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rom_loopdev: use generic block component/driver 

Ref #966
This commit is contained in:
Stefan Kalkowski 2013-11-22 23:15:47 +01:00 committed by Norman Feske
parent 0c8a4f9f3a
commit 1256b01867
1 changed files with 119 additions and 244 deletions
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363
os/src/server/rom_loopdev/main.cc
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@ -13,265 +13,140 @@
#include <base/exception.h>
#include <base/printf.h>
#include <base/sleep.h>
#include <base/semaphore.h>
#include <base/allocator_avl.h>
#include <root/component.h>
#include <os/config.h>
#include <cap_session/connection.h>
#include <rom_session/connection.h>
#include <block_session/rpc_object.h>
#include <block/component.h>
#include <block/driver.h>
using namespace Genode;
namespace Block {
class Session_component : public Session_rpc_object
{
private:
/**
* Thread handling the requests of an open block session.
*/
class Tx_thread : public Thread<8192>
{
private:
Session_component *_session; /* corresponding session object */
addr_t _dev_addr; /* rom-file address */
size_t _dev_size; /* rom-file size */
size_t _blk_size; /* block size */
public:
/**
* Constructor
*/
Tx_thread(Session_component *session,
addr_t dev_addr,
size_t dev_size,
size_t blk_size)
: Thread("block_session_tx"),
_session(session),
_dev_addr(dev_addr),
_dev_size(dev_size),
_blk_size(blk_size) { }
/**
* Thread's entry function.
*/
void entry()
{
Session_component::Tx::Sink *tx_sink =
_session->tx_sink();
Block::Packet_descriptor packet;
/* signal preparedness to server activation */
_session->tx_ready();
/* handle requests */
while (true) {
/* blocking-get packet from client */
packet = tx_sink->get_packet();
if (!packet.valid()) {
PWRN("received invalid packet");
continue;
}
/* sanity check block number */
if ((packet.block_number() + packet.block_count()
> _dev_size / _blk_size)
|| packet.block_number() < 0) {
PWRN("requested blocks %zd-%zd out of range!",
packet.block_number(),
packet.block_number() + packet.block_count());
continue;
}
size_t offset = packet.block_number() * _blk_size;
size_t size = packet.block_count() * _blk_size;
switch (packet.operation()) {
case Block::Packet_descriptor::READ:
{
/* copy file content to packet payload */
memcpy(tx_sink->packet_content(packet),
(void*)(_dev_addr + offset),
size);
packet.succeeded(true);
break;
}
case Block::Packet_descriptor::WRITE:
{
PWRN("write attempt on read-only device");
packet.succeeded(false);
break;
}
default:
PWRN("unsupported operation");
packet.succeeded(false);
continue;
}
/* acknowledge packet to the client */
if (!tx_sink->ready_to_ack())
PDBG("need to wait until ready-for-ack");
tx_sink->acknowledge_packet(packet);
}
}
friend class Session_component;
};
private:
Dataspace_capability _tx_ds; /* buffer for tx channel */
Semaphore _startup_sema; /* thread startup sync */
Tx_thread _tx_thread; /* thread handling block requests */
size_t _block_count; /* count of blocks of this session */
size_t _block_size; /* size of a block */
public:
/**
* Constructor
*
* \param tx_buf_size buffer size for tx channel
* \param dev_addr address of attached file
* \param dev_size size of attached file
*/
Session_component(size_t tx_buf_size,
addr_t dev_addr,
size_t dev_size,
size_t blk_size,
Genode::Rpc_entrypoint &ep)
: Session_rpc_object(env()->ram_session()->alloc(tx_buf_size), ep),
_startup_sema(0),
_tx_thread(this, dev_addr, dev_size, blk_size),
_block_count(dev_size / blk_size),
_block_size(blk_size)
{
_tx_thread.start();
/* block until thread is ready to handle requests */
_startup_sema.down();
}
/**
* Signal indicating that transmit thread is ready
*/
void tx_ready() { _startup_sema.up(); }
/*****************************
** Block session interface **
*****************************/
void info(size_t *blk_count, size_t *blk_size, Operations *ops)
{
*blk_count = _block_count;
*blk_size = _block_size;
ops->set_operation(Block::Packet_descriptor::READ);
}
void sync() {}
};
/**
* Root component, handling new session requests
*/
class Root : public Root_component<Session_component>
{
private:
Dataspace_capability _file_cap; /* rom-file capability */
addr_t _file_addr; /* start address of attached file */
size_t _file_sz; /* file size */
size_t _blk_sz; /* block size */
Genode::Rpc_entrypoint &_channel_ep;
protected:
Session_component *_create_session(const char *args)
{
size_t ram_quota =
Arg_string::find_arg(args, "ram_quota" ).ulong_value(0);
size_t tx_buf_size =
Arg_string::find_arg(args, "tx_buf_size").ulong_value(0);
/*
* Check if donated ram quota suffices for session data,
* and communication buffer.
