genode/repos/base-sel4/src/core/core_region_map.cc
Norman Feske 6b289a1423 base/core: use references instead of pointers
This patch replaces the former prominent use of pointers by references
wherever feasible. This has the following benefits:

* The contract between caller and callee becomes more obvious. When
  passing a reference, the contract says that the argument cannot be
  a null pointer. The caller is responsible to ensure that. Therefore,
  the use of reference eliminates the need to add defensive null-pointer
  checks at the callee site, which sometimes merely exist to be on the
  safe side. The bottom line is that the code becomes easier to follow.

* Reference members must be initialized via an object initializer,
  which promotes a programming style that avoids intermediate object-
  construction states. Within core, there are still a few pointers
  as member variables left though. E.g., caused by the late association
  of 'Platform_thread' objects with their 'Platform_pd' objects.

* If no pointers are present as member variables, we don't need to
  manually provide declarations of a private copy constructor and
  an assignment operator to avoid -Weffc++ errors "class ... has
  pointer data members [-Werror=effc++]".

This patch also changes a few system bindings on NOVA and Fiasco.OC,
e.g., the return value of the global 'cap_map' accessor has become a
reference. Hence, the patch touches a few places outside of core.

Fixes #3135
2019-02-12 10:33:13 +01:00

79 lines
2.0 KiB
C++

/*
* \brief Core-local region map
* \author Norman Feske
* \date 2015-05-01
*/
/*
* Copyright (C) 2015-2017 Genode Labs GmbH
*
* This file is part of the Genode OS framework, which is distributed
* under the terms of the GNU Affero General Public License version 3.
*/
/* Genode includes */
#include <base/log.h>
/* core includes */
#include <core_region_map.h>
#include <platform.h>
#include <map_local.h>
using namespace Genode;
Region_map::Local_addr
Core_region_map::attach(Dataspace_capability ds_cap, size_t size, off_t offset,
bool use_local_addr, Region_map::Local_addr, bool, bool)
{
auto lambda = [&] (Dataspace_component *ds) -> Local_addr {
if (!ds)
throw Invalid_dataspace();
if (size == 0)
size = ds->size();
size_t page_rounded_size = (size + get_page_size() - 1) & get_page_mask();
if (use_local_addr) {
error(__func__, ": 'use_local_addr' not supported within core");
return nullptr;
}
if (offset) {
error(__func__, ": 'offset' not supported within core");
return nullptr;
}
/* allocate range in core's virtual address space */
void *virt_addr;
if (!platform().region_alloc().alloc(page_rounded_size, &virt_addr)) {
error("could not allocate virtual address range in core of size ",
page_rounded_size);
return nullptr;
}
/* map the dataspace's physical pages to core-local virtual addresses */
size_t num_pages = page_rounded_size >> get_page_size_log2();
map_local(ds->phys_addr(), (addr_t)virt_addr, num_pages);
return virt_addr;
};
return _ep.apply(ds_cap, lambda);
}
void Core_region_map::detach(Local_addr core_local_addr)
{
size_t size = platform_specific().region_alloc_size_at(core_local_addr);
if (!unmap_local(core_local_addr, size >> get_page_size_log2())) {
Genode::error("could not unmap core virtual address ",
Hex(core_local_addr), " in ", __PRETTY_FUNCTION__);
return;
}
platform().region_alloc().free(core_local_addr);
}