1 files changed, 55 insertions, 23 deletions

diff --git a/arch/x86/include/asm/preempt.h b/arch/x86/include/asm/preempt.h
index ec1f3c651150..578441db09f0 100644
--- a/arch/x86/include/asm/preempt.h
+++ b/arch/x86/include/asm/preempt.h
@@ -1,11 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __ASM_PREEMPT_H
 #define __ASM_PREEMPT_H
 
 #include <asm/rmwcc.h>
 #include <asm/percpu.h>
-#include <linux/thread_info.h>
 
-DECLARE_PER_CPU(int, __preempt_count);
+#include <linux/static_call_types.h>
+
+DECLARE_PER_CPU_CACHE_HOT(int, __preempt_count);
+
+/* We use the MSB mostly because its available */
+#define PREEMPT_NEED_RESCHED	0x80000000
 
 /*
  * We use the PREEMPT_NEED_RESCHED bit as an inverted NEED_RESCHED such
@@ -26,11 +31,11 @@ static __always_inline void preempt_count_set(int pc)
 {
 	int old, new;
 
+	old = raw_cpu_read_4(__preempt_count);
 	do {
-		old = raw_cpu_read_4(__preempt_count);
 		new = (old & PREEMPT_NEED_RESCHED) |
 			(pc & ~PREEMPT_NEED_RESCHED);
-	} while (raw_cpu_cmpxchg_4(__preempt_count, old, new) != old);
+	} while (!raw_cpu_try_cmpxchg_4(__preempt_count, &old, new));
 }
 
 /*
@@ -39,7 +44,7 @@ static __always_inline void preempt_count_set(int pc)
 #define init_task_preempt_count(p) do { } while (0)
 
 #define init_idle_preempt_count(p, cpu) do { \
-	per_cpu(__preempt_count, (cpu)) = PREEMPT_ENABLED; \
+	per_cpu(__preempt_count, (cpu)) = PREEMPT_DISABLED; \
 } while (0)
 
 /*
@@ -87,7 +92,8 @@ static __always_inline void __preempt_count_sub(int val)
  */
 static __always_inline bool __preempt_count_dec_and_test(void)
 {
-	GEN_UNARY_RMWcc("decl", __preempt_count, __percpu_arg(0), e);
+	return GEN_UNARY_RMWcc("decl", __my_cpu_var(__preempt_count), e,
+			       __percpu_arg([var]));
 }
 
 /*
@@ -98,22 +104,48 @@ static __always_inline bool should_resched(int preempt_offset)
 	return unlikely(raw_cpu_read_4(__preempt_count) == preempt_offset);
 }
 
-#ifdef CONFIG_PREEMPT
-  extern asmlinkage void ___preempt_schedule(void);
-# define __preempt_schedule()					\
-({								\
-	register void *__sp asm(_ASM_SP);			\
-	asm volatile ("call ___preempt_schedule" : "+r"(__sp));	\
-})
-
-  extern asmlinkage void preempt_schedule(void);
-  extern asmlinkage void ___preempt_schedule_notrace(void);
-# define __preempt_schedule_notrace()					\
-({									\
-	register void *__sp asm(_ASM_SP);				\
-	asm volatile ("call ___preempt_schedule_notrace" : "+r"(__sp));	\
-})
-  extern asmlinkage void preempt_schedule_notrace(void);
-#endif
+#ifdef CONFIG_PREEMPTION
+
+extern asmlinkage void preempt_schedule(void);
+extern asmlinkage void preempt_schedule_thunk(void);
+
+#define preempt_schedule_dynamic_enabled	preempt_schedule_thunk
+#define preempt_schedule_dynamic_disabled	NULL
+
+extern asmlinkage void preempt_schedule_notrace(void);
+extern asmlinkage void preempt_schedule_notrace_thunk(void);
+
+#define preempt_schedule_notrace_dynamic_enabled	preempt_schedule_notrace_thunk
+#define preempt_schedule_notrace_dynamic_disabled	NULL
+
+#ifdef CONFIG_PREEMPT_DYNAMIC
+
+DECLARE_STATIC_CALL(preempt_schedule, preempt_schedule_dynamic_enabled);
+
+#define __preempt_schedule() \
+do { \
+	__STATIC_CALL_MOD_ADDRESSABLE(preempt_schedule); \
+	asm volatile ("call " STATIC_CALL_TRAMP_STR(preempt_schedule) : ASM_CALL_CONSTRAINT); \
+} while (0)
+
+DECLARE_STATIC_CALL(preempt_schedule_notrace, preempt_schedule_notrace_dynamic_enabled);
+
+#define __preempt_schedule_notrace() \
+do { \
+	__STATIC_CALL_MOD_ADDRESSABLE(preempt_schedule_notrace); \
+	asm volatile ("call " STATIC_CALL_TRAMP_STR(preempt_schedule_notrace) : ASM_CALL_CONSTRAINT); \
+} while (0)
+
+#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 */