diff mbox series

[v3,15/34] parisc: mm: Add p?d_large() definitions

Message ID 20190227170608.27963-16-steven.price@arm.com
State New, archived
Headers show
Series Convert x86 & arm64 to use generic page walk | expand

Commit Message

Steven Price Feb. 27, 2019, 5:05 p.m. UTC
walk_page_range() is going to be allowed to walk page tables other than
those of user space. For this it needs to know when it has reached a
'leaf' entry in the page tables. This information is provided by the
p?d_large() functions/macros.

For parisc, we don't support large pages, so add stubs returning 0.

CC: "James E.J. Bottomley" <jejb@parisc-linux.org>
CC: Helge Deller <deller@gmx.de>
CC: linux-parisc@vger.kernel.org
Signed-off-by: Steven Price <steven.price@arm.com>
---
 arch/parisc/include/asm/pgtable.h | 3 +++
 1 file changed, 3 insertions(+)

Comments

Helge Deller Feb. 27, 2019, 6:54 p.m. UTC | #1
On 27.02.19 18:05, Steven Price wrote:
> walk_page_range() is going to be allowed to walk page tables other than
> those of user space. For this it needs to know when it has reached a
> 'leaf' entry in the page tables. This information is provided by the
> p?d_large() functions/macros.
> 
> For parisc, we don't support large pages, so add stubs returning 0.

We do support huge pages on parisc, but not yet on those levels.
So, you may add

Acked-by: Helge Deller <deller@gmx.de> # parisc
 
Helge

> CC: "James E.J. Bottomley" <jejb@parisc-linux.org>
> CC: Helge Deller <deller@gmx.de>
> CC: linux-parisc@vger.kernel.org
> Signed-off-by: Steven Price <steven.price@arm.com>
> ---
>  arch/parisc/include/asm/pgtable.h | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/arch/parisc/include/asm/pgtable.h b/arch/parisc/include/asm/pgtable.h
> index c7bb74e22436..1f38c85a9530 100644
> --- a/arch/parisc/include/asm/pgtable.h
> +++ b/arch/parisc/include/asm/pgtable.h
> @@ -302,6 +302,7 @@ extern unsigned long *empty_zero_page;
>  #endif
>  #define pmd_bad(x)	(!(pmd_flag(x) & PxD_FLAG_VALID))
>  #define pmd_present(x)	(pmd_flag(x) & PxD_FLAG_PRESENT)
> +#define pmd_large(x)	(0)
>  static inline void pmd_clear(pmd_t *pmd) {
>  #if CONFIG_PGTABLE_LEVELS == 3
>  	if (pmd_flag(*pmd) & PxD_FLAG_ATTACHED)
> @@ -324,6 +325,7 @@ static inline void pmd_clear(pmd_t *pmd) {
>  #define pgd_none(x)     (!pgd_val(x))
>  #define pgd_bad(x)      (!(pgd_flag(x) & PxD_FLAG_VALID))
>  #define pgd_present(x)  (pgd_flag(x) & PxD_FLAG_PRESENT)
> +#define pgd_large(x)	(0)
>  static inline void pgd_clear(pgd_t *pgd) {
>  #if CONFIG_PGTABLE_LEVELS == 3
>  	if(pgd_flag(*pgd) & PxD_FLAG_ATTACHED)
> @@ -342,6 +344,7 @@ static inline void pgd_clear(pgd_t *pgd) {
>  static inline int pgd_none(pgd_t pgd)		{ return 0; }
>  static inline int pgd_bad(pgd_t pgd)		{ return 0; }
>  static inline int pgd_present(pgd_t pgd)	{ return 1; }
> +static inline int pgd_large(pgd_t pgd)		{ return 0; }
>  static inline void pgd_clear(pgd_t * pgdp)	{ }
>  #endif
>  
>
Kirill A. Shutemov March 1, 2019, 10:12 p.m. UTC | #2
On Wed, Feb 27, 2019 at 07:54:22PM +0100, Helge Deller wrote:
> On 27.02.19 18:05, Steven Price wrote:
> > walk_page_range() is going to be allowed to walk page tables other than
> > those of user space. For this it needs to know when it has reached a
> > 'leaf' entry in the page tables. This information is provided by the
> > p?d_large() functions/macros.
> > 
> > For parisc, we don't support large pages, so add stubs returning 0.
> 
> We do support huge pages on parisc, but not yet on those levels.

Just curious, what level do parisc supports huge pages on?
AFAICS, it can have 2- or 3- level paging and the patch defines helpers
for two level: pgd and pmd. Hm?
Helge Deller March 5, 2019, 9:45 p.m. UTC | #3
On 01.03.19 23:12, Kirill A. Shutemov wrote:
> On Wed, Feb 27, 2019 at 07:54:22PM +0100, Helge Deller wrote:
>> On 27.02.19 18:05, Steven Price wrote:
>>> walk_page_range() is going to be allowed to walk page tables other than
>>> those of user space. For this it needs to know when it has reached a
>>> 'leaf' entry in the page tables. This information is provided by the
>>> p?d_large() functions/macros.
>>>
>>> For parisc, we don't support large pages, so add stubs returning 0.
>>
>> We do support huge pages on parisc, but not yet on those levels.
> 
> Just curious, what level do parisc supports huge pages on?
> AFAICS, it can have 2- or 3- level paging and the patch defines helpers
> for two level: pgd and pmd. Hm?

You are correct.
My comment was misleading and meant to say that we do support generic
huge pages for applications.

Helge
diff mbox series

Patch

diff --git a/arch/parisc/include/asm/pgtable.h b/arch/parisc/include/asm/pgtable.h
index c7bb74e22436..1f38c85a9530 100644
--- a/arch/parisc/include/asm/pgtable.h
+++ b/arch/parisc/include/asm/pgtable.h
@@ -302,6 +302,7 @@  extern unsigned long *empty_zero_page;
 #endif
 #define pmd_bad(x)	(!(pmd_flag(x) & PxD_FLAG_VALID))
 #define pmd_present(x)	(pmd_flag(x) & PxD_FLAG_PRESENT)
+#define pmd_large(x)	(0)
 static inline void pmd_clear(pmd_t *pmd) {
 #if CONFIG_PGTABLE_LEVELS == 3
 	if (pmd_flag(*pmd) & PxD_FLAG_ATTACHED)
@@ -324,6 +325,7 @@  static inline void pmd_clear(pmd_t *pmd) {
 #define pgd_none(x)     (!pgd_val(x))
 #define pgd_bad(x)      (!(pgd_flag(x) & PxD_FLAG_VALID))
 #define pgd_present(x)  (pgd_flag(x) & PxD_FLAG_PRESENT)
+#define pgd_large(x)	(0)
 static inline void pgd_clear(pgd_t *pgd) {
 #if CONFIG_PGTABLE_LEVELS == 3
 	if(pgd_flag(*pgd) & PxD_FLAG_ATTACHED)
@@ -342,6 +344,7 @@  static inline void pgd_clear(pgd_t *pgd) {
 static inline int pgd_none(pgd_t pgd)		{ return 0; }
 static inline int pgd_bad(pgd_t pgd)		{ return 0; }
 static inline int pgd_present(pgd_t pgd)	{ return 1; }
+static inline int pgd_large(pgd_t pgd)		{ return 0; }
 static inline void pgd_clear(pgd_t * pgdp)	{ }
 #endif