[PATCH] kdump: Routines for copying dump pages
[linux-3.10.git] / arch / i386 / mm / highmem.c
index 4b7aaf9..b6eb4dc 100644 (file)
@@ -75,6 +75,24 @@ void kunmap_atomic(void *kvaddr, enum km_type type)
        preempt_check_resched();
 }
 
+/* This is the same as kmap_atomic() but can map memory that doesn't
+ * have a struct page associated with it.
+ */
+void *kmap_atomic_pfn(unsigned long pfn, enum km_type type)
+{
+       enum fixed_addresses idx;
+       unsigned long vaddr;
+
+       inc_preempt_count();
+
+       idx = type + KM_TYPE_NR*smp_processor_id();
+       vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
+       set_pte(kmap_pte-idx, pfn_pte(pfn, kmap_prot));
+       __flush_tlb_one(vaddr);
+
+       return (void*) vaddr;
+}
+
 struct page *kmap_atomic_to_page(void *ptr)
 {
        unsigned long idx, vaddr = (unsigned long)ptr;