genode/base-fiasco/src/core/io_mem_session_support.cc

96 lines
2.5 KiB
C++

/*
* \brief Fiasco-specific implementation of the IO_MEM session interface
* \author Christian Helmuth
* \date 2006-08-28
*/
/*
* Copyright (C) 2006-2012 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.
*/
/* core includes */
#include <platform.h>
#include <util.h>
#include <io_mem_session_component.h>
/* Fiasco includes */
namespace Fiasco {
#include <l4/sys/ipc.h>
#include <l4/sigma0/sigma0.h>
}
using namespace Genode;
void Io_mem_session_component::_unmap_local(addr_t base, size_t size)
{
platform()->region_alloc()->free(reinterpret_cast<void *>(base));
}
static inline bool can_use_super_page(addr_t base, size_t size) {
return (base & (get_super_page_size() - 1)) == 0
&& (size >= get_super_page_size()); }
addr_t Io_mem_session_component::_map_local(addr_t base, size_t size)
{
using namespace Fiasco;
/* align large I/O dataspaces on a super-page boundary within core */
size_t alignment = (size >= get_super_page_size()) ? get_super_page_size_log2()
: get_page_size_log2();
/* find appropriate region for mapping */
void *local_base = 0;
if (!platform()->region_alloc()->alloc_aligned(size, &local_base, alignment))
return 0;
/* call sigma0 for I/O region */
int err;
l4_umword_t request;
l4_umword_t dw0, dw1;
l4_msgdope_t result;
l4_msgtag_t tag;
l4_threadid_t sigma0 = sigma0_threadid;
unsigned offset = 0;
while (size) {
/* FIXME what about caching demands? */
/* FIXME what about read / write? */
/* special case for page0, which is RAM in sigma0/x86 */
if (base + offset == 0)
request = SIGMA0_REQ_FPAGE_RAM;
else
request = SIGMA0_REQ_FPAGE_IOMEM;
size_t page_size_log2 = get_page_size_log2();
if (can_use_super_page(base + offset, size))
page_size_log2 = get_super_page_size_log2();
err = l4_ipc_call_tag(sigma0,
L4_IPC_SHORT_MSG,
request,
l4_fpage(base + offset, page_size_log2, 0, 0).fpage,
l4_msgtag(L4_MSGTAG_SIGMA0, 0, 0, 0),
L4_IPC_MAPMSG((addr_t)local_base + offset, page_size_log2),
&dw0, &dw1,
L4_IPC_NEVER, &result, &tag);
if (err || !l4_ipc_fpage_received(result)) {
PERR("%d %d", err, l4_ipc_fpage_received(result));
return 0;
}
offset += 1 << page_size_log2;
size -= 1 << page_size_log2;
}
return (addr_t)local_base;
}