media/codec2/vndk/C2DmaBufAllocator.cpp - platform/frameworks/av - Git at Google

 /*
  * Copyright (C) 2020 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.
  */

 //#define LOG_NDEBUG 0
 #define LOG_TAG "C2DmaBufAllocator"

 #include <BufferAllocator/BufferAllocator.h>
 #include <C2Buffer.h>
 #include <C2Debug.h>
 #include <C2DmaBufAllocator.h>
 #include <C2ErrnoUtils.h>

 #include <linux/ion.h>
 #include <sys/mman.h>
 #include <unistd.h>  // getpagesize, size_t, close, dup
 #include <utils/Log.h>

 #include <list>

 #include <android-base/properties.h>
 #include <media/stagefright/foundation/Mutexed.h>

 namespace android {

 namespace {
     constexpr size_t USAGE_LRU_CACHE_SIZE = 1024;

     // max padding after ion/dmabuf allocations in bytes
     constexpr uint32_t MAX_PADDING = 0x8000; // 32KB
 }

 /* =========================== BUFFER HANDLE =========================== */
 /**
  * Buffer handle
  *
  * Stores dmabuf fd & metadata
  *
  * This handle will not capture mapped fd-s as updating that would require a
  * global mutex.
  */

 struct C2HandleBuf : public C2Handle {
     C2HandleBuf(int bufferFd, size_t size)
         : C2Handle(cHeader),
           mFds{bufferFd},
           mInts{int(size & 0xFFFFFFFF), int((uint64_t(size) >> 32) & 0xFFFFFFFF), kMagic} {}

     static bool IsValid(const C2Handle* const o);

     int bufferFd() const { return mFds.mBuffer; }
     size_t size() const {
         return size_t(unsigned(mInts.mSizeLo)) | size_t(uint64_t(unsigned(mInts.mSizeHi)) << 32);
     }

    protected:
     struct {
         int mBuffer;  // dmabuf fd
     } mFds;
     struct {
         int mSizeLo;  // low 32-bits of size
         int mSizeHi;  // high 32-bits of size
         int mMagic;
     } mInts;

    private:
     typedef C2HandleBuf _type;
     enum {
         kMagic = '\xc2io\x00',
         numFds = sizeof(mFds) / sizeof(int),
         numInts = sizeof(mInts) / sizeof(int),
         version = sizeof(C2Handle)
     };
     // constexpr static C2Handle cHeader = { version, numFds, numInts, {} };
     const static C2Handle cHeader;
 };

 const C2Handle C2HandleBuf::cHeader = {
         C2HandleBuf::version, C2HandleBuf::numFds, C2HandleBuf::numInts, {}};

 // static
 bool C2HandleBuf::IsValid(const C2Handle* const o) {
     if (!o || memcmp(o, &cHeader, sizeof(cHeader))) {
         return false;
     }
     const C2HandleBuf* other = static_cast<const C2HandleBuf*>(o);
     return other->mInts.mMagic == kMagic;
 }

 /* =========================== DMABUF ALLOCATION =========================== */
 class C2DmaBufAllocation : public C2LinearAllocation {
    public:
     /* Interface methods */
     virtual c2_status_t map(size_t offset, size_t size, C2MemoryUsage usage, C2Fence* fence,
                             void** addr /* nonnull */) override;
     virtual c2_status_t unmap(void* addr, size_t size, C2Fence* fenceFd) override;
     virtual ~C2DmaBufAllocation() override;
     virtual const C2Handle* handle() const override;
     virtual id_t getAllocatorId() const override;
     virtual bool equals(const std::shared_ptr<C2LinearAllocation>& other) const override;

     // internal methods

     /**
       * Constructs an allocation via a new allocation.
       *
       * @param alloc     allocator
       * @param allocSize size used for the allocator
       * @param capacity  capacity advertised to the client
       * @param heap_name name of the dmabuf heap (device)
       * @param flags     flags
       * @param id        allocator id
       */
     C2DmaBufAllocation(BufferAllocator& alloc, size_t allocSize, size_t capacity,
                        C2String heap_name, unsigned flags, C2Allocator::id_t id);

     /**
       * Constructs an allocation by wrapping an existing allocation.
       *
       * @param size    capacity advertised to the client
       * @param shareFd dmabuf fd of the wrapped allocation
       * @param id      allocator id
       */
     C2DmaBufAllocation(size_t size, int shareFd, C2Allocator::id_t id);

     c2_status_t status() const;

    protected:
     virtual c2_status_t mapInternal(size_t mapSize, size_t mapOffset, size_t alignmentBytes,
                                     int prot, int flags, void** base, void** addr) {
         c2_status_t err = C2_OK;
         *base = mmap(nullptr, mapSize, prot, flags, mHandle.bufferFd(), mapOffset);
         ALOGV("mmap(size = %zu, prot = %d, flags = %d, mapFd = %d, offset = %zu) "
               "returned (%d)",
               mapSize, prot, flags, mHandle.bufferFd(), mapOffset, errno);
         if (*base == MAP_FAILED) {
             *base = *addr = nullptr;
             err = c2_map_errno<EINVAL>(errno);
         } else {
             *addr = (uint8_t*)*base + alignmentBytes;
         }
         return err;
     }

     C2Allocator::id_t mId;
     C2HandleBuf mHandle;
     c2_status_t mInit;
     struct Mapping {
         void* addr;
         size_t alignmentBytes;
         size_t size;
     };
     Mutexed<std::list<Mapping>> mMappings;

     // TODO: we could make this encapsulate shared_ptr and copiable
     C2_DO_NOT_COPY(C2DmaBufAllocation);
 };

 c2_status_t C2DmaBufAllocation::map(size_t offset, size_t size, C2MemoryUsage usage, C2Fence* fence,
                                     void** addr) {
     (void)fence;  // TODO: wait for fence
     *addr = nullptr;
     if (!mMappings.lock()->empty()) {
         ALOGV("multiple map");
         // TODO: technically we should return DUPLICATE here, but our block views
         // don't actually unmap, so we end up remapping the buffer multiple times.
         //
         // return C2_DUPLICATE;
     }
     if (size == 0) {
         return C2_BAD_VALUE;
     }

     int prot = PROT_NONE;
     int flags = MAP_SHARED;
     if (usage.expected & C2MemoryUsage::CPU_READ) {
         prot |= PROT_READ;
     }
     if (usage.expected & C2MemoryUsage::CPU_WRITE) {
         prot |= PROT_WRITE;
     }

     size_t alignmentBytes = offset % PAGE_SIZE;
     size_t mapOffset = offset - alignmentBytes;
     size_t mapSize = size + alignmentBytes;
     Mapping map = {nullptr, alignmentBytes, mapSize};

     c2_status_t err =
             mapInternal(mapSize, mapOffset, alignmentBytes, prot, flags, &(map.addr), addr);
     if (map.addr) {
         mMappings.lock()->push_back(map);
     }
     return err;
 }

 c2_status_t C2DmaBufAllocation::unmap(void* addr, size_t size, C2Fence* fence) {
     Mutexed<std::list<Mapping>>::Locked mappings(mMappings);
     if (mappings->empty()) {
         ALOGD("tried to unmap unmapped buffer");
         return C2_NOT_FOUND;
     }
     for (auto it = mappings->begin(); it != mappings->end(); ++it) {
         if (addr != (uint8_t*)it->addr + it->alignmentBytes ||
             size + it->alignmentBytes != it->size) {
             continue;
         }
         int err = munmap(it->addr, it->size);
         if (err != 0) {
             ALOGD("munmap failed");
             return c2_map_errno<EINVAL>(errno);
         }
         if (fence) {
             *fence = C2Fence();  // not using fences
         }
         (void)mappings->erase(it);
         ALOGV("successfully unmapped: %d", mHandle.bufferFd());
         return C2_OK;
     }
     ALOGD("unmap failed to find specified map");
     return C2_BAD_VALUE;
 }

 c2_status_t C2DmaBufAllocation::status() const {
     return mInit;
 }

 C2Allocator::id_t C2DmaBufAllocation::getAllocatorId() const {
     return mId;
 }

