forked from Minki/linux
62ccf2d2ef
The Mellanox CX4 uses a model where the AFU is one physical function of the device, and is used by other peer physical functions of the same device. This will require those other devices to grab a reference on the AFU when they are initialised to make sure that it does not go away during their lifetime. Move the AFU refcount functions to base.c so they can be called from the PHB code. Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Reviewed-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
130 lines
2.7 KiB
C
130 lines
2.7 KiB
C
/*
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* Copyright 2014 IBM Corp.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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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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