1 files changed, 29 insertions, 0 deletions

diff --git a/arch/ia64/kernel/setup.c b/arch/ia64/kernel/setup.c
index 5015ca1275ca..e9596cd0cdab 100644
--- a/arch/ia64/kernel/setup.c
+++ b/arch/ia64/kernel/setup.c
@@ -239,6 +239,25 @@ __initcall(register_memory);
 
 
 #ifdef CONFIG_KEXEC
+
+/*
+ * This function checks if the reserved crashkernel is allowed on the specific
+ * IA64 machine flavour. Machines without an IO TLB use swiotlb and require
+ * some memory below 4 GB (i.e. in 32 bit area), see the implementation of
+ * lib/swiotlb.c. The hpzx1 architecture has an IO TLB but cannot use that
+ * in kdump case. See the comment in sba_init() in sba_iommu.c.
+ *
+ * So, the only machvec that really supports loading the kdump kernel
+ * over 4 GB is "sn2".
+ */
+static int __init check_crashkernel_memory(unsigned long pbase, size_t size)
+{
+        if (ia64_platform_is("sn2") || ia64_platform_is("uv"))
+                return 1;
+        else
+                return pbase < (1UL << 32);
+}
+
 static void __init setup_crashkernel(unsigned long total, int *n)
 {
         unsigned long long base = 0, size = 0;
@@ -252,6 +271,16 @@ static void __init setup_crashkernel(unsigned long total, int *n)
                         base = kdump_find_rsvd_region(size,
                                         rsvd_region, *n);
                 }
+
+                if (!check_crashkernel_memory(base, size)) {
+                        pr_warning("crashkernel: There would be kdump memory "
+                                "at %ld GB but this is unusable because it "
+                                "must\nbe below 4 GB. Change the memory "
+                                "configuration of the machine.\n",
+                                (unsigned long)(base >> 30));
+                        return;
+                }
+
                 if (base != ~0UL) {
                         printk(KERN_INFO "Reserving %ldMB of memory at %ldMB "
                                         "for crashkernel (System RAM: %ldMB)\n",