 bool C2DmaBufAllocation::equals(const std::shared_ptr<C2LinearAllocation>& other) const {
     if (!other || other->getAllocatorId() != getAllocatorId()) {
         return false;
     }
     // get user handle to compare objects
     std::shared_ptr<C2DmaBufAllocation> otherAsBuf =
             std::static_pointer_cast<C2DmaBufAllocation>(other);
     return mHandle.bufferFd() == otherAsBuf->mHandle.bufferFd();
 }

 const C2Handle* C2DmaBufAllocation::handle() const {
     return &mHandle;
 }

 C2DmaBufAllocation::~C2DmaBufAllocation() {
     Mutexed<std::list<Mapping>>::Locked mappings(mMappings);
     if (!mappings->empty()) {
         ALOGD("Dangling mappings!");
         for (const Mapping& map : *mappings) {
             int err = munmap(map.addr, map.size);
             if (err) ALOGD("munmap failed");
         }
     }
     if (mInit == C2_OK) {
         native_handle_close(&mHandle);
     }
 }

 C2DmaBufAllocation::C2DmaBufAllocation(BufferAllocator& alloc, size_t allocSize, size_t capacity,
                                        C2String heap_name, unsigned flags, C2Allocator::id_t id)
     : C2LinearAllocation(capacity), mHandle(-1, 0) {
     int bufferFd = -1;
     int ret = 0;

     bufferFd = alloc.Alloc(heap_name, allocSize, flags);
     if (bufferFd < 0) {
         ret = bufferFd;
     }

     // this may be a non-working handle if bufferFd is negative
     mHandle = C2HandleBuf(bufferFd, capacity);
     mId = id;
     mInit = c2_status_t(c2_map_errno<ENOMEM, EACCES, EINVAL>(ret));
 }

 C2DmaBufAllocation::C2DmaBufAllocation(size_t size, int shareFd, C2Allocator::id_t id)
     : C2LinearAllocation(size), mHandle(-1, 0) {
     mHandle = C2HandleBuf(shareFd, size);
     mId = id;
     mInit = c2_status_t(c2_map_errno<ENOMEM, EACCES, EINVAL>(0));
 }

 /* =========================== DMABUF ALLOCATOR =========================== */
 C2DmaBufAllocator::C2DmaBufAllocator(id_t id) : mInit(C2_OK) {
     C2MemoryUsage minUsage = {0, 0};
     C2MemoryUsage maxUsage = {C2MemoryUsage::CPU_READ, C2MemoryUsage::CPU_WRITE};
     Traits traits = {"android.allocator.dmabuf", id, LINEAR, minUsage, maxUsage};
     mTraits = std::make_shared<Traits>(traits);
 }

 C2Allocator::id_t C2DmaBufAllocator::getId() const {
     std::lock_guard<std::mutex> lock(mUsageMapperLock);
     return mTraits->id;
 }

 C2String C2DmaBufAllocator::getName() const {
     std::lock_guard<std::mutex> lock(mUsageMapperLock);
     return mTraits->name;
 }

 std::shared_ptr<const C2Allocator::Traits> C2DmaBufAllocator::getTraits() const {
     std::lock_guard<std::mutex> lock(mUsageMapperLock);
     return mTraits;
 }

 void C2DmaBufAllocator::setUsageMapper(const UsageMapperFn& mapper __unused, uint64_t minUsage,
                                        uint64_t maxUsage, uint64_t blockSize) {
     std::lock_guard<std::mutex> lock(mUsageMapperLock);
     mUsageMapperCache.clear();
     mUsageMapperLru.clear();
     mUsageMapper = mapper;
     Traits traits = {mTraits->name, mTraits->id, LINEAR, C2MemoryUsage(minUsage),
                      C2MemoryUsage(maxUsage)};
     mTraits = std::make_shared<Traits>(traits);
     mBlockSize = blockSize;
 }

 std::size_t C2DmaBufAllocator::MapperKeyHash::operator()(const MapperKey& k) const {
     return std::hash<uint64_t>{}(k.first) ^ std::hash<size_t>{}(k.second);
 }

 c2_status_t C2DmaBufAllocator::mapUsage(C2MemoryUsage usage, size_t capacity, C2String* heap_name,
                                         unsigned* flags) {
     std::lock_guard<std::mutex> lock(mUsageMapperLock);
     c2_status_t res = C2_OK;
     // align capacity
     capacity = (capacity + mBlockSize - 1) & ~(mBlockSize - 1);
     MapperKey key = std::make_pair(usage.expected, capacity);
     auto entry = mUsageMapperCache.find(key);
     if (entry == mUsageMapperCache.end()) {
         if (mUsageMapper) {
             res = mUsageMapper(usage, capacity, heap_name, flags);
         } else {
             if (C2DmaBufAllocator::system_uncached_supported() &&
                 !(usage.expected & (C2MemoryUsage::CPU_READ | C2MemoryUsage::CPU_WRITE)))
                 *heap_name = "system-uncached";
             else
                 *heap_name = "system";
             *flags = 0;
             res = C2_NO_INIT;
         }
         // add usage to cache
         MapperValue value = std::make_tuple(*heap_name, *flags, res);
         mUsageMapperLru.emplace_front(key, value);
         mUsageMapperCache.emplace(std::make_pair(key, mUsageMapperLru.begin()));
         if (mUsageMapperCache.size() > USAGE_LRU_CACHE_SIZE) {
             // remove LRU entry
             MapperKey lruKey = mUsageMapperLru.front().first;
             mUsageMapperCache.erase(lruKey);
             mUsageMapperLru.pop_back();
         }
     } else {
         // move entry to MRU
         mUsageMapperLru.splice(mUsageMapperLru.begin(), mUsageMapperLru, entry->second);
         const MapperValue& value = entry->second->second;
         std::tie(*heap_name, *flags, res) = value;
     }
     return res;
 }

 c2_status_t C2DmaBufAllocator::newLinearAllocation(
         uint32_t capacity, C2MemoryUsage usage, std::shared_ptr<C2LinearAllocation>* allocation) {
     if (allocation == nullptr) {
         return C2_BAD_VALUE;
     }

     allocation->reset();
     if (mInit != C2_OK) {
         return mInit;
     }

     C2String heap_name;
     unsigned flags = 0;
     c2_status_t ret = mapUsage(usage, capacity, &heap_name, &flags);
     if (ret && ret != C2_NO_INIT) {
         return ret;
     }

     // TODO: should we pad before mapping usage?

     // NOTE: read this property directly from the property as this code has to run on
     // Android Q, but the sysprop was only introduced in Android S.
     static size_t sPadding =
         base::GetUintProperty("media.c2.dmabuf.padding", (uint32_t)0, MAX_PADDING);
     if (sPadding > SIZE_MAX - capacity) {
         // size would overflow
         ALOGD("dmabuf_alloc: size #%x cannot accommodate padding #%zx", capacity, sPadding);
         return C2_NO_MEMORY;
     }

     size_t allocSize = (size_t)capacity + sPadding;
     // TODO: should we align allocation size to mBlockSize to reflect the true allocation size?
     std::shared_ptr<C2DmaBufAllocation> alloc = std::make_shared<C2DmaBufAllocation>(
             mBufferAllocator, allocSize, allocSize - sPadding, heap_name, flags, getId());
     ret = alloc->status();
     if (ret == C2_OK) {
         *allocation = alloc;
     }
     return ret;
 }

 c2_status_t C2DmaBufAllocator::priorLinearAllocation(
         const C2Handle* handle, std::shared_ptr<C2LinearAllocation>* allocation) {
     *allocation = nullptr;
     if (mInit != C2_OK) {
         return mInit;
     }

     if (!C2HandleBuf::IsValid(handle)) {
         return C2_BAD_VALUE;
     }

     // TODO: get capacity and validate it
     const C2HandleBuf* h = static_cast<const C2HandleBuf*>(handle);
     std::shared_ptr<C2DmaBufAllocation> alloc =
             std::make_shared<C2DmaBufAllocation>(h->size(), h->bufferFd(), getId());
     c2_status_t ret = alloc->status();
     if (ret == C2_OK) {
         *allocation = alloc;
         native_handle_delete(
                 const_cast<native_handle_t*>(reinterpret_cast<const native_handle_t*>(handle)));
     }
     return ret;
 }

 // static
 bool C2DmaBufAllocator::CheckHandle(const C2Handle* const o) {
     return C2HandleBuf::IsValid(o);
 }

