// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Copyright 2014 IBM Corp.
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*/
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#include <linux/module.h>
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#include <linux/rcupdate.h>
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#include <asm/errno.h>
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#include <misc/cxl-base.h>
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#include <linux/of_platform.h>
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#include "cxl.h"
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/* protected by rcu */
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static struct cxl_calls *cxl_calls;
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atomic_t cxl_use_count = ATOMIC_INIT(0);
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EXPORT_SYMBOL(cxl_use_count);
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#ifdef CONFIG_CXL_MODULE
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static inline struct cxl_calls *cxl_calls_get(void)
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{
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struct cxl_calls *calls = NULL;
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rcu_read_lock();
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calls = rcu_dereference(cxl_calls);
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if (calls && !try_module_get(calls->owner))
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calls = NULL;
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rcu_read_unlock();
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return calls;
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}
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static inline void cxl_calls_put(struct cxl_calls *calls)
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{
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BUG_ON(calls != cxl_calls);
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/* we don't need to rcu this, as we hold a reference to the module */
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module_put(cxl_calls->owner);
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}
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#else /* !defined CONFIG_CXL_MODULE */
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static inline struct cxl_calls *cxl_calls_get(void)
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{
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return cxl_calls;
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}
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static inline void cxl_calls_put(struct cxl_calls *calls) { }
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#endif /* CONFIG_CXL_MODULE */
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/* AFU refcount management */
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struct cxl_afu *cxl_afu_get(struct cxl_afu *afu)
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{
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return (get_device(&afu->dev) == NULL) ? NULL : afu;
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}
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EXPORT_SYMBOL_GPL(cxl_afu_get);
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void cxl_afu_put(struct cxl_afu *afu)
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{
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put_device(&afu->dev);
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}
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EXPORT_SYMBOL_GPL(cxl_afu_put);
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void cxl_slbia(struct mm_struct *mm)
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{
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struct cxl_calls *calls;
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calls = cxl_calls_get();
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if (!calls)
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return;
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if (cxl_ctx_in_use())
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calls->cxl_slbia(mm);
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cxl_calls_put(calls);
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}
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int register_cxl_calls(struct cxl_calls *calls)
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{
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if (cxl_calls)
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return -EBUSY;
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rcu_assign_pointer(cxl_calls, calls);
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return 0;
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}
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EXPORT_SYMBOL_GPL(register_cxl_calls);
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void unregister_cxl_calls(struct cxl_calls *calls)
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{
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BUG_ON(cxl_calls->owner != calls->owner);
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RCU_INIT_POINTER(cxl_calls, NULL);
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synchronize_rcu();
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}
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EXPORT_SYMBOL_GPL(unregister_cxl_calls);
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int cxl_update_properties(struct device_node *dn,
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struct property *new_prop)
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{
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return of_update_property(dn, new_prop);
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}
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EXPORT_SYMBOL_GPL(cxl_update_properties);
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static int __init cxl_base_init(void)
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{
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struct device_node *np;
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struct platform_device *dev;
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int count = 0;
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/*
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* Scan for compatible devices in guest only
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*/
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if (cpu_has_feature(CPU_FTR_HVMODE))
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return 0;
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for_each_compatible_node(np, NULL, "ibm,coherent-platform-facility") {
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dev = of_platform_device_create(np, NULL, NULL);
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if (dev)
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count++;
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}
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pr_devel("Found %d cxl device(s)\n", count);
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return 0;
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}
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device_initcall(cxl_base_init);
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