[RFC PATCH 4/8] arch/sparc: Teach arch_get_unmapped_area{_topdown} to handle hugetlb mappings

[Oscar Salvador]

We want to stop special casing hugetlb mappings and make them go
through generic channels, so teach arch_get_unmapped_area{_topdown}
to handle those.
sparc specific hugetlb function does not set info.align_offset, and
does not care about adjusting the align_mask for MAP_SHARED cases,
so the same here for compatibility.

Signed-off-by: Oscar Salvador <osalvador@xxxxxxx>
---
 arch/sparc/kernel/sys_sparc_32.c | 16 ++++++++++----
 arch/sparc/kernel/sys_sparc_64.c | 36 +++++++++++++++++++++++++-------
 2 files changed, 40 insertions(+), 12 deletions(-)

diff --git a/arch/sparc/kernel/sys_sparc_32.c b/arch/sparc/kernel/sys_sparc_32.c
index 08a19727795c..fc33ac48ed28 100644
--- a/arch/sparc/kernel/sys_sparc_32.c
+++ b/arch/sparc/kernel/sys_sparc_32.c
@@ -42,12 +42,16 @@ SYSCALL_DEFINE0(getpagesize)
 unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, unsigned long len, unsigned long pgoff, unsigned long flags)
 {
 	struct vm_unmapped_area_info info = {};
+	bool file_hugepage = false;
+
+	if (filp && is_file_hugepages(filp))
+		file_hugepage = true;
 
 	if (flags & MAP_FIXED) {
 		/* We do not accept a shared mapping if it would violate
 		 * cache aliasing constraints.
 		 */
-		if ((flags & MAP_SHARED) &&
+		if (!file_hugepage && (flags & MAP_SHARED) &&
 		    ((addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1)))
 			return -EINVAL;
 		return addr;
@@ -62,9 +66,13 @@ unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, unsi
 	info.length = len;
 	info.low_limit = addr;
 	info.high_limit = TASK_SIZE;
-	info.align_mask = (flags & MAP_SHARED) ?
-		(PAGE_MASK & (SHMLBA - 1)) : 0;
-	info.align_offset = pgoff << PAGE_SHIFT;
+	if (!file_hugepage) {
+		info.align_mask = (flags & MAP_SHARED) ?
+			(PAGE_MASK & (SHMLBA - 1)) : 0;
+		info.align_offset = pgoff << PAGE_SHIFT;
+	} else {
+		info.align_mask = huge_page_mask_align(filp);
+	}
 	return vm_unmapped_area(&info);
 }
 
diff --git a/arch/sparc/kernel/sys_sparc_64.c b/arch/sparc/kernel/sys_sparc_64.c
index d9c3b34ca744..81d8f5467dd8 100644
--- a/arch/sparc/kernel/sys_sparc_64.c
+++ b/arch/sparc/kernel/sys_sparc_64.c
@@ -87,6 +87,16 @@ static inline unsigned long COLOR_ALIGN(unsigned long addr,
 	return base + off;
 }
 
+static unsigned long get_align_mask(struct file *filp, unsigned long flags)
+{
+	if (filp && is_file_hugepages(filp))
+		return huge_page_mask_align(filp);
+	if (filp || (flags & MAP_SHARED))
+		return PAGE_MASK & (SHMLBA - 1);
+
+	return 0;
+}
+
 unsigned long 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;
@@ -94,12 +104,16 @@ unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, unsi
 	unsigned long task_size = TASK_SIZE;
 	int do_color_align;
 	struct vm_unmapped_area_info info = {};
+	bool file_hugepage = false;
+
+	if (filp && is_file_hugepages(filp))
+		file_hugepage = true;
 
 	if (flags & MAP_FIXED) {
 		/* We do not accept a shared mapping if it would violate
 		 * cache aliasing constraints.
 		 */
-		if ((flags & MAP_SHARED) &&
+		if (!file_hugepage && (flags & MAP_SHARED) &&
 		    ((addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1)))
 			return -EINVAL;
 		return addr;
@@ -111,7 +125,7 @@ unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, unsi
 		return -ENOMEM;
 
 	do_color_align = 0;
-	if (filp || (flags & MAP_SHARED))
+	if ((filp || (flags & MAP_SHARED)) && !file_hugepage)
 		do_color_align = 1;
 
 	if (addr) {
@@ -129,8 +143,9 @@ unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, unsi
 	info.length = len;
 	info.low_limit = TASK_UNMAPPED_BASE;
 	info.high_limit = min(task_size, VA_EXCLUDE_START);
-	info.align_mask = do_color_align ? (PAGE_MASK & (SHMLBA - 1)) : 0;
-	info.align_offset = pgoff << PAGE_SHIFT;
+	info.align_mask = get_align_mask(filp, flags);
+	if (!file_hugepage)
+		info.align_offset = pgoff << PAGE_SHIFT;
 	addr = vm_unmapped_area(&info);
 
 	if ((addr & ~PAGE_MASK) && task_size > VA_EXCLUDE_END) {
@@ -154,15 +169,19 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
 	unsigned long addr = addr0;
 	int do_color_align;
 	struct vm_unmapped_area_info info = {};
+	bool file_hugepage = false
 
 	/* This should only ever run for 32-bit processes.  */
 	BUG_ON(!test_thread_flag(TIF_32BIT));
 
+	if (filp && is_file_hugepages(filp))
+		file_hugepage = true;
+
 	if (flags & MAP_FIXED) {
 		/* We do not accept a shared mapping if it would violate
 		 * cache aliasing constraints.
 		 */
-		if ((flags & MAP_SHARED) &&
+		if (!file_hugepage && (flags & MAP_SHARED) &&
 		    ((addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1)))
 			return -EINVAL;
 		return addr;
@@ -172,7 +191,7 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
 		return -ENOMEM;
 
 	do_color_align = 0;
-	if (filp || (flags & MAP_SHARED))
+	if ((filp || (flags & MAP_SHARED)) && !file_hugepage)
 		do_color_align = 1;
 
 	/* requesting a specific address */
@@ -192,8 +211,9 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
 	info.length = len;
 	info.low_limit = PAGE_SIZE;
 	info.high_limit = mm->mmap_base;
-	info.align_mask = do_color_align ? (PAGE_MASK & (SHMLBA - 1)) : 0;
-	info.align_offset = pgoff << PAGE_SHIFT;
+	info.align_mask = get_align_mask(filp, flags);
+	if (!file_hugepage)
+		info.align_offset = pgoff << PAGE_SHIFT;
 	addr = vm_unmapped_area(&info);
 
 	/*
-- 
2.45.2