summaryrefslogtreecommitdiffstats
path: root/arch/mips/mm/tlb-r3k.c
blob: 2b75b8f880ed1f50df9429d758d2b4d5cf624cd2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
/*
 * r2300.c: R2000 and R3000 specific mmu/cache code.
 *
 * Copyright (C) 1996 David S. Miller (davem@davemloft.net)
 *
 * with a lot of changes to make this thing work for R3000s
 * Tx39XX R4k style caches added. HK
 * Copyright (C) 1998, 1999, 2000 Harald Koerfgen
 * Copyright (C) 1998 Gleb Raiko & Vladimir Roganov
 * Copyright (C) 2002  Ralf Baechle
 * Copyright (C) 2002  Maciej W. Rozycki
 */
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <linux/mm.h>

#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/mmu_context.h>
#include <asm/tlbmisc.h>
#include <asm/isadep.h>
#include <asm/io.h>
#include <asm/bootinfo.h>
#include <asm/cpu.h>

#undef DEBUG_TLB

extern void build_tlb_refill_handler(void);

/* CP0 hazard avoidance. */
#define BARRIER				\
	__asm__ __volatile__(		\
		".set	push\n\t"	\
		".set	noreorder\n\t"	\
		"nop\n\t"		\
		".set	pop\n\t")

static int r3k_have_wired_reg;			/* Should be in cpu_data? */

/* TLB operations. */
static void local_flush_tlb_from(int entry)
{
	unsigned long old_ctx;

	old_ctx = read_c0_entryhi() & ASID_MASK;
	write_c0_entrylo0(0);
	while (entry < current_cpu_data.tlbsize) {
		write_c0_index(entry << 8);
		write_c0_entryhi((entry | 0x80000) << 12);
		entry++;				/* BARRIER */
		tlb_write_indexed();
	}
	write_c0_entryhi(old_ctx);
}

void local_flush_tlb_all(void)
{
	unsigned long flags;

#ifdef DEBUG_TLB
	printk("[tlball]");
#endif
	local_irq_save(flags);
	local_flush_tlb_from(r3k_have_wired_reg ? read_c0_wired() : 8);
	local_irq_restore(flags);
}

void local_flush_tlb_mm(struct mm_struct *mm)
{
	int cpu = smp_processor_id();

	if (cpu_context(cpu, mm) != 0) {
#ifdef DEBUG_TLB
		printk("[tlbmm<%lu>]", (unsigned long)cpu_context(cpu, mm));
#endif
		drop_mmu_context(mm, cpu);
	}
}

void local_flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
			   unsigned long end)
{
	struct mm_struct *mm = vma->vm_mm;
	int cpu = smp_processor_id();

	if (cpu_context(cpu, mm) != 0) {
		unsigned long size, flags;

#ifdef DEBUG_TLB
		printk("[tlbrange<%lu,0x%08lx,0x%08lx>]",
			cpu_context(cpu, mm) & ASID_MASK, start, end);
#endif
		local_irq_save(flags);
		size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
		if (size <= current_cpu_data.tlbsize) {
			int oldpid = read_c0_entryhi() & ASID_MASK;
			int newpid = cpu_context(cpu, mm) & ASID_MASK;

			start &= PAGE_MASK;
			end += PAGE_SIZE - 1;
			end &= PAGE_MASK;
			while (start < end) {
				int idx;

				write_c0_entryhi(start | newpid);
				start += PAGE_SIZE;	/* BARRIER */
				tlb_probe();
				idx = read_c0_index();
				write_c0_entrylo0(0);
				write_c0_entryhi(KSEG0);
				if (idx < 0)		/* BARRIER */
					continue;
				tlb_write_indexed();
			}
			write_c0_entryhi(oldpid);
		} else {
			drop_mmu_context(mm, cpu);
		}
		local_irq_restore(flags);
	}
}

void local_flush_tlb_kernel_range(unsigned long start, unsigned long end)
{
	unsigned long size, flags;

#ifdef DEBUG_TLB
	printk("[tlbrange<%lu,0x%08lx,0x%08lx>]", start, end);
#endif
	local_irq_save(flags);
	size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
	if (size <= current_cpu_data.tlbsize) {
		int pid = read_c0_entryhi();

		start &= PAGE_MASK;
		end += PAGE_SIZE - 1;
		end &= PAGE_MASK;

		while (start < end) {
			int idx;

			write_c0_entryhi(start);
			start += PAGE_SIZE;		/* BARRIER */
			tlb_probe();
			idx = read_c0_index();
			write_c0_entrylo0(0);
			write_c0_entryhi(KSEG0);
			if (idx < 0)			/* BARRIER */
				continue;
			tlb_write_indexed();
		}
		write_c0_entryhi(pid);
	} else {
		local_flush_tlb_all();
	}
	local_irq_restore(flags);
}

void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
{
	int cpu = smp_processor_id();

	if (cpu_context(cpu, vma->vm_mm) != 0) {
		unsigned long flags;
		int oldpid, newpid, idx;

