1 #pragma once 2 3 /* 4 * Copyright (C) 2017 The Android Open Source Project 5 * 6 * Licensed under the Apache License, Version 2.0 (the "License"); 7 * you may not use this file except in compliance with the License. 8 * You may obtain a copy of the License at 9 * 10 * http://www.apache.org/licenses/LICENSE-2.0 11 * 12 * Unless required by applicable law or agreed to in writing, software 13 * distributed under the License is distributed on an "AS IS" BASIS, 14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 15 * See the License for the specific language governing permissions and 16 * limitations under the License. 17 */ 18 19 #include <sys/mman.h> 20 #include <stdint.h> 21 #include <memory> 22 #include "uapi/vsoc_shm.h" 23 24 namespace vsoc { 25 26 /** 27 * Base class for side-specific utility functions that work on regions. 28 * The methods in this class do not assume that the region is mapped in memory. 29 * This makes is appropriate for ManagedRegions and certain low-level tests 30 * of VSoC shared memory. Most other users will want to use TypedRegions with 31 * a defined RegionLayout. 32 * 33 * This class is not directly instantiable because it must be specialized with 34 * additional fields for the host and guest. 35 */ 36 class RegionControl { 37 public: 38 virtual ~RegionControl() { 39 if (region_base_) { 40 munmap(region_base_, region_size()); 41 } 42 region_base_ = nullptr; 43 } 44 45 #if defined(CUTTLEFISH_HOST) 46 static std::shared_ptr<RegionControl> Open(const char* region_name, 47 const char* domain); 48 #else 49 static std::shared_ptr<RegionControl> Open(const char* region_name); 50 #endif 51 52 const vsoc_device_region& region_desc() const { return region_desc_; } 53 54 // Returns the size of the entire region, including the signal tables. 55 uint32_t region_size() const { 56 return region_desc_.region_end_offset - region_desc_.region_begin_offset; 57 } 58 59 // Returns the size of the region that is usable for region-specific data. 60 uint32_t region_data_size() const { 61 return region_size() - region_desc_.offset_of_region_data; 62 } 63 64 // Creates a FdScopedPermission. Returns the file descriptor or -1 on 65 // failure. FdScopedPermission is not supported on the host, so -1 is 66 // always returned there. 67 virtual int CreateFdScopedPermission(const char* managed_region_name, 68 uint32_t owner_offset, 69 uint32_t owned_value, 70 uint32_t begin_offset, 71 uint32_t end_offset) = 0; 72 73 // Interrupt our peer, causing it to scan the outgoing_signal_table 74 virtual bool InterruptPeer() = 0; 75 76 // Wake the local signal table scanner. Primarily used during shutdown 77 virtual void InterruptSelf() = 0; 78 79 // Maps the entire region at an address, returning a pointer to the mapping 80 virtual void* Map() = 0; 81 82 // Wait for an interrupt from our peer 83 virtual void WaitForInterrupt() = 0; 84 85 // Signals local waiters at the given region offset. 86 // Defined only on the guest. 87 // Return value is negative on error. 88 virtual int SignalSelf(uint32_t offset) = 0; 89 90 // Waits for a signal at the given region offset. 91 // Defined only on the guest. 92 // Return value is negative on error. The number of false wakes is returned 93 // on success. 94 virtual int WaitForSignal(uint32_t offset, uint32_t expected_value) = 0; 95 96 template <typename T> 97 T* region_offset_to_pointer(uint32_t offset) { 98 if (offset > region_size()) { 99 LOG(FATAL) << __FUNCTION__ << ": " << offset << " not in region @" 100 << region_base_; 101 } 102 return reinterpret_cast<T*>(reinterpret_cast<uintptr_t>(region_base_) + 103 offset); 104 } 105 106 protected: 107 RegionControl() {} 108 void* region_base_{}; 109 vsoc_device_region region_desc_{}; 110 }; 111 } // namespace vsoc 112
