From 119e9db233ad0f4cbd4cfb9f9385a7bca378b37d Mon Sep 17 00:00:00 2001 From: Zeng Chi Date: Mon, 21 Sep 2026 18:24:42 +0800 Subject: KVM: Don't pre-reserve xarray entries when storing empty/NULL attributes Skip the xarray reservation loop when clearing all memory attributes, as storing NULL only erases the entry and never needs to allocate, so no reservation (and no cleanup of a failed one) is required in that case. Suggested-by: Sean Christopherson Cc: David Ballesteros Signed-off-by: Zeng Chi Link: https://patch.msgid.link/20260921102442.1232375-1-zeng_chi911@163.com [sean: split to separate patch] Signed-off-by: Sean Christopherson --- arch/m68k/coldfire/entry.S | 198 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 198 insertions(+) create mode 100644 arch/m68k/coldfire/entry.S (limited to 'arch/m68k/coldfire/entry.S') diff --git a/arch/m68k/coldfire/entry.S b/arch/m68k/coldfire/entry.S new file mode 100644 index 000000000..4ea08336e --- /dev/null +++ b/arch/m68k/coldfire/entry.S @@ -0,0 +1,198 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later + * + * entry.S -- interrupt and exception processing for ColdFire + * + * Copyright (C) 1999-2007, Greg Ungerer (gerg@snapgear.com) + * Copyright (C) 1998 D. Jeff Dionne , + * Kenneth Albanowski , + * Copyright (C) 2000 Lineo Inc. (www.lineo.com) + * Copyright (C) 2004-2006 Macq Electronique SA. (www.macqel.com) + * + * Based on: + * + * linux/arch/m68k/kernel/entry.S + * + * Copyright (C) 1991, 1992 Linus Torvalds + * + * Linux/m68k support by Hamish Macdonald + * + * 68060 fixes by Jesper Skov + * ColdFire support by Greg Ungerer (gerg@snapgear.com) + * 5307 fixes by David W. Miller + * linux 2.4 support David McCullough + * Bug, speed and maintainability fixes by Philippe De Muyter + */ + +#include +#include +#include +#include +#include +#include +#include + +#ifdef CONFIG_COLDFIRE_SW_A7 +/* + * Define software copies of the supervisor and user stack pointers. + */ +.bss +sw_ksp: +.long 0 +sw_usp: +.long 0 +#endif /* CONFIG_COLDFIRE_SW_A7 */ + +.text + +.globl system_call +.globl resume +.globl ret_from_exception +.globl sys_call_table +.globl inthandler + +enosys: + mov.l #sys_ni_syscall,%d3 + bra 1f + +ENTRY(system_call) + SAVE_ALL_SYS + move #0x2000,%sr /* enable intrs again */ + GET_CURRENT(%d2) + + cmpl #NR_syscalls,%d0 + jcc enosys + lea sys_call_table,%a0 + lsll #2,%d0 /* movel %a0@(%d0:l:4),%d3 */ + movel %a0@(%d0),%d3 + jeq enosys + +1: + movel %sp,%d2 /* get thread_info pointer */ + andl #-THREAD_SIZE,%d2 /* at start of kernel stack */ + movel %d2,%a0 + movel %a0@,%a1 /* save top of frame */ + movel %sp,%a1@(TASK_THREAD+THREAD_ESP0) + btst #(TIF_SYSCALL_TRACE%8),%a0@(TINFO_FLAGS+(31-TIF_SYSCALL_TRACE)/8) + bnes 1f + + movel %d3,%a0 + jbsr %a0@ + movel %d0,%sp@(PT_OFF_D0) /* save the return value */ + jra ret_from_exception +1: + movel #-ENOSYS,%d2 /* strace needs -ENOSYS in PT_OFF_D0 */ + movel %d2,PT_OFF_D0(%sp) /* on syscall entry */ + subql #4,%sp + SAVE_SWITCH_STACK + jbsr syscall_trace_enter + RESTORE_SWITCH_STACK + addql #4,%sp + addql #1,%d0 + jeq ret_from_exception + movel %d3,%a0 + jbsr %a0@ + movel %d0,%sp@(PT_OFF_D0) /* save the return value */ + subql #4,%sp /* dummy return address */ + SAVE_SWITCH_STACK + jbsr syscall_trace_leave + RESTORE_SWITCH_STACK + addql #4,%sp + +ret_from_exception: + move #0x2700,%sr /* disable intrs */ + btst #5,%sp@(PT_OFF_SR) /* check if returning to kernel */ + jeq Luser_return /* if so, skip resched, signals */ + +#ifdef CONFIG_PREEMPTION + movel %sp,%d1 /* get thread_info pointer */ + andl #-THREAD_SIZE,%d1 /* at base of kernel stack */ + movel %d1,%a0 + movel %a0@(TINFO_FLAGS),%d1 /* get thread_info->flags */ + andl #(1<flags (low 8 bits) */ + jne Lwork_to_do /* still work to do */ + +Lreturn: + RESTORE_USER + +Lwork_to_do: + movel %a0@(TINFO_FLAGS),%d1 /* get thread_info->flags */ + move #0x2000,%sr /* enable intrs again */ + btst #TIF_NEED_RESCHED,%d1 + jne reschedule + +Lsignal_return: + subql #4,%sp /* dummy return address */ + SAVE_SWITCH_STACK + pea %sp@(SWITCH_STACK_SIZE) + jsr do_notify_resume + addql #4,%sp + RESTORE_SWITCH_STACK + addql #4,%sp + jmp Luser_return + +/* + * This is the generic interrupt handler (for all hardware interrupt + * sources). Calls up to high level code to do all the work. + */ +ENTRY(inthandler) + SAVE_ALL_INT + GET_CURRENT(%d2) + + movew %sp@(PT_OFF_FORMATVEC),%d0 /* put exception # in d0 */ + andl #0x03fc,%d0 /* mask out vector only */ + + movel %sp,%sp@- /* push regs arg */ + lsrl #2,%d0 /* calculate real vector # */ + movel %d0,%sp@- /* push vector number */ + jbsr do_IRQ /* call high level irq handler */ + lea %sp@(8),%sp /* pop args off stack */ + + bra ret_from_exception + +/* + * Beware - when entering resume, prev (the current task) is + * in a0, next (the new task) is in a1, so don't change these + * registers until their contents are no longer needed. + */ +ENTRY(resume) + movew %sr,%d1 /* save current status */ + movew %d1,%a0@(TASK_THREAD+THREAD_SR) + movel %a0,%d1 /* get prev thread in d1 */ + SAVE_SWITCH_STACK + movel %sp,%a0@(TASK_THREAD+THREAD_KSP) /* save kernel stack pointer */ + RDUSP /* movel %usp,%a3 */ + movel %a3,%a0@(TASK_THREAD+THREAD_USP) /* save thread user stack */ +#ifdef CONFIG_MMU + movel %a1,%a2 /* set new current */ +#endif + movel %a1@(TASK_THREAD+THREAD_USP),%a3 /* restore thread user stack */ + WRUSP /* movel %a3,%usp */ + movel %a1@(TASK_THREAD+THREAD_KSP),%sp /* restore new kernel stack */ + movew %a1@(TASK_THREAD+THREAD_SR),%d7 /* restore new status */ + movew %d7,%sr + RESTORE_SWITCH_STACK + rts + -- cgit v1.3.1