diff mbox series

[RFC,04/12] riscv: Allow to dynamically define VA_BITS

Message ID 20210104195840.1593-5-alex@ghiti.fr (mailing list archive)
State New, archived
Headers show
Series Introduce sv48 support without relocable kernel | expand

Commit Message

Alexandre Ghiti Jan. 4, 2021, 7:58 p.m. UTC
With 4-level page table folding at runtime, we don't know at compile time
the size of the virtual address space so we must set VA_BITS dynamically
so that sparsemem reserves the right amount of memory for struct pages.

Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
---
 arch/riscv/Kconfig                 | 10 ----------
 arch/riscv/include/asm/pgtable.h   | 11 +++++++++--
 arch/riscv/include/asm/sparsemem.h |  6 +++++-
 3 files changed, 14 insertions(+), 13 deletions(-)

Comments

Anup Patel Jan. 5, 2021, 12:06 p.m. UTC | #1
On Tue, Jan 5, 2021 at 1:33 AM Alexandre Ghiti <alex@ghiti.fr> wrote:
>
> With 4-level page table folding at runtime, we don't know at compile time
> the size of the virtual address space so we must set VA_BITS dynamically
> so that sparsemem reserves the right amount of memory for struct pages.
>
> Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
> ---
>  arch/riscv/Kconfig                 | 10 ----------
>  arch/riscv/include/asm/pgtable.h   | 11 +++++++++--
>  arch/riscv/include/asm/sparsemem.h |  6 +++++-
>  3 files changed, 14 insertions(+), 13 deletions(-)
>
> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
> index 44377fd7860e..2979a44103be 100644
> --- a/arch/riscv/Kconfig
> +++ b/arch/riscv/Kconfig
> @@ -122,16 +122,6 @@ config ZONE_DMA32
>         bool
>         default y if 64BIT
>
> -config VA_BITS
> -       int
> -       default 32 if 32BIT
> -       default 39 if 64BIT
> -
> -config PA_BITS
> -       int
> -       default 34 if 32BIT
> -       default 56 if 64BIT
> -
>  config PAGE_OFFSET
>         hex
>         default 0xC0000000 if 32BIT && MAXPHYSMEM_2GB
> diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
> index 102b728ca146..c7973bfd65bc 100644
> --- a/arch/riscv/include/asm/pgtable.h
> +++ b/arch/riscv/include/asm/pgtable.h
> @@ -43,8 +43,14 @@
>   * struct pages to map half the virtual address space. Then
>   * position vmemmap directly below the VMALLOC region.
>   */
> +#ifdef CONFIG_64BIT
> +#define VA_BITS                39
> +#else
> +#define VA_BITS                32
> +#endif
> +
>  #define VMEMMAP_SHIFT \
> -       (CONFIG_VA_BITS - PAGE_SHIFT - 1 + STRUCT_PAGE_MAX_SHIFT)
> +       (VA_BITS - PAGE_SHIFT - 1 + STRUCT_PAGE_MAX_SHIFT)
>  #define VMEMMAP_SIZE   BIT(VMEMMAP_SHIFT)
>  #define VMEMMAP_END    (VMALLOC_START - 1)
>  #define VMEMMAP_START  (VMALLOC_START - VMEMMAP_SIZE)
> @@ -83,6 +89,7 @@
>  #endif /* CONFIG_64BIT */
>
>  #ifdef CONFIG_MMU
> +
>  /* Number of entries in the page global directory */
>  #define PTRS_PER_PGD    (PAGE_SIZE / sizeof(pgd_t))
>  /* Number of entries in the page table */
> @@ -453,7 +460,7 @@ static inline int ptep_clear_flush_young(struct vm_area_struct *vma,
>   * and give the kernel the other (upper) half.
>   */
>  #ifdef CONFIG_64BIT
> -#define KERN_VIRT_START        (-(BIT(CONFIG_VA_BITS)) + TASK_SIZE)
> +#define KERN_VIRT_START        (-(BIT(VA_BITS)) + TASK_SIZE)
>  #else
>  #define KERN_VIRT_START        FIXADDR_START
>  #endif
> diff --git a/arch/riscv/include/asm/sparsemem.h b/arch/riscv/include/asm/sparsemem.h
> index 45a7018a8118..63acaecc3374 100644
> --- a/arch/riscv/include/asm/sparsemem.h
> +++ b/arch/riscv/include/asm/sparsemem.h
> @@ -4,7 +4,11 @@
>  #define _ASM_RISCV_SPARSEMEM_H
>
>  #ifdef CONFIG_SPARSEMEM
> -#define MAX_PHYSMEM_BITS       CONFIG_PA_BITS
> +#ifdef CONFIG_64BIT
> +#define MAX_PHYSMEM_BITS       56
> +#else
> +#define MAX_PHYSMEM_BITS       34
> +#endif /* CONFIG_64BIT */
>  #define SECTION_SIZE_BITS      27
>  #endif /* CONFIG_SPARSEMEM */
>
> --
> 2.20.1
>

