68 lines
2.0 KiB
C++
68 lines
2.0 KiB
C++
/*
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* This file is open source software, licensed to you under the terms
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* of the Apache License, Version 2.0 (the "License"). See the NOTICE file
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* distributed with this work for additional information regarding copyright
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* ownership. You may not use this file except in compliance with the License.
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*
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing,
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* software distributed under the License is distributed on an
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* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
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* KIND, either express or implied. See the License for the
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* specific language governing permissions and limitations
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* under the License.
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*/
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#ifndef _XEN_GNTALLOC_HH
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#define _XEN_GNTALLOC_HH
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#include "core/posix.hh"
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namespace xen {
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class gntref {
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public:
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int xen_id;
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void* page;
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bool operator==(const gntref &a) { return (xen_id == a.xen_id) && (page == a.page); }
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gntref& operator=(const gntref &a) { xen_id = a.xen_id; page = a.page; return *this; }
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gntref(int id, void *page) : xen_id(id), page(page) {}
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gntref() : xen_id(-1), page(nullptr) {}
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operator bool() const { return xen_id != -1 && page != nullptr; }
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};
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class gntalloc;
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class grant_head {
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protected:
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unsigned _id = 0;
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public:
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virtual gntref new_ref() = 0;
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virtual gntref new_ref(void *addr, size_t size) = 0;
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virtual void free_ref(gntref& ref) = 0;
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};
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class gntalloc {
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protected:
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static gntalloc *_instance;
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unsigned _otherend;
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public:
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static gntalloc *instance(bool userspace, unsigned otherend);
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static gntalloc *instance();
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gntalloc(unsigned otherend) : _otherend(otherend) {}
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virtual gntref alloc_ref() = 0;
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// The kernel interface can defer allocation, userspace allocation
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// cannot. The boolean "alloc" tell us whether or not we should allocate
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// now or try to defer.
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virtual grant_head *alloc_ref(unsigned nr_ents) = 0;
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friend class grant_head;
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};
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extern gntref invalid_ref;
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}
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#endif
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