Merge git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6

* git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6:
  sh: LCDC dcache flush for deferred io
  sh: Fix compiler error and include the definition of IS_ERR_VALUE
  sh: re-add LCDC fbdev support to the Migo-R defconfig
  sh: fix se7724 ceu names
  sh: ms7724se: Enable sh_eth in defconfig.
  arch/sh/boards/mach-se/7206/io.c: Remove unnecessary semicolons
  sh: ms7724se: Add sh_eth support
  nommu: provide follow_pfn().
  sh: Kill off unused DEBUG_BOOTMEM symbol.
  perf_counter tools: add cpu_relax()/rmb() definitions for sh.
  sh64: Hook up page fault events for software perf counters.
  sh: Hook up page fault events for software perf counters.
  sh: make set_perf_counter_pending() static inline.
  clocksource: sh_tmu: Make undefined TCOR behaviour less undefined.

1 files changed, 21 insertions, 0 deletions

diff --git a/mm/nommu.c b/mm/nommu.c
index bf0cc762a7d2..53cab10fece4 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -238,6 +238,27 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
 }
 EXPORT_SYMBOL(get_user_pages);
 
+/**
+ * follow_pfn - look up PFN at a user virtual address
+ * @vma: memory mapping
+ * @address: user virtual address
+ * @pfn: location to store found PFN
+ *
+ * Only IO mappings and raw PFN mappings are allowed.
+ *
+ * Returns zero and the pfn at @pfn on success, -ve otherwise.
+ */
+int follow_pfn(struct vm_area_struct *vma, unsigned long address,
+        unsigned long *pfn)
+{
+        if (!(vma->vm_flags & (VM_IO | VM_PFNMAP)))
+                return -EINVAL;
+
+        *pfn = address >> PAGE_SHIFT;
+        return 0;
+}
+EXPORT_SYMBOL(follow_pfn);
+
 DEFINE_RWLOCK(vmlist_lock);
 struct vm_struct *vmlist;