288fd4e56e
This patch extends the RAM session interface with the ability to allocate DMA buffers. The client specifies the type of RAM dataspace to allocate via the new 'cached' argument of the 'Ram_session::alloc()' function. By default, 'cached' is true, which correponds to the common case and the original behavior. When setting 'cached' to 'false', core takes the precautions needed to register the memory as uncached in the page table of each process that has the dataspace attached. Currently, the support for allocating DMA buffers is implemented for Fiasco.OC only. On x86 platforms, it is generally not needed. But on platforms with more relaxed cache coherence (such as ARM), user-level device drivers should always use uncacheable memory for DMA transactions.
25 lines
594 B
C++
25 lines
594 B
C++
/*
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* \brief Fiasco-specific part of RM-session implementation
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* \author Stefan Kalkowski
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* \date 2011-01-18
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*/
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/*
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* Copyright (C) 2011-2012 Genode Labs GmbH
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*
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* This file is part of the Genode OS framework, which is distributed
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* under the terms of the GNU General Public License version 2.
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*/
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/* core includes */
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#include <rm_session_component.h>
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#include <map_local.h>
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using namespace Genode;
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void Rm_client::unmap(addr_t core_local_base, addr_t virt_base, size_t size)
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{
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// TODO unmap it only from target space
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unmap_local(core_local_base, size >> get_page_size_log2());
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}
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