diff --git a/os/include/block/component.h b/os/include/block/component.h
index 3e608e9aa8..b383870dc3 100644
--- a/os/include/block/component.h
+++ b/os/include/block/component.h
@@ -104,25 +104,26 @@ namespace Block {
 					}
 			};
 
-			Driver_factory       &_driver_factory;
-			Driver               &_driver;
-			Dataspace_capability  _rq_ds;
-			Rq_thread             _rq_thread;
+			Driver_factory           &_driver_factory;
+			Driver                   &_driver;
+			Ram_dataspace_capability  _rq_ds;
+			Rq_thread                 _rq_thread;
 
 		public:
 
 			/**
 			 * Constructor
 			 */
-			Session_component(Dataspace_capability  rq_ds,
-			                  Driver_factory       &driver_factory,
-			                  Rpc_entrypoint       &ep)
+			Session_component(Ram_dataspace_capability  rq_ds,
+			                  Driver                   &driver,
+			                  Driver_factory           &driver_factory,
+			                  Rpc_entrypoint           &ep)
 			:
 				Session_rpc_object(rq_ds, ep),
 				_driver_factory(driver_factory),
-				_driver(*_driver_factory.create()),
+				_driver(driver),
 				_rq_ds(rq_ds),
-				_rq_thread(tx_sink(), _driver, Dataspace_client(rq_ds).phys_addr())
+				_rq_thread(tx_sink(), _driver, Dataspace_client(_rq_ds).phys_addr())
 			{ }
 
 			/**
@@ -188,9 +189,11 @@ namespace Block {
 					throw Root::Quota_exceeded();
 				}
 
+				Driver * driver = _driver_factory.create();
+				Ram_dataspace_capability ds_cap;
+				ds_cap = driver->alloc_dma_buffer(tx_buf_size);
 				return new (md_alloc())
-					Session_component(env()->ram_session()->alloc(tx_buf_size, false),
-					                  _driver_factory, _ep);
+					Session_component(ds_cap, *driver, _driver_factory, _ep);
 			}
 
 		public:
diff --git a/os/include/block/driver.h b/os/include/block/driver.h
index bbab5290ca..5a1aafdbdd 100644
--- a/os/include/block/driver.h
+++ b/os/include/block/driver.h
@@ -18,6 +18,8 @@
 #include <base/exception.h>
 #include <base/stdint.h>
 
+#include <ram_session/ram_session.h>
+
 
 namespace Block {
 
@@ -91,6 +93,11 @@ namespace Block {
 		 * \return  true if DMA is enabled, false otherwise
 		 */
 		virtual bool dma_enabled() = 0;
+
+		/**
+		 * Allocate buffer which is suitable for DMA.
+		 */
+		virtual Genode::Ram_dataspace_capability alloc_dma_buffer(Genode::size_t) = 0;
 	};
 
 
diff --git a/os/include/pci_session/client.h b/os/include/pci_session/client.h
index 302bb108a0..a28ea78b1a 100644
--- a/os/include/pci_session/client.h
+++ b/os/include/pci_session/client.h
@@ -35,6 +35,10 @@ namespace Pci {
 
 		Genode::Io_mem_dataspace_capability config_extended(Device_capability device_cap) {
 			return call<Rpc_config_extended>(device_cap); }
+
+		Genode::Ram_dataspace_capability alloc_dma_buffer(Device_capability device_cap,
+		                                                  Genode::size_t size) {
+			return call<Rpc_alloc_dma_buffer>(device_cap, size); }
 	};
 }
 
diff --git a/os/include/pci_session/pci_session.h b/os/include/pci_session/pci_session.h
index 53cd2c25dc..3cff3ae83a 100644
--- a/os/include/pci_session/pci_session.h
+++ b/os/include/pci_session/pci_session.h
@@ -16,6 +16,7 @@
 
