LXR linux/drivers/scsi/arm/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#include <linux/scatterlist.h>
  14
  15#define BELT_AND_BRACES
  16
  17/*
  18 * The scatter-gather list handling.  This contains all
  19 * the yucky stuff that needs to be fixed properly.
  20 */
  21static inline int copy_SCp_to_sg(struct scatterlist *sg, struct scsi_pointer *SCp, int max)
  22{
  23        int bufs = SCp->buffers_residual;
  24
  25        BUG_ON(bufs + 1 > max);
  26
  27        sg_set_buf(sg, SCp->ptr, SCp->this_residual);
  28
  29        if (bufs)
  30                memcpy(sg + 1, SCp->buffer + 1,
  31                       sizeof(struct scatterlist) * bufs);
  32        return bufs + 1;
  33}
  34
  35static inline int next_SCp(struct scsi_pointer *SCp)
  36{
  37        int ret = SCp->buffers_residual;
  38        if (ret) {
  39                SCp->buffer++;
  40                SCp->buffers_residual--;
  41                SCp->ptr = sg_virt(SCp->buffer);
  42                SCp->this_residual = SCp->buffer->length;
  43        } else {
  44                SCp->ptr = NULL;
  45                SCp->this_residual = 0;
  46        }
  47        return ret;
  48}
  49
  50static inline unsigned char get_next_SCp_byte(struct scsi_pointer *SCp)
  51{
  52        char c = *SCp->ptr;
  53
  54        SCp->ptr += 1;
  55        SCp->this_residual -= 1;
  56
  57        return c;
  58}
  59
  60static inline void put_next_SCp_byte(struct scsi_pointer *SCp, unsigned char c)
  61{
  62        *SCp->ptr = c;
  63        SCp->ptr += 1;
  64        SCp->this_residual -= 1;
  65}
  66
  67static inline void init_SCp(struct scsi_cmnd *SCpnt)
  68{
  69        memset(&SCpnt->SCp, 0, sizeof(struct scsi_pointer));
  70
  71        if (SCpnt->use_sg) {
  72                unsigned long len = 0;
  73                int buf;
  74
  75                SCpnt->SCp.buffer = (struct scatterlist *) SCpnt->request_buffer;
  76                SCpnt->SCp.buffers_residual = SCpnt->use_sg - 1;
  77                SCpnt->SCp.ptr = sg_virt(SCpnt->SCp.buffer);
  78                SCpnt->SCp.this_residual = SCpnt->SCp.buffer->length;
  79                SCpnt->SCp.phase = SCpnt->request_bufflen;
  80
  81#ifdef BELT_AND_BRACES
  82                /*
  83                 * Calculate correct buffer length.  Some commands
  84                 * come in with the wrong request_bufflen.
  85                 */
  86                for (buf = 0; buf <= SCpnt->SCp.buffers_residual; buf++)
  87                        len += SCpnt->SCp.buffer[buf].length;
  88
  89                if (SCpnt->request_bufflen != len)
  90                        printk(KERN_WARNING "scsi%d.%c: bad request buffer "
  91                               "length %d, should be %ld\n", SCpnt->device->host->host_no,
  92                               '0' + SCpnt->device->id, SCpnt->request_bufflen, len);
  93                SCpnt->request_bufflen = len;
  94#endif
  95        } else {
  96                SCpnt->SCp.ptr = (unsigned char *)SCpnt->request_buffer;
  97                SCpnt->SCp.this_residual = SCpnt->request_bufflen;
  98                SCpnt->SCp.phase = SCpnt->request_bufflen;
  99        }
 100
 101        /*
 102         * If the upper SCSI layers pass a buffer, but zero length,
 103         * we aren't interested in the buffer pointer.
 104         */
 105        if (SCpnt->SCp.this_residual == 0 && SCpnt->SCp.ptr) {
 106#if 0 //def BELT_AND_BRACES
 107                printk(KERN_WARNING "scsi%d.%c: zero length buffer passed for "
 108                       "command ", SCpnt->host->host_no, '0' + SCpnt->target);
 109                __scsi_print_command(SCpnt->cmnd);
 110#endif
 111                SCpnt->SCp.ptr = NULL;
 112        }
 113}
 114