/* * Copyright (c) 2006 Jakub Jermar * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * - Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * - 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. * - The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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. */ /** @addtogroup kernel_ia32_ddi * @{ */ /** @file */ #include <ddi/ddi.h> #include <arch/ddi/ddi.h> #include <assert.h> #include <proc/task.h> #include <stddef.h> #include <adt/bitmap.h> #include <mm/slab.h> #include <arch/pm.h> #include <errno.h> #include <arch/cpu.h> #include <cpu.h> #include <arch.h> #include <align.h> /** Install I/O Permission bitmap. * * Current task's I/O permission bitmap, if any, is installed * in the current CPU's TSS. * * Interrupts must be disabled prior this call. * */ void io_perm_bitmap_install(void) { /* First, copy the I/O Permission Bitmap. */ irq_spinlock_lock(&TASK->lock, false); size_t ver = TASK->arch.iomapver; size_t elements = TASK->arch.iomap.elements; if (elements > 0) { assert(TASK->arch.iomap.bits); bitmap_t iomap; bitmap_initialize(&iomap, TSS_IOMAP_SIZE * 8, CPU->arch.tss->iomap); bitmap_copy(&iomap, &TASK->arch.iomap, elements); /* * Set the trailing bits in the last byte of the map to disable * I/O access. */ bitmap_set_range(&iomap, elements, ALIGN_UP(elements, 8) - elements); /* * It is safe to set the trailing eight bits because of the * extra convenience byte in TSS_IOMAP_SIZE. */ bitmap_set_range(&iomap, ALIGN_UP(elements, 8), 8); } irq_spinlock_unlock(&TASK->lock, false); /* * Second, adjust TSS segment limit. * Take the extra ending byte with all bits set into account. */ ptr_16_32_t cpugdtr; gdtr_store(&cpugdtr); descriptor_t *gdt_p = (descriptor_t *) cpugdtr.base; size_t size = bitmap_size(elements); gdt_setlimit(&gdt_p[TSS_DES], TSS_BASIC_SIZE + size); gdtr_load(&cpugdtr); /* * Before we load new TSS limit, the current TSS descriptor * type must be changed to describe inactive TSS. */ gdt_p[TSS_DES].access = AR_PRESENT | AR_TSS | DPL_KERNEL; tr_load(GDT_SELECTOR(TSS_DES)); /* * Update the generation count so that faults caused by * early accesses can be serviced. */ CPU->arch.iomapver_copy = ver; } /** @} */