summaryrefslogtreecommitdiff
path: root/arch/powerpc/mm/44x_mmu.c
blob: f60e006d90c3520c41905b2140fd522707214921 (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
/*
 * Modifications by Matt Porter (mporter@mvista.com) to support
 * PPC44x Book E processors.
 *
 * This file contains the routines for initializing the MMU
 * on the 4xx series of chips.
 *  -- paulus
 *
 *  Derived from arch/ppc/mm/init.c:
 *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
 *
 *  Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
 *  and Cort Dougan (PReP) (cort@cs.nmt.edu)
 *    Copyright (C) 1996 Paul Mackerras
 *
 *  Derived from "arch/i386/mm/init.c"
 *    Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License
 *  as published by the Free Software Foundation; either version
 *  2 of the License, or (at your option) any later version.
 *
 */

#include <linux/init.h>
#include <linux/memblock.h>

#include <asm/mmu.h>
#include <asm/system.h>
#include <asm/page.h>
#include <asm/cacheflush.h>

#include "mmu_decl.h"

/* Used by the 44x TLB replacement exception handler.
 * Just needed it declared someplace.
 */
unsigned int tlb_44x_index; /* = 0 */
unsigned int tlb_44x_hwater = PPC44x_TLB_SIZE - 1 - PPC44x_EARLY_TLBS;
int icache_44x_need_flush;

unsigned long tlb_47x_boltmap[1024/8];

static void __cpuinit ppc44x_update_tlb_hwater(void)
{
	extern unsigned int tlb_44x_patch_hwater_D[];
	extern unsigned int tlb_44x_patch_hwater_I[];

	/* The TLB miss handlers hard codes the watermark in a cmpli
	 * instruction to improve performances rather than loading it
	 * from the global variable. Thus, we patch the instructions
	 * in the 2 TLB miss handlers when updating the value
	 */
	tlb_44x_patch_hwater_D[0] = (tlb_44x_patch_hwater_D[0] & 0xffff0000) |
		tlb_44x_hwater;
	flush_icache_range((unsigned long)&tlb_44x_patch_hwater_D[0],
			   (unsigned long)&tlb_44x_patch_hwater_D[1]);
	tlb_44x_patch_hwater_I[0] = (tlb_44x_patch_hwater_I[0] & 0xffff0000) |
		tlb_44x_hwater;
	flush_icache_range((unsigned long)&tlb_44x_patch_hwater_I[0],
			   (unsigned long)&tlb_44x_patch_hwater_I[1]);
}

/*
 * "Pins" a 256MB TLB entry in AS0 for kernel lowmem for 44x type MMU
 */
static void __init ppc44x_pin_tlb(unsigned int virt, unsigned int phys)
{
	unsigned int entry = tlb_44x_hwater--;

	ppc44x_update_tlb_hwater();

	mtspr(SPRN_MMUCR, 0);

	__asm__ __volatile__(
		"tlbwe	%2,%3,%4\n"
		"tlbwe	%1,%3,%5\n"
		"tlbwe	%0,%3,%6\n"
	:
#ifdef CONFIG_PPC47x
	: "r" (PPC47x_TLB2_S_RWX),
#else
	: "r" (PPC44x_TLB_SW | PPC44x_TLB_SR | PPC44x_TLB_SX | PPC44x_TLB_G),
#endif
	  "r" (phys),
	  "r" (virt | PPC44x_TLB_VALID | PPC44x_TLB_256M),
	  "r" (entry),
	  "i" (PPC44x_TLB_PAGEID),
	  "i" (PPC44x_TLB_XLAT),
	  "i" (PPC44x_TLB_ATTRIB));
}

static int __init ppc47x_find_free_bolted(void)
{
	unsigned int mmube0 = mfspr(SPRN_MMUBE0);
	unsigned int mmube1 = mfspr(SPRN_MMUBE1);

	if (!(mmube0 & MMUBE0_VBE0))
		return 0;
	if (!(mmube0 & MMUBE0_VBE1))
		return 1;
	if (!(mmube0 & MMUBE0_VBE2))
		return 2;
	if (!(mmube1 & MMUBE1_VBE3))
		return 3;
	if (!(mmube1 & MMUBE1_VBE4))
		return 4;
	if (!(mmube1 & MMUBE1_VBE5))
		return 5;
	return -1;
}

static void __init ppc47x_update_boltmap(void)
{
	unsigned int mmube0 = mfspr(SPRN_MMUBE0);
	unsigned int mmube1 = mfspr(SPRN_MMUBE1);

	if (mmube0 & MMUBE0_VBE0)
		__set_bit((mmube0 >> MMUBE0_IBE0_SHIFT) & 0xff,
			  tlb_47x_boltmap);
	if (mmube0 & MMUBE0_VBE1)
		__set_bit((mmube0 >> MMUBE0_IBE1_SHIFT) & 0xff,
			  tlb_47x_boltmap);
	if (mmube0 & MMUBE0_VBE2)
		__set_bit((mmube0 >> MMUBE0_IBE2_SHIFT) & 0xff,
			  tlb_47x_boltmap);
	if (mmube1 & MMUBE1_VBE3)
		__set_bit((mmube1 >> MMUBE1_IBE3_SHIFT) & 0xff,
			  tlb_47x_boltmap);
	if (mmube1 & MMUBE1_VBE4)
		__set_bit((mmube1 >> MMUBE1_IBE4_SHIFT) & 0xff,
			  tlb_47x_boltmap);
	if (mmube1 & MMUBE1_VBE5)
		__set_bit((mmube1 >> MMUBE1_IBE5_SHIFT) & 0xff,
			  tlb_47x_boltmap);
}

/*
 * "Pins" a 256MB TLB entry in AS0 for kernel lowmem for 47x type MMU
 */
static void __cpuinit ppc47x_pin_tlb(unsigned int virt, unsigned int phys)
{
	unsigned int rA;
	int bolted;

	/* Base rA is HW way select, way 0, bolted bit set */
	rA = 0x88000000;

	/* Look for a bolted entry slot */
	bolted = ppc47x_find_free_bolted();
	BUG_ON(bolted < 0);

	/* Insert bolted slot number */
	rA |= bolted << 24;

	pr_debug("256M TLB entry for 0x%08x->0x%08x in bolt slot %d\n",
		 virt, phys, bolted);

	mtspr(SPRN_MMUCR, 0);

	__asm__ __volatile__(
		"tlbwe	%2,%3,0\n"
		"tlbwe	%1,%3,1\n"
		"tlbwe	%0,%3,2\n"
		:
		: "r" (PPC47x_TLB2_SW | PPC47x_TLB2_SR |
		       PPC47x_TLB2_SX
#ifdef CONFIG_SMP
		       | PPC47x_TLB2_M
#endif
		       ),
		  "r" (phys),
		  "r" (virt | PPC47x_TLB0_VALID | PPC47x_TLB0_256M),
		  "r" (rA));
}

void __init MMU_init_hw(void)
{
	/* This is not useful on 47x but won't hurt either */
	ppc44x_update_tlb_hwater();

	flush_instruction_cache();
}

unsigned long __init mmu_mapin_ram(unsigned long top)
{
	unsigned long addr;
	unsigned long memstart = memstart_addr & ~(PPC_PIN_SIZE - 1);

	/* Pin in enough TLBs to cover any lowmem not covered by the
	 * initial 256M mapping established in head_44x.S */
	for (addr = memstart + PPC_PIN_SIZE; addr < lowmem_end_addr;
	     addr += PPC_PIN_SIZE) {
		if (mmu_has_feature(MMU_FTR_TYPE_47x))
			ppc47x_pin_tlb(addr + PAGE_OFFSET, addr);
		else
			ppc44x_pin_tlb(addr + PAGE_OFFSET, addr);
	}
	if (mmu_has_feature(MMU_FTR_TYPE_47x)) {
		ppc47x_update_boltmap();

#ifdef DEBUG
		{
			int i;

			printk(KERN_DEBUG "bolted entries: ");
			for (i = 0; i < 255; i++) {
				if (test_bit(i, tlb_47x_boltmap))
					printk("%d ", i);
			}
			printk("\n");
		}
#endif /* DEBUG */
	}
	return total_lowmem;
}

void setup_initial_memory_limit(phys_addr_t first_memblock_base,
				phys_addr_t first_memblock_size)
{
	u64 size;

#ifndef CONFIG_RELOCATABLE
	/* We don't currently support the first MEMBLOCK not mapping 0
	 * physical on those processors
	 */
	BUG_ON(first_memblock_base != 0);
#endif

	/* 44x has a 256M TLB entry pinned at boot */
	size = (min_t(u64, first_memblock_size, PPC_PIN_SIZE));
	memblock_set_current_limit(first_memblock_base + size);
}

#ifdef CONFIG_SMP
void __cpuinit mmu_init_secondary(int cpu)
{
	unsigned long addr;
	unsigned long memstart = memstart_addr & ~(PPC_PIN_SIZE - 1);

	/* Pin in enough TLBs to cover any lowmem not covered by the
	 * initial 256M mapping established in head_44x.S
	 *
	 * WARNING: This is called with only the first 256M of the
	 * linear mapping in the TLB and we can't take faults yet
	 * so beware of what this code uses. It runs off a temporary
	 * stack. current (r2) isn't initialized, smp_processor_id()
	 * will not work, current thread info isn't accessible, ...
	 */
	for (addr = memstart + PPC_PIN_SIZE; addr < lowmem_end_addr;
	     addr += PPC_PIN_SIZE) {
		if (mmu_has_feature(MMU_FTR_TYPE_47x))
			ppc47x_pin_tlb(addr + PAGE_OFFSET, addr);
		else
			ppc44x_pin_tlb(addr + PAGE_OFFSET, addr);
	}
}
#endif /* CONFIG_SMP */