[PATCH v2 rebased 5/9] powerpc/mm: Call radix__arch_get_unmapped_area() from arch_get_unmapped_area()

[Christophe Leroy]

Instead of setting mm->get_unmapped_area() to either
arch_get_unmapped_area() or radix__arch_get_unmapped_area(),
always set it to arch_get_unmapped_area() and call
radix__arch_get_unmapped_area() from there when radix is enabled.

To keep radix__arch_get_unmapped_area() static, move it to slice.c

Do the same with radix__arch_get_unmapped_area_topdown()

Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
---
 arch/powerpc/mm/book3s64/slice.c | 104 ++++++++++++++++++++++++++
 arch/powerpc/mm/mmap.c           | 123 -------------------------------
 2 files changed, 104 insertions(+), 123 deletions(-)

diff --git a/arch/powerpc/mm/book3s64/slice.c b/arch/powerpc/mm/book3s64/slice.c
index 4c3e9601fdf6..99742dde811c 100644
--- a/arch/powerpc/mm/book3s64/slice.c
+++ b/arch/powerpc/mm/book3s64/slice.c
@@ -639,12 +639,113 @@ unsigned long slice_get_unmapped_area(unsigned long addr, unsigned long len,
 }
 EXPORT_SYMBOL_GPL(slice_get_unmapped_area);
 
+/*
+ * Same function as generic code used only for radix, because we don't need to overload
+ * the generic one. But we will have to duplicate, because hash select
+ * HAVE_ARCH_UNMAPPED_AREA
+ */
+static unsigned long
+radix__arch_get_unmapped_area(struct file *filp, unsigned long addr, unsigned long len,
+			      unsigned long pgoff, unsigned long flags)
+{
+	struct mm_struct *mm = current->mm;
+	struct vm_area_struct *vma;
+	int fixed = (flags & MAP_FIXED);
+	unsigned long high_limit;
+	struct vm_unmapped_area_info info;
+
+	high_limit = DEFAULT_MAP_WINDOW;
+	if (addr >= high_limit || (fixed && (addr + len > high_limit)))
+		high_limit = TASK_SIZE;
+
+	if (len > high_limit)
+		return -ENOMEM;
+
+	if (fixed) {
+		if (addr > high_limit - len)
+			return -ENOMEM;
+		return addr;
+	}
+
+	if (addr) {
+		addr = PAGE_ALIGN(addr);
+		vma = find_vma(mm, addr);
+		if (high_limit - len >= addr && addr >= mmap_min_addr &&
+		    (!vma || addr + len <= vm_start_gap(vma)))
+			return addr;
+	}
+
+	info.flags = 0;
+	info.length = len;
+	info.low_limit = mm->mmap_base;
+	info.high_limit = high_limit;
+	info.align_mask = 0;
+
+	return vm_unmapped_area(&info);
+}
+
+static unsigned long
+radix__arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
+				      const unsigned long len, const unsigned long pgoff,
+				      const unsigned long flags)
+{
+	struct vm_area_struct *vma;
+	struct mm_struct *mm = current->mm;
+	unsigned long addr = addr0;
+	int fixed = (flags & MAP_FIXED);
+	unsigned long high_limit;
+	struct vm_unmapped_area_info info;
+
+	high_limit = DEFAULT_MAP_WINDOW;
+	if (addr >= high_limit || (fixed && (addr + len > high_limit)))
+		high_limit = TASK_SIZE;
+
+	if (len > high_limit)
+		return -ENOMEM;
+
+	if (fixed) {
+		if (addr > high_limit - len)
+			return -ENOMEM;
+		return addr;
+	}
+
+	if (addr) {
+		addr = PAGE_ALIGN(addr);
+		vma = find_vma(mm, addr);
+		if (high_limit - len >= addr && addr >= mmap_min_addr &&
+		    (!vma || addr + len <= vm_start_gap(vma)))
+			return addr;
+	}
+
+	info.flags = VM_UNMAPPED_AREA_TOPDOWN;
+	info.length = len;
+	info.low_limit = max(PAGE_SIZE, mmap_min_addr);
+	info.high_limit = mm->mmap_base + (high_limit - DEFAULT_MAP_WINDOW);
+	info.align_mask = 0;
+
+	addr = vm_unmapped_area(&info);
+	if (!(addr & ~PAGE_MASK))
+		return addr;
+	VM_BUG_ON(addr != -ENOMEM);
+
+	/*
+	 * A failed mmap() very likely causes application failure,
+	 * so fall back to the bottom-up function here. This scenario
+	 * can happen with large stack limits and large mmap()
+	 * allocations.
+	 */
+	return radix__arch_get_unmapped_area(filp, addr0, len, pgoff, flags);
+}
+
 unsigned long arch_get_unmapped_area(struct file *filp,
 				     unsigned long addr,
 				     unsigned long len,
 				     unsigned long pgoff,
 				     unsigned long flags)
 {
+	if (radix_enabled())
+		return radix__arch_get_unmapped_area(filp, addr, len, pgoff, flags);
+
 	return slice_get_unmapped_area(addr, len, flags,
 				       mm_ctx_user_psize(&current->mm->context), 0);
 }
@@ -655,6 +756,9 @@ unsigned long arch_get_unmapped_area_topdown(struct file *filp,
 					     const unsigned long pgoff,
 					     const unsigned long flags)
 {
+	if (radix_enabled())
+		return radix__arch_get_unmapped_area_topdown(filp, addr0, len, pgoff, flags);
+
 	return slice_get_unmapped_area(addr0, len, flags,
 				       mm_ctx_user_psize(&current->mm->context), 1);
 }
diff --git a/arch/powerpc/mm/mmap.c b/arch/powerpc/mm/mmap.c
index ae683fdc716c..5972d619d274 100644
--- a/arch/powerpc/mm/mmap.c
+++ b/arch/powerpc/mm/mmap.c
@@ -80,126 +80,6 @@ static inline unsigned long mmap_base(unsigned long rnd,
 	return PAGE_ALIGN(DEFAULT_MAP_WINDOW - gap - rnd);
 }
 