 }  // namespace android
	/*
	* Copyright (C) 2020 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.
	*/

	//#define LOG_NDEBUG 0
	#define LOG_TAG "C2DmaBufAllocator"

	#include <BufferAllocator/BufferAllocator.h>
	#include <C2Buffer.h>
	#include <C2Debug.h>
	#include <C2DmaBufAllocator.h>
	#include <C2ErrnoUtils.h>

	#include <linux/ion.h>
	#include <sys/mman.h>
	#include <unistd.h> // getpagesize, size_t, close, dup
	#include <utils/Log.h>

	#include <list>

	#include <android-base/properties.h>
	#include <media/stagefright/foundation/Mutexed.h>

	namespace android {

	namespace {
	constexpr size_t USAGE_LRU_CACHE_SIZE = 1024;

	// max padding after ion/dmabuf allocations in bytes
	constexpr uint32_t MAX_PADDING = 0x8000; // 32KB
	}

	/* =========================== BUFFER HANDLE =========================== */
	/**
	* Buffer handle
	*
	* Stores dmabuf fd & metadata
	*
	* This handle will not capture mapped fd-s as updating that would require a
	* global mutex.
	*/

	struct C2HandleBuf : public C2Handle {
	C2HandleBuf(int bufferFd, size_t size)
	: C2Handle(cHeader),
	mFds{bufferFd},
	mInts{int(size & 0xFFFFFFFF), int((uint64_t(size) >> 32) & 0xFFFFFFFF), kMagic} {}

	static bool IsValid(const C2Handle* const o);

	int bufferFd() const { return mFds.mBuffer; }
	size_t size() const {
	return size_t(unsigned(mInts.mSizeLo)) \| size_t(uint64_t(unsigned(mInts.mSizeHi)) << 32);
	}

	protected:
	struct {
	int mBuffer; // dmabuf fd
	} mFds;
	struct {
	int mSizeLo; // low 32-bits of size
	int mSizeHi; // high 32-bits of size
	int mMagic;
	} mInts;

	private:
	typedef C2HandleBuf _type;
	enum {
	kMagic = '\xc2io\x00',
	numFds = sizeof(mFds) / sizeof(int),
	numInts = sizeof(mInts) / sizeof(int),
	version = sizeof(C2Handle)
	};
	// constexpr static C2Handle cHeader = { version, numFds, numInts, {} };
	const static C2Handle cHeader;
	};

	const C2Handle C2HandleBuf::cHeader = {
	C2HandleBuf::version, C2HandleBuf::numFds, C2HandleBuf::numInts, {}};

	// static
	bool C2HandleBuf::IsValid(const C2Handle* const o) {
	if (!o \|\| memcmp(o, &cHeader, sizeof(cHeader))) {
	return false;
	}
	const C2HandleBuf* other = static_cast<const C2HandleBuf*>(o);
	return other->mInts.mMagic == kMagic;
	}

	/* =========================== DMABUF ALLOCATION =========================== */
	class C2DmaBufAllocation : public C2LinearAllocation {
	public:
	/* Interface methods */
	virtual c2_status_t map(size_t offset, size_t size, C2MemoryUsage usage, C2Fence* fence,
	void** addr /* nonnull */) override;
	virtual c2_status_t unmap(void* addr, size_t size, C2Fence* fenceFd) override;
	virtual ~C2DmaBufAllocation() override;
	virtual const C2Handle* handle() const override;
	virtual id_t getAllocatorId() const override;
	virtual bool equals(const std::shared_ptr<C2LinearAllocation>& other) const override;

	// internal methods

	/**
	* Constructs an allocation via a new allocation.
	*
	* @param alloc allocator
	* @param allocSize size used for the allocator
	* @param capacity capacity advertised to the client
	* @param heap_name name of the dmabuf heap (device)
	* @param flags flags
	* @param id allocator id
	*/
	C2DmaBufAllocation(BufferAllocator& alloc, size_t allocSize, size_t capacity,
	C2String heap_name, unsigned flags, C2Allocator::id_t id);

