[PATCH 04/13] s390: mmu_gather rework

Peter Zijlstra
2011-03-02T17:55:03Z

[-- Attachment #1: martin_schwidefsky-s390-preemptible_mmu_gather.patch --]
[-- Type: text/plain, Size: 4126 bytes --]

From: Martin Schwidefsky <schwidefsky@de.ibm.com>

Adapt the stand-alone s390 mmu_gather implementation to the new
preemptible mmu_gather interface.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20101126145410.881573395@chello.nl>
---
arch/s390/include/asm/tlb.h | 60 ++++++++++++++++++++++++++------------------
1 file changed, 36 insertions(+), 24 deletions(-)

Index: linux-2.6/arch/s390/include/asm/tlb.h
===================================================================
--- linux-2.6.orig/arch/s390/include/asm/tlb.h
+++ linux-2.6/arch/s390/include/asm/tlb.h
@@ -29,58 +29,64 @@
#include <asm/smp.h>
#include <asm/tlbflush.h>

-#ifndef CONFIG_SMP
-#define TLB_NR_PTRS 1
-#else
-#define TLB_NR_PTRS 508
-#endif
-
struct mmu_gather {
struct mm_struct *mm;
unsigned int fullmm;
unsigned int nr_ptes;
unsigned int nr_pxds;
- void *array[TLB_NR_PTRS];
+ unsigned int max;
+ void **array;
+ void *local[8];
};

-DECLARE_PER_CPU(struct mmu_gather, mmu_gathers);
-
-static inline struct mmu_gather *tlb_gather_mmu(struct mm_struct *mm,
- unsigned int full_mm_flush)
+static inline void __tlb_alloc_page(struct mmu_gather *tlb)
{
- struct mmu_gather *tlb = &get_cpu_var(mmu_gathers);
+ unsigned long addr = __get_free_pages(GFP_NOWAIT | __GFP_NOWARN, 0);

+ if (addr) {
+ tlb->array = (void *) addr;
+ tlb->max = PAGE_SIZE / sizeof(void *);
+ }
+}
+
+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->nr_ptes = 0;
- tlb->nr_pxds = TLB_NR_PTRS;
if (tlb->fullmm)
__tlb_flush_mm(mm);
- return tlb;
+ else
+ __tlb_alloc_page(tlb);
+ tlb->nr_ptes = 0;
+ tlb->nr_pxds = tlb->max;
}

-static inline void tlb_flush_mmu(struct mmu_gather *tlb,
- unsigned long start, unsigned long end)
+static inline void tlb_flush_mmu(struct mmu_gather *tlb)
{
- if (!tlb->fullmm && (tlb->nr_ptes > 0 || tlb->nr_pxds < TLB_NR_PTRS))
+ 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_NR_PTRS)
+ while (tlb->nr_pxds < tlb->max)
crst_table_free_rcu(tlb->mm, tlb->array[tlb->nr_pxds++]);
}

static inline void tlb_finish_mmu(struct mmu_gather *tlb,
unsigned long start, unsigned long end)
{
- tlb_flush_mmu(tlb, start, end);
+ tlb_flush_mmu(tlb);

rcu_table_freelist_finish();

/* keep the page table cache within bounds */
check_pgt_cache();

- put_cpu_var(mmu_gathers);
+ if (tlb->array != tlb->local)
+ free_pages((unsigned long) tlb->array, 0);
}

/*
@@ -88,6 +94,12 @@ static inline void tlb_finish_mmu(struct
* tlb_ptep_clear_flush. In both flush modes the tlb fo a page cache page
* has already been freed, so just do free_page_and_swap_cache.
*/
+static inline int __tlb_remove_page(struct mmu_gather *tlb, struct page *page)
+{
+ free_page_and_swap_cache(page);
+ return 0;
+}
+
static inline void tlb_remove_page(struct mmu_gather *tlb, struct page *page)
{
free_page_and_swap_cache(page);
@@ -103,7 +115,7 @@ static inline void pte_free_tlb(struct m
if (!tlb->fullmm) {
tlb->array[tlb->nr_ptes++] = pte;
if (tlb->nr_ptes >= tlb->nr_pxds)
- tlb_flush_mmu(tlb, 0, 0);
+ tlb_flush_mmu(tlb);
} else
page_table_free(tlb->mm, (unsigned long *) pte);
}
@@ -124,7 +136,7 @@ static inline void pmd_free_tlb(struct m
if (!tlb->fullmm) {
tlb->array[--tlb->nr_pxds] = pmd;
if (tlb->nr_ptes >= tlb->nr_pxds)
- tlb_flush_mmu(tlb, 0, 0);
+ tlb_flush_mmu(tlb);
} else
crst_table_free(tlb->mm, (unsigned long *) pmd);
#endif
@@ -146,7 +158,7 @@ static inline void pud_free_tlb(struct m
if (!tlb->fullmm) {
tlb->array[--tlb->nr_pxds] = pud;
if (tlb->nr_ptes >= tlb->nr_pxds)
- tlb_flush_mmu(tlb, 0, 0);
+ tlb_flush_mmu(tlb);
} else
crst_table_free(tlb->mm, (unsigned long *) pud);
#endif