Re: [RFC][PATCH v3 05/22] mm, tile: add gfp flags variant of pmd and pte allocations

[Prasad Joshi <prasadjoshi124@gmail.com>]

- Added function __pte_alloc_one() which is very similar to pte_alloc_one(),
  but also accepts an additional gfp_t allocation flag.

- The pte_alloc_one() function calls __pte_alloc_one().

- Added function __pte_alloc_one_kernel() to accept and then pass the
  allocation flag to __pte_alloc_one().

- The function pte_alloc_one_kernel() calls __pte_alloc_one_kernel().

- Added function __pmd_alloc_one to allocation pmd entries using the
  specified allocation flag. It works by passing the allocation flag
  to __pte_alloc_one().

- changes help in fixing the Bug 30702

Signed-off-by: Prasad Joshi <prasadjoshi124@gmail.com>
Signed-off-by: Anand Mitra <mitra@kqinfotech.com>
---
 arch/tile/include/asm/pgalloc.h |   13 ++++++++++++-
 arch/tile/mm/pgtable.c          |   10 ++++++++--
 2 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/arch/tile/include/asm/pgalloc.h b/arch/tile/include/asm/pgalloc.h
index cf52791..2dcad88 100644
--- a/arch/tile/include/asm/pgalloc.h
+++ b/arch/tile/include/asm/pgalloc.h
@@ -69,14 +69,23 @@ extern pgd_t *pgd_alloc(struct mm_struct *mm);
 extern void pgd_free(struct mm_struct *mm, pgd_t *pgd);
 
 extern pgtable_t pte_alloc_one(struct mm_struct *mm, unsigned long address);
+extern pgtable_t __pte_alloc_one(struct mm_struct *, unsigned long, gfp_t);
+
 extern void pte_free(struct mm_struct *mm, struct page *pte);
 
 #define pmd_pgtable(pmd) pmd_page(pmd)
 
 static inline pte_t *
+__pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address, 
+		gfp_t gfp_mask)
+{
+	return pfn_to_kaddr(page_to_pfn(__pte_alloc_one(mm, address, gfp_mask)));
+}
+
+static inline pte_t *
 pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
 {
-	return pfn_to_kaddr(page_to_pfn(pte_alloc_one(mm, address)));
+	return __pte_alloc_one_kernel(mm, address, GFP_KERNEL | __GFP_REPEAT);
 }
 
 static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
@@ -108,6 +117,8 @@ void shatter_pmd(pmd_t *pmd);
 #define L1_USER_PGTABLE_ORDER L2_USER_PGTABLE_ORDER
 #define pud_populate(mm, pud, pmd) \
   pmd_populate_kernel((mm), (pmd_t *)(pud), (pte_t *)(pmd))
+#define __pmd_alloc_one(mm, addr, mask) \
+  ((pmd_t *)page_to_virt(__pte_alloc_one((mm), (addr), (mask))))
 #define pmd_alloc_one(mm, addr) \
   ((pmd_t *)page_to_virt(pte_alloc_one((mm), (addr))))
 #define pmd_free(mm, pmdp) \
diff --git a/arch/tile/mm/pgtable.c b/arch/tile/mm/pgtable.c
index 1f5430c..34ee920 100644
--- a/arch/tile/mm/pgtable.c
+++ b/arch/tile/mm/pgtable.c
@@ -218,9 +218,10 @@ void pgd_free(struct mm_struct *mm, pgd_t *pgd)
 
 #define L2_USER_PGTABLE_PAGES (1 << L2_USER_PGTABLE_ORDER)
 
-struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address)
+struct page *
+__pte_alloc_one(struct mm_struct *mm, unsigned long address, gfp_t gfp_mask)
 {
-	gfp_t flags = GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO|__GFP_COMP;
+	gfp_t flags = gfp_mask | __GFP_ZERO | __GFP_COMP;
 	struct page *p;
 
 #ifdef CONFIG_HIGHPTE
@@ -235,6 +236,11 @@ struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address)
 	return p;
 }
 
+struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address)
+{
+	return __pte_alloc_one(mm, address, GFP_KERNEL);
+}
+
 /*
  * Free page immediately (used in __pte_alloc if we raced with another
  * process).  We have to correct whatever pte_alloc_one() did before
-- 
1.7.0.4