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
293
|
/*
* Trapped io support
*
* Copyright (C) 2008 Magnus Damm
*
* Intercept io operations by trapping.
*
* 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.
*/
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/bitops.h>
#include <linux/vmalloc.h>
#include <linux/module.h>
#include <linux/init.h>
#include <asm/system.h>
#include <asm/mmu_context.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#include <asm/io_trapped.h>
#define TRAPPED_PAGES_MAX 16
#ifdef CONFIG_HAS_IOPORT
LIST_HEAD(trapped_io);
EXPORT_SYMBOL_GPL(trapped_io);
#endif
#ifdef CONFIG_HAS_IOMEM
LIST_HEAD(trapped_mem);
EXPORT_SYMBOL_GPL(trapped_mem);
#endif
static DEFINE_SPINLOCK(trapped_lock);
static int trapped_io_disable __read_mostly;
static int __init trapped_io_setup(char *__unused)
{
trapped_io_disable = 1;
return 1;
}
__setup("noiotrap", trapped_io_setup);
int register_trapped_io(struct trapped_io *tiop)
{
struct resource *res;
unsigned long len = 0, flags = 0;
struct page *pages[TRAPPED_PAGES_MAX];
int k, n;
if (unlikely(trapped_io_disable))
return 0;
/* structure must be page aligned */
if ((unsigned long)tiop & (PAGE_SIZE - 1))
goto bad;
for (k = 0; k < tiop->num_resources; k++) {
res = tiop->resource + k;
len += roundup((res->end - res->start) + 1, PAGE_SIZE);
flags |= res->flags;
}
/* support IORESOURCE_IO _or_ MEM, not both */
if (hweight_long(flags) != 1)
goto bad;
n = len >> PAGE_SHIFT;
if (n >= TRAPPED_PAGES_MAX)
goto bad;
for (k = 0; k < n; k++)
pages[k] = virt_to_page(tiop);
tiop->virt_base = vmap(pages, n, VM_MAP, PAGE_NONE);
if (!tiop->virt_base)
goto bad;
len = 0;
for (k = 0; k < tiop->num_resources; k++) {
res = tiop->resource + k;
pr_info("trapped io 0x%08lx overrides %s 0x%08lx\n",
(unsigned long)(tiop->virt_base + len),
res->flags & IORESOURCE_IO ? "io" : "mmio",
(unsigned long)res->start);
len += roundup((res->end - res->start) + 1, PAGE_SIZE);
}
tiop->magic = IO_TRAPPED_MAGIC;
INIT_LIST_HEAD(&tiop->list);
spin_lock_irq(&trapped_lock);
if (flags & IORESOURCE_IO)
list_add(&tiop->list, &trapped_io);
if (flags & IORESOURCE_MEM)
list_add(&tiop->list, &trapped_mem);
spin_unlock_irq(&trapped_lock);
return 0;
bad:
pr_warning("unable to install trapped io filter\n");
return -1;
}
EXPORT_SYMBOL_GPL(register_trapped_io);
void __iomem *match_trapped_io_handler(struct list_head *list,
unsigned long offset,
unsigned long size)
{
unsigned long voffs;
struct trapped_io *tiop;
struct resource *res;
int k, len;
unsigned long flags;
spin_lock_irqsave(&trapped_lock, flags);
list_for_each_entry(tiop, list, list) {
voffs = 0;
for (k = 0; k < tiop->num_resources; k++) {
res = tiop->resource + k;
if (res->start == offset) {
spin_unlock_irqrestore(&trapped_lock, flags);
return tiop->virt_base + voffs;
}
len = (res->end - res->start) + 1;
voffs += roundup(len, PAGE_SIZE);
}
}
spin_unlock_irqrestore(&trapped_lock, flags);
return NULL;
}
EXPORT_SYMBOL_GPL(match_trapped_io_handler);
static struct trapped_io *lookup_tiop(unsigned long address)
{
pgd_t *pgd_k;
