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#pragma once
/*
* Copyright (C) 2017 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <sys/mman.h>
#include <stdint.h>
#include <memory>
#include "uapi/vsoc_shm.h"
namespace vsoc {
/**
* Base class for side-specific utility functions that work on regions.
* The methods in this class do not assume that the region is mapped in memory.
* This makes is appropriate for ManagedRegions and certain low-level tests
* of VSoC shared memory. Most other users will want to use TypedRegions with
* a defined RegionLayout.
*
* This class is not directly instantiable because it must be specialized with
* additional fields for the host and guest.
*/
class RegionControl {
public:
virtual ~RegionControl() {
if (region_base_) {
munmap(region_base_, region_size());
}
region_base_ = nullptr;
}
#if defined(CUTTLEFISH_HOST)
static std::shared_ptr<RegionControl> Open(const char* region_name,
const char* domain);
#else
static std::shared_ptr<RegionControl> Open(const char* region_name);
#endif
const vsoc_device_region& region_desc() const { return region_desc_; }
// Returns the size of the entire region, including the signal tables.
uint32_t region_size() const {
return region_desc_.region_end_offset - region_desc_.region_begin_offset;
}
// Returns the size of the region that is usable for region-specific data.
uint32_t region_data_size() const {
return region_size() - region_desc_.offset_of_region_data;
}
// Creates a FdScopedPermission. Returns the file descriptor or -1 on
// failure. FdScopedPermission is not supported on the host, so -1 is
// always returned there.
virtual int CreateFdScopedPermission(const char* managed_region_name,
uint32_t owner_offset,
uint32_t owned_value,
uint32_t begin_offset,
uint32_t end_offset) = 0;
// Interrupt our peer, causing it to scan the outgoing_signal_table
virtual bool InterruptPeer() = 0;
// Wake the local signal table scanner. Primarily used during shutdown
virtual void InterruptSelf() = 0;
// Maps the entire region at an address, returning a pointer to the mapping
virtual void* Map() = 0;
// Wait for an interrupt from our peer
virtual void WaitForInterrupt() = 0;
// Signals local waiters at the given region offset.
// Defined only on the guest.
// Return value is negative on error.
virtual int SignalSelf(uint32_t offset) = 0;
// Waits for a signal at the given region offset.
// Defined only on the guest.
// Return value is negative on error. The number of false wakes is returned
// on success.
virtual int WaitForSignal(uint32_t offset, uint32_t expected_value) = 0;
template <typename T>
T* region_offset_to_pointer(uint32_t offset) {
if (offset > region_size()) {
LOG(FATAL) << __FUNCTION__ << ": " << offset << " not in region @"
<< region_base_;
}
return reinterpret_cast<T*>(reinterpret_cast<uintptr_t>(region_base_) +
offset);
}
protected:
RegionControl() {}
void* region_base_{};
vsoc_device_region region_desc_{};
};
} // namespace vsoc
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