Files
genode/dde_linux/src/drivers/usb/dma.h
2012-06-22 11:50:13 +02:00

95 lines
1.9 KiB
C++

/*
* \brief DMA memory pool
* \author Sebastian Sumpf
* \date 2012-06-18
*/
/*
* Copyright (C) 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.
*/
#ifndef _DMA_H_
#define _DMA_H_
#include <base/allocator_avl.h>
#include <dataspace/client.h>
#include <lx_emul.h>
/*********************
** linux/dmapool.h **
*********************/
namespace Genode {
/**
* Dma-pool manager
*/
class Dma
{
private:
enum { SIZE = 1024 * 1024 };
addr_t _base; /* virt base of pool */
addr_t _base_phys; /* phys base of pool */
Allocator_avl _range; /* range allocator for pool */
Dma() : _range(env()->heap())
{
Ram_dataspace_capability cap = env()->ram_session()->alloc(SIZE, false);
_base_phys = Dataspace_client(cap).phys_addr();
_base = (addr_t)env()->rm_session()->attach(cap);
dde_kit_log(DEBUG_DMA, "New DMA range [%lx-%lx)", _base, _base + SIZE);
_range.add_range(_base, SIZE);
}
public:
static Dma* pool()
{
static Dma _p;
return &_p;
}
addr_t base() const { return _base; };
addr_t end() const { return _base + SIZE -1; }
/**
* Alloc 'size' bytes of DMA memory
*/
void *alloc(size_t size, int align = 12)
{
void *addr;
if (!_range.alloc_aligned(size, &addr, align)) {
PERR("DMA of %zu bytes allocation failed", size);
return 0;
}
return addr;
}
/**
* Free DMA memory
*/
void free(void *addr) { _range.free(addr); }
/**
* Get phys for virt address
*/
addr_t phys_addr(void *addr)
{
addr_t a = (addr_t)addr;
if (a < _base || a >= _base + SIZE) {
PERR("No DMA phys addr for %lx", a);
return 0;
}
return (a - _base) + _base_phys;
}
};
}
#endif /* _DMA_H_ */