PCI/P2PDMA: Introduce pci_p2pdma_unmap_sg()

Add pci_p2pdma_unmap_sg() to the two places that call pci_p2pdma_map_sg().

This is a prep patch to introduce correct mappings for p2pdma transactions
that go through the root complex.

Link: https://lore.kernel.org/r/20190730163545.4915-10-logang@deltatee.com
Link: https://lore.kernel.org/r/20190812173048.9186-10-logang@deltatee.com
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
This commit is contained in:
Logan Gunthorpe 2019-08-12 11:30:43 -06:00 committed by Bjorn Helgaas
parent 2b9f4bb2a4
commit 7f73eac3a7
4 changed files with 38 additions and 5 deletions

View File

@ -583,8 +583,10 @@ void rdma_rw_ctx_destroy(struct rdma_rw_ctx *ctx, struct ib_qp *qp, u8 port_num,
break;
}
/* P2PDMA contexts do not need to be unmapped */
if (!is_pci_p2pdma_page(sg_page(sg)))
if (is_pci_p2pdma_page(sg_page(sg)))
pci_p2pdma_unmap_sg(qp->pd->device->dma_device, sg,
sg_cnt, dir);
else
ib_dma_unmap_sg(qp->pd->device, sg, sg_cnt, dir);
}
EXPORT_SYMBOL(rdma_rw_ctx_destroy);

View File

@ -547,8 +547,10 @@ static void nvme_unmap_data(struct nvme_dev *dev, struct request *req)
WARN_ON_ONCE(!iod->nents);
/* P2PDMA requests do not need to be unmapped */
if (!is_pci_p2pdma_page(sg_page(iod->sg)))
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));

View File

@ -800,7 +800,8 @@ EXPORT_SYMBOL_GPL(pci_p2pmem_publish);
* @dir: DMA direction
* @attrs: DMA attributes passed to dma_map_sg() (if called)
*
* Scatterlists mapped with this function should not be unmapped in any way.
* Scatterlists mapped with this function should be unmapped using
* pci_p2pdma_unmap_sg_attrs().
*
* Returns the number of SG entries mapped or 0 on error.
*/
@ -834,6 +835,21 @@ int pci_p2pdma_map_sg_attrs(struct device *dev, struct scatterlist *sg,
}
EXPORT_SYMBOL_GPL(pci_p2pdma_map_sg_attrs);
/**
* pci_p2pdma_unmap_sg - unmap a PCI peer-to-peer scatterlist that was
* mapped with pci_p2pdma_map_sg()
* @dev: device doing the DMA request
* @sg: scatter list to map
* @nents: number of elements returned by pci_p2pdma_map_sg()
* @dir: DMA direction
* @attrs: DMA attributes passed to dma_unmap_sg() (if called)
*/
void pci_p2pdma_unmap_sg_attrs(struct device *dev, struct scatterlist *sg,
int nents, enum dma_data_direction dir, unsigned long attrs)
{
}
EXPORT_SYMBOL_GPL(pci_p2pdma_unmap_sg_attrs);
/**
* pci_p2pdma_enable_store - parse a configfs/sysfs attribute store
* to enable p2pdma

View File

@ -32,6 +32,8 @@ void pci_p2pmem_free_sgl(struct pci_dev *pdev, struct scatterlist *sgl);
void pci_p2pmem_publish(struct pci_dev *pdev, bool publish);
int pci_p2pdma_map_sg_attrs(struct device *dev, struct scatterlist *sg,
int nents, enum dma_data_direction dir, unsigned long attrs);
void pci_p2pdma_unmap_sg_attrs(struct device *dev, struct scatterlist *sg,
int nents, enum dma_data_direction dir, unsigned long attrs);
int pci_p2pdma_enable_store(const char *page, struct pci_dev **p2p_dev,
bool *use_p2pdma);
ssize_t pci_p2pdma_enable_show(char *page, struct pci_dev *p2p_dev,
@ -87,6 +89,11 @@ static inline int pci_p2pdma_map_sg_attrs(struct device *dev,
{
return 0;
}
static inline void pci_p2pdma_unmap_sg_attrs(struct device *dev,
struct scatterlist *sg, int nents, enum dma_data_direction dir,
unsigned long attrs)
{
}
static inline int pci_p2pdma_enable_store(const char *page,
struct pci_dev **p2p_dev, bool *use_p2pdma)
{
@ -118,4 +125,10 @@ static inline int pci_p2pdma_map_sg(struct device *dev, struct scatterlist *sg,
return pci_p2pdma_map_sg_attrs(dev, sg, nents, dir, 0);
}
static inline void pci_p2pdma_unmap_sg(struct device *dev,
struct scatterlist *sg, int nents, enum dma_data_direction dir)
{
pci_p2pdma_unmap_sg_attrs(dev, sg, nents, dir, 0);
}
#endif /* _LINUX_PCI_P2P_H */