/* * Copyright (c) 2016 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_amd64 * @{ */ /** @file */ #include <arch/vreg.h> #include <arch/pm.h> #include <config.h> #include <typedefs.h> #include <arch/asm.h> #include <panic.h> #include <mm/km.h> #include <mm/frame.h> /* * During initialization, we need to make sure that context_save() and * context_restore() touch some meaningful address when saving/restoring VREGs. * When a processor is initialized, we set its FS base to a private page and * vreg_ptr to zero. */ static uint64_t vreg_tp_dummy; uint64_t *vreg_ptr = &vreg_tp_dummy; /** * Allocate and initialize a per-CPU user page to be accessible via the FS * segment register and to hold the virtual registers. */ void vreg_init(void) { uintptr_t frame; uint64_t *page; frame = frame_alloc(1, FRAME_ATOMIC | FRAME_HIGHMEM, 0); if (!frame) panic("Cannot allocate VREG frame."); page = (uint64_t *) km_map(frame, PAGE_SIZE, PAGE_SIZE, PAGE_READ | PAGE_WRITE | PAGE_USER | PAGE_CACHEABLE); write_msr(AMD_MSR_FS, (uintptr_t) page); vreg_ptr = NULL; } /** @} */