Blackfin/ipipe: prepare status bitops for SMP support

Signed-off-by: Philippe Gerum <rpm@xenomai.org>
Signed-off-by: Li Yi <yi.li@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

1 files changed, 67 insertions, 0 deletions

diff --git a/arch/blackfin/kernel/ipipe.c b/arch/blackfin/kernel/ipipe.c
index 5d7382396dc..a77307a4473 100644
--- a/arch/blackfin/kernel/ipipe.c
+++ b/arch/blackfin/kernel/ipipe.c
@@ -335,3 +335,70 @@ void __ipipe_enable_root_irqs_hw(void)
 	__clear_bit(IPIPE_STALL_FLAG, &ipipe_root_cpudom_var(status));
 	bfin_sti(bfin_irq_flags);
 }
+
+/*
+ * We could use standard atomic bitops in the following root status
+ * manipulation routines, but let's prepare for SMP support in the
+ * same move, preventing CPU migration as required.
+ */
+void __ipipe_stall_root(void)
+{
+	unsigned long *p, flags;
+
+	local_irq_save_hw(flags);
+	p = &__ipipe_root_status;
+	__set_bit(IPIPE_STALL_FLAG, p);
+	local_irq_restore_hw(flags);
+}
+EXPORT_SYMBOL(__ipipe_stall_root);
+
+unsigned long __ipipe_test_and_stall_root(void)
+{
+	unsigned long *p, flags;
+	int x;
+
+	local_irq_save_hw(flags);
+	p = &__ipipe_root_status;
+	x = __test_and_set_bit(IPIPE_STALL_FLAG, p);
+	local_irq_restore_hw(flags);
+
+	return x;
+}
+EXPORT_SYMBOL(__ipipe_test_and_stall_root);
+
+unsigned long __ipipe_test_root(void)
+{
+	const unsigned long *p;
+	unsigned long flags;
+	int x;
+
+	local_irq_save_hw_smp(flags);
+	p = &__ipipe_root_status;
+	x = test_bit(IPIPE_STALL_FLAG, p);
+	local_irq_restore_hw_smp(flags);
+
+	return x;
+}
+EXPORT_SYMBOL(__ipipe_test_root);
+
+void __ipipe_lock_root(void)
+{
+	unsigned long *p, flags;
+
+	local_irq_save_hw(flags);
+	p = &__ipipe_root_status;
+	__set_bit(IPIPE_SYNCDEFER_FLAG, p);
+	local_irq_restore_hw(flags);
+}
+EXPORT_SYMBOL(__ipipe_lock_root);
+
+void __ipipe_unlock_root(void)
+{
+	unsigned long *p, flags;
+
+	local_irq_save_hw(flags);
+	p = &__ipipe_root_status;
+	__clear_bit(IPIPE_SYNCDEFER_FLAG, p);
+	local_irq_restore_hw(flags);
+}
+EXPORT_SYMBOL(__ipipe_unlock_root);