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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			xen_alloc_vm_area(PAGE_SIZE * max_nr_gframes);
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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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