[PATCH v1 15/16] mm: rename zap_vma_ptes() to zap_special_vma_range()

["David Hildenbrand (Arm)" <david@kernel.org>]

zap_vma_ptes() is the only zapping function we export to modules.

It's essentially a wrapper around zap_vma_range(), however, with some
safety checks:
* That the passed range fits fully into the VMA
* That it's only used for VM_PFNMAP

We might want to support VM_MIXEDMAP soon as well, so use the
more-generic term "special vma", although "special" is a bit overloaded.
Maybe we'll later just support any VM_SPECIAL flag.

While at it, improve the kerneldoc.

Signed-off-by: David Hildenbrand (Arm) <david@kernel.org>
---
 arch/x86/kernel/cpu/sgx/encl.c        |  2 +-
 drivers/comedi/comedi_fops.c          |  2 +-
 drivers/gpu/drm/i915/i915_mm.c        |  4 ++--
 drivers/infiniband/core/uverbs_main.c |  6 +++---
 drivers/misc/sgi-gru/grumain.c        |  2 +-
 include/linux/mm.h                    |  2 +-
 mm/memory.c                           | 16 +++++++---------
 7 files changed, 16 insertions(+), 18 deletions(-)

diff --git a/arch/x86/kernel/cpu/sgx/encl.c b/arch/x86/kernel/cpu/sgx/encl.c
index ac60ebde5d9b..3f0222d10f6e 100644
--- a/arch/x86/kernel/cpu/sgx/encl.c
+++ b/arch/x86/kernel/cpu/sgx/encl.c
@@ -1220,7 +1220,7 @@ void sgx_zap_enclave_ptes(struct sgx_encl *encl, unsigned long addr)
 
 			ret = sgx_encl_find(encl_mm->mm, addr, &vma);
 			if (!ret && encl == vma->vm_private_data)
-				zap_vma_ptes(vma, addr, PAGE_SIZE);
+				zap_special_vma_range(vma, addr, PAGE_SIZE);
 
 			mmap_read_unlock(encl_mm->mm);
 
diff --git a/drivers/comedi/comedi_fops.c b/drivers/comedi/comedi_fops.c
index 48a8a607a84c..b91e0b5ac394 100644
--- a/drivers/comedi/comedi_fops.c
+++ b/drivers/comedi/comedi_fops.c
@@ -2588,7 +2588,7 @@ static int comedi_mmap(struct file *file, struct vm_area_struct *vma)
 	 * remap_pfn_range() because we call remap_pfn_range() in a loop.
 	 */
 	if (retval)
-		zap_vma_ptes(vma, vma->vm_start, size);
+		zap_special_vma_range(vma, vma->vm_start, size);
 #endif
 
 	if (retval == 0) {
diff --git a/drivers/gpu/drm/i915/i915_mm.c b/drivers/gpu/drm/i915/i915_mm.c
index c33bd3d83069..fd89e7c7d8d6 100644
--- a/drivers/gpu/drm/i915/i915_mm.c
+++ b/drivers/gpu/drm/i915/i915_mm.c
@@ -108,7 +108,7 @@ int remap_io_mapping(struct vm_area_struct *vma,
 
 	err = apply_to_page_range(r.mm, addr, size, remap_pfn, &r);
 	if (unlikely(err)) {
-		zap_vma_ptes(vma, addr, (r.pfn - pfn) << PAGE_SHIFT);
+		zap_special_vma_range(vma, addr, (r.pfn - pfn) << PAGE_SHIFT);
 		return err;
 	}
 
@@ -156,7 +156,7 @@ int remap_io_sg(struct vm_area_struct *vma,
 
 	err = apply_to_page_range(r.mm, addr, size, remap_sg, &r);
 	if (unlikely(err)) {
-		zap_vma_ptes(vma, addr, r.pfn << PAGE_SHIFT);
+		zap_special_vma_range(vma, addr, r.pfn << PAGE_SHIFT);
 		return err;
 	}
 
diff --git a/drivers/infiniband/core/uverbs_main.c b/drivers/infiniband/core/uverbs_main.c
index 7b68967a6301..f5837da47299 100644
--- a/drivers/infiniband/core/uverbs_main.c
+++ b/drivers/infiniband/core/uverbs_main.c
@@ -756,7 +756,7 @@ static void rdma_umap_open(struct vm_area_struct *vma)
 	 * point, so zap it.
 	 */
 	vma->vm_private_data = NULL;
-	zap_vma_ptes(vma, vma->vm_start, vma->vm_end - vma->vm_start);
+	zap_special_vma_range(vma, vma->vm_start, vma->vm_end - vma->vm_start);
 }
 
 static void rdma_umap_close(struct vm_area_struct *vma)
@@ -782,7 +782,7 @@ static void rdma_umap_close(struct vm_area_struct *vma)
 }
 
