1 files changed, 22 insertions, 9 deletions

diff --git a/arch/powerpc/kernel/crash_dump.c b/arch/powerpc/kernel/crash_dump.c
index e0debcca0bfa..a323c9b32ee1 100644
--- a/arch/powerpc/kernel/crash_dump.c
+++ b/arch/powerpc/kernel/crash_dump.c
@@ -86,6 +86,19 @@ static int __init parse_savemaxmem(char *p)
 }
 __setup("savemaxmem=", parse_savemaxmem);
 
+
+static size_t copy_oldmem_vaddr(void *vaddr, char *buf, size_t csize,
+                               unsigned long offset, int userbuf)
+{
+        if (userbuf) {
+                if (copy_to_user((char __user *)buf, (vaddr + offset), csize))
+                        return -EFAULT;
+        } else
+                memcpy(buf, (vaddr + offset), csize);
+
+        return csize;
+}
+
 /**
  * copy_oldmem_page - copy one page from "oldmem"
  * @pfn: page frame number to be copied
@@ -107,16 +120,16 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
         if (!csize)
                 return 0;
 
-        vaddr = __ioremap(pfn << PAGE_SHIFT, PAGE_SIZE, 0);
+        csize = min(csize, PAGE_SIZE);
 
-        if (userbuf) {
-                if (copy_to_user((char __user *)buf, (vaddr + offset), csize)) {
-                        iounmap(vaddr);
-                        return -EFAULT;
-                }
-        } else
-                memcpy(buf, (vaddr + offset), csize);
+        if (pfn < max_pfn) {
+                vaddr = __va(pfn << PAGE_SHIFT);
+                csize = copy_oldmem_vaddr(vaddr, buf, csize, offset, userbuf);
+        } else {
+                vaddr = __ioremap(pfn << PAGE_SHIFT, PAGE_SIZE, 0);
+                csize = copy_oldmem_vaddr(vaddr, buf, csize, offset, userbuf);
+                iounmap(vaddr);
+        }
 
-        iounmap(vaddr);
         return csize;
 }