From: Leon Romanovsky <[email protected]> Exporters keep the &struct p2pdma_provider in their own private data and hand it to dma_buf_phys_vec_to_sgt() on every map. An importer cannot reach it, so it has no way to learn how its own peer-to-peer traffic would be routed before it programs its hardware.
Publish the provider through &struct dma_buf_export_info instead, and add dma_buf_p2pdma_map_type() for importers to query it by TLP class. It is fixed at export time, so dma_buf_phys_vec_to_sgt() no longer needs it as an argument and the two exporters no longer need a copy of it. Signed-off-by: Leon Romanovsky <[email protected]> --- drivers/dma-buf/dma-buf-mapping.c | 41 +++++++++++++++++++---- drivers/dma-buf/dma-buf.c | 1 + drivers/infiniband/core/uverbs.h | 1 - drivers/infiniband/core/uverbs_std_types_dmabuf.c | 7 ++-- drivers/vfio/pci/vfio_pci_dmabuf.c | 8 ++--- include/linux/dma-buf-mapping.h | 4 ++- include/linux/dma-buf.h | 5 +++ 7 files changed, 49 insertions(+), 18 deletions(-) diff --git a/drivers/dma-buf/dma-buf-mapping.c b/drivers/dma-buf/dma-buf-mapping.c index 794acff2546a..8b431000e906 100644 --- a/drivers/dma-buf/dma-buf-mapping.c +++ b/drivers/dma-buf/dma-buf-mapping.c @@ -6,6 +6,32 @@ #include <linux/dma-buf-mapping.h> #include <linux/dma-resv.h> +/** + * dma_buf_p2pdma_map_type - How peer-to-peer traffic to a buffer is routed + * @attach: attachment of the importer that will issue the traffic + * @tlp_flags: &enum pci_p2pdma_tlp_flags describing the TLPs it will issue + * + * Reports how the PCIe fabric routes @tlp_flags traffic between the buffer + * behind @attach and the importer attached to it, so that an importer can + * choose the TLP attributes that earn it a direct route before it programs + * its hardware. + * + * Return: the mapping type for @tlp_flags traffic, or PCI_P2PDMA_MAP_NONE + * when the exporter named no &struct p2pdma_provider and nothing is known + * about the route. + */ +enum pci_p2pdma_map_type +dma_buf_p2pdma_map_type(struct dma_buf_attachment *attach, + unsigned int tlp_flags) +{ + if (!attach->dmabuf->provider) + return PCI_P2PDMA_MAP_NONE; + + return pci_p2pdma_map_type_tlp(attach->dmabuf->provider, attach->dev, + tlp_flags); +} +EXPORT_SYMBOL_NS_GPL(dma_buf_p2pdma_map_type, "DMA_BUF"); + static struct scatterlist *fill_sg_entry(struct scatterlist *sgl, size_t length, dma_addr_t addr) { @@ -71,7 +97,6 @@ struct dma_buf_dma { * from arrays of physical vectors. This funciton is intended for MMIO memory * only. * @attach: [in] attachment whose scatterlist is to be returned - * @provider: [in] p2pdma provider * @phys_vec: [in] array of physical vectors * @nr_ranges: [in] number of entries in phys_vec array * @size: [in] total size of phys_vec @@ -85,16 +110,17 @@ struct dma_buf_dma { * * A mapping must be unmapped by using dma_buf_free_sgt(). * - * NOTE: This function is intended for exporters. If direct traffic routing is - * mandatory exporter should call routing pci_p2pdma_map_type() before calling - * this function. + * NOTE: This function is intended for exporters, and works on MMIO memory + * only, so &dma_buf.provider must have been set at export time. If direct + * traffic routing is mandatory the exporter should call + * pci_p2pdma_map_type() before calling this function. */ struct sg_table *dma_buf_phys_vec_to_sgt(struct dma_buf_attachment *attach, - struct p2pdma_provider *provider, struct phys_vec *phys_vec, size_t nr_ranges, size_t size, enum dma_data_direction dir) { + struct p2pdma_provider *provider; unsigned int nents, mapped_len = 0; struct dma_buf_dma *dma; struct scatterlist *sgl; @@ -104,10 +130,11 @@ struct sg_table *dma_buf_phys_vec_to_sgt(struct dma_buf_attachment *attach, dma_resv_assert_held(attach->dmabuf->resv); - if (WARN_ON(!attach || !attach->dmabuf || !provider)) - /* This function is supposed to work on MMIO memory only */ + if (WARN_ON(!attach || !attach->dmabuf || !attach->dmabuf->provider)) return ERR_PTR(-EINVAL); + provider = attach->dmabuf->provider; + dma = kzalloc_obj(*dma); if (!dma) return ERR_PTR(-ENOMEM); diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index d504c636dc29..c2b9944e9659 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -747,6 +747,7 @@ struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info) dmabuf->size = exp_info->size; dmabuf->exp_name = exp_info->exp_name; dmabuf->owner = exp_info->owner; + dmabuf->provider = exp_info->provider; spin_lock_init(&dmabuf->name_lock); init_waitqueue_head(&dmabuf->poll); dmabuf->cb_in.poll = dmabuf->cb_out.poll = &dmabuf->poll; diff --git a/drivers/infiniband/core/uverbs.h b/drivers/infiniband/core/uverbs.h index c64dd6b94e10..fbdac18b69ca 100644 --- a/drivers/infiniband/core/uverbs.h +++ b/drivers/infiniband/core/uverbs.h @@ -139,7 +139,6 @@ struct ib_uverbs_dmabuf_file { struct list_head dmabufs_elm; struct rdma_user_mmap_entry *mmap_entry; struct phys_vec phys_vec; - struct p2pdma_provider *provider; struct kref kref; struct completion comp; u8 revoked :1; diff --git a/drivers/infiniband/core/uverbs_std_types_dmabuf.c b/drivers/infiniband/core/uverbs_std_types_dmabuf.c index 2411ebee69e2..94d3719a34da 100644 --- a/drivers/infiniband/core/uverbs_std_types_dmabuf.c +++ b/drivers/infiniband/core/uverbs_std_types_dmabuf.c @@ -33,9 +33,8 @@ uverbs_dmabuf_map(struct dma_buf_attachment *attachment, if (priv->revoked) return ERR_PTR(-ENODEV); - ret = dma_buf_phys_vec_to_sgt(attachment, priv->provider, - &priv->phys_vec, 1, priv->phys_vec.len, - dir); + ret = dma_buf_phys_vec_to_sgt(attachment, &priv->phys_vec, 1, + priv->phys_vec.len, dir); if (IS_ERR(ret)) return ret; @@ -108,7 +107,7 @@ static int UVERBS_HANDLER(UVERBS_METHOD_DMABUF_ALLOC)( return -EINVAL; ret = ib_dev->ops.mmap_get_pfns(mmap_entry, &uverbs_dmabuf->phys_vec, - &uverbs_dmabuf->provider); + &exp_info.provider); if (ret) goto err; diff --git a/drivers/vfio/pci/vfio_pci_dmabuf.c b/drivers/vfio/pci/vfio_pci_dmabuf.c index c16f460c01d6..10f47992e7f5 100644 --- a/drivers/vfio/pci/vfio_pci_dmabuf.c +++ b/drivers/vfio/pci/vfio_pci_dmabuf.c @@ -15,7 +15,6 @@ struct vfio_pci_dma_buf { struct list_head dmabufs_elm; size_t size; struct phys_vec *phys_vec; - struct p2pdma_provider *provider; u32 nr_ranges; struct kref kref; struct completion comp; @@ -59,9 +58,8 @@ vfio_pci_dma_buf_map(struct dma_buf_attachment *attachment, if (priv->revoked) return ERR_PTR(-ENODEV); - ret = dma_buf_phys_vec_to_sgt(attachment, priv->provider, - priv->phys_vec, priv->nr_ranges, - priv->size, dir); + ret = dma_buf_phys_vec_to_sgt(attachment, priv->phys_vec, + priv->nr_ranges, priv->size, dir); if (IS_ERR(ret)) return ret; @@ -274,7 +272,7 @@ int vfio_pci_core_feature_dma_buf(struct vfio_pci_core_device *vdev, u32 flags, priv->vdev = vdev; priv->nr_ranges = get_dma_buf.nr_ranges; priv->size = length; - ret = vdev->pci_ops->get_dmabuf_phys(vdev, &priv->provider, + ret = vdev->pci_ops->get_dmabuf_phys(vdev, &exp_info.provider, get_dma_buf.region_index, priv->phys_vec, dma_ranges, priv->nr_ranges); diff --git a/include/linux/dma-buf-mapping.h b/include/linux/dma-buf-mapping.h index 09bde3f748e4..d63ac4d52aa5 100644 --- a/include/linux/dma-buf-mapping.h +++ b/include/linux/dma-buf-mapping.h @@ -7,8 +7,10 @@ #define __DMA_BUF_MAPPING_H__ #include <linux/dma-buf.h> +enum pci_p2pdma_map_type +dma_buf_p2pdma_map_type(struct dma_buf_attachment *attach, + unsigned int tlp_flags); struct sg_table *dma_buf_phys_vec_to_sgt(struct dma_buf_attachment *attach, - struct p2pdma_provider *provider, struct phys_vec *phys_vec, size_t nr_ranges, size_t size, enum dma_data_direction dir); diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h index d1203da56fc5..81c136fcee6e 100644 --- a/include/linux/dma-buf.h +++ b/include/linux/dma-buf.h @@ -368,6 +368,9 @@ struct dma_buf { /** @priv: exporter specific private data for this buffer object. */ void *priv; + /** @provider: The peer-to-peer provider backing this buffer. */ + struct p2pdma_provider *provider; + /** * @resv: * @@ -501,6 +504,7 @@ struct dma_buf_attachment { * @flags: mode flags for the file * @resv: reservation-object, NULL to allocate default one * @priv: Attach private data of allocator to this buffer + * @provider: Peer-to-peer provider backing the buffer * * This structure holds the information required to export the buffer. Used * with dma_buf_export() only. @@ -512,6 +516,7 @@ struct dma_buf_export_info { size_t size; int flags; struct dma_resv *resv; + struct p2pdma_provider *provider; void *priv; }; -- 2.55.0
