#endif
#ifdef CONFIG_ARM_LPAE
-static void cpu_set_reserved_ttbr0(void)
-{
- /*
- * Set TTBR0 to swapper_pg_dir which contains only global entries. The
- * ASID is set to 0.
- */
- cpu_set_ttbr(0, __pa(swapper_pg_dir));
- isb();
-}
+/*
+ * With LPAE, the ASID and page tables are updated atomicly, so there is
+ * no need for a reserved set of tables (the active ASID tracking prevents
+ * any issues across a rollover).
+ */
+#define cpu_set_reserved_ttbr0()
#else
static void cpu_set_reserved_ttbr0(void)
{
u32 ttb;
- /* Copy TTBR1 into TTBR0 */
+ /*
+ * Copy TTBR1 into TTBR0.
+ * This points at swapper_pg_dir, which contains only global
+ * entries so any speculative walks are perfectly safe.
+ */
asm volatile(
" mrc p15, 0, %0, c2, c0, 1 @ read TTBR1\n"
" mcr p15, 0, %0, c2, c0, 0 @ set TTBR0\n"
static u64 new_context(struct mm_struct *mm, unsigned int cpu)
{
+ static u32 cur_idx = 1;
u64 asid = atomic64_read(&mm->context.id);
u64 generation = atomic64_read(&asid_generation);
* as we reserve ASID #0 to switch via TTBR0 and indicate
* rollover events.
*/
- asid = find_next_zero_bit(asid_map, NUM_USER_ASIDS, 1);
+ asid = find_next_zero_bit(asid_map, NUM_USER_ASIDS, cur_idx);
if (asid == NUM_USER_ASIDS) {
generation = atomic64_add_return(ASID_FIRST_VERSION,
&asid_generation);
asid = find_next_zero_bit(asid_map, NUM_USER_ASIDS, 1);
}
__set_bit(asid, asid_map);
+ cur_idx = asid;
asid |= generation;
cpumask_clear(mm_cpumask(mm));
}