CLMiner, query only GPU devices

By default now, CPU is not considered an OpenCL device.

Also added a new argument --allow-opencl-cpu, that would allow OpenCL to
include CPU devices if the user's openCL implementation caters for it.

ethminer/MinerAux.h

@@ -132,6 +132,8 @@ public:
 			ProofOfWork::GPUMiner::listDevices();
 			exit(0);
 		}
+		else if (arg == "--allow-opencl-cpu")
+			ProofOfWork::GPUMiner::allowCPU();
 		else if (arg == "--phone-home" && i + 1 < argc)
 		{
 			string m = argv[++i];

libethash-cl/ethash_cl_miner.cpp

@@ -51,6 +51,8 @@ using namespace std;
 
 // TODO: If at any point we can use libdevcore in here then we should switch to using a LogChannel
 #define ETHCL_LOG(_contents) cout << "[OPENCL]:" << _contents << endl
+// Types of OpenCL devices we are interested in
+#define ETHCL_QUERIED_DEVICE_TYPES (CL_DEVICE_TYPE_GPU | CL_DEVICE_TYPE_ACCELERATOR)
 
 static void addDefinition(string& _source, char const* _id, unsigned _value)
 {
@@ -82,9 +84,8 @@ string ethash_cl_miner::platform_info(unsigned _platformId, unsigned _deviceId)
 	}
 
 	// get GPU device of the selected platform
-	vector<cl::Device> devices;
 	unsigned platform_num = min<unsigned>(_platformId, platforms.size() - 1);
-	platforms[platform_num].getDevices(CL_DEVICE_TYPE_ALL, &devices);
+	vector<cl::Device> devices = getDevices(platforms, _platformId);
 	if (devices.empty())
 	{
 		ETHCL_LOG("No OpenCL devices found.");
@@ -99,6 +100,17 @@ string ethash_cl_miner::platform_info(unsigned _platformId, unsigned _deviceId)
 	return "{ \"platform\": \"" + platforms[platform_num].getInfo<CL_PLATFORM_NAME>() + "\", \"device\": \"" + device.getInfo<CL_DEVICE_NAME>() + "\", \"version\": \"" + device_version + "\" }";
 }
 
+std::vector<cl::Device> ethash_cl_miner::getDevices(std::vector<cl::Platform> const& _platforms, unsigned _platformId)
+{
+	vector<cl::Device> devices;
+	unsigned platform_num = min<unsigned>(_platformId, _platforms.size() - 1);
+	_platforms[platform_num].getDevices(
+		s_allowCPU ? CL_DEVICE_TYPE_ALL : ETHCL_QUERIED_DEVICE_TYPES,
+		&devices
+	);
+	return devices;
+}
+
 unsigned ethash_cl_miner::getNumPlatforms()
 {
 	vector<cl::Platform> platforms;
@@ -116,9 +128,7 @@ unsigned ethash_cl_miner::getNumDevices(unsigned _platformId)
 		return 0;
 	}
 
-	vector<cl::Device> devices;
-	unsigned platform_num = min<unsigned>(_platformId, platforms.size() - 1);
-	platforms[platform_num].getDevices(CL_DEVICE_TYPE_ALL, &devices);
+	vector<cl::Device> devices = getDevices(platforms, _platformId);
 	if (devices.empty())
 	{
 		ETHCL_LOG("No OpenCL devices found.");
@@ -152,6 +162,13 @@ bool ethash_cl_miner::configureGPU()
 	);
 }
 
+bool ethash_cl_miner::s_allowCPU = false;
+
+void ethash_cl_miner::allowCPU()
+{
+	s_allowCPU = true;
+}
+
 bool ethash_cl_miner::searchForAllDevices(function<bool(cl::Device const&)> _callback)
 {
 	vector<cl::Platform> platforms;
@@ -175,8 +192,7 @@ bool ethash_cl_miner::searchForAllDevices(unsigned _platformId, function<bool(cl
 	if (_platformId >= platforms.size())
 		return false;
 
