mm: provide early_memremap_ro to establish read-only mapping

[mirror_ubuntu-bionic-kernel.git] / mm / early_ioremap.c

diff --git a/mm/early_ioremap.c b/mm/early_ioremap.c
index e10ccd299d6666887ba9347308afaa112ee8816f..0cfadafb3fb00bd9cccb373449857443c443f3a6 100644 (file)
--- a/mm/early_ioremap.c
+++ b/mm/early_ioremap.c
@@ -217,6 +217,13 @@ early_memremap(resource_size_t phys_addr, unsigned long size)
        return (__force void *)__early_ioremap(phys_addr, size,
                                               FIXMAP_PAGE_NORMAL);
 }
+#ifdef FIXMAP_PAGE_RO
+void __init *
+early_memremap_ro(resource_size_t phys_addr, unsigned long size)
+{
+       return (__force void *)__early_ioremap(phys_addr, size, FIXMAP_PAGE_RO);
+}
+#endif
 #else /* CONFIG_MMU */
 
 void __init __iomem *
@@ -231,6 +238,11 @@ early_memremap(resource_size_t phys_addr, unsigned long size)
 {
        return (void *)phys_addr;
 }
+void __init *
+early_memremap_ro(resource_size_t phys_addr, unsigned long size)
+{
+       return (void *)phys_addr;
+}
 
 void __init early_iounmap(void __iomem *addr, unsigned long size)
 {