lkml.org 
[lkml]   [2022]   [Feb]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [RFC V1 04/31] powerpc/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT
From
Date


On 2/3/22 11:45 PM, Mike Rapoport wrote:
> On Mon, Jan 24, 2022 at 06:26:41PM +0530, 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. While here, this also
>> localizes arch_vm_get_page_prot() as powerpc_vm_get_page_prot().
>>
>> Cc: Michael Ellerman <mpe@ellerman.id.au>
>> Cc: Paul Mackerras <paulus@samba.org>
>> Cc: linuxppc-dev@lists.ozlabs.org
>> Cc: linux-kernel@vger.kernel.org
>> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
>> ---
>> arch/powerpc/Kconfig | 1 +
>> arch/powerpc/include/asm/mman.h | 3 +-
>> arch/powerpc/include/asm/pgtable.h | 19 ------------
>> arch/powerpc/mm/mmap.c | 47 ++++++++++++++++++++++++++++++
>> 4 files changed, 49 insertions(+), 21 deletions(-)
>>
>> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
>> index b779603978e1..ddb4a3687c05 100644
>> --- a/arch/powerpc/Kconfig
>> +++ b/arch/powerpc/Kconfig
>> @@ -135,6 +135,7 @@ config PPC
>> select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
>> select ARCH_HAS_UACCESS_FLUSHCACHE
>> select ARCH_HAS_UBSAN_SANITIZE_ALL
>> + select ARCH_HAS_VM_GET_PAGE_PROT
>> select ARCH_HAVE_NMI_SAFE_CMPXCHG
>> select ARCH_KEEP_MEMBLOCK
>> select ARCH_MIGHT_HAVE_PC_PARPORT
>> diff --git a/arch/powerpc/include/asm/mman.h b/arch/powerpc/include/asm/mman.h
>> index 7cb6d18f5cd6..7b10c2031e82 100644
>> --- a/arch/powerpc/include/asm/mman.h
>> +++ b/arch/powerpc/include/asm/mman.h
>> @@ -24,7 +24,7 @@ static inline unsigned long arch_calc_vm_prot_bits(unsigned long prot,
>> }
>> #define arch_calc_vm_prot_bits(prot, pkey) arch_calc_vm_prot_bits(prot, pkey)
>>
>> -static inline pgprot_t arch_vm_get_page_prot(unsigned long vm_flags)
>> +static inline pgprot_t powerpc_vm_get_page_prot(unsigned long vm_flags)
>> {
>> #ifdef CONFIG_PPC_MEM_KEYS
>> return (vm_flags & VM_SAO) ?
>> @@ -34,7 +34,6 @@ static inline pgprot_t arch_vm_get_page_prot(unsigned long vm_flags)
>> return (vm_flags & VM_SAO) ? __pgprot(_PAGE_SAO) : __pgprot(0);
>> #endif
>> }
>> -#define arch_vm_get_page_prot(vm_flags) arch_vm_get_page_prot(vm_flags)
>>
>> static inline bool arch_validate_prot(unsigned long prot, unsigned long addr)
>> {
>> diff --git a/arch/powerpc/include/asm/pgtable.h b/arch/powerpc/include/asm/pgtable.h
>> index d564d0ecd4cd..3cbb6de20f9d 100644
>> --- a/arch/powerpc/include/asm/pgtable.h
>> +++ b/arch/powerpc/include/asm/pgtable.h
>> @@ -20,25 +20,6 @@ struct mm_struct;
>> #include <asm/nohash/pgtable.h>
>> #endif /* !CONFIG_PPC_BOOK3S */
>>
>> -/* Note due to the way vm flags are laid out, the bits are XWR */
>> -#define __P000 PAGE_NONE
>> -#define __P001 PAGE_READONLY
>> -#define __P010 PAGE_COPY
>> -#define __P011 PAGE_COPY
>> -#define __P100 PAGE_READONLY_X
>> -#define __P101 PAGE_READONLY_X
>> -#define __P110 PAGE_COPY_X
>> -#define __P111 PAGE_COPY_X
>> -
>> -#define __S000 PAGE_NONE
>> -#define __S001 PAGE_READONLY
>> -#define __S010 PAGE_SHARED
>> -#define __S011 PAGE_SHARED
>> -#define __S100 PAGE_READONLY_X
>> -#define __S101 PAGE_READONLY_X
>> -#define __S110 PAGE_SHARED_X
>> -#define __S111 PAGE_SHARED_X
>> -
>> #ifndef __ASSEMBLY__
>>
>> #ifndef MAX_PTRS_PER_PGD
>> diff --git a/arch/powerpc/mm/mmap.c b/arch/powerpc/mm/mmap.c
>> index c475cf810aa8..7f05e7903bd2 100644
>> --- a/arch/powerpc/mm/mmap.c
>> +++ b/arch/powerpc/mm/mmap.c
>> @@ -254,3 +254,50 @@ void arch_pick_mmap_layout(struct mm_struct *mm, struct rlimit *rlim_stack)
>> mm->get_unmapped_area = arch_get_unmapped_area_topdown;
>> }
>> }
>> +
>> +static inline 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 PAGE_NONE;
>> + case VM_READ:
>> + return PAGE_READONLY;
>> + case VM_WRITE:
>> + return PAGE_COPY;
>> + case VM_READ | VM_WRITE:
>> + return PAGE_COPY;
>> + case VM_EXEC:
>> + return PAGE_READONLY_X;
>> + case VM_EXEC | VM_READ:
>> + return PAGE_READONLY_X;
>> + case VM_EXEC | VM_WRITE:
>> + return PAGE_COPY_X;
>> + case VM_EXEC | VM_READ | VM_WRITE:
>> + return PAGE_COPY_X;
>> + case VM_SHARED:
>> + return PAGE_NONE;
>> + case VM_SHARED | VM_READ:
>> + return PAGE_READONLY;
>> + case VM_SHARED | VM_WRITE:
>> + return PAGE_SHARED;
>> + case VM_SHARED | VM_READ | VM_WRITE:
>> + return PAGE_SHARED;
>> + case VM_SHARED | VM_EXEC:
>> + return PAGE_READONLY_X;
>> + case VM_SHARED | VM_EXEC | VM_READ:
>> + return PAGE_READONLY_X;
>> + case VM_SHARED | VM_EXEC | VM_WRITE:
>> + return PAGE_SHARED_X;
>> + case VM_SHARED | VM_EXEC | VM_READ | VM_WRITE:
>> + return PAGE_SHARED_X;
>> + default:
>> + BUILD_BUG();
>> + }
>> +}
>> +
>> +pgprot_t vm_get_page_prot(unsigned long vm_flags)
>> +{
>> + return __pgprot(pgprot_val(__vm_get_page_prot(vm_flags)) |
>> + pgprot_val(powerpc_vm_get_page_prot(vm_flags)));
> Any reason to keep powerpc_vm_get_page_prot() rather than open code it
> here?
>
> This applies to other architectures that implement arch_vm_get_page_prot()
> and/or arch_filter_pgprot() as well.

Just to minimize the code churn ! But I will be happy to open code them
here (and in other platforms) if that will be preferred.

\
 
 \ /
  Last update: 2022-02-04 03:59    [W:0.176 / U:0.136 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site