1 files changed, 21 insertions, 40 deletions

diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c
index 4f47a13cb500..8d955c25aed3 100644
--- a/drivers/pci/p2pdma.c
+++ b/drivers/pci/p2pdma.c
@@ -90,7 +90,7 @@ static ssize_t published_show(struct device *dev, struct device_attribute *attr,
 static DEVICE_ATTR_RO(published);
 
 static int p2pmem_alloc_mmap(struct file *filp, struct kobject *kobj,
-		struct bin_attribute *attr, struct vm_area_struct *vma)
+		const struct bin_attribute *attr, struct vm_area_struct *vma)
 {
 	struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));
 	size_t len = vma->vm_end - vma->vm_start;
@@ -140,13 +140,22 @@ static int p2pmem_alloc_mmap(struct file *filp, struct kobject *kobj,
 	rcu_read_unlock();
 
 	for (vaddr = vma->vm_start; vaddr < vma->vm_end; vaddr += PAGE_SIZE) {
-		ret = vm_insert_page(vma, vaddr, virt_to_page(kaddr));
+		struct page *page = virt_to_page(kaddr);
+
+		/*
+		 * Initialise the refcount for the freshly allocated page. As
+		 * we have just allocated the page no one else should be
+		 * using it.
+		 */
+		VM_WARN_ON_ONCE_PAGE(!page_ref_count(page), page);
+		set_page_count(page, 1);
+		ret = vm_insert_page(vma, vaddr, page);
 		if (ret) {
 			gen_pool_free(p2pdma->pool, (uintptr_t)kaddr, len);
 			return ret;
 		}
 		percpu_ref_get(ref);
-		put_page(virt_to_page(kaddr));
+		put_page(page);
 		kaddr += PAGE_SIZE;
 		len -= PAGE_SIZE;
 	}
@@ -161,7 +170,7 @@ out:
 	return ret;
 }
 
-static struct bin_attribute p2pmem_alloc_attr = {
+static const struct bin_attribute p2pmem_alloc_attr = {
 	.attr = { .name = "allocate", .mode = 0660 },
 	.mmap = p2pmem_alloc_mmap,
 	/*
@@ -180,20 +189,20 @@ static struct attribute *p2pmem_attrs[] = {
 	NULL,
 };
 
-static struct bin_attribute *p2pmem_bin_attrs[] = {
+static const struct bin_attribute *const p2pmem_bin_attrs[] = {
 	&p2pmem_alloc_attr,
 	NULL,
 };
 
 static const struct attribute_group p2pmem_group = {
 	.attrs = p2pmem_attrs,
-	.bin_attrs = p2pmem_bin_attrs,
+	.bin_attrs_new = p2pmem_bin_attrs,
 	.name = "p2pmem",
 };
 
 static void p2pdma_page_free(struct page *page)
 {
-	struct pci_p2pdma_pagemap *pgmap = to_p2p_pgmap(page->pgmap);
+	struct pci_p2pdma_pagemap *pgmap = to_p2p_pgmap(page_pgmap(page));
 	/* safe to dereference while a reference is held to the percpu ref */
 	struct pci_p2pdma *p2pdma =
 		rcu_dereference_protected(pgmap->provider->p2pdma, 1);
@@ -995,40 +1004,12 @@ static enum pci_p2pdma_map_type pci_p2pdma_map_type(struct dev_pagemap *pgmap,
 	return type;
 }
 
-/**
- * pci_p2pdma_map_segment - map an sg segment determining the mapping type
- * @state: State structure that should be declared outside of the for_each_sg()
- *	loop and initialized to zero.
- * @dev: DMA device that's doing the mapping operation
- * @sg: scatterlist segment to map
- *
- * This is a helper to be used by non-IOMMU dma_map_sg() implementations where
- * the sg segment is the same for the page_link and the dma_address.
- *
- * Attempt to map a single segment in an SGL with the PCI bus address.
- * The segment must point to a PCI P2PDMA page and thus must be
- * wrapped in a is_pci_p2pdma_page(sg_page(sg)) check.
- *
- * Returns the type of mapping used and maps the page if the type is
- * PCI_P2PDMA_MAP_BUS_ADDR.
- */
-enum pci_p2pdma_map_type
-pci_p2pdma_map_segment(struct pci_p2pdma_map_state *state, struct device *dev,
-		       struct scatterlist *sg)
+void __pci_p2pdma_update_state(struct pci_p2pdma_map_state *state,
+		struct device *dev, struct page *page)
 {
-	if (state->pgmap != sg_page(sg)->pgmap) {
-		state->pgmap = sg_page(sg)->pgmap;
-		state->map = pci_p2pdma_map_type(state->pgmap, dev);
-		state->bus_off = to_p2p_pgmap(state->pgmap)->bus_offset;
-	}
-
-	if (state->map == PCI_P2PDMA_MAP_BUS_ADDR) {
-		sg->dma_address = sg_phys(sg) + state->bus_off;
-		sg_dma_len(sg) = sg->length;
-		sg_dma_mark_bus_address(sg);
-	}
-
-	return state->map;
+	state->pgmap = page_pgmap(page);
+	state->map = pci_p2pdma_map_type(state->pgmap, dev);
+	state->bus_off = to_p2p_pgmap(state->pgmap)->bus_offset;
 }
 
 /**