Re: [PATCH -mm 00/12] adds include/asm-generic/pci-dma-common.h

[FUJITA Tomonori]

On Tue, 9 Feb 2010 16:23:35 +0100
Arnd Bergmann <arnd@xxxxxxxx> wrote:

> On Tuesday 09 February 2010, e@xxxxxxxxxxxxx wrote:
> > This patchset adds include/asm-generic/pci-dma-common.h that defines
> > the pci_unmap state API:
> > 
> > DECLARE_PCI_UNMAP_ADDR(ADDR_NAME)
> > DECLARE_PCI_UNMAP_LEN(LEN_NAME)
> > pci_unmap_addr(PTR, ADDR_NAME)
> > pci_unmap_addr_set(PTR, ADDR_NAME, VAL)
> > pci_unmap_len(PTR, LEN_NAME)
> > pci_unmap_len_set(PTR, LEN_NAME, VAL)
> > 
> > This enables us to remove lots of the duplication in architecture
> > implementations since there are only two ways to define the API.
> 
> Good stuff, moving this code to a common location is certainly
> a step in the right direction.
> 
> A few general comments though:
> 
> * It seems you left out arch/cris for no good reason.

Yeah, somehow I missed it. I'll do next time.


> * The general tendency nowadays is to avoid new HAVE_ARCH_*
>   macros and instead using either a Kconfig symbol or
>   checking the presence of the macros themselves. In this case,
>   the macro would always be present, so CONFIG_PCI_UNMAP
>   would be reasonable.

I see. I go with CONFIG_NEED_DMA_MAP_STATE (it's a bit explanatory and
mips already uses CONFIG_DMA_NEED_PCI_MAP_STATE for the same purpose).


> * AFAICT, there are no architectures left doing the
>   non-generic version, so the code could be moved to
>   a global file in include/linux instead of include/asm-generic.
>   While include/linux/pci.h is already a bit overloaded, it's
>   probably the right place for this. Alternatively,
>   include/linux/pci-dma.h, included from include/linux/pci.h.

Ok, I go with linux/pci-dma.h. I prefer linux/pci.h but as you said,
looks like already too big. We'll remove this file after moving to the
generic device model. So the name shouldn't matter much.


Thanks!
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/