2023-08-09 03:48:08

by Song Shuai

[permalink] [raw]
Subject: [PATCH] riscv: mm: Update the comment of CONFIG_PAGE_OFFSET

From: Song Shuai <[email protected]>

Since the commit 011f09d12052 set sv57 as default for CONFIG_64BIT,
the comment of CONFIG_PAGE_OFFSET should be updated too.

Fixes: 011f09d12052 ("riscv: mm: Set sv57 on defaultly")
Signed-off-by: Song Shuai <[email protected]>
---
arch/riscv/include/asm/page.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/riscv/include/asm/page.h b/arch/riscv/include/asm/page.h
index b55ba20903ec..53c00164c042 100644
--- a/arch/riscv/include/asm/page.h
+++ b/arch/riscv/include/asm/page.h
@@ -33,8 +33,8 @@
#define PAGE_OFFSET _AC(CONFIG_PAGE_OFFSET, UL)
#endif
/*
- * By default, CONFIG_PAGE_OFFSET value corresponds to SV48 address space so
- * define the PAGE_OFFSET value for SV39.
+ * By default, CONFIG_PAGE_OFFSET value corresponds to SV57 address space so
+ * define the PAGE_OFFSET value for SV48 and SV39.
*/
#define PAGE_OFFSET_L4 _AC(0xffffaf8000000000, UL)
#define PAGE_OFFSET_L3 _AC(0xffffffd800000000, UL)
--
2.20.1



2023-09-14 05:00:02

by Guo Ren

[permalink] [raw]
Subject: Re: [PATCH] riscv: mm: Update the comment of CONFIG_PAGE_OFFSET

On Wed, Aug 9, 2023 at 11:11 AM Song Shuai <[email protected]> wrote:
>
> From: Song Shuai <[email protected]>
>
> Since the commit 011f09d12052 set sv57 as default for CONFIG_64BIT,
> the comment of CONFIG_PAGE_OFFSET should be updated too.
>
> Fixes: 011f09d12052 ("riscv: mm: Set sv57 on defaultly")
> Signed-off-by: Song Shuai <[email protected]>
> ---
> arch/riscv/include/asm/page.h | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/riscv/include/asm/page.h b/arch/riscv/include/asm/page.h
> index b55ba20903ec..53c00164c042 100644
> --- a/arch/riscv/include/asm/page.h
> +++ b/arch/riscv/include/asm/page.h
> @@ -33,8 +33,8 @@
> #define PAGE_OFFSET _AC(CONFIG_PAGE_OFFSET, UL)
Why not remove CONFIG_PAGE_OFFSET and define PAGE_OFFSET_L2 ?

> #endif
> /*
> - * By default, CONFIG_PAGE_OFFSET value corresponds to SV48 address space so
> - * define the PAGE_OFFSET value for SV39.
> + * By default, CONFIG_PAGE_OFFSET value corresponds to SV57 address space so
> + * define the PAGE_OFFSET value for SV48 and SV39.
> */
> #define PAGE_OFFSET_L4 _AC(0xffffaf8000000000, UL)
> #define PAGE_OFFSET_L3 _AC(0xffffffd800000000, UL)
> --
> 2.20.1
>


--
Best Regards
Guo Ren

2023-09-14 06:53:51

by Song Shuai

[permalink] [raw]
Subject: Re: [PATCH] riscv: mm: Update the comment of CONFIG_PAGE_OFFSET



在 2023/9/14 12:59, Guo Ren 写道:
> On Wed, Aug 9, 2023 at 11:11 AM Song Shuai <[email protected]> wrote:
>>
>> From: Song Shuai <[email protected]>
>>
>> Since the commit 011f09d12052 set sv57 as default for CONFIG_64BIT,
>> the comment of CONFIG_PAGE_OFFSET should be updated too.
>>
>> Fixes: 011f09d12052 ("riscv: mm: Set sv57 on defaultly")
>> Signed-off-by: Song Shuai <[email protected]>
>> ---
>> arch/riscv/include/asm/page.h | 4 ++--
>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/arch/riscv/include/asm/page.h b/arch/riscv/include/asm/page.h
>> index b55ba20903ec..53c00164c042 100644
>> --- a/arch/riscv/include/asm/page.h
>> +++ b/arch/riscv/include/asm/page.h
>> @@ -33,8 +33,8 @@
>> #define PAGE_OFFSET _AC(CONFIG_PAGE_OFFSET, UL)
> Why not remove CONFIG_PAGE_OFFSET and define PAGE_OFFSET_L2 ?
>
CONFIG_PAGE_OFFSET holds the first memory address regarding the
different CONFIGs (MMU,32BIT,64BIT).

