summaryrefslogtreecommitdiffstats
path: root/cpu/ppc4xx/tlb.c
blob: 50344a491c1603eb1695aa4ff60659517c7e5fa6 (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
/*
 * (C) Copyright 2007
 * Stefan Roese, DENX Software Engineering, sr@denx.de.
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 */

#include <common.h>

#if defined(CONFIG_440)

#include <ppc4xx.h>
#include <ppc440.h>
#include <asm/io.h>
#include <asm/mmu.h>

typedef struct region {
	unsigned long base;
	unsigned long size;
	unsigned long tlb_word2_i_value;
} region_t;

static int add_tlb_entry(unsigned long base_addr,
			 unsigned long tlb_word0_size_value,
			 unsigned long tlb_word2_i_value)
{
	int i;
	unsigned long tlb_word0_value;
	unsigned long tlb_word1_value;
	unsigned long tlb_word2_value;

	/* First, find the index of a TLB entry not being used */
	for (i=0; i<PPC4XX_TLB_SIZE; i++) {
		tlb_word0_value = mftlb1(i);
		if ((tlb_word0_value & TLB_WORD0_V_MASK) == TLB_WORD0_V_DISABLE)
			break;
	}
	if (i >= PPC4XX_TLB_SIZE)
		return -1;

	/* Second, create the TLB entry */
	tlb_word0_value = TLB_WORD0_EPN_ENCODE(base_addr) | TLB_WORD0_V_ENABLE |
		TLB_WORD0_TS_0 | tlb_word0_size_value;
	tlb_word1_value = TLB_WORD1_RPN_ENCODE(base_addr) | TLB_WORD1_ERPN_ENCODE(0);
	tlb_word2_value = TLB_WORD2_U0_DISABLE | TLB_WORD2_U1_DISABLE |
		TLB_WORD2_U2_DISABLE | TLB_WORD2_U3_DISABLE |
		TLB_WORD2_W_DISABLE | tlb_word2_i_value |
		TLB_WORD2_M_DISABLE | TLB_WORD2_G_DISABLE |
		TLB_WORD2_E_DISABLE | TLB_WORD2_UX_ENABLE |
		TLB_WORD2_UW_ENABLE | TLB_WORD2_UR_ENABLE |
		TLB_WORD2_SX_ENABLE | TLB_WORD2_SW_ENABLE |
		TLB_WORD2_SR_ENABLE;

	/* Wait for all memory accesses to complete */
	sync();

	/* Third, add the TLB entries */
	mttlb1(i, tlb_word0_value);
	mttlb2(i, tlb_word1_value);
	mttlb3(i, tlb_word2_value);

	/* Execute an ISYNC instruction so that the new TLB entry takes effect */
	asm("isync");

	return 0;
}

static void program_tlb_addr(unsigned long base_addr, unsigned long mem_size,
			     unsigned long tlb_word2_i_value)
{
	int rc;
	int tlb_i;

	tlb_i = tlb_word2_i_value;
	while (mem_size != 0) {
		rc = 0;
		/* Add the TLB entries in to map the region. */
		if (((base_addr & TLB_256MB_ALIGN_MASK) == base_addr) &&
		    (mem_size >= TLB_256MB_SIZE)) {
			/* Add a 256MB TLB entry */
			if ((rc = add_tlb_entry(base_addr, TLB_WORD0_SIZE_256MB, tlb_i)) == 0) {
				mem_size -= TLB_256MB_SIZE;
				base_addr += TLB_256MB_SIZE;
			}
		} else if (((base_addr & TLB_16MB_ALIGN_MASK) == base_addr) &&
			   (mem_size >= TLB_16MB_SIZE)) {
			/* Add a 16MB TLB entry */
			if ((rc = add_tlb_entry(base_addr, TLB_WORD0_SIZE_16MB, tlb_i)) == 0) {
				mem_size -= TLB_16MB_SIZE;
				base_addr += TLB_16MB_SIZE;
			}
		} else if (((base_addr & TLB_1MB_ALIGN_MASK) == base_addr) &&
			   (mem_size >= TLB_1MB_SIZE)) {
			/* Add a 1MB TLB entry */
			if ((rc = add_tlb_entry(base_addr, TLB_WORD0_SIZE_1MB, tlb_i)) == 0) {
				mem_size -= TLB_1MB_SIZE;
				base_addr += TLB_1MB_SIZE;
			}
		} else if (((base_addr & TLB_256KB_ALIGN_MASK) == base_addr) &&
			   (mem_size >= TLB_256KB_SIZE)) {
			/* Add a 256KB TLB entry */
			if ((rc = add_tlb_entry(base_addr, TLB_WORD0_SIZE_256KB, tlb_i)) == 0) {
				mem_size -= TLB_256KB_SIZE;
				base_addr += TLB_256KB_SIZE;
			}
		} else if (((base_addr & TLB_64KB_ALIGN_MASK) == base_addr) &&
			   (mem_size >= TLB_64KB_SIZE)) {
			/* Add a 64KB TLB entry */
			if ((rc = add_tlb_entry(base_addr, TLB_WORD0_SIZE_64KB, tlb_i)) == 0) {
				mem_size -= TLB_64KB_SIZE;
				base_addr += TLB_64KB_SIZE;
			}
		} else if (((base_addr & TLB_16KB_ALIGN_MASK) == base_addr) &&
			   (mem_size >= TLB_16KB_SIZE)) {
			/* Add a 16KB TLB entry */
			if ((rc = add_tlb_entry(base_addr, TLB_WORD0_SIZE_16KB, tlb_i)) == 0) {
				mem_size -= TLB_16KB_SIZE;
				base_addr += TLB_16KB_SIZE;
			}
		} else if (((base_addr & TLB_4KB_ALIGN_MASK) == base_addr) &&
			   (mem_size >= TLB_4KB_SIZE)) {
			/* Add a 4KB TLB entry */
			if ((rc = add_tlb_entry(base_addr, TLB_WORD0_SIZE_4KB, tlb_i)) == 0) {
				mem_size -= TLB_4KB_SIZE;
				base_addr += TLB_4KB_SIZE;
			}
		} else if (((base_addr & TLB_1KB_ALIGN_MASK) == base_addr) &&
			   (mem_size >= TLB_1KB_SIZE)) {
			/* Add a 1KB TLB entry */
			if ((rc = add_tlb_entry(base_addr, TLB_WORD0_SIZE_1KB, tlb_i)) == 0) {
				mem_size -= TLB_1KB_SIZE;
				base_addr += TLB_1KB_SIZE;
			}
		} else {
			printf("ERROR: no TLB size exists for the base address 0x%0X.\n",
				base_addr);
		}

		if (rc != 0)
			printf("ERROR: no TLB entries available for the base addr 0x%0X.\n",
				base_addr);
	}

	return;
}

/*
 * Program one (or multiple) TLB entries for one memory region
 *
 * Common usage for boards with SDRAM DIMM modules to dynamically
 * configure the TLB's for the SDRAM
 */
void program_tlb(u32 start, u32 size, u32 tlb_word2_i_value)
{
	region_t region_array;

	region_array.base = start;
	region_array.size = size;
	region_array.tlb_word2_i_value = tlb_word2_i_value;	/* en-/disable cache */

	/* Call the routine to add in the tlb entries for the memory regions */
	program_tlb_addr(region_array.base, region_array.size,
			 region_array.tlb_word2_i_value);

	return;
}

#endif /* CONFIG_440 */