 #include <pci_device/pci_device.h>
 #include <session/session.h>
+#include <ram_session/ram_session.h>
 
 namespace Pci {
 
@@ -55,6 +56,11 @@ namespace Pci {
 		 */
 		virtual Genode::Io_mem_dataspace_capability config_extended(Device_capability) = 0;
 
+		/**
+		 * Allocate memory suitable for DMA.
+		 */
+		virtual Genode::Ram_dataspace_capability alloc_dma_buffer(Device_capability,
+		                                                          Genode::size_t) = 0;
 		/*********************
 		 ** RPC declaration **
 		 *********************/
@@ -65,9 +71,14 @@ namespace Pci {
 		GENODE_RPC(Rpc_release_device, void, release_device, Device_capability);
 		GENODE_RPC(Rpc_config_extended, Genode::Io_mem_dataspace_capability,
 		           config_extended, Device_capability);
+		GENODE_RPC_THROW(Rpc_alloc_dma_buffer, Genode::Ram_dataspace_capability,
+		                 alloc_dma_buffer,
+		                 GENODE_TYPE_LIST(Genode::Ram_session::Quota_exceeded),
+		                 Device_capability, Genode::size_t);
 
 		GENODE_RPC_INTERFACE(Rpc_first_device, Rpc_next_device,
-		                     Rpc_release_device, Rpc_config_extended);
+		                     Rpc_release_device, Rpc_config_extended,
+		                     Rpc_alloc_dma_buffer);
 	};
 }
 
diff --git a/os/src/drivers/ahci/main.cc b/os/src/drivers/ahci/main.cc
index 3b3eea097a..7c669a44bb 100644
--- a/os/src/drivers/ahci/main.cc
+++ b/os/src/drivers/ahci/main.cc
@@ -770,6 +770,9 @@ class Ahci_driver : public Block::Driver
 			PERR("%s should not be called", __PRETTY_FUNCTION__);
 			throw Io_error();
 		}
+
+		Ram_dataspace_capability alloc_dma_buffer(size_t size) {
+			return env()->ram_session()->alloc(size); }
 };
 
 
diff --git a/os/src/drivers/pci/pci_session_component.h b/os/src/drivers/pci/pci_session_component.h
index e7398d84fe..aee6709c1d 100644
--- a/os/src/drivers/pci/pci_session_component.h
+++ b/os/src/drivers/pci/pci_session_component.h
@@ -291,6 +291,10 @@ namespace Pci {
 
 				return io_mem->dataspace();
 			}
+
+			Genode::Ram_dataspace_capability alloc_dma_buffer(Device_capability device_cap,
+			                                                  Genode::size_t size) {
+				return Genode::env()->ram_session()->alloc(size, false); }
 	};
 
 
diff --git a/os/src/drivers/sd_card/omap4/driver.h b/os/src/drivers/sd_card/omap4/driver.h
index c03484798a..e65f07261f 100644
--- a/os/src/drivers/sd_card/omap4/driver.h
+++ b/os/src/drivers/sd_card/omap4/driver.h
@@ -119,6 +119,10 @@ class Block::Omap4_driver : public Block::Driver
 		}
 
 		bool dma_enabled() { return _use_dma; }
+
+		Ram_dataspace_capability alloc_dma_buffer(size_t size) {
+			/* unused */
+			return Ram_dataspace_capability(); }
 };
 
 #endif /* _DRIVER_H_ */
diff --git a/os/src/drivers/sd_card/sd_card.h b/os/src/drivers/sd_card/sd_card.h
index 322f22c8dd..837ca42151 100644
--- a/os/src/drivers/sd_card/sd_card.h
+++ b/os/src/drivers/sd_card/sd_card.h
@@ -130,6 +130,11 @@ class Sd_card : public Block::Driver
 			throw Io_error(); }
 
 		bool dma_enabled() { return false; }
+
+		Genode::Ram_dataspace_capability alloc_dma_buffer(Genode::size_t size)
+		{
+			return Genode::env()->ram_session()->alloc(size, false);
+		}
 };
 
 #endif /* _SD_CARD_H_ */