From 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 Mon Sep 17 00:00:00 2001 From: Yunhong Jiang Date: Tue, 4 Aug 2015 12:17:53 -0700 Subject: Add the rt linux 4.1.3-rt3 as base Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang --- kernel/drivers/misc/cxl/base.c | 86 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 86 insertions(+) create mode 100644 kernel/drivers/misc/cxl/base.c (limited to 'kernel/drivers/misc/cxl/base.c') diff --git a/kernel/drivers/misc/cxl/base.c b/kernel/drivers/misc/cxl/base.c new file mode 100644 index 000000000..0654ad836 --- /dev/null +++ b/kernel/drivers/misc/cxl/base.c @@ -0,0 +1,86 @@ +/* + * Copyright 2014 IBM Corp. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#include +#include +#include +#include +#include "cxl.h" + +/* protected by rcu */ +static struct cxl_calls *cxl_calls; + +atomic_t cxl_use_count = ATOMIC_INIT(0); +EXPORT_SYMBOL(cxl_use_count); + +#ifdef CONFIG_CXL_MODULE + +static inline struct cxl_calls *cxl_calls_get(void) +{ + struct cxl_calls *calls = NULL; + + rcu_read_lock(); + calls = rcu_dereference(cxl_calls); + if (calls && !try_module_get(calls->owner)) + calls = NULL; + rcu_read_unlock(); + + return calls; +} + +static inline void cxl_calls_put(struct cxl_calls *calls) +{ + BUG_ON(calls != cxl_calls); + + /* we don't need to rcu this, as we hold a reference to the module */ + module_put(cxl_calls->owner); +} + +#else /* !defined CONFIG_CXL_MODULE */ + +static inline struct cxl_calls *cxl_calls_get(void) +{ + return cxl_calls; +} + +static inline void cxl_calls_put(struct cxl_calls *calls) { } + +#endif /* CONFIG_CXL_MODULE */ + +void cxl_slbia(struct mm_struct *mm) +{ + struct cxl_calls *calls; + + calls = cxl_calls_get(); + if (!calls) + return; + + if (cxl_ctx_in_use()) + calls->cxl_slbia(mm); + + cxl_calls_put(calls); +} + +int register_cxl_calls(struct cxl_calls *calls) +{ + if (cxl_calls) + return -EBUSY; + + rcu_assign_pointer(cxl_calls, calls); + return 0; +} +EXPORT_SYMBOL_GPL(register_cxl_calls); + +void unregister_cxl_calls(struct cxl_calls *calls) +{ + BUG_ON(cxl_calls->owner != calls->owner); + RCU_INIT_POINTER(cxl_calls, NULL); + synchronize_rcu(); +} +EXPORT_SYMBOL_GPL(unregister_cxl_calls); -- cgit 1.2.3-korg