,pt %xcc, user_rtt_fill_64bit |
| nop |
| |
| user_rtt_fill_fixup_dax: |
| ba,pt %xcc, user_rtt_fill_fixup_common |
| mov 1, %g3 |
| |
| user_rtt_fill_fixup_mna: |
| ba,pt %xcc, user_rtt_fill_fixup_common |
| mov 2, %g3 |
| |
| user_rtt_fill_fixup: |
| ba,pt %xcc, user_rtt_fill_fixup_common |
| clr %g3 |
| |
| user_rtt_pre_restore: |
| add %g1, 1, %g1 |
| wrpr %g1, 0x0, %cwp |
| |
| user_rtt_restore: |
| restore |
| rdpr %canrestore, %g1 |
| wrpr %g1, 0x0, %cleanwin |
| retry |
| nop |
| |
| kern_rtt: rdpr %canrestore, %g1 |
| brz,pn %g1, kern_rtt_fill |
| nop |
| kern_rtt_restore: |
| stw %g0, [%sp + PTREGS_OFF + PT_V9_MAGIC] |
| 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 |
| nop |
| cmp %l4, 0 |
| bne,pn %xcc, kern_fpucheck |
| nop |
| call preempt_schedule_irq |
| nop |
| ba,pt %xcc, rtrap |
| #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] |