 /*
- * Once the zap_vma_ptes has been called touches to the VMA will come here and
+ * Once the zap_special_vma_range has been called touches to the VMA will come here and
  * we return a dummy writable zero page for all the pfns.
  */
 static vm_fault_t rdma_umap_fault(struct vm_fault *vmf)
@@ -878,7 +878,7 @@ void uverbs_user_mmap_disassociate(struct ib_uverbs_file *ufile)
 				continue;
 			list_del_init(&priv->list);
 
-			zap_vma_ptes(vma, vma->vm_start,
+			zap_special_vma_range(vma, vma->vm_start,
 				     vma->vm_end - vma->vm_start);
 
 			if (priv->entry) {
diff --git a/drivers/misc/sgi-gru/grumain.c b/drivers/misc/sgi-gru/grumain.c
index 8d749f345246..278b76cbd281 100644
--- a/drivers/misc/sgi-gru/grumain.c
+++ b/drivers/misc/sgi-gru/grumain.c
@@ -542,7 +542,7 @@ void gru_unload_context(struct gru_thread_state *gts, int savestate)
 	int ctxnum = gts->ts_ctxnum;
 
 	if (!is_kernel_context(gts))
-		zap_vma_ptes(gts->ts_vma, UGRUADDR(gts), GRU_GSEG_PAGESIZE);
+		zap_special_vma_range(gts->ts_vma, UGRUADDR(gts), GRU_GSEG_PAGESIZE);
 	cch = get_cch(gru->gs_gru_base_vaddr, ctxnum);
 
 	gru_dbg(grudev, "gts %p, cbrmap 0x%lx, dsrmap 0x%lx\n",
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 833bedd3f739..07f6819db02d 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2833,7 +2833,7 @@ struct page *vm_normal_page_pmd(struct vm_area_struct *vma, unsigned long addr,
 struct page *vm_normal_page_pud(struct vm_area_struct *vma, unsigned long addr,
 		pud_t pud);
 
-void zap_vma_ptes(struct vm_area_struct *vma, unsigned long address,
+void zap_special_vma_range(struct vm_area_struct *vma, unsigned long address,
 		  unsigned long size);
 void zap_vma_range(struct vm_area_struct *vma, unsigned long address,
 			   unsigned long size);
diff --git a/mm/memory.c b/mm/memory.c
index dd737b6d28c0..f3b7b7e16138 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2233,17 +2233,15 @@ void zap_vma_range(struct vm_area_struct *vma, unsigned long address,
 }
 
 /**
- * zap_vma_ptes - remove ptes mapping the vma
- * @vma: vm_area_struct holding ptes to be zapped
- * @address: starting address of pages to zap
+ * zap_special_vma_range - zap all page table entries in a special vma range
+ * @vma: the vma covering the range to zap
+ * @address: starting address of the range to zap
  * @size: number of bytes to zap
  *
- * This function only unmaps ptes assigned to VM_PFNMAP vmas.
- *
- * The entire address range must be fully contained within the vma.
- *
+ * This function does nothing when the provided address range is not fully
+ * contained in @vma, or when the @vma is not VM_PFNMAP.
  */
-void zap_vma_ptes(struct vm_area_struct *vma, unsigned long address,
+void zap_special_vma_range(struct vm_area_struct *vma, unsigned long address,
 		unsigned long size)
 {
 	if (!range_in_vma(vma, address, address + size) ||
@@ -2252,7 +2250,7 @@ void zap_vma_ptes(struct vm_area_struct *vma, unsigned long address,
 
 	zap_vma_range(vma, address, size);
 }
-EXPORT_SYMBOL_GPL(zap_vma_ptes);
+EXPORT_SYMBOL_GPL(zap_special_vma_range);
 
 static pmd_t *walk_to_pmd(struct mm_struct *mm, unsigned long addr)
 {
-- 
2.43.0