126 lines
2.4 KiB
C
126 lines
2.4 KiB
C
|
// SPDX-License-Identifier: GPL-2.0-or-later
|
||
|
|
/*
|
||
|
|
* Copyright 2014 IBM Corp.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#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 */
|
||
|
|
|
||
|
|
/* AFU refcount management */
|
||
|
|
struct cxl_afu *cxl_afu_get(struct cxl_afu *afu)
|
||
|
|
{
|
||
|
|
return (get_device(&afu->dev) == NULL) ? NULL : afu;
|
||
|
|
}
|
||
|
|
EXPORT_SYMBOL_GPL(cxl_afu_get);
|
||
|
|
|
||
|
|
void cxl_afu_put(struct cxl_afu *afu)
|
||
|
|
{
|
||
|
|
put_device(&afu->dev);
|
||
|
|
}
|
||
|
|
EXPORT_SYMBOL_GPL(cxl_afu_put);
|
||
|
|
|
||
|
|
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;
|
||
|
|
struct platform_device *dev;
|
||
|
|
int count = 0;
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Scan for compatible devices in guest only
|
||
|
|
*/
|
||
|
|
if (cpu_has_feature(CPU_FTR_HVMODE))
|
||
|
|
return 0;
|
||
|
|
|
||
|
|
for_each_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);
|