We need to search linux "pte" to get "pte" attributes for
setting TLB in KVM.
This patch defines a linux_pte_lookup() function for same.
Signed-off-by: Bharat Bhushan <bharat.bhushan@xxxxxxxxxxxxx>
---
arch/powerpc/include/asm/pgtable.h | 35 +++++++++++++++++++++++++++++++++++
1 files changed, 35 insertions(+), 0 deletions(-)
diff --git a/arch/powerpc/include/asm/pgtable.h b/arch/powerpc/include/asm/pgtable.h
index 7d6eacf..fd26c04 100644
--- a/arch/powerpc/include/asm/pgtable.h
+++ b/arch/powerpc/include/asm/pgtable.h
@@ -223,6 +223,41 @@ extern int gup_hugepte(pte_t *ptep, unsigned long sz, unsigned long addr,
#endif
pte_t *find_linux_pte_or_hugepte(pgd_t *pgdir, unsigned long ea,
unsigned *shift);
+
+static inline pte_t lookup_linux_pte(pgd_t *pgdir, unsigned long hva,
+ unsigned long *pte_sizep)
+{
+ pte_t *ptep;
+ pte_t pte;
+ unsigned long ps = *pte_sizep;
+ unsigned int shift;
+
+ ptep = find_linux_pte_or_hugepte(pgdir, hva, &shift);
+ if (!ptep)
+ return __pte(0);
+ if (shift)
+ *pte_sizep = 1ul << shift;
+ else
+ *pte_sizep = PAGE_SIZE;
+
+ if (ps > *pte_sizep)
+ return __pte(0);
+
+ /* wait until _PAGE_BUSY is clear */
+ while (1) {
+ pte = pte_val(*ptep);
+ if (unlikely(pte & _PAGE_BUSY)) {
+ cpu_relax();
+ continue;
+ }
+ }
+
+ /* If pte is not present return None */
+ if (unlikely(!(pte & _PAGE_PRESENT)))
+ return __pte(0);
+
+ return pte;
+}
#endif /* __ASSEMBLY__ */
#endif /* __KERNEL__ */
--
1.7.0.4
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
