diff options
| author | Kumar Gala <galak@freescale.com> | 2005-04-16 15:24:20 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:24:20 -0700 |
| commit | 7a1e335085ead05da08f791340f58b493126894d (patch) | |
| tree | 5b1a763061d68caef26ec85d55404d868bab7a74 | |
| parent | 0c541b4406a68e74d94ddb667c69d9e03bce8681 (diff) | |
[PATCH] ppc32: Fix pte_update for 64-bit PTEs
While the existing pte_update code handled atomically modifying a 64-bit PTE,
it did not return all 64-bits of the PTE before it was modified. This causes
problems in some places that expect the full PTE to be returned, like
ptep_get_and_clear().
Created a new pte_update function that is conditional on CONFIG_PTE_64BIT. It
atomically reads the low PTE word which all PTE flags are required to be in
and returns a premodified full 64-bit PTE.
Since we now have an explicit 64-bit PTE version of pte_update we can also
remove the hack that existed to get the low PTE word regardless of size.
Signed-off-by: Kumar Gala <kumar.gala@freescale.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
| -rw-r--r-- | include/asm-ppc/pgtable.h | 29 |
1 files changed, 25 insertions, 4 deletions
diff --git a/include/asm-ppc/pgtable.h b/include/asm-ppc/pgtable.h index 19dfb7abaa21..2e88cd9feffe 100644 --- a/include/asm-ppc/pgtable.h +++ b/include/asm-ppc/pgtable.h @@ -526,10 +526,10 @@ extern void add_hash_page(unsigned context, unsigned long va, * Atomic PTE updates. * * pte_update clears and sets bit atomically, and returns - * the old pte value. - * The ((unsigned long)(p+1) - 4) hack is to get to the least-significant - * 32 bits of the PTE regardless of whether PTEs are 32 or 64 bits. + * the old pte value. In the 64-bit PTE case we lock around the + * low PTE word since we expect ALL flag bits to be there */ +#ifndef CONFIG_PTE_64BIT static inline unsigned long pte_update(pte_t *p, unsigned long clr, unsigned long set) { @@ -543,10 +543,31 @@ static inline unsigned long pte_update(pte_t *p, unsigned long clr, " stwcx. %1,0,%3\n\ bne- 1b" : "=&r" (old), "=&r" (tmp), "=m" (*p) - : "r" ((unsigned long)(p+1) - 4), "r" (clr), "r" (set), "m" (*p) + : "r" (p), "r" (clr), "r" (set), "m" (*p) : "cc" ); return old; } +#else +static inline unsigned long long pte_update(pte_t *p, unsigned long clr, + unsigned long set) +{ + 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" ); + return old; +} +#endif /* * set_pte stores a linux PTE into the linux page table. |