pud_t *pud_k;
pmd_t *pmd_k;
pte_t *pte_k;
pte_t entry;
pgd_k = swapper_pg_dir + pgd_index(address);
if (!pgd_present(*pgd_k))
return NULL;
pud_k = pud_offset(pgd_k, address);
if (!pud_present(*pud_k))
return NULL;
pmd_k = pmd_offset(pud_k, address);
if (!pmd_present(*pmd_k))
return NULL;
pte_k = pte_offset_kernel(pmd_k, address);
entry = *pte_k;
return pfn_to_kaddr(pte_pfn(entry));
}
static unsigned long lookup_address(struct trapped_io *tiop,
unsigned long address)
{
struct resource *res;
unsigned long vaddr = (unsigned long)tiop->virt_base;
unsigned long len;
int k;
for (k = 0; k < tiop->num_resources; k++) {
res = tiop->resource + k;
len = roundup((res->end - res->start) + 1, PAGE_SIZE);
if (address < (vaddr + len))
return res->start + (address - vaddr);
vaddr += len;
}
return 0;
}
static unsigned long long copy_word(unsigned long src_addr, int src_len,
unsigned long dst_addr, int dst_len)
{
unsigned long long tmp = 0;
switch (src_len) {
case 1:
tmp = __raw_readb(src_addr);
break;
case 2:
tmp = __raw_readw(src_addr);
break;
case 4:
tmp = __raw_readl(src_addr);
break;
case 8:
tmp = __raw_readq(src_addr);
break;
}
switch (dst_len) {
case 1:
__raw_writeb(tmp, dst_addr);
break;
case 2:
__raw_writew(tmp, dst_addr);
break;
case 4:
__raw_writel(tmp, dst_addr);
break;
case 8:
__raw_writeq(tmp, dst_addr);
break;
}
return tmp;
}
static unsigned long from_device(void *dst, const void *src, unsigned long cnt)
{
struct trapped_io *tiop;
unsigned long src_addr = (unsigned long)src;
unsigned long long tmp;
pr_debug("trapped io read 0x%08lx (%ld)\n", src_addr, cnt);
tiop = lookup_tiop(src_addr);
WARN_ON(!tiop || (tiop->magic != IO_TRAPPED_MAGIC));
src_addr = lookup_address(tiop, src_addr);
if (!src_addr)
return cnt;
tmp = copy_word(src_addr,
max_t(unsigned long, cnt,
(tiop->minimum_bus_width / 8)),
(unsigned long)dst, cnt);
pr_debug("trapped io read 0x%08lx -> 0x%08llx\n", src_addr, tmp);
return 0;
}
static unsigned long to_device(void *dst, const void *src, unsigned long cnt)
{
struct trapped_io *tiop;
unsigned long dst_addr = (unsigned long)dst;
unsigned long long tmp;
pr_debug("trapped io write 0x%08lx (%ld)\n", dst_addr, cnt);
tiop = lookup_tiop(dst_addr);
WARN_ON(!tiop || (tiop->magic != IO_TRAPPED_MAGIC));
dst_addr = lookup_address(tiop, dst_addr);
if (!dst_addr)
return cnt;
tmp = copy_word((unsigned long)src, cnt,
dst_addr, max_t(unsigned long, cnt,
(tiop->minimum_bus_width / 8)));
pr_debug("trapped io write 0x%08lx -> 0x%08llx\n", dst_addr, tmp);
return 0;
}
static struct mem_access trapped_io_access = {
from_device,
to_device,
};
int handle_trapped_io(struct pt_regs *regs, unsigned long address)
{
mm_segment_t oldfs;
insn_size_t instruction;
int tmp;
if (trapped_io_disable)
return 0;
if (!lookup_tiop(address))
return 0;
WARN_ON(user_mode(regs));
oldfs = get_fs();
set_fs(KERNEL_DS);
if (copy_from_user(&instruction, (void *)(regs->pc),
sizeof(instruction))) {
set_fs(oldfs);
return 0;
}
tmp = handle_unaligned_access(instruction, regs,
&trapped_io_access, 1);
set_fs(oldfs);
return tmp == 0;
}
|
