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authorMax Krummenacher <max.krummenacher@toradex.com>2018-03-13 11:32:58 +0100
committerMax Krummenacher <max.krummenacher@toradex.com>2018-03-13 11:32:58 +0100
commit6fb9f3c8a4992f67dcb3ce413df2e22e96b2d400 (patch)
tree6e3071b2f179a62b027669ac2a238383293bf941 /arch/x86/include/asm/mmu_context.h
parenta126a5e5dc2fcc5cb36af14c89b440cc8e3bab30 (diff)
parent8b5ab55d254f36e89b1b53aeac7223d2d102483e (diff)
Merge tag 'v4.4.121' into toradex_vf_4.4-nextColibri-VF_LXDE-Image_2.8b2.97-20180331
This is the 4.4.121 stable release
Diffstat (limited to 'arch/x86/include/asm/mmu_context.h')
-rw-r--r--arch/x86/include/asm/mmu_context.h103
1 files changed, 5 insertions, 98 deletions
diff --git a/arch/x86/include/asm/mmu_context.h b/arch/x86/include/asm/mmu_context.h
index bfd9b2a35a0b..9bfc5fd77015 100644
--- a/arch/x86/include/asm/mmu_context.h
+++ b/arch/x86/include/asm/mmu_context.h
@@ -98,109 +98,16 @@ static inline void load_mm_ldt(struct mm_struct *mm)
static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
{
-#ifdef CONFIG_SMP
if (this_cpu_read(cpu_tlbstate.state) == TLBSTATE_OK)
this_cpu_write(cpu_tlbstate.state, TLBSTATE_LAZY);
-#endif
}
-static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
- struct task_struct *tsk)
-{
- unsigned cpu = smp_processor_id();
-
- if (likely(prev != next)) {
-#ifdef CONFIG_SMP
- this_cpu_write(cpu_tlbstate.state, TLBSTATE_OK);
- this_cpu_write(cpu_tlbstate.active_mm, next);
-#endif
- cpumask_set_cpu(cpu, mm_cpumask(next));
-
- /*
- * Re-load page tables.
- *
- * This logic has an ordering constraint:
- *
- * CPU 0: Write to a PTE for 'next'
- * CPU 0: load bit 1 in mm_cpumask. if nonzero, send IPI.
- * CPU 1: set bit 1 in next's mm_cpumask
- * CPU 1: load from the PTE that CPU 0 writes (implicit)
- *
- * We need to prevent an outcome in which CPU 1 observes
- * the new PTE value and CPU 0 observes bit 1 clear in
- * mm_cpumask. (If that occurs, then the IPI will never
- * be sent, and CPU 0's TLB will contain a stale entry.)
- *
- * The bad outcome can occur if either CPU's load is
- * reordered before that CPU's store, so both CPUs must
- * execute full barriers to prevent this from happening.
- *
- * Thus, switch_mm needs a full barrier between the
- * store to mm_cpumask and any operation that could load
- * from next->pgd. TLB fills are special and can happen
- * due to instruction fetches or for no reason at all,
- * and neither LOCK nor MFENCE orders them.
- * Fortunately, load_cr3() is serializing and gives the
- * ordering guarantee we need.
- *
- */
- load_cr3(next->pgd);
-
- trace_tlb_flush(TLB_FLUSH_ON_TASK_SWITCH, TLB_FLUSH_ALL);
-
- /* Stop flush ipis for the previous mm */
- cpumask_clear_cpu(cpu, mm_cpumask(prev));
+extern void switch_mm(struct mm_struct *prev, struct mm_struct *next,
+ struct task_struct *tsk);
- /* Load per-mm CR4 state */
- load_mm_cr4(next);
-
-#ifdef CONFIG_MODIFY_LDT_SYSCALL
- /*
- * Load the LDT, if the LDT is different.
- *
- * It's possible that prev->context.ldt doesn't match
- * the LDT register. This can happen if leave_mm(prev)
- * was called and then modify_ldt changed
- * prev->context.ldt but suppressed an IPI to this CPU.
- * In this case, prev->context.ldt != NULL, because we
- * never set context.ldt to NULL while the mm still
- * exists. That means that next->context.ldt !=
- * prev->context.ldt, because mms never share an LDT.
- */
- if (unlikely(prev->context.ldt != next->context.ldt))
- load_mm_ldt(next);
-#endif
- }
-#ifdef CONFIG_SMP
- else {
- this_cpu_write(cpu_tlbstate.state, TLBSTATE_OK);
- BUG_ON(this_cpu_read(cpu_tlbstate.active_mm) != next);
-
- if (!cpumask_test_cpu(cpu, mm_cpumask(next))) {
- /*
- * On established mms, the mm_cpumask is only changed
- * from irq context, from ptep_clear_flush() while in
- * lazy tlb mode, and here. Irqs are blocked during
- * schedule, protecting us from simultaneous changes.
- */
- cpumask_set_cpu(cpu, mm_cpumask(next));
-
- /*
- * We were in lazy tlb mode and leave_mm disabled
- * tlb flush IPI delivery. We must reload CR3
- * to make sure to use no freed page tables.
- *
- * As above, load_cr3() is serializing and orders TLB
- * fills with respect to the mm_cpumask write.
- */
- load_cr3(next->pgd);
- trace_tlb_flush(TLB_FLUSH_ON_TASK_SWITCH, TLB_FLUSH_ALL);
- load_mm_cr4(next);
- load_mm_ldt(next);
- }
- }
-#endif
-}
+extern void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next,
+ struct task_struct *tsk);
+#define switch_mm_irqs_off switch_mm_irqs_off
#define activate_mm(prev, next) \
do { \