From: Logan Gunthorpe <logang@deltatee.com>
To: linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org,
linux-block@vger.kernel.org, linux-pci@vger.kernel.org,
linux-mm@kvack.org, iommu@lists.linux-foundation.org
Cc: "Stephen Bates" <sbates@raithlin.com>,
"Christoph Hellwig" <hch@lst.de>,
"Dan Williams" <dan.j.williams@intel.com>,
"Jason Gunthorpe" <jgg@ziepe.ca>,
"Christian König" <christian.koenig@amd.com>,
"Ira Weiny" <iweiny@intel.com>,
"John Hubbard" <jhubbard@nvidia.com>,
"Don Dutile" <ddutile@redhat.com>,
"Matthew Wilcox" <willy@infradead.org>,
"Daniel Vetter" <daniel.vetter@ffwll.ch>,
"Jakowski Andrzej" <andrzej.jakowski@intel.com>,
"Minturn Dave B" <dave.b.minturn@intel.com>,
"Jason Ekstrand" <jason@jlekstrand.net>,
"Dave Hansen" <dave.hansen@linux.intel.com>,
"Xiong Jianxin" <jianxin.xiong@intel.com>,
"Logan Gunthorpe" <logang@deltatee.com>
Subject: [RFC PATCH v2 04/11] PCI/P2PDMA: Introduce pci_p2pdma_should_map_bus() and pci_p2pdma_bus_offset()
Date: Thu, 11 Mar 2021 16:31:34 -0700 [thread overview]
Message-ID: <20210311233142.7900-5-logang@deltatee.com> (raw)
In-Reply-To: <20210311233142.7900-1-logang@deltatee.com>
Introduce pci_p2pdma_should_map_bus() which is meant to be called by
DMA map functions to determine how to map a given p2pdma page.
pci_p2pdma_bus_offset() is also added to allow callers to get the bus
offset if they need to map the bus address.
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
---
drivers/pci/p2pdma.c | 50 ++++++++++++++++++++++++++++++++++++++
include/linux/pci-p2pdma.h | 11 +++++++++
2 files changed, 61 insertions(+)
diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c
index 7f6836732bce..66d16b7eb668 100644
--- a/drivers/pci/p2pdma.c
+++ b/drivers/pci/p2pdma.c
@@ -912,6 +912,56 @@ void pci_p2pdma_unmap_sg_attrs(struct device *dev, struct scatterlist *sg,
}
EXPORT_SYMBOL_GPL(pci_p2pdma_unmap_sg_attrs);
+/**
+ * pci_p2pdma_bus_offset - returns the bus offset for a given page
+ * @page: page to get the offset for
+ *
+ * Must be passed a PCI p2pdma page.
+ */
+u64 pci_p2pdma_bus_offset(struct page *page)
+{
+ struct pci_p2pdma_pagemap *p2p_pgmap = to_p2p_pgmap(page->pgmap);
+
+ WARN_ON(!is_pci_p2pdma_page(page));
+
+ return p2p_pgmap->bus_offset;
+}
+EXPORT_SYMBOL_GPL(pci_p2pdma_bus_offset);
+
+/**
+ * pci_p2pdma_dma_map_type - determine if a DMA mapping should use the
+ * bus address, be mapped normally or fail
+ * @dev: device doing the DMA request
+ * @pgmap: dev_pagemap structure for the mapping
+ *
+ * Returns:
+ * 1 - if the page should be mapped with a bus address,
+ * 0 - if the page should be mapped normally through an IOMMU mapping or
+ * physical address; or
+ * -1 - if the device should not map the pages and an error should be
+ * returned
+ */
+int pci_p2pdma_dma_map_type(struct device *dev, struct dev_pagemap *pgmap)
+{
+ struct pci_p2pdma_pagemap *p2p_pgmap = to_p2p_pgmap(pgmap);
+ struct pci_dev *client;
+
+ if (!dev_is_pci(dev))
+ return -1;
+
+ client = to_pci_dev(dev);
+
+ switch (pci_p2pdma_map_type(p2p_pgmap->provider, client)) {
+ case PCI_P2PDMA_MAP_THRU_HOST_BRIDGE:
+ return 0;
+ case PCI_P2PDMA_MAP_BUS_ADDR:
+ return 1;
+ default:
+ return -1;
+ }
+}
+EXPORT_SYMBOL_GPL(pci_p2pdma_dma_map_type);
+
/**
* pci_p2pdma_enable_store - parse a configfs/sysfs attribute store
* to enable p2pdma
diff --git a/include/linux/pci-p2pdma.h b/include/linux/pci-p2pdma.h
index 8318a97c9c61..3d55ad19f54c 100644
--- a/include/linux/pci-p2pdma.h
+++ b/include/linux/pci-p2pdma.h
