Merge tag 'v6.15-rc1' into x86/mm, to pick up fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 8 insertions, 6 deletions

diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
index 4c107e17c547..e2b705c14945 100644
--- a/include/linux/pgtable.h
+++ b/include/linux/pgtable.h
@@ -222,10 +222,14 @@ static inline int pmd_dirty(pmd_t pmd)
  * hazard could result in the direct mode hypervisor case, since the actual
  * write to the page tables may not yet have taken place, so reads though
  * a raw PTE pointer after it has been modified are not guaranteed to be
- * up to date.  This mode can only be entered and left under the protection of
- * the page table locks for all page tables which may be modified.  In the UP
- * case, this is required so that preemption is disabled, and in the SMP case,
- * it must synchronize the delayed page table writes properly on other CPUs.
+ * up to date.
+ *
+ * In the general case, no lock is guaranteed to be held between entry and exit
+ * of the lazy mode. So the implementation must assume preemption may be enabled
+ * and cpu migration is possible; it must take steps to be robust against this.
+ * (In practice, for user PTE updates, the appropriate page table lock(s) are
+ * held, but for kernel PTE updates, no lock is held). Nesting is not permitted
+ * and the mode cannot be used in interrupt context.
  */
 #ifndef __HAVE_ARCH_ENTER_LAZY_MMU_MODE
 #define arch_enter_lazy_mmu_mode()	do {} while (0)
@@ -287,7 +291,6 @@ static inline void set_ptes(struct mm_struct *mm, unsigned long addr,
 {
 	page_table_check_ptes_set(mm, ptep, pte, nr);
 
-	arch_enter_lazy_mmu_mode();
 	for (;;) {
 		set_pte(ptep, pte);
 		if (--nr == 0)
@@ -295,7 +298,6 @@ static inline void set_ptes(struct mm_struct *mm, unsigned long addr,
 		ptep++;
 		pte = pte_next_pfn(pte);
 	}
-	arch_leave_lazy_mmu_mode();
 }
 #endif
 #define set_pte_at(mm, addr, ptep, pte) set_ptes(mm, addr, ptep, pte, 1)