-#ifdef CONFIG_PPC_RADIX_MMU
-/*
- * Same function as generic code used only for radix, because we don't need to overload
- * the generic one. But we will have to duplicate, because hash select
- * HAVE_ARCH_UNMAPPED_AREA
- */
-static unsigned long
-radix__arch_get_unmapped_area(struct file *filp, unsigned long addr,
-			     unsigned long len, unsigned long pgoff,
-			     unsigned long flags)
-{
-	struct mm_struct *mm = current->mm;
-	struct vm_area_struct *vma;
-	int fixed = (flags & MAP_FIXED);
-	unsigned long high_limit;
-	struct vm_unmapped_area_info info;
-
-	high_limit = DEFAULT_MAP_WINDOW;
-	if (addr >= high_limit || (fixed && (addr + len > high_limit)))
-		high_limit = TASK_SIZE;
-
-	if (len > high_limit)
-		return -ENOMEM;
-
-	if (fixed) {
-		if (addr > high_limit - len)
-			return -ENOMEM;
-		return addr;
-	}
-
-	if (addr) {
-		addr = PAGE_ALIGN(addr);
-		vma = find_vma(mm, addr);
-		if (high_limit - len >= addr && addr >= mmap_min_addr &&
-		    (!vma || addr + len <= vm_start_gap(vma)))
-			return addr;
-	}
-
-	info.flags = 0;
-	info.length = len;
-	info.low_limit = mm->mmap_base;
-	info.high_limit = high_limit;
-	info.align_mask = 0;
-
-	return vm_unmapped_area(&info);
-}
-
-static unsigned long
-radix__arch_get_unmapped_area_topdown(struct file *filp,
-				     const unsigned long addr0,
-				     const unsigned long len,
-				     const unsigned long pgoff,
-				     const unsigned long flags)
-{
-	struct vm_area_struct *vma;
-	struct mm_struct *mm = current->mm;
-	unsigned long addr = addr0;
-	int fixed = (flags & MAP_FIXED);
-	unsigned long high_limit;
-	struct vm_unmapped_area_info info;
-
-	high_limit = DEFAULT_MAP_WINDOW;
-	if (addr >= high_limit || (fixed && (addr + len > high_limit)))
-		high_limit = TASK_SIZE;
-
-	if (len > high_limit)
-		return -ENOMEM;
-
-	if (fixed) {
-		if (addr > high_limit - len)
-			return -ENOMEM;
-		return addr;
-	}
-
-	if (addr) {
-		addr = PAGE_ALIGN(addr);
-		vma = find_vma(mm, addr);
-		if (high_limit - len >= addr && addr >= mmap_min_addr &&
-		    (!vma || addr + len <= vm_start_gap(vma)))
-			return addr;
-	}
-
-	info.flags = VM_UNMAPPED_AREA_TOPDOWN;
-	info.length = len;
-	info.low_limit = max(PAGE_SIZE, mmap_min_addr);
-	info.high_limit = mm->mmap_base + (high_limit - DEFAULT_MAP_WINDOW);
-	info.align_mask = 0;
-
-	addr = vm_unmapped_area(&info);
-	if (!(addr & ~PAGE_MASK))
-		return addr;
-	VM_BUG_ON(addr != -ENOMEM);
-
-	/*
-	 * A failed mmap() very likely causes application failure,
-	 * so fall back to the bottom-up function here. This scenario
-	 * can happen with large stack limits and large mmap()
-	 * allocations.
-	 */
-	return radix__arch_get_unmapped_area(filp, addr0, len, pgoff, flags);
-}
-
-static void radix__arch_pick_mmap_layout(struct mm_struct *mm,
-					unsigned long random_factor,
-					struct rlimit *rlim_stack)
-{
-	if (mmap_is_legacy(rlim_stack)) {
-		mm->mmap_base = TASK_UNMAPPED_BASE;
-		mm->get_unmapped_area = radix__arch_get_unmapped_area;
-	} else {
-		mm->mmap_base = mmap_base(random_factor, rlim_stack);
-		mm->get_unmapped_area = radix__arch_get_unmapped_area_topdown;
-	}
-}
-#else
-/* dummy */
-extern void radix__arch_pick_mmap_layout(struct mm_struct *mm,
-					unsigned long random_factor,
-					struct rlimit *rlim_stack);
-#endif
 /*
  * This function, called very early during the creation of a new
  * process VM image, sets up which VM layout function to use:
@@ -211,9 +91,6 @@ void arch_pick_mmap_layout(struct mm_struct *mm, struct rlimit *rlim_stack)
 	if (current->flags & PF_RANDOMIZE)
 		random_factor = arch_mmap_rnd();
 
-	if (radix_enabled())
-		return radix__arch_pick_mmap_layout(mm, random_factor,
-						    rlim_stack);
 	/*
 	 * Fall back to the standard layout if the personality
 	 * bit is set, or if the expected stack growth is unlimited:
-- 
2.33.1