From mboxrd@z Thu Jan 1 00:00:00 1970 From: Geert Uytterhoeven Subject: [PATCH/RFC 0/4] Re: dma_mmap_coherent / ARCH_HAS_DMA_MMAP_COHERENT Date: Fri, 28 Dec 2012 20:23:30 +0100 Message-ID: <1356722614-18224-1-git-send-email-geert@linux-m68k.org> References: Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: linux-arch@vger.kernel.org, Marek Szyprowski , linux-kernel@vger.kernel.org, linux-media@vger.kernel.org Cc: linux-m68k@vger.kernel.org List-Id: linux-m68k@vger.kernel.org On Sun, Dec 16, 2012 at 5:03 PM, Geert Uytterhoeven wrote: > drivers/media/v4l2-core/videobuf2-dma-contig.c: In function =E2=80=98= vb2_dc_mmap=E2=80=99: > drivers/media/v4l2-core/videobuf2-dma-contig.c:204: error: implicit d= eclaration of function =E2=80=98dma_mmap_coherent=E2=80=99 > drivers/media/v4l2-core/videobuf2-dma-contig.c: In function =E2=80=98= vb2_dc_get_base_sgt=E2=80=99: > drivers/media/v4l2-core/videobuf2-dma-contig.c:387: error: implicit d= eclaration of function =E2=80=98dma_get_sgtable=E2=80=99 > make[6]: *** [drivers/media/v4l2-core/videobuf2-dma-contig.o] Error 1 > make[6]: Target `__build' not remade because of errors. > make[5]: *** [drivers/media/v4l2-core] Error 2 > > Both dma_mmap_coherent() and dma_get_sgtable() are defined in > include/asm-generic/dma-mapping-common.h only, which is included by > on alpha, arm, arm64, hexagon, ia64, microblaze, = mips, > openrisc, powerpc, s390, sh, sparc, tile, unicore32, x86. > Should the remaining architectures include this, too? > Should it be moved to ? I came up with an RFC-solution for this in [PATCH/RFC 3/4] ("avr32/bfin/c6x/cris/frv/m68k/mn10300/parisc/xtensa: Add dummy get_dma= _ops()") and [PATCH/RFC 4/4] ("common: dma-mapping: Move dma_common_*() to ") of this series. > Furthermore, there's ARCH_HAS_DMA_MMAP_COHERENT, which is defined > by powerpc only: > arch/powerpc/include/asm/dma-mapping.h:#define ARCH_HAS_DMA_MMAP_COHE= RENT > > and handled in some fishy way in sound/core/pcm_native.c: > > #ifndef ARCH_HAS_DMA_MMAP_COHERENT > /* This should be defined / handled globally! */ > #ifdef CONFIG_ARM > #define ARCH_HAS_DMA_MMAP_COHERENT > #endif > #endif > > /* > * mmap the DMA buffer on RAM > */ > int snd_pcm_lib_default_mmap(struct snd_pcm_substream *substream, > struct vm_area_struct *area) > { > area->vm_flags |=3D VM_DONTEXPAND | VM_DONTDUMP; > #ifdef ARCH_HAS_DMA_MMAP_COHERENT > if (!substream->ops->page && > substream->dma_buffer.dev.type =3D=3D SNDRV_DMA_TYPE_DEV) > return dma_mmap_coherent(substream->dma_buffer.dev.de= v, > area, > substream->runtime->dma_area= , > substream->runtime->dma_addr= , > area->vm_end - area->vm_star= t); > #elif defined(CONFIG_MIPS) && defined(CONFIG_DMA_NONCOHERENT) > if (substream->dma_buffer.dev.type =3D=3D SNDRV_DMA_TYPE_DEV = && > !plat_device_is_coherent(substream->dma_buffer.dev.dev)) > area->vm_page_prot =3D pgprot_noncached(area->vm_page= _prot); > #endif /* ARCH_HAS_DMA_MMAP_COHERENT */ > /* mmap with fault handler */ > area->vm_ops =3D &snd_pcm_vm_ops_data_fault; > return 0; > } > EXPORT_SYMBOL_GPL(snd_pcm_lib_default_mmap); > > What's up here? Probably an easy solution here is to kill ARCH_HAS_DMA_MMAP_COHERENT an= d change the code to #if defined(CONFIG_MIPS) && defined(CONFIG_DMA_NONCOHERENT) if (substream->dma_buffer.dev.type =3D=3D SNDRV_DMA_TYPE_DEV && !plat_device_is_coherent(substream->dma_buffer.dev.dev)) area->vm_page_prot =3D pgprot_noncached(area->vm_page_prot); #else if (!substream->ops->page && substream->dma_buffer.dev.type =3D=3D SNDRV_DMA_TYPE_DEV) return dma_mmap_coherent(substream->dma_buffer.dev.dev, area, substream->runtime->dma_area, substream->runtime->dma_addr, area->vm_end - area->vm_start); #endif but obviously I don't like the test for CONFIG_MIPS in generic code... Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-= m68k.org In personal conversations with technical people, I call myself a hacker= =2E But when I'm talking to journalists I just say "programmer" or something li= ke that. -- Linus Torvalds