x86/xen/mmu.c

0001 // SPDX-License-Identifier: GPL-2.0
0002
0003 #include <linux/pfn.h>
0004 #include <asm/xen/page.h>
0005 #include <asm/xen/hypercall.h>
0006 #include <xen/interface/memory.h>
0007
0008 #include "multicalls.h"
0009 #include "mmu.h"
0010
0011 unsigned long arbitrary_virt_to_mfn(void *vaddr)
0012 {
0013     xmaddr_t maddr = arbitrary_virt_to_machine(vaddr);
0014
0015     return PFN_DOWN(maddr.maddr);
0016 }
0017
0018 xmaddr_t arbitrary_virt_to_machine(void *vaddr)
0019 {
0020     unsigned long address = (unsigned long)vaddr;
0021     unsigned int level;
0022     pte_t *pte;
0023     unsigned offset;
0024
0025     /*
0026      * if the PFN is in the linear mapped vaddr range, we can just use
0027      * the (quick) virt_to_machine() p2m lookup
0028      */
0029     if (virt_addr_valid(vaddr))
0030         return virt_to_machine(vaddr);
0031
0032     /* otherwise we have to do a (slower) full page-table walk */
0033
0034     pte = lookup_address(address, &level);
0035     BUG_ON(pte == NULL);
0036     offset = address & ~PAGE_MASK;
0037     return XMADDR(((phys_addr_t)pte_mfn(*pte) << PAGE_SHIFT) + offset);
0038 }
0039 EXPORT_SYMBOL_GPL(arbitrary_virt_to_machine);
0040
0041 /* Returns: 0 success */
0042 int xen_unmap_domain_gfn_range(struct vm_area_struct *vma,
0043                    int nr, struct page **pages)
0044 {
0045     if (xen_feature(XENFEAT_auto_translated_physmap))
0046         return xen_xlate_unmap_gfn_range(vma, nr, pages);
0047
0048     if (!pages)
0049         return 0;
0050
0051     return -EINVAL;
0052 }
0053 EXPORT_SYMBOL_GPL(xen_unmap_domain_gfn_range);