1 files changed, 116 insertions, 92 deletions

diff --git a/drivers/dax/device.c b/drivers/dax/device.c
index dd8222a42808..22999a402e02 100644
--- a/drivers/dax/device.c
+++ b/drivers/dax/device.c
@@ -4,7 +4,6 @@
 #include <linux/pagemap.h>
 #include <linux/module.h>
 #include <linux/device.h>
-#include <linux/pfn_t.h>
 #include <linux/cdev.h>
 #include <linux/slab.h>
 #include <linux/dax.h>
@@ -14,8 +13,9 @@
 #include "dax-private.h"
 #include "bus.h"
 
-static int check_vma(struct dev_dax *dev_dax, struct vm_area_struct *vma,
-		const char *func)
+static int __check_vma(struct dev_dax *dev_dax, vm_flags_t vm_flags,
+		       unsigned long start, unsigned long end, struct file *file,
+		       const char *func)
 {
 	struct device *dev = &dev_dax->dev;
 	unsigned long mask;
@@ -24,7 +24,7 @@ static int check_vma(struct dev_dax *dev_dax, struct vm_area_struct *vma,
 		return -ENXIO;
 
 	/* prevent private mappings from being established */
-	if ((vma->vm_flags & VM_MAYSHARE) != VM_MAYSHARE) {
+	if ((vm_flags & VM_MAYSHARE) != VM_MAYSHARE) {
 		dev_info_ratelimited(dev,
 				"%s: %s: fail, attempted private mapping\n",
 				current->comm, func);
@@ -32,15 +32,15 @@ static int check_vma(struct dev_dax *dev_dax, struct vm_area_struct *vma,
 	}
 
 	mask = dev_dax->align - 1;
-	if (vma->vm_start & mask || vma->vm_end & mask) {
+	if (start & mask || end & mask) {
 		dev_info_ratelimited(dev,
 				"%s: %s: fail, unaligned vma (%#lx - %#lx, %#lx)\n",
-				current->comm, func, vma->vm_start, vma->vm_end,
+				current->comm, func, start, end,
 				mask);
 		return -EINVAL;
 	}
 
-	if (!vma_is_dax(vma)) {
+	if (!file_is_dax(file)) {
 		dev_info_ratelimited(dev,
 				"%s: %s: fail, vma is not DAX capable\n",
 				current->comm, func);
@@ -50,6 +50,13 @@ static int check_vma(struct dev_dax *dev_dax, struct vm_area_struct *vma,
 	return 0;
 }
 
+static int check_vma(struct dev_dax *dev_dax, struct vm_area_struct *vma,
+		     const char *func)
+{
+	return __check_vma(dev_dax, vma->vm_flags, vma->vm_start, vma->vm_end,
+			   vma->vm_file, func);
+}
+
 /* see "strong" declaration in tools/testing/nvdimm/dax-dev.c */
 __weak phys_addr_t dax_pgoff_to_phys(struct dev_dax *dev_dax, pgoff_t pgoff,
 		unsigned long size)
@@ -73,11 +80,38 @@ __weak phys_addr_t dax_pgoff_to_phys(struct dev_dax *dev_dax, pgoff_t pgoff,
 	return -1;
 }
 
+static void dax_set_mapping(struct vm_fault *vmf, unsigned long pfn,
+			      unsigned long fault_size)
+{
+	unsigned long i, nr_pages = fault_size / PAGE_SIZE;
+	struct file *filp = vmf->vma->vm_file;
+	struct dev_dax *dev_dax = filp->private_data;
+	pgoff_t pgoff;
+
+	/* mapping is only set on the head */
+	if (dev_dax->pgmap->vmemmap_shift)
+		nr_pages = 1;
+
+	pgoff = linear_page_index(vmf->vma,
+			ALIGN_DOWN(vmf->address, fault_size));
+
+	for (i = 0; i < nr_pages; i++) {
+		struct folio *folio = pfn_folio(pfn + i);
+
+		if (folio->mapping)
+			continue;
+
+		folio->mapping = filp->f_mapping;
+		folio->index = pgoff + i;
+	}
+}
+
 static vm_fault_t __dev_dax_pte_fault(struct dev_dax *dev_dax,
-				struct vm_fault *vmf, pfn_t *pfn)
+				struct vm_fault *vmf)
 {
 	struct device *dev = &dev_dax->dev;
 	phys_addr_t phys;
+	unsigned long pfn;
 	unsigned int fault_size = PAGE_SIZE;
 
 	if (check_vma(dev_dax, vmf->vma, __func__))
@@ -98,18 +132,22 @@ static vm_fault_t __dev_dax_pte_fault(struct dev_dax *dev_dax,
 		return VM_FAULT_SIGBUS;
 	}
 
-	*pfn = phys_to_pfn_t(phys, PFN_DEV|PFN_MAP);
+	pfn = PHYS_PFN(phys);
 
-	return vmf_insert_mixed(vmf->vma, vmf->address, *pfn);
+	dax_set_mapping(vmf, pfn, fault_size);
+
+	return vmf_insert_page_mkwrite(vmf, pfn_to_page(pfn),
+					vmf->flags & FAULT_FLAG_WRITE);
 }
 
 static vm_fault_t __dev_dax_pmd_fault(struct dev_dax *dev_dax,
-				struct vm_fault *vmf, pfn_t *pfn)
+				struct vm_fault *vmf)
 {
 	unsigned long pmd_addr = vmf->address & PMD_MASK;
 	struct device *dev = &dev_dax->dev;
 	phys_addr_t phys;
 	pgoff_t pgoff;
+	unsigned long pfn;
 	unsigned int fault_size = PMD_SIZE;
 
 	if (check_vma(dev_dax, vmf->vma, __func__))
@@ -138,19 +176,23 @@ static vm_fault_t __dev_dax_pmd_fault(struct dev_dax *dev_dax,
 		return VM_FAULT_SIGBUS;
 	}
 
-	*pfn = phys_to_pfn_t(phys, PFN_DEV|PFN_MAP);
+	pfn = PHYS_PFN(phys);
+
+	dax_set_mapping(vmf, pfn, fault_size);
 
-	return vmf_insert_pfn_pmd(vmf, *pfn, vmf->flags & FAULT_FLAG_WRITE);
+	return vmf_insert_folio_pmd(vmf, page_folio(pfn_to_page(pfn)),
+				vmf->flags & FAULT_FLAG_WRITE);
 }
 
 #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
 static vm_fault_t __dev_dax_pud_fault(struct dev_dax *dev_dax,
-				struct vm_fault *vmf, pfn_t *pfn)
+				struct vm_fault *vmf)
 {
 	unsigned long pud_addr = vmf->address & PUD_MASK;
 	struct device *dev = &dev_dax->dev;
 	phys_addr_t phys;
 	pgoff_t pgoff;
+	unsigned long pfn;
 	unsigned int fault_size = PUD_SIZE;
 
 
@@ -180,72 +222,42 @@ static vm_fault_t __dev_dax_pud_fault(struct dev_dax *dev_dax,
 		return VM_FAULT_SIGBUS;
 	}
 
-	*pfn = phys_to_pfn_t(phys, PFN_DEV|PFN_MAP);
+	pfn = PHYS_PFN(phys);
+
+	dax_set_mapping(vmf, pfn, fault_size);
 
-	return vmf_insert_pfn_pud(vmf, *pfn, vmf->flags & FAULT_FLAG_WRITE);
+	return vmf_insert_folio_pud(vmf, page_folio(pfn_to_page(pfn)),
+				vmf->flags & FAULT_FLAG_WRITE);
 }
 #else
 static vm_fault_t __dev_dax_pud_fault(struct dev_dax *dev_dax,
-				struct vm_fault *vmf, pfn_t *pfn)
+				struct vm_fault *vmf)
 {
 	return VM_FAULT_FALLBACK;
 }
 #endif /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
 
-static vm_fault_t dev_dax_huge_fault(struct vm_fault *vmf,
-		enum page_entry_size pe_size)
+static vm_fault_t dev_dax_huge_fault(struct vm_fault *vmf, unsigned int order)
 {
 	struct file *filp = vmf->vma->vm_file;
-	unsigned long fault_size;
 	vm_fault_t rc = VM_FAULT_SIGBUS;
 	int id;
-	pfn_t pfn;
 	struct dev_dax *dev_dax = filp->private_data;
 
-	dev_dbg(&dev_dax->dev, "%s: %s (%#lx - %#lx) size = %d\n", current->comm,
-			(vmf->flags & FAULT_FLAG_WRITE) ? "write" : "read",
-			vmf->vma->vm_start, vmf->vma->vm_end, pe_size);
+	dev_dbg(&dev_dax->dev, "%s: op=%s addr=%#lx order=%d\n", current->comm,
+		(vmf->flags & FAULT_FLAG_WRITE) ? "write" : "read",
+		vmf->address & ~((1UL << (order + PAGE_SHIFT)) - 1), order);
 
 	id = dax_read_lock();
-	switch (pe_size) {
-	case PE_SIZE_PTE:
-		fault_size = PAGE_SIZE;
-		rc = __dev_dax_pte_fault(dev_dax, vmf, &pfn);
-		break;
-	case PE_SIZE_PMD:
-		fault_size = PMD_SIZE;
-		rc = __dev_dax_pmd_fault(dev_dax, vmf, &pfn);
-		break;
-	case PE_SIZE_PUD:
-		fault_size = PUD_SIZE;
-		rc = __dev_dax_pud_fault(dev_dax, vmf, &pfn);
-		break;
-	default:
+	if (order == 0)
+		rc = __dev_dax_pte_fault(dev_dax, vmf);
+	else if (order == PMD_ORDER)
+		rc = __dev_dax_pmd_fault(dev_dax, vmf);
+	else if (order == PUD_ORDER)
+		rc = __dev_dax_pud_fault(dev_dax, vmf);
+	else
 		rc = VM_FAULT_SIGBUS;
-	}
 
-	if (rc == VM_FAULT_NOPAGE) {
-		unsigned long i;
-		pgoff_t pgoff;
-
-		/*
-		 * In the device-dax case the only possibility for a
-		 * VM_FAULT_NOPAGE result is when device-dax capacity is
-		 * mapped. No need to consider the zero page, or racing
-		 * conflicting mappings.
-		 */
-		pgoff = linear_page_index(vmf->vma, vmf->address
-				& ~(fault_size - 1));
-		for (i = 0; i < fault_size / PAGE_SIZE; i++) {
-			struct page *page;
-
-			page = pfn_to_page(pfn_t_to_pfn(pfn) + i);
-			if (page->mapping)
-				continue;
-			page->mapping = filp->f_mapping;
-			page->index = pgoff + i;
-		}
-	}
 	dax_read_unlock(id);
 
 	return rc;
@@ -253,7 +265,7 @@ static vm_fault_t dev_dax_huge_fault(struct vm_fault *vmf,
 
 static vm_fault_t dev_dax_fault(struct vm_fault *vmf)
 {
-	return dev_dax_huge_fault(vmf, PE_SIZE_PTE);
+	return dev_dax_huge_fault(vmf, 0);
 }
 
 static int dev_dax_may_split(struct vm_area_struct *vma, unsigned long addr)
@@ -281,8 +293,9 @@ static const struct vm_operations_struct dax_vm_ops = {
 	.pagesize = dev_dax_pagesize,
 };
 
-static int dax_mmap(struct file *filp, struct vm_area_struct *vma)
+static int dax_mmap_prepare(struct vm_area_desc *desc)
 {
+	struct file *filp = desc->file;
 	struct dev_dax *dev_dax = filp->private_data;
 	int rc, id;
 
@@ -293,13 +306,14 @@ static int dax_mmap(struct file *filp, struct vm_area_struct *vma)
 	 * fault time.
 	 */
 	id = dax_read_lock();
-	rc = check_vma(dev_dax, vma, __func__);
+	rc = __check_vma(dev_dax, desc->vm_flags, desc->start, desc->end, filp,
+			 __func__);
 	dax_read_unlock(id);
 	if (rc)
 		return rc;
 
-	vma->vm_ops = &dax_vm_ops;
-	vma->vm_flags |= VM_HUGEPAGE;
+	desc->vm_ops = &dax_vm_ops;
+	desc->vm_flags |= VM_HUGEPAGE;
 	return 0;
 }
 
@@ -326,19 +340,17 @@ static unsigned long dax_get_unmapped_area(struct file *filp,
 	if ((off + len_align) < off)
 		goto out;
 
-	addr_align = current->mm->get_unmapped_area(filp, addr, len_align,
-			pgoff, flags);
+	addr_align = mm_get_unmapped_area(filp, addr, len_align, pgoff, flags);
 	if (!IS_ERR_VALUE(addr_align)) {
 		addr_align += (off - addr_align) & (align - 1);
 		return addr_align;
 	}
  out:
-	return current->mm->get_unmapped_area(filp, addr, len, pgoff, flags);
+	return mm_get_unmapped_area(filp, addr, len, pgoff, flags);
 }
 
 static const struct address_space_operations dev_dax_aops = {
-	.set_page_dirty		= __set_page_dirty_no_writeback,
-	.invalidatepage		= noop_invalidatepage,
+	.dirty_folio	= noop_dirty_folio,
 };
 
 static int dax_open(struct inode *inode, struct file *filp)
@@ -374,8 +386,8 @@ static const struct file_operations dax_fops = {
 	.open = dax_open,
 	.release = dax_release,
 	.get_unmapped_area = dax_get_unmapped_area,
-	.mmap = dax_mmap,
-	.mmap_supported_flags = MAP_SYNC,
+	.mmap_prepare = dax_mmap_prepare,
+	.fop_flags = FOP_MMAP_SYNC,
 };
 
 static void dev_dax_cdev_del(void *cdev)
@@ -388,7 +400,7 @@ static void dev_dax_kill(void *dev_dax)
 	kill_dev_dax(dev_dax);
 }
 