#ifdef DEBUG_TLB
		printk("[tlbpage<%lu,0x%08lx>]", cpu_context(cpu, vma->vm_mm), page);
#endif
		newpid = cpu_context(cpu, vma->vm_mm) & ASID_MASK;
		page &= PAGE_MASK;
		local_irq_save(flags);
		oldpid = read_c0_entryhi() & ASID_MASK;
		write_c0_entryhi(page | newpid);
		BARRIER;
		tlb_probe();
		idx = read_c0_index();
		write_c0_entrylo0(0);
		write_c0_entryhi(KSEG0);
		if (idx < 0)				/* BARRIER */
			goto finish;
		tlb_write_indexed();

finish:
		write_c0_entryhi(oldpid);
		local_irq_restore(flags);
	}
}

void __update_tlb(struct vm_area_struct *vma, unsigned long address, pte_t pte)
{
	unsigned long flags;
	int idx, pid;

	/*
	 * Handle debugger faulting in for debugee.
	 */
	if (current->active_mm != vma->vm_mm)
		return;

	pid = read_c0_entryhi() & ASID_MASK;

#ifdef DEBUG_TLB
	if ((pid != (cpu_context(cpu, vma->vm_mm) & ASID_MASK)) || (cpu_context(cpu, vma->vm_mm) == 0)) {
		printk("update_mmu_cache: Wheee, bogus tlbpid mmpid=%lu tlbpid=%d\n",
		       (cpu_context(cpu, vma->vm_mm)), pid);
	}
#endif

	local_irq_save(flags);
	address &= PAGE_MASK;
	write_c0_entryhi(address | pid);
	BARRIER;
	tlb_probe();
	idx = read_c0_index();
	write_c0_entrylo0(pte_val(pte));
	write_c0_entryhi(address | pid);
	if (idx < 0) {					/* BARRIER */
		tlb_write_random();
	} else {
		tlb_write_indexed();
	}
	write_c0_entryhi(pid);
	local_irq_restore(flags);
}

void add_wired_entry(unsigned long entrylo0, unsigned long entrylo1,
		     unsigned long entryhi, unsigned long pagemask)
{
	unsigned long flags;
	unsigned long old_ctx;
	static unsigned long wired = 0;

	if (r3k_have_wired_reg) {			/* TX39XX */
		unsigned long old_pagemask;
		unsigned long w;

#ifdef DEBUG_TLB
		printk("[tlbwired<entry lo0 %8x, hi %8x\n, pagemask %8x>]\n",
		       entrylo0, entryhi, pagemask);
#endif

		local_irq_save(flags);
		/* Save old context and create impossible VPN2 value */
		old_ctx = read_c0_entryhi() & ASID_MASK;
		old_pagemask = read_c0_pagemask();
		w = read_c0_wired();
		write_c0_wired(w + 1);
		write_c0_index(w << 8);
		write_c0_pagemask(pagemask);
		write_c0_entryhi(entryhi);
		write_c0_entrylo0(entrylo0);
		BARRIER;
		tlb_write_indexed();

		write_c0_entryhi(old_ctx);
		write_c0_pagemask(old_pagemask);
		local_flush_tlb_all();
		local_irq_restore(flags);

	} else if (wired < 8) {
#ifdef DEBUG_TLB
		printk("[tlbwired<entry lo0 %8x, hi %8x\n>]\n",
		       entrylo0, entryhi);
#endif

		local_irq_save(flags);
		old_ctx = read_c0_entryhi() & ASID_MASK;
		write_c0_entrylo0(entrylo0);
		write_c0_entryhi(entryhi);
		write_c0_index(wired);
		wired++;				/* BARRIER */
		tlb_write_indexed();
		write_c0_entryhi(old_ctx);
		local_flush_tlb_all();
		local_irq_restore(flags);
	}
}

void tlb_init(void)
{
	switch (current_cpu_type()) {
	case CPU_TX3922:
	case CPU_TX3927:
		r3k_have_wired_reg = 1;
		write_c0_wired(0);		/* Set to 8 on reset... */
		break;
	}
	local_flush_tlb_from(0);
	build_tlb_refill_handler();
}