bybrooklyn/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-04-18 06:44:00 -04:00
Code Issues Packages Projects Releases Wiki Activity

powerpc/nohash/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE

Browse Source 
Let's support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on 32bit and 64bit.

On 64bit, let's use MSB 56 (LSB 7), located right next to the page type. 
On 32bit, let's use LSB 2 to avoid stealing one bit from the swap offset.

There seems to be no real reason why these bits cannot be used for swap
PTEs.  The important part is that _PAGE_PRESENT and _PAGE_HASHPTE remain
0.

While at it, mask the type in __swp_entry() and remove _PAGE_BIT_SWAP_TYPE
from pte-e500.h: while it was used in 64bit code it was ignored in 32bit
code.

Link: https://lkml.kernel.org/r/20230113171026.582290-19-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
David Hildenbrand
2023-01-13 18:10:18 +01:00
committed by Andrew Morton
parent 8897ebff37
commit 2bba2ffbe0
7 changed files with 63 additions and 28 deletions
Download Patch File Download Diff File Expand all files Collapse all files

16
arch/powerpc/include/asm/nohash/pgtable.h
View File

@@ -151,6 +151,22 @@ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
return __pte((pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot));
}
#define __HAVE_ARCH_PTE_SWP_EXCLUSIVE
static inline int pte_swp_exclusive(pte_t pte)
{
return pte_val(pte) & _PAGE_SWP_EXCLUSIVE;
}
static inline pte_t pte_swp_mkexclusive(pte_t pte)
{
return __pte(pte_val(pte) | _PAGE_SWP_EXCLUSIVE);
}
static inline pte_t pte_swp_clear_exclusive(pte_t pte)
{
return __pte(pte_val(pte) & ~_PAGE_SWP_EXCLUSIVE);
}
/* Insert a PTE, top-level function is out of line. It uses an inline
* low level function in the respective pgtable-* files
*/