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Diffstat (limited to 'arch/powerpc/include/asm/kvm_book3s_64.h')
-rw-r--r--arch/powerpc/include/asm/kvm_book3s_64.h58
1 files changed, 34 insertions, 24 deletions
diff --git a/arch/powerpc/include/asm/kvm_book3s_64.h b/arch/powerpc/include/asm/kvm_book3s_64.h
index 154ba3f6b7a9..86d638a3b359 100644
--- a/arch/powerpc/include/asm/kvm_book3s_64.h
+++ b/arch/powerpc/include/asm/kvm_book3s_64.h
@@ -159,36 +159,46 @@ static inline int hpte_cache_flags_ok(unsigned long ptel, unsigned long io_type)
}
/*
- * Lock and read a linux PTE. If it's present and writable, atomically
- * set dirty and referenced bits and return the PTE, otherwise return 0.
+ * If it's present and writable, atomically set dirty and referenced bits and
+ * return the PTE, otherwise return 0. If we find a transparent hugepage
+ * and if it is marked splitting we return 0;
*/
-static inline pte_t kvmppc_read_update_linux_pte(pte_t *p, int writing)
+static inline pte_t kvmppc_read_update_linux_pte(pte_t *ptep, int writing,
+ unsigned int hugepage)
{
- pte_t pte, tmp;
-
- /* wait until _PAGE_BUSY is clear then set it atomically */
- __asm__ __volatile__ (
- "1: ldarx %0,0,%3\n"
- " andi. %1,%0,%4\n"
- " bne- 1b\n"
- " ori %1,%0,%4\n"
- " stdcx. %1,0,%3\n"
- " bne- 1b"
- : "=&r" (pte), "=&r" (tmp), "=m" (*p)
- : "r" (p), "i" (_PAGE_BUSY)
- : "cc");
-
- if (pte_present(pte)) {
- pte = pte_mkyoung(pte);
- if (writing && pte_write(pte))
- pte = pte_mkdirty(pte);
- }
+ pte_t old_pte, new_pte = __pte(0);
+
+ while (1) {
+ old_pte = pte_val(*ptep);
+ /*
+ * wait until _PAGE_BUSY is clear then set it atomically
+ */
+ if (unlikely(old_pte & _PAGE_BUSY)) {
+ cpu_relax();
+ continue;
+ }
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+ /* If hugepage and is trans splitting return None */
+ if (unlikely(hugepage &&
+ pmd_trans_splitting(pte_pmd(old_pte))))
+ return __pte(0);
+#endif
+ /* If pte is not present return None */
+ if (unlikely(!(old_pte & _PAGE_PRESENT)))
+ return __pte(0);
- *p = pte; /* clears _PAGE_BUSY */
+ new_pte = pte_mkyoung(old_pte);
+ if (writing && pte_write(old_pte))
+ new_pte = pte_mkdirty(new_pte);
- return pte;
+ if (old_pte == __cmpxchg_u64((unsigned long *)ptep, old_pte,
+ new_pte))
+ break;
+ }
+ return new_pte;
}
+
/* Return HPTE cache control bits corresponding to Linux pte bits */
static inline unsigned long hpte_cache_bits(unsigned long pte_val)
{