[POWERPC] ppc64: support CONFIG_DEBUG_PREEMPT

Add CONFIG_DEBUG_PREEMPT support to ppc64: it was useful for testing
get_paca() preemption.  Cheat a little, just use debug_smp_processor_id()
in the debug version of get_paca(): it contains all the right checks and
reporting, though get_paca() doesn't really use smp_processor_id().

Use local_paca for what might have been called __raw_get_paca().
Silence harmless warnings from io.h and lparcfg.c with local_paca -
it is okay for iseries_lparcfg_data to be referencing shared_proc
with preemption enabled: all cpus should show the same value for
shared_proc.

Why do other architectures need TRACE_IRQFLAGS_SUPPORT for DEBUG_PREEMPT?
I don't know, ppc64 appears to get along fine without it.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/arch/powerpc/kernel/lparcfg.c b/arch/powerpc/kernel/lparcfg.c
index 6444eaa30a2f..ff781b2eddec 100644
--- a/arch/powerpc/kernel/lparcfg.c
+++ b/arch/powerpc/kernel/lparcfg.c
@@ -77,7 +77,7 @@ static int iseries_lparcfg_data(struct seq_file *m, void *v)
 	int processors, max_processors;
 	unsigned long purr = get_purr();
 
-	shared = (int)(get_lppaca()->shared_proc);
+	shared = (int)(local_paca->lppaca_ptr->shared_proc);
 
 	seq_printf(m, "system_active_processors=%d\n",
 		   (int)HvLpConfig_getSystemPhysicalProcessors());