[SPARC64]: Avoid dcache-dirty page state management on sun4v.
[linux-2.6.git] / arch / sparc64 / mm / tlb.c
1 /* arch/sparc64/mm/tlb.c
2  *
3  * Copyright (C) 2004 David S. Miller <davem@redhat.com>
4  */
5
6 #include <linux/kernel.h>
7 #include <linux/init.h>
8 #include <linux/percpu.h>
9 #include <linux/mm.h>
10 #include <linux/swap.h>
11
12 #include <asm/pgtable.h>
13 #include <asm/pgalloc.h>
14 #include <asm/tlbflush.h>
15 #include <asm/cacheflush.h>
16 #include <asm/mmu_context.h>
17 #include <asm/tlb.h>
18
19 /* Heavily inspired by the ppc64 code.  */
20
21 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers) = { 0, };
22
23 void flush_tlb_pending(void)
24 {
25         struct mmu_gather *mp = &__get_cpu_var(mmu_gathers);
26
27         if (mp->tlb_nr) {
28                 flush_tsb_user(mp);
29
30                 if (CTX_VALID(mp->mm->context)) {
31 #ifdef CONFIG_SMP
32                         smp_flush_tlb_pending(mp->mm, mp->tlb_nr,
33                                               &mp->vaddrs[0]);
34 #else
35                         __flush_tlb_pending(CTX_HWBITS(mp->mm->context),
36                                             mp->tlb_nr, &mp->vaddrs[0]);
37 #endif
38                 }
39                 mp->tlb_nr = 0;
40         }
41 }
42
43 void tlb_batch_add(struct mm_struct *mm, unsigned long vaddr, pte_t *ptep, pte_t orig)
44 {
45         struct mmu_gather *mp = &__get_cpu_var(mmu_gathers);
46         unsigned long nr;
47
48         vaddr &= PAGE_MASK;
49         if (pte_exec(orig))
50                 vaddr |= 0x1UL;
51
52         if (tlb_type != hypervisor &&
53             pte_dirty(orig)) {
54                 unsigned long paddr, pfn = pte_pfn(orig);
55                 struct address_space *mapping;
56                 struct page *page;
57
58                 if (!pfn_valid(pfn))
59                         goto no_cache_flush;
60
61                 page = pfn_to_page(pfn);
62                 if (PageReserved(page))
63                         goto no_cache_flush;
64
65                 /* A real file page? */
66                 mapping = page_mapping(page);
67                 if (!mapping)
68                         goto no_cache_flush;
69
70                 paddr = (unsigned long) page_address(page);
71                 if ((paddr ^ vaddr) & (1 << 13))
72                         flush_dcache_page_all(mm, page);
73         }
74
75 no_cache_flush:
76
77         if (mp->fullmm)
78                 return;
79
80         nr = mp->tlb_nr;
81
82         if (unlikely(nr != 0 && mm != mp->mm)) {
83                 flush_tlb_pending();
84                 nr = 0;
85         }
86
87         if (nr == 0)
88                 mp->mm = mm;
89
90         mp->vaddrs[nr] = vaddr;
91         mp->tlb_nr = ++nr;
92         if (nr >= TLB_BATCH_NR)
93                 flush_tlb_pending();
94 }