1/****************************************************************************** 2 * grant_table.c 3 * x86 specific part 4 * 5 * Granting foreign access to our memory reservation. 6 * 7 * Copyright (c) 2005-2006, Christopher Clark 8 * Copyright (c) 2004-2005, K A Fraser 9 * Copyright (c) 2008 Isaku Yamahata <yamahata at valinux co jp> 10 * VA Linux Systems Japan. Split out x86 specific part. 11 * 12 * This program is free software; you can redistribute it and/or 13 * modify it under the terms of the GNU General Public License version 2 14 * as published by the Free Software Foundation; or, when distributed 15 * separately from the Linux kernel or incorporated into other 16 * software packages, subject to the following license: 17 * 18 * Permission is hereby granted, free of charge, to any person obtaining a copy 19 * of this source file (the "Software"), to deal in the Software without 20 * restriction, including without limitation the rights to use, copy, modify, 21 * merge, publish, distribute, sublicense, and/or sell copies of the Software, 22 * and to permit persons to whom the Software is furnished to do so, subject to 23 * the following conditions: 24 * 25 * The above copyright notice and this permission notice shall be included in 26 * all copies or substantial portions of the Software. 27 * 28 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 29 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 30 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 31 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 32 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 33 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS 34 * IN THE SOFTWARE. 35 */ 36 37#include <linux/sched.h> 38#include <linux/mm.h> 39#include <linux/vmalloc.h> 40 41#include <xen/interface/xen.h> 42#include <xen/page.h> 43#include <xen/grant_table.h> 44 45#include <asm/pgtable.h> 46 47static int map_pte_fn(pte_t *pte, struct page *pmd_page, 48 unsigned long addr, void *data) 49{ 50 unsigned long **frames = (unsigned long **)data; 51 52 set_pte_at(&init_mm, addr, pte, mfn_pte((*frames)[0], PAGE_KERNEL)); 53 (*frames)++; 54 return 0; 55} 56 57static int unmap_pte_fn(pte_t *pte, struct page *pmd_page, 58 unsigned long addr, void *data) 59{ 60 61 set_pte_at(&init_mm, addr, pte, __pte(0)); 62 return 0; 63} 64 65int arch_gnttab_map_shared(unsigned long *frames, unsigned long nr_gframes, 66 unsigned long max_nr_gframes, 67 struct grant_entry **__shared) 68{ 69 int rc; 70 struct grant_entry *shared = *__shared; 71 72 if (shared == NULL) { 73 struct vm_struct *area = 74 xen_alloc_vm_area(PAGE_SIZE * max_nr_gframes); 75 BUG_ON(area == NULL); 76 shared = area->addr; 77 *__shared = shared; 78 } 79 80 rc = apply_to_page_range(&init_mm, (unsigned long)shared, 81 PAGE_SIZE * nr_gframes, 82 map_pte_fn, &frames); 83 return rc; 84} 85 86void arch_gnttab_unmap_shared(struct grant_entry *shared, 87 unsigned long nr_gframes) 88{ 89 apply_to_page_range(&init_mm, (unsigned long)shared, 90 PAGE_SIZE * nr_gframes, unmap_pte_fn, NULL); 91} 92