mmu.c

 1// SPDX-License-Identifier: GPL-2.0
 2
 3#include <linux/pfn.h>
 4#include <asm/xen/page.h>
 5#include <asm/xen/hypercall.h>
 6#include <xen/interface/memory.h>
 7
 8#include "xen-ops.h"
 9
10unsigned long arbitrary_virt_to_mfn(void *vaddr)
11{
12	xmaddr_t maddr = arbitrary_virt_to_machine(vaddr);
13
14	return PFN_DOWN(maddr.maddr);
15}
16
17xmaddr_t arbitrary_virt_to_machine(void *vaddr)
18{
19	unsigned long address = (unsigned long)vaddr;
20	unsigned int level;
21	pte_t *pte;
22	unsigned offset;
23
24	/*
25	 * if the PFN is in the linear mapped vaddr range, we can just use
26	 * the (quick) virt_to_machine() p2m lookup
27	 */
28	if (virt_addr_valid(vaddr))
29		return virt_to_machine(vaddr);
30
31	/* otherwise we have to do a (slower) full page-table walk */
32
33	pte = lookup_address(address, &level);
34	BUG_ON(pte == NULL);
35	offset = address & ~PAGE_MASK;
36	return XMADDR(((phys_addr_t)pte_mfn(*pte) << PAGE_SHIFT) + offset);
37}
38EXPORT_SYMBOL_GPL(arbitrary_virt_to_machine);
39
40/* Returns: 0 success */
41int xen_unmap_domain_gfn_range(struct vm_area_struct *vma,
42			       int nr, struct page **pages)
43{
44	if (!xen_pv_domain())
45		return xen_xlate_unmap_gfn_range(vma, nr, pages);
46
47	if (!pages)
48		return 0;
49
50	return -EINVAL;
51}
52EXPORT_SYMBOL_GPL(xen_unmap_domain_gfn_range);