	/**
	* Constructs an allocation by wrapping an existing allocation.
	*
	* @param size capacity advertised to the client
	* @param shareFd dmabuf fd of the wrapped allocation
	* @param id allocator id
	*/
	C2DmaBufAllocation(size_t size, int shareFd, C2Allocator::id_t id);

	c2_status_t status() const;

	protected:
	virtual c2_status_t mapInternal(size_t mapSize, size_t mapOffset, size_t alignmentBytes,
	int prot, int flags, void base, void addr) {
	c2_status_t err = C2_OK;
	*base = mmap(nullptr, mapSize, prot, flags, mHandle.bufferFd(), mapOffset);
	ALOGV("mmap(size = %zu, prot = %d, flags = %d, mapFd = %d, offset = %zu) "
	"returned (%d)",
	mapSize, prot, flags, mHandle.bufferFd(), mapOffset, errno);
	if (*base == MAP_FAILED) {
	base = addr = nullptr;
	err = c2_map_errno<EINVAL>(errno);
	} else {
	addr = (uint8_t)*base + alignmentBytes;
	}
	return err;
	}

	C2Allocator::id_t mId;
	C2HandleBuf mHandle;
	c2_status_t mInit;
	struct Mapping {
	void* addr;
	size_t alignmentBytes;
	size_t size;
	};
	Mutexed<std::list<Mapping>> mMappings;

	// TODO: we could make this encapsulate shared_ptr and copiable
	C2_DO_NOT_COPY(C2DmaBufAllocation);
	};

	c2_status_t C2DmaBufAllocation::map(size_t offset, size_t size, C2MemoryUsage usage, C2Fence* fence,
	void** addr) {
	(void)fence; // TODO: wait for fence
	*addr = nullptr;
	if (!mMappings.lock()->empty()) {
	ALOGV("multiple map");
	// TODO: technically we should return DUPLICATE here, but our block views
	// don't actually unmap, so we end up remapping the buffer multiple times.
	//
	// return C2_DUPLICATE;
	}
	if (size == 0) {
	return C2_BAD_VALUE;
	}

	int prot = PROT_NONE;
	int flags = MAP_SHARED;
	if (usage.expected & C2MemoryUsage::CPU_READ) {
	prot \|= PROT_READ;
	}
	if (usage.expected & C2MemoryUsage::CPU_WRITE) {
	prot \|= PROT_WRITE;
	}

	size_t alignmentBytes = offset % PAGE_SIZE;
	size_t mapOffset = offset - alignmentBytes;
	size_t mapSize = size + alignmentBytes;
	Mapping map = {nullptr, alignmentBytes, mapSize};

	c2_status_t err =
	mapInternal(mapSize, mapOffset, alignmentBytes, prot, flags, &(map.addr), addr);
	if (map.addr) {
	mMappings.lock()->push_back(map);
	}
	return err;
	}

	c2_status_t C2DmaBufAllocation::unmap(void* addr, size_t size, C2Fence* fence) {
	Mutexed<std::list<Mapping>>::Locked mappings(mMappings);
	if (mappings->empty()) {
	ALOGD("tried to unmap unmapped buffer");
	return C2_NOT_FOUND;
	}
	for (auto it = mappings->begin(); it != mappings->end(); ++it) {
	if (addr != (uint8_t*)it->addr + it->alignmentBytes \|\|
	size + it->alignmentBytes != it->size) {
	continue;
	}
	int err = munmap(it->addr, it->size);
	if (err != 0) {
	ALOGD("munmap failed");
	return c2_map_errno<EINVAL>(errno);
	}
	if (fence) {
	*fence = C2Fence(); // not using fences
	}
	(void)mappings->erase(it);
	ALOGV("successfully unmapped: %d", mHandle.bufferFd());
	return C2_OK;
	}
	ALOGD("unmap failed to find specified map");
	return C2_BAD_VALUE;
	}

	c2_status_t C2DmaBufAllocation::status() const {
	return mInit;
	}

	C2Allocator::id_t C2DmaBufAllocation::getAllocatorId() const {
	return mId;
	}

	bool C2DmaBufAllocation::equals(const std::shared_ptr<C2LinearAllocation>& other) const {
	if (!other \|\| other->getAllocatorId() != getAllocatorId()) {
	return false;
	}
	// get user handle to compare objects
	std::shared_ptr<C2DmaBufAllocation> otherAsBuf =
	std::static_pointer_cast<C2DmaBufAllocation>(other);
	return mHandle.bufferFd() == otherAsBuf->mHandle.bufferFd();
	}

