// Copyright 2019 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "msd_img_connection.h"

#include <atomic>

#include "include/fuchsia_communication.h"
#include "msd_img_buffer.h"
#include "msd_img_semaphore.h"
#include "platform_trace.h"

extern "C"
{
#include "process_stats.h"
#include "pvrsrv.h"
#include "pvrsrv_error.h"
#include "srvcore.h"
#include "rgxdevice.h"
}


static thread_local MsdImgConnection *current_connection;

class ScopedSetConnection
{
public:
	explicit ScopedSetConnection(MsdImgConnection *connection)
	{
		DASSERT(!current_connection);
		current_connection = connection;
	}
	~ScopedSetConnection()
	{
		DASSERT(current_connection);
		current_connection = nullptr;
	}
};


MsdImgConnection::MsdImgConnection(Owner *owner, msd_client_id_t client_id) : owner_(owner), client_id_(client_id)
{
	magic_ = kMagic;
	snprintf(client_name_, sizeof(client_name_), "Client ID %d", client_id);
}

MsdImgConnection::~MsdImgConnection()
{
	ScopedSetConnection set_connection(this);
	if (connection_data_)
	{
		PVRSRVConnectionDisconnect(connection_data_);
	}
	magic_ = 0;
}

MsdImgConnection *
MsdImgConnection::GetCurrentConnection()
{
	return current_connection;
}

bool
MsdImgConnection::Init()
{
	ScopedSetConnection set_connection(this);
	void *data;
	PVRSRV_ERROR srv_err = PVRSRVConnectionConnect(&data, this);
	if (srv_err != PVRSRV_OK)
	{
		return DRETF(false, "Failed to create PVRSRV connection: %d", srv_err);
	}
	connection_data_ = reinterpret_cast<CONNECTION_DATA *>(data);
	return true;
}

magma_status_t
MsdImgConnection::ProcessCommandBuffer(magma_system_command_buffer *command_buffer,
				       magma_system_exec_resource *exec_resources,
				       msd_buffer_t **buffers,
				       msd_semaphore_t **signal_semaphores,
				       PVRSRV_BRIDGE_PACKAGE *package_out,
				       volatile FuchsiaImgCommandPayload **payload_out,
				       std::vector<std::shared_ptr<MsdImgSemaphore>> *semaphores_out)
{
	uint32_t num_resources = command_buffer->resource_count;
	uint32_t num_semaphores = command_buffer->signal_semaphore_count;

	// Array and payload buffers.
	constexpr uint32_t kExpectedResourceCount = 1;
	if (num_resources < kExpectedResourceCount)
	{
		return DRET_MSG(MAGMA_STATUS_INVALID_ARGS, "num_resources %d too small", num_resources);
	}
	if (num_semaphores < kSemaphoreMax)
	{
		return DRET_MSG(MAGMA_STATUS_INVALID_ARGS, "num_semaphores %d too small", num_semaphores);
	}

	// Assume the exec resources are in this order.
	std::shared_ptr<MsdImgBuffer> payload_buffer = MsdImgAbiBuffer::cast(buffers[0])->base_ptr();

	volatile FuchsiaImgCommandPayload *payload;
	if (payload_buffer->platform_buffer()->size() < sizeof(*payload))
	{
		return DRET_MSG(MAGMA_STATUS_INVALID_ARGS, "Payload buffer too small for struct");
	}
	void *data;
	if (!payload_buffer->GetPersistentCpuMap(&data))
	{
		return DRET_MSG(MAGMA_STATUS_INTERNAL_ERROR, "Unable to make persistent map");
	}

	payload = reinterpret_cast<volatile FuchsiaImgCommandPayload *>(data);

	package_out->ui32BridgeID = payload->bridge_group;
	package_out->ui32FunctionID = payload->function_id;
	package_out->ui32Size = sizeof(*package_out);
	package_out->ui32InBufferSize = payload->in_data_size;
	package_out->ui32OutBufferSize = payload->out_data_size;

	const uint64_t remaining_buffer_size = payload_buffer->platform_buffer()->size() - sizeof(*payload);

	if (remaining_buffer_size < package_out->ui32InBufferSize)
	{
		return DRET_MSG(MAGMA_STATUS_INVALID_ARGS, "Payload buffer too small for in args");
	}
	if (remaining_buffer_size < package_out->ui32OutBufferSize)
	{
		return DRET_MSG(MAGMA_STATUS_INVALID_ARGS, "Payload buffer too small for out args");
	}
	// Volatile isn't necessary because the bridge code will memcpy everything
	// before using it.
	package_out->pvParamIn = reinterpret_cast<void *>(const_cast<FuchsiaImgCommandPayload *>(payload + 1));
	package_out->pvParamOut = package_out->pvParamIn;
	payload_buffer_ = payload_buffer;
	current_client_thread_id_ = payload->thread_id;
	*payload_out = payload;
	semaphores_out->push_back(MsdImgAbiSemaphore::cast(signal_semaphores[0])->base_ptr());
	if (num_semaphores > 1)
	{
		additional_semaphore_ = MsdImgAbiSemaphore::cast(signal_semaphores[1])->base_ptr();
	}

