Commit | Line | Data |
---|---|---|
8b7d89d0 PP |
1 | /* |
2 | * This program is free software; you can redistribute it and/or modify | |
3 | * it under the terms of the GNU General Public License as published by | |
4 | * the Free Software Foundation; either version 2 of the License, or | |
5 | * (at your option) any later version. | |
6 | * | |
7 | * This program is distributed in the hope that it will be useful, | |
8 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
9 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
10 | * GNU General Public License for more details. | |
11 | * | |
12 | * You should have received a copy of the GNU General Public License | |
13 | * along with this program; if not, write to the Free Software | |
14 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. | |
15 | * | |
16 | * Copyright (C) IBM Corporation, 2005 | |
17 | * Jeff Muizelaar, 2006, 2007 | |
18 | * Pekka Paalanen, 2008 <pq@iki.fi> | |
19 | * | |
20 | * Derived from the read-mod example from relay-examples by Tom Zanussi. | |
21 | */ | |
d61fc448 PP |
22 | #define DEBUG 1 |
23 | ||
8b7d89d0 | 24 | #include <linux/module.h> |
8b7d89d0 | 25 | #include <linux/debugfs.h> |
f984b51e | 26 | #include <linux/uaccess.h> |
970e6fa0 | 27 | #include <linux/io.h> |
8b7d89d0 PP |
28 | #include <linux/version.h> |
29 | #include <linux/kallsyms.h> | |
30 | #include <asm/pgtable.h> | |
31 | #include <linux/mmiotrace.h> | |
32 | #include <asm/e820.h> /* for ISA_START_ADDRESS */ | |
fe1ffafa | 33 | #include <asm/atomic.h> |
f5136380 | 34 | #include <linux/percpu.h> |
7423d111 | 35 | #include <linux/cpu.h> |
8b7d89d0 | 36 | |
8b7d89d0 PP |
37 | #include "pf_in.h" |
38 | ||
d61fc448 | 39 | #define NAME "mmiotrace: " |
8b7d89d0 | 40 | |
8b7d89d0 PP |
41 | struct trap_reason { |
42 | unsigned long addr; | |
43 | unsigned long ip; | |
44 | enum reason_type type; | |
45 | int active_traces; | |
46 | }; | |
47 | ||
d61fc448 PP |
48 | struct remap_trace { |
49 | struct list_head list; | |
50 | struct kmmio_probe probe; | |
51 | unsigned long phys; | |
52 | unsigned long id; | |
53 | }; | |
54 | ||
fe1ffafa | 55 | /* Accessed per-cpu. */ |
f5136380 | 56 | static DEFINE_PER_CPU(struct trap_reason, pf_reason); |
bd8ac686 | 57 | static DEFINE_PER_CPU(struct mmiotrace_rw, cpu_trace); |
8b7d89d0 | 58 | |
f984b51e | 59 | #if 0 /* XXX: no way gather this info anymore */ |
fe1ffafa | 60 | /* Access to this is not per-cpu. */ |
f5136380 | 61 | static DEFINE_PER_CPU(atomic_t, dropped); |
f984b51e | 62 | #endif |
fe1ffafa | 63 | |
d61fc448 | 64 | static struct dentry *marker_file; |
8b7d89d0 | 65 | |
d61fc448 PP |
66 | static DEFINE_MUTEX(mmiotrace_mutex); |
67 | static DEFINE_SPINLOCK(trace_lock); | |
68 | static atomic_t mmiotrace_enabled; | |
69 | static LIST_HEAD(trace_list); /* struct remap_trace */ | |
d61fc448 PP |
70 | |
71 | /* | |
72 | * Locking in this file: | |
73 | * - mmiotrace_mutex enforces enable/disable_mmiotrace() critical sections. | |
74 | * - mmiotrace_enabled may be modified only when holding mmiotrace_mutex | |
75 | * and trace_lock. | |
76 | * - Routines depending on is_enabled() must take trace_lock. | |
77 | * - trace_list users must hold trace_lock. | |
bd8ac686 | 78 | * - is_enabled() guarantees that mmio_trace_record is allowed. |
d61fc448 PP |
79 | * - pre/post callbacks assume the effect of is_enabled() being true. |
80 | */ | |
8b7d89d0 PP |
81 | |
82 | /* module parameters */ | |
d61fc448 PP |
83 | static unsigned long filter_offset; |
84 | static int nommiotrace; | |
d61fc448 | 85 | static int trace_pc; |
8b7d89d0 | 86 | |
8b7d89d0 PP |
87 | module_param(filter_offset, ulong, 0); |
88 | module_param(nommiotrace, bool, 0); | |
8b7d89d0 PP |
89 | module_param(trace_pc, bool, 0); |
90 | ||
8b7d89d0 PP |
91 | MODULE_PARM_DESC(filter_offset, "Start address of traced mappings."); |
92 | MODULE_PARM_DESC(nommiotrace, "Disable actual MMIO tracing."); | |
8b7d89d0 | 93 | MODULE_PARM_DESC(trace_pc, "Record address of faulting instructions."); |
d61fc448 PP |
94 | |
95 | static bool is_enabled(void) | |
96 | { | |
97 | return atomic_read(&mmiotrace_enabled); | |
98 | } | |
8b7d89d0 | 99 | |
bd8ac686 | 100 | #if 0 /* XXX: needs rewrite */ |
8b7d89d0 | 101 | /* |
d61fc448 | 102 | * Write callback for the debugfs entry: |
8b7d89d0 PP |
103 | * Read a marker and write it to the mmio trace log |
104 | */ | |
d61fc448 PP |
105 | static ssize_t write_marker(struct file *file, const char __user *buffer, |
106 | size_t count, loff_t *ppos) | |
8b7d89d0 PP |
107 | { |
108 | char *event = NULL; | |
109 | struct mm_io_header *headp; | |
d61fc448 | 110 | ssize_t len = (count > 65535) ? 65535 : count; |
8b7d89d0 PP |
111 | |
112 | event = kzalloc(sizeof(*headp) + len, GFP_KERNEL); | |
113 | if (!event) | |
114 | return -ENOMEM; | |
115 | ||
116 | headp = (struct mm_io_header *)event; | |
117 | headp->type = MMIO_MAGIC | (MMIO_MARKER << MMIO_OPCODE_SHIFT); | |
118 | headp->data_len = len; | |
8b7d89d0 PP |
119 | |
120 | if (copy_from_user(event + sizeof(*headp), buffer, len)) { | |
121 | kfree(event); | |
122 | return -EFAULT; | |
123 | } | |
124 | ||
d61fc448 | 125 | spin_lock_irq(&trace_lock); |
f984b51e | 126 | #if 0 /* XXX: convert this to use tracing */ |
d61fc448 PP |
127 | if (is_enabled()) |
128 | relay_write(chan, event, sizeof(*headp) + len); | |
129 | else | |
f984b51e | 130 | #endif |
d61fc448 PP |
131 | len = -EINVAL; |
132 | spin_unlock_irq(&trace_lock); | |
8b7d89d0 PP |
133 | kfree(event); |
134 | return len; | |
135 | } | |
bd8ac686 | 136 | #endif |
8b7d89d0 PP |
137 | |
138 | static void print_pte(unsigned long address) | |
139 | { | |
75bb8835 PP |
140 | int level; |
141 | pte_t *pte = lookup_address(address, &level); | |
142 | ||
143 | if (!pte) { | |
d61fc448 | 144 | pr_err(NAME "Error in %s: no pte for page 0x%08lx\n", |
0fd0e3da | 145 | __func__, address); |
75bb8835 PP |
146 | return; |
147 | } | |
148 | ||
149 | if (level == PG_LEVEL_2M) { | |
d61fc448 PP |
150 | pr_emerg(NAME "4MB pages are not currently supported: " |
151 | "0x%08lx\n", address); | |
8b7d89d0 PP |
152 | BUG(); |
153 | } | |
0663bb6c RD |
154 | pr_info(NAME "pte for 0x%lx: 0x%llx 0x%llx\n", address, |
155 | (unsigned long long)pte_val(*pte), | |
156 | (unsigned long long)pte_val(*pte) & _PAGE_PRESENT); | |
8b7d89d0 PP |
157 | } |
158 | ||
159 | /* | |
160 | * For some reason the pre/post pairs have been called in an | |
161 | * unmatched order. Report and die. | |
162 | */ | |
163 | static void die_kmmio_nesting_error(struct pt_regs *regs, unsigned long addr) | |
164 | { | |
f5136380 | 165 | const struct trap_reason *my_reason = &get_cpu_var(pf_reason); |
d61fc448 PP |
166 | pr_emerg(NAME "unexpected fault for address: 0x%08lx, " |
167 | "last fault for address: 0x%08lx\n", | |
f5136380 | 168 | addr, my_reason->addr); |
8b7d89d0 | 169 | print_pte(addr); |
d61fc448 PP |
170 | print_symbol(KERN_EMERG "faulting IP is at %s\n", regs->ip); |
171 | print_symbol(KERN_EMERG "last faulting IP was at %s\n", my_reason->ip); | |
8b7d89d0 | 172 | #ifdef __i386__ |
0fd0e3da | 173 | pr_emerg("eax: %08lx ebx: %08lx ecx: %08lx edx: %08lx\n", |
8b7d89d0 | 174 | regs->ax, regs->bx, regs->cx, regs->dx); |
0fd0e3da | 175 | pr_emerg("esi: %08lx edi: %08lx ebp: %08lx esp: %08lx\n", |
8b7d89d0 PP |
176 | regs->si, regs->di, regs->bp, regs->sp); |
177 | #else | |
0fd0e3da | 178 | pr_emerg("rax: %016lx rcx: %016lx rdx: %016lx\n", |
8b7d89d0 | 179 | regs->ax, regs->cx, regs->dx); |
0fd0e3da | 180 | pr_emerg("rsi: %016lx rdi: %016lx rbp: %016lx rsp: %016lx\n", |
8b7d89d0 PP |
181 | regs->si, regs->di, regs->bp, regs->sp); |
182 | #endif | |
f5136380 | 183 | put_cpu_var(pf_reason); |
8b7d89d0 PP |
184 | BUG(); |
185 | } | |
186 | ||
187 | static void pre(struct kmmio_probe *p, struct pt_regs *regs, | |
188 | unsigned long addr) | |
189 | { | |
f5136380 | 190 | struct trap_reason *my_reason = &get_cpu_var(pf_reason); |
bd8ac686 | 191 | struct mmiotrace_rw *my_trace = &get_cpu_var(cpu_trace); |
8b7d89d0 PP |
192 | const unsigned long instptr = instruction_pointer(regs); |
193 | const enum reason_type type = get_ins_type(instptr); | |
bd8ac686 | 194 | struct remap_trace *trace = p->user_data; |
8b7d89d0 PP |
195 | |
196 | /* it doesn't make sense to have more than one active trace per cpu */ | |
f5136380 | 197 | if (my_reason->active_traces) |
8b7d89d0 PP |
198 | die_kmmio_nesting_error(regs, addr); |
199 | else | |
f5136380 | 200 | my_reason->active_traces++; |
8b7d89d0 | 201 | |
f5136380 PP |
202 | my_reason->type = type; |
203 | my_reason->addr = addr; | |
204 | my_reason->ip = instptr; | |
8b7d89d0 | 205 | |
bd8ac686 PP |
206 | my_trace->phys = addr - trace->probe.addr + trace->phys; |
207 | my_trace->map_id = trace->id; | |
8b7d89d0 PP |
208 | |
209 | /* | |
210 | * Only record the program counter when requested. | |
211 | * It may taint clean-room reverse engineering. | |
212 | */ | |
213 | if (trace_pc) | |
bd8ac686 | 214 | my_trace->pc = instptr; |
8b7d89d0 | 215 | else |
bd8ac686 | 216 | my_trace->pc = 0; |
8b7d89d0 | 217 | |
f984b51e PP |
218 | /* |
219 | * XXX: the timestamp recorded will be *after* the tracing has been | |
220 | * done, not at the time we hit the instruction. SMP implications | |
221 | * on event ordering? | |
222 | */ | |
8b7d89d0 PP |
223 | |
224 | switch (type) { | |
225 | case REG_READ: | |
bd8ac686 PP |
226 | my_trace->opcode = MMIO_READ; |
227 | my_trace->width = get_ins_mem_width(instptr); | |
8b7d89d0 PP |
228 | break; |
229 | case REG_WRITE: | |
bd8ac686 PP |
230 | my_trace->opcode = MMIO_WRITE; |
231 | my_trace->width = get_ins_mem_width(instptr); | |
232 | my_trace->value = get_ins_reg_val(instptr, regs); | |
8b7d89d0 PP |
233 | break; |
234 | case IMM_WRITE: | |
bd8ac686 PP |
235 | my_trace->opcode = MMIO_WRITE; |
236 | my_trace->width = get_ins_mem_width(instptr); | |
237 | my_trace->value = get_ins_imm_val(instptr); | |
8b7d89d0 PP |
238 | break; |
239 | default: | |
240 | { | |
241 | unsigned char *ip = (unsigned char *)instptr; | |
bd8ac686 PP |
242 | my_trace->opcode = MMIO_UNKNOWN_OP; |
243 | my_trace->width = 0; | |
244 | my_trace->value = (*ip) << 16 | *(ip + 1) << 8 | | |
f5136380 | 245 | *(ip + 2); |
8b7d89d0 PP |
246 | } |
247 | } | |
f5136380 PP |
248 | put_cpu_var(cpu_trace); |
249 | put_cpu_var(pf_reason); | |
8b7d89d0 PP |
250 | } |
251 | ||
252 | static void post(struct kmmio_probe *p, unsigned long condition, | |
253 | struct pt_regs *regs) | |
254 | { | |
f5136380 | 255 | struct trap_reason *my_reason = &get_cpu_var(pf_reason); |
bd8ac686 | 256 | struct mmiotrace_rw *my_trace = &get_cpu_var(cpu_trace); |
8b7d89d0 PP |
257 | |
258 | /* this should always return the active_trace count to 0 */ | |
f5136380 PP |
259 | my_reason->active_traces--; |
260 | if (my_reason->active_traces) { | |
d61fc448 | 261 | pr_emerg(NAME "unexpected post handler"); |
8b7d89d0 PP |
262 | BUG(); |
263 | } | |
264 | ||
f5136380 | 265 | switch (my_reason->type) { |
8b7d89d0 | 266 | case REG_READ: |
bd8ac686 | 267 | my_trace->value = get_ins_reg_val(my_reason->ip, regs); |
8b7d89d0 PP |
268 | break; |
269 | default: | |
270 | break; | |
271 | } | |
f984b51e | 272 | |
bd8ac686 | 273 | mmio_trace_rw(my_trace); |
f5136380 PP |
274 | put_cpu_var(cpu_trace); |
275 | put_cpu_var(pf_reason); | |
8b7d89d0 PP |
276 | } |
277 | ||
d61fc448 | 278 | static void ioremap_trace_core(unsigned long offset, unsigned long size, |
8b7d89d0 PP |
279 | void __iomem *addr) |
280 | { | |
d61fc448 | 281 | static atomic_t next_id; |
8b7d89d0 | 282 | struct remap_trace *trace = kmalloc(sizeof(*trace), GFP_KERNEL); |
87e547fe | 283 | /* These are page-unaligned. */ |
bd8ac686 PP |
284 | struct mmiotrace_map map = { |
285 | .phys = offset, | |
286 | .virt = (unsigned long)addr, | |
287 | .len = size, | |
288 | .opcode = MMIO_PROBE | |
8b7d89d0 | 289 | }; |
8b7d89d0 | 290 | |
d61fc448 PP |
291 | if (!trace) { |
292 | pr_err(NAME "kmalloc failed in ioremap\n"); | |
293 | return; | |
294 | } | |
295 | ||
8b7d89d0 PP |
296 | *trace = (struct remap_trace) { |
297 | .probe = { | |
298 | .addr = (unsigned long)addr, | |
299 | .len = size, | |
300 | .pre_handler = pre, | |
301 | .post_handler = post, | |
d61fc448 PP |
302 | .user_data = trace |
303 | }, | |
304 | .phys = offset, | |
305 | .id = atomic_inc_return(&next_id) | |
8b7d89d0 | 306 | }; |
bd8ac686 | 307 | map.map_id = trace->id; |
8b7d89d0 | 308 | |
d61fc448 PP |
309 | spin_lock_irq(&trace_lock); |
310 | if (!is_enabled()) | |
311 | goto not_enabled; | |
312 | ||
bd8ac686 | 313 | mmio_trace_mapping(&map); |
8b7d89d0 | 314 | list_add_tail(&trace->list, &trace_list); |
8b7d89d0 PP |
315 | if (!nommiotrace) |
316 | register_kmmio_probe(&trace->probe); | |
d61fc448 PP |
317 | |
318 | not_enabled: | |
319 | spin_unlock_irq(&trace_lock); | |
8b7d89d0 PP |
320 | } |
321 | ||
d61fc448 PP |
322 | void |
323 | mmiotrace_ioremap(unsigned long offset, unsigned long size, void __iomem *addr) | |
8b7d89d0 | 324 | { |
d61fc448 | 325 | if (!is_enabled()) /* recheck and proper locking in *_core() */ |
8b7d89d0 PP |
326 | return; |
327 | ||
d61fc448 PP |
328 | pr_debug(NAME "ioremap_*(0x%lx, 0x%lx) = %p\n", offset, size, addr); |
329 | if ((filter_offset) && (offset != filter_offset)) | |
8b7d89d0 | 330 | return; |
d61fc448 | 331 | ioremap_trace_core(offset, size, addr); |
8b7d89d0 | 332 | } |
8b7d89d0 | 333 | |
d61fc448 | 334 | static void iounmap_trace_core(volatile void __iomem *addr) |
8b7d89d0 | 335 | { |
bd8ac686 PP |
336 | struct mmiotrace_map map = { |
337 | .phys = 0, | |
338 | .virt = (unsigned long)addr, | |
339 | .len = 0, | |
340 | .opcode = MMIO_UNPROBE | |
8b7d89d0 PP |
341 | }; |
342 | struct remap_trace *trace; | |
343 | struct remap_trace *tmp; | |
d61fc448 PP |
344 | struct remap_trace *found_trace = NULL; |
345 | ||
346 | pr_debug(NAME "Unmapping %p.\n", addr); | |
8b7d89d0 | 347 | |
d61fc448 PP |
348 | spin_lock_irq(&trace_lock); |
349 | if (!is_enabled()) | |
350 | goto not_enabled; | |
351 | ||
8b7d89d0 PP |
352 | list_for_each_entry_safe(trace, tmp, &trace_list, list) { |
353 | if ((unsigned long)addr == trace->probe.addr) { | |
354 | if (!nommiotrace) | |
355 | unregister_kmmio_probe(&trace->probe); | |
356 | list_del(&trace->list); | |
d61fc448 | 357 | found_trace = trace; |
8b7d89d0 PP |
358 | break; |
359 | } | |
360 | } | |
bd8ac686 PP |
361 | map.map_id = (found_trace) ? found_trace->id : -1; |
362 | mmio_trace_mapping(&map); | |
d61fc448 PP |
363 | |
364 | not_enabled: | |
365 | spin_unlock_irq(&trace_lock); | |
366 | if (found_trace) { | |
367 | synchronize_rcu(); /* unregister_kmmio_probe() requirement */ | |
368 | kfree(found_trace); | |
369 | } | |
370 | } | |
371 | ||
372 | void mmiotrace_iounmap(volatile void __iomem *addr) | |
373 | { | |
374 | might_sleep(); | |
375 | if (is_enabled()) /* recheck and proper locking in *_core() */ | |
376 | iounmap_trace_core(addr); | |
8b7d89d0 | 377 | } |
8b7d89d0 PP |
378 | |
379 | static void clear_trace_list(void) | |
380 | { | |
381 | struct remap_trace *trace; | |
382 | struct remap_trace *tmp; | |
383 | ||
d61fc448 PP |
384 | /* |
385 | * No locking required, because the caller ensures we are in a | |
386 | * critical section via mutex, and is_enabled() is false, | |
387 | * i.e. nothing can traverse or modify this list. | |
388 | * Caller also ensures is_enabled() cannot change. | |
389 | */ | |
390 | list_for_each_entry(trace, &trace_list, list) { | |
391 | pr_notice(NAME "purging non-iounmapped " | |
8b7d89d0 PP |
392 | "trace @0x%08lx, size 0x%lx.\n", |
393 | trace->probe.addr, trace->probe.len); | |
394 | if (!nommiotrace) | |
395 | unregister_kmmio_probe(&trace->probe); | |
d61fc448 PP |
396 | } |
397 | synchronize_rcu(); /* unregister_kmmio_probe() requirement */ | |
398 | ||
399 | list_for_each_entry_safe(trace, tmp, &trace_list, list) { | |
8b7d89d0 PP |
400 | list_del(&trace->list); |
401 | kfree(trace); | |
d61fc448 PP |
402 | } |
403 | } | |
404 | ||
7423d111 PP |
405 | #ifdef CONFIG_HOTPLUG_CPU |
406 | static cpumask_t downed_cpus; | |
407 | ||
408 | static void enter_uniprocessor(void) | |
409 | { | |
410 | int cpu; | |
411 | int err; | |
412 | ||
413 | get_online_cpus(); | |
414 | downed_cpus = cpu_online_map; | |
415 | cpu_clear(first_cpu(cpu_online_map), downed_cpus); | |
