powerpc/cell: Use system_wq in cpufreq_spudemand

With cmwq, there's no reason to use a separate workqueue in
cpufreq_spudemand.  Use system_wq instead.  The work items are already
sync canceled on stop, so it's already guaranteed that no work is
running when spu_gov_exit() is entered.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Dave Jones <davej@redhat.com>
Cc: cpufreq@vger.kernel.org
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index 09e4dea..09d31db 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -265,11 +265,26 @@
 {
 	u64 sst, ust;
 
-	sst = scan_dispatch_log(get_paca()->starttime_user);
-	ust = scan_dispatch_log(get_paca()->starttime);
-	get_paca()->system_time -= sst;
-	get_paca()->user_time -= ust;
-	get_paca()->stolen_time += ust + sst;
+	u8 save_soft_enabled = local_paca->soft_enabled;
+	u8 save_hard_enabled = local_paca->hard_enabled;
+
+	/* We are called early in the exception entry, before
+	 * soft/hard_enabled are sync'ed to the expected state
+	 * for the exception. We are hard disabled but the PACA
+	 * needs to reflect that so various debug stuff doesn't
+	 * complain
+	 */
+	local_paca->soft_enabled = 0;
+	local_paca->hard_enabled = 0;
+
+	sst = scan_dispatch_log(local_paca->starttime_user);
+	ust = scan_dispatch_log(local_paca->starttime);
+	local_paca->system_time -= sst;
+	local_paca->user_time -= ust;
+	local_paca->stolen_time += ust + sst;
+
+	local_paca->soft_enabled = save_soft_enabled;
+	local_paca->hard_enabled = save_hard_enabled;
 }
 
 static inline u64 calculate_stolen_time(u64 stop_tb)