[tip: sched/core] sched,x86: Allow !PREEMPT_DYNAMIC

[tip-bot2 for Peter Zijlstra]

The following commit has been merged into the sched/core branch of tip:

Commit-ID:     c5e6fc08feb2b88dc5dac2f3c817e1c2a4cafda4
Gitweb:        https://git.kernel.org/tip/c5e6fc08feb2b88dc5dac2f3c817e1c2a4cafda4
Author:        Peter Zijlstra <peterz@xxxxxxxxxxxxx>
AuthorDate:    Tue, 09 Feb 2021 22:02:33 +01:00
Committer:     Ingo Molnar <mingo@xxxxxxxxxx>
CommitterDate: Wed, 17 Feb 2021 14:12:43 +01:00

sched,x86: Allow !PREEMPT_DYNAMIC

Allow building x86 with PREEMPT_DYNAMIC=n, this is needed for
PREEMPT_RT as it makes no sense to not have full preemption on
PREEMPT_RT.

Fixes: 8c98e8cf723c ("preempt/dynamic: Provide preempt_schedule[_notrace]() static calls")
Reported-by: Mike Galbraith <efault@xxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Tested-by: Mike Galbraith <efault@xxxxxx>
Link: https://lkml.kernel.org/r/YCK1+JyFNxQnWeXK@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
---
 arch/x86/include/asm/preempt.h | 24 ++++++++++++++++++------
 1 file changed, 18 insertions(+), 6 deletions(-)

diff --git a/arch/x86/include/asm/preempt.h b/arch/x86/include/asm/preempt.h
index 0aa96f8..f8cb8af 100644
--- a/arch/x86/include/asm/preempt.h
+++ b/arch/x86/include/asm/preempt.h
@@ -110,6 +110,13 @@ extern asmlinkage void preempt_schedule_thunk(void);
 
 #define __preempt_schedule_func preempt_schedule_thunk
 
+extern asmlinkage void preempt_schedule_notrace(void);
+extern asmlinkage void preempt_schedule_notrace_thunk(void);
+
+#define __preempt_schedule_notrace_func preempt_schedule_notrace_thunk
+
+#ifdef CONFIG_PREEMPT_DYNAMIC
+
 DECLARE_STATIC_CALL(preempt_schedule, __preempt_schedule_func);
 
 #define __preempt_schedule() \
@@ -118,11 +125,6 @@ do { \
 	asm volatile ("call " STATIC_CALL_TRAMP_STR(preempt_schedule) : ASM_CALL_CONSTRAINT); \
 } while (0)
 
-extern asmlinkage void preempt_schedule_notrace(void);
-extern asmlinkage void preempt_schedule_notrace_thunk(void);
-
-#define __preempt_schedule_notrace_func preempt_schedule_notrace_thunk
-
 DECLARE_STATIC_CALL(preempt_schedule_notrace, __preempt_schedule_notrace_func);
 
 #define __preempt_schedule_notrace() \
@@ -131,6 +133,16 @@ do { \
 	asm volatile ("call " STATIC_CALL_TRAMP_STR(preempt_schedule_notrace) : ASM_CALL_CONSTRAINT); \
 } while (0)
 
-#endif
+#else /* PREEMPT_DYNAMIC */
+
+#define __preempt_schedule() \
+	asm volatile ("call preempt_schedule_thunk" : ASM_CALL_CONSTRAINT);
+
+#define __preempt_schedule_notrace() \
+	asm volatile ("call preempt_schedule_notrace_thunk" : ASM_CALL_CONSTRAINT);
+
+#endif /* PREEMPT_DYNAMIC */
+
+#endif /* PREEMPTION */
 
 #endif /* __ASM_PREEMPT_H */