----- Original Message -----
>Date: Thu, 14 Feb 2008 10:13:17 +0530
>From: "Nabil Rahiman" <[EMAIL PROTECTED]>
>To: "Mark Johnson" <[EMAIL PROTECTED]>
>Cc: driver-discuss@opensolaris.org
>Subject: Re: [driver-discuss] porting device driver from Linux to
> Solaris(for Atheros Ethernet driver)
>
>
>Hi,
> Thanks for the prompt reply.
>
>On 13/02/2008, Mark Johnson <[EMAIL PROTECTED]> wrote:
>>
>>
>>
>> Nabil Rahiman wrote:
>> > Hi,
>> >
>> > I am trying to port the lnux device driver into Solaris platform.
>>
>>
>>
>> Are you aware there are usually licensing issues with
>> porting a driver from Linux to Solaris? i.e. Linux
>> drivers usually have a GPLv2 license and therefore
>> can't be included with Solaris/OpenSolaris.
>
>
> I used Linux source for getting the information how it is
>communicating with hardware(ATheros
>Ethernet chip). Because there is no specification available for this device.
> I think this is not against the license. If this is against licensing
>issue how could I get the specification for this particular hardware.
> I used the source code which is available in
>http://homepage2.nifty.com/mrym3/taiyodo/eng/
> There he used two different files one for specific to the device and other
>one is a common architecture (how the driver is communicating with OS and
>creating some data structure for its communication) for an Ethernet driver.
>And I am rewriting the file which is specific to device. I hope this is not
>the against the license agreement.
If you want to distribute the driver, I recommend to start from *bsd
driver.
>> In Solaris for allocatting dma resource, we have to set the
>> > following set of dma attributes.
>> >
>> > typedef struct ddi_dma_attr {
>> >
>> > uint_t dma_attr_version; /* version number */
>> > uint64_t dma_attr_addr_lo; /* low DMA address range
>> */
>> > uint64_t dma_attr_addr_hi; /* high DMA address
>> range */
>> >
>> > uint64_t dma_attr_count_max; /* DMA counter register
>> */
>> > uint64_t dma_attr_align; /* DMA address alignment
>> */
>> > uint_t dma_attr_burstsizes; /* DMA burstsizes */
>> >
>> > uint32_t dma_attr_minxfer; /* min effective DMA
>> size */
>> > uint64_t dma_attr_maxxfer; /* max DMA xfer size */
>> > uint64_t dma_attr_seg; /* segment boundary */
>> >
>> > int dma_attr_sgllen; /* s/g length */
>> > uint32_t dma_attr_granular; /* granularity of device
>> */
>> > uint_t dma_attr_flags; /* Bus specific DMA
>> flags */
>> >
>> > } ddi_dma_attr_t;
>> >
>> >
>> > And most of these attribute values are specific to the device.
>> >
>> > But I couldn't find out the corresponding structure/functionality in
>> Linux.
>> >
>> > Please guide me.
>>
>>
>> I'm not sure what you are asking. Could you re-word it? I made a
>> pass at what all the fields are used for.
>
There is no standard api or structure in Linux which is corresponding
to dma attribute in Solaris. You need to think them by yourself,
but it is easy. To do that, you need to notice following.
buffer address bits in tx and rx descriptors
this will define dma low and high address and align.
buffer size bits in tx and rx descriptors.
this will define dma counts
the number of descriptors you can use for one packet
this will define segment boundary ant s/g list length
-masa
>
> I think the information that you passed to the structure member
>variable is not
>be always same. It will different for the different device.
> So I need to pass the values to this structure variable which suit for
>the Atheros Device.
>
> If the values is specif to the device then there could be some similar data
>structure
>in linux also. But couldn't figure out which data structure that we want to
>use in linux. So that use
>the same here in Solaris.
>
>
>
>
>
> > uint_t dma_attr_version; /* version number */
>>
>>
>> should be set to DMA_ATTR_V0
>>
>>
>>
>> > uint64_t dma_attr_addr_lo; /* low DMA address
>> range */
>>
>>
>> the lowest physical address the device can dma to.
>> Set to 0x0.
>>
>>
>>
>> > uint64_t dma_attr_addr_hi; /* high DMA address
>> range */
>>
>>
>> The highest dma address the device can DMA to (i.e. when
>> you need to use a copy/bounce buffer). Usually set to
>> 0xFFFF.FFFF or 0xFFFF.FFFF.FFFF.FFFF
>>
>>
>>
>> > uint64_t dma_attr_count_max; /* DMA counter
>> register */
>>
>>
>> The maximum size of a single physically contiguous region (cookie)
>> you want return from ddi_dma_*_bind().
>>
>>
>>
>>
>>
>> > uint64_t dma_attr_align; /* DMA address
>> alignment */
>>
>>
>> The buffer alignment. Only use in ddi_dma_mem_alloc().
>>
>>
>>
>> > uint_t dma_attr_burstsizes; /* DMA burstsizes */
>>
>>
>> Not used. Set to 0x1.
>>
>>
>>
>> > uint32_t dma_attr_minxfer; /* min effective DMA
>> size */
>>
>>
>> Minimum xfer size. Not used on x86. Usually set to 1.
>>
>>
>>
>> > uint64_t dma_attr_maxxfer; /* max DMA xfer size
>> */
>>
>>
>> maximum size dma a device can do. usually this ==
>> (dma_attr_count_max * dma_attr_sgllen), but not always.
>> Once you exceed this, the ddi_dma_*_bind() will break
>> the bind into multiple windows (assuming you support
>> partial maps). It may also break it into multiple
>> windows if your devices needs to use a bounce buffer
>> and you exceeded the maximum size of the bounce
>> buffer.
>>
>>
>>
>> > uint64_t dma_attr_seg; /* segment boundary */
>>
>>
>> Address boundary that a device cannot DMA over. Usually
>> used on old devices and/or bus technologies. usually
>> st to 0xFFFF.FFFF
>>
>>
>>
>>
>> > int dma_attr_sgllen; /* s/g length */
>>
>>
>> The maximum number of physically contiguous regions (cookies)
>> that the device supports.
>>
>>
>>
>> > uint32_t dma_attr_granular; /* granularity of
>> device */
>>
>>
>> uses when breaking a buffer into multiple windows. The
>> windows will be broken into whole multiples of granularity.
>> commonly used in storage drivers which do DMAs in 512 byte
>> chunks. usually set to 1 or 512.
>>
>>
>>
>>
>> > uint_t dma_attr_flags; /* Bus specific DMA
>> flags */
>>
>>
>>
>> Set to 0x0.
>>
>>
>>
>>
>> MRJ
>>
>
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