On 2/25/22 2:22 PM, Anshuman Khandual wrote:
>
> On 2/25/22 7:01 AM, Dinh Nguyen wrote:
>> Hi Anshuman,
>>
>> On 2/13/22 20:30, Anshuman Khandual wrote:
>>> This defines and exports a platform specific custom vm_get_page_prot() via
>>> subscribing ARCH_HAS_VM_GET_PAGE_PROT. Subsequently all __SXXX and __PXXX
>>> macros can be dropped which are no longer needed.
>>>
>>> Cc: Dinh Nguyen <dinguyen@xxxxxxxxxx>
>>> Cc: linux-kernel@xxxxxxxxxxxxxxx
>>> Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
>>> Acked-by: Dinh Nguyen <dinguyen@xxxxxxxxxx>
>>> ---
>>> arch/nios2/Kconfig | 1 +
>>> arch/nios2/include/asm/pgtable.h | 16 ------------
>>> arch/nios2/mm/init.c | 45 ++++++++++++++++++++++++++++++++
>>> 3 files changed, 46 insertions(+), 16 deletions(-)
>>>
>>> diff --git a/arch/nios2/Kconfig b/arch/nios2/Kconfig
>>> index 33fd06f5fa41..85a58a357a3b 100644
>>> --- a/arch/nios2/Kconfig
>>> +++ b/arch/nios2/Kconfig
>>> @@ -6,6 +6,7 @@ config NIOS2
>>> select ARCH_HAS_SYNC_DMA_FOR_CPU
>>> select ARCH_HAS_SYNC_DMA_FOR_DEVICE
>>> select ARCH_HAS_DMA_SET_UNCACHED
>>> + select ARCH_HAS_VM_GET_PAGE_PROT
>>> select ARCH_NO_SWAP
>>> select COMMON_CLK
>>> select TIMER_OF
>>> diff --git a/arch/nios2/include/asm/pgtable.h b/arch/nios2/include/asm/pgtable.h
>>> index 4a995fa628ee..2678dad58a63 100644
>>> --- a/arch/nios2/include/asm/pgtable.h
>>> +++ b/arch/nios2/include/asm/pgtable.h
>>> @@ -40,24 +40,8 @@ struct mm_struct;
>>> */
>>> /* Remove W bit on private pages for COW support */
>>> -#define __P000 MKP(0, 0, 0)
>>> -#define __P001 MKP(0, 0, 1)
>>> -#define __P010 MKP(0, 0, 0) /* COW */
>>> -#define __P011 MKP(0, 0, 1) /* COW */
>>> -#define __P100 MKP(1, 0, 0)
>>> -#define __P101 MKP(1, 0, 1)
>>> -#define __P110 MKP(1, 0, 0) /* COW */
>>> -#define __P111 MKP(1, 0, 1) /* COW */
>>> /* Shared pages can have exact HW mapping */
>>> -#define __S000 MKP(0, 0, 0)
>>> -#define __S001 MKP(0, 0, 1)
>>> -#define __S010 MKP(0, 1, 0)
>>> -#define __S011 MKP(0, 1, 1)
>>> -#define __S100 MKP(1, 0, 0)
>>> -#define __S101 MKP(1, 0, 1)
>>> -#define __S110 MKP(1, 1, 0)
>>> -#define __S111 MKP(1, 1, 1)
>>> /* Used all over the kernel */
>>> #define PAGE_KERNEL __pgprot(_PAGE_PRESENT | _PAGE_CACHED | _PAGE_READ | \
>>> diff --git a/arch/nios2/mm/init.c b/arch/nios2/mm/init.c
>>> index 613fcaa5988a..311b2146a248 100644
>>> --- a/arch/nios2/mm/init.c
>>> +++ b/arch/nios2/mm/init.c
>>> @@ -124,3 +124,48 @@ const char *arch_vma_name(struct vm_area_struct *vma)
>>> {
>>> return (vma->vm_start == KUSER_BASE) ? "[kuser]" : NULL;
>>> }
>>> +
>>> +pgprot_t vm_get_page_prot(unsigned long vm_flags)
>>> +{
>>> + switch (vm_flags & (VM_READ | VM_WRITE | VM_EXEC | VM_SHARED)) {
>>> + case VM_NONE:
>>> + return MKP(0, 0, 0);
>>> + case VM_READ:
>>> + return MKP(0, 0, 1);
>>> + /* COW */
>>> + case VM_WRITE:
>>> + return MKP(0, 0, 0);
>>> + /* COW */
>>> + case VM_WRITE | VM_READ:
>>> + return MKP(0, 0, 1);
>>> + case VM_EXEC:
>>> + return MKP(1, 0, 0);
>>> + case VM_EXEC | VM_READ:
>>> + return MKP(1, 0, 1);
>>> + /* COW */
>>> + case VM_EXEC | VM_WRITE:
>>> + return MKP(1, 0, 0);
>>> + /* COW */
>>> + case VM_EXEC | VM_WRITE | VM_READ:
>>> + return MKP(1, 0, 1);
>>> + case VM_SHARED:
>>> + return MKP(0, 0, 0);
>>> + case VM_SHARED | VM_READ:
>>> + return MKP(0, 0, 1);
>>> + case VM_SHARED | VM_WRITE:
>>> + return MKP(0, 1, 0);
>>> + case VM_SHARED | VM_WRITE | VM_READ:
>>> + return MKP(0, 1, 1);
>>> + case VM_SHARED | VM_EXEC:
>>> + return MKP(1, 0, 0);
>>> + case VM_SHARED | VM_EXEC | VM_READ:
>>> + return MKP(1, 0, 1);
>>> + case VM_SHARED | VM_EXEC | VM_WRITE:
>>> + return MKP(1, 1, 0);
>>> + case VM_SHARED | VM_EXEC | VM_WRITE | VM_READ:
>>> + return MKP(1, 1, 1);
>>> + default:
>>> + BUILD_BUG();
>>> + }
>>> +}
>>> +EXPORT_SYMBOL(vm_get_page_prot);
>> I'm getting this compile error after applying this patch when build NIOS2:
> Hmm, that is strange.
>
> Did you apply the entire series or atleast upto the nios2 patch ? Generic
> vm_get_page_prot() should not be called (which is build complaining here)
> when ARCH_HAS_VM_GET_PAGE_PROT is already enabled on nios2 platform.
>
> Ran a quick build test on nios2 for the entire series and also just upto
> this particular patch, build was successful.
>
Please refer to the latest version V2 instead.
https://lore.kernel.org/linux-mm/1645425519-9034-1-git-send-email-anshuman.khandual@xxxxxxx/
