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: Stephen Rothwell <sfr@canb.auug.org.au>

diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
index 13c9b19ec923f39bff2ea49f5c7e8b5eef38124a..bf0a1b7a824e32dd21ac369aecaa211a40e09325 100644 (file)
--- 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 e23b67f37a6f7272a2a4369e44c3e12400a37b2b..46d48d2a444fa97a67318d8b9cd6c84cb9905a84 100644 (file)
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -2923,8 +2923,7 @@ 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;
 
                /*
@@ -2937,11 +2936,13 @@ 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: