/*
* Copyright (c) 2007 Michal Konopa
* Copyright (c) 2007 Martin Jelen
* Copyright (c) 2007 Peter Majer
* Copyright (c) 2007 Jakub Jermar
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/** @addtogroup rd
* @{
*/
/**
* @file rd.c
* @brief Initial RAM disk for HelenOS.
*/
#include <ipc/ipc.h>
#include <ipc/services.h>
#include <ipc/ns.h>
#include <sysinfo.h>
#include <as.h>
#include <ddi.h>
#include <align.h>
#include <bool.h>
#include <errno.h>
#include <async.h>
#include <align.h>
#include <async.h>
#include <futex.h>
#include "rd.h"
/** Pointer to the ramdisk's image. */
static void *rd_addr;
/** Size of the ramdisk. */
static size_t rd_size;
/**
* This futex protects the ramdisk's data.
* If we were to serve multiple requests (read + write or several writes)
* concurrently (i.e. from two or more threads), each read and write needs to be
* protected by this futex.
*/
atomic_t rd_futex = FUTEX_INITIALIZER;
/** Handle one connection to ramdisk.
*
* @param iid Hash of the request that opened the connection.
* @param icall Call data of the request that opened the connection.
*/
static void rd_connection(ipc_callid_t iid, ipc_call_t *icall)
{
ipc_callid_t callid;
ipc_call_t call;
int retval;
void *fs_va = NULL;
ipcarg_t offset;
/*
* We allocate VA for communication per connection.
* This allows us to potentionally have more clients and work
* concurrently.
*/
fs_va = as_get_mappable_page(ALIGN_UP(BLOCK_SIZE, PAGE_SIZE));
if (!fs_va) {
/*
* Hang up the phone if we cannot proceed any further.
* This is the answer to the call that opened the connection.
*/
ipc_answer_0(iid, EHANGUP);
return;
} else {
/*
* Answer the first IPC_M_CONNECT_ME_TO call.
* Return supported block size as ARG1.
*/
ipc_answer_1(iid, EOK, BLOCK_SIZE);
}
/*
* Now we wait for the client to send us its communication as_area.
*/
callid = async_get_call(&call);
if (IPC_GET_METHOD(call) == IPC_M_AS_AREA_SEND) {
if (IPC_GET_ARG1(call) >= (ipcarg_t) BLOCK_SIZE) {
/*
* The client sends an as_area that can absorb the whole
* block.
*/
ipc_answer_1(callid, EOK, (uintptr_t) fs_va);
} else {
/*
* The client offered as_area too small.
* Close the connection.
*/
ipc_answer_0(callid, EHANGUP);
return;
}
} else {
/*
* The client doesn't speak the same protocol.
* At this point we can't handle protocol variations.
* Close the connection.
*/
ipc_answer_0(callid, EHANGUP);
return;
}
while (1) {
callid = async_get_call(&call);
switch (IPC_GET_METHOD(call)) {
case IPC_M_PHONE_HUNGUP:
/*
* The other side has hung up.
* Answer the message and exit the fibril.
*/
ipc_answer_0(callid, EOK);
return;
case RD_READ_BLOCK:
offset = IPC_GET_ARG1(call);
if (offset * BLOCK_SIZE > rd_size - BLOCK_SIZE) {
/*
* Reading past the end of the device.
*/
retval = ELIMIT;
break;
}
futex_down(&rd_futex);
memcpy(fs_va
, rd_addr
+ offset
, BLOCK_SIZE
); futex_up(&rd_futex);
retval = EOK;
break;
case RD_WRITE_BLOCK:
offset = IPC_GET_ARG1(call);
if (offset * BLOCK_SIZE > rd_size - BLOCK_SIZE) {
/*
* Writing past the end of the device.
*/
retval = ELIMIT;
break;
}
futex_up(&rd_futex);
memcpy(rd_addr
+ offset
, fs_va
, BLOCK_SIZE
); futex_down(&rd_futex);
retval = EOK;
break;
default:
/*
* The client doesn't speak the same protocol.
* Instead of closing the connection, we just ignore
* the call. This can be useful if the client uses a
* newer version of the protocol.
*/
retval = EINVAL;
break;
}
ipc_answer_0(callid, retval);
}
}
/** Prepare the ramdisk image for operation. */
static bool rd_init(void)
{
int retval, flags;
rd_size = sysinfo_value("rd.size");
void *rd_ph_addr = (void *) sysinfo_value("rd.address.physical");
if (rd_size == 0)
return false;
rd_addr = as_get_mappable_page(rd_size);
flags = AS_AREA_READ | AS_AREA_WRITE | AS_AREA_CACHEABLE;
retval = physmem_map(rd_ph_addr, rd_addr,
ALIGN_UP(rd_size, PAGE_SIZE) >> PAGE_WIDTH, flags);
if (retval < 0)
return false;
return true;
}
int main(int argc, char **argv)
{
if (rd_init()) {
ipcarg_t phonead;
async_set_client_connection(rd_connection);
/* Register service at nameserver */
if (ipc_connect_to_me(PHONE_NS, SERVICE_RD, 0, &phonead) != 0)
return -1;
async_manager();
/* Never reached */
return 0;
}
return -1;
}
/**
* @}
*/