device.h

/*
 * Copyright (C) 2018-2020 Kernkonzept GmbH.
 * Author(s): Sarah Hoffmann <sarah.hoffmann@kernkonzept.com>
 *
 * This file is distributed under the terms of the GNU General Public
 * License, version 2.  Please see the COPYING-GPL-2 file for details.
 */
#pragma once
 
#include <l4/cxx/ref_ptr>
#include <l4/cxx/string>
#include <l4/re/dataspace>
#include <l4/re/dma_space>
 
#include <l4/libblock-device/errand.h>
#include <l4/libblock-device/types.h>
#include <l4/libblock-device/request_queue.h>
 
namespace Block_device {
 
struct Device : public cxx::Ref_obj
{
  virtual ~Device() = 0;
 
  virtual bool is_read_only() const = 0;
  virtual bool match_hid(cxx::String const &hid) const = 0;
  virtual l4_uint64_t capacity() const = 0;
  virtual l4_size_t sector_size() const = 0;
  virtual l4_size_t max_size() const = 0;
  virtual unsigned max_segments() const = 0;
 
  virtual Request_queue *request_queue() = 0;
 
  virtual void reset() = 0;
 
  virtual int dma_map(Block_device::Mem_region *region, l4_addr_t offset,
                      l4_size_t num_sectors, L4Re::Dma_space::Direction dir,
                      L4Re::Dma_space::Dma_addr *phys) = 0;
 
  virtual int dma_unmap(L4Re::Dma_space::Dma_addr phys, l4_size_t num_sectors,
                        L4Re::Dma_space::Direction dir) = 0;
 
  virtual int inout_data(l4_uint64_t sector,
                         Block_device::Inout_block const &blocks,
                         Block_device::Inout_callback const &cb,
                         L4Re::Dma_space::Direction dir) = 0;
 
  virtual int flush(Block_device::Inout_callback const &cb) = 0;
 
  virtual void start_device_scan(Block_device::Errand::Callback const &callback) = 0;
};
 
inline Device::~Device() = default;
 
template <typename DEV>
class Device_with_request_queue : public DEV
{
public:
  Request_queue *request_queue() override
  { return &_request_queue; }
 
private:
  Simple_request_queue _request_queue;
};
 
struct Device_discard_feature
{
  struct Discard_info
  {
    unsigned max_discard_sectors = 0;
    unsigned max_discard_seg = 0;
    unsigned discard_sector_alignment = 1;
    unsigned max_write_zeroes_sectors = 0;
    unsigned max_write_zeroes_seg = 0;
    bool write_zeroes_may_unmap = false;
  };
 
  virtual Discard_info discard_info() const = 0;
 
  virtual int discard(l4_uint64_t offset,
                      Block_device::Inout_block const &blocks,
                      Block_device::Inout_callback const &cb, bool discard) = 0;
 
protected:
  ~Device_discard_feature() = default;
};
 
} // name space