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

Pull powerpc fixes from Benjamin Herrenschmidt:
 "Here are a few fixes for 3.6 that were piling up while I was away or
  busy (I was mostly MIA a week or two before San Diego).

  Some fixes from Anton fixing up issues with our relatively new DSCR
  control feature, and a few other fixes that are either regressions or
  bugs nasty enough to warrant not waiting."

* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
  powerpc: Don't use __put_user() in patch_instruction
  powerpc: Make sure IPI handlers see data written by IPI senders
  powerpc: Restore correct DSCR in context switch
  powerpc: Fix DSCR inheritance in copy_thread()
  powerpc: Keep thread.dscr and thread.dscr_inherit in sync
  powerpc: Update DSCR on all CPUs when writing sysfs dscr_default
  powerpc/powernv: Always go into nap mode when CPU is offline
  powerpc: Give hypervisor decrementer interrupts their own handler
  powerpc/vphn: Fix arch_update_cpu_topology() return value

1 files changed, 17 insertions, 6 deletions

diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 4b01a25e29e..b40e0b4815b 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -370,6 +370,12 @@ _GLOBAL(ret_from_fork)
         li      r3,0
         b       syscall_exit
 
+        .section        ".toc","aw"
+DSCR_DEFAULT:
+        .tc dscr_default[TC],dscr_default
+
+        .section        ".text"
+
 /*
  * This routine switches between two different tasks.  The process
  * state of one is saved on its kernel stack.  Then the state
@@ -509,9 +515,6 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_1T_SEGMENT)
         mr      r1,r8           /* start using new stack pointer */
         std     r7,PACAKSAVE(r13)
 
-        ld      r6,_CCR(r1)
-        mtcrf   0xFF,r6
-
 #ifdef CONFIG_ALTIVEC
 BEGIN_FTR_SECTION
         ld      r0,THREAD_VRSAVE(r4)
@@ -520,14 +523,22 @@ END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
 #endif /* CONFIG_ALTIVEC */
 #ifdef CONFIG_PPC64
 BEGIN_FTR_SECTION
+        lwz     r6,THREAD_DSCR_INHERIT(r4)
+        ld      r7,DSCR_DEFAULT@toc(2)
         ld      r0,THREAD_DSCR(r4)
-        cmpd    r0,r25
-        beq     1f
+        cmpwi   r6,0
+        bne     1f
+        ld      r0,0(r7)
+1:      cmpd    r0,r25
+        beq     2f
         mtspr   SPRN_DSCR,r0
-1:      
+2:
 END_FTR_SECTION_IFSET(CPU_FTR_DSCR)
 #endif
 
+        ld      r6,_CCR(r1)
+        mtcrf   0xFF,r6
+
         /* r3-r13 are destroyed -- Cort */
         REST_8GPRS(14, r1)
         REST_10GPRS(22, r1)