tile: support CONTEXT_TRACKING and thus NOHZ_FULL

Add the TIF_NOHZ flag appropriately.

Add call to user_exit() on entry to do_work_pending() and on entry
to syscalls via do_syscall_trace_enter(), and also the top of
do_syscall_trace_exit() just because it's done in x86.

Add call to user_enter() at the bottom of do_work_pending() once we
have no more work to do before returning to userspace.

Wrap all the trap code in exception_enter() / exception_exit().

Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>

1 files changed, 6 insertions, 3 deletions

diff --git a/arch/tile/include/asm/thread_info.h b/arch/tile/include/asm/thread_info.h
index 96c14c1430d8..6130a3db505b 100644
--- a/arch/tile/include/asm/thread_info.h
+++ b/arch/tile/include/asm/thread_info.h
@@ -126,6 +126,7 @@ extern void _cpu_idle(void);
 #define TIF_NOTIFY_RESUME       8       /* callback before returning to user */
 #define TIF_SYSCALL_TRACEPOINT  9       /* syscall tracepoint instrumentation */
 #define TIF_POLLING_NRFLAG      10      /* idle is polling for TIF_NEED_RESCHED */
+#define TIF_NOHZ                11      /* in adaptive nohz mode */
 
 #define _TIF_SIGPENDING         (1<<TIF_SIGPENDING)
 #define _TIF_NEED_RESCHED       (1<<TIF_NEED_RESCHED)
@@ -138,14 +139,16 @@ extern void _cpu_idle(void);
 #define _TIF_NOTIFY_RESUME      (1<<TIF_NOTIFY_RESUME)
 #define _TIF_SYSCALL_TRACEPOINT (1<<TIF_SYSCALL_TRACEPOINT)
 #define _TIF_POLLING_NRFLAG     (1<<TIF_POLLING_NRFLAG)
+#define _TIF_NOHZ               (1<<TIF_NOHZ)
 
 /* Work to do on any return to user space. */
 #define _TIF_ALLWORK_MASK \
-  (_TIF_SIGPENDING|_TIF_NEED_RESCHED|_TIF_SINGLESTEP|\
-   _TIF_ASYNC_TLB|_TIF_NOTIFY_RESUME)
+        (_TIF_SIGPENDING | _TIF_NEED_RESCHED | _TIF_SINGLESTEP | \
+         _TIF_ASYNC_TLB | _TIF_NOTIFY_RESUME | _TIF_NOHZ)
 
 /* Work to do at syscall entry. */
-#define _TIF_SYSCALL_ENTRY_WORK (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_TRACEPOINT)
+#define _TIF_SYSCALL_ENTRY_WORK \
+        (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_TRACEPOINT | _TIF_NOHZ)
 
 /* Work to do at syscall exit. */
 #define _TIF_SYSCALL_EXIT_WORK (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_TRACEPOINT)