#include <asm/cacheflush.h>
#include <asm/cachetype.h>
#include <asm/proc-fns.h>
+#include <asm-generic/mm_hooks.h>
void __check_kvm_seq(struct mm_struct *mm);
void __init_new_context(struct task_struct *tsk, struct mm_struct *mm);
void __new_context(struct mm_struct *mm);
+void cpu_set_reserved_ttbr0(void);
-static inline void check_context(struct mm_struct *mm)
+static inline void switch_new_context(struct mm_struct *mm)
{
- /*
- * This code is executed with interrupts enabled. Therefore,
- * mm->context.id cannot be updated to the latest ASID version
- * on a different CPU (and condition below not triggered)
- * without first getting an IPI to reset the context. The
- * alternative is to take a read_lock on mm->context.id_lock
- * (after changing its type to rwlock_t).
- */
- if (unlikely((mm->context.id ^ cpu_last_asid) >> ASID_BITS))
- __new_context(mm);
+ unsigned long flags;
+
+ __new_context(mm);
+
+ local_irq_save(flags);
+ cpu_switch_mm(mm->pgd, mm);
+ local_irq_restore(flags);
+}
+static inline void check_and_switch_context(struct mm_struct *mm,
+ struct task_struct *tsk)
+{
if (unlikely(mm->context.kvm_seq != init_mm.context.kvm_seq))
__check_kvm_seq(mm);
+
+ /*
+ * Required during context switch to avoid speculative page table
+ * walking with the wrong TTBR.
+ */
+ cpu_set_reserved_ttbr0();
+
+ if (!((mm->context.id ^ cpu_last_asid) >> ASID_BITS))
+ /*
+ * The ASID is from the current generation, just switch to the
+ * new pgd. This condition is only true for calls from
+ * context_switch() and interrupts are already disabled.
+ */
+ cpu_switch_mm(mm->pgd, mm);
+ else if (irqs_disabled())
+ /*
+ * Defer the new ASID allocation until after the context
+ * switch critical region since __new_context() cannot be
+ * called with interrupts disabled (it sends IPIs).
+ */
+ set_ti_thread_flag(task_thread_info(tsk), TIF_SWITCH_MM);
+ else
+ /*
+ * That is a direct call to switch_mm() or activate_mm() with
+ * interrupts enabled and a new context.
+ */
+ switch_new_context(mm);
}
#define init_new_context(tsk,mm) (__init_new_context(tsk,mm),0)
-#else
+#define finish_arch_post_lock_switch \
+ finish_arch_post_lock_switch
+static inline void finish_arch_post_lock_switch(void)
+{
+ if (test_and_clear_thread_flag(TIF_SWITCH_MM))
+ switch_new_context(current->mm);
+}
+
+#else /* !CONFIG_CPU_HAS_ASID */
-static inline void check_context(struct mm_struct *mm)
+static inline void check_and_switch_context(struct mm_struct *mm,
+ struct task_struct *tsk)
{
#ifdef CONFIG_MMU
if (unlikely(mm->context.kvm_seq != init_mm.context.kvm_seq))
__check_kvm_seq(mm);
+ cpu_switch_mm(mm->pgd, mm);
#endif
}
#define init_new_context(tsk,mm) 0
-#endif
+#define finish_arch_post_lock_switch() do { } while (0)
+
+#endif /* CONFIG_CPU_HAS_ASID */
#define destroy_context(mm) do { } while(0)
struct mm_struct **crt_mm = &per_cpu(current_mm, cpu);
*crt_mm = next;
#endif
- check_context(next);
- cpu_switch_mm(next->pgd, next);
+ check_and_switch_context(next, tsk);
if (cache_is_vivt())
cpumask_clear_cpu(cpu, mm_cpumask(prev));
}
#define deactivate_mm(tsk,mm) do { } while (0)
#define activate_mm(prev,next) switch_mm(prev, next, NULL)
-/*
- * We are inserting a "fake" vma for the user-accessible vector page so
- * gdb and friends can get to it through ptrace and /proc/<pid>/mem.
- * But we also want to remove it before the generic code gets to see it
- * during process exit or the unmapping of it would cause total havoc.
- * (the macro is used as remove_vma() is static to mm/mmap.c)
- */
-#define arch_exit_mmap(mm) \
-do { \
- struct vm_area_struct *high_vma = find_vma(mm, 0xffff0000); \
- if (high_vma) { \
- BUG_ON(high_vma->vm_next); /* it should be last */ \
- if (high_vma->vm_prev) \
- high_vma->vm_prev->vm_next = NULL; \
- else \
- mm->mmap = NULL; \
- rb_erase(&high_vma->vm_rb, &mm->mm_rb); \
- mm->mmap_cache = NULL; \
- mm->map_count--; \
- remove_vma(high_vma); \
- } \
-} while (0)
-
-static inline void arch_dup_mmap(struct mm_struct *oldmm,
- struct mm_struct *mm)
-{
-}
-
#endif