1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Remote Processor Framework
  4 *
  5 * Copyright (C) 2011 Texas Instruments, Inc.
  6 * Copyright (C) 2011 Google, Inc.
  7 *
  8 * Ohad Ben-Cohen <ohad@wizery