*/
size_t session_size = sizeof(Session_component) + tx_buf_size;
if (max((size_t)4096, session_size) > ram_quota) {
PERR("insufficient 'ram_quota', got %zd, need %zd",
ram_quota, session_size);
throw Root::Quota_exceeded();
}
return new (md_alloc())
Session_component(tx_buf_size, _file_addr, _file_sz, _blk_sz, _channel_ep);
}
public:
/**
* Constructor
*
* \param session_ep session entrypoint
* \param md_alloc meta-data allocator
* \param file_cap capabilty of file to use as block-device
*/
Root(Rpc_entrypoint *session_ep, Allocator *md_alloc,
Dataspace_capability file_cap, size_t blk_size)
: Root_component<Session_component>(session_ep, md_alloc),
_file_cap(file_cap),
_file_addr(env()->rm_session()->attach(file_cap)),
_file_sz(Dataspace_client(file_cap).size()),
_blk_sz(blk_size),
_channel_ep(*session_ep) { }
~Root() { env()->rm_session()->detach((void*)_file_addr); }
};
}
/**
* Get name of the file we want to provide as block device,
* and the block_size.
*/
static void process_config(char *file, size_t size, size_t *blk_size)
class Rom_blk : public Block::Driver
{
try {
config()->xml_node().attribute("file").value(file, size);
config()->xml_node().attribute("block_size").value(blk_size);
private:
Rom_connection _rom;
Dataspace_capability _file_cap; /* rom-file capability */
addr_t _file_addr; /* start address of attached file */
size_t _file_sz; /* file size */
size_t _blk_sz; /* block size */
size_t _blk_cnt; /* block count */
public:
Rom_blk(const char *name, size_t blk_sz)
: _rom(name),
_file_cap(_rom.dataspace()),
_file_addr(env()->rm_session()->attach(_file_cap)),
_file_sz(Dataspace_client(_file_cap).size()),
_blk_sz(blk_sz),
_blk_cnt(_file_sz/_blk_sz) { }
/****************************
** Block-driver interface **
****************************/
Genode::size_t block_size() { return _blk_sz; }
Genode::size_t block_count() { return _blk_cnt; }
Block::Session::Operations ops()
{
Block::Session::Operations o;
o.set_operation(Block::Packet_descriptor::READ);
return o;
}
void read(Genode::size_t block_number,
Genode::size_t block_count,
char *out_buffer)
{
/* sanity check block number */
if ((block_number + block_count > _file_sz / _blk_sz)
|| block_number < 0) {
PWRN("requested blocks %zd-%zd out of range!",
block_number, block_number + block_count);
return;
}
size_t offset = block_number * _blk_sz;
size_t size = block_count * _blk_sz;
/* copy file content to packet payload */
memcpy(out_buffer, (void*)(_file_addr + offset), size);
}
void write(Genode::size_t block_number,
Genode::size_t block_count,
char const *buffer)
{
PWRN("write attempt on read-only device");
}
/*
* This driver does not support DMA operation, currently.
*/
void read_dma(Genode::size_t, Genode::size_t, Genode::addr_t) {
throw Io_error(); }
void write_dma(Genode::size_t, Genode::size_t, Genode::addr_t) {
throw Io_error(); }
bool dma_enabled() { return false; }
Genode::Ram_dataspace_capability alloc_dma_buffer(Genode::size_t size) {
return Genode::env()->ram_session()->alloc(size, false); }
void sync() {}
};
struct Factory : Block::Driver_factory
{
Block::Driver *create()
{
char file[64];
size_t blk_sz = 512;
try {
config()->xml_node().attribute("file").value(file, sizeof(file));
config()->xml_node().attribute("block_size").value(&blk_sz);
}
catch (...) { }
PINF("Using file=%s as device with block size %zx.", file, blk_sz);
try {
Rom_blk *driver = new (Genode::env()->heap()) Rom_blk(file, blk_sz);
return driver;
} catch(Rom_connection::Rom_connection_failed) {
PERR("Cannot open file %s.", file);
}
throw Root::Unavailable();
}
catch (...) { }
}
void destroy(Block::Driver *driver) {
Genode::destroy(env()->heap(), driver); }
};
int main()
{
static char file[64];
static size_t block_size = 512;
enum { STACK_SIZE = 8192 };
static Cap_connection cap;
static Rpc_entrypoint ep(&cap, STACK_SIZE, "rom_blk_ep");
process_config(file, sizeof(file), &block_size);
static Signal_receiver receiver;
static Factory driver_factory;
static Block::Root block_root(&ep, env()->heap(), driver_factory, receiver);
PINF("Using file=%s as device with block size %zx.", file, block_size);
env()->parent()->announce(ep.manage(&block_root));
try {
enum { STACK_SIZE = 8192 };
static Cap_connection cap;
static Rpc_entrypoint ep(&cap, STACK_SIZE, "rom_loop_ep");
static Rom_connection rom(file);
static Block::Root blk_root(&ep, env()->heap(), rom.dataspace(), block_size);
env()->parent()->announce(ep.manage(&blk_root));
sleep_forever();
} catch (Rom_connection::Rom_connection_failed) {
PERR("Cannot open file %s.", file);
while (true) {
Signal s = receiver.wait_for_signal();
static_cast<Signal_dispatcher_base *>(s.context())->dispatch(s.num());
}
return 0;
}