1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * r2300.c: R2000 and R3000 specific mmu/cache code.
4 *
5 * Copyright (C) 1996 David S. Miller (davem@davemloft.net)
6 *
7 * with a lot of changes to make this thing work for R3000s
8 * Tx39XX R4k style caches added. HK
9 * Copyright (C) 1998, 1999, 2000 Harald Koerfgen
10 * Copyright (C) 1998 Gleb Raiko & Vladimir Roganov
11 * Copyright (C) 2002 Ralf Baechle
12 * Copyright (C) 2002 Maciej W. Rozycki
13 */
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/mmu_context.h>
21 #include <asm/tlbmisc.h>
22 #include <asm/isadep.h>
23 #include <asm/io.h>
24 #include <asm/bootinfo.h>
25 #include <asm/cpu.h>
26
27 #undef DEBUG_TLB
28
29 extern void build_tlb_refill_handler(void);
30
31 /* CP0 hazard avoidance. */
32 #define BARRIER \
33 __asm__ __volatile__( \
34 ".set push\n\t" \
35 ".set noreorder\n\t" \
36 "nop\n\t" \
37 ".set pop\n\t")
38
39 int r3k_have_wired_reg; /* Should be in cpu_data? */
40
41 /* TLB operations. */
local_flush_tlb_from(int entry)42 static void local_flush_tlb_from(int entry)
43 {
44 unsigned long old_ctx;
45
46 old_ctx = read_c0_entryhi() & cpu_asid_mask(¤t_cpu_data);
47 write_c0_entrylo0(0);
48 while (entry < current_cpu_data.tlbsize) {
49 write_c0_index(entry << 8);
50 write_c0_entryhi((entry | 0x80000) << 12);
51 entry++; /* BARRIER */
52 tlb_write_indexed();
53 }
54 write_c0_entryhi(old_ctx);
55 }
56
local_flush_tlb_all(void)57 void local_flush_tlb_all(void)
58 {
59 unsigned long flags;
60
61 #ifdef DEBUG_TLB
62 printk("[tlball]");
63 #endif
64 local_irq_save(flags);
65 local_flush_tlb_from(r3k_have_wired_reg ? read_c0_wired() : 8);
66 local_irq_restore(flags);
67 }
68
local_flush_tlb_range(struct vm_area_struct * vma,unsigned long start,unsigned long end)69 void local_flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
70 unsigned long end)
71 {
72 unsigned long asid_mask = cpu_asid_mask(¤t_cpu_data);
73 struct mm_struct *mm = vma->vm_mm;
74 int cpu = smp_processor_id();
75
76 if (cpu_context(cpu, mm) != 0) {
77 unsigned long size, flags;
78
79 #ifdef DEBUG_TLB
80 printk("[tlbrange<%lu,0x%08lx,0x%08lx>]",
81 cpu_context(cpu, mm) & asid_mask, start, end);
82 #endif
83 local_irq_save(flags);
84 size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
85 if (size <= current_cpu_data.tlbsize) {
86 int oldpid = read_c0_entryhi() & asid_mask;
87 int newpid = cpu_context(cpu, mm) & asid_mask;
88
89 start &= PAGE_MASK;
90 end += PAGE_SIZE - 1;
91 end &= PAGE_MASK;
92 while (start < end) {
93 int idx;
94
95 write_c0_entryhi(start | newpid);
96 start += PAGE_SIZE; /* BARRIER */
97 tlb_probe();
98 idx = read_c0_index();
99 write_c0_entrylo0(0);
100 write_c0_entryhi(KSEG0);
101 if (idx < 0) /* BARRIER */
102 continue;
103 tlb_write_indexed();
104 }
105 write_c0_entryhi(oldpid);
106 } else {
107 drop_mmu_context(mm);
108 }
109 local_irq_restore(flags);
110 }
111 }
112
local_flush_tlb_kernel_range(unsigned long start,unsigned long end)113 void local_flush_tlb_kernel_range(unsigned long start, unsigned long end)
114 {
115 unsigned long size, flags;
116
117 #ifdef DEBUG_TLB
118 printk("[tlbrange<%lu,0x%08lx,0x%08lx>]", start, end);
119 #endif
120 local_irq_save(flags);
121 size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
122 if (size <= current_cpu_data.tlbsize) {
123 int pid = read_c0_entryhi();
124
125 start &= PAGE_MASK;
126 end += PAGE_SIZE - 1;
127 end &= PAGE_MASK;
128
129 while (start < end) {
130 int idx;
131
132 write_c0_entryhi(start);
133 start += PAGE_SIZE; /* BARRIER */
134 tlb_probe();
135 idx = read_c0_index();
136 write_c0_entrylo0(0);
137 write_c0_entryhi(KSEG0);
138 if (idx < 0) /* BARRIER */
139 continue;
140 tlb_write_indexed();
141 }
142 write_c0_entryhi(pid);
143 } else {
144 local_flush_tlb_all();
145 }
146 local_irq_restore(flags);
147 }
148
local_flush_tlb_page(struct vm_area_struct * vma,unsigned long page)149 void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
150 {
151 unsigned long asid_mask = cpu_asid_mask(¤t_cpu_data);
152 int cpu = smp_processor_id();
153
154 if (cpu_context(cpu, vma->vm_mm) != 0) {
155 unsigned long flags;
156 int oldpid, newpid, idx;
157
158 #ifdef DEBUG_TLB
159 printk("[tlbpage<%lu,0x%08lx>]", cpu_context(cpu, vma->vm_mm), page);
160 #endif
161 newpid = cpu_context(cpu, vma->vm_mm) & asid_mask;
162 page &= PAGE_MASK;
163 local_irq_save(flags);
164 oldpid = read_c0_entryhi() & asid_mask;
165 write_c0_entryhi(page | newpid);
166 BARRIER;
167 tlb_probe();
168 idx = read_c0_index();
169 write_c0_entrylo0(0);
170 write_c0_entryhi(KSEG0);
171 if (idx < 0) /* BARRIER */
172 goto finish;
173 tlb_write_indexed();
174
175 finish:
176 write_c0_entryhi(oldpid);
177 local_irq_restore(flags);
178 }
179 }
180
__update_tlb(struct vm_area_struct * vma,unsigned long address,pte_t pte)181 void __update_tlb(struct vm_area_struct *vma, unsigned long address, pte_t pte)
182 {
183 unsigned long asid_mask = cpu_asid_mask(¤t_cpu_data);
184 unsigned long flags;
185 int idx, pid;
186
187 /*
188 * Handle debugger faulting in for debugee.
