1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (c) 2017 Linaro Limited. All rights reserved.
5 * Author: Leo Yan <leo.yan@linaro.org>
7 #include <linux/amba/bus.h>
8 #include <linux/coresight.h>
10 #include <linux/debugfs.h>
11 #include <linux/delay.h>
12 #include <linux/device.h>
13 #include <linux/err.h>
14 #include <linux/init.h>
16 #include <linux/iopoll.h>
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/moduleparam.h>
20 #include <linux/pm_qos.h>
21 #include <linux/slab.h>
22 #include <linux/smp.h>
23 #include <linux/types.h>
24 #include <linux/uaccess.h>
26 #include "coresight-priv.h"
31 #define EDPCSR_HI 0x0AC
35 #define EDDEVID1 0xFC4
38 #define EDPCSR_PROHIBITED 0xFFFFFFFF
40 /* bits definition for EDPCSR */
41 #define EDPCSR_THUMB BIT(0)
42 #define EDPCSR_ARM_INST_MASK GENMASK(31, 2)
43 #define EDPCSR_THUMB_INST_MASK GENMASK(31, 1)
45 /* bits definition for EDPRCR */
46 #define EDPRCR_COREPURQ BIT(3)
47 #define EDPRCR_CORENPDRQ BIT(0)
49 /* bits definition for EDPRSR */
50 #define EDPRSR_DLK BIT(6)
51 #define EDPRSR_PU BIT(0)
53 /* bits definition for EDVIDSR */
54 #define EDVIDSR_NS BIT(31)
55 #define EDVIDSR_E2 BIT(30)
56 #define EDVIDSR_E3 BIT(29)
57 #define EDVIDSR_HV BIT(28)
58 #define EDVIDSR_VMID GENMASK(7, 0)
61 * bits definition for EDDEVID1:PSCROffset
63 * NOTE: armv8 and armv7 have different definition for the register,
64 * so consolidate the bits definition as below:
66 * 0b0000 - Sample offset applies based on the instruction state, we
67 * rely on EDDEVID to check if EDPCSR is implemented or not
68 * 0b0001 - No offset applies.
69 * 0b0010 - No offset applies, but do not use in AArch32 mode
72 #define EDDEVID1_PCSR_OFFSET_MASK GENMASK(3, 0)
73 #define EDDEVID1_PCSR_OFFSET_INS_SET (0x0)
74 #define EDDEVID1_PCSR_NO_OFFSET_DIS_AARCH32 (0x2)
76 /* bits definition for EDDEVID */
77 #define EDDEVID_PCSAMPLE_MODE GENMASK(3, 0)
78 #define EDDEVID_IMPL_EDPCSR (0x1)
79 #define EDDEVID_IMPL_EDPCSR_EDCIDSR (0x2)
80 #define EDDEVID_IMPL_FULL (0x3)
82 #define DEBUG_WAIT_SLEEP 1000
83 #define DEBUG_WAIT_TIMEOUT 32000
85 struct debug_drvdata
{
102 static DEFINE_MUTEX(debug_lock
);
103 static DEFINE_PER_CPU(struct debug_drvdata
*, debug_drvdata
);
104 static int debug_count
;
105 static struct dentry
*debug_debugfs_dir
;
107 static bool debug_enable
;
108 module_param_named(enable
, debug_enable
, bool, 0600);
109 MODULE_PARM_DESC(enable
, "Control to enable coresight CPU debug functionality");
111 static void debug_os_unlock(struct debug_drvdata
*drvdata
)
113 /* Unlocks the debug registers */
114 writel_relaxed(0x0, drvdata
->base
+ EDOSLAR
);
116 /* Make sure the registers are unlocked before accessing */
121 * According to ARM DDI 0487A.k, before access external debug
122 * registers should firstly check the access permission; if any
123 * below condition has been met then cannot access debug
124 * registers to avoid lockup issue:
126 * - CPU power domain is powered off;
127 * - The OS Double Lock is locked;
129 * By checking EDPRSR can get to know if meet these conditions.
