There are some minor issues with support 64-bit PTEs on a 32-bit processor
when dealing with SMP.
* We need to order the stores in set_pte_at to make sure the flag word
is set second.
* We want to ensure that set_pte_at is always called w/a pte that is not
valid. Change kunmap_atomic to always clear the pte.
* Change pte_clear to use pte_update so only the flag word is cleared
Signed-off-by: Kumar Gala <[EMAIL PROTECTED]>
---
Do we want to unconditionally change kunmap_atomic or not?
- k
include/asm-powerpc/highmem.h | 4 ++--
include/asm-powerpc/pgtable-ppc32.h | 14 ++++++++++----
2 files changed, 12 insertions(+), 6 deletions(-)
diff --git a/include/asm-powerpc/highmem.h b/include/asm-powerpc/highmem.h
index 5d99b64..7f101d1 100644
--- a/include/asm-powerpc/highmem.h
+++ b/include/asm-powerpc/highmem.h
@@ -97,7 +97,6 @@ static inline void *kmap_atomic(struct page *page, enum
km_type type)
static inline void kunmap_atomic(void *kvaddr, enum km_type type)
{
-#ifdef CONFIG_DEBUG_HIGHMEM
unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
enum fixed_addresses idx = type + KM_TYPE_NR*smp_processor_id();
@@ -106,7 +105,9 @@ static inline void kunmap_atomic(void *kvaddr, enum km_type
type)
return;
}
+#ifdef CONFIG_DEBUG_HIGHMEM
BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
+#endif
/*
* force other mappings to Oops if they'll try to access
@@ -114,7 +115,6 @@ static inline void kunmap_atomic(void *kvaddr, enum km_type
type)
*/
pte_clear(&init_mm, vaddr, kmap_pte-idx);
flush_tlb_page(NULL, vaddr);
-#endif
pagefault_enable();
}
diff --git a/include/asm-powerpc/pgtable-ppc32.h
b/include/asm-powerpc/pgtable-ppc32.h
index 3a96d00..2436eab 100644
--- a/include/asm-powerpc/pgtable-ppc32.h
+++ b/include/asm-powerpc/pgtable-ppc32.h
@@ -502,7 +502,7 @@ extern unsigned long bad_call_to_PMD_PAGE_SIZE(void);
#define pte_none(pte) ((pte_val(pte) & ~_PTE_NONE_MASK) == 0)
#define pte_present(pte) (pte_val(pte) & _PAGE_PRESENT)
-#define pte_clear(mm,addr,ptep) do { set_pte_at((mm), (addr), (ptep),
__pte(0)); } while (0)
+#define pte_clear(mm,addr,ptep) do { pte_update(ptep, ~0, 0); } while
(0)
#define pmd_none(pmd) (!pmd_val(pmd))
#define pmd_bad(pmd) (pmd_val(pmd) & _PMD_BAD)
@@ -593,9 +593,6 @@ static inline unsigned long pte_update(pte_t *p,
return old;
}
#else /* CONFIG_PTE_64BIT */
-/* TODO: Change that to only modify the low word and move set_pte_at()
- * out of line
- */
static inline unsigned long long pte_update(pte_t *p,
unsigned long clr,
unsigned long set)
@@ -639,8 +636,17 @@ static inline void set_pte_at(struct mm_struct *mm,
unsigned long addr,
#if _PAGE_HASHPTE != 0
pte_update(ptep, ~_PAGE_HASHPTE, pte_val(pte) & ~_PAGE_HASHPTE);
#else
+#if defined(CONFIG_PTE_64BIT) && defined(CONFIG_SMP)
+ __asm__ __volatile__("\
+ stw%U0%X0 %2,%0\n\
+ eieio\n\
+ stw%U0%X0 %L2,%1"
+ : "=m" (*ptep), "=m" (*((unsigned char *)ptep+4))
+ : "r" (pte) : "memory");
+#else
*ptep = pte;
#endif
+#endif
}
/*
--
1.5.5.1
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