	if (num_resources > kExpectedResourceCount)
	{
		additional_buffer_ = MsdImgAbiBuffer::cast(buffers[1])->base_ptr();
	}
	return MAGMA_STATUS_OK;
}

void
MsdImgConnection::CleanupAfterCommand(volatile FuchsiaImgCommandPayload *payload,
				      const std::vector<std::shared_ptr<MsdImgSemaphore>> &semaphores,
				      bool success)
{
	payload->success = success;

	semaphores[kSemaphoreCompletion]->platform_semaphore()->Signal();
	// The semaphore signal should happen before |finished_command| is set
        // as otherwise the client may reuse this payload buffer too quickly and
        // think the next command put in the buffer was completed too early.
	std::atomic_thread_fence(std::memory_order_release);
	payload->finished_command = 1;
	payload_buffer_ = nullptr;
	additional_buffer_.reset();
	additional_semaphore_.reset();
	current_client_thread_id_ = 0;
}

magma_status_t
MsdImgConnection::ExecuteCommandBuffer(magma_system_command_buffer *command_buffer,
				       magma_system_exec_resource *exec_resources,
				       msd_buffer_t **buffers,
				       msd_semaphore_t **signal_semaphores)
{
	PVRSRV_BRIDGE_PACKAGE package;
	volatile FuchsiaImgCommandPayload *payload;
	std::vector<std::shared_ptr<MsdImgSemaphore>> semaphores;
	magma_status_t status = ProcessCommandBuffer(command_buffer, exec_resources, buffers, signal_semaphores, &package,
						     &payload, &semaphores);
	if (status != MAGMA_STATUS_OK)
		return DRET(status);

	PVRSRV_ERROR eError;
	{
		TRACE_DURATION("gfx", "MsdImgConnection::ExecuteCommandBuffer", "bridge group", package.ui32BridgeID,
			       "function", package.ui32FunctionID);
		ScopedSetConnection set_connection(this);

		eError = BridgedDispatchKM(connection_data_, &package);
	}
	CleanupAfterCommand(payload, semaphores, eError == PVRSRV_OK);

	if (eError != PVRSRV_OK)
		return DRET_MSG(MAGMA_STATUS_INTERNAL_ERROR, "Bridge error: %d", eError);
	return MAGMA_STATUS_OK;
}

std::shared_ptr<MsdImgBuffer>
MsdImgConnection::TakeAdditionalBuffer()
{
	// Move should reset |additional_buffer_|.
	return std::move(additional_buffer_);
}

std::shared_ptr<MsdImgSemaphore>
MsdImgConnection::TakeAdditionalSemaphore()
{
	// Move should reset |additional_semaphore_|.
	return std::move(additional_semaphore_);
}

bool
MsdImgConnection::CopyFromUser(void *dest, const void *src, uint32_t size)
{
	DASSERT(payload_buffer_);
	uint64_t src_offset = reinterpret_cast<uint64_t>(src);
	if (src_offset + size > payload_buffer_->platform_buffer()->size())
	{
		return DRETF(false, "CopyFromUser out of bounds 0x%lx 0x%x 0x%lx", src_offset, size,
			     payload_buffer_->platform_buffer()->size());
	}
	return payload_buffer_->platform_buffer()->Read(dest, src_offset, size);
}

bool
MsdImgConnection::CopyToUser(void *dest, const void *src, uint32_t size)
{
	DASSERT(payload_buffer_);
	uint64_t dest_offset = reinterpret_cast<uint64_t>(dest);
	if (dest_offset + size > payload_buffer_->platform_buffer()->size())
	{
		return DRETF(false, "CopyToUser out of bounds 0x%lx 0x%x 0x%lx", dest_offset, size,
			     payload_buffer_->platform_buffer()->size());
	}
	return payload_buffer_->platform_buffer()->Write(src, dest_offset, size);
}

PVRSRV_DEVICE_NODE *
OSGetDevData(CONNECTION_DATA *psConnection)
{
	MsdImgConnection *connection = MsdImgConnection::Cast(psConnection->hOsPrivateData);

	return connection->owner()->device_node();
}

PVRSRV_ERROR
OSConnectionPrivateDataInit(IMG_HANDLE *phOsPrivateData, void *pvOSData)
{
	*phOsPrivateData = pvOSData;
	return PVRSRV_OK;
}

PVRSRV_ERROR
OSConnectionPrivateDataDeInit(IMG_HANDLE hOsPrivateData)
{
	// Data should be freed by connection close.
	return PVRSRV_OK;
}