| Message ID | 20210408170123.8788-14-logang@deltatee.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Add new DMA mapping operation for P2PDMA | expand |
On 4/8/21 10:01 AM, Logan Gunthorpe wrote: > Convert to using dma_map_sg_p2pdma() for PCI p2pdma pages. > > This should be equivalent but allows for heterogeneous scatterlists > with both P2PDMA and regular pages. However, P2PDMA support will be > slightly more restricted (only dma-direct and dma-iommu are currently > supported). > > Signed-off-by: Logan Gunthorpe <logang@deltatee.com> > --- > drivers/nvme/host/pci.c | 28 ++++++++-------------------- > 1 file changed, 8 insertions(+), 20 deletions(-) > > diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c > index 14f092973792..a1ed07ff38b7 100644 > --- a/drivers/nvme/host/pci.c > +++ b/drivers/nvme/host/pci.c > @@ -577,17 +577,6 @@ static void nvme_free_sgls(struct nvme_dev *dev, struct request *req) > > } > > -static void nvme_unmap_sg(struct nvme_dev *dev, struct request *req) > -{ > - struct nvme_iod *iod = blk_mq_rq_to_pdu(req); > - > - if (is_pci_p2pdma_page(sg_page(iod->sg))) > - pci_p2pdma_unmap_sg(dev->dev, iod->sg, iod->nents, > - rq_dma_dir(req)); > - else > - dma_unmap_sg(dev->dev, iod->sg, iod->nents, rq_dma_dir(req)); > -} > - > static void nvme_unmap_data(struct nvme_dev *dev, struct request *req) > { > struct nvme_iod *iod = blk_mq_rq_to_pdu(req); > @@ -600,7 +589,7 @@ static void nvme_unmap_data(struct nvme_dev *dev, struct request *req) > > WARN_ON_ONCE(!iod->nents); > > - nvme_unmap_sg(dev, req); > + dma_unmap_sg(dev->dev, iod->sg, iod->nents, rq_dma_dir(req)); Nice simplification! > if (iod->npages == 0) > dma_pool_free(dev->prp_small_pool, nvme_pci_iod_list(req)[0], > iod->first_dma); > @@ -868,14 +857,13 @@ static blk_status_t nvme_map_data(struct nvme_dev *dev, struct request *req, > if (!iod->nents) > goto out_free_sg; > > - if (is_pci_p2pdma_page(sg_page(iod->sg))) > - nr_mapped = pci_p2pdma_map_sg_attrs(dev->dev, iod->sg, > - iod->nents, rq_dma_dir(req), DMA_ATTR_NO_WARN); > - else > - nr_mapped = dma_map_sg_attrs(dev->dev, iod->sg, iod->nents, > - rq_dma_dir(req), DMA_ATTR_NO_WARN); > - if (!nr_mapped) > + nr_mapped = dma_map_sg_p2pdma_attrs(dev->dev, iod->sg, iod->nents, > + rq_dma_dir(req), DMA_ATTR_NO_WARN); > + if (nr_mapped < 0) { > + if (nr_mapped != -ENOMEM) > + ret = BLK_STS_TARGET; > goto out_free_sg; > + } But now the "nr_mapped == 0" case is no longer doing an early out_free_sg. Is that OK? > > iod->use_sgl = nvme_pci_use_sgls(dev, req); > if (iod->use_sgl) > @@ -887,7 +875,7 @@ static blk_status_t nvme_map_data(struct nvme_dev *dev, struct request *req, > return BLK_STS_OK; > > out_unmap_sg: > - nvme_unmap_sg(dev, req); > + dma_unmap_sg(dev->dev, iod->sg, iod->nents, rq_dma_dir(req)); > out_free_sg: > mempool_free(iod->sg, dev->iod_mempool); > return ret; > thanks,
On 2021-05-02 7:34 p.m., John Hubbard wrote: >> if (iod->npages == 0) >> dma_pool_free(dev->prp_small_pool, nvme_pci_iod_list(req)[0], >> iod->first_dma); >> @@ -868,14 +857,13 @@ static blk_status_t nvme_map_data(struct nvme_dev *dev, struct request *req, >> if (!iod->nents) >> goto out_free_sg; >> >> - if (is_pci_p2pdma_page(sg_page(iod->sg))) >> - nr_mapped = pci_p2pdma_map_sg_attrs(dev->dev, iod->sg, >> - iod->nents, rq_dma_dir(req), DMA_ATTR_NO_WARN); >> - else >> - nr_mapped = dma_map_sg_attrs(dev->dev, iod->sg, iod->nents, >> - rq_dma_dir(req), DMA_ATTR_NO_WARN); >> - if (!nr_mapped) >> + nr_mapped = dma_map_sg_p2pdma_attrs(dev->dev, iod->sg, iod->nents, >> + rq_dma_dir(req), DMA_ATTR_NO_WARN); >> + if (nr_mapped < 0) { >> + if (nr_mapped != -ENOMEM) >> + ret = BLK_STS_TARGET; >> goto out_free_sg; >> + } > > But now the "nr_mapped == 0" case is no longer doing an early out_free_sg. > Is that OK? dma_map_sg_p2pdma_attrs() never returns zero. It will return -ENOMEM in the same situation and results in the same goto out_free_sg. Logan
On 5/3/21 10:19 AM, Logan Gunthorpe wrote: ... >>> + nr_mapped = dma_map_sg_p2pdma_attrs(dev->dev, iod->sg, iod->nents, >>> + rq_dma_dir(req), DMA_ATTR_NO_WARN); >>> + if (nr_mapped < 0) { >>> + if (nr_mapped != -ENOMEM) >>> + ret = BLK_STS_TARGET; >>> goto out_free_sg; >>> + } >> >> But now the "nr_mapped == 0" case is no longer doing an early out_free_sg. >> Is that OK? > > dma_map_sg_p2pdma_attrs() never returns zero. It will return -ENOMEM in > the same situation and results in the same goto out_free_sg. > OK...that's true, it doesn't return zero. A comment or WARN or something might be nice, to show that the zero case hasn't been overlooked. It's true that the dma_map_sg_p2pdma_attrs() documentation sort of says that (although not quite out loud). thanks,
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c index 14f092973792..a1ed07ff38b7 100644 --- a/drivers/nvme/host/pci.c +++ b/drivers/nvme/host/pci.c @@ -577,17 +577,6 @@ static void nvme_free_sgls(struct nvme_dev *dev, struct request *req) } -static void nvme_unmap_sg(struct nvme_dev *dev, struct request *req) -{ - struct nvme_iod *iod = blk_mq_rq_to_pdu(req); - - if (is_pci_p2pdma_page(sg_page(iod->sg))) - pci_p2pdma_unmap_sg(dev->dev, iod->sg, iod->nents, - rq_dma_dir(req)); - else - dma_unmap_sg(dev->dev, iod->sg, iod->nents, rq_dma_dir(req)); -} - static void nvme_unmap_data(struct nvme_dev *dev, struct request *req) { struct nvme_iod *iod = blk_mq_rq_to_pdu(req); @@ -600,7 +589,7 @@ static void nvme_unmap_data(struct nvme_dev *dev, struct request *req) WARN_ON_ONCE(!iod->nents); - nvme_unmap_sg(dev, req); + dma_unmap_sg(dev->dev, iod->sg, iod->nents, rq_dma_dir(req)); if (iod->npages == 0) dma_pool_free(dev->prp_small_pool, nvme_pci_iod_list(req)[0], iod->first_dma); @@ -868,14 +857,13 @@ static blk_status_t nvme_map_data(struct nvme_dev *dev, struct request *req, if (!iod->nents) goto out_free_sg; - if (is_pci_p2pdma_page(sg_page(iod->sg))) - nr_mapped = pci_p2pdma_map_sg_attrs(dev->dev, iod->sg, - iod->nents, rq_dma_dir(req), DMA_ATTR_NO_WARN); - else - nr_mapped = dma_map_sg_attrs(dev->dev, iod->sg, iod->nents, - rq_dma_dir(req), DMA_ATTR_NO_WARN); - if (!nr_mapped) + nr_mapped = dma_map_sg_p2pdma_attrs(dev->dev, iod->sg, iod->nents, + rq_dma_dir(req), DMA_ATTR_NO_WARN); + if (nr_mapped < 0) { + if (nr_mapped != -ENOMEM) + ret = BLK_STS_TARGET; goto out_free_sg; + } iod->use_sgl = nvme_pci_use_sgls(dev, req); if (iod->use_sgl) @@ -887,7 +875,7 @@ static blk_status_t nvme_map_data(struct nvme_dev *dev, struct request *req, return BLK_STS_OK; out_unmap_sg: - nvme_unmap_sg(dev, req); + dma_unmap_sg(dev->dev, iod->sg, iod->nents, rq_dma_dir(req)); out_free_sg: mempool_free(iod->sg, dev->iod_mempool); return ret;
Convert to using dma_map_sg_p2pdma() for PCI p2pdma pages. This should be equivalent but allows for heterogeneous scatterlists with both P2PDMA and regular pages. However, P2PDMA support will be slightly more restricted (only dma-direct and dma-iommu are currently supported). Signed-off-by: Logan Gunthorpe <logang@deltatee.com> --- drivers/nvme/host/pci.c | 28 ++++++++-------------------- 1 file changed, 8 insertions(+), 20 deletions(-)