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-rw-r--r--arch/powerpc/mm/hugetlbpage-hash64.c40
1 files changed, 22 insertions, 18 deletions
diff --git a/arch/powerpc/mm/hugetlbpage-hash64.c b/arch/powerpc/mm/hugetlbpage-hash64.c
index 1995398..cc5c273 100644
--- a/arch/powerpc/mm/hugetlbpage-hash64.c
+++ b/arch/powerpc/mm/hugetlbpage-hash64.c
@@ -21,21 +21,13 @@ int __hash_page_huge(unsigned long ea, unsigned long access, unsigned long vsid,
unsigned long old_pte, new_pte;
unsigned long va, rflags, pa, sz;
long slot;
- int err = 1;
BUG_ON(shift != mmu_psize_defs[mmu_psize].shift);
/* Search the Linux page table for a match with va */
va = hpt_va(ea, vsid, ssize);
- /*
- * Check the user's access rights to the page. If access should be
- * prevented then send the problem up to do_page_fault.
- */
- if (unlikely(access & ~pte_val(*ptep)))
- goto out;
- /*
- * At this point, we have a pte (old_pte) which can be used to build
+ /* At this point, we have a pte (old_pte) which can be used to build
* or update an HPTE. There are 2 cases:
*
* 1. There is a valid (present) pte with no associated HPTE (this is
@@ -49,9 +41,17 @@ int __hash_page_huge(unsigned long ea, unsigned long access, unsigned long vsid,
do {
old_pte = pte_val(*ptep);
- if (old_pte & _PAGE_BUSY)
- goto out;
+ /* If PTE busy, retry the access */
+ if (unlikely(old_pte & _PAGE_BUSY))
+ return 0;
+ /* If PTE permissions don't match, take page fault */
+ if (unlikely(access & ~old_pte))
+ return 1;
+ /* Try to lock the PTE, add ACCESSED and DIRTY if it was
+ * a write access */
new_pte = old_pte | _PAGE_BUSY | _PAGE_ACCESSED;
+ if (access & _PAGE_RW)
+ new_pte |= _PAGE_DIRTY;
} while(old_pte != __cmpxchg_u64((unsigned long *)ptep,
old_pte, new_pte));
@@ -121,8 +121,16 @@ repeat:
}
}
- if (unlikely(slot == -2))
- panic("hash_huge_page: pte_insert failed\n");
+ /*
+ * Hypervisor failure. Restore old pte and return -1
+ * similar to __hash_page_*
+ */
+ if (unlikely(slot == -2)) {
+ *ptep = __pte(old_pte);
+ hash_failure_debug(ea, access, vsid, trap, ssize,
+ mmu_psize, old_pte);
+ return -1;
+ }
new_pte |= (slot << 12) & (_PAGE_F_SECOND | _PAGE_F_GIX);
}
@@ -131,9 +139,5 @@ repeat:
* No need to use ldarx/stdcx here
*/
*ptep = __pte(new_pte & ~_PAGE_BUSY);
-
- err = 0;
-
- out:
- return err;
+ return 0;
}
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