Cody Schuffelen | 134ff03 | 2019-11-22 00:25:32 -0800 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright (C) 2017 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | #include "guest/vsoc/lib/gralloc_region_view.h" |
| 18 | |
| 19 | #include <common/vsoc/lib/lock_guard.h> |
| 20 | #include <log/log.h> |
| 21 | #include <sys/types.h> |
| 22 | #include <uapi/vsoc_shm.h> |
| 23 | #include <atomic> |
| 24 | |
| 25 | using vsoc::gralloc::GrallocRegionView; |
| 26 | using vsoc::layout::gralloc::BufferEntry; |
| 27 | using vsoc::layout::gralloc::GrallocBufferLayout; |
| 28 | using vsoc::layout::gralloc::GrallocManagerLayout; |
| 29 | |
| 30 | namespace { |
| 31 | template <typename T> |
| 32 | inline T gralloc_align(T val) { |
| 33 | return (val + PAGE_SIZE - 1) & ~(PAGE_SIZE - 1); |
| 34 | } |
| 35 | |
| 36 | // Use the thread id to identify the original creator of a buffer. |
| 37 | inline uint32_t gralloc_owned_value() { |
| 38 | return gettid(); |
| 39 | } |
| 40 | |
| 41 | } // namespace |
| 42 | |
| 43 | bool GrallocRegionView::Open() { |
| 44 | if (!vsoc::ManagerRegionView<GrallocRegionView, GrallocManagerLayout>::Open()) { |
| 45 | return false; |
| 46 | } |
| 47 | std::shared_ptr<vsoc::RegionControl> managed_region = |
| 48 | vsoc::RegionControl::Open( |
| 49 | GrallocManagerLayout::ManagedRegion::region_name); |
| 50 | if (!managed_region) { |
| 51 | LOG_FATAL("Unable to open managed region"); |
| 52 | return false; |
| 53 | } |
| 54 | offset_of_buffer_memory_ = gralloc_align<uint32_t>( |
| 55 | managed_region->region_desc().offset_of_region_data); |
| 56 | total_buffer_memory_ = |
| 57 | managed_region->region_size() - offset_of_buffer_memory_; |
| 58 | |
| 59 | // TODO(jemoreira): Handle the case of unexpected values in the region. |
| 60 | return true; |
| 61 | } |
| 62 | |
| 63 | int GrallocRegionView::AllocateBuffer(size_t size, uint32_t* begin_offset) { |
| 64 | size = gralloc_align<size_t>(size); |
| 65 | // Cache the value of buffer_count in shared memory. |
| 66 | uint32_t buffer_count_local = 0; |
| 67 | { |
| 68 | vsoc::LockGuard<vsoc::layout::GuestLock>(&data()->new_buffer_lock); |
| 69 | buffer_count_local = data()->buffer_count; |
| 70 | } |
| 71 | // Find a free buffer entry of the appropriate size. |
| 72 | for (uint32_t idx = 0; idx < buffer_count_local; ++idx) { |
| 73 | BufferEntry& entry = data()->buffers_table[idx]; |
| 74 | if (entry.owned_by == VSOC_REGION_FREE && entry.buffer_size() == size) { |
| 75 | int fd = control_->CreateFdScopedPermission( |
| 76 | GrallocManagerLayout::ManagedRegion::region_name, |
| 77 | pointer_to_region_offset(&entry.owned_by), |
| 78 | gralloc_owned_value(), |
| 79 | entry.buffer_begin, |
| 80 | entry.buffer_end); |
| 81 | if (fd >= 0) { |
| 82 | if (begin_offset) { |
| 83 | *begin_offset = entry.buffer_begin; |
| 84 | } |
| 85 | return fd; |
| 86 | } |
| 87 | } |
| 88 | } |
| 89 | |
| 90 | // We couldn't find any suitable buffer, create one |
| 91 | { |
| 92 | vsoc::LockGuard<vsoc::layout::GuestLock>(&data()->new_buffer_lock); |
| 93 | // don't use the cached value here!!! |
| 94 | uint32_t idx = data()->buffer_count; |
| 95 | if (pointer_to_region_offset(&data()->buffers_table[idx + 1]) > |
| 96 | control_->region_size()) { |
| 97 | ALOGE( |
| 98 | "Out of memory in gralloc_manager (total: %d, used: %d, " |
| 99 | "requested: %d)", |
| 100 | static_cast<int>(control_->region_size()), |
| 101 | static_cast<int>( |
| 102 | pointer_to_region_offset(&data()->buffers_table[idx])), |
| 103 | static_cast<int>(sizeof(data()->buffers_table[idx]))); |
| 104 | return -ENOMEM; |
| 105 | } |
| 106 | if (total_buffer_memory_ - data()->allocated_buffer_memory < size) { |
| 107 | ALOGE( |
| 108 | "Out of memory in gralloc_memory (total: %d, used: %d, requested: %d)", |
| 109 | static_cast<int>(total_buffer_memory_), |
| 110 | static_cast<int>(data()->allocated_buffer_memory), |
| 111 | static_cast<int>(size)); |
| 112 | return -ENOMEM; |
| 113 | } |
| 114 | // Initialize the buffer entry and acquire ownership |
| 115 | // Do it before increasing buffer_count so that another thread looking for |
| 116 | // free entries doesn't find this one |
| 117 | BufferEntry& new_entry = data()->buffers_table[idx]; |
| 118 | new_entry.buffer_begin = |
| 119 | offset_of_buffer_memory_ + data()->allocated_buffer_memory; |
| 120 | data()->allocated_buffer_memory += size; |
| 121 | new_entry.buffer_end = new_entry.buffer_begin + size; |
| 122 | int fd = control_->CreateFdScopedPermission( |
| 123 | GrallocManagerLayout::ManagedRegion::region_name, |
| 124 | pointer_to_region_offset(&new_entry.owned_by), |
| 125 | gralloc_owned_value(), |
| 126 | new_entry.buffer_begin, |
| 127 | new_entry.buffer_end); |
| 128 | if (fd < 0) { |
| 129 | LOG_FATAL( |
| 130 | "Unexpected error while creating fd scoped permission over " |
| 131 | "uncontested memory: %s", |
| 132 | strerror(-fd)); |
| 133 | return fd; |
| 134 | } |
| 135 | // Increment buffer_count now that the entry can't be taken from us |
| 136 | data()->buffer_count++; |
| 137 | if (begin_offset) { |
| 138 | *begin_offset = new_entry.buffer_begin; |
| 139 | } |
| 140 | return fd; |
| 141 | } |
| 142 | } |