On Mon, 13 Oct 2008 13:06:36 -0500 Kumar Gala <[EMAIL PROTECTED]> wrote:
> > On Oct 13, 2008, at 10:41 AM, Josh Boyer wrote: > > > On Mon, Oct 13, 2008 at 10:49:04AM -0400, Josh Boyer wrote: > >> On Fri, Sep 12, 2008 at 03:34:46PM -0500, Becky Bruce wrote: > >>> We essentially adopt the 64-bit dma code, with some changes to > >>> support > >>> 32-bit systems, including HIGHMEM. dma functions on 32-bit are now > >>> invoked via accessor functions which call the correct op for a > >>> device based > >>> on archdata dma_ops. If there is no archdata dma_ops, this defaults > >>> to dma_direct_ops. > >>> > >>> In addition, the dma_map/unmap_page functions are added to dma_ops > >>> because we can't just fall back on map/unmap_single when HIGHMEM is > >>> enabled. In the case of dma_direct_*, we stop using map/unmap_single > >>> and just use the page version - this saves a lot of ugly > >>> ifdeffing. We leave map/unmap_single in the dma_ops definition, > >>> though, because they are needed by the iommu code, which does not > >>> implement map/unmap_page. Ideally, going forward, we will > >>> completely > >>> eliminate map/unmap_single and just have map/unmap_page, if it's > >>> workable for 64-bit. > >>> > >>> Signed-off-by: Becky Bruce <[EMAIL PROTECTED]> > >> > >> While doing a buildall this morning, I notice chrp32_defconfig fails > >> to build with: > >> > >> drivers/built-in.o: In function `hard_dma_setup': > >> floppy.c:(.text+0x6e40e): undefined reference to `isa_bridge_pcidev' > >> floppy.c:(.text+0x6e412): undefined reference to `isa_bridge_pcidev' > >> floppy.c:(.text+0x6e53e): undefined reference to `isa_bridge_pcidev' > >> floppy.c:(.text+0x6e546): undefined reference to `isa_bridge_pcidev' > >> floppy.c:(.text+0x6e54a): undefined reference to `isa_bridge_pcidev' > >> make[1]: *** [.tmp_vmlinux1] Error 1 > >> > >> (the hard_dma_setup thing is in arch/powerpc/include/asm/floppy.h). > >> > >> I did a git bisect and it pointed at this commit as causing the build > >> to fail. Why, I have no idea. > > > > Ok, I was annoyed enough to look at why. > > > > Basically, before this patch pci_map_single on 32-bit PPC seemed to > > be compiled down to __dma_sync(ptr, size, direction); and the "dev" > > parameter to the function was never actually used. The compiler > > seems to have optimized this out entirely, so we don't get the odd > > link reference to isa_bridge_pcidev at all. (Neither pci_map_single > > or isa_bridge_pcidev are present in the vmlinux at all). > > > > With the patch, the compiler doesn't do this code elimination > > because pci_map_single boils down to dma_map_page, which calls > > get_dma_direct_offset with the "dev" parameter. So since it is > > still used, the compiler can't eliminate it and hence FAIL. > > > > I have no patch for this at the moment. Someone should look at > > it more closely, because this is causing the 5 chrp32_defconfig > > users to weep. > > Isn't this the type of regression we should fix post -rc1 :) I don't think it matters much when it gets fixed, pre or post -rc1. But it should probably get fixed. My hack was to pull isa_bridge_pcidev into pci-common.c and export it from there. The 64-bit PCI code can initialized it, and the 32-bit can leave it NULL. But I have no idea if that is sane. If so, I can probably submit a patch for it. josh _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
