[ORLinux] [PATCH] openrisc: fix PTRS_PER_PGD define

[Stefan Kristiansson]

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.kristiansson at saunalahti.fi>
---
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 37bf6a3..5630d03 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)