Just like regular pages, page directories need to observe the
following order:
1) unhook
2) TLB invalidate
3) free
to ensure it is safe against concurrent accesses.
Because PARISC has non-page-size PMDs, use a custom table freeer.
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
---
arch/parisc/Kconfig | 1 +
arch/parisc/include/asm/pgalloc.h | 23 ++++++++++++++++++++---
arch/parisc/include/asm/tlb.h | 9 +++++----
3 files changed, 26 insertions(+), 7 deletions(-)
--- a/arch/parisc/Kconfig
+++ b/arch/parisc/Kconfig
@@ -63,6 +63,7 @@ config PARISC
select HAVE_KPROBES_ON_FTRACE
select HAVE_DYNAMIC_FTRACE_WITH_REGS
select HAVE_COPY_THREAD_TLS
+ select MMU_GATHER_TABLE_FREE if PGTABLE_LEVELS >= 3
help
The PA-RISC microprocessor is designed by Hewlett-Packard and used
--- a/arch/parisc/include/asm/pgalloc.h
+++ b/arch/parisc/include/asm/pgalloc.h
@@ -73,7 +73,7 @@ static inline pmd_t *pmd_alloc_one(struc
return pmd;
}
-static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
+static inline bool __pmd_free(struct mm_struct *mm, pmd_t *pmd)
{
if (pmd_flag(*pmd) & PxD_FLAG_ATTACHED) {
/*
@@ -83,11 +83,28 @@ static inline void pmd_free(struct mm_st
* done by generic mm code.
*/
mm_inc_nr_pmds(mm);
- return;
+ return false;
}
- free_pages((unsigned long)pmd, PMD_ORDER);
+ return true;
+}
+
+static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
+{
+ if (__pmd_free(mm, pmd))
+ free_pages((unsigned long)pmd, PMD_ORDER);
}
+static inline void __tlb_remove_table(void *table)
+{
+ free_pages((unsigned long)table, PMD_ORDER);
+}
+
+#define __pmd_free_tlb(tlb, pmd, addr) \
+do { \
+ if (__pmd_free((tlb)->mm, (pmd))) \
+ tlb_remove_table((tlb), (pmd)); \
+} while (0)
+
#endif
static inline void
--- a/arch/parisc/include/asm/tlb.h
+++ b/arch/parisc/include/asm/tlb.h
@@ -4,9 +4,10 @@
#include <asm-generic/tlb.h>
-#if CONFIG_PGTABLE_LEVELS == 3
-#define __pmd_free_tlb(tlb, pmd, addr) pmd_free((tlb)->mm, pmd)
-#endif
-#define __pte_free_tlb(tlb, pte, addr) pte_free((tlb)->mm, pte)
+#define __pte_free_tlb(tlb,pte,addr) \
+do { \
+ pgtable_pte_page_dtor(pte); \
+ tlb_remove_page((tlb), (pte)); \
+} while (0)
#endif