As for 64BIT, it actually represents "PAGE_OFFSET_L5" for Sv57 page mode
defaultly. And the real page mode may be downgraded from kernel cmdline
or restricted by the hardware, so the PAGE_OFFSET_L3/L4 was defined to
set the real PAGE_OFFSET.

IIUC, the "PAGE_OFFSET_L2" you specified might be the "PAGE_OFFSET_L5" I
previously mentioned,
If not, the PAGE_OFFSET_L2 semantically means the page offset for
32BIT's default Sv32 page mode,and it has already been held in
CONFIG_PAGE_OFFSET too.

So IMO there is no need to touch CONFIG_PAGE_OFFSET in this context.

Please correct me If I'm wrong.
>> #endif
>> /*
>> - * By default, CONFIG_PAGE_OFFSET value corresponds to SV48 address space so
>> - * define the PAGE_OFFSET value for SV39.
>> + * By default, CONFIG_PAGE_OFFSET value corresponds to SV57 address space so
>> + * define the PAGE_OFFSET value for SV48 and SV39.
>> */
>> #define PAGE_OFFSET_L4 _AC(0xffffaf8000000000, UL)
>> #define PAGE_OFFSET_L3 _AC(0xffffffd800000000, UL)
>> --
>> 2.20.1
>>
>
>

--
Thanks
Song Shuai

2023-09-14 13:26:11

by Song Shuai

[permalink] [raw]
Subject: Re: [PATCH] riscv: mm: Update the comment of CONFIG_PAGE_OFFSET

Song Shuai <[email protected]> 于2023年8月9日周三 03:12写道:
>
> From: Song Shuai <[email protected]>
>
> Since the commit 011f09d12052 set sv57 as default for CONFIG_64BIT,
> the comment of CONFIG_PAGE_OFFSET should be updated too.
>
> Fixes: 011f09d12052 ("riscv: mm: Set sv57 on defaultly")
> Signed-off-by: Song Shuai <[email protected]>
> ---
> arch/riscv/include/asm/page.h | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/riscv/include/asm/page.h b/arch/riscv/include/asm/page.h
> index b55ba20903ec..53c00164c042 100644
> --- a/arch/riscv/include/asm/page.h
> +++ b/arch/riscv/include/asm/page.h
> @@ -33,8 +33,8 @@
> #define PAGE_OFFSET _AC(CONFIG_PAGE_OFFSET, UL)
> #endif
> /*
> - * By default, CONFIG_PAGE_OFFSET value corresponds to SV48 address space so
> - * define the PAGE_OFFSET value for SV39.
> + * By default, CONFIG_PAGE_OFFSET value corresponds to SV57 address space so
> + * define the PAGE_OFFSET value for SV48 and SV39.
> */
> #define PAGE_OFFSET_L4 _AC(0xffffaf8000000000, UL)
> #define PAGE_OFFSET_L3 _AC(0xffffffd800000000, UL)
> --
> 2.20.1
>
Ping...

--
Thanks,
Song

Subject: Re: [PATCH] riscv: mm: Update the comment of CONFIG_PAGE_OFFSET

Hello:

This patch was applied to riscv/linux.git (for-next)
by Palmer Dabbelt <[email protected]>:

On Wed, 9 Aug 2023 11:10:23 +0800 you wrote:
> From: Song Shuai <[email protected]>
>
> Since the commit 011f09d12052 set sv57 as default for CONFIG_64BIT,
> the comment of CONFIG_PAGE_OFFSET should be updated too.
>
> Fixes: 011f09d12052 ("riscv: mm: Set sv57 on defaultly")
> Signed-off-by: Song Shuai <[email protected]>
>
> [...]

