ia64/linux-2.6.18-xen.hg

view arch/cris/arch-v10/mm/tlb.c @ 647:a5bb490065f6

Fix the build after public header sync.
Signed-off-by: Keir Fraser <keir.fraser@citrix.com>
author Keir Fraser <keir.fraser@citrix.com>
date Wed Aug 13 14:01:49 2008 +0100 (2008-08-13)
parents 831230e53067
children
line source
1 /*
2 * linux/arch/cris/arch-v10/mm/tlb.c
3 *
4 * Low level TLB handling
5 *
6 *
7 * Copyright (C) 2000-2002 Axis Communications AB
8 *
9 * Authors: Bjorn Wesen (bjornw@axis.com)
10 *
11 */
13 #include <asm/tlb.h>
14 #include <asm/mmu_context.h>
15 #include <asm/arch/svinto.h>
17 #define D(x)
19 /* The TLB can host up to 64 different mm contexts at the same time.
20 * The running context is R_MMU_CONTEXT, and each TLB entry contains a
21 * page_id that has to match to give a hit. In page_id_map, we keep track
22 * of which mm's we have assigned which page_id's, so that we know when
23 * to invalidate TLB entries.
24 *
25 * The last page_id is never running - it is used as an invalid page_id
26 * so we can make TLB entries that will never match.
27 *
28 * Notice that we need to make the flushes atomic, otherwise an interrupt
29 * handler that uses vmalloced memory might cause a TLB load in the middle
30 * of a flush causing.
31 */
33 /* invalidate all TLB entries */
35 void
36 flush_tlb_all(void)
37 {
38 int i;
39 unsigned long flags;
41 /* the vpn of i & 0xf is so we dont write similar TLB entries
42 * in the same 4-way entry group. details..
43 */
45 local_save_flags(flags);
46 local_irq_disable();
47 for(i = 0; i < NUM_TLB_ENTRIES; i++) {
48 *R_TLB_SELECT = ( IO_FIELD(R_TLB_SELECT, index, i) );
49 *R_TLB_HI = ( IO_FIELD(R_TLB_HI, page_id, INVALID_PAGEID ) |
50 IO_FIELD(R_TLB_HI, vpn, i & 0xf ) );
52 *R_TLB_LO = ( IO_STATE(R_TLB_LO, global,no ) |
53 IO_STATE(R_TLB_LO, valid, no ) |
54 IO_STATE(R_TLB_LO, kernel,no ) |
55 IO_STATE(R_TLB_LO, we, no ) |
56 IO_FIELD(R_TLB_LO, pfn, 0 ) );
57 }
58 local_irq_restore(flags);
59 D(printk("tlb: flushed all\n"));
60 }
62 /* invalidate the selected mm context only */
64 void
65 flush_tlb_mm(struct mm_struct *mm)
66 {
67 int i;
68 int page_id = mm->context.page_id;
69 unsigned long flags;
71 D(printk("tlb: flush mm context %d (%p)\n", page_id, mm));
73 if(page_id == NO_CONTEXT)
74 return;
76 /* mark the TLB entries that match the page_id as invalid.
77 * here we could also check the _PAGE_GLOBAL bit and NOT flush
78 * global pages. is it worth the extra I/O ?
79 */
81 local_save_flags(flags);
82 local_irq_disable();
83 for(i = 0; i < NUM_TLB_ENTRIES; i++) {
84 *R_TLB_SELECT = IO_FIELD(R_TLB_SELECT, index, i);
85 if (IO_EXTRACT(R_TLB_HI, page_id, *R_TLB_HI) == page_id) {
86 *R_TLB_HI = ( IO_FIELD(R_TLB_HI, page_id, INVALID_PAGEID ) |
87 IO_FIELD(R_TLB_HI, vpn, i & 0xf ) );
89 *R_TLB_LO = ( IO_STATE(R_TLB_LO, global,no ) |
90 IO_STATE(R_TLB_LO, valid, no ) |
91 IO_STATE(R_TLB_LO, kernel,no ) |
92 IO_STATE(R_TLB_LO, we, no ) |
93 IO_FIELD(R_TLB_LO, pfn, 0 ) );
94 }
95 }
96 local_irq_restore(flags);
97 }
99 /* invalidate a single page */
101 void
102 flush_tlb_page(struct vm_area_struct *vma,
103 unsigned long addr)
104 {
105 struct mm_struct *mm = vma->vm_mm;
106 int page_id = mm->context.page_id;
107 int i;
108 unsigned long flags;
110 D(printk("tlb: flush page %p in context %d (%p)\n", addr, page_id, mm));
112 if(page_id == NO_CONTEXT)
113 return;
115 addr &= PAGE_MASK; /* perhaps not necessary */
117 /* invalidate those TLB entries that match both the mm context
118 * and the virtual address requested
119 */
121 local_save_flags(flags);
122 local_irq_disable();
123 for(i = 0; i < NUM_TLB_ENTRIES; i++) {
124 unsigned long tlb_hi;
125 *R_TLB_SELECT = IO_FIELD(R_TLB_SELECT, index, i);
126 tlb_hi = *R_TLB_HI;
127 if (IO_EXTRACT(R_TLB_HI, page_id, tlb_hi) == page_id &&
128 (tlb_hi & PAGE_MASK) == addr) {
129 *R_TLB_HI = IO_FIELD(R_TLB_HI, page_id, INVALID_PAGEID ) |
130 addr; /* same addr as before works. */
132 *R_TLB_LO = ( IO_STATE(R_TLB_LO, global,no ) |
133 IO_STATE(R_TLB_LO, valid, no ) |
134 IO_STATE(R_TLB_LO, kernel,no ) |
135 IO_STATE(R_TLB_LO, we, no ) |
136 IO_FIELD(R_TLB_LO, pfn, 0 ) );
137 }
138 }
139 local_irq_restore(flags);
140 }
142 /* dump the entire TLB for debug purposes */
144 #if 0
145 void
146 dump_tlb_all(void)
147 {
148 int i;
149 unsigned long flags;
151 printk("TLB dump. LO is: pfn | reserved | global | valid | kernel | we |\n");
153 local_save_flags(flags);
154 local_irq_disable();
155 for(i = 0; i < NUM_TLB_ENTRIES; i++) {
156 *R_TLB_SELECT = ( IO_FIELD(R_TLB_SELECT, index, i) );
157 printk("Entry %d: HI 0x%08lx, LO 0x%08lx\n",
158 i, *R_TLB_HI, *R_TLB_LO);
159 }
160 local_irq_restore(flags);
161 }
162 #endif
164 /*
165 * Initialize the context related info for a new mm_struct
166 * instance.
167 */
169 int
170 init_new_context(struct task_struct *tsk, struct mm_struct *mm)
171 {
172 mm->context.page_id = NO_CONTEXT;
173 return 0;
174 }
176 /* called in schedule() just before actually doing the switch_to */
178 void
179 switch_mm(struct mm_struct *prev, struct mm_struct *next,
180 struct task_struct *tsk)
181 {
182 /* make sure we have a context */
184 get_mmu_context(next);
186 /* remember the pgd for the fault handlers
187 * this is similar to the pgd register in some other CPU's.
188 * we need our own copy of it because current and active_mm
189 * might be invalid at points where we still need to derefer
190 * the pgd.
191 */
193 per_cpu(current_pgd, smp_processor_id()) = next->pgd;
195 /* switch context in the MMU */
197 D(printk("switching mmu_context to %d (%p)\n", next->context, next));
199 *R_MMU_CONTEXT = IO_FIELD(R_MMU_CONTEXT, page_id, next->context.page_id);
200 }