[POWERPC] Initialize paca->current earlier

Currently, we initialize the "current" pointer in the PACA (which
is used by the "current" macro in the kernel) before calling
setup_system(). That means that early_setup() is called with
current still "NULL" which is -not- a good idea. It happens to
work so far but breaks with lockdep when early code calls printk.

This changes it so that all PACAs are statically initialized with
__current pointing to the init task. For non-0 CPUs, this is fixed
up before use.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

2 files changed, 1 insertions, 4 deletions

diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
index 43a38d89eafc..44229c3749ac 100644
--- a/arch/powerpc/kernel/head_64.S
+++ b/arch/powerpc/kernel/head_64.S
@@ -1521,10 +1521,6 @@ _INIT_GLOBAL(start_here_common)
         li      r0,0
         stdu    r0,-STACK_FRAME_OVERHEAD(r1)
 
-        /* ptr to current */
-        LOAD_REG_IMMEDIATE(r4, init_task)
-        std     r4,PACACURRENT(r13)
-
         /* Load the TOC */
         ld      r2,PACATOC(r13)
         std     r1,PACAKSAVE(r13)
diff --git a/arch/powerpc/kernel/paca.c b/arch/powerpc/kernel/paca.c
index 867b22d17385..ac163bd46cfd 100644
--- a/arch/powerpc/kernel/paca.c
+++ b/arch/powerpc/kernel/paca.c
@@ -73,6 +73,7 @@ struct slb_shadow slb_shadow[] __cacheline_aligned = {
         .kernel_toc = (unsigned long)(&__toc_start) + 0x8000UL,             \
         .hw_cpu_id = 0xffff,                                                \
         .slb_shadow_ptr = &slb_shadow[number],                              \
+        .__current = &init_task,                                            \
 }
 
 struct paca_struct paca[] = {