Merge tag 'timers-v7.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/daniel.lezcano/linux into timers/clocksource

  - Use designated initializers for sh_mtu2, sh_cmt, and sh_tmu, and
    drop the unused initializer in the platform_device_id table for
    sh_mtu2 (Uwe Kleine-König)

  - Remove redundant dev_err()/dev_err_probe() messages when
    devm_request_*_irq() fails, as the helper already logs an error
    message (Pan Chuang)

  - Fix a boot hang on Allwinner D1 when a forced minimum delta is used
    with the sun4i timer (Felix Yan)

  - Fix an IRQ leak in the cpuhp_setup_state() error path by freeing the
    IRQ on failure in the NXP PIT driver (WenTao Liang)

  - Fix incorrect unmapping of shared MMIO between the clocksource and
    clockevent drivers. If one of them fails to initialize, the error
    path unmaps the shared MMIO region, leaving the other driver with an
    invalid mapping on clps711x (Guangshuo Li)

  - Make the samsung_pwm driver compatible with PREEMPT_RT by replacing
    regular spinlocks with raw_spinlock_t in atomic contexts (Marek
    Szyprowski)

  - Use __raw_readl() and __raw_writel() instead of ioread32() and
    iowrite32() to support SWAP_IO_SPACE in the rtl-otto driver (Rustam
    Adilov)

  - Fix a missing clk_disable_unprepare() call in the timer
    initialization error path of the Armada driver (Yuho Choi)

Link: https://lore.kernel.org/lkml/75feea31-683d-45a1-87f4-ab045e0152ae@oss.qualcomm.com

1 files changed, 89 insertions, 12 deletions

diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
index cdd68ed3ae1a..2981e386da7b 100644
--- a/include/linux/pgtable.h
+++ b/include/linux/pgtable.h
@@ -301,6 +301,28 @@ static inline void lazy_mmu_mode_disable(void)
 }
 
 /**
+ * __task_lazy_mmu_mode_pause() - Pause the lazy MMU mode for a task.
+ * @tsk: The task to check.
+ *
+ * Pauses the lazy MMU mode of @tsk.
+ *
+ * This function only operates on the state saved in task_struct; to pause
+ * current lazy_mmu_mode_pause() should be used instead.
+ *
+ * This function is intended for architectures that implement the lazy MMU
+ * mode; it must not be called from generic code.
+ */
+static inline void __task_lazy_mmu_mode_pause(struct task_struct *tsk)
+{
+	struct lazy_mmu_state *state = &tsk->lazy_mmu_state;
+
+	VM_WARN_ON_ONCE(state->pause_count == U8_MAX);
+
+	if (state->pause_count++ == 0 && state->enable_count > 0)
+		arch_leave_lazy_mmu_mode();
+}
+
+/**
  * lazy_mmu_mode_pause() - Pause the lazy MMU mode.
  *
  * Pauses the lazy MMU mode; if it is currently active, disables it and calls
@@ -315,15 +337,32 @@ static inline void lazy_mmu_mode_disable(void)
  */
 static inline void lazy_mmu_mode_pause(void)
 {
-	struct lazy_mmu_state *state = &current->lazy_mmu_state;
-
 	if (in_interrupt())
 		return;
 
-	VM_WARN_ON_ONCE(state->pause_count == U8_MAX);
+	__task_lazy_mmu_mode_pause(current);
+}
 
-	if (state->pause_count++ == 0 && state->enable_count > 0)
-		arch_leave_lazy_mmu_mode();
+/**
+ * __task_lazy_mmu_mode_resume() - Resume the lazy MMU mode for a task.
+ * @tsk: The task to check.
+ *
+ * Resumes the lazy MMU mode of @tsk.
+ *
+ * This function only operates on the state saved in task_struct; to resume
+ * current lazy_mmu_mode_resume() should be used instead.
+ *
+ * This function is intended for architectures that implement the lazy MMU
+ * mode; it must not be called from generic code.
+ */
+static inline void __task_lazy_mmu_mode_resume(struct task_struct *tsk)
+{
+	struct lazy_mmu_state *state = &tsk->lazy_mmu_state;
+
+	VM_WARN_ON_ONCE(state->pause_count == 0);
+
+	if (--state->pause_count == 0 && state->enable_count > 0)
+		arch_enter_lazy_mmu_mode();
 }
 
 /**
@@ -341,15 +380,10 @@ static inline void lazy_mmu_mode_pause(void)
  */
 static inline void lazy_mmu_mode_resume(void)
 {
-	struct lazy_mmu_state *state = &current->lazy_mmu_state;
-
 	if (in_interrupt())
 		return;
 
-	VM_WARN_ON_ONCE(state->pause_count == 0);
-
-	if (--state->pause_count == 0 && state->enable_count > 0)
-		arch_enter_lazy_mmu_mode();
+	__task_lazy_mmu_mode_resume(current);
 }
 #else
 static inline void lazy_mmu_mode_enable(void) {}
@@ -1036,6 +1070,49 @@ static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addres
 }
 #endif
 
+#ifndef ptep_try_set
+/**
+ * ptep_try_set - atomically set an empty kernel PTE
+ * @ptep: page table entry
+ * @new_pte: value to install
+ *
+ * Atomically set *@ptep to @new_pte iff *@ptep is pte_none(). Return true on
+ * success, false if the slot was already populated or the arch has no
+ * implementation.
+ *
+ * For special kernel page tables only - never user page tables. The caller must
+ * prevent concurrent teardown of @ptep and must accept that other writers may
+ * race. Concurrent clearers must use ptep_get_and_clear() so racing accesses
+ * agree on the outcome.
+ *
+ * Architectures opt in by providing a cmpxchg-based override and defining
+ * ptep_try_set as an identity macro. The generic stub returns false, which is
+ * correct for callers that fall through to oops on failure.
+ */
+static inline bool ptep_try_set(pte_t *ptep, pte_t new_pte)
+{
+	return false;
+}
+#endif
+
+#ifndef flush_tlb_before_set
+/**
+ * flush_tlb_before_set - invalidate a kernel PTE's TLB before re-setting it
+ * @addr: kernel virtual address whose PTE was just cleared
+ *
+ * Some architectures (e.g. arm64) do not allow a live page-table entry to be
+ * repointed at a different page in one step. The old entry must first be made
+ * invalid and its translation flushed from every TLB, and only then may the new
+ * entry be written.
+ *
+ * This is only for the lockless atomic kernel-PTE installers (ptep_try_set()).
+ * It must be callable with interrupts disabled.
+ */
+static inline void flush_tlb_before_set(unsigned long addr)
+{
+}
+#endif
+
 #ifndef wrprotect_ptes
 /**
  * wrprotect_ptes - Write-protect PTEs that map consecutive pages of the same
@@ -1993,7 +2070,7 @@ static inline unsigned long zero_pfn(unsigned long addr)
 	return zero_page_pfn;
 }
 
-extern uint8_t empty_zero_page[PAGE_SIZE];
+extern const uint8_t empty_zero_page[PAGE_SIZE];
 extern struct page *__zero_page;
 
 static inline struct page *_zero_page(unsigned long addr)