Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752110AbaLISsY (ORCPT ); Tue, 9 Dec 2014 13:48:24 -0500 Received: from mail-ie0-f182.google.com ([209.85.223.182]:55657 "EHLO mail-ie0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751970AbaLISsW (ORCPT ); Tue, 9 Dec 2014 13:48:22 -0500 From: Pranith Kumar To: Martin Schwidefsky , Heiko Carstens , linux390@de.ibm.com (supporter:S390), Lai Jiangshan , "Paul E. McKenney" , Josh Triplett , Steven Rostedt , Mathieu Desnoyers , Christian Borntraeger , Jens Freimann , linux-s390@vger.kernel.org (open list:S390), linux-kernel@vger.kernel.org (open list) Subject: [PATCH] srcu: Isolate srcu sections using CONFIG_SRCU Date: Tue, 9 Dec 2014 13:48:21 -0500 Message-Id: <1418150903-15760-1-git-send-email-bobby.prani@gmail.com> X-Mailer: git-send-email 1.9.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Isolate the SRCU functions and data structures within CONFIG_SRCU so that there is a compile time failure if srcu is used when not enabled. This was decided to be better than waiting until link time for a failure to occur. Also make including kvm_host.h conditional on CONFIG_KVM being enabled. This prevents build failures as KVM is dependent on SRCU. Signed-off-by: Pranith Kumar CC: Paul E. McKenney CC: Josh Triplett CC: Lai Jiangshan Signed-off-by: Paul E. McKenney --- arch/s390/kernel/asm-offsets.c | 7 ++++++- include/linux/notifier.h | 47 ++++++++++++++++++++++++------------------ include/linux/srcu.h | 6 +++++- 3 files changed, 38 insertions(+), 22 deletions(-) diff --git a/arch/s390/kernel/asm-offsets.c b/arch/s390/kernel/asm-offsets.c index ef279a1..2813a3c 100644 --- a/arch/s390/kernel/asm-offsets.c +++ b/arch/s390/kernel/asm-offsets.c @@ -7,12 +7,15 @@ #define ASM_OFFSETS_C #include -#include #include #include #include #include +#if IS_ENABLED(CONFIG_KVM) +#include +#endif + /* * Make sure that the compiler is new enough. We want a compiler that * is known to work with the "Q" assembler constraint. @@ -182,8 +185,10 @@ int main(void) DEFINE(__LC_PGM_TDB, offsetof(struct _lowcore, pgm_tdb)); DEFINE(__THREAD_trap_tdb, offsetof(struct task_struct, thread.trap_tdb)); DEFINE(__GMAP_ASCE, offsetof(struct gmap, asce)); +#if IS_ENABLED(CONFIG_KVM) DEFINE(__SIE_PROG0C, offsetof(struct kvm_s390_sie_block, prog0c)); DEFINE(__SIE_PROG20, offsetof(struct kvm_s390_sie_block, prog20)); +#endif /* CONFIG_KVM */ #endif /* CONFIG_32BIT */ return 0; } diff --git a/include/linux/notifier.h b/include/linux/notifier.h index d14a4c3..fe4f02a 100644 --- a/include/linux/notifier.h +++ b/include/linux/notifier.h @@ -47,6 +47,8 @@ * runtime initialization. */ +struct notifier_block; + typedef int (*notifier_fn_t)(struct notifier_block *nb, unsigned long action, void *data); @@ -70,12 +72,6 @@ struct raw_notifier_head { struct notifier_block __rcu *head; }; -struct srcu_notifier_head { - struct mutex mutex; - struct srcu_struct srcu; - struct notifier_block __rcu *head; -}; - #define ATOMIC_INIT_NOTIFIER_HEAD(name) do { \ spin_lock_init(&(name)->lock); \ (name)->head = NULL; \ @@ -88,11 +84,6 @@ struct srcu_notifier_head { (name)->head = NULL; \ } while (0) -/* srcu_notifier_heads must be initialized and cleaned up dynamically */ -extern void srcu_init_notifier_head(struct srcu_notifier_head *nh); -#define srcu_cleanup_notifier_head(name) \ - cleanup_srcu_struct(&(name)->srcu); - #define