> > Then, maybe 6 month, maybe 1 year later, we can change archs that use
> > the "alternate" semantic like sparc64 to no longer fail
> > pci_set_dma_mask(64bits).
> >
> > In fact, the only breakage here would be for those archs to have some
> > drivers start going slowly, though we could expect drivers to have been
> > fixed by then.... (And we can delay that second part of the change as
> > long as deemed necessary).
>
> The arch implementations of pci_map_*() et al. might start
> failing since they were written assuming that DAC never got
> enabled.
True. However, as I said, we don't have to deprecate the old technique
right away, we have time to get the drivers fixed, provided we agree
that this is the way to go.
> > Yup, but you didn't fix sparc32 :-) I suppose I can try to do it and ask
> > Anton for help if things go wrong, though I can't be bothered building a
> > cross toolchain or getting a box on ebay so I'll rely on your for
> > testing :-)
>
> I only do sparc32 build testing, which you can do on a sparc64
> box and Al Viro has great recipies for cross tool building and
> usage.
Yup, I might have a look. (Or maybe can you give accounts on a box I can
use ? That would be even easier)
> > Thus, that is 3 pointers gone for archs who don't use these, and the ability
> > to put things like your dma ops in every struct device.
>
> How exactly does your device struct extension work? I ask because
> struct device is embedded into other structs, such as pci_dev,
> so it has to be fixed in size unless you have some clever trick. :)
Nah, my extension is fixed, it's just that it's defined by the arch. So
archs who don't care don't get the bloat.
Right now, my implementation just hijacks firmare_data, so it's a
pointer (and thus potentially could be variable size) but I want to have
it "flat" in for performances.
My current device_ext on powerpc is:
struct device_ext {
/* Optional pointer to an OF device node */
struct device_node *of_node;
/* DMA operations on that device */
struct dma_mapping_ops *dma_ops;
void *dma_data;
/* NUMA node if applicable */
int numa_node;
};
If we remove plaform_data and firmware_data from struct device, then the
size difference is one pointer and one int, which isn't -that- much (for
powerpc, I consider that acceptable).
The idea is just to have asm/device.h do
struct device_ext {
};
That is, define an empty struct, for all archs that don't care about it,
though I want to move the dma_cohrerent_map thingy into the extension
for the 3 archs that seem to use it (x86, frv and m32.
Cheers,
Ben
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