Looks good to me.

Reviewed-by: Anup Patel <anup@brainfault.org>

Regards,
Anup
Alexandre Ghiti Jan. 6, 2021, 6:38 a.m. UTC | #2
Le 1/5/21 à 7:06 AM, Anup Patel a écrit :
> On Tue, Jan 5, 2021 at 1:33 AM Alexandre Ghiti <alex@ghiti.fr> wrote:
>>
>> With 4-level page table folding at runtime, we don't know at compile time
>> the size of the virtual address space so we must set VA_BITS dynamically
>> so that sparsemem reserves the right amount of memory for struct pages.
>>
>> Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
>> ---
>>   arch/riscv/Kconfig                 | 10 ----------
>>   arch/riscv/include/asm/pgtable.h   | 11 +++++++++--
>>   arch/riscv/include/asm/sparsemem.h |  6 +++++-
>>   3 files changed, 14 insertions(+), 13 deletions(-)
>>
>> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
>> index 44377fd7860e..2979a44103be 100644
>> --- a/arch/riscv/Kconfig
>> +++ b/arch/riscv/Kconfig
>> @@ -122,16 +122,6 @@ config ZONE_DMA32
>>          bool
>>          default y if 64BIT
>>
>> -config VA_BITS
>> -       int
>> -       default 32 if 32BIT
>> -       default 39 if 64BIT
>> -
>> -config PA_BITS
>> -       int
>> -       default 34 if 32BIT
>> -       default 56 if 64BIT
>> -
>>   config PAGE_OFFSET
>>          hex
>>          default 0xC0000000 if 32BIT && MAXPHYSMEM_2GB
>> diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
>> index 102b728ca146..c7973bfd65bc 100644
>> --- a/arch/riscv/include/asm/pgtable.h
>> +++ b/arch/riscv/include/asm/pgtable.h
>> @@ -43,8 +43,14 @@
>>    * struct pages to map half the virtual address space. Then
>>    * position vmemmap directly below the VMALLOC region.
>>    */
>> +#ifdef CONFIG_64BIT
>> +#define VA_BITS                39
>> +#else
>> +#define VA_BITS                32
>> +#endif
>> +
>>   #define VMEMMAP_SHIFT \
>> -       (CONFIG_VA_BITS - PAGE_SHIFT - 1 + STRUCT_PAGE_MAX_SHIFT)
>> +       (VA_BITS - PAGE_SHIFT - 1 + STRUCT_PAGE_MAX_SHIFT)
>>   #define VMEMMAP_SIZE   BIT(VMEMMAP_SHIFT)
>>   #define VMEMMAP_END    (VMALLOC_START - 1)
>>   #define VMEMMAP_START  (VMALLOC_START - VMEMMAP_SIZE)
>> @@ -83,6 +89,7 @@
>>   #endif /* CONFIG_64BIT */
>>
>>   #ifdef CONFIG_MMU
>> +
>>   /* Number of entries in the page global directory */
>>   #define PTRS_PER_PGD    (PAGE_SIZE / sizeof(pgd_t))
>>   /* Number of entries in the page table */
>> @@ -453,7 +460,7 @@ static inline int ptep_clear_flush_young(struct vm_area_struct *vma,
>>    * and give the kernel the other (upper) half.
>>    */
>>   #ifdef CONFIG_64BIT
>> -#define KERN_VIRT_START        (-(BIT(CONFIG_VA_BITS)) + TASK_SIZE)
>> +#define KERN_VIRT_START        (-(BIT(VA_BITS)) + TASK_SIZE)
>>   #else
>>   #define KERN_VIRT_START        FIXADDR_START
>>   #endif
>> diff --git a/arch/riscv/include/asm/sparsemem.h b/arch/riscv/include/asm/sparsemem.h
>> index 45a7018a8118..63acaecc3374 100644
>> --- a/arch/riscv/include/asm/sparsemem.h
>> +++ b/arch/riscv/include/asm/sparsemem.h
>> @@ -4,7 +4,11 @@
>>   #define _ASM_RISCV_SPARSEMEM_H
>>
>>   #ifdef CONFIG_SPARSEMEM
>> -#define MAX_PHYSMEM_BITS       CONFIG_PA_BITS
>> +#ifdef CONFIG_64BIT
>> +#define MAX_PHYSMEM_BITS       56
>> +#else
>> +#define MAX_PHYSMEM_BITS       34
>> +#endif /* CONFIG_64BIT */
>>   #define SECTION_SIZE_BITS      27
>>   #endif /* CONFIG_SPARSEMEM */
>>
>> --
>> 2.20.1
>>
> 
> Looks good to me.
> 
> Reviewed-by: Anup Patel <anup@brainfault.org>

