On Wed, 2008-02-06 at 18:32 -0600, Becky Bruce wrote: > > I've been looking at converting 32-bit powerpc's DMA code over to the > 64-bit method, where there is a dma_ops structure inside archdata > that tells us which operations a device should use for DMA. I'll be > needing this shortly because I need to implement swiotlb to deal with > PCI and large amounts of RAM on 32-bit systems that support 36-bit > physical addressing. (Yes, I know. Fun for me. Woohoo.) > > Anyway, I have an initial booting first pass, and wanted to get some > feedback. What I've done at this point is to make dma_64 common to both > architectures (will rename it when I send a real patch...). The > dma_direct_* functions have been changed to work on both 32/64, and the > old dma_* functionality in dma-mapping.h has been removed. For now, to > avoid whacking on every 32-bit platform, the get_dma_ops() function has > been changed to return &dma_direct_ops if the device pointer exists but > the dma_ops field is NULL. I'm not sure if this needs to be ifdef'd for > 64-bit?
I'd prefer so yes. > I've copied a bit of code over from pci_64.c into pci_common.c - some of > it isn't in use yet but will be once I start doing actual setup in the > platform code. pcibios_setup_new_device() becomes common as well. Cool ! > I've > also temporarily hacked the 32-bit code to set archdata.dma_data to > PCI_DRAM_OFFSET, so we can eliminate the use of virt_to_bus() and instead > use the 64-bit method, which gets rid of some ugly ifdefs in the dma code. Ok. > That's really about it - the preliminary patch is below - clearly it will > need some cleanup, but I wanted to post early and often. Any feedback or > suggestions on cleaning this up are greatly appreciated. I'll have a look asap, thanks for doing this ! Ben. _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev