' bus_dmamap_load_mbuf_sg ( ) ' function usage problem

[tanniru.sankar at wipro.com]

Hi,
 
   I am facing a problem on FreeBSD 7.0 during mapping using '
bus_dmamap_load_mbuf_sg ( ) ' function .
   Details are below.
 
   It is AMD 64 bit machine. I have allocated jumbo buffer memory using
' m_getcl ' function.
 
       mp = m_getjcl(M_DONTWAIT, MT_DATA, M_PKTHDR,  MJUM9BYTES);
 
    As it got success here, I am trying to map the buffer as below.
        
       err = bus_dmamap_load_mbuf_sg(dma_tag_rx, map, mp, &seg, &cnt,
BUS_DMA_NOWAIT);
        
      Here it is getting error for the mbuf size equal to  MJUM9BYTES.
The type of error is ' EFBIG  '.
   
    I have create  rx jumbo dma tag with attributes as following.
 
    bus_dma_tag_create(

        NULL,                               /* Parent  */

        PAGE_SIZE,                    /* Alignment */               
        0,                                    /* Bounds  */

        BUS_SPACE_MAXADDR, /* Low Address  */                  
        BUS_SPACE_MAXADDR, /* High Address   */               
        NULL,                     /* Filter Function           */

        NULL,                     /* Filter Function Arguments */

        MJUM9BYTES,       /* Maximum Size              */

        1 ,                           /* Number of Segments        */

        MJUM9BYTES,       /* Maximum Segment Size      */

        BUS_DMA_ALLOCNOW,  /* Flags                     */

        NULL,              /* Lock Function             */

        NULL,              /* Lock Function Arguments   */

        dma_tag_rx)     /* DMA Tag                   */

    I have seen the myri10ge and mxge source code, they are allocating
maximum buffer size as MJUMPAGESIZE.
    is it like this is the maximum size we can dmamap??
 
      could anyone  help me on this.
 
 
Thanks,
Sankar.
 
 
 
   
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
              

       Siva Sankar . T
           Project Engineer

      Wipro Technologies

         No.53/1 Hosur Road, 
         Madivala,
         Bangalore- 560 068. India
         Tel:+91-80-25502001 Extn.5056 
         Mobile:9886894429 
         tanniru.sankar at wipro.com
         www.wipro.com

 



The information contained in this electronic message and any attachments to this message are intended for the exclusive use of the addressee(s) and may contain proprietary, confidential or privileged information. If you are not the intended recipient, you should not disseminate, distribute or copy this e-mail. Please notify the sender immediately and destroy all copies of this message and any attachments. 

WARNING: Computer viruses can be transmitted via email. The recipient should check this email and any attachments for the presence of viruses. The company accepts no liability for any damage caused by any virus transmitted by this email.
 
www.wipro.com