[PATCH 6/9] x86/xen: do not use _PAGE_IOMAP in xen_remap_domain_mfn_range()

From: David Vrabel
Date: Tue Apr 15 2014 - 10:18:26 EST


_PAGE_IOMAP is used in xen_remap_domain_mfn_range() to prevent the
pfn_pte() call in remap_area_mfn_pte_fn() from using the p2m to translate
the MFN. If mfn_pte() is used instead, the p2m look up is avoided and
the use of _PAGE_IOMAP is no longer needed.

Signed-off-by: David Vrabel <david.vrabel@xxxxxxxxxx>
---
arch/x86/xen/mmu.c | 4 +---
1 files changed, 1 insertions(+), 3 deletions(-)

diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index 86e02ea..d916024 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -2522,7 +2522,7 @@ static int remap_area_mfn_pte_fn(pte_t *ptep, pgtable_t token,
unsigned long addr, void *data)
{
struct remap_data *rmd = data;
- pte_t pte = pte_mkspecial(pfn_pte(rmd->mfn++, rmd->prot));
+ pte_t pte = pte_mkspecial(mfn_pte(rmd->mfn++, rmd->prot));

rmd->mmu_update->ptr = virt_to_machine(ptep).maddr;
rmd->mmu_update->val = pte_val_ma(pte);
@@ -2547,8 +2547,6 @@ int xen_remap_domain_mfn_range(struct vm_area_struct *vma,
if (xen_feature(XENFEAT_auto_translated_physmap))
return -EINVAL;

- prot = __pgprot(pgprot_val(prot) | _PAGE_IOMAP);
-
BUG_ON(!((vma->vm_flags & (VM_PFNMAP | VM_IO)) == (VM_PFNMAP | VM_IO)));

rmd.mfn = mfn;
--
1.7.2.5

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/