416 | if (num_online_cpus() > 1) | |
417 | pr_notice(NAME "Disabling non-boot CPUs...\n"); | |
418 | put_online_cpus(); | |
419 | ||
420 | for_each_cpu_mask(cpu, downed_cpus) { | |
421 | err = cpu_down(cpu); | |
970e6fa0 | 422 | if (!err) |
7423d111 | 423 | pr_info(NAME "CPU%d is down.\n", cpu); |
970e6fa0 | 424 | else |
7423d111 | 425 | pr_err(NAME "Error taking CPU%d down: %d\n", cpu, err); |
7423d111 PP |
426 | } |
427 | if (num_online_cpus() > 1) | |
428 | pr_warning(NAME "multiple CPUs still online, " | |
429 | "may miss events.\n"); | |
430 | } | |
431 | ||
432 | static void leave_uniprocessor(void) | |
433 | { | |
434 | int cpu; | |
435 | int err; | |
436 | ||
437 | if (cpus_weight(downed_cpus) == 0) | |
438 | return; | |
439 | pr_notice(NAME "Re-enabling CPUs...\n"); | |
440 | for_each_cpu_mask(cpu, downed_cpus) { | |
441 | err = cpu_up(cpu); | |
442 | if (!err) | |
443 | pr_info(NAME "enabled CPU%d.\n", cpu); | |
444 | else | |
445 | pr_err(NAME "cannot re-enable CPU%d: %d\n", cpu, err); | |
446 | } | |
447 | } | |
448 | ||
449 | #else /* !CONFIG_HOTPLUG_CPU */ | |
450 | static void enter_uniprocessor(void) | |
451 | { | |
452 | if (num_online_cpus() > 1) | |
453 | pr_warning(NAME "multiple CPUs are online, may miss events. " | |
454 | "Suggest booting with maxcpus=1 kernel argument.\n"); | |
455 | } | |
456 | ||
457 | static void leave_uniprocessor(void) | |
458 | { | |
459 | } | |
460 | #endif | |
461 | ||
bd8ac686 | 462 | #if 0 /* XXX: out of order */ |
d61fc448 PP |
463 | static struct file_operations fops_marker = { |
464 | .owner = THIS_MODULE, | |
465 | .write = write_marker | |
466 | }; | |
bd8ac686 | 467 | #endif |
d61fc448 | 468 | |
f984b51e | 469 | void enable_mmiotrace(void) |
d61fc448 PP |
470 | { |
471 | mutex_lock(&mmiotrace_mutex); | |
472 | if (is_enabled()) | |
473 | goto out; | |
474 | ||
f984b51e | 475 | #if 0 /* XXX: tracing does not support text entries */ |
d61fc448 PP |
476 | marker_file = debugfs_create_file("marker", 0660, dir, NULL, |
477 | &fops_marker); | |
478 | if (!marker_file) | |
479 | pr_err(NAME "marker file creation failed.\n"); | |
bd8ac686 | 480 | #endif |
d61fc448 PP |
481 | |
482 | if (nommiotrace) | |
483 | pr_info(NAME "MMIO tracing disabled.\n"); | |
7423d111 | 484 | enter_uniprocessor(); |
d61fc448 PP |
485 | spin_lock_irq(&trace_lock); |
486 | atomic_inc(&mmiotrace_enabled); | |
487 | spin_unlock_irq(&trace_lock); | |
488 | pr_info(NAME "enabled.\n"); | |
489 | out: | |
490 | mutex_unlock(&mmiotrace_mutex); | |
491 | } | |
492 | ||
f984b51e | 493 | void disable_mmiotrace(void) |
d61fc448 PP |
494 | { |
495 | mutex_lock(&mmiotrace_mutex); | |
496 | if (!is_enabled()) | |
497 | goto out; | |
498 | ||
499 | spin_lock_irq(&trace_lock); | |
500 | atomic_dec(&mmiotrace_enabled); | |
501 | BUG_ON(is_enabled()); | |
502 | spin_unlock_irq(&trace_lock); | |
503 | ||
504 | clear_trace_list(); /* guarantees: no more kmmio callbacks */ | |
7423d111 | 505 | leave_uniprocessor(); |
d61fc448 PP |
506 | if (marker_file) { |
507 | debugfs_remove(marker_file); | |
508 | marker_file = NULL; | |
509 | } | |
d61fc448 PP |
510 | |
511 | pr_info(NAME "disabled.\n"); | |
512 | out: | |
513 | mutex_unlock(&mmiotrace_mutex); | |
8b7d89d0 | 514 | } |