On 09/16/2016 04:43 PM, Stafford Horne wrote:
From: Stefan Kristiansson <stefan.kristians...@saunalahti.fi>

On OpenRISC, with its 8k pages, PAGE_SHIFT is defined to be 13.
That makes the expression (1UL << (PAGE_SHIFT-2)) evaluate
to 2048.
The correct value for PTRS_PER_PGD should be 256.

Correcting the PTRS_PER_PGD define unveiled a bug in map_ram(),
where PTRS_PER_PGD was used when the intent was to iterate
over a set of page table entries.
This patch corrects that issue as well.

Signed-off-by: Stefan Kristiansson <stefan.kristians...@saunalahti.fi>
Signed-off-by: Stafford Horne <sho...@gmail.com>
Acked-by: Jonas Bonn <jo...@southpole.se>

---
  arch/openrisc/include/asm/pgtable.h | 2 +-
  arch/openrisc/mm/init.c             | 2 +-
  2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/openrisc/include/asm/pgtable.h 
b/arch/openrisc/include/asm/pgtable.h
index 69c7df0..3567aa7 100644
--- a/arch/openrisc/include/asm/pgtable.h
+++ b/arch/openrisc/include/asm/pgtable.h
@@ -69,7 +69,7 @@ extern void paging_init(void);
   */
  #define PTRS_PER_PTE  (1UL << (PAGE_SHIFT-2))
-#define PTRS_PER_PGD (1UL << (PAGE_SHIFT-2))
+#define PTRS_PER_PGD   (1UL << (32-PGDIR_SHIFT))
/* calculate how many PGD entries a user-level program can use
   * the first mappable virtual address is 0
diff --git a/arch/openrisc/mm/init.c b/arch/openrisc/mm/init.c
index 7f94652..b782ce9 100644
--- a/arch/openrisc/mm/init.c
+++ b/arch/openrisc/mm/init.c
@@ -110,7 +110,7 @@ static void __init map_ram(void)
                        set_pmd(pme, __pmd(_KERNPG_TABLE + __pa(pte)));
/* Fill the newly allocated page with PTE'S */
-                       for (j = 0; p < e && j < PTRS_PER_PGD;
+                       for (j = 0; p < e && j < PTRS_PER_PTE;
                             v += PAGE_SIZE, p += PAGE_SIZE, j++, pte++) {
                                if (v >= (u32) _e_kernel_ro ||
                                    v < (u32) _s_kernel_ro)

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