From: Matthew Wilcox <willy@xxxxxxxxxxxxxxx>
Similar to vm_insert_pfn(), but for PMDs rather than PTEs. Should this
be in m/huge_memory.c?
Signed-off-by: Matthew Wilcox <willy@xxxxxxxxxxxxxxx>
---
include/linux/mm.h | 2 ++
mm/memory.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 50 insertions(+)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 0a47817..d0de9fa 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1960,6 +1960,8 @@ int vm_insert_pfn(struct vm_area_struct *vma, unsigned long addr,
unsigned long pfn);
int vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
unsigned long pfn);
+int vm_insert_pfn_pmd(struct vm_area_struct *, unsigned long addr, pmd_t *,
+ unsigned long pfn);
int vm_iomap_memory(struct vm_area_struct *vma, phys_addr_t start, unsigned long len);
diff --git a/mm/memory.c b/mm/memory.c
index 3368785..993be2b 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1648,6 +1648,54 @@ int vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
}
EXPORT_SYMBOL(vm_insert_mixed);
+static int insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr,
+ pmd_t *pmd, unsigned long pfn, pgprot_t prot)
+{
+ struct mm_struct *mm = vma->vm_mm;
+ int retval;
+ pmd_t entry;
+ spinlock_t *ptl;
+
+ ptl = pmd_lock(mm, pmd);
+ retval = -EBUSY;
+ if (!pmd_none(*pmd))
+ goto out_unlock;
+
+ /* Ok, finally just insert the thing.. */
+ entry = pmd_mkspecial(pmd_mkhuge(pfn_pmd(pfn, prot)));
+ set_pmd_at(mm, addr, pmd, entry);
+ update_mmu_cache_pmd(vma, addr, pmd);
+
+ retval = 0;
+ out_unlock:
+ spin_unlock(ptl);
+ return retval;
+}
+
+int vm_insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr,
+ pmd_t *pmd, unsigned long pfn)
+{
+ pgprot_t pgprot = vma->vm_page_prot;
+ /*
+ * Technically, architectures with pte_special can avoid all these
+ * restrictions (same for remap_pfn_range). However we would like
+ * consistency in testing and feature parity among all, so we should
+ * try to keep these invariants in place for everybody.
+ */
+ BUG_ON(!(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)));
+ BUG_ON((vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)) ==
+ (VM_PFNMAP|VM_MIXEDMAP));
+ BUG_ON((vma->vm_flags & VM_PFNMAP) && is_cow_mapping(vma->vm_flags));
+ BUG_ON((vma->vm_flags & VM_MIXEDMAP) && pfn_valid(pfn));
+
+ if (addr < vma->vm_start || addr >= vma->vm_end)
+ return -EFAULT;
+ if (track_pfn_insert(vma, &pgprot, pfn))
+ return -EINVAL;
+ return insert_pfn_pmd(vma, addr, pmd, pfn, pgprot);
+}
+EXPORT_SYMBOL(vm_insert_pfn_pmd);
+
/*
* maps a range of physical memory into the requested pages. the old
* mappings are removed. any references to nonexistent pages results
--
2.1.0
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