4 files changed, 119 insertions, 0 deletions
diff --git a/include/linux/memremap.h b/include/linux/memremap.h
index f91f9e763557..9553370ebdad 100644
--- a/include/linux/memremap.h
+++ b/include/linux/memremap.h
@@ -53,11 +53,16 @@ struct vmem_altmap {
  * wakeup event whenever a page is unpinned and becomes idle. This
  * wakeup is used to coordinate physical address space management (ex:
  * fs truncate/hole punch) vs pinned pages (ex: device dma).
+ *
+ * MEMORY_DEVICE_PCI_P2PDMA:
+ * Device memory residing in a PCI BAR intended for use with Peer-to-Peer
+ * transactions.
  */
 enum memory_type {
 	MEMORY_DEVICE_PRIVATE = 1,
 	MEMORY_DEVICE_PUBLIC,
 	MEMORY_DEVICE_FS_DAX,
+	MEMORY_DEVICE_PCI_P2PDMA,
 };
 
 /*
diff --git a/include/linux/mm.h b/include/linux/mm.h
index a61ebe8ad4ca..2055df412a77 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -890,6 +890,19 @@ static inline bool is_device_public_page(const struct page *page)
 		page->pgmap->type == MEMORY_DEVICE_PUBLIC;
 }
 
+#ifdef CONFIG_PCI_P2PDMA
+static inline bool is_pci_p2pdma_page(const struct page *page)
+{
+	return is_zone_device_page(page) &&
+		page->pgmap->type == MEMORY_DEVICE_PCI_P2PDMA;
+}
+#else /* CONFIG_PCI_P2PDMA */
+static inline bool is_pci_p2pdma_page(const struct page *page)
+{
+	return false;
+}
+#endif /* CONFIG_PCI_P2PDMA */
+
 #else /* CONFIG_DEV_PAGEMAP_OPS */
 static inline void dev_pagemap_get_ops(void)
 {
@@ -913,6 +926,11 @@ static inline bool is_device_public_page(const struct page *page)
 {
 	return false;
 }
+
+static inline bool is_pci_p2pdma_page(const struct page *page)
+{
+	return false;
+}
 #endif /* CONFIG_DEV_PAGEMAP_OPS */
 
 static inline void get_page(struct page *page)
diff --git a/include/linux/pci-p2pdma.h b/include/linux/pci-p2pdma.h
new file mode 100644
index 000000000000..7bdaacfd5892
--- /dev/null
+++ b/include/linux/pci-p2pdma.h
@@ -0,0 +1,92 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * PCI Peer 2 Peer DMA support.
+ *
+ * Copyright (c) 2016-2018, Logan Gunthorpe
+ * Copyright (c) 2016-2017, Microsemi Corporation
+ * Copyright (c) 2017, Christoph Hellwig
+ * Copyright (c) 2018, Eideticom Inc.
+ */
+
+#ifndef _LINUX_PCI_P2PDMA_H
+#define _LINUX_PCI_P2PDMA_H
+
+#include <linux/pci.h>
+
+struct block_device;
+struct scatterlist;
+
+#ifdef CONFIG_PCI_P2PDMA
+int pci_p2pdma_add_resource(struct pci_dev *pdev, int bar, size_t size,
+		u64 offset);
+int pci_p2pdma_distance_many(struct pci_dev *provider, struct device **clients,
+			     int num_clients, bool verbose);
+bool pci_has_p2pmem(struct pci_dev *pdev);
+struct pci_dev *pci_p2pmem_find_many(struct device **clients, int num_clients);
+void *pci_alloc_p2pmem(struct pci_dev *pdev, size_t size);
+void pci_free_p2pmem(struct pci_dev *pdev, void *addr, size_t size);
+pci_bus_addr_t pci_p2pmem_virt_to_bus(struct pci_dev *pdev, void *addr);
+struct scatterlist *pci_p2pmem_alloc_sgl(struct pci_dev *pdev,
+					 unsigned int *nents, u32 length);
+void pci_p2pmem_free_sgl(struct pci_dev *pdev, struct scatterlist *sgl);
+void pci_p2pmem_publish(struct pci_dev *pdev, bool publish);
+#else /* CONFIG_PCI_P2PDMA */
+static inline int pci_p2pdma_add_resource(struct pci_dev *pdev, int bar,
+		size_t size, u64 offset)
+{
+	return -EOPNOTSUPP;
+}
+static inline int pci_p2pdma_distance_many(struct pci_dev *provider,
+	struct device **clients, int num_clients, bool verbose)
+{
+	return -1;
+}
+static inline bool pci_has_p2pmem(struct pci_dev *pdev)
+{
+	return false;
+}
+static inline struct pci_dev *pci_p2pmem_find_many(struct device **clients,
+						   int num_clients)
+{
+	return NULL;
+}
+static inline void *pci_alloc_p2pmem(struct pci_dev *pdev, size_t size)
+{
+	return NULL;
+}
+static inline void pci_free_p2pmem(struct pci_dev *pdev, void *addr,
+		size_t size)
+{
+}
+static inline pci_bus_addr_t pci_p2pmem_virt_to_bus(struct pci_dev *pdev,
+						    void *addr)
+{
+	return 0;
+}
+static inline struct scatterlist *pci_p2pmem_alloc_sgl(struct pci_dev *pdev,
+		unsigned int *nents, u32 length)
+{
+	return NULL;
+}
+static inline void pci_p2pmem_free_sgl(struct pci_dev *pdev,
+		struct scatterlist *sgl)
+{
+}
+static inline void pci_p2pmem_publish(struct pci_dev *pdev, bool publish)
+{
+}
+#endif /* CONFIG_PCI_P2PDMA */
+
+
+static inline int pci_p2pdma_distance(struct pci_dev *provider,
+	struct device *client, bool verbose)
+{
+	return pci_p2pdma_distance_many(provider, &client, 1, verbose);
+}
+
+static inline struct pci_dev *pci_p2pmem_find(struct device *client)
+{
+	return pci_p2pmem_find_many(&client, 1);
+}
+
+#endif /* _LINUX_PCI_P2P_H */
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 6925828f9f25..bf5277768f69 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -281,6 +281,7 @@ struct pcie_link_state;
 struct pci_vpd;
 struct pci_sriov;
 struct pci_ats;
+struct pci_p2pdma;
 
 /* The pci_dev structure describes PCI devices */
 struct pci_dev {
@@ -439,6 +440,9 @@ struct pci_dev {
 #ifdef CONFIG_PCI_PASID
 	u16		pasid_features;
 #endif
+#ifdef CONFIG_PCI_P2PDMA
+	struct pci_p2pdma *p2pdma;
+#endif
 	phys_addr_t	rom;		/* Physical address if not from BAR */
 	size_t		romlen;		/* Length if not from BAR */
 	char		*driver_override; /* Driver name to force a match */