[PATCH v2 17/45] powerpc/mm: PTE_ATOMIC_UPDATES is only for 40x

From: Christophe Leroy
Date: Wed May 06 2020 - 12:48:43 EST


Only 40x still uses PTE_ATOMIC_UPDATES.
40x cannot not select CONFIG_PTE64_BIT.

Drop handling of PTE_ATOMIC_UPDATES:
- In nohash/64
- In nohash/32 for CONFIG_PTE_64BIT

Keep PTE_ATOMIC_UPDATES only for nohash/32 for !CONFIG_PTE_64BIT

Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
---
arch/powerpc/include/asm/nohash/32/pgtable.h | 17 ------------
arch/powerpc/include/asm/nohash/64/pgtable.h | 28 +-------------------
2 files changed, 1 insertion(+), 44 deletions(-)

diff --git a/arch/powerpc/include/asm/nohash/32/pgtable.h b/arch/powerpc/include/asm/nohash/32/pgtable.h
index b04ba257fddb..523c4c3876c5 100644
--- a/arch/powerpc/include/asm/nohash/32/pgtable.h
+++ b/arch/powerpc/include/asm/nohash/32/pgtable.h
@@ -262,25 +262,8 @@ static inline unsigned long long pte_update(pte_t *p,
unsigned long clr,
unsigned long set)
{
-#ifdef PTE_ATOMIC_UPDATES
- unsigned long long old;
- unsigned long tmp;
-
- __asm__ __volatile__("\
-1: lwarx %L0,0,%4\n\
- lwzx %0,0,%3\n\
- andc %1,%L0,%5\n\
- or %1,%1,%6\n"
- PPC405_ERR77(0,%3)
-" stwcx. %1,0,%4\n\
- bne- 1b"
- : "=&r" (old), "=&r" (tmp), "=m" (*p)
- : "r" (p), "r" ((unsigned long)(p) + 4), "r" (clr), "r" (set), "m" (*p)
- : "cc" );
-#else /* PTE_ATOMIC_UPDATES */
unsigned long long old = pte_val(*p);
*p = __pte((old & ~(unsigned long long)clr) | set);
-#endif /* !PTE_ATOMIC_UPDATES */

#ifdef CONFIG_44x
if ((old & _PAGE_USER) && (old & _PAGE_EXEC))
diff --git a/arch/powerpc/include/asm/nohash/64/pgtable.h b/arch/powerpc/include/asm/nohash/64/pgtable.h
index 9a33b8bd842d..9c703b140d64 100644
--- a/arch/powerpc/include/asm/nohash/64/pgtable.h
+++ b/arch/powerpc/include/asm/nohash/64/pgtable.h
@@ -211,22 +211,9 @@ static inline unsigned long pte_update(struct mm_struct *mm,
unsigned long set,
int huge)
{
-#ifdef PTE_ATOMIC_UPDATES
- unsigned long old, tmp;
-
- __asm__ __volatile__(
- "1: ldarx %0,0,%3 # pte_update\n\
- andc %1,%0,%4 \n\
- or %1,%1,%6\n\
- stdcx. %1,0,%3 \n\
- bne- 1b"
- : "=&r" (old), "=&r" (tmp), "=m" (*ptep)
- : "r" (ptep), "r" (clr), "m" (*ptep), "r" (set)
- : "cc" );
-#else
unsigned long old = pte_val(*ptep);
*ptep = __pte((old & ~clr) | set);
-#endif
+
/* huge pages use the old page table lock */
if (!huge)
assert_pte_locked(mm, addr);
@@ -310,21 +297,8 @@ static inline void __ptep_set_access_flags(struct vm_area_struct *vma,
unsigned long bits = pte_val(entry) &
(_PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_RW | _PAGE_EXEC);

-#ifdef PTE_ATOMIC_UPDATES
- unsigned long old, tmp;
-
- __asm__ __volatile__(
- "1: ldarx %0,0,%4\n\
- or %0,%3,%0\n\
- stdcx. %0,0,%4\n\
- bne- 1b"
- :"=&r" (old), "=&r" (tmp), "=m" (*ptep)
- :"r" (bits), "r" (ptep), "m" (*ptep)
- :"cc");
-#else
unsigned long old = pte_val(*ptep);
*ptep = __pte(old | bits);
-#endif

flush_tlb_page(vma, address);
}
--
2.25.0