/* $NetBSD: idt.c,v 1.11 2019/06/17 06:38:30 msaitoh Exp $ */ /*- * Copyright (c) 1996, 1997, 1998, 2000, 2009 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Charles M. Hannum, by Jason R. Thorpe of the Numerical Aerospace * Simulation Facility NASA Ames Research Center, and by Andrew Doran. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ /*- * Copyright (c) 1982, 1987, 1990 The Regents of the University of California. * All rights reserved. * * This code is derived from software contributed to Berkeley by * William Jolitz. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)machdep.c 7.4 (Berkeley) 6/3/91 */ #include __KERNEL_RCSID(0, "$NetBSD: idt.c,v 1.11 2019/06/17 06:38:30 msaitoh Exp $"); #include #include #include #include #include #include #include /* * XEN PV and native have a different idea of what idt entries should * look like. */ idt_descriptor_t *idt; static char idt_allocmap[NIDT]; /* Normalise across XEN PV and native */ #if defined(XENPV) void set_idtgate(struct trap_info *xen_idd, void *function, int ist, int type, int dpl, int sel) { /* * Find the page boundary in which the descriptor resides. * We make an assumption here, that the descriptor is part of * a table (array), which fits in a page and is page aligned. * * This assumption is from the usecases at early startup in * machine/machdep.c * * Thus this function may not work in the "general" case of a * randomly located idt entry template (for eg:). */ vaddr_t xen_idt_vaddr = ((vaddr_t) xen_idd) & ~PAGE_MASK; //kpreempt_disable(); #if defined(__x86_64__) /* Make it writeable, so we can update the values. */ pmap_changeprot_local(xen_idt_vaddr, VM_PROT_READ | VM_PROT_WRITE); #endif /* __x86_64 */ xen_idd->cs = sel; xen_idd->address = (unsigned long) function; xen_idd->flags = dpl; /* * Again we make the assumption that the descriptor is * implicitly part of an idt, which we infer as * xen_idt_vaddr. (See above). */ xen_idd->vector = xen_idd - (struct trap_info *)xen_idt_vaddr; /* Back to read-only, as it should be. */ #if defined(__x86_64__) pmap_changeprot_local(xen_idt_vaddr, VM_PROT_READ); #endif /* __x86_64 */ //kpreempt_enable(); } void unset_idtgate(struct trap_info *xen_idd) { #if defined(__x86_64__) vaddr_t xen_idt_vaddr = ((vaddr_t) xen_idd) & PAGE_MASK; /* Make it writeable, so we can update the values. */ pmap_changeprot_local(xen_idt_vaddr, VM_PROT_READ | VM_PROT_WRITE); #endif /* __x86_64 */ /* Zero it */ memset(xen_idd, 0, sizeof (*xen_idd)); #if defined(__x86_64__) /* Back to read-only, as it should be. */ pmap_changeprot_local(xen_idt_vaddr, VM_PROT_READ); #endif /* __x86_64 */ } #else /* XENPV */ void set_idtgate(struct gate_descriptor *idd, void *function, int ist, int type, int dpl, int sel) { setgate(idd, function, ist, type, dpl, sel); } void unset_idtgate(struct gate_descriptor *idd) { unsetgate(idd); } #endif /* XENPV */ /* * Allocate an IDT vector slot within the given range. * cpu_lock will be held unless single threaded during early boot. */ int idt_vec_alloc(int low, int high) { int vec; KASSERT(mutex_owned(&cpu_lock) || !mp_online); for (vec = low; vec <= high; vec++) { if (idt_allocmap[vec] == 0) { /* idt_vec_free() can be unlocked, so membar. */ membar_sync(); idt_allocmap[vec] = 1; return vec; } } return 0; } void idt_vec_reserve(int vec) { int result; KASSERT(mutex_owned(&cpu_lock) || !mp_online); result = idt_vec_alloc(vec, vec); if (result != vec) { panic("%s: failed to reserve vec %d", __func__, vec); } } void idt_vec_set(int vec, void (*function)(void)) { KASSERT(idt_allocmap[vec] == 1); set_idtgate(&idt[vec], function, 0, SDT_SYS386IGT, SEL_KPL, GSEL(GCODE_SEL, SEL_KPL)); } /* * Free IDT vector. No locking required as release is atomic. */ void idt_vec_free(int vec) { unset_idtgate(&idt[vec]); idt_allocmap[vec] = 0; }