aboutsummaryrefslogtreecommitdiffstats
path: root/arch/mips/mm/tlb-r8k.c
blob: 266a47d65eed06d29ee57745c12fac5959e8afd0 (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
/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 1996 David S. Miller (dm@engr.sgi.com)
 * Copyright (C) 1997, 1998, 1999, 2000 Ralf Baechle ralf@gnu.org
 * Carsten Langgaard, carstenl@mips.com
 * Copyright (C) 2002 MIPS Technologies, Inc.  All rights reserved.
 */
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/mm.h>

#include <asm/cpu.h>
#include <asm/bootinfo.h>
#include <asm/mmu_context.h>
#include <asm/pgtable.h>
#include <asm/system.h>

extern void build_tlb_refill_handler(void);

#define TFP_TLB_SIZE		384
#define TFP_TLB_SET_SHIFT	7

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

void local_flush_tlb_all(void)
{
	unsigned long flags;
	unsigned long old_ctx;
	int entry;

	local_irq_save(flags);
	/* Save old context and create impossible VPN2 value */
	old_ctx = read_c0_entryhi();
	write_c0_entrylo(0);

	for (entry = 0; entry < TFP_TLB_SIZE; entry++) {
		write_c0_tlbset(entry >> TFP_TLB_SET_SHIFT);
		write_c0_vaddr(entry << PAGE_SHIFT);
		write_c0_entryhi(CKSEG0 + (entry << (PAGE_SHIFT + 1)));
		mtc0_tlbw_hazard();
		tlb_write();
	}
	tlbw_use_hazard();
	write_c0_entryhi(old_ctx);
	local_irq_restore(flags);
}

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

	if (cpu_context(cpu, mm) != 0)
		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();
	unsigned long flags;
	int oldpid, newpid, size;

	if (!cpu_context(cpu, mm))
		return;

	size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
	size = (size + 1) >> 1;

	local_irq_save(flags);

	if (size > TFP_TLB_SIZE / 2) {
		drop_mmu_context(mm, cpu);
		goto out_restore;
	}

	oldpid = read_c0_entryhi();
	newpid = cpu_asid(cpu, mm);

	write_c0_entrylo(0);

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

		write_c0_vaddr(start);
		write_c0_entryhi(start);
		start += PAGE_SIZE;
		tlb_probe();
		idx = read_c0_tlbset();
		if (idx < 0)
			continue;

		write_c0_entryhi(CKSEG0 + (idx << (PAGE_SHIFT + 1)));
		tlb_write();
	}
	write_c0_entryhi(oldpid);

out_restore:
	local_irq_restore(flags);
}

/* Usable for KV1 addresses only! */
void local_flush_tlb_kernel_range(unsigned long start, unsigned long end)
{
	unsigned long flags;
	int size;

	size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
	size = (size + 1) >> 1;

	if (size > TFP_TLB_SIZE / 2) {
		local_flush_tlb_all();
		return;
	}

	local_irq_save(flags);

	write_c0_entrylo(0);

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

		write_c0_vaddr(start);
		write_c0_entryhi(start);
		start += PAGE_SIZE;
		tlb_probe();
		idx = read_c0_tlbset();
		if (idx < 0)
			continue;

		write_c0_entryhi(CKSEG0 + (idx << (PAGE_SHIFT + 1)));
		tlb_write();
	}

	local_irq_restore(flags);
}

void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
{
	int cpu = smp_processor_id();
	unsigned long flags;
	int oldpid, newpid;
	signed long idx;

	if (!cpu_context(cpu, vma->vm_mm))
		return;

	newpid = cpu_asid(cpu, vma->vm_mm);
	page &= PAGE_MASK;
	local_irq_save(flags);
	oldpid = read_c0_entryhi();
	write_c0_vaddr(page);
	write_c0_entryhi(newpid);
	tlb_probe();
	idx = read_c0_tlbset();
	if (idx < 0)
		goto finish;

	write_c0_entrylo(0);
	write_c0_entryhi(CKSEG0 + (idx << (PAGE_SHIFT + 1)));
	tlb_write();

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

/*
 * We will need multiple versions of update_mmu_cache(), one that just
 * updates the TLB with the new pte(s), and another which also checks
 * for the R4k "end of page" hardware bug and does the needy.
 */
void __update_tlb(struct vm_area_struct * vma, unsigned long address, pte_t pte)
{
	unsigned long flags;
	pgd_t *pgdp;
	pmd_t *pmdp;
	pte_t *ptep;
	int pid;

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

	pid = read_c0_entryhi() & ASID_MASK;

	local_irq_save(flags);
	address &= PAGE_MASK;
	write_c0_vaddr(address);
	write_c0_entryhi(pid);
	pgdp = pgd_offset(vma->vm_mm, address);
	pmdp = pmd_offset(pgdp, address);
	ptep = pte_offset_map(pmdp, address);
	tlb_probe();

	write_c0_entrylo(pte_val(*ptep++) >> 6);
	tlb_write();

	write_c0_entryhi(pid);
	local_irq_restore(flags);
}

static void __init probe_tlb(unsigned long config)
{
	struct cpuinfo_mips *c = &current_cpu_data;

	c->tlbsize = 3 * 128;		/* 3 sets each 128 entries */
}

void __init tlb_init(void)
{
	unsigned int config = read_c0_config();
	unsigned long status;

	probe_tlb(config);

	status = read_c0_status();
	status &= ~(ST0_UPS | ST0_KPS);
#ifdef CONFIG_PAGE_SIZE_4KB
	status |= (TFP_PAGESIZE_4K << 32) | (TFP_PAGESIZE_4K << 36);
#elif defined(CONFIG_PAGE_SIZE_8KB)
	status |= (TFP_PAGESIZE_8K << 32) | (TFP_PAGESIZE_8K << 36);
#elif defined(CONFIG_PAGE_SIZE_16KB)
	status |= (TFP_PAGESIZE_16K << 32) | (TFP_PAGESIZE_16K << 36);
#elif defined(CONFIG_PAGE_SIZE_64KB)
	status |= (TFP_PAGESIZE_64K << 32) | (TFP_PAGESIZE_64K << 36);
#endif
	write_c0_status(status);

	write_c0_wired(0);

	local_flush_tlb_all();

	build_tlb_refill_handler();
}