ATOMIC_NOTIFIER_INIT(name) { \ .lock = __SPIN_LOCK_UNLOCKED(name.lock), \ .head = NULL } @@ -101,7 +92,6 @@ extern void srcu_init_notifier_head(struct srcu_notifier_head *nh); .head = NULL } #define RAW_NOTIFIER_INIT(name) { \ .head = NULL } -/* srcu_notifier_heads cannot be initialized statically */ #define ATOMIC_NOTIFIER_HEAD(name) \ struct atomic_notifier_head name = \ @@ -121,8 +111,6 @@ extern int blocking_notifier_chain_register(struct blocking_notifier_head *nh, struct notifier_block *nb); extern int raw_notifier_chain_register(struct raw_notifier_head *nh, struct notifier_block *nb); -extern int srcu_notifier_chain_register(struct srcu_notifier_head *nh, - struct notifier_block *nb); extern int blocking_notifier_chain_cond_register( struct blocking_notifier_head *nh, @@ -134,8 +122,6 @@ extern int blocking_notifier_chain_unregister(struct blocking_notifier_head *nh, struct notifier_block *nb); extern int raw_notifier_chain_unregister(struct raw_notifier_head *nh, struct notifier_block *nb); -extern int srcu_notifier_chain_unregister(struct srcu_notifier_head *nh, - struct notifier_block *nb); extern int atomic_notifier_call_chain(struct atomic_notifier_head *nh, unsigned long val, void *v); @@ -149,10 +135,6 @@ extern int raw_notifier_call_chain(struct raw_notifier_head *nh, unsigned long val, void *v); extern int __raw_notifier_call_chain(struct raw_notifier_head *nh, unsigned long val, void *v, int nr_to_call, int *nr_calls); -extern int srcu_notifier_call_chain(struct srcu_notifier_head *nh, - unsigned long val, void *v); -extern int __srcu_notifier_call_chain(struct srcu_notifier_head *nh, - unsigned long val, void *v, int nr_to_call, int *nr_calls); #define NOTIFY_DONE 0x0000 /* Don't care */ #define NOTIFY_OK 0x0001 /* Suits me */ @@ -211,5 +193,30 @@ static inline int notifier_to_errno(int ret) extern struct blocking_notifier_head reboot_notifier_list; +#ifdef CONFIG_SRCU + +struct srcu_notifier_head { + struct mutex mutex; + struct srcu_struct srcu; + struct notifier_block __rcu *head; +}; + +/* srcu_notifier_heads must be initialized and cleaned up dynamically + * srcu_notifier_heads cannot be initialized statically + */ +extern void srcu_init_notifier_head(struct srcu_notifier_head *nh); +#define srcu_cleanup_notifier_head(name) cleanup_srcu_struct(&(name)->srcu) + +extern int srcu_notifier_chain_register(struct srcu_notifier_head *nh, + struct notifier_block *nb); +extern int srcu_notifier_chain_unregister(struct srcu_notifier_head *nh, + struct notifier_block *nb); +extern int srcu_notifier_call_chain(struct srcu_notifier_head *nh, + unsigned long val, void *v); +extern int __srcu_notifier_call_chain(struct srcu_notifier_head *nh, + unsigned long val, void *v, int nr_to_call, int *nr_calls); + +#endif /* CONFIG_SRCU */ + #endif /* __KERNEL__ */ #endif /* _LINUX_NOTIFIER_H */ diff --git a/include/linux/srcu.h b/include/linux/srcu.h index 9cfd962..ed9c389 100644 --- a/include/linux/srcu.h +++ b/include/linux/srcu.h @@ -26,6 +26,8 @@ * */ +#ifdef CONFIG_SRCU + #ifndef _LINUX_SRCU_H #define _LINUX_SRCU_H @@ -249,4 +251,6 @@ static inline void smp_mb__after_srcu_read_unlock(void) /* __srcu_read_unlock has smp_mb() internally so nothing to do here. */ } -#endif +#endif /* _LINUX_SRCU_H */ + +#endif /* CONFIG_SRCU */ -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/