100 lines
2.9 KiB
C++
100 lines
2.9 KiB
C++
/*
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* \brief Export RAM dataspace as shared memory object
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* \author Norman Feske
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* \date 2009-10-02
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*/
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/*
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* Copyright (C) 2009-2015 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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/* Genode includes */
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#include <base/printf.h>
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#include <base/thread.h>
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/* core includes */
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#include <ram_session_component.h>
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#include <platform.h>
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#include <util.h>
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#include <nova_util.h>
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/* NOVA includes */
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#include <nova/syscalls.h>
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using namespace Genode;
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void Ram_session_component::_revoke_ram_ds(Dataspace_component *ds) { }
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static inline void * alloc_region(Dataspace_component *ds, const size_t size)
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{
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/*
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* Allocate range in core's virtual address space
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*
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* Start with trying to use natural alignment. If this does not work,
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* successively weaken the alignment constraint until we hit the page size.
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*/
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void *virt_addr = 0;
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size_t align_log2 = log2(ds->size());
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for (; align_log2 >= get_page_size_log2(); align_log2--) {
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if (platform()->region_alloc()->alloc_aligned(size,
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&virt_addr, align_log2).is_ok())
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break;
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}
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return virt_addr;
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}
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void Ram_session_component::_clear_ds(Dataspace_component *ds)
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{
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size_t page_rounded_size = align_addr(ds->size(), get_page_size_log2());
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size_t memset_count = page_rounded_size / 4;
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addr_t memset_ptr = ds->core_local_addr();
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if ((memset_count * 4 == page_rounded_size) && !(memset_ptr & 0x3))
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asm volatile ("rep stosl" : "+D" (memset_ptr), "+c" (memset_count)
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: "a" (0) : "memory");
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else
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memset(reinterpret_cast<void *>(memset_ptr), 0, page_rounded_size);
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/* we don't keep any core-local mapping */
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unmap_local(reinterpret_cast<Nova::Utcb *>(Thread_base::myself()->utcb()),
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ds->core_local_addr(),
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page_rounded_size >> get_page_size_log2());
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platform()->region_alloc()->free((void*)ds->core_local_addr(),
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page_rounded_size);
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ds->assign_core_local_addr(nullptr);
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}
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void Ram_session_component::_export_ram_ds(Dataspace_component *ds) {
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size_t page_rounded_size = align_addr(ds->size(), get_page_size_log2());
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/* allocate the virtual region contiguous for the dataspace */
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void * virt_ptr = alloc_region(ds, page_rounded_size);
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if (!virt_ptr)
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throw Out_of_metadata();
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/* map it writeable for _clear_ds */
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Nova::Utcb * const utcb = reinterpret_cast<Nova::Utcb *>(Thread_base::myself()->utcb());
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const Nova::Rights rights_rw(true, true, false);
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if (map_local(utcb, ds->phys_addr(), reinterpret_cast<addr_t>(virt_ptr),
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page_rounded_size >> get_page_size_log2(), rights_rw, true)) {
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platform()->region_alloc()->free(virt_ptr, page_rounded_size);
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throw Out_of_metadata();
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}
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/* assign virtual address to the dataspace to be used by clear_ds */
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ds->assign_core_local_addr(virt_ptr);
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}
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