6 files changed, 29 insertions, 35 deletions

diff --git a/arch/powerpc/include/asm/paca.h b/arch/powerpc/include/asm/paca.h
index 8e956a0b6e85..bb0bd25f20d0 100644
--- a/arch/powerpc/include/asm/paca.h
+++ b/arch/powerpc/include/asm/paca.h
@@ -92,7 +92,10 @@ struct paca_struct {
         struct slb_shadow *slb_shadow_ptr;
         struct dtl_entry *dispatch_log;
         struct dtl_entry *dispatch_log_end;
+#endif /* CONFIG_PPC_STD_MMU_64 */
+        u64 dscr_default;               /* per-CPU default DSCR */
 
+#ifdef CONFIG_PPC_STD_MMU_64
         /*
          * Now, starting in cacheline 2, the exception save areas
          */
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index dba8140ebc20..cba2697406b7 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -247,6 +247,7 @@ int main(void)
 #endif
         DEFINE(PACAHWCPUID, offsetof(struct paca_struct, hw_cpu_id));
         DEFINE(PACAKEXECSTATE, offsetof(struct paca_struct, kexec_state));
+        DEFINE(PACA_DSCR, offsetof(struct paca_struct, dscr_default));
         DEFINE(PACA_STARTTIME, offsetof(struct paca_struct, starttime));
         DEFINE(PACA_STARTTIME_USER, offsetof(struct paca_struct, starttime_user));
         DEFINE(PACA_USER_TIME, offsetof(struct paca_struct, user_time));
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 9fde8a1bf1e1..911d45366f59 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -387,12 +387,6 @@ _GLOBAL(ret_from_kernel_thread)
         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
@@ -577,11 +571,10 @@ END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
 #ifdef CONFIG_PPC64
 BEGIN_FTR_SECTION
         lwz     r6,THREAD_DSCR_INHERIT(r4)
-        ld      r7,DSCR_DEFAULT@toc(2)
         ld      r0,THREAD_DSCR(r4)
         cmpwi   r6,0
         bne     1f
-        ld      r0,0(r7)
+        ld      r0,PACA_DSCR(r13)
 1:
 BEGIN_FTR_SECTION_NESTED(70)
         mfspr   r8, SPRN_FSCR
diff --git a/arch/powerpc/kernel/sysfs.c b/arch/powerpc/kernel/sysfs.c
index e2a1d6fb3297..67fd2fd2620a 100644
--- a/arch/powerpc/kernel/sysfs.c
+++ b/arch/powerpc/kernel/sysfs.c
@@ -484,7 +484,6 @@ SYSFS_PMCSETUP(pmc8, SPRN_PMC8);
 SYSFS_PMCSETUP(mmcra, SPRN_MMCRA);
 SYSFS_SPRSETUP(purr, SPRN_PURR);
 SYSFS_SPRSETUP(spurr, SPRN_SPURR);
-SYSFS_SPRSETUP(dscr, SPRN_DSCR);
 SYSFS_SPRSETUP(pir, SPRN_PIR);
 
 /*
@@ -494,12 +493,27 @@ SYSFS_SPRSETUP(pir, SPRN_PIR);
 */
 static DEVICE_ATTR(mmcra, 0600, show_mmcra, store_mmcra);
 static DEVICE_ATTR(spurr, 0400, show_spurr, NULL);
-static DEVICE_ATTR(dscr, 0600, show_dscr, store_dscr);
 static DEVICE_ATTR(purr, 0400, show_purr, store_purr);
 static DEVICE_ATTR(pir, 0400, show_pir, NULL);
 
-unsigned long dscr_default = 0;
-EXPORT_SYMBOL(dscr_default);
+static unsigned long dscr_default;
+
+static void read_dscr(void *val)
+{
+        *(unsigned long *)val = get_paca()->dscr_default;
+}
+
+static void write_dscr(void *val)
+{
+        get_paca()->dscr_default = *(unsigned long *)val;
+        if (!current->thread.dscr_inherit) {
+                current->thread.dscr = *(unsigned long *)val;
+                mtspr(SPRN_DSCR, *(unsigned long *)val);
+        }
+}
+
+SYSFS_SPRSETUP_SHOW_STORE(dscr);
+static DEVICE_ATTR(dscr, 0600, show_dscr, store_dscr);
 
 static void add_write_permission_dev_attr(struct device_attribute *attr)
 {
@@ -512,14 +526,6 @@ static ssize_t show_dscr_default(struct device *dev,
         return sprintf(buf, "%lx\n", dscr_default);
 }
 
-static void update_dscr(void *dummy)
-{
-        if (!current->thread.dscr_inherit) {
-                current->thread.dscr = dscr_default;
-                mtspr(SPRN_DSCR, dscr_default);
-        }
-}
-
 static ssize_t __used store_dscr_default(struct device *dev,
                 struct device_attribute *attr, const char *buf,
                 size_t count)
@@ -532,7 +538,7 @@ static ssize_t __used store_dscr_default(struct device *dev,
                 return -EINVAL;
         dscr_default = val;
 
-        on_each_cpu(update_dscr, NULL, 1);
+        on_each_cpu(write_dscr, &val, 1);
 
         return count;
 }
diff --git a/arch/powerpc/kernel/tm.S b/arch/powerpc/kernel/tm.S
index ee061c3715de..2a324f4cb1b9 100644
--- a/arch/powerpc/kernel/tm.S
+++ b/arch/powerpc/kernel/tm.S
@@ -78,12 +78,6 @@ _GLOBAL(tm_abort)
         TABORT(R3)
         blr
 
-        .section        ".toc","aw"
-DSCR_DEFAULT:
-        .tc dscr_default[TC],dscr_default
-
-        .section        ".text"
-
 /* void tm_reclaim(struct thread_struct *thread,
  *                 unsigned long orig_msr,
  *                 uint8_t cause)
@@ -298,9 +292,8 @@ dont_backup_fp:
         mtlr    r0
         ld      r2, STK_GOT(r1)
 
-        /* Load system default DSCR */
-        ld      r4, DSCR_DEFAULT@toc(r2)
-        ld      r0, 0(r4)
+        /* Load CPU's default DSCR */
+        ld      r0, PACA_DSCR(r13)
         mtspr   SPRN_DSCR, r0
 
         blr
@@ -479,9 +472,8 @@ restore_gprs:
         mtlr    r0
         ld      r2, STK_GOT(r1)
 
-        /* Load system default DSCR */
-        ld      r4, DSCR_DEFAULT@toc(r2)
-        ld      r0, 0(r4)
+        /* Load CPU's default DSCR */
+        ld      r0, PACA_DSCR(r13)
         mtspr   SPRN_DSCR, r0
 
         blr
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index 9f0ad718e476..12f4ce5b4f78 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -286,8 +286,7 @@ kvm_start_guest:
         beq     kvm_no_guest
 
         /* Set HSTATE_DSCR(r13) to something sensible */
-        LOAD_REG_ADDR(r6, dscr_default)
-        ld      r6, 0(r6)
+        ld      r6, PACA_DSCR(r13)
         std     r6, HSTATE_DSCR(r13)
 
         bl      kvmppc_hv_entry