1 files changed, 36 insertions, 3 deletions

diff --git a/lib/ioremap.c b/lib/ioremap.c
index a3e14ce92a56..4bb30206b942 100644
--- a/lib/ioremap.c
+++ b/lib/ioremap.c
@@ -14,6 +14,7 @@
 #include <asm/pgtable.h>
 
 #ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
+static int __read_mostly ioremap_p4d_capable;
 static int __read_mostly ioremap_pud_capable;
 static int __read_mostly ioremap_pmd_capable;
 static int __read_mostly ioremap_huge_disabled;
@@ -35,6 +36,11 @@ void __init ioremap_huge_init(void)
         }
 }
 
+static inline int ioremap_p4d_enabled(void)
+{
+        return ioremap_p4d_capable;
+}
+
 static inline int ioremap_pud_enabled(void)
 {
         return ioremap_pud_capable;
@@ -46,6 +52,7 @@ static inline int ioremap_pmd_enabled(void)
 }
 
 #else   /* !CONFIG_HAVE_ARCH_HUGE_VMAP */
+static inline int ioremap_p4d_enabled(void) { return 0; }
 static inline int ioremap_pud_enabled(void) { return 0; }
 static inline int ioremap_pmd_enabled(void) { return 0; }
 #endif  /* CONFIG_HAVE_ARCH_HUGE_VMAP */
@@ -94,14 +101,14 @@ static inline int ioremap_pmd_range(pud_t *pud, unsigned long addr,
         return 0;
 }
 
-static inline int ioremap_pud_range(pgd_t *pgd, unsigned long addr,
+static inline int ioremap_pud_range(p4d_t *p4d, unsigned long addr,
                 unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
 {
         pud_t *pud;
         unsigned long next;
 
         phys_addr -= addr;
-        pud = pud_alloc(&init_mm, pgd, addr);
+        pud = pud_alloc(&init_mm, p4d, addr);
         if (!pud)
                 return -ENOMEM;
         do {
@@ -120,6 +127,32 @@ static inline int ioremap_pud_range(pgd_t *pgd, unsigned long addr,
         return 0;
 }
 
+static inline int ioremap_p4d_range(pgd_t *pgd, unsigned long addr,
+                unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
+{
+        p4d_t *p4d;
+        unsigned long next;
+
+        phys_addr -= addr;
+        p4d = p4d_alloc(&init_mm, pgd, addr);
+        if (!p4d)
+                return -ENOMEM;
+        do {
+                next = p4d_addr_end(addr, end);
+
+                if (ioremap_p4d_enabled() &&
+                    ((next - addr) == P4D_SIZE) &&
+                    IS_ALIGNED(phys_addr + addr, P4D_SIZE)) {
+                        if (p4d_set_huge(p4d, phys_addr + addr, prot))
+                                continue;
+                }
+
+                if (ioremap_pud_range(p4d, addr, next, phys_addr + addr, prot))
+                        return -ENOMEM;
+        } while (p4d++, addr = next, addr != end);
+        return 0;
+}
+
 int ioremap_page_range(unsigned long addr,
                        unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
 {
@@ -135,7 +168,7 @@ int ioremap_page_range(unsigned long addr,
         pgd = pgd_offset_k(addr);
         do {
                 next = pgd_addr_end(addr, end);
-                err = ioremap_pud_range(pgd, addr, next, phys_addr+addr, prot);
+                err = ioremap_p4d_range(pgd, addr, next, phys_addr+addr, prot);
                 if (err)
                         break;
         } while (pgd++, addr = next, addr != end);