Thanks,

> 
> Regards,
> Anup
> 

Alex
diff mbox series

Patch

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 44377fd7860e..2979a44103be 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -122,16 +122,6 @@  config ZONE_DMA32
 	bool
 	default y if 64BIT
 
-config VA_BITS
-	int
-	default 32 if 32BIT
-	default 39 if 64BIT
-
-config PA_BITS
-	int
-	default 34 if 32BIT
-	default 56 if 64BIT
-
 config PAGE_OFFSET
 	hex
 	default 0xC0000000 if 32BIT && MAXPHYSMEM_2GB
diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index 102b728ca146..c7973bfd65bc 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -43,8 +43,14 @@ 
  * struct pages to map half the virtual address space. Then
  * position vmemmap directly below the VMALLOC region.
  */
+#ifdef CONFIG_64BIT
+#define VA_BITS		39
+#else
+#define VA_BITS		32
+#endif
+
 #define VMEMMAP_SHIFT \
-	(CONFIG_VA_BITS - PAGE_SHIFT - 1 + STRUCT_PAGE_MAX_SHIFT)
+	(VA_BITS - PAGE_SHIFT - 1 + STRUCT_PAGE_MAX_SHIFT)
 #define VMEMMAP_SIZE	BIT(VMEMMAP_SHIFT)
 #define VMEMMAP_END	(VMALLOC_START - 1)
 #define VMEMMAP_START	(VMALLOC_START - VMEMMAP_SIZE)
@@ -83,6 +89,7 @@ 
 #endif /* CONFIG_64BIT */
 
 #ifdef CONFIG_MMU
+
 /* Number of entries in the page global directory */
 #define PTRS_PER_PGD    (PAGE_SIZE / sizeof(pgd_t))
 /* Number of entries in the page table */
@@ -453,7 +460,7 @@  static inline int ptep_clear_flush_young(struct vm_area_struct *vma,
  * and give the kernel the other (upper) half.
  */
 #ifdef CONFIG_64BIT
-#define KERN_VIRT_START	(-(BIT(CONFIG_VA_BITS)) + TASK_SIZE)
+#define KERN_VIRT_START	(-(BIT(VA_BITS)) + TASK_SIZE)
 #else
 #define KERN_VIRT_START	FIXADDR_START
 #endif
diff --git a/arch/riscv/include/asm/sparsemem.h b/arch/riscv/include/asm/sparsemem.h
index 45a7018a8118..63acaecc3374 100644
--- a/arch/riscv/include/asm/sparsemem.h
+++ b/arch/riscv/include/asm/sparsemem.h
@@ -4,7 +4,11 @@ 
 #define _ASM_RISCV_SPARSEMEM_H
 
 #ifdef CONFIG_SPARSEMEM
-#define MAX_PHYSMEM_BITS	CONFIG_PA_BITS
+#ifdef CONFIG_64BIT
+#define MAX_PHYSMEM_BITS	56
+#else
+#define MAX_PHYSMEM_BITS	34
+#endif /* CONFIG_64BIT */
 #define SECTION_SIZE_BITS	27
 #endif /* CONFIG_SPARSEMEM */