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>

diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
index 54ec0736a656faad2035b9b704fcbd57c7fae522..1dabd6f224864e760e14b34129342516d6d24acc 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 fe0af8db71e0d39f333227dd5975bc0a8359eab8..71dd29fe618b6b8705f1e3c2a7c878089fbfa997 100644 (file)
--- 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: