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-rw-r--r--arch/cris/arch-v10/mm/tlb.c248
1 files changed, 248 insertions, 0 deletions
diff --git a/arch/cris/arch-v10/mm/tlb.c b/arch/cris/arch-v10/mm/tlb.c
new file mode 100644
index 000000000000..9d06125ff5a2
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+++ b/arch/cris/arch-v10/mm/tlb.c
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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 */
12
13#include <asm/tlb.h>
14#include <asm/mmu_context.h>
15#include <asm/arch/svinto.h>
16
17#define D(x)
18
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 */
32
33/* invalidate all TLB entries */
34
35void
36flush_tlb_all(void)
37{
38 int i;
39 unsigned long flags;
40
41 /* the vpn of i & 0xf is so we dont write similar TLB entries
42 * in the same 4-way entry group. details..
43 */
44
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 ) );
51
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}
61
62/* invalidate the selected mm context only */
63
64void
65flush_tlb_mm(struct mm_struct *mm)
66{
67 int i;
68 int page_id = mm->context.page_id;
69 unsigned long flags;
70
71 D(printk("tlb: flush mm context %d (%p)\n", page_id, mm));
72
73 if(page_id == NO_CONTEXT)
74 return;
75
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 */
80
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 ) );
88
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}
98
99/* invalidate a single page */
100
101void
102flush_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;
109
110 D(printk("tlb: flush page %p in context %d (%p)\n", addr, page_id, mm));
111
112 if(page_id == NO_CONTEXT)
113 return;
114
115 addr &= PAGE_MASK; /* perhaps not necessary */
116
117 /* invalidate those TLB entries that match both the mm context
118 * and the virtual address requested
119 */
120
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. */
131
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}
141
142/* invalidate a page range */
143
144void
145flush_tlb_range(struct vm_area_struct *vma,
146 unsigned long start,
147 unsigned long end)
148{
149 struct mm_struct *mm = vma->vm_mm;
150 int page_id = mm->context.page_id;
151 int i;
152 unsigned long flags;
153
154 D(printk("tlb: flush range %p<->%p in context %d (%p)\n",
155 start, end, page_id, mm));
156
157 if(page_id == NO_CONTEXT)
158 return;
159
160 start &= PAGE_MASK; /* probably not necessary */
161 end &= PAGE_MASK; /* dito */
162
163 /* invalidate those TLB entries that match both the mm context
164 * and the virtual address range
165 */
166
167 local_save_flags(flags);
168 local_irq_disable();
169 for(i = 0; i < NUM_TLB_ENTRIES; i++) {
170 unsigned long tlb_hi, vpn;
171 *R_TLB_SELECT = IO_FIELD(R_TLB_SELECT, index, i);
172 tlb_hi = *R_TLB_HI;
173 vpn = tlb_hi & PAGE_MASK;
174 if (IO_EXTRACT(R_TLB_HI, page_id, tlb_hi) == page_id &&
175 vpn >= start && vpn < end) {
176 *R_TLB_HI = ( IO_FIELD(R_TLB_HI, page_id, INVALID_PAGEID ) |
177 IO_FIELD(R_TLB_HI, vpn, i & 0xf ) );
178
179 *R_TLB_LO = ( IO_STATE(R_TLB_LO, global,no ) |
180 IO_STATE(R_TLB_LO, valid, no ) |
181 IO_STATE(R_TLB_LO, kernel,no ) |
182 IO_STATE(R_TLB_LO, we, no ) |
183 IO_FIELD(R_TLB_LO, pfn, 0 ) );
184 }
185 }
186 local_irq_restore(flags);
187}
188
189/* dump the entire TLB for debug purposes */
190
191#if 0
192void
193dump_tlb_all(void)
194{
195 int i;
196 unsigned long flags;
197
198 printk("TLB dump. LO is: pfn | reserved | global | valid | kernel | we |\n");
199
200 local_save_flags(flags);
201 local_irq_disable();
202 for(i = 0; i < NUM_TLB_ENTRIES; i++) {
203 *R_TLB_SELECT = ( IO_FIELD(R_TLB_SELECT, index, i) );
204 printk("Entry %d: HI 0x%08lx, LO 0x%08lx\n",
205 i, *R_TLB_HI, *R_TLB_LO);
206 }
207 local_irq_restore(flags);
208}
209#endif
210
211/*
212 * Initialize the context related info for a new mm_struct
213 * instance.
214 */
215
216int
217init_new_context(struct task_struct *tsk, struct mm_struct *mm)
218{
219 mm->context.page_id = NO_CONTEXT;
220 return 0;
221}
222
223/* called in schedule() just before actually doing the switch_to */
224
225void
226switch_mm(struct mm_struct *prev, struct mm_struct *next,
227 struct task_struct *tsk)
228{
229 /* make sure we have a context */
230
231 get_mmu_context(next);
232
233 /* remember the pgd for the fault handlers
234 * this is similar to the pgd register in some other CPU's.
235 * we need our own copy of it because current and active_mm
236 * might be invalid at points where we still need to derefer
237 * the pgd.
238 */
239
240 current_pgd = next->pgd;
241
242 /* switch context in the MMU */
243
244 D(printk("switching mmu_context to %d (%p)\n", next->context, next));
245
246 *R_MMU_CONTEXT = IO_FIELD(R_MMU_CONTEXT, page_id, next->context.page_id);
247}
248
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-12 07:15:51 -0500