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linux-next/drivers/misc/cxl/base.c
Paul Gortmaker e00878be3f cxl: make base more explicitly non-modular
The Kconfig/Makefile currently controlling compilation of this code is:

drivers/misc/cxl/Kconfig:config CXL_BASE
drivers/misc/cxl/Kconfig:       bool

drivers/misc/cxl/Makefile:obj-$(CONFIG_CXL_BASE)          += base.o

...meaning that it currently is not being built as a module by anyone.

Lets convert the one module_init into device_initcall so that
when reading the driver it more clear that it is builtin-only.

Since module_init translates to device_initcall in the non-modular
case, the init ordering remains unchanged with this commit.

We don't replace module.h with init.h since the file is doing
other modular stuff (module_get/put) even though it is built-in.

Cc: Ian Munsie <imunsie@au1.ibm.com>
Cc: Michael Neuling <mikey@neuling.org>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-07-08 22:22:58 +10:00

118 lines
2.4 KiB
C

/*
* 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 <linux/module.h>
#include <linux/rcupdate.h>
#include <asm/errno.h>
#include <misc/cxl-base.h>
#include <linux/of_platform.h>
#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);
int cxl_update_properties(struct device_node *dn,
struct property *new_prop)
{
return of_update_property(dn, new_prop);
}
EXPORT_SYMBOL_GPL(cxl_update_properties);
static int __init cxl_base_init(void)
{
struct device_node *np = NULL;
struct platform_device *dev;
int count = 0;
/*
* Scan for compatible devices in guest only
*/
if (cpu_has_feature(CPU_FTR_HVMODE))
return 0;
while ((np = of_find_compatible_node(np, NULL,
"ibm,coherent-platform-facility"))) {
dev = of_platform_device_create(np, NULL, NULL);
if (dev)
count++;
}
pr_devel("Found %d cxl device(s)\n", count);
return 0;
}
device_initcall(cxl_base_init);