The patch titled
add vm_insert_pfn()
has been added to the -mm tree. Its filename is
add-vm_insert_pfn.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: add vm_insert_pfn()
From: Nick Piggin <npiggin@xxxxxxx>
Add a vm_insert_pfn helper, so that ->fault handlers can have nopfn
functionality by installing their own pte and returning NULL.
Signed-off-by: Nick Piggin <npiggin@xxxxxxx>
Signed-off-by: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Arnd Bergmann <arnd.bergmann@xxxxxxxxxx>
Cc: Hugh Dickins <hugh@xxxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/mm.h | 1
mm/memory.c | 44 +++++++++++++++++++++++++++++++++++++++++++
2 files changed, 45 insertions(+)
diff -puN include/linux/mm.h~add-vm_insert_pfn include/linux/mm.h
--- a/include/linux/mm.h~add-vm_insert_pfn
+++ a/include/linux/mm.h
@@ -1124,6 +1124,7 @@ unsigned long vmalloc_to_pfn(void *addr)
int remap_pfn_range(struct vm_area_struct *, unsigned long addr,
unsigned long pfn, unsigned long size, pgprot_t);
int vm_insert_page(struct vm_area_struct *, unsigned long addr, struct page *);
+int vm_insert_pfn(struct vm_area_struct *, unsigned long addr, unsigned long pfn);
struct page *follow_page(struct vm_area_struct *, unsigned long address,
unsigned int foll_flags);
diff -puN mm/memory.c~add-vm_insert_pfn mm/memory.c
--- a/mm/memory.c~add-vm_insert_pfn
+++ a/mm/memory.c
@@ -1277,6 +1277,50 @@ int vm_insert_page(struct vm_area_struct
}
EXPORT_SYMBOL(vm_insert_page);
+/**
+ * vm_insert_pfn - insert single pfn into user vma
+ * @vma: user vma to map to
+ * @addr: target user address of this page
+ * @pfn: source kernel pfn
+ *
+ * Similar to vm_inert_page, this allows drivers to insert individual pages
+ * they've allocated into a user vma. Same comments apply.
+ *
+ * This function should only be called from a vm_ops->fault handler, and
+ * in that case the handler should return NULL.
+ */
+int vm_insert_pfn(struct vm_area_struct *vma, unsigned long addr, unsigned long pfn)
+{
+ struct mm_struct *mm = vma->vm_mm;
+ int retval;
+ pte_t *pte, entry;
+ spinlock_t *ptl;
+
+ BUG_ON(!(vma->vm_flags & VM_PFNMAP));
+ BUG_ON(is_cow_mapping(vma->vm_flags));
+
+ retval = -ENOMEM;
+ pte = get_locked_pte(mm, addr, &ptl);
+ if (!pte)
+ goto out;
+ retval = -EBUSY;
+ if (!pte_none(*pte))
+ goto out_unlock;
+
+ /* Ok, finally just insert the thing.. */
+ entry = pfn_pte(pfn, vma->vm_page_prot);
+ set_pte_at(mm, addr, pte, entry);
+ update_mmu_cache(vma, addr, entry);
+
+ retval = 0;
+out_unlock:
+ pte_unmap_unlock(pte, ptl);
+
+out:
+ return retval;
+}
+EXPORT_SYMBOL(vm_insert_pfn);
+
/*
* maps a range of physical memory into the requested pages. the old
* mappings are removed. any references to nonexistent pages results
_
Patches currently in -mm which might be from npiggin@xxxxxxx are
git-block.patch
add-vm_insert_pfn.patch
mm-vm_insert_pfn.patch
mm-vm_insert_pfn-tidy.patch
buffer-memorder-fix.patch
fs-fix-__block_write_full_page-error-case-buffer-submission.patch
inotify-read-return-val-fix.patch
sched-avoid-div-in-rebalance_tick.patch
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