[MIPS] SMTC: Fix holes in SMTC and FPU affinity support.

Signed-off-by: Kevin D. Kissell <kevink@paralogos.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

3 files changed, 14 insertions, 13 deletions

diff --git a/arch/mips/kernel/mips-mt-fpaff.c b/arch/mips/kernel/mips-mt-fpaff.c
index df4d3f2f740c..dc9eb72ed9de 100644
--- a/arch/mips/kernel/mips-mt-fpaff.c
+++ b/arch/mips/kernel/mips-mt-fpaff.c
@@ -159,7 +159,7 @@ __setup("fpaff=", fpaff_thresh);
 /*
  * FPU Use Factor empirically derived from experiments on 34K
  */
-#define FPUSEFACTOR 333
+#define FPUSEFACTOR 2000
 
 static __init int mt_fp_affinity_init(void)
 {
diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c
index ce7684335a41..22fc19bbe87f 100644
--- a/arch/mips/kernel/process.c
+++ b/arch/mips/kernel/process.c
@@ -55,7 +55,7 @@ void __noreturn cpu_idle(void)
         while (1) {
                 tick_nohz_stop_sched_tick(1);
                 while (!need_resched()) {
-#ifdef CONFIG_SMTC_IDLE_HOOK_DEBUG
+#ifdef CONFIG_MIPS_MT_SMTC
                         extern void smtc_idle_loop_hook(void);
 
                         smtc_idle_loop_hook();
@@ -145,19 +145,18 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
          */
         p->thread.cp0_status = read_c0_status() & ~(ST0_CU2|ST0_CU1);
         childregs->cp0_status &= ~(ST0_CU2|ST0_CU1);
+
+#ifdef CONFIG_MIPS_MT_SMTC
+        /*
+         * SMTC restores TCStatus after Status, and the CU bits
+         * are aliased there.
+         */
+        childregs->cp0_tcstatus &= ~(ST0_CU2|ST0_CU1);
+#endif
         clear_tsk_thread_flag(p, TIF_USEDFPU);
 
 #ifdef CONFIG_MIPS_MT_FPAFF
         clear_tsk_thread_flag(p, TIF_FPUBOUND);
-
-        /*
-         * FPU affinity support is cleaner if we track the
-         * user-visible CPU affinity from the very beginning.
-         * The generic cpus_allowed mask will already have
-         * been copied from the parent before copy_thread
-         * is invoked.
-         */
-        p->thread.user_cpus_allowed = p->cpus_allowed;
 #endif /* CONFIG_MIPS_MT_FPAFF */
 
         if (clone_flags & CLONE_SETTLS)
diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index 5fd0cd020af5..b602ac6eb47d 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -825,8 +825,10 @@ static void mt_ase_fp_affinity(void)
                 if (cpus_intersects(current->cpus_allowed, mt_fpu_cpumask)) {
                         cpumask_t tmask;
 
-                        cpus_and(tmask, current->thread.user_cpus_allowed,
-                                 mt_fpu_cpumask);
+                        current->thread.user_cpus_allowed
+                                = current->cpus_allowed;
+                        cpus_and(tmask, current->cpus_allowed,
+                                mt_fpu_cpumask);
                         set_cpus_allowed(current, tmask);
                         set_thread_flag(TIF_FPUBOUND);
                 }