From 3382bbee0464bf31e63853c6ec2a83ead77a01cc Mon Sep 17 00:00:00 2001
From: Christophe Leroy <christophe.leroy@csgroup.eu>
Date: Wed, 30 Jun 2021 18:48:09 -0700
Subject: [PATCH] mm/vmalloc: enable mapping of huge pages at pte level in
 vmalloc

On some architectures like powerpc, there are huge pages that are mapped
at pte level.

Enable it in vmalloc.

For that, architectures can provide arch_vmap_pte_supported_shift() that
returns the shift for pages to map at pte level.

Link: https://lkml.kernel.org/r/2c717e3b1fba1894d890feb7669f83025bfa314d.1620795204.git.christophe.leroy@csgroup.eu
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Uladzislau Rezki <uladzislau.rezki@sony.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 include/linux/vmalloc.h |  7 +++++++
 mm/vmalloc.c            | 13 +++++++------
 2 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
index 54ec0736a656..1dabd6f22486 100644
--- a/include/linux/vmalloc.h
+++ b/include/linux/vmalloc.h
@@ -112,6 +112,13 @@ static inline unsigned long arch_vmap_pte_range_map_size(unsigned long addr, uns
 }
 #endif
 
+#ifndef arch_vmap_pte_supported_shift
+static inline int arch_vmap_pte_supported_shift(unsigned long size)
+{
+	return PAGE_SHIFT;
+}
+#endif
+
 /*
  *	Highlevel APIs for driver use
  */
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index fe0af8db71e0..71dd29fe618b 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -2927,8 +2927,7 @@ void *__vmalloc_node_range(unsigned long size, unsigned long align,
 		return NULL;
 	}
 
-	if (vmap_allow_huge && !(vm_flags & VM_NO_HUGE_VMAP) &&
-			arch_vmap_pmd_supported(prot)) {
+	if (vmap_allow_huge && !(vm_flags & VM_NO_HUGE_VMAP)) {
 		unsigned long size_per_node;
 
 		/*
@@ -2941,11 +2940,13 @@ void *__vmalloc_node_range(unsigned long size, unsigned long align,
 		size_per_node = size;
 		if (node == NUMA_NO_NODE)
 			size_per_node /= num_online_nodes();
-		if (size_per_node >= PMD_SIZE) {
+		if (arch_vmap_pmd_supported(prot) && size_per_node >= PMD_SIZE)
 			shift = PMD_SHIFT;
-			align = max(real_align, 1UL << shift);
-			size = ALIGN(real_size, 1UL << shift);
-		}
+		else
+			shift = arch_vmap_pte_supported_shift(size_per_node);
+
+		align = max(real_align, 1UL << shift);
+		size = ALIGN(real_size, 1UL << shift);
 	}
 
 again: