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

* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc:
  [POWERPC] Bypass hcall stats until cpu features have run
  [POWERPC] Avoid hypervisor statistics calculation in real mode
  [POWERPC] Fix atomicity of TIF update in flush_thread()

4 files changed, 64 insertions, 4 deletions

diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index f3d4dd580dd6..e53b2988d1bf 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -465,8 +465,13 @@ void flush_thread(void)
 #ifdef CONFIG_PPC64
         struct thread_info *t = current_thread_info();
 
-        if (t->flags & _TIF_ABI_PENDING)
-                t->flags ^= (_TIF_ABI_PENDING | _TIF_32BIT);
+        if (test_ti_thread_flag(t, TIF_ABI_PENDING)) {
+                clear_ti_thread_flag(t, TIF_ABI_PENDING);
+                if (test_ti_thread_flag(t, TIF_32BIT))
+                        clear_ti_thread_flag(t, TIF_32BIT);
+                else
+                        set_ti_thread_flag(t, TIF_32BIT);
+        }
 #endif
 
         discard_lazy_cpu_state();
diff --git a/arch/powerpc/platforms/pseries/hvCall.S b/arch/powerpc/platforms/pseries/hvCall.S
index 5c7e38789897..c1427b3634ec 100644
--- a/arch/powerpc/platforms/pseries/hvCall.S
+++ b/arch/powerpc/platforms/pseries/hvCall.S
@@ -30,9 +30,14 @@ END_FTR_SECTION_IFSET(CPU_FTR_PURR);
         
 /*
  * postcall is performed immediately before function return which
- * allows liberal use of volatile registers.
+ * allows liberal use of volatile registers.  We branch around this
+ * in early init (eg when populating the MMU hashtable) by using an
+ * unconditional cpu feature.
  */
 #define HCALL_INST_POSTCALL                                     \
+BEGIN_FTR_SECTION;                                              \
+        b       1f;                                             \
+END_FTR_SECTION(0, 1);                                          \
         ld      r4,STK_PARM(r3)(r1);    /* validate opcode */   \
         cmpldi  cr7,r4,MAX_HCALL_OPCODE;                        \
         bgt-    cr7,1f;                                         \
@@ -123,6 +128,40 @@ _GLOBAL(plpar_hcall)
 
         blr                             /* return r3 = status */
 
+/*
+ * plpar_hcall_raw can be called in real mode. kexec/kdump need some
+ * hypervisor calls to be executed in real mode. So plpar_hcall_raw
+ * does not access the per cpu hypervisor call statistics variables,
+ * since these variables may not be present in the RMO region.
+ */
+_GLOBAL(plpar_hcall_raw)
+        HMT_MEDIUM
+
+        mfcr    r0
+        stw     r0,8(r1)
+
+        std     r4,STK_PARM(r4)(r1)     /* Save ret buffer */
+
+        mr      r4,r5
+        mr      r5,r6
+        mr      r6,r7
+        mr      r7,r8
+        mr      r8,r9
+        mr      r9,r10
+
+        HVSC                            /* invoke the hypervisor */
+
+        ld      r12,STK_PARM(r4)(r1)
+        std     r4,  0(r12)
+        std     r5,  8(r12)
+        std     r6, 16(r12)
+        std     r7, 24(r12)
+
+        lwz     r0,8(r1)
+        mtcrf   0xff,r0
+
+        blr                             /* return r3 = status */
+
 _GLOBAL(plpar_hcall9)
         HMT_MEDIUM
 
diff --git a/arch/powerpc/platforms/pseries/lpar.c b/arch/powerpc/platforms/pseries/lpar.c
index 7496005566ef..843ee9643211 100644
--- a/arch/powerpc/platforms/pseries/lpar.c
+++ b/arch/powerpc/platforms/pseries/lpar.c
@@ -378,7 +378,7 @@ static void pSeries_lpar_hptab_clear(void)
 
         /* TODO: Use bulk call */
         for (i = 0; i < hpte_count; i++)
-                plpar_pte_remove(0, i, 0, &dummy1, &dummy2);
+                plpar_pte_remove_raw(0, i, 0, &dummy1, &dummy2);
 }
 
 /*
diff --git a/arch/powerpc/platforms/pseries/plpar_wrappers.h b/arch/powerpc/platforms/pseries/plpar_wrappers.h
index 3eb7b294d92f..2e4d10c9eea8 100644
--- a/arch/powerpc/platforms/pseries/plpar_wrappers.h
+++ b/arch/powerpc/platforms/pseries/plpar_wrappers.h
@@ -78,6 +78,22 @@ static inline long plpar_pte_remove(unsigned long flags, unsigned long ptex,
         return rc;
 }
 
+/* plpar_pte_remove_raw can be called in real mode. It calls plpar_hcall_raw */
+static inline long plpar_pte_remove_raw(unsigned long flags, unsigned long ptex,
+                unsigned long avpn, unsigned long *old_pteh_ret,
+                unsigned long *old_ptel_ret)
+{
+        long rc;
+        unsigned long retbuf[PLPAR_HCALL_BUFSIZE];
+
+        rc = plpar_hcall_raw(H_REMOVE, retbuf, flags, ptex, avpn);
+
+        *old_pteh_ret = retbuf[0];
+        *old_ptel_ret = retbuf[1];
+
+        return rc;
+}
+
 static inline long plpar_pte_read(unsigned long flags, unsigned long ptex,
                 unsigned long *old_pteh_ret, unsigned long *old_ptel_ret)
 {