[S390] use generic RCU page-table freeing code
Replace the s390 specific rcu page-table freeing code with the
generic variant. This requires to duplicate the definition for the
struct mmu_table_batch as s390 does not use the generic tlb flush
code.
While we are at it remove the restriction that page table fragments
can not be reused after a single fragment has been freed with rcu
and split out allocation and freeing of page tables with pgstes.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/include/asm/pgalloc.h b/arch/s390/include/asm/pgalloc.h
index f6314af..38e71eb 100644
--- a/arch/s390/include/asm/pgalloc.h
+++ b/arch/s390/include/asm/pgalloc.h
@@ -17,15 +17,15 @@
#include <linux/gfp.h>
#include <linux/mm.h>
-#define check_pgt_cache() do {} while (0)
-
unsigned long *crst_table_alloc(struct mm_struct *);
void crst_table_free(struct mm_struct *, unsigned long *);
-void crst_table_free_rcu(struct mm_struct *, unsigned long *);
unsigned long *page_table_alloc(struct mm_struct *);
void page_table_free(struct mm_struct *, unsigned long *);
-void page_table_free_rcu(struct mm_struct *, unsigned long *);
+#ifdef CONFIG_HAVE_RCU_TABLE_FREE
+void page_table_free_rcu(struct mmu_gather *, unsigned long *);
+void __tlb_remove_table(void *_table);
+#endif
static inline void clear_table(unsigned long *s, unsigned long val, size_t n)
{
diff --git a/arch/s390/include/asm/tlb.h b/arch/s390/include/asm/tlb.h
index 77eee54..c687a2c 100644
--- a/arch/s390/include/asm/tlb.h
+++ b/arch/s390/include/asm/tlb.h
@@ -26,67 +26,60 @@
#include <linux/swap.h>
#include <asm/processor.h>
#include <asm/pgalloc.h>
-#include <asm/smp.h>
#include <asm/tlbflush.h>
struct mmu_gather {
struct mm_struct *mm;
+#ifdef CONFIG_HAVE_RCU_TABLE_FREE
+ struct mmu_table_batch *batch;
+#endif
unsigned int fullmm;
- unsigned int nr_ptes;
- unsigned int nr_pxds;
- unsigned int max;
- void **array;
- void *local[8];
+ unsigned int need_flush;
};
-static inline void __tlb_alloc_page(struct mmu_gather *tlb)
-{
- unsigned long addr = __get_free_pages(GFP_NOWAIT | __GFP_NOWARN, 0);
+#ifdef CONFIG_HAVE_RCU_TABLE_FREE
+struct mmu_table_batch {
+ struct rcu_head rcu;
+ unsigned int nr;
+ void *tables[0];
+};
- if (addr) {
- tlb->array = (void *) addr;
- tlb->max = PAGE_SIZE / sizeof(void *);
- }
-}
+#define MAX_TABLE_BATCH \
+ ((PAGE_SIZE - sizeof(struct mmu_table_batch)) / sizeof(void *))
+
+extern void tlb_table_flush(struct mmu_gather *tlb);
+extern void tlb_remove_table(struct mmu_gather *tlb, void *table);
+#endif
static inline void tlb_gather_mmu(struct mmu_gather *tlb,
struct mm_struct *mm,
unsigned int full_mm_flush)
{
tlb->mm = mm;
- tlb->max = ARRAY_SIZE(tlb->local);
- tlb->array = tlb->local;
tlb->fullmm = full_mm_flush;
+ tlb->need_flush = 0;
+#ifdef CONFIG_HAVE_RCU_TABLE_FREE
+ tlb->batch = NULL;
+#endif
if (tlb->fullmm)
__tlb_flush_mm(mm);
- else
- __tlb_alloc_page(tlb);
- tlb->nr_ptes = 0;
- tlb->nr_pxds = tlb->max;
}
static inline void tlb_flush_mmu(struct mmu_gather *tlb)
{
- if (!tlb->fullmm && (tlb->nr_ptes > 0 || tlb->nr_pxds < tlb->max))
- __tlb_flush_mm(tlb->mm);
- while (tlb->nr_ptes > 0)
- page_table_free_rcu(tlb->mm, tlb->array[--tlb->nr_ptes]);
- while (tlb->nr_pxds < tlb->max)
- crst_table_free_rcu(tlb->mm, tlb->array[tlb->nr_pxds++]);
+ if (!tlb->need_flush)
+ return;
+ tlb->need_flush = 0;
+ __tlb_flush_mm(tlb->mm);
+#ifdef CONFIG_HAVE_RCU_TABLE_FREE
+ tlb_table_flush(tlb);
+#endif
}
static inline void tlb_finish_mmu(struct mmu_gather *tlb,
unsigned long start, unsigned long end)
{
tlb_flush_mmu(tlb);
-
- rcu_table_freelist_finish();
-
- /* keep the page table cache within bounds */
- check_pgt_cache();
-
- if (tlb->array != tlb->local)
- free_pages((unsigned long) tlb->array, 0);
}
/*
@@ -112,12 +105,11 @@
static inline void pte_free_tlb(struct mmu_gather *tlb, pgtable_t pte,
unsigned long address)
{
- if (!tlb->fullmm) {
- tlb->array[tlb->nr_ptes++] = pte;
- if (tlb->nr_ptes >= tlb->nr_pxds)
- tlb_flush_mmu(tlb);
- } else
- page_table_free(tlb->mm, (unsigned long *) pte);
+#ifdef CONFIG_HAVE_RCU_TABLE_FREE
+ if (!tlb->fullmm)
+ return page_table_free_rcu(tlb, (unsigned long *) pte);
+#endif
+ page_table_free(tlb->mm, (unsigned long *) pte);
}
/*
@@ -133,12 +125,11 @@
#ifdef __s390x__
if (tlb->mm->context.asce_limit <= (1UL << 31))
return;
- if (!tlb->fullmm) {
- tlb->array[--tlb->nr_pxds] = pmd;
- if (tlb->nr_ptes >= tlb->nr_pxds)
- tlb_flush_mmu(tlb);
- } else
- crst_table_free(tlb->mm, (unsigned long *) pmd);
+#ifdef CONFIG_HAVE_RCU_TABLE_FREE
+ if (!tlb->fullmm)
+ return tlb_remove_table(tlb, pmd);
+#endif
+ crst_table_free(tlb->mm, (unsigned long *) pmd);
#endif
}
@@ -155,12 +146,11 @@
#ifdef __s390x__
if (tlb->mm->context.asce_limit <= (1UL << 42))
return;
- if (!tlb->fullmm) {
- tlb->array[--tlb->nr_pxds] = pud;
- if (tlb->nr_ptes >= tlb->nr_pxds)
- tlb_flush_mmu(tlb);
- } else
- crst_table_free(tlb->mm, (unsigned long *) pud);
+#ifdef CONFIG_HAVE_RCU_TABLE_FREE
+ if (!tlb->fullmm)
+ return tlb_remove_table(tlb, pud);
+#endif
+ crst_table_free(tlb->mm, (unsigned long *) pud);
#endif
}