genode/base-hw/src/core/ram_session_support.cc
Stefan Kalkowski 73eb7a8d4b hw: map core on demand (fix #723)
Instead of mapping all physical memory 1:1 into core/kernel's address space,
this commit limits the 1:1 mapping to the binary image, and I/O memory
regions used by the kernel only. All subsequent memory accesses of core
are done by mapping the corresponding memory on demand, and not necessarily
1:1.

This commit has several side effects:

The page table code had to be revisited completely. The kernel inserts no
longer anything into the page tables, apart from the initial translations
to have the core/kernel image available when enabling the MMU. The page
tables and higher level translation tables are no longer named Tlb, but
Translation_table instead. There is no indirection class required to define
the translation tables of a concrete SoC, the appropriated ARM specifier
is sufficient.
The ability to map core's memory the same way like it's done for all other
protection domains, makes a special treatment of core's threads (no context
area) obsolete.

Ref #567 (partly solves it)
Fix #723
Fix #1068
2014-05-07 10:37:39 +02:00

65 lines
1.9 KiB
C++

/*
* \brief Export RAM dataspace as shared memory object (dummy)
* \author Martin Stein
* \author Stefan Kalkowski
* \date 2012-02-12
*
* TODO: this file is almost identical to
* base-okl4/src/core/ram_session_support.cc, we should merge them
*/
/*
* Copyright (C) 2012-2013 Genode Labs GmbH
*
* This file is part of the Genode OS framework, which is distributed
* under the terms of the GNU General Public License version 2.
*/
/* Genode includes */
#include <base/printf.h>
/* core includes */
#include <ram_session_component.h>
#include <platform.h>
#include <map_local.h>
using namespace Genode;
void Ram_session_component::_export_ram_ds(Dataspace_component *ds) { }
void Ram_session_component::_revoke_ram_ds(Dataspace_component *ds) { }
void Ram_session_component::_clear_ds (Dataspace_component * ds)
{
size_t page_rounded_size = (ds->size() + get_page_size() - 1) & get_page_mask();
/* allocate range in core's virtual address space */
void *virt_addr;
if (!platform()->region_alloc()->alloc(page_rounded_size, &virt_addr)) {
PERR("could not allocate virtual address range in core of size %zd\n",
page_rounded_size);
return;
}
/* map the dataspace's physical pages to corresponding virtual addresses */
size_t num_pages = page_rounded_size >> get_page_size_log2();
if (!map_local(ds->phys_addr(), (addr_t)virt_addr, num_pages)) {
PERR("core-local memory mapping failed");
return;
}
/* clear dataspace */
memset(virt_addr, 0, page_rounded_size);
/* uncached dataspaces need to be flushed */
if (ds->write_combined())
Kernel::update_data_region((addr_t)virt_addr, page_rounded_size);
/* unmap dataspace from core */
if (!unmap_local((addr_t)virt_addr, num_pages))
PERR("could not unmap core-local address range at %p", virt_addr);
/* free core's virtual address space */
platform()->region_alloc()->free(virt_addr, page_rounded_size);
}