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    Subjectshould struct device.dma_mask still be a pointer?
    Hello,

    IMHO it's strange that struct device.dma_mask is a pointer instead of a
    plain u64. The reason this was done back then is described in
    8ab1bc19e974fdebe76c065fe444979c84ba2f74[1]:

    Attached is a patch which moves dma_mask into struct device and cleans up the
    scsi mid-layer to use it (instead of using struct pci_dev). The advantage to
    doing this is probably most apparent on non-pci bus architectures where
    currently you have to construct a fake pci_dev just so you can get the bounce
    buffers to work correctly.

    The patch tries to perturb the minimum amount of code, so dma_mask in struct
    device is simply a pointer to the one in pci_dev. However, it will make it
    easy for me now to add generic device to MCA without having to go the fake pci
    route.

    As I work on such a non-pci bus architecture it's still ugly that this
    is a pointer because I have to allocate extra memory for that.

    Is there a reason not to get rid of struct pci_dev.dma_mask and use
    struct pci_dev.dev.dma_mask instead? (Well apart from the needed
    effort of course.)

    If not, the following would be needed:

    - remove struct pci.dma_mask
    - make struct device.dma_mask an u64 (instead of u64*)
    - substitue var.dma_mask by var.dev.dma_mask for all
    struct pci_dev var
    - substitue var.dma_mask by &(var.dma_mask) for all
    struct device var

    and note that there are statically initialized struct device (and maybe
    struct pci_dev?) that need fixing, too. (e.g.
    http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=blob;f=arch/arm/mach-mx2/devices.c;h=a0aeb8a4adc19ef419a0a045ad3b882131597106;hb=HEAD#l265
    )

    Additionally this could be done for struct device.dma_parms.

    Julia: help!

    Best regards
    Uwe

    [1] as this is pre-2.6.12 it's only available in tglx' histroy tree,
    e.g. http://git.kernel.org/?p=linux/kernel/git/tglx/history.git;a=commitdiff;h=8ab1bc19e974fdebe76c065fe444979c84ba2f74

    --
    Pengutronix e.K. | Uwe Kleine-König |
    Industrial Linux Solutions | http://www.pengutronix.de/ |
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