Here is the summary with links:
- riscv: mm: Update the comment of CONFIG_PAGE_OFFSET
https://git.kernel.org/riscv/c/d42469b616b1

You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html


2023-10-29 13:53:39

by Guo Ren

[permalink] [raw]
Subject: Re: [PATCH] riscv: mm: Update the comment of CONFIG_PAGE_OFFSET

On Thu, Sep 14, 2023 at 2:52 PM Song Shuai <[email protected]> wrote:
>
>
>
> 在 2023/9/14 12:59, Guo Ren 写道:
> > On Wed, Aug 9, 2023 at 11:11 AM Song Shuai <[email protected]> wrote:
> >>
> >> From: Song Shuai <[email protected]>
> >>
> >> Since the commit 011f09d12052 set sv57 as default for CONFIG_64BIT,
> >> the comment of CONFIG_PAGE_OFFSET should be updated too.
> >>
> >> Fixes: 011f09d12052 ("riscv: mm: Set sv57 on defaultly")
> >> Signed-off-by: Song Shuai <[email protected]>
> >> ---
> >> arch/riscv/include/asm/page.h | 4 ++--
> >> 1 file changed, 2 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/arch/riscv/include/asm/page.h b/arch/riscv/include/asm/page.h
> >> index b55ba20903ec..53c00164c042 100644
> >> --- a/arch/riscv/include/asm/page.h
> >> +++ b/arch/riscv/include/asm/page.h
> >> @@ -33,8 +33,8 @@
> >> #define PAGE_OFFSET _AC(CONFIG_PAGE_OFFSET, UL)
> > Why not remove CONFIG_PAGE_OFFSET and define PAGE_OFFSET_L2 ?
> >
> CONFIG_PAGE_OFFSET holds the first memory address regarding the
> different CONFIGs (MMU,32BIT,64BIT).
>
> As for 64BIT, it actually represents "PAGE_OFFSET_L5" for Sv57 page mode
> defaultly. And the real page mode may be downgraded from kernel cmdline
> or restricted by the hardware, so the PAGE_OFFSET_L3/L4 was defined to
> set the real PAGE_OFFSET.
>
> IIUC, the "PAGE_OFFSET_L2" you specified might be the "PAGE_OFFSET_L5" I
> previously mentioned,
> If not, the PAGE_OFFSET_L2 semantically means the page offset for
> 32BIT's default Sv32 page mode,and it has already been held in
> CONFIG_PAGE_OFFSET too.
>
> So IMO there is no need to touch CONFIG_PAGE_OFFSET in this context.

I mean:

#define PAGE_OFFSET_L5 _AC(0xff60000000000000, UL)
#define PAGE_OFFSET_L4 _AC(0xffffaf8000000000, UL)
#define PAGE_OFFSET_L3 _AC(0xffffffd800000000, UL)
#define PAGE_OFFSET_L2 _AC(0xC0000000)

#ifdef CONFIG_MMU
#ifdef CONFIG_64BIT
#define PAGE_OFFSET kernel_map.page_offset
#else /* CONFIG_64BIT */
#define PAGE_OFFSET PAGE_OFFSET_L2
#endif /* CONFIG_64BIT */
#else /* CONFIG_MMU */
#define PAGE_OFFSET 0x80000000
#endif /* CONFIG_MMU */

kernel_map.page_offset = _AC(PAGE_OFFSET_L5, UL);

The kernel_map.page_offset is no use to CONFIG_32BIT.

Remove the CONFIG_PAGE_OFFSET, and put all PAGE_OFFSET* together to
ease maintenance and reading.



>
> Please correct me If I'm wrong.
> >> #endif
> >> /*
> >> - * By default, CONFIG_PAGE_OFFSET value corresponds to SV48 address space so
> >> - * define the PAGE_OFFSET value for SV39.
> >> + * By default, CONFIG_PAGE_OFFSET value corresponds to SV57 address space so
> >> + * define the PAGE_OFFSET value for SV48 and SV39.
> >> */
> >> #define PAGE_OFFSET_L4 _AC(0xffffaf8000000000, UL)
> >> #define PAGE_OFFSET_L3 _AC(0xffffffd800000000, UL)
> >> --
> >> 2.20.1
> >>
> >
> >
>
> --
> Thanks
> Song Shuai
>


--
Best Regards
Guo Ren