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-rw-r--r--arch/sh/mm/pmb.c269
1 files changed, 269 insertions, 0 deletions
diff --git a/arch/sh/mm/pmb.c b/arch/sh/mm/pmb.c
new file mode 100644
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+++ b/arch/sh/mm/pmb.c
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1/*
2 * arch/sh/mm/pmb.c
3 *
4 * Privileged Space Mapping Buffer (PMB) Support.
5 *
6 * Copyright (C) 2005 Paul Mundt
7 *
8 * P1/P2 Section mapping definitions from map32.h, which was:
9 *
10 * Copyright 2003 (c) Lineo Solutions,Inc.
11 *
12 * This file is subject to the terms and conditions of the GNU General Public
13 * License. See the file "COPYING" in the main directory of this archive
14 * for more details.
15 */
16#include <linux/init.h>
17#include <linux/kernel.h>
18#include <linux/module.h>
19#include <linux/slab.h>
20#include <linux/bitops.h>
21#include <linux/debugfs.h>
22#include <linux/fs.h>
23#include <linux/seq_file.h>
24#include <linux/err.h>
25#include <asm/system.h>
26#include <asm/uaccess.h>
27#include <asm/mmu.h>
28#include <asm/io.h>
29
30#define NR_PMB_ENTRIES 16
31
32static kmem_cache_t *pmb_cache;
33static unsigned long pmb_map;
34
35static struct pmb_entry pmb_init_map[] = {
36 /* vpn ppn flags (ub/sz/c/wt) */
37
38 /* P1 Section Mappings */
39 { 0x80000000, 0x00000000, PMB_SZ_64M | PMB_C, },
40 { 0x84000000, 0x04000000, PMB_SZ_64M | PMB_C, },
41 { 0x88000000, 0x08000000, PMB_SZ_128M | PMB_C, },
42 { 0x90000000, 0x10000000, PMB_SZ_64M | PMB_C, },
43 { 0x94000000, 0x14000000, PMB_SZ_64M | PMB_C, },
44 { 0x98000000, 0x18000000, PMB_SZ_64M | PMB_C, },
45
46 /* P2 Section Mappings */
47 { 0xa0000000, 0x00000000, PMB_UB | PMB_SZ_64M | PMB_WT, },
48 { 0xa4000000, 0x04000000, PMB_UB | PMB_SZ_64M | PMB_WT, },
49 { 0xa8000000, 0x08000000, PMB_UB | PMB_SZ_128M | PMB_WT, },
50 { 0xb0000000, 0x10000000, PMB_UB | PMB_SZ_64M | PMB_WT, },
51 { 0xb4000000, 0x14000000, PMB_UB | PMB_SZ_64M | PMB_WT, },
52 { 0xb8000000, 0x18000000, PMB_UB | PMB_SZ_64M | PMB_WT, },
53};
54
55static inline unsigned long mk_pmb_entry(unsigned int entry)
56{
57 return (entry & PMB_E_MASK) << PMB_E_SHIFT;
58}
59
60static inline unsigned long mk_pmb_addr(unsigned int entry)
61{
62 return mk_pmb_entry(entry) | PMB_ADDR;
63}
64
65static inline unsigned long mk_pmb_data(unsigned int entry)
66{
67 return mk_pmb_entry(entry) | PMB_DATA;
68}
69
70struct pmb_entry *pmb_alloc(unsigned long vpn, unsigned long ppn,
71 unsigned long flags)
72{
73 struct pmb_entry *pmbe;
74
75 pmbe = kmem_cache_alloc(pmb_cache, GFP_KERNEL);
76 if (!pmbe)
77 return ERR_PTR(-ENOMEM);
78
79 pmbe->vpn = vpn;
80 pmbe->ppn = ppn;
81 pmbe->flags = flags;
82
83 return pmbe;
84}
85
86void pmb_free(struct pmb_entry *pmbe)
87{
88 kmem_cache_free(pmb_cache, pmbe);
89}
90
91/*
92 * Must be in P2 for __set_pmb_entry()
93 */
94int __set_pmb_entry(unsigned long vpn, unsigned long ppn,
95 unsigned long flags, int *entry)
96{
97 unsigned int pos = *entry;
98
99 if (unlikely(pos == PMB_NO_ENTRY))
100 pos = find_first_zero_bit(&pmb_map, NR_PMB_ENTRIES);
101
102repeat:
103 if (unlikely(pos > NR_PMB_ENTRIES))
104 return -ENOSPC;
105
106 if (test_and_set_bit(pos, &pmb_map)) {
107 pos = find_first_zero_bit(&pmb_map, NR_PMB_ENTRIES);
108 goto repeat;
109 }
110
111 ctrl_outl(vpn | PMB_V, mk_pmb_addr(pos));
112
113#ifdef CONFIG_SH_WRITETHROUGH
114 /*
115 * When we are in 32-bit address extended mode, CCR.CB becomes
116 * invalid, so care must be taken to manually adjust cacheable
117 * translations.
118 */
119 if (likely(flags & PMB_C))
120 flags |= PMB_WT;
121#endif
122
123 ctrl_outl(ppn | flags | PMB_V, mk_pmb_data(pos));
124
125 *entry = pos;
126
127 return 0;
128}
129
130void set_pmb_entry(struct pmb_entry *pmbe)
131{
132 jump_to_P2();
133 __set_pmb_entry(pmbe->vpn, pmbe->ppn, pmbe->flags, &pmbe->entry);
134 back_to_P1();
135}
136
137void clear_pmb_entry(struct pmb_entry *pmbe)
138{
139 unsigned int entry = pmbe->entry;
140 unsigned long addr;
141
142 /*
143 * Don't allow clearing of wired init entries, P1 or P2 access
144 * without a corresponding mapping in the PMB will lead to reset
145 * by the TLB.
146 */
147 if (unlikely(entry < ARRAY_SIZE(pmb_init_map) ||
148 entry >= NR_PMB_ENTRIES))
149 return;
150
151 jump_to_P2();
152
153 /* Clear V-bit */
154 addr = mk_pmb_addr(entry);
155 ctrl_outl(ctrl_inl(addr) & ~PMB_V, addr);
156
157 addr = mk_pmb_data(entry);
158 ctrl_outl(ctrl_inl(addr) & ~PMB_V, addr);
159
160 back_to_P1();
161
162 clear_bit(entry, &pmb_map);
163}
164
165static void pmb_cache_ctor(void *pmb, kmem_cache_t *cachep, unsigned long flags)
166{
167 memset(pmb, 0, sizeof(struct pmb_entry));
168
169 ((struct pmb_entry *)pmb)->entry = PMB_NO_ENTRY;
170}
171
172static int __init pmb_init(void)
173{
174 unsigned int nr_entries = ARRAY_SIZE(pmb_init_map);
175 unsigned int entry;
176
177 BUG_ON(unlikely(nr_entries >= NR_PMB_ENTRIES));
178
179 pmb_cache = kmem_cache_create("pmb", sizeof(struct pmb_entry),
180 0, 0, pmb_cache_ctor, NULL);
181 BUG_ON(!pmb_cache);
182
183 jump_to_P2();
184
185 /*
186 * Ordering is important, P2 must be mapped in the PMB before we
187 * can set PMB.SE, and P1 must be mapped before we jump back to
188 * P1 space.
189 */
190 for (entry = 0; entry < nr_entries; entry++) {
191 struct pmb_entry *pmbe = pmb_init_map + entry;
192
193 __set_pmb_entry(pmbe->vpn, pmbe->ppn, pmbe->flags, &entry);
194 }
195
196 ctrl_outl(0, PMB_IRMCR);
197
198 /* PMB.SE and UB[7] */
199 ctrl_outl((1 << 31) | (1 << 7), PMB_PASCR);
200
201 back_to_P1();
202
203 return 0;
204}
205
206arch_initcall(pmb_init);
207
208#ifdef CONFIG_DEBUG_FS
209static int pmb_seq_show(struct seq_file *file, void *iter)
210{
211 int i;
212
213 seq_printf(file, "V: Valid, C: Cacheable, WT: Write-Through\n"
214 "CB: Copy-Back, B: Buffered, UB: Unbuffered\n");
215 seq_printf(file, "ety vpn ppn size flags\n");
216
217 for (i = 0; i < NR_PMB_ENTRIES; i++) {
218 unsigned long addr, data;
219 unsigned int size;
220 char *sz_str = NULL;
221
222 addr = ctrl_inl(mk_pmb_addr(i));
223 data = ctrl_inl(mk_pmb_data(i));
224
225 size = data & PMB_SZ_MASK;
226 sz_str = (size == PMB_SZ_16M) ? " 16MB":
227 (size == PMB_SZ_64M) ? " 64MB":
228 (size == PMB_SZ_128M) ? "128MB":
229 "512MB";
230
231 /* 02: V 0x88 0x08 128MB C CB B */
232 seq_printf(file, "%02d: %c 0x%02lx 0x%02lx %s %c %s %s\n",
233 i, ((addr & PMB_V) && (data & PMB_V)) ? 'V' : ' ',
234 (addr >> 24) & 0xff, (data >> 24) & 0xff,
235 sz_str, (data & PMB_C) ? 'C' : ' ',
236 (data & PMB_WT) ? "WT" : "CB",
237 (data & PMB_UB) ? "UB" : " B");
238 }
239
240 return 0;
241}
242
243static int pmb_debugfs_open(struct inode *inode, struct file *file)
244{
245 return single_open(file, pmb_seq_show, NULL);
246}
247
248static struct file_operations pmb_debugfs_fops = {
249 .owner = THIS_MODULE,
250 .open = pmb_debugfs_open,
251 .read = seq_read,
252 .llseek = seq_lseek,
253 .release = seq_release,
254};
255
256static int __init pmb_debugfs_init(void)
257{
258 struct dentry *dentry;
259
260 dentry = debugfs_create_file("pmb", S_IFREG | S_IRUGO,
261 NULL, NULL, &pmb_debugfs_fops);
262 if (IS_ERR(dentry))
263 return PTR_ERR(dentry);
264
265 return 0;
266}
267
268postcore_initcall(pmb_debugfs_init);
269#endif