svn commit: r209026 - in head/sys/ia64: ia64 include

Marcel Moolenaar xcllnt at mac.com
Fri Jun 11 17:44:59 UTC 2010


On Jun 11, 2010, at 10:37 AM, Scott Long wrote:
> 
> I'm not clear why you even need bounce buffers for RX.  The chip supports 64bit addresses with no boundary or alignment restrictions.

As per:
        /*
         * All controllers that are not 5755 or higher have 4GB
         * boundary DMA bug.
         * Whenever an address crosses a multiple of the 4GB boundary
         * (including 4GB, 8Gb, 12Gb, etc.) and makes the transition
         * from 0xX_FFFF_FFFF to 0x(X+1)_0000_0000 an internal DMA
         * state machine will lockup and cause the device to hang.
         */
        if (BGE_IS_5755_PLUS(sc) == 0)
                sc->bge_flags |= BGE_FLAG_4G_BNDRY_BUG;

and:
        lowaddr = BUS_SPACE_MAXADDR;
        if ((sc->bge_flags & BGE_FLAG_40BIT_BUG) != 0)
                lowaddr = BGE_DMA_MAXADDR;
        if ((sc->bge_flags & BGE_FLAG_4G_BNDRY_BUG) != 0)
                lowaddr = BUS_SPACE_MAXADDR_32BIT;
        /*
         * Allocate the parent bus DMA tag appropriate for PCI.
         */
        error = bus_dma_tag_create(bus_get_dma_tag(sc->bge_dev),
            1, 0, lowaddr, BUS_SPACE_MAXADDR, NULL,
            NULL, BUS_SPACE_MAXSIZE_32BIT, 0, BUS_SPACE_MAXSIZE_32BIT,
            0, NULL, NULL, &sc->bge_cdata.bge_parent_tag);

-- 
Marcel Moolenaar
xcllnt at mac.com





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