-int dev_dax_probe(struct dev_dax *dev_dax)
+static int dev_dax_probe(struct dev_dax *dev_dax)
 {
 	struct dax_device *dax_dev = dev_dax->dax_dev;
 	struct device *dev = &dev_dax->dev;
@@ -398,17 +410,34 @@ int dev_dax_probe(struct dev_dax *dev_dax)
 	void *addr;
 	int rc, i;
 
-	pgmap = dev_dax->pgmap;
-	if (dev_WARN_ONCE(dev, pgmap && dev_dax->nr_range > 1,
-			"static pgmap / multi-range device conflict\n"))
-		return -EINVAL;
+	if (static_dev_dax(dev_dax))  {
+		if (dev_dax->nr_range > 1) {
+			dev_warn(dev,
+				"static pgmap / multi-range device conflict\n");
+			return -EINVAL;
+		}
 
-	if (!pgmap) {
-		pgmap = devm_kzalloc(dev, sizeof(*pgmap) + sizeof(struct range)
-				* (dev_dax->nr_range - 1), GFP_KERNEL);
+		pgmap = dev_dax->pgmap;
+	} else {
+		if (dev_dax->pgmap) {
+			dev_warn(dev,
+				 "dynamic-dax with pre-populated page map\n");
+			return -EINVAL;
+		}
+
+		pgmap = devm_kzalloc(dev,
+                       struct_size(pgmap, ranges, dev_dax->nr_range - 1),
+                       GFP_KERNEL);
 		if (!pgmap)
 			return -ENOMEM;
+
 		pgmap->nr_range = dev_dax->nr_range;
+		dev_dax->pgmap = pgmap;
+
+		for (i = 0; i < dev_dax->nr_range; i++) {
+			struct range *range = &dev_dax->ranges[i].range;
+			pgmap->ranges[i] = *range;
+		}
 	}
 
 	for (i = 0; i < dev_dax->nr_range; i++) {
@@ -420,12 +449,12 @@ int dev_dax_probe(struct dev_dax *dev_dax)
 					i, range->start, range->end);
 			return -EBUSY;
 		}
-		/* don't update the range for static pgmap */
-		if (!dev_dax->pgmap)
-			pgmap->ranges[i] = *range;
 	}
 
 	pgmap->type = MEMORY_DEVICE_GENERIC;
+	if (dev_dax->align > PAGE_SIZE)
+		pgmap->vmemmap_shift =
+			order_base_2(dev_dax->align >> PAGE_SHIFT);
 	addr = devm_memremap_pages(dev, pgmap);
 	if (IS_ERR(addr))
 		return PTR_ERR(addr);
@@ -433,11 +462,7 @@ int dev_dax_probe(struct dev_dax *dev_dax)
 	inode = dax_inode(dax_dev);
 	cdev = inode->i_cdev;
 	cdev_init(cdev, &dax_fops);
-	if (dev->class) {
-		/* for the CONFIG_DEV_DAX_PMEM_COMPAT case */
-		cdev->owner = dev->parent->driver->owner;
-	} else
-		cdev->owner = dev->driver->owner;
+	cdev->owner = dev->driver->owner;
 	cdev_set_parent(cdev, &dev->kobj);
 	rc = cdev_add(cdev, dev->devt, 1);
 	if (rc)
@@ -450,12 +475,10 @@ int dev_dax_probe(struct dev_dax *dev_dax)
 	run_dax(dax_dev);
 	return devm_add_action_or_reset(dev, dev_dax_kill, dev_dax);
 }
-EXPORT_SYMBOL_GPL(dev_dax_probe);
 
 static struct dax_device_driver device_dax_driver = {
 	.probe = dev_dax_probe,
-	/* all probe actions are unwound by devm, so .remove isn't necessary */
-	.match_always = 1,
+	.type = DAXDRV_DEVICE_TYPE,
 };
 
 static int __init dax_init(void)
@@ -469,6 +492,7 @@ static void __exit dax_exit(void)
 }
 
 MODULE_AUTHOR("Intel Corporation");
+MODULE_DESCRIPTION("Device DAX: direct access device driver");
 MODULE_LICENSE("GPL v2");
 module_init(dax_init);
 module_exit(dax_exit);