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  1. /*
  2.  * Copyright (c) 2007 Michal Konopa
  3.  * Copyright (c) 2007 Martin Jelen
  4.  * Copyright (c) 2007 Peter Majer
  5.  * Copyright (c) 2007 Jakub Jermar
  6.  * All rights reserved.
  7.  *
  8.  * Redistribution and use in source and binary forms, with or without
  9.  * modification, are permitted provided that the following conditions
  10.  * are met:
  11.  *
  12.  * - Redistributions of source code must retain the above copyright
  13.  *   notice, this list of conditions and the following disclaimer.
  14.  * - Redistributions in binary form must reproduce the above copyright
  15.  *   notice, this list of conditions and the following disclaimer in the
  16.  *   documentation and/or other materials provided with the distribution.
  17.  * - The name of the author may not be used to endorse or promote products
  18.  *   derived from this software without specific prior written permission.
  19.  *
  20.  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  21.  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  22.  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  23.  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  24.  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  25.  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  26.  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  27.  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  28.  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  29.  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  30.  */
  31.  
  32. /** @addtogroup rd
  33.  * @{
  34.  */
  35.  
  36. /**
  37.  * @file    rd.c
  38.  * @brief   Initial RAM disk for HelenOS.
  39.  */
  40.  
  41. #include <ipc/ipc.h>
  42. #include <ipc/services.h>
  43. #include <ipc/ns.h>
  44. #include <sysinfo.h>
  45. #include <as.h>
  46. #include <ddi.h>
  47. #include <align.h>
  48. #include <bool.h>
  49. #include <errno.h>
  50. #include <async.h>
  51. #include <align.h>
  52. #include <async.h>
  53. #include <futex.h>
  54. #include <stdio.h>
  55. #include <ipc/devmap.h>
  56. #include "rd.h"
  57.  
  58. #define NAME "rd"
  59.  
  60. /** Pointer to the ramdisk's image. */
  61. static void *rd_addr;
  62. /** Size of the ramdisk. */
  63. static size_t rd_size;
  64.  
  65. /**
  66.  * This futex protects the ramdisk's data.
  67.  * If we were to serve multiple requests (read + write or several writes)
  68.  * concurrently (i.e. from two or more threads), each read and write needs to be
  69.  * protected by this futex.
  70.  */
  71. atomic_t rd_futex = FUTEX_INITIALIZER;
  72.  
  73. /** Handle one connection to ramdisk.
  74.  *
  75.  * @param iid       Hash of the request that opened the connection.
  76.  * @param icall     Call data of the request that opened the connection.
  77.  */
  78. static void rd_connection(ipc_callid_t iid, ipc_call_t *icall)
  79. {
  80.     ipc_callid_t callid;
  81.     ipc_call_t call;
  82.     int retval;
  83.     void *fs_va = NULL;
  84.     ipcarg_t offset;
  85.  
  86.     /*
  87.      * We allocate VA for communication per connection.
  88.      * This allows us to potentionally have more clients and work
  89.      * concurrently.
  90.      */
  91.     fs_va = as_get_mappable_page(ALIGN_UP(BLOCK_SIZE, PAGE_SIZE));
  92.     if (!fs_va) {
  93.         /*
  94.          * Hang up the phone if we cannot proceed any further.
  95.          * This is the answer to the call that opened the connection.
  96.          */
  97.         ipc_answer_0(iid, EHANGUP);
  98.         return;
  99.     } else {
  100.         /*
  101.          * Answer the first IPC_M_CONNECT_ME_TO call.
  102.          * Return supported block size as ARG1.
  103.          */
  104.         ipc_answer_1(iid, EOK, BLOCK_SIZE);
  105.     }
  106.  
  107.     /*
  108.      * Now we wait for the client to send us its communication as_area.
  109.      */
  110.     size_t size;
  111.     int flags;
  112.     if (ipc_share_out_receive(&callid, &size, &flags)) {
  113.         if (size >= BLOCK_SIZE) {
  114.             /*
  115.              * The client sends an as_area that can absorb the whole
  116.              * block.
  117.              */
  118.             (void) ipc_share_out_finalize(callid, fs_va);
  119.         } else {
  120.             /*
  121.              * The client offered as_area too small.
  122.              * Close the connection.
  123.              */
  124.             ipc_answer_0(callid, EHANGUP);
  125.             return;    
  126.         }
  127.     } else {
  128.         /*
  129.          * The client doesn't speak the same protocol.
  130.          * At this point we can't handle protocol variations.
  131.          * Close the connection.
  132.          */
  133.         ipc_answer_0(callid, EHANGUP);
  134.         return;
  135.     }
  136.    
  137.     while (1) {
  138.         callid = async_get_call(&call);
  139.         switch (IPC_GET_METHOD(call)) {
  140.         case IPC_M_PHONE_HUNGUP:
  141.             /*
  142.              * The other side has hung up.
  143.              * Answer the message and exit the fibril.
  144.              */
  145.             ipc_answer_0(callid, EOK);
  146.             return;
  147.         case RD_READ_BLOCK:
  148.             offset = IPC_GET_ARG1(call);
  149.             if (offset * BLOCK_SIZE > rd_size - BLOCK_SIZE) {
  150.                 /*
  151.                  * Reading past the end of the device.
  152.                  */
  153.                 retval = ELIMIT;
  154.                 break;
  155.             }
  156.             futex_down(&rd_futex);
  157.             memcpy(fs_va, rd_addr + offset * BLOCK_SIZE, BLOCK_SIZE);
  158.             futex_up(&rd_futex);
  159.             retval = EOK;
  160.             break;
  161.         case RD_WRITE_BLOCK:
  162.             offset = IPC_GET_ARG1(call);
  163.             if (offset * BLOCK_SIZE > rd_size - BLOCK_SIZE) {
  164.                 /*
  165.                  * Writing past the end of the device.
  166.                  */
  167.                 retval = ELIMIT;
  168.                 break;
  169.             }
  170.             futex_up(&rd_futex);
  171.             memcpy(rd_addr + offset * BLOCK_SIZE, fs_va, BLOCK_SIZE);
  172.             futex_down(&rd_futex);
  173.             retval = EOK;
  174.             break;
  175.         default:
  176.             /*
  177.              * The client doesn't speak the same protocol.
  178.              * Instead of closing the connection, we just ignore
  179.              * the call. This can be useful if the client uses a
  180.              * newer version of the protocol.
  181.              */
  182.             retval = EINVAL;
  183.             break;
  184.         }
  185.         ipc_answer_0(callid, retval);
  186.     }
  187. }
  188.  
  189. static int driver_register(char *name)
  190. {
  191.     ipcarg_t retval;
  192.     aid_t req;
  193.     ipc_call_t answer;
  194.     int phone;
  195.     ipcarg_t callback_phonehash;
  196.  
  197.     phone = ipc_connect_me_to(PHONE_NS, SERVICE_DEVMAP, DEVMAP_DRIVER, 0);
  198.  
  199.     while (phone < 0) {
  200.         usleep(10000);
  201.         phone = ipc_connect_me_to(PHONE_NS, SERVICE_DEVMAP,
  202.             DEVMAP_DRIVER, 0);
  203.     }
  204.    
  205.     req = async_send_2(phone, DEVMAP_DRIVER_REGISTER, 0, 0, &answer);
  206.  
  207.     retval = ipc_data_write_start(phone, (char *) name, strlen(name) + 1);
  208.  
  209.     if (retval != EOK) {
  210.         async_wait_for(req, NULL);
  211.         return -1;
  212.     }
  213.  
  214.     async_set_client_connection(rd_connection);
  215.  
  216.     ipc_connect_to_me(phone, 0, 0, 0, &callback_phonehash);
  217.     async_wait_for(req, &retval);
  218.  
  219.     return phone;
  220. }
  221.  
  222. static int device_register(int driver_phone, char *name, int *handle)
  223. {
  224.     ipcarg_t retval;
  225.     aid_t req;
  226.     ipc_call_t answer;
  227.  
  228.     req = async_send_2(driver_phone, DEVMAP_DEVICE_REGISTER, 0, 0, &answer);
  229.  
  230.     retval = ipc_data_write_start(driver_phone, (char *) name, strlen(name) + 1);
  231.  
  232.     if (retval != EOK) {
  233.         async_wait_for(req, NULL);
  234.         return retval;
  235.     }
  236.  
  237.     async_wait_for(req, &retval);
  238.  
  239.     if (handle != NULL)
  240.         *handle = -1;
  241.    
  242.     if (EOK == retval) {
  243.         if (NULL != handle)
  244.             *handle = (int) IPC_GET_ARG1(answer);
  245.     }
  246.    
  247.     return retval;
  248. }
  249.  
  250. /** Prepare the ramdisk image for operation. */
  251. static bool rd_init(void)
  252. {
  253.     rd_size = sysinfo_value("rd.size");
  254.     void *rd_ph_addr = (void *) sysinfo_value("rd.address.physical");
  255.    
  256.     if (rd_size == 0) {
  257.         printf(NAME ": No RAM disk found\n");
  258.         return false;
  259.     }
  260.    
  261.     rd_addr = as_get_mappable_page(rd_size);
  262.    
  263.     int flags = AS_AREA_READ | AS_AREA_WRITE | AS_AREA_CACHEABLE;
  264.     int retval = physmem_map(rd_ph_addr, rd_addr,
  265.         ALIGN_UP(rd_size, PAGE_SIZE) >> PAGE_WIDTH, flags);
  266.  
  267.     if (retval < 0) {
  268.         printf(NAME ": Error mapping RAM disk\n");
  269.         return false;
  270.     }
  271.    
  272.     printf(NAME ": Found RAM disk at %p, %d bytes\n", rd_ph_addr, rd_size);
  273.    
  274.     int driver_phone = driver_register(NAME);
  275.     if (driver_phone < 0) {
  276.         printf(NAME ": Unable to register driver\n");
  277.         return false;
  278.     }
  279.    
  280.     int dev_handle;
  281.     if (EOK != device_register(driver_phone, "initrd", &dev_handle)) {
  282.         ipc_hangup(driver_phone);
  283.         printf(NAME ": Unable to register device\n");
  284.         return false;
  285.     }
  286.    
  287.     return true;
  288. }
  289.  
  290. int main(int argc, char **argv)
  291. {
  292.     printf(NAME ": HelenOS RAM disk server\n");
  293.    
  294.     if (!rd_init())
  295.         return -1;
  296.    
  297.     printf(NAME ": Accepting connections\n");
  298.     async_manager();
  299.  
  300.     /* Never reached */
  301.     return 0;
  302. }
  303.  
  304. /**
  305.  * @}
  306.  */
  307.