189 */
190 if (current->active_mm != vma->vm_mm)
191 return;
192
193 pid = read_c0_entryhi() & asid_mask;
194
195 #ifdef DEBUG_TLB
196 if ((pid != (cpu_context(cpu, vma->vm_mm) & asid_mask)) || (cpu_context(cpu, vma->vm_mm) == 0)) {
197 printk("update_mmu_cache: Wheee, bogus tlbpid mmpid=%lu tlbpid=%d\n",
198 (cpu_context(cpu, vma->vm_mm)), pid);
199 }
200 #endif
201
202 local_irq_save(flags);
203 address &= PAGE_MASK;
204 write_c0_entryhi(address | pid);
205 BARRIER;
206 tlb_probe();
207 idx = read_c0_index();
208 write_c0_entrylo0(pte_val(pte));
209 write_c0_entryhi(address | pid);
210 if (idx < 0) { /* BARRIER */
211 tlb_write_random();
212 } else {
213 tlb_write_indexed();
214 }
215 write_c0_entryhi(pid);
216 local_irq_restore(flags);
217 }
218
add_wired_entry(unsigned long entrylo0,unsigned long entrylo1,unsigned long entryhi,unsigned long pagemask)219 void add_wired_entry(unsigned long entrylo0, unsigned long entrylo1,
220 unsigned long entryhi, unsigned long pagemask)
221 {
222 unsigned long asid_mask = cpu_asid_mask(¤t_cpu_data);
223 unsigned long flags;
224 unsigned long old_ctx;
225 static unsigned long wired = 0;
226
227 if (r3k_have_wired_reg) { /* TX39XX */
228 unsigned long old_pagemask;
229 unsigned long w;
230
231 #ifdef DEBUG_TLB
232 printk("[tlbwired<entry lo0 %8x, hi %8x\n, pagemask %8x>]\n",
233 entrylo0, entryhi, pagemask);
234 #endif
235
236 local_irq_save(flags);
237 /* Save old context and create impossible VPN2 value */
238 old_ctx = read_c0_entryhi() & asid_mask;
239 old_pagemask = read_c0_pagemask();
240 w = read_c0_wired();
241 write_c0_wired(w + 1);
242 write_c0_index(w << 8);
243 write_c0_pagemask(pagemask);
244 write_c0_entryhi(entryhi);
245 write_c0_entrylo0(entrylo0);
246 BARRIER;
247 tlb_write_indexed();
248
249 write_c0_entryhi(old_ctx);
250 write_c0_pagemask(old_pagemask);
251 local_flush_tlb_all();
252 local_irq_restore(flags);
253
254 } else if (wired < 8) {
255 #ifdef DEBUG_TLB
256 printk("[tlbwired<entry lo0 %8x, hi %8x\n>]\n",
257 entrylo0, entryhi);
258 #endif
259
260 local_irq_save(flags);
261 old_ctx = read_c0_entryhi() & asid_mask;
262 write_c0_entrylo0(entrylo0);
263 write_c0_entryhi(entryhi);
264 write_c0_index(wired);
265 wired++; /* BARRIER */
266 tlb_write_indexed();
267 write_c0_entryhi(old_ctx);
268 local_flush_tlb_all();
269 local_irq_restore(flags);
270 }
271 }
272
tlb_init(void)273 void tlb_init(void)
274 {
275 switch (current_cpu_type()) {
276 case CPU_TX3922:
277 case CPU_TX3927:
278 r3k_have_wired_reg = 1;
279 write_c0_wired(0); /* Set to 8 on reset... */
280 break;
281 }
282 local_flush_tlb_from(0);
283 build_tlb_refill_handler();
284 }
285