kernel/dev/iommu/intel/iommu_page.h

// Copyright 2018 The Fuchsia Authors
//
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file or at
// https://opensource.org/licenses/MIT

#pragma once

#include <err.h>
#include <fbl/macros.h>
#include <stdint.h>
#include <vm/pmm.h>

namespace intel_iommu {

static constexpr paddr_t kInvalidPaddr = UINT64_MAX;

// RAII object for managing the lifetime of the memory that backs hardware
// datastructures.
class IommuPage {
public:
    IommuPage()
        : page_(nullptr), virt_(0) {}
    ~IommuPage();

    IommuPage(IommuPage&& p)
        : page_(p.page_), virt_(p.virt_) {
        p.page_ = nullptr;
        p.virt_ = 0;
    }
    IommuPage& operator=(IommuPage&& p) {
        page_ = p.page_;
        virt_ = p.virt_;
        p.page_ = nullptr;
        p.virt_ = 0;
        return *this;
    }

    static zx_status_t AllocatePage(IommuPage* out);

    uintptr_t vaddr() const {
        return virt_;
    }
    paddr_t paddr() const {
        return likely(page_) ? page_->paddr() : kInvalidPaddr;
    }

private:
    IommuPage(vm_page_t* page, uintptr_t virt);
    DISALLOW_COPY_AND_ASSIGN_ALLOW_MOVE(IommuPage);

    vm_page_t* page_;
    uintptr_t virt_;
};

} // namespace intel_iommu