	const C2Handle* C2DmaBufAllocation::handle() const {
	return &mHandle;
	}

	C2DmaBufAllocation::~C2DmaBufAllocation() {
	Mutexed<std::list<Mapping>>::Locked mappings(mMappings);
	if (!mappings->empty()) {
	ALOGD("Dangling mappings!");
	for (const Mapping& map : *mappings) {
	int err = munmap(map.addr, map.size);
	if (err) ALOGD("munmap failed");
	}
	}
	if (mInit == C2_OK) {
	native_handle_close(&mHandle);
	}
	}

	C2DmaBufAllocation::C2DmaBufAllocation(BufferAllocator& alloc, size_t allocSize, size_t capacity,
	C2String heap_name, unsigned flags, C2Allocator::id_t id)
	: C2LinearAllocation(capacity), mHandle(-1, 0) {
	int bufferFd = -1;
	int ret = 0;

	bufferFd = alloc.Alloc(heap_name, allocSize, flags);
	if (bufferFd < 0) {
	ret = bufferFd;
	}

	// this may be a non-working handle if bufferFd is negative
	mHandle = C2HandleBuf(bufferFd, capacity);
	mId = id;
	mInit = c2_status_t(c2_map_errno<ENOMEM, EACCES, EINVAL>(ret));
	}

	C2DmaBufAllocation::C2DmaBufAllocation(size_t size, int shareFd, C2Allocator::id_t id)
	: C2LinearAllocation(size), mHandle(-1, 0) {
	mHandle = C2HandleBuf(shareFd, size);
	mId = id;
	mInit = c2_status_t(c2_map_errno<ENOMEM, EACCES, EINVAL>(0));
	}

	/* =========================== DMABUF ALLOCATOR =========================== */
	C2DmaBufAllocator::C2DmaBufAllocator(id_t id) : mInit(C2_OK) {
	C2MemoryUsage minUsage = {0, 0};
	C2MemoryUsage maxUsage = {C2MemoryUsage::CPU_READ, C2MemoryUsage::CPU_WRITE};
	Traits traits = {"android.allocator.dmabuf", id, LINEAR, minUsage, maxUsage};
	mTraits = std::make_shared<Traits>(traits);
	}

	C2Allocator::id_t C2DmaBufAllocator::getId() const {
	std::lock_guard<std::mutex> lock(mUsageMapperLock);
	return mTraits->id;
	}

	C2String C2DmaBufAllocator::getName() const {
	std::lock_guard<std::mutex> lock(mUsageMapperLock);
	return mTraits->name;
	}

	std::shared_ptr<const C2Allocator::Traits> C2DmaBufAllocator::getTraits() const {
	std::lock_guard<std::mutex> lock(mUsageMapperLock);
	return mTraits;
	}

	void C2DmaBufAllocator::setUsageMapper(const UsageMapperFn& mapper __unused, uint64_t minUsage,
	uint64_t maxUsage, uint64_t blockSize) {
	std::lock_guard<std::mutex> lock(mUsageMapperLock);
	mUsageMapperCache.clear();
	mUsageMapperLru.clear();
	mUsageMapper = mapper;
	Traits traits = {mTraits->name, mTraits->id, LINEAR, C2MemoryUsage(minUsage),
	C2MemoryUsage(maxUsage)};
	mTraits = std::make_shared<Traits>(traits);
	mBlockSize = blockSize;
	}

	std::size_t C2DmaBufAllocator::MapperKeyHash::operator()(const MapperKey& k) const {
	return std::hash<uint64_t>{}(k.first) ^ std::hash<size_t>{}(k.second);
	}

