Re: [PATCH 2/7] openrisc: fix PTRS_PER_PGD define

[Jonas Bonn]

On 09/16/2016 04:43 PM, Stafford Horne wrote:

From: 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 
Signed-off-by: Stafford Horne 

Acked-by: Jonas Bonn 


---
  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)

Re: [PATCH 2/7] openrisc: fix PTRS_PER_PGD define

[Jonas Bonn]

On 09/16/2016 04:43 PM, Stafford Horne wrote:

From: 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 
Signed-off-by: Stafford Horne 

Acked-by: Jonas Bonn 


---
  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)