powerpc: Fix /dev/oldmem interface for kdump

[pandora-kernel.git] / arch / powerpc / kernel / crash_dump.c

diff --git a/arch/powerpc/kernel/crash_dump.c b/arch/powerpc/kernel/crash_dump.c
index e0debcc..a323c9b 100644 (file)
--- 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;
 }