	c2_status_t C2DmaBufAllocator::mapUsage(C2MemoryUsage usage, size_t capacity, C2String* heap_name,
	unsigned* flags) {
	std::lock_guard<std::mutex> lock(mUsageMapperLock);
	c2_status_t res = C2_OK;
	// align capacity
	capacity = (capacity + mBlockSize - 1) & ~(mBlockSize - 1);
	MapperKey key = std::make_pair(usage.expected, capacity);
	auto entry = mUsageMapperCache.find(key);
	if (entry == mUsageMapperCache.end()) {
	if (mUsageMapper) {
	res = mUsageMapper(usage, capacity, heap_name, flags);
	} else {
	if (C2DmaBufAllocator::system_uncached_supported() &&
	!(usage.expected & (C2MemoryUsage::CPU_READ \| C2MemoryUsage::CPU_WRITE)))
	*heap_name = "system-uncached";
	else
	*heap_name = "system";
	*flags = 0;
	res = C2_NO_INIT;
	}
	// add usage to cache
	MapperValue value = std::make_tuple(heap_name, flags, res);
	mUsageMapperLru.emplace_front(key, value);
	mUsageMapperCache.emplace(std::make_pair(key, mUsageMapperLru.begin()));
	if (mUsageMapperCache.size() > USAGE_LRU_CACHE_SIZE) {
	// remove LRU entry
	MapperKey lruKey = mUsageMapperLru.front().first;
	mUsageMapperCache.erase(lruKey);
	mUsageMapperLru.pop_back();
	}
	} else {
	// move entry to MRU
	mUsageMapperLru.splice(mUsageMapperLru.begin(), mUsageMapperLru, entry->second);
	const MapperValue& value = entry->second->second;
	std::tie(heap_name, flags, res) = value;
	}
	return res;
	}

	c2_status_t C2DmaBufAllocator::newLinearAllocation(
	uint32_t capacity, C2MemoryUsage usage, std::shared_ptr<C2LinearAllocation>* allocation) {
	if (allocation == nullptr) {
	return C2_BAD_VALUE;
	}

	allocation->reset();
	if (mInit != C2_OK) {
	return mInit;
	}

	C2String heap_name;
	unsigned flags = 0;
	c2_status_t ret = mapUsage(usage, capacity, &heap_name, &flags);
	if (ret && ret != C2_NO_INIT) {
	return ret;
	}

	// TODO: should we pad before mapping usage?

	// NOTE: read this property directly from the property as this code has to run on
	// Android Q, but the sysprop was only introduced in Android S.
	static size_t sPadding =
	base::GetUintProperty("media.c2.dmabuf.padding", (uint32_t)0, MAX_PADDING);
	if (sPadding > SIZE_MAX - capacity) {
	// size would overflow
	ALOGD("dmabuf_alloc: size #%x cannot accommodate padding #%zx", capacity, sPadding);
	return C2_NO_MEMORY;
	}

	size_t allocSize = (size_t)capacity + sPadding;
	// TODO: should we align allocation size to mBlockSize to reflect the true allocation size?
	std::shared_ptr<C2DmaBufAllocation> alloc = std::make_shared<C2DmaBufAllocation>(
	mBufferAllocator, allocSize, allocSize - sPadding, heap_name, flags, getId());
	ret = alloc->status();
	if (ret == C2_OK) {
	*allocation = alloc;
	}
	return ret;
	}

	c2_status_t C2DmaBufAllocator::priorLinearAllocation(
	const C2Handle* handle, std::shared_ptr<C2LinearAllocation>* allocation) {
	*allocation = nullptr;
	if (mInit != C2_OK) {
	return mInit;
	}

	if (!C2HandleBuf::IsValid(handle)) {
	return C2_BAD_VALUE;
	}

	// TODO: get capacity and validate it
	const C2HandleBuf* h = static_cast<const C2HandleBuf*>(handle);
	std::shared_ptr<C2DmaBufAllocation> alloc =
	std::make_shared<C2DmaBufAllocation>(h->size(), h->bufferFd(), getId());
	c2_status_t ret = alloc->status();
	if (ret == C2_OK) {
	*allocation = alloc;
	native_handle_delete(
	const_cast<native_handle_t>(reinterpret_cast<const native_handle_t>(handle)));
	}
	return ret;
	}

	// static
	bool C2DmaBufAllocator::CheckHandle(const C2Handle* const o) {
	return C2HandleBuf::IsValid(o);
	}

	} // namespace android