From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sebastian Ott Date: Wed, 12 Aug 2015 11:51:58 +0000 Subject: Re: [PATCH 16/31] s390: handle page-less SG entries Message-Id: List-Id: References: <1439363150-8661-1-git-send-email-hch@lst.de> <1439363150-8661-17-git-send-email-hch@lst.de> In-Reply-To: <1439363150-8661-17-git-send-email-hch@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Christoph Hellwig Cc: torvalds@linux-foundation.org, axboe@kernel.dk, dan.j.williams@intel.com, vgupta@synopsys.com, hskinnemoen@gmail.com, egtvedt@samfundet.no, realmz6@gmail.com, dhowells@redhat.com, monstr@monstr.eu, x86@kernel.org, dwmw2@infradead.org, alex.williamson@redhat.com, grundler@parisc-linux.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, linux-alpha@vger.kernel.org, linux-ia64@vger.kernel.org, linux-metag@vger.kernel.org, linux-mips@linux-mips.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, sparclinux@vger.kernel.org, linux-xtensa@linux-xtensa.org, linux-nvdimm@ml01.01.org, linux-media@vger.kernel.org On Wed, 12 Aug 2015, Christoph Hellwig wrote: > Use sg_phys() instead of page_to_phys(sg_page(sg)) so that we don't > require a page structure for all DMA memory. > > Signed-off-by: Christoph Hellwig Acked-by: Sebastian Ott > --- > arch/s390/pci/pci_dma.c | 20 ++++++++++++++------ > 1 file changed, 14 insertions(+), 6 deletions(-) > > diff --git a/arch/s390/pci/pci_dma.c b/arch/s390/pci/pci_dma.c > index 6fd8d58..aae5a47 100644 > --- a/arch/s390/pci/pci_dma.c > +++ b/arch/s390/pci/pci_dma.c > @@ -272,14 +272,13 @@ int dma_set_mask(struct device *dev, u64 mask) > } > EXPORT_SYMBOL_GPL(dma_set_mask); > > -static dma_addr_t s390_dma_map_pages(struct device *dev, struct page *page, > - unsigned long offset, size_t size, > +static dma_addr_t s390_dma_map_phys(struct device *dev, unsigned long pa, > + size_t size, > enum dma_data_direction direction, > struct dma_attrs *attrs) > { > struct zpci_dev *zdev = get_zdev(to_pci_dev(dev)); > unsigned long nr_pages, iommu_page_index; > - unsigned long pa = page_to_phys(page) + offset; > int flags = ZPCI_PTE_VALID; > dma_addr_t dma_addr; > > @@ -301,7 +300,7 @@ static dma_addr_t s390_dma_map_pages(struct device *dev, struct page *page, > > if (!dma_update_trans(zdev, pa, dma_addr, size, flags)) { > atomic64_add(nr_pages, &zdev->mapped_pages); > - return dma_addr + (offset & ~PAGE_MASK); > + return dma_addr + (pa & ~PAGE_MASK); > } > > out_free: > @@ -312,6 +311,16 @@ out_err: > return DMA_ERROR_CODE; > } > > +static dma_addr_t s390_dma_map_pages(struct device *dev, struct page *page, > + unsigned long offset, size_t size, > + enum dma_data_direction direction, > + struct dma_attrs *attrs) > +{ > + unsigned long pa = page_to_phys(page) + offset; > + > + return s390_dma_map_phys(dev, pa, size, direction, attrs); > +} > + > static void s390_dma_unmap_pages(struct device *dev, dma_addr_t dma_addr, > size_t size, enum dma_data_direction direction, > struct dma_attrs *attrs) > @@ -384,8 +393,7 @@ static int s390_dma_map_sg(struct device *dev, struct scatterlist *sg, > int i; > > for_each_sg(sg, s, nr_elements, i) { > - struct page *page = sg_page(s); > - s->dma_address = s390_dma_map_pages(dev, page, s->offset, > + s->dma_address = s390_dma_map_phys(dev, sg_phys(s), > s->length, dir, NULL); > if (!dma_mapping_error(dev, s->dma_address)) { > s->dma_length = s->length; > -- > 1.9.1 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ >