4 files changed, 18 insertions, 3 deletions

diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
index 4c0cedf4e2c7..ce4c68a4a823 100644
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile
@@ -150,7 +150,9 @@ endif
 
 CFLAGS-$(CONFIG_TUNE_CELL) += $(call cc-option,-mtune=cell)
 
-KBUILD_CPPFLAGS += -Iarch/$(ARCH)
+asinstr := $(call as-instr,lis 9$(comma)foo@high,-DHAVE_AS_ATHIGH=1)
+
+KBUILD_CPPFLAGS += -Iarch/$(ARCH) $(asinstr)
 KBUILD_AFLAGS   += -Iarch/$(ARCH)
 KBUILD_CFLAGS   += -msoft-float -pipe -Iarch/$(ARCH) $(CFLAGS-y)
 CPP             = $(CC) -E $(KBUILD_CFLAGS)
diff --git a/arch/powerpc/include/asm/ppc_asm.h b/arch/powerpc/include/asm/ppc_asm.h
index 6586a40a46ce..cded7c1278ef 100644
--- a/arch/powerpc/include/asm/ppc_asm.h
+++ b/arch/powerpc/include/asm/ppc_asm.h
@@ -318,11 +318,16 @@ n:
         addi    reg,reg,(name - 0b)@l;
 
 #ifdef __powerpc64__
+#ifdef HAVE_AS_ATHIGH
+#define __AS_ATHIGH high
+#else
+#define __AS_ATHIGH h
+#endif
 #define LOAD_REG_IMMEDIATE(reg,expr)            \
         lis     reg,(expr)@highest;             \
         ori     reg,reg,(expr)@higher;  \
         rldicr  reg,reg,32,31;          \
-        oris    reg,reg,(expr)@h;               \
+        oris    reg,reg,(expr)@__AS_ATHIGH;     \
         ori     reg,reg,(expr)@l;
 
 #define LOAD_REG_ADDR(reg,name)                 \
diff --git a/arch/powerpc/kernel/machine_kexec_64.c b/arch/powerpc/kernel/machine_kexec_64.c
index 59d229a2a3e0..879b3aacac32 100644
--- a/arch/powerpc/kernel/machine_kexec_64.c
+++ b/arch/powerpc/kernel/machine_kexec_64.c
@@ -237,7 +237,7 @@ static void wake_offline_cpus(void)
                 if (!cpu_online(cpu)) {
                         printk(KERN_INFO "kexec: Waking offline cpu %d.\n",
                                cpu);
-                        cpu_up(cpu);
+                        WARN_ON(cpu_up(cpu));
                 }
         }
 }
diff --git a/kernel/kexec.c b/kernel/kexec.c
index c8380ad203bc..28c57069ef68 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -1683,6 +1683,14 @@ int kernel_kexec(void)
                 kexec_in_progress = true;
                 kernel_restart_prepare(NULL);
                 migrate_to_reboot_cpu();
+
+                /*
+                 * migrate_to_reboot_cpu() disables CPU hotplug assuming that
+                 * no further code needs to use CPU hotplug (which is true in
+                 * the reboot case). However, the kexec path depends on using
+                 * CPU hotplug again; so re-enable it here.
+                 */
+                cpu_hotplug_enable();
                 printk(KERN_EMERG "Starting new kernel\n");
                 machine_shutdown();
         }