drivers/acorn/scsi/scsi.h

   1 /*
   2  *  linux/drivers/acorn/scsi/scsi.h
   3  *
   4  *  Copyright (C) 2002 Russell King
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  *
  10  *  Commonly used scsi driver functions.
  11  */
  12
  13 #define BELT_AND_BRACES
  14
  15 /*
  16  * The scatter-gather list handling.  This contains all
  17  * the yucky stuff that needs to be fixed properly.
  18  */
  19 static inline int copy_SCp_to_sg(struct scatterlist *sg, Scsi_Pointer *SCp, int max)
  20 {
  21         int bufs = SCp->buffers_residual;
  22
  23         BUG_ON(bufs + 1 > max);
  24
  25         sg->address = SCp->ptr;
  26         sg->length = SCp->this_residual;
  27
  28         if (bufs)
  29                 memcpy(sg + 1, SCp->buffer + 1,
  30                        sizeof(struct scatterlist) * bufs);
  31         return bufs + 1;
  32 }
  33
  34 static inline int next_SCp(Scsi_Pointer *SCp)
  35 {
  36         int ret = SCp->buffers_residual;
  37         if (ret) {
  38                 SCp->buffer++;
  39                 SCp->buffers_residual--;
  40                 SCp->ptr = (unsigned char *)SCp->buffer->address;
  41                 SCp->this_residual = SCp->buffer->length;
  42         } else {
  43                 SCp->ptr = NULL;
  44                 SCp->this_residual = 0;
  45         }
  46         return ret;
  47 }
  48
  49 static inline unsigned char get_next_SCp_byte(Scsi_Pointer *SCp)
  50 {
  51         char c = *SCp->ptr;
  52
  53         SCp->ptr += 1;
  54         SCp->this_residual -= 1;
  55
  56         return c;
  57 }
  58
  59 static inline void put_next_SCp_byte(Scsi_Pointer *SCp, unsigned char c)
  60 {
  61         *SCp->ptr = c;
  62         SCp->ptr += 1;
  63         SCp->this_residual -= 1;
  64 }
  65
  66 static inline void init_SCp(Scsi_Cmnd *SCpnt)
  67 {
  68         memset(&SCpnt->SCp, 0, sizeof(struct scsi_pointer));
  69
  70         if (SCpnt->use_sg) {
  71                 unsigned long len = 0;
  72                 int buf;
  73
  74                 SCpnt->SCp.buffer = (struct scatterlist *) SCpnt->buffer;
  75                 SCpnt->SCp.buffers_residual = SCpnt->use_sg - 1;
  76                 SCpnt->SCp.ptr = (char *) SCpnt->SCp.buffer->address;
  77                 SCpnt->SCp.this_residual = SCpnt->SCp.buffer->length;
  78
  79 #ifdef BELT_AND_BRACES
  80                 /*
  81                  * Calculate correct buffer length.  Some commands
  82                  * come in with the wrong request_bufflen.
  83                  */
  84                 for (buf = 0; buf <= SCpnt->SCp.buffers_residual; buf++)
  85                         len += SCpnt->SCp.buffer[buf].length;
  86
  87                 if (SCpnt->request_bufflen != len)
  88                         printk(KERN_WARNING "scsi%d.%c: bad request buffer "
  89                                "length %d, should be %ld\n", SCpnt->host->host_no,
  90                                '0' + SCpnt->target, SCpnt->request_bufflen, len);
  91                 SCpnt->request_bufflen = len;
  92 #endif
  93         } else {
  94                 SCpnt->SCp.ptr = (unsigned char *)SCpnt->request_buffer;
  95                 SCpnt->SCp.this_residual = SCpnt->request_bufflen;
  96         }
  97
  98         /*
  99          * If the upper SCSI layers pass a buffer, but zero length,
 100          * we aren't interested in the buffer pointer.
 101          */
 102         if (SCpnt->SCp.this_residual == 0 && SCpnt->SCp.ptr) {
 103 #if 0 //def BELT_AND_BRACES
 104                 printk(KERN_WARNING "scsi%d.%c: zero length buffer passed for "
 105                        "command ", SCpnt->host->host_no, '0' + SCpnt->target);
 106                 print_command(SCpnt->cmnd);
 107 #endif
 108                 SCpnt->SCp.ptr = NULL;
 109         }
 110 }
 111
 112 static inline struct Scsi_Host *scsi_host_hn_get(int host_no)
 113 {
 114         struct Scsi_Host *host = scsi_hostlist;
 115
 116         while (host) {
 117                 if (host->host_no == host_no)
 118                         break;
 119                 host = host->next;
 120         }
 121
 122         return host;
 123 }