genode/repos/base/include/base/attached_io_mem_dataspace.h

91 lines
2.4 KiB
C++

/*
* \brief I/O MEM dataspace utility
* \author Norman Feske
* \date 2011-05-19
*/
/*
* Copyright (C) 2011-2017 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.
*/
#ifndef _INCLUDE__BASE__ATTACHED_IO_MEM_DATASPACE_H_
#define _INCLUDE__BASE__ATTACHED_IO_MEM_DATASPACE_H_
#include <io_mem_session/connection.h>
#include <base/env.h>
namespace Genode { class Attached_io_mem_dataspace; }
/**
* Request and locally attach a memory-mapped I/O resource
*
* This class is a wrapper for a typical sequence of operations performed
* by device drivers to access memory-mapped device resources. Its sole
* purpose is to avoid duplicated code.
*/
class Genode::Attached_io_mem_dataspace
{
private:
Region_map &_env_rm;
Io_mem_connection _mmio;
Io_mem_dataspace_capability _ds;
Region_map::Local_addr _local_addr;
static void *_with_sub_page_offset(void *local, addr_t io_base)
{
return (void *)((addr_t)local | (io_base & (addr_t)0xfff));
}
public:
/**
* Constructor
*
* \param base base address of memory-mapped I/O resource
* \param size size of resource
* \param write_combined enable write combining for the resource
*
* \throw Service_denied
* \throw Insufficient_ram_quota
* \throw Insufficient_cap_quota
* \throw Out_of_ram
* \throw Out_of_caps
* \throw Region_map::Region_conflict
* \throw Region_map::Invalid_dataspace
*/
Attached_io_mem_dataspace(Env &env, Genode::addr_t base, Genode::size_t size,
bool write_combined = false)
:
_env_rm(env.rm()),
_mmio(env, base, size, write_combined),
_ds(_mmio.dataspace()),
_local_addr(_with_sub_page_offset(env.rm().attach(_ds), base))
{ }
/**
* Destructor
*/
~Attached_io_mem_dataspace() { _env_rm.detach(_local_addr); }
/**
* Return capability of the used RAM dataspace
*/
Io_mem_dataspace_capability cap() { return _ds; }
/**
* Request local address
*
* This is a template to avoid inconvenient casts at the caller.
* A newly allocated I/O MEM dataspace is untyped memory anyway.
*/
template <typename T>
T *local_addr() { return static_cast<T *>(_local_addr); }
};
#endif /* _INCLUDE__BASE__ATTACHED_IO_MEM_DATASPACE_H_ */