@@ -34,6 +34,8 @@ 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);
+u64 pci_p2pdma_bus_offset(struct page *page);
+int pci_p2pdma_dma_map_type(struct device *dev, struct dev_pagemap *pgmap);
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,
@@ -83,6 +85,15 @@ static inline void pci_p2pmem_free_sgl(struct pci_dev *pdev,
static inline void pci_p2pmem_publish(struct pci_dev *pdev, bool publish)
{
}
+static inline u64 pci_p2pdma_bus_offset(struct page *page)
+{
+ return -1;
+}
+static inline int pci_p2pdma_dma_map_type(struct device *dev,
+ struct dev_pagemap *pgmap)
+{
+ return -1;
+}
static inline int pci_p2pdma_map_sg_attrs(struct device *dev,
struct scatterlist *sg, int nents, enum dma_data_direction dir,
unsigned long attrs)
--
2.20.1
next prev parent reply other threads:[~2021-03-11 23:32 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-11 23:31 [RFC PATCH v2 00/11] Add support to dma_map_sg for P2PDMA Logan Gunthorpe
2021-03-11 23:31 ` [RFC PATCH v2 01/11] PCI/P2PDMA: Pass gfp_mask flags to upstream_bridge_distance_warn() Logan Gunthorpe
2021-03-12 20:39 ` Bjorn Helgaas
2021-03-12 20:53 ` Logan Gunthorpe
2021-03-11 23:31 ` [RFC PATCH v2 02/11] PCI/P2PDMA: Avoid pci_get_slot() which sleeps Logan Gunthorpe
2021-03-12 20:57 ` Bjorn Helgaas
2021-03-12 21:37 ` Logan Gunthorpe
2021-03-11 23:31 ` [RFC PATCH v2 03/11] PCI/P2PDMA: Attempt to set map_type if it has not been set Logan Gunthorpe
2021-03-11 23:31 ` Logan Gunthorpe [this message]
2021-03-13 1:38 ` [RFC PATCH v2 04/11] PCI/P2PDMA: Introduce pci_p2pdma_should_map_bus() and pci_p2pdma_bus_offset() Ira Weiny
2021-03-15 16:27 ` Logan Gunthorpe
2021-03-24 17:21 ` Jason Gunthorpe
2021-03-24 18:34 ` Christian König
2021-03-13 2:32 ` Ira Weiny
2021-03-15 16:30 ` Logan Gunthorpe
2021-03-16 8:14 ` Christoph Hellwig
2021-03-11 23:31 ` [RFC PATCH v2 05/11] lib/scatterlist: Add flag for indicating P2PDMA segments in an SGL Logan Gunthorpe
2021-03-11 23:31 ` [RFC PATCH v2 06/11] dma-direct: Support PCI P2PDMA pages in dma-direct map_sg Logan Gunthorpe
2021-03-12 15:52 ` Robin Murphy
2021-03-12 16:24 ` Logan Gunthorpe
2021-03-12 18:11 ` Robin Murphy
2021-03-12 18:27 ` Logan Gunthorpe
2021-03-16 7:58 ` Christoph Hellwig
2021-03-16 15:54 ` Logan Gunthorpe
2021-03-16 7:56 ` Christoph Hellwig
2021-03-16 8:11 ` Christoph Hellwig
2021-03-11 23:31 ` [RFC PATCH v2 07/11] dma-mapping: Add flags to dma_map_ops to indicate PCI P2PDMA support Logan Gunthorpe
2021-03-13 2:36 ` Ira Weiny
2021-03-15 16:33 ` Logan Gunthorpe
2021-03-16 8:00 ` Christoph Hellwig
2021-03-16 8:15 ` Christoph Hellwig
2021-03-11 23:31 ` [RFC PATCH v2 08/11] iommu/dma: Support PCI P2PDMA pages in dma-iommu map_sg Logan Gunthorpe
2021-03-12 15:52 ` Robin Murphy
2021-03-12 17:03 ` Logan Gunthorpe
2021-03-12 19:47 ` Robin Murphy
2021-03-12 20:06 ` Logan Gunthorpe
2021-03-11 23:31 ` [RFC PATCH v2 09/11] block: Add BLK_STS_P2PDMA Logan Gunthorpe
2021-03-16 8:00 ` Christoph Hellwig
2021-03-16 16:02 ` Logan Gunthorpe
2021-03-11 23:31 ` [RFC PATCH v2 10/11] nvme-pci: Check DMA ops when indicating support for PCI P2PDMA Logan Gunthorpe
2021-03-11 23:31 ` [RFC PATCH v2 11/11] nvme-pci: Convert to using dma_map_sg for p2pdma pages Logan Gunthorpe
2021-03-11 23:59 ` Jason Gunthorpe
2021-03-12 1:37 ` Logan Gunthorpe
2021-03-12 15:51 ` [RFC PATCH v2 00/11] Add support to dma_map_sg for P2PDMA Robin Murphy
2021-03-12 16:18 ` Logan Gunthorpe
2021-03-12 17:46 ` Robin Murphy
2021-03-12 18:24 ` Logan Gunthorpe
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