xref: /openbmc/linux/arch/sparc/mm/tlb.c (revision ecba1060)
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 #include <linux/preempt.h>
12 
13 #include <asm/pgtable.h>
14 #include <asm/pgalloc.h>
15 #include <asm/tlbflush.h>
16 #include <asm/cacheflush.h>
17 #include <asm/mmu_context.h>
18 #include <asm/tlb.h>
19 
20 /* Heavily inspired by the ppc64 code.  */
21 
22 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
23 
24 void flush_tlb_pending(void)
25 {
26 	struct mmu_gather *mp = &get_cpu_var(mmu_gathers);
27 
28 	if (mp->tlb_nr) {
29 		flush_tsb_user(mp);
30 
31 		if (CTX_VALID(mp->mm->context)) {
32 #ifdef CONFIG_SMP
33 			smp_flush_tlb_pending(mp->mm, mp->tlb_nr,
34 					      &mp->vaddrs[0]);
35 #else
36 			__flush_tlb_pending(CTX_HWBITS(mp->mm->context),
37 					    mp->tlb_nr, &mp->vaddrs[0]);
38 #endif
39 		}
40 		mp->tlb_nr = 0;
41 	}
42 
43 	put_cpu_var(mmu_gathers);
44 }
45 
46 void tlb_batch_add(struct mm_struct *mm, unsigned long vaddr, pte_t *ptep, pte_t orig)
47 {
48 	struct mmu_gather *mp = &__get_cpu_var(mmu_gathers);
49 	unsigned long nr;
50 
51 	vaddr &= PAGE_MASK;
52 	if (pte_exec(orig))
53 		vaddr |= 0x1UL;
54 
55 	if (tlb_type != hypervisor &&
56 	    pte_dirty(orig)) {
57 		unsigned long paddr, pfn = pte_pfn(orig);
58 		struct address_space *mapping;
59 		struct page *page;
60 
61 		if (!pfn_valid(pfn))
62 			goto no_cache_flush;
63 
64 		page = pfn_to_page(pfn);
65 		if (PageReserved(page))
66 			goto no_cache_flush;
67 
68 		/* A real file page? */
69 		mapping = page_mapping(page);
70 		if (!mapping)
71 			goto no_cache_flush;
72 
73 		paddr = (unsigned long) page_address(page);
74 		if ((paddr ^ vaddr) & (1 << 13))
75 			flush_dcache_page_all(mm, page);
76 	}
77 
78 no_cache_flush:
79 
80 	if (mp->fullmm)
81 		return;
82 
83 	nr = mp->tlb_nr;
84 
85 	if (unlikely(nr != 0 && mm != mp->mm)) {
86 		flush_tlb_pending();
87 		nr = 0;
88 	}
89 
90 	if (nr == 0)
91 		mp->mm = mm;
92 
93 	mp->vaddrs[nr] = vaddr;
94 	mp->tlb_nr = ++nr;
95 	if (nr >= TLB_BATCH_NR)
96 		flush_tlb_pending();
97 }
98