xen: fixes for 5.3-rc3

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Merge tag 'for-linus-5.3a-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull xen fixes from Juergen Gross:

 - a small cleanup

 - a fix for a build error on ARM with some configs

 - a fix of a patch for the Xen gntdev driver

 - three patches for fixing a potential problem in the swiotlb-xen
   driver which Konrad was fine with me carrying them through the Xen
   tree

* tag 'for-linus-5.3a-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/swiotlb: remember having called xen_create_contiguous_region()
  xen/swiotlb: simplify range_straddles_page_boundary()
  xen/swiotlb: fix condition for calling xen_destroy_contiguous_region()
  xen: avoid link error on ARM
  xen/gntdev.c: Replace vm_map_pages() with vm_map_pages_zero()
  xen/pciback: remove set but not used variable 'old_state'

drivers/xen/gntdev.c

@@ -1143,7 +1143,7 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma)
 		goto out_put_map;
 
 	if (!use_ptemod) {
-		err = vm_map_pages(vma, map->pages, map->count);
+		err = vm_map_pages_zero(vma, map->pages, map->count);
 		if (err)
 			goto out_put_map;
 	} else {

drivers/xen/privcmd.c

@@ -724,25 +724,6 @@ static long privcmd_ioctl_restrict(struct file *file, void __user *udata)
 	return 0;
 }
 
-struct remap_pfn {
-	struct mm_struct *mm;
-	struct page **pages;
-	pgprot_t prot;
-	unsigned long i;
-};
-
-static int remap_pfn_fn(pte_t *ptep, unsigned long addr, void *data)
-{
-	struct remap_pfn *r = data;
-	struct page *page = r->pages[r->i];
-	pte_t pte = pte_mkspecial(pfn_pte(page_to_pfn(page), r->prot));
-
-	set_pte_at(r->mm, addr, ptep, pte);
-	r->i++;
-
-	return 0;
-}
-
 static long privcmd_ioctl_mmap_resource(struct file *file, void __user *udata)
 {
 	struct privcmd_data *data = file->private_data;
@@ -774,7 +755,8 @@ static long privcmd_ioctl_mmap_resource(struct file *file, void __user *udata)
 		goto out;
 	}
 
-	if (xen_feature(XENFEAT_auto_translated_physmap)) {
+	if (IS_ENABLED(CONFIG_XEN_AUTO_XLATE) &&
+	    xen_feature(XENFEAT_auto_translated_physmap)) {
 		unsigned int nr = DIV_ROUND_UP(kdata.num, XEN_PFN_PER_PAGE);
 		struct page **pages;
 		unsigned int i;
@@ -808,16 +790,9 @@ static long privcmd_ioctl_mmap_resource(struct file *file, void __user *udata)
 	if (rc)
 		goto out;
 
-	if (xen_feature(XENFEAT_auto_translated_physmap)) {
-		struct remap_pfn r = {
-			.mm = vma->vm_mm,
-			.pages = vma->vm_private_data,
-			.prot = vma->vm_page_prot,
-		};
-
-		rc = apply_to_page_range(r.mm, kdata.addr,
-					 kdata.num << PAGE_SHIFT,
-					 remap_pfn_fn, &r);
+	if (IS_ENABLED(CONFIG_XEN_AUTO_XLATE) &&
+	    xen_feature(XENFEAT_auto_translated_physmap)) {
+		rc = xen_remap_vma_range(vma, kdata.addr, kdata.num << PAGE_SHIFT);
 	} else {
 		unsigned int domid =
 			(xdata.flags & XENMEM_rsrc_acq_caller_owned) ?

drivers/xen/swiotlb-xen.c

@@ -83,34 +83,18 @@ static inline dma_addr_t xen_virt_to_bus(void *address)
 	return xen_phys_to_bus(virt_to_phys(address));
 }
 
-static int check_pages_physically_contiguous(unsigned long xen_pfn,
-					     unsigned int offset,
-					     size_t length)
-{
-	unsigned long next_bfn;
-	int i;
-	int nr_pages;
-
-	next_bfn = pfn_to_bfn(xen_pfn);
-	nr_pages = (offset + length + XEN_PAGE_SIZE-1) >> XEN_PAGE_SHIFT;
-
-	for (i = 1; i < nr_pages; i++) {
-		if (pfn_to_bfn(++xen_pfn) != ++next_bfn)
-			return 0;
-	}
-	return 1;
-}
-
 static inline int range_straddles_page_boundary(phys_addr_t p, size_t size)
 {
-	unsigned long xen_pfn = XEN_PFN_DOWN(p);
-	unsigned int offset = p & ~XEN_PAGE_MASK;
+	unsigned long next_bfn, xen_pfn = XEN_PFN_DOWN(p);
+	unsigned int i, nr_pages = XEN_PFN_UP(xen_offset_in_page(p) + size);
 
-	if (offset + size <= XEN_PAGE_SIZE)
-		return 0;
-	if (check_pages_physically_contiguous(xen_pfn, offset, size))
-		return 0;
-	return 1;
+	next_bfn = pfn_to_bfn(xen_pfn);
+
+	for (i = 1; i < nr_pages; i++)
+		if (pfn_to_bfn(++xen_pfn) != ++next_bfn)
+			return 1;
+
+	return 0;
 }
 
 static int is_xen_swiotlb_buffer(dma_addr_t dma_addr)
@@ -338,6 +322,7 @@ xen_swiotlb_alloc_coherent(struct device *hwdev, size_t size,
 			xen_free_coherent_pages(hwdev, size, ret, (dma_addr_t)phys, attrs);
 			return NULL;
 		}
+		SetPageXenRemapped(virt_to_page(ret));
 	}
 	memset(ret, 0, size);
 	return ret;
@@ -361,8 +346,9 @@ xen_swiotlb_free_coherent(struct device *hwdev, size_t size, void *vaddr,
 	/* Convert the size to actually allocated. */
 	size = 1UL << (order + XEN_PAGE_SHIFT);
 
-	if (((dev_addr + size - 1 <= dma_mask)) ||
-	    range_straddles_page_boundary(phys, size))
+	if (!WARN_ON((dev_addr + size - 1 > dma_mask) ||
+		     range_straddles_page_boundary(phys, size)) &&
+	    TestClearPageXenRemapped(virt_to_page(vaddr)))
 		xen_destroy_contiguous_region(phys, order);
 
 	xen_free_coherent_pages(hwdev, size, vaddr, (dma_addr_t)phys, attrs);

drivers/xen/xen-pciback/conf_space_capability.c

@@ -116,13 +116,12 @@ static int pm_ctrl_write(struct pci_dev *dev, int offset, u16 new_value,
 {
 	int err;
 	u16 old_value;
-	pci_power_t new_state, old_state;
+	pci_power_t new_state;
 
 	err = pci_read_config_word(dev, offset, &old_value);
 	if (err)
 		goto out;
 
-	old_state = (pci_power_t)(old_value & PCI_PM_CTRL_STATE_MASK);
 	new_state = (pci_power_t)(new_value & PCI_PM_CTRL_STATE_MASK);
 
 	new_value &= PM_OK_BITS;

drivers/xen/xlate_mmu.c

@@ -262,3 +262,35 @@ int __init xen_xlate_map_ballooned_pages(xen_pfn_t **gfns, void **virt,
 	return 0;
 }
 EXPORT_SYMBOL_GPL(xen_xlate_map_ballooned_pages);
+
+struct remap_pfn {
+	struct mm_struct *mm;
+	struct page **pages;
+	pgprot_t prot;
+	unsigned long i;
+};
+
+static int remap_pfn_fn(pte_t *ptep, unsigned long addr, void *data)
+{
+	struct remap_pfn *r = data;
+	struct page *page = r->pages[r->i];
+	pte_t pte = pte_mkspecial(pfn_pte(page_to_pfn(page), r->prot));
+
+	set_pte_at(r->mm, addr, ptep, pte);
+	r->i++;
+
+	return 0;
+}
+
+/* Used by the privcmd module, but has to be built-in on ARM */
+int xen_remap_vma_range(struct vm_area_struct *vma, unsigned long addr, unsigned long len)
+{
+	struct remap_pfn r = {
+		.mm = vma->vm_mm,
+		.pages = vma->vm_private_data,
+		.prot = vma->vm_page_prot,
+	};
+
+	return apply_to_page_range(vma->vm_mm, addr, len, remap_pfn_fn, &r);
+}
+EXPORT_SYMBOL_GPL(xen_remap_vma_range);

include/linux/page-flags.h

@@ -152,6 +152,8 @@ enum pageflags {
 	PG_savepinned = PG_dirty,
 	/* Has a grant mapping of another (foreign) domain's page. */
 	PG_foreign = PG_owner_priv_1,
+	/* Remapped by swiotlb-xen. */
+	PG_xen_remapped = PG_owner_priv_1,
 
 	/* SLOB */
 	PG_slob_free = PG_private,
@@ -329,6 +331,8 @@ PAGEFLAG(Pinned, pinned, PF_NO_COMPOUND)
 	TESTSCFLAG(Pinned, pinned, PF_NO_COMPOUND)
 PAGEFLAG(SavePinned, savepinned, PF_NO_COMPOUND);
 PAGEFLAG(Foreign, foreign, PF_NO_COMPOUND);
+PAGEFLAG(XenRemapped, xen_remapped, PF_NO_COMPOUND)
+	TESTCLEARFLAG(XenRemapped, xen_remapped, PF_NO_COMPOUND)
 
 PAGEFLAG(Reserved, reserved, PF_NO_COMPOUND)
 	__CLEARPAGEFLAG(Reserved, reserved, PF_NO_COMPOUND)

include/xen/xen-ops.h

@@ -109,6 +109,9 @@ static inline int xen_xlate_unmap_gfn_range(struct vm_area_struct *vma,
 }
 #endif
 
+int xen_remap_vma_range(struct vm_area_struct *vma, unsigned long addr,
+			unsigned long len);
+
 /*
  * xen_remap_domain_gfn_array() - map an array of foreign frames by gfn
  * @vma:     VMA to map the pages into