Merge branch 'docs-next' of git://git.lwn.net/linux into patchwork

* 'docs-next' of git://git.lwn.net/linux: (888 commits)
  w1_netlink.h: add support for nested structs
  scripts: kernel-doc: apply filtering rules to warnings
  scripts: kernel-doc: improve nested logic to handle multiple identifiers
  scripts: kernel-doc: handle nested struct function arguments
  scripts: kernel-doc: print the declaration name on warnings
  scripts: kernel-doc: get rid of $nested parameter
  scripts: kernel-doc: parse next structs/unions
  scripts: kernel-doc: replace tabs by spaces
  scripts: kernel-doc: change default to ReST format
  scripts: kernel-doc: improve argument handling
  scripts: kernel-doc: get rid of unused output formats
  docs: get rid of kernel-doc-nano-HOWTO.txt
  docs: kernel-doc.rst: add documentation about man pages
  docs: kernel-doc.rst: improve typedef documentation
  docs: kernel-doc.rst: improve structs chapter
  docs: kernel-doc.rst: improve function documentation section
  docs: kernel-doc.rst: improve private members description
  docs: kernel-doc.rst: better describe kernel-doc arguments
  docs: fix process/submit-checklist.rst Sphinx warning
  docs: ftrace-uses.rst fix varios code-block directives
  ...

1 files changed, 23 insertions, 23 deletions

diff --git a/arch/arm64/include/asm/mmu_context.h b/arch/arm64/include/asm/mmu_context.h
index 3257895a9b5e..9d155fa9a507 100644
--- a/arch/arm64/include/asm/mmu_context.h
+++ b/arch/arm64/include/asm/mmu_context.h
@@ -156,29 +156,21 @@ void check_and_switch_context(struct mm_struct *mm, unsigned int cpu);
 
 #define init_new_context(tsk,mm)	({ atomic64_set(&(mm)->context.id, 0); 0; })
 
-/*
- * This is called when "tsk" is about to enter lazy TLB mode.
- *
- * mm:  describes the currently active mm context
- * tsk: task which is entering lazy tlb
- * cpu: cpu number which is entering lazy tlb
- *
- * tsk->mm will be NULL
- */
-static inline void
-enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
-{
-}
-
 #ifdef CONFIG_ARM64_SW_TTBR0_PAN
 static inline void update_saved_ttbr0(struct task_struct *tsk,
 				      struct mm_struct *mm)
 {
-	if (system_uses_ttbr0_pan()) {
-		BUG_ON(mm->pgd == swapper_pg_dir);
-		task_thread_info(tsk)->ttbr0 =
-			virt_to_phys(mm->pgd) | ASID(mm) << 48;
-	}
+	u64 ttbr;
+
+	if (!system_uses_ttbr0_pan())
+		return;
+
+	if (mm == &init_mm)
+		ttbr = __pa_symbol(empty_zero_page);
+	else
+		ttbr = virt_to_phys(mm->pgd) | ASID(mm) << 48;
+
+	task_thread_info(tsk)->ttbr0 = ttbr;
 }
 #else
 static inline void update_saved_ttbr0(struct task_struct *tsk,
@@ -187,6 +179,16 @@ static inline void update_saved_ttbr0(struct task_struct *tsk,
 }
 #endif
 
+static inline void
+enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
+{
+	/*
+	 * We don't actually care about the ttbr0 mapping, so point it at the
+	 * zero page.
+	 */
+	update_saved_ttbr0(tsk, &init_mm);
+}
+
 static inline void __switch_mm(struct mm_struct *next)
 {
 	unsigned int cpu = smp_processor_id();
@@ -214,11 +216,9 @@ switch_mm(struct mm_struct *prev, struct mm_struct *next,
 	 * Update the saved TTBR0_EL1 of the scheduled-in task as the previous
 	 * value may have not been initialised yet (activate_mm caller) or the
 	 * ASID has changed since the last run (following the context switch
-	 * of another thread of the same process). Avoid setting the reserved
-	 * TTBR0_EL1 to swapper_pg_dir (init_mm; e.g. via idle_task_exit).
+	 * of another thread of the same process).
 	 */
-	if (next != &init_mm)
-		update_saved_ttbr0(tsk, next);
+	update_saved_ttbr0(tsk, next);
 }
 
 #define deactivate_mm(tsk,mm)	do { } while (0)