-	vector<cl::Device> devices;
-	platforms[_platformId].getDevices(CL_DEVICE_TYPE_ALL, &devices);
+	vector<cl::Device> devices = getDevices(platforms, _platformId);
 	for (cl::Device const& device: devices)
 		if (_callback(device))
 			return true;
@@ -204,8 +220,7 @@ void ethash_cl_miner::doForAllDevices(unsigned _platformId, function<void(cl::De
 	if (_platformId >= platforms.size())
 		return;
 
-	vector<cl::Device> devices;
-	platforms[_platformId].getDevices(CL_DEVICE_TYPE_ALL, &devices);
+	vector<cl::Device> devices = getDevices(platforms, _platformId);
 	for (cl::Device const& device: devices)
 		_callback(device);
 }
@@ -253,8 +268,7 @@ bool ethash_cl_miner::init(
 		ETHCL_LOG("Using platform: " << platforms[_platformId].getInfo<CL_PLATFORM_NAME>().c_str());
 
 		// get GPU device of the default platform
-		vector<cl::Device> devices;
-		platforms[_platformId].getDevices(CL_DEVICE_TYPE_ALL, &devices);
+		vector<cl::Device> devices = getDevices(platforms, _platformId);
 		if (devices.empty())
 		{
 			ETHCL_LOG("No OpenCL devices found.");

libethash-cl/ethash_cl_miner.h

@@ -41,6 +41,7 @@ public:
 	static std::string platform_info(unsigned _platformId = 0, unsigned _deviceId = 0);
 	static void listDevices();
 	static bool configureGPU();
+	static void allowCPU();
 
 	bool init(
 		uint8_t const* _dag,
@@ -56,6 +57,9 @@ public:
 	void search_chunk(uint8_t const* header, uint64_t target, search_hook& hook);
 
 private:
+
+	static std::vector<cl::Device> getDevices(std::vector<cl::Platform> const& _platforms, unsigned _platformId);
+	
 	enum { c_max_search_results = 63, c_num_buffers = 2, c_hash_batch_size = 1024, c_search_batch_size = 1024*256 };
 
 	cl::Context m_context;
@@ -70,4 +74,5 @@ private:
 	unsigned m_workgroup_size;
 	bool m_opencl_1_1;
 
+	static bool s_allowCPU;
 };

libethash-cl/ethash_cl_miner_kernel.cl

@@ -275,8 +275,6 @@ uint inner_loop_chunks(uint4 init, uint thread_id, __local uint* share, __global
 	return fnv_reduce(mix);
 }
 
-
-
 uint inner_loop(uint4 init, uint thread_id, __local uint* share, __global hash128_t const* g_dag, uint isolate)
 {
 	uint4 mix = init;
@@ -585,4 +583,4 @@ __kernel void ethash_search_chunks(
 		uint slot = min(convert_uint(MAX_OUTPUTS), convert_uint(atomic_inc(&g_output[0]) + 1));
 		g_output[slot] = gid;
 	}
-}
+}

libethcore/Ethash.cpp

@@ -366,6 +366,11 @@ void Ethash::GPUMiner::pause()
 	stopWorking();
 }
 
+void Ethash::GPUMiner::allowCPU()
+{
+	return ethash_cl_miner::allowCPU();
+}
+
 std::string Ethash::GPUMiner::platformInfo()
 {
 	return ethash_cl_miner::platform_info(s_platformId, s_deviceId);

libethcore/Ethash.h

@@ -92,6 +92,7 @@ public:
 		static void setDefaultDevice(unsigned) {}
 		static void listDevices() {}
 		static bool configureGPU() { return false; }
+		static void allowCPU() {}
 		static void setNumInstances(unsigned _instances) { s_numInstances = std::min<unsigned>(_instances, std::thread::hardware_concurrency()); }
 	protected:
 		void kickOff() override
@@ -121,6 +122,7 @@ public:
 		static unsigned getNumDevices();
 		static void listDevices();
 		static bool configureGPU();
+		static void allowCPU();
 		static void setDefaultPlatform(unsigned _id) { s_platformId = _id; }
 		static void setDefaultDevice(unsigned _id) { s_deviceId = _id; }
 		static void setNumInstances(unsigned _instances) { s_numInstances = std::min<unsigned>(_instances, getNumDevices()); }