Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc

Pull two powerpc fixes from Ben Herrenschmidt:
 "Here's a pair of powerpc fixes for 3.15 which are also going to
  stable.

  One's a fix for building with newer binutils (the problem currently
  only affects the BookE kernels but the affected macro might come back
  into use on BookS platforms at any time).  Unfortunately, the binutils
  maintainer did a backward incompatible change to a construct that we
  use so we have to add Makefile check.

  The other one is a fix for CPUs getting stuck in kexec when running
  single threaded.  Since we routinely use kexec on power (including in
  our newer bootloaders), I deemed that important enough"

* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
  powerpc, kexec: Fix "Processor X is stuck" issue during kexec from ST mode
  powerpc: Fix 64 bit builds with binutils 2.24

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();
         }