1 /*
2 * r2300.c: R2000 and R3000 specific mmu/cache code.
3 *
4 * Copyright (C) 1996 David S. Miller (dm@engr.sgi.com)
5 *
6 * with a lot of changes to make this thing work for R3000s
7 * Tx39XX R4k style caches added. HK
8 * Copyright (C) 1998, 1999, 2000 Harald Koerfgen
9 * Copyright (C) 1998 Gleb Raiko & Vladimir Roganov
10 * Copyright (C) 2002 Ralf Baechle
11 * Copyright (C) 2002 Maciej W. Rozycki
12 */
13 #include <linux/init.h>
14 #include <linux/kernel.h>
15 #include <linux/sched.h>
16 #include <linux/smp.h>
17 #include <linux/mm.h>
18
19 #include <asm/page.h>
20 #include <asm/pgtable.h>
21 #include <asm/mmu_context.h>
22 #include <asm/system.h>
23 #include <asm/isadep.h>
24 #include <asm/io.h>
25 #include <asm/bootinfo.h>
26 #include <asm/cpu.h>
27
28 #undef DEBUG_TLB
29
30 extern void build_tlb_refill_handler(void);
31
32 /* CP0 hazard avoidance. */
33 #define BARRIER \
34 __asm__ __volatile__( \
35 ".set push\n\t" \
36 ".set noreorder\n\t" \
37 "nop\n\t" \
38 ".set pop\n\t")
39
40 int r3k_have_wired_reg; /* should be in cpu_data? */
41
42 /* TLB operations. */
local_flush_tlb_all(void)43 void local_flush_tlb_all(void)
44 {
45 unsigned long flags;
46 unsigned long old_ctx;
47 int entry;
48
49 #ifdef DEBUG_TLB
50 printk("[tlball]");
51 #endif
52
53 local_irq_save(flags);
54 old_ctx = read_c0_entryhi() & ASID_MASK;
55 write_c0_entrylo0(0);
56 entry = r3k_have_wired_reg ? read_c0_wired() : 8;
57 for (; entry < current_cpu_data.tlbsize; entry++) {
58 write_c0_index(entry << 8);
59 write_c0_entryhi((entry | 0x80000) << 12);
60 BARRIER;
61 tlb_write_indexed();
62 }
63 write_c0_entryhi(old_ctx);
64 local_irq_restore(flags);
65 }
66
local_flush_tlb_mm(struct mm_struct * mm)67 void local_flush_tlb_mm(struct mm_struct *mm)
68 {
69 int cpu = smp_processor_id();
70
71 if (cpu_context(cpu, mm) != 0) {
72 #ifdef DEBUG_TLB
73 printk("[tlbmm<%lu>]", (unsigned long)cpu_context(cpu, mm));
74 #endif
75 drop_mmu_context(mm, cpu);
76 }
77 }
78
local_flush_tlb_range(struct vm_area_struct * vma,unsigned long start,unsigned long end)79 void local_flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
80 unsigned long end)
81 {
82 struct mm_struct *mm = vma->vm_mm;
83 int cpu = smp_processor_id();
84
85 if (cpu_context(cpu, mm) != 0) {
86 unsigned long size, flags;
87
88 #ifdef DEBUG_TLB
89 printk("[tlbrange<%lu,0x%08lx,0x%08lx>]",
90 cpu_context(cpu, mm) & ASID_MASK, start, end);
91 #endif
92 local_irq_save(flags);
93 size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
94 if (size <= current_cpu_data.tlbsize) {
95 int oldpid = read_c0_entryhi() & ASID_MASK;
96 int newpid = cpu_context(cpu, mm) & ASID_MASK;
97
98 start &= PAGE_MASK;
99 end += PAGE_SIZE - 1;
100 end &= PAGE_MASK;
101 while (start < end) {
102 int idx;
103
104 write_c0_entryhi(start | newpid);
105 start += PAGE_SIZE; /* BARRIER */
106 tlb_probe();
107 idx = read_c0_index();
108 write_c0_entrylo0(0);
109 write_c0_entryhi(KSEG0);
110 if (idx < 0) /* BARRIER */
111 continue;
112 tlb_write_indexed();
113 }
114 write_c0_entryhi(oldpid);
115 } else {
116 drop_mmu_context(mm, cpu);
117 }
118 local_irq_restore(flags);
119 }
120 }
121
local_flush_tlb_kernel_range(unsigned long start,unsigned long end)122 void local_flush_tlb_kernel_range(unsigned long start, unsigned long end)
123 {
124 unsigned long size, flags;
125
126 #ifdef DEBUG_TLB
127 printk("[tlbrange<%lu,0x%08lx,0x%08lx>]", start, end);
128 #endif
129 local_irq_save(flags);
130 size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
131 if (size <= current_cpu_data.tlbsize) {
132 int pid = read_c0_entryhi();
133
134 start &= PAGE_MASK;
135 end += PAGE_SIZE - 1;
136 end &= PAGE_MASK;
137
138 while (start < end) {
139 int idx;
140
141 write_c0_entryhi(start);
142 start += PAGE_SIZE; /* BARRIER */
143 tlb_probe();
144 idx = read_c0_index();
145 write_c0_entrylo0(0);
146 write_c0_entryhi(KSEG0);
147 if (idx < 0) /* BARRIER */
148 continue;
149 tlb_write_indexed();
150 }
151 write_c0_entryhi(pid);
152 } else {
153 local_flush_tlb_all();
154 }
155 local_irq_restore(flags);
156 }
157
local_flush_tlb_page(struct vm_area_struct * vma,unsigned long page)158 void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
159 {
160 int cpu = smp_processor_id();
161
162 if (!vma || cpu_context(cpu, vma->vm_mm) != 0) {
163 unsigned long flags;
164 int oldpid, newpid, idx;
165
166 #ifdef DEBUG_TLB
167 printk("[tlbpage<%lu,0x%08lx>]", cpu_context(cpu, vma->vm_mm), page);
168 #endif
169 newpid = cpu_context(cpu, vma->vm_mm) & ASID_MASK;
170 page &= PAGE_MASK;
171 local_irq_save(flags);
172 oldpid = read_c0_entryhi() & ASID_MASK;
173 write_c0_entryhi(page | newpid);
174 BARRIER;
175 tlb_probe();
176 idx = read_c0_index();
177 write_c0_entrylo0(0);
178 write_c0_entryhi(KSEG0);
179 if (idx < 0) /* BARRIER */
180 goto finish;
181 tlb_write_indexed();
182
183 finish:
184 write_c0_entryhi(oldpid);
185 local_irq_restore(flags);
186 }
187 }
188
__update_tlb(struct vm_area_struct * vma,unsigned long address,pte_t pte)189 void __update_tlb(struct vm_area_struct *vma, unsigned long address, pte_t pte)
190 {
191 unsigned long flags;
192 int idx, pid;
193
194 /*
195 * Handle debugger faulting in for debugee.
196 */
197 if (current->active_mm != vma->vm_mm)
198 return;
199
200 pid = read_c0_entryhi() & ASID_MASK;
201
202 #ifdef DEBUG_TLB
203 if ((pid != (cpu_context(cpu, vma->vm_mm) & ASID_MASK)) || (cpu_context(cpu, vma->vm_mm) == 0)) {
204 printk("update_mmu_cache: Wheee, bogus tlbpid mmpid=%lu tlbpid=%d\n",
205 (cpu_context(cpu, vma->vm_mm)), pid);
206 }
207 #endif
208
209 local_irq_save(flags);
210 address &= PAGE_MASK;
211 write_c0_entryhi(address | pid);
212 BARRIER;
213 tlb_probe();
214 idx = read_c0_index();
215 write_c0_entrylo0(pte_val(pte));
216 write_c0_entryhi(address | pid);
217 if (idx < 0) { /* BARRIER */
218 tlb_write_random();
219 } else {
220 tlb_write_indexed();
221 }
222 write_c0_entryhi(pid);
223 local_irq_restore(flags);
224 }
225
add_wired_entry(unsigned long entrylo0,unsigned long entrylo1,unsigned long entryhi,unsigned long pagemask)226 void __init add_wired_entry(unsigned long entrylo0, unsigned long entrylo1,
227 unsigned long entryhi, unsigned long pagemask)
228 {
229 unsigned long flags;
230 unsigned long old_ctx;
231 static unsigned long wired = 0;
232
233 if (r3k_have_wired_reg) { /* TX39XX */
234 unsigned long old_pagemask;
235 unsigned long w;
236
237 #ifdef DEBUG_TLB
238 printk("[tlbwired<entry lo0 %8x, hi %8x\n, pagemask %8x>]\n",
239 entrylo0, entryhi, pagemask);
240 #endif
241
242 local_irq_save(flags);
243 /* Save old context and create impossible VPN2 value */
244 old_ctx = read_c0_entryhi() & ASID_MASK;
245 old_pagemask = read_c0_pagemask();
246 w = read_c0_wired();
247 write_c0_wired(w + 1);
248 write_c0_index(w << 8);
249 write_c0_pagemask(pagemask);
250 write_c0_entryhi(entryhi);
251 write_c0_entrylo0(entrylo0);
252 BARRIER;
253 tlb_write_indexed();
254
255 write_c0_entryhi(old_ctx);
256 write_c0_pagemask(old_pagemask);
257 local_flush_tlb_all();
258 local_irq_restore(flags);
259
260 } else if (wired < 8) {
261 #ifdef DEBUG_TLB
262 printk("[tlbwired<entry lo0 %8x, hi %8x\n>]\n",
263 entrylo0, entryhi);
264 #endif
265
266 local_irq_save(flags);
267 old_ctx = read_c0_entryhi() & ASID_MASK;
268 write_c0_entrylo0(entrylo0);
269 write_c0_entryhi(entryhi);
270 write_c0_index(wired);
271 wired++; /* BARRIER */
272 tlb_write_indexed();
273 write_c0_entryhi(old_ctx);
274 local_flush_tlb_all();
275 local_irq_restore(flags);
276 }
277 }
278
tlb_init(void)279 void __cpuinit tlb_init(void)
280 {
281 local_flush_tlb_all();
282
283 build_tlb_refill_handler();
284 }
285