Add support for TIF_NOTIFY_IPI on C-SKY. With TIF_NOTIFY_IPI, a sender
sending an IPI to an idle CPU in TIF_POLLING mode will set the
TIF_NOTIFY_IPI flag in the target's idle tasks's thread_info to pull the
CPU out of idle, as opposed to setting TIF_NEED_RESCHED previously. This
avoids spurious calls to schedule_idle() in cases where an IPI does not
necessarily wake up a task on the idle CPU.

Cc: Guo Ren <guo...@kernel.org>
Cc: "Rafael J. Wysocki" <raf...@kernel.org>
Cc: Daniel Lezcano <daniel.lezc...@linaro.org>
Cc: Ingo Molnar <mi...@redhat.com>
Cc: Peter Zijlstra <pet...@infradead.org>
Cc: Juri Lelli <juri.le...@redhat.com>
Cc: Vincent Guittot <vincent.guit...@linaro.org>
Cc: Dietmar Eggemann <dietmar.eggem...@arm.com>
Cc: Steven Rostedt <rost...@goodmis.org>
Cc: Ben Segall <bseg...@google.com>
Cc: Mel Gorman <mgor...@suse.de>
Cc: Daniel Bristot de Oliveira <bris...@redhat.com>
Cc: Valentin Schneider <vschn...@redhat.com>
Cc: K Prateek Nayak <kprateek.na...@amd.com>
Cc: linux-c...@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux...@vger.kernel.org
Signed-off-by: K Prateek Nayak <kprateek.na...@amd.com>
---
 arch/csky/include/asm/thread_info.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/csky/include/asm/thread_info.h 
b/arch/csky/include/asm/thread_info.h
index b5ed788f0c68..9bc7a037c476 100644
--- a/arch/csky/include/asm/thread_info.h
+++ b/arch/csky/include/asm/thread_info.h
@@ -61,6 +61,7 @@ static inline struct thread_info *current_thread_info(void)
 #define TIF_SYSCALL_TRACEPOINT 5       /* syscall tracepoint instrumentation */
 #define TIF_SYSCALL_AUDIT      6       /* syscall auditing */
 #define TIF_NOTIFY_SIGNAL      7       /* signal notifications exist */
+#define TIF_NOTIFY_IPI         8       /* Pending IPI on TIF_POLLLING idle CPU 
*/
 #define TIF_POLLING_NRFLAG     16      /* poll_idle() is TIF_NEED_RESCHED */
 #define TIF_MEMDIE             18      /* is terminating due to OOM killer */
 #define TIF_RESTORE_SIGMASK    20      /* restore signal mask in do_signal() */
@@ -73,6 +74,7 @@ static inline struct thread_info *current_thread_info(void)
 #define _TIF_SYSCALL_TRACEPOINT        (1 << TIF_SYSCALL_TRACEPOINT)
 #define _TIF_SYSCALL_AUDIT     (1 << TIF_SYSCALL_AUDIT)
 #define _TIF_NOTIFY_SIGNAL     (1 << TIF_NOTIFY_SIGNAL)
+#define _TIF_NOTIFY_IPI                (1 << TIF_NOTIFY_IPI)
 #define _TIF_UPROBE            (1 << TIF_UPROBE)
 #define _TIF_POLLING_NRFLAG    (1 << TIF_POLLING_NRFLAG)
 #define _TIF_MEMDIE            (1 << TIF_MEMDIE)
-- 
2.34.1


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