Re: CVS commit: src/sys

[Grégoire Sutre <gregoire.sutre%gmail.com@localhost>]

On 09/01/2011 05:10 PM, Christos Zoulas wrote:
> Module Name:    src
> Committed By:   christos
> Date:           Thu Sep  1 15:10:32 UTC 2011
>
> Modified Files:
>         src/sys/arch/i386/eisa: eisa_machdep.c
>         src/sys/arch/i386/mca: mca_machdep.c
>         src/sys/arch/x86/include: bus_private.h
>         src/sys/arch/x86/isa: isa_machdep.c
>         src/sys/arch/x86/pci: pci_machdep.c
>         src/sys/arch/x86/x86: bus_dma.c
>         src/sys/arch/xen/xen: isa_machdep.c xpci_xenbus.c
>         src/sys/sys: bus.h
>
> Log Message:
> Add bus_dma overrides. From dyoung

Should NULL be allowed as first argument of bus_dma_tag_create?
I would prefer for NULL to be allowed to make my life easier in
the drmgem port from OpenBSD.  But maybe requiring non-NULL would
make more sense if this shall be used from MI device drivers only?

> +int
> +bus_dma_tag_create(bus_dma_tag_t obdt, const uint64_t present,
> +    const struct bus_dma_overrides *ov, void *ctx, bus_dma_tag_t *bdtp)
>   {
> +       uint64_t bit, bits, nbits;
> +       bus_dma_tag_t bdt;
> +       const void *fp;
>
> -       (*tag->_dmatag_destroy)(tag);
> +       if (ov == NULL || present == 0)
> +               return EINVAL;
> +
> +       bdt = kmem_alloc(sizeof(struct x86_bus_dma_tag), KM_SLEEP);
> +
> +       if (bdt == NULL)
> +               return ENOMEM;
> +
> +       bdt->bdt_super = obdt;
> +
> +       for (bits = present; bits != 0; bits = nbits) {
> +               nbits = bits&  (bits - 1);
> +               bit = nbits ^ bits;
> +               if ((fp = bit_to_function_pointer(ov, bit)) == NULL) {
> +#ifdef DEBUG
> +                       printf("%s: missing bit %" PRIx64 "\n", __func__, bit);
> +#endif
> +                       goto einval;
> +               }
> +       }
> +
> +       bdt->bdt_ov = ov;
> +       bdt->bdt_exists = obdt->bdt_exists | present;

Here obdt might be NULL.

Note: bus_space_tag_create has the same issue.

Grégoire