From 76cb841cb886eef6b3bee341a2266c76578724ad Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Mon, 6 May 2024 03:02:30 +0200 Subject: Adding upstream version 4.19.249. Signed-off-by: Daniel Baumann --- arch/sparc/kernel/rtrap_64.S | 378 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 378 insertions(+) create mode 100644 arch/sparc/kernel/rtrap_64.S (limited to 'arch/sparc/kernel/rtrap_64.S') diff --git a/arch/sparc/kernel/rtrap_64.S b/arch/sparc/kernel/rtrap_64.S new file mode 100644 index 000000000..29aa34f11 --- /dev/null +++ b/arch/sparc/kernel/rtrap_64.S @@ -0,0 +1,378 @@ +/* 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 +#include +#include +#include +#include +#include +#include + +#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: + add %sp, PTREGS_OFF, %o0 + 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] -- cgit v1.2.3