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When mapping a foreign page with xenbus_map_ring_valloc() with the GNTTABOP_map_grant_ref hypercall, set the GNTMAP_contains_pte flag and pass a pointer to the PTE (in init_mm). After the page is mapped, the usual fault mechanism can be used to update additional MMs. This allows the vmalloc_sync_all() to be removed from alloc_vm_area(). Signed-off-by: David Vrabel <david.vrabel@citrix.com> Acked-by: Andrew Morton <akpm@linux-foundation.org> [v1: Squashed fix by Michal for no-mmu case] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Michal Simek <monstr@monstr.eu>
92 lines
3.0 KiB
C
92 lines
3.0 KiB
C
/******************************************************************************
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* grant_table.c
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* x86 specific part
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*
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* Granting foreign access to our memory reservation.
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*
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* Copyright (c) 2005-2006, Christopher Clark
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* Copyright (c) 2004-2005, K A Fraser
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* Copyright (c) 2008 Isaku Yamahata <yamahata at valinux co jp>
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* VA Linux Systems Japan. Split out x86 specific part.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License version 2
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* as published by the Free Software Foundation; or, when distributed
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* separately from the Linux kernel or incorporated into other
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* software packages, subject to the following license:
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this source file (the "Software"), to deal in the Software without
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* restriction, including without limitation the rights to use, copy, modify,
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* merge, publish, distribute, sublicense, and/or sell copies of the Software,
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* and to permit persons to whom the Software is furnished to do so, subject to
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* the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
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* IN THE SOFTWARE.
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*/
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#include <linux/sched.h>
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#include <linux/mm.h>
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#include <linux/vmalloc.h>
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#include <xen/interface/xen.h>
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#include <xen/page.h>
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#include <xen/grant_table.h>
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#include <asm/pgtable.h>
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static int map_pte_fn(pte_t *pte, struct page *pmd_page,
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unsigned long addr, void *data)
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{
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unsigned long **frames = (unsigned long **)data;
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set_pte_at(&init_mm, addr, pte, mfn_pte((*frames)[0], PAGE_KERNEL));
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(*frames)++;
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return 0;
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}
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static int unmap_pte_fn(pte_t *pte, struct page *pmd_page,
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unsigned long addr, void *data)
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{
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set_pte_at(&init_mm, addr, pte, __pte(0));
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return 0;
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}
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int arch_gnttab_map_shared(unsigned long *frames, unsigned long nr_gframes,
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unsigned long max_nr_gframes,
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struct grant_entry **__shared)
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{
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int rc;
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struct grant_entry *shared = *__shared;
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if (shared == NULL) {
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struct vm_struct *area =
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alloc_vm_area(PAGE_SIZE * max_nr_gframes, NULL);
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BUG_ON(area == NULL);
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shared = area->addr;
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*__shared = shared;
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}
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rc = apply_to_page_range(&init_mm, (unsigned long)shared,
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PAGE_SIZE * nr_gframes,
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map_pte_fn, &frames);
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return rc;
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}
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void arch_gnttab_unmap_shared(struct grant_entry *shared,
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unsigned long nr_gframes)
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{
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apply_to_page_range(&init_mm, (unsigned long)shared,
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PAGE_SIZE * nr_gframes, unmap_pte_fn, NULL);
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}
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