ARM: factor out allocation routine from __create_mapping()

To allow __create_mapping() to be used for populating UEFI Runtime
Services page tables, factor out the allocation routine 'early_alloc'
and pass it down as a function pointer into alloc_init_[pud|pmd|pte].
This way, new users of __create_mapping() can supply another allocation
function.

Tested-by: Ryan Harkin <ryan.harkin@linaro.org>
Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

1 files changed, 23 insertions, 11 deletions

diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index 3100de92148b..87dc49dbe231 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -724,21 +724,30 @@ static void __init *early_alloc(unsigned long sz)
         return early_alloc_aligned(sz, sz);
 }
 
-static pte_t * __init early_pte_alloc(pmd_t *pmd, unsigned long addr, unsigned long prot)
+static pte_t * __init pte_alloc(pmd_t *pmd, unsigned long addr,
+                                unsigned long prot,
+                                void *(*alloc)(unsigned long sz))
 {
         if (pmd_none(*pmd)) {
-                pte_t *pte = early_alloc(PTE_HWTABLE_OFF + PTE_HWTABLE_SIZE);
+                pte_t *pte = alloc(PTE_HWTABLE_OFF + PTE_HWTABLE_SIZE);
                 __pmd_populate(pmd, __pa(pte), prot);
         }
         BUG_ON(pmd_bad(*pmd));
         return pte_offset_kernel(pmd, addr);
 }
 
+static pte_t * __init early_pte_alloc(pmd_t *pmd, unsigned long addr,
+                                      unsigned long prot)
+{
+        return pte_alloc(pmd, addr, prot, early_alloc);
+}
+
 static void __init alloc_init_pte(pmd_t *pmd, unsigned long addr,
                                   unsigned long end, unsigned long pfn,
-                                  const struct mem_type *type)
+                                  const struct mem_type *type,
+                                  void *(*alloc)(unsigned long sz))
 {
-        pte_t *pte = early_pte_alloc(pmd, addr, type->prot_l1);
+        pte_t *pte = pte_alloc(pmd, addr, type->prot_l1, alloc);
         do {
                 set_pte_ext(pte, pfn_pte(pfn, __pgprot(type->prot_pte)), 0);
                 pfn++;
@@ -774,7 +783,8 @@ static void __init __map_init_section(pmd_t *pmd, unsigned long addr,
 
 static void __init alloc_init_pmd(pud_t *pud, unsigned long addr,
                                       unsigned long end, phys_addr_t phys,
-                                      const struct mem_type *type)
+                                      const struct mem_type *type,
+                                      void *(*alloc)(unsigned long sz))
 {
         pmd_t *pmd = pmd_offset(pud, addr);
         unsigned long next;
@@ -795,7 +805,7 @@ static void __init alloc_init_pmd(pud_t *pud, unsigned long addr,
                         __map_init_section(pmd, addr, next, phys, type);
                 } else {
                         alloc_init_pte(pmd, addr, next,
-                                                __phys_to_pfn(phys), type);
+                                       __phys_to_pfn(phys), type, alloc);
                 }
 
                 phys += next - addr;
@@ -805,14 +815,15 @@ static void __init alloc_init_pmd(pud_t *pud, unsigned long addr,
 
 static void __init alloc_init_pud(pgd_t *pgd, unsigned long addr,
                                   unsigned long end, phys_addr_t phys,
-                                  const struct mem_type *type)
+                                  const struct mem_type *type,
+                                  void *(*alloc)(unsigned long sz))
 {
         pud_t *pud = pud_offset(pgd, addr);
         unsigned long next;
 
         do {
                 next = pud_addr_end(addr, end);
-                alloc_init_pmd(pud, addr, next, phys, type);
+                alloc_init_pmd(pud, addr, next, phys, type, alloc);
                 phys += next - addr;
         } while (pud++, addr = next, addr != end);
 }
@@ -877,7 +888,8 @@ static void __init create_36bit_mapping(struct mm_struct *mm,
 }
 #endif  /* !CONFIG_ARM_LPAE */
 
-static void __init __create_mapping(struct mm_struct *mm, struct map_desc *md)
+static void __init __create_mapping(struct mm_struct *mm, struct map_desc *md,
+                                    void *(*alloc)(unsigned long sz))
 {
         unsigned long addr, length, end;
         phys_addr_t phys;
@@ -911,7 +923,7 @@ static void __init __create_mapping(struct mm_struct *mm, struct map_desc *md)
         do {
                 unsigned long next = pgd_addr_end(addr, end);
 
-                alloc_init_pud(pgd, addr, next, phys, type);
+                alloc_init_pud(pgd, addr, next, phys, type, alloc);
 
                 phys += next - addr;
                 addr = next;
@@ -940,7 +952,7 @@ static void __init create_mapping(struct map_desc *md)
                         (long long)__pfn_to_phys((u64)md->pfn), md->virtual);
         }
 
-        __create_mapping(&init_mm, md);
+        __create_mapping(&init_mm, md, early_alloc);
 }
 
 /*