131 static bool debug_access_permitted(struct debug_drvdata
*drvdata
)
133 /* CPU is powered off */
134 if (!(drvdata
->edprsr
& EDPRSR_PU
))
137 /* The OS Double Lock is locked */
138 if (drvdata
->edprsr
& EDPRSR_DLK
)
144 static void debug_force_cpu_powered_up(struct debug_drvdata
*drvdata
)
151 * Send request to power management controller and assert
152 * DBGPWRUPREQ signal; if power management controller has
153 * sane implementation, it should enable CPU power domain
154 * in case CPU is in low power state.
156 edprcr
= readl_relaxed(drvdata
->base
+ EDPRCR
);
157 edprcr
|= EDPRCR_COREPURQ
;
158 writel_relaxed(edprcr
, drvdata
->base
+ EDPRCR
);
160 /* Wait for CPU to be powered up (timeout~=32ms) */
161 if (readx_poll_timeout_atomic(readl_relaxed
, drvdata
->base
+ EDPRSR
,
162 drvdata
->edprsr
, (drvdata
->edprsr
& EDPRSR_PU
),
163 DEBUG_WAIT_SLEEP
, DEBUG_WAIT_TIMEOUT
)) {
165 * Unfortunately the CPU cannot be powered up, so return
166 * back and later has no permission to access other
167 * registers. For this case, should disable CPU low power
168 * states to ensure CPU power domain is enabled!
170 dev_err(drvdata
->dev
, "%s: power up request for CPU%d failed\n",
171 __func__
, drvdata
->cpu
);
176 * At this point the CPU is powered up, so set the no powerdown
177 * request bit so we don't lose power and emulate power down.
179 edprcr
= readl_relaxed(drvdata
->base
+ EDPRCR
);
180 edprcr
|= EDPRCR_COREPURQ
| EDPRCR_CORENPDRQ
;
181 writel_relaxed(edprcr
, drvdata
->base
+ EDPRCR
);
183 drvdata
->edprsr
= readl_relaxed(drvdata
->base
+ EDPRSR
);
185 /* The core power domain got switched off on use, try again */
186 if (unlikely(!(drvdata
->edprsr
& EDPRSR_PU
)))
190 static void debug_read_regs(struct debug_drvdata
*drvdata
)
194 CS_UNLOCK(drvdata
->base
);
197 debug_os_unlock(drvdata
);
199 /* Save EDPRCR register */
200 save_edprcr
= readl_relaxed(drvdata
->base
+ EDPRCR
);
203 * Ensure CPU power domain is enabled to let registers
206 debug_force_cpu_powered_up(drvdata
);
208 if (!debug_access_permitted(drvdata
))
211 drvdata
->edpcsr
= readl_relaxed(drvdata
->base
+ EDPCSR
);
214 * As described in ARM DDI 0487A.k, if the processing
215 * element (PE) is in debug state, or sample-based
216 * profiling is prohibited, EDPCSR reads as 0xFFFFFFFF;
217 * EDCIDSR, EDVIDSR and EDPCSR_HI registers also become
218 * UNKNOWN state. So directly bail out for this case.
220 if (drvdata
->edpcsr
== EDPCSR_PROHIBITED
)
224 * A read of the EDPCSR normally has the side-effect of
225 * indirectly writing to EDCIDSR, EDVIDSR and EDPCSR_HI;
226 * at this point it's safe to read value from them.
228 if (IS_ENABLED(CONFIG_64BIT
))
229 drvdata
->edpcsr_hi
= readl_relaxed(drvdata
->base
+ EDPCSR_HI
);
231 if (drvdata
->edcidsr_present
)
232 drvdata
->edcidsr
= readl_relaxed(drvdata
->base
+ EDCIDSR
);
234 if (drvdata
->edvidsr_present
)
235 drvdata
->edvidsr
= readl_relaxed(drvdata
->base
+ EDVIDSR
);
238 /* Restore EDPRCR register */
239 writel_relaxed(save_edprcr
, drvdata
->base
+ EDPRCR
);
241 CS_LOCK(drvdata
->base
);
245 static unsigned long debug_adjust_pc(struct debug_drvdata
*drvdata
)
247 return (unsigned long)drvdata
->edpcsr_hi
<< 32 |
248 (unsigned long)drvdata
->edpcsr
;
251 static unsigned long debug_adjust_pc(struct debug_drvdata
*drvdata
)
253 unsigned long arm_inst_offset
= 0, thumb_inst_offset
= 0;
256 pc
= (unsigned long)drvdata
->edpcsr
;
258 if (drvdata
->pc_has_offset
) {
260 thumb_inst_offset
= 4;
263 /* Handle thumb instruction */
264 if (pc
& EDPCSR_THUMB
) {
265 pc
= (pc
& EDPCSR_THUMB_INST_MASK
) - thumb_inst_offset
;
270 * Handle arm instruction offset, if the arm instruction
271 * is not 4 byte alignment then it's possible the case
272 * for implementation defined; keep original value for this
273 * case and print info for notice.
276 dev_emerg(drvdata
->dev
,
277 "Instruction offset is implementation defined\n");
279 pc
= (pc
& EDPCSR_ARM_INST_MASK
) - arm_inst_offset
;
285 static void debug_dump_regs(struct debug_drvdata
*drvdata
)
287 struct device
*dev
= drvdata
->dev
;
290 dev_emerg(dev
, " EDPRSR: %08x (Power:%s DLK:%s)\n",
292 drvdata
->edprsr
& EDPRSR_PU
? "On" : "Off",
293 drvdata
->edprsr
& EDPRSR_DLK
? "Lock" : "Unlock");
295 if (!debug_access_permitted(drvdata
)) {
296 dev_emerg(dev
, "No permission to access debug registers!\n");
300 if (drvdata
->edpcsr
== EDPCSR_PROHIBITED
) {
301 dev_emerg(dev
, "CPU is in Debug state or profiling is prohibited!\n");
305 pc
= debug_adjust_pc(drvdata
);
306 dev_emerg(dev
, " EDPCSR: %pS\n", (void *)pc
);
308 if (drvdata
->edcidsr_present
)
309 dev_emerg(dev
, " EDCIDSR: %08x\n", drvdata
->edcidsr
);
311 if (drvdata
->edvidsr_present
)
312 dev_emerg(dev
, " EDVIDSR: %08x (State:%s Mode:%s Width:%dbits VMID:%x)\n",
314 drvdata
->edvidsr
& EDVIDSR_NS
?
315 "Non-secure" : "Secure",
316 drvdata
->edvidsr
& EDVIDSR_E3
? "EL3" :
317 (drvdata
->edvidsr
& EDVIDSR_E2
?
319 drvdata
->edvidsr
& EDVIDSR_HV
? 64 : 32,
320 drvdata
->edvidsr
& (u32
)EDVIDSR_VMID
);
323 static void debug_init_arch_data(void *info
)
325 struct debug_drvdata
*drvdata
= info
;
326 u32 mode
, pcsr_offset
;
327 u32 eddevid
, eddevid1
;
329 CS_UNLOCK(drvdata
->base
);
331 /* Read device info */
332 eddevid
= readl_relaxed(drvdata
->base
+ EDDEVID
);
333 eddevid1
= readl_relaxed(drvdata
->base
+ EDDEVID1
);
335 CS_LOCK(drvdata
->base
);
337 /* Parse implementation feature */
338 mode
= eddevid
& EDDEVID_PCSAMPLE_MODE
;
339 pcsr_offset
= eddevid1
& EDDEVID1_PCSR_OFFSET_MASK
;
341 drvdata
->edpcsr_present
= false;
342 drvdata
->edcidsr_present
= false;
343 drvdata
->edvidsr_present
= false;
344 drvdata
->pc_has_offset
= false;
347 case EDDEVID_IMPL_FULL
:
348 drvdata
->edvidsr_present
= true;
350 case EDDEVID_IMPL_EDPCSR_EDCIDSR
:
351 drvdata
->edcidsr_present
= true;
353 case EDDEVID_IMPL_EDPCSR
:
355 * In ARM DDI 0487A.k, the EDDEVID1.PCSROffset is used to
356 * define if has the offset for PC sampling value; if read
357 * back EDDEVID1.PCSROffset == 0x2, then this means the debug
358 * module does not sample the instruction set state when
359 * armv8 CPU in AArch32 state.
361 drvdata
->edpcsr_present
=
362 ((IS_ENABLED(CONFIG_64BIT
) && pcsr_offset
!= 0) ||
363 (pcsr_offset
!= EDDEVID1_PCSR_NO_OFFSET_DIS_AARCH32
));
365 drvdata
->pc_has_offset
=
366 (pcsr_offset
== EDDEVID1_PCSR_OFFSET_INS_SET
);
374 * Dump out information on panic.
376 static int debug_notifier_call(struct notifier_block
*self
,
377 unsigned long v
, void *p
)
380 struct debug_drvdata
*drvdata
;
382 mutex_lock(&debug_lock
);
384 /* Bail out if the functionality is disabled */
388 pr_emerg("ARM external debug module:\n");
390 for_each_possible_cpu(cpu
) {
391 drvdata
= per_cpu(debug_drvdata
, cpu
);
395 dev_emerg(drvdata
->dev
, "CPU[%d]:\n", drvdata
->cpu
);
397 debug_read_regs(drvdata
);
398 debug_dump_regs(drvdata
);
402 mutex_unlock(&debug_lock
);
406 static struct notifier_block debug_notifier
= {
407 .notifier_call
= debug_notifier_call
,
410 static int debug_enable_func(void)
412 struct debug_drvdata
*drvdata
;
417 * Use cpumask to track which debug power domains have
418 * been powered on and use it to handle failure case.
420 cpumask_clear(&mask
);
422 for_each_possible_cpu(cpu
) {
423 drvdata
= per_cpu(debug_drvdata
, cpu
);
427 ret
= pm_runtime_get_sync(drvdata
->dev
);
431 cpumask_set_cpu(cpu
, &mask
);
438 * If pm_runtime_get_sync() has failed, need rollback on
439 * all the other CPUs that have been enabled before that.
441 for_each_cpu(cpu
, &mask
) {
442 drvdata
= per_cpu(debug_drvdata
, cpu
);
443 pm_runtime_put_noidle(drvdata
->dev
);
449 static int debug_disable_func(void)
451 struct debug_drvdata
*drvdata
;
452 int cpu
, ret
, err
= 0;
455 * Disable debug power domains, records the error and keep
456 * circling through all other CPUs when an error has been
459 for_each_possible_cpu(cpu
) {
460 drvdata
= per_cpu(debug_drvdata
, cpu
);
464 ret
= pm_runtime_put(drvdata
->dev
);
472 static ssize_t
debug_func_knob_write(struct file
*f
,
473 const char __user
*buf
, size_t count
, loff_t
*ppos
)
478 ret
= kstrtou8_from_user(buf
, count
, 2, &val
);
482 mutex_lock(&debug_lock
);
484 if (val
== debug_enable
)
488 ret
= debug_enable_func();
490 ret
= debug_disable_func();
493 pr_err("%s: unable to %s debug function: %d\n",
494 __func__
, val
? "enable" : "disable", ret
);
502 mutex_unlock(&debug_lock
);
506 static ssize_t
debug_func_knob_read(struct file
*f
,
507 char __user
*ubuf
, size_t count
, loff_t
*ppos
)
512 mutex_lock(&debug_lock
);
513 snprintf(buf
, sizeof(buf
), "%d\n", debug_enable
);
514 mutex_unlock(&debug_lock
);
516 ret
= simple_read_from_buffer(ubuf
, count
, ppos
, buf
, sizeof(buf
));
520 static const struct file_operations debug_func_knob_fops
= {
522 .read
= debug_func_knob_read
,
523 .write
= debug_func_knob_write
,
526 static int debug_func_init(void)
530 /* Create debugfs node */
531 debug_debugfs_dir
= debugfs_create_dir("coresight_cpu_debug", NULL
);
532 debugfs_create_file("enable", 0644, debug_debugfs_dir
, NULL
,
533 &debug_func_knob_fops
);
535 /* Register function to be called for panic */
536 ret
= atomic_notifier_chain_register(&panic_notifier_list
,
539 pr_err("%s: unable to register notifier: %d\n",
547 debugfs_remove_recursive(debug_debugfs_dir
);
551 static void debug_func_exit(void)
553 atomic_notifier_chain_unregister(&panic_notifier_list
,
555 debugfs_remove_recursive(debug_debugfs_dir
);
558 static int debug_probe(struct amba_device
*adev
, const struct amba_id
*id
)
561 struct device
*dev
= &adev
->dev
;
562 struct debug_drvdata
*drvdata
;
563 struct resource
*res
= &adev
->res
;
566 drvdata
= devm_kzalloc(dev
, sizeof(*drvdata
), GFP_KERNEL
);
570 drvdata
->cpu
= coresight_get_cpu(dev
);
571 if (drvdata
->cpu
< 0)
574 if (per_cpu(debug_drvdata
, drvdata
->cpu
)) {
575 dev_err(dev
, "CPU%d drvdata has already been initialized\n",
580 drvdata
->dev
= &adev
->dev
;
581 amba_set_drvdata(adev
, drvdata
);
583 /* Validity for the resource is already checked by the AMBA core */
584 base
= devm_ioremap_resource(dev
, res
);
586 return PTR_ERR(base
);
588 drvdata
->base
= base
;
591 per_cpu(debug_drvdata
, drvdata
->cpu
) = drvdata
;
592 ret
= smp_call_function_single(drvdata
->cpu
, debug_init_arch_data
,
597 dev_err(dev
, "CPU%d debug arch init failed\n", drvdata
->cpu
);
601 if (!drvdata
->edpcsr_present
) {
602 dev_err(dev
, "CPU%d sample-based profiling isn't implemented\n",
608 if (!debug_count
++) {
609 ret
= debug_func_init();
614 mutex_lock(&debug_lock
);
615 /* Turn off debug power domain if debugging is disabled */
618 mutex_unlock(&debug_lock
);
620 dev_info(dev
, "Coresight debug-CPU%d initialized\n", drvdata
->cpu
);
626 per_cpu(debug_drvdata
, drvdata
->cpu
) = NULL
;
630 static int debug_remove(struct amba_device
*adev
)
632 struct device
*dev
= &adev
->dev
;
633 struct debug_drvdata
*drvdata
= amba_get_drvdata(adev
);
635 per_cpu(debug_drvdata
, drvdata
->cpu
) = NULL
;
637 mutex_lock(&debug_lock
);
638 /* Turn off debug power domain before rmmod the module */
641 mutex_unlock(&debug_lock
);
649 static const struct amba_cs_uci_id uci_id_debug
[] = {
651 /* CPU Debug UCI data */
652 .devarch
= 0x47706a15,
653 .devarch_mask
= 0xfff0ffff,
654 .devtype
= 0x00000015,
658 static const struct amba_id debug_ids
[] = {
659 CS_AMBA_ID(0x000bbd03), /* Cortex-A53 */
660 CS_AMBA_ID(0x000bbd07), /* Cortex-A57 */
661 CS_AMBA_ID(0x000bbd08), /* Cortex-A72 */
662 CS_AMBA_ID(0x000bbd09), /* Cortex-A73 */
663 CS_AMBA_UCI_ID(0x000f0205, uci_id_debug
), /* Qualcomm Kryo */
664 CS_AMBA_UCI_ID(0x000f0211, uci_id_debug
), /* Qualcomm Kryo */
668 MODULE_DEVICE_TABLE(amba
, debug_ids
);
670 static struct amba_driver debug_driver
= {
672 .name
= "coresight-cpu-debug",
673 .suppress_bind_attrs
= true,
675 .probe
= debug_probe
,
676 .remove
= debug_remove
,
677 .id_table
= debug_ids
,
680 module_amba_driver(debug_driver
);
682 MODULE_AUTHOR("Leo Yan <leo.yan@linaro.org>");
683 MODULE_DESCRIPTION("ARM Coresight CPU Debug Driver");
684 MODULE_LICENSE("GPL");