src/add-ons/kernel/bus_managers/scsi/ccb.cpp

   1 /*
   2 ** Copyright 2002/03, Thomas Kurschel. All rights reserved.
   3 ** Distributed under the terms of the OpenBeOS License.
   4 */
   5
   6 /*
   7         Part of Open SCSI bus manager
   8
   9         CCB manager
  10
  11         As allocation of ccb can be on the paging path we must use a
  12         locked pool.
  13 */
  14
  15 #include "scsi_internal.h"
  16
  17
  18
  19 // ccb are relatively large, so don't make it too small to not waste memory
  20 #define CCB_CHUNK_SIZE 16*1024
  21
  22 // maximum number of CCBs - probably, we want to make that editable
  23 // it must be at least 1 for normal use and 1 for stand-by autosense request
  24 #define CCB_NUM_MAX 128
  25
  26
  27 scsi_ccb *
  28 scsi_alloc_ccb(scsi_device_info *device)
  29 {
  30         scsi_ccb *ccb;
  31
  32         SHOW_FLOW0( 3, "" );
  33
  34         ccb = (scsi_ccb *)locked_pool->alloc(device->bus->ccb_pool);
  35         ccb->state = SCSI_STATE_FINISHED;
  36         ccb->device = device;
  37         ccb->target_id = device->target_id;
  38         ccb->target_lun = device->target_lun;
  39
  40         // reset some very important fields
  41         // TODO: should we better omit that to find bugs easier?
  42         ccb->sg_list = NULL;
  43         ccb->io_operation = NULL;
  44         ccb->sort = -1;
  45
  46         SHOW_FLOW(3, "path=%d", ccb->path_id);
  47
  48         return ccb;
  49 }
  50
  51
  52 void
  53 scsi_free_ccb(scsi_ccb *ccb)
  54 {
  55         SHOW_FLOW0( 3, "" );
  56
  57         if (ccb->state != SCSI_STATE_FINISHED)
  58                 panic("Tried to free ccb that's still in use (state %d)\n", ccb->state);
  59
  60         ccb->state = SCSI_STATE_FREE;
  61
  62         locked_pool->free(ccb->bus->ccb_pool, ccb);
  63 }
  64
  65
  66 static status_t
  67 ccb_low_alloc_hook(void *block, void *arg)
  68 {
  69         scsi_ccb *ccb = (scsi_ccb *)block;
  70         scsi_bus_info *bus = (scsi_bus_info *)arg;
  71         status_t res;
  72
  73         ccb->bus = bus;
  74         ccb->path_id = bus->path_id;
  75         ccb->state = SCSI_STATE_FREE;
  76
  77         if ((res = ccb->completion_sem = create_sem(0, "ccb_sem")) < 0)
  78                 return res;
  79
  80         return B_OK;
  81 }
  82
  83
  84 static void
  85 ccb_low_free_hook(void *block, void *arg)
  86 {
  87         scsi_ccb *ccb = (scsi_ccb *)block;
  88
  89         delete_sem(ccb->completion_sem);
  90 }
  91
  92
  93 status_t
  94 scsi_init_ccb_alloc(scsi_bus_info *bus)
  95 {
  96         // initially, we want no CCB allocated as the path_id of
  97         // the bus is not ready yet so the CCB cannot be initialized
  98         // correctly
  99         bus->ccb_pool = locked_pool->create(sizeof(scsi_ccb), sizeof(uint32) - 1, 0,
 100                 CCB_CHUNK_SIZE, CCB_NUM_MAX, 0, "scsi_ccb_pool", B_CONTIGUOUS,
 101                 ccb_low_alloc_hook, ccb_low_free_hook, bus);
 102
 103         if (bus->ccb_pool == NULL)
 104                 return B_NO_MEMORY;
 105
 106         return B_OK;
 107 }
 108
 109
 110 void
 111 scsi_uninit_ccb_alloc(scsi_bus_info *bus)
 112 {
 113         locked_pool->destroy(bus->ccb_pool);
 114 }
 115