@@ -49,6 +49,20 @@ static inline int hash__hugepd_ok(hugepd_t hpd)
}
#endif
+/*
+ * 4K PTE format is different from 64K PTE format. Saving the hash_slot is just
+ * a matter of returning the PTE bits that need to be modified. On 64K PTE,
+ * things are a little more involved and hence needs many more parameters to
+ * accomplish the same. However we want to abstract this out from the caller by
+ * keeping the prototype consistent across the two formats.
+ */
+static inline unsigned long pte_set_hidx(pte_t *ptep, real_pte_t rpte,
+ unsigned int subpg_index, unsigned long hidx)
+{
+ return (hidx << H_PAGE_F_GIX_SHIFT) &
+ (H_PAGE_F_SECOND | H_PAGE_F_GIX);
+}
+
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
static inline char *get_hpte_slot_array(pmd_t *pmdp)
@@ -68,6 +68,8 @@ static inline real_pte_t __real_pte(pte_t pte, pte_t *ptep)
return rpte;
}
+#define HIDX_BITS(x, index) (x << (index << 2))
+
static inline unsigned long __rpte_to_hidx(real_pte_t rpte, unsigned long index)
{
if ((pte_val(rpte.pte) & H_PAGE_COMBO))
@@ -75,6 +77,29 @@ static inline unsigned long __rpte_to_hidx(real_pte_t rpte, unsigned long index)
return (pte_val(rpte.pte) >> H_PAGE_F_GIX_SHIFT) & 0xf;
}
+/*
+ * Commit the hidx and return PTE bits that needs to be modified. The caller is
+ * expected to modify the PTE bits accordingly and commit the PTE to memory.
+ */
+static inline unsigned long pte_set_hidx(pte_t *ptep, real_pte_t rpte,
+ unsigned int subpg_index, unsigned long hidx)
+{
+ unsigned long *hidxp = (unsigned long *)(ptep + PTRS_PER_PTE);
+
+ rpte.hidx &= ~HIDX_BITS(0xfUL, subpg_index);
+ *hidxp = rpte.hidx | HIDX_BITS(hidx, subpg_index);
+
+ /*
+ * Anyone reading PTE must ensure hidx bits are read after reading the
+ * PTE by using the read-side barrier smp_rmb(). __real_pte() can be
+ * used for that.
+ */
+ smp_wmb();
+
+ /* No PTE bits to be modified, return 0x0UL */
+ return 0x0UL;
+}
+
#define __rpte_to_pte(r) ((r).pte)
extern bool __rpte_sub_valid(real_pte_t rpte, unsigned long index);
/*