gpu_session: add PPGTT address query function

Using the 'query_buffer_ppgtt()' function allows for retrieving the
virtual address of the buffer in the PPGTT.

This is for components that manage the GPU virtual addresses rather than
the client as is the case with the lima driver.

Issue #4559.

repos/os/include/gpu_session/client.h

@@ -76,6 +76,9 @@ class Gpu::Session_client : public Genode::Rpc_client<Session>
 		void unmap_buffer_ppgtt(Buffer_id id, Gpu::addr_t va) override {
 			call<Rpc_unmap_buffer_ppgtt>(id, va); }
 
+		Gpu::addr_t query_buffer_ppgtt(Gpu::Buffer_id id) override {
+			return call<Rpc_query_buffer_ppgtt>(id); }
+
 		bool set_tiling(Buffer_id id, unsigned mode) override {
 			return call<Rpc_set_tiling>(id, mode); }
 };

repos/os/include/gpu_session/gpu_session.h

@@ -197,7 +197,14 @@ struct Gpu::Session : public Genode::Session
 	 *
 	 * \param id  buffer id
 	 */
-	virtual void unmap_buffer_ppgtt(Buffer_id id, Gpu::addr_t) = 0;
+	virtual void unmap_buffer_ppgtt(Buffer_id id, Gpu::addr_t va) = 0;
+
+	/**
+	 * Get virtual address of buffer in the PPGTT
+	 *
+	 * \param id  buffer id to be associated with the buffer
+	 */
+	virtual Gpu::addr_t query_buffer_ppgtt(Buffer_id) = 0;
 
 	/**
 	 * Set tiling for buffer
@@ -237,6 +244,7 @@ struct Gpu::Session : public Genode::Session
 	                 Gpu::Buffer_id, Gpu::addr_t);
 	GENODE_RPC(Rpc_unmap_buffer_ppgtt, void, unmap_buffer_ppgtt,
 	           Gpu::Buffer_id, Gpu::addr_t);
+	GENODE_RPC(Rpc_query_buffer_ppgtt, Gpu::addr_t, query_buffer_ppgtt, Gpu::Buffer_id);
 	GENODE_RPC(Rpc_set_tiling, bool, set_tiling,
 	           Gpu::Buffer_id, unsigned);
 
@@ -244,7 +252,7 @@ struct Gpu::Session : public Genode::Session
 	                     Rpc_complete, Rpc_completion_sigh, Rpc_alloc_buffer,
 	                     Rpc_free_buffer, Rpc_export_buffer, Rpc_import_buffer,
 	                     Rpc_map_buffer, Rpc_unmap_buffer,
-	                     Rpc_map_buffer_ppgtt, Rpc_unmap_buffer_ppgtt,
+	                     Rpc_map_buffer_ppgtt, Rpc_unmap_buffer_ppgtt, Rpc_query_buffer_ppgtt,
 	                     Rpc_set_tiling);
 };
 

repos/os/src/drivers/gpu/intel/main.cc

@@ -2016,6 +2016,23 @@ class Gpu::Session_component : public Genode::Session_object<Gpu::Session>
 			_apply_buffer_local(id, lookup_and_unmap);
 		}
 
+		Gpu::addr_t query_buffer_ppgtt(Gpu::Buffer_id id) override
+		{
+			Gpu::addr_t result = (Gpu::addr_t)-1;
+
+			auto lookup_va = [&] (Buffer_local &buffer_local) {
+
+				if (!buffer_local.ppgtt_va_valid) {
+					Genode::error("buffer not mapped");
+					return;
+				}
+
+				result = buffer_local.ppgtt_va;
+			};
+			_apply_buffer_local(id, lookup_va);
+			return result;
+		}
+
 		bool set_tiling(Gpu::Buffer_id id,
 		                Genode::uint32_t const mode) override
 		{

repos/os/src/server/black_hole/gpu.h

@@ -113,6 +113,11 @@ class Black_hole::Gpu_session : public Session_object<Gpu::Session>
 		                        Gpu::addr_t /* va */) override
 		{ }
 
+		Gpu::addr_t query_buffer_ppgtt(Buffer_id /* id */) override
+		{
+			return (Gpu::addr_t)-1;
+		}
+
 		bool set_tiling(Buffer_id      /* id */,
 		                uint32_t const /* mode */) override
 		{