Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block

[cascardo/linux.git] / drivers / xen / balloon.c

diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
index 2b17ad5..43f9f02 100644 (file)
--- a/drivers/xen/balloon.c
+++ b/drivers/xen/balloon.c
@@ -412,8 +412,16 @@ static int __init balloon_init(void)
 
        register_balloon(&balloon_sysdev);
 
-       /* Initialise the balloon with excess memory space. */
-       extra_pfn_end = min(e820_end_of_ram_pfn(),
+       /*
+        * Initialise the balloon with excess memory space.  We need
+        * to make sure we don't add memory which doesn't exist or
+        * logically exist.  The E820 map can be trimmed to be smaller
+        * than the amount of physical memory due to the mem= command
+        * line parameter.  And if this is a 32-bit non-HIGHMEM kernel
+        * on a system with memory which requires highmem to access,
+        * don't try to use it.
+        */
+       extra_pfn_end = min(min(max_pfn, e820_end_of_ram_pfn()),
                            (unsigned long)PFN_DOWN(xen_extra_mem_start + xen_extra_mem_size));
        for (pfn = PFN_UP(xen_extra_mem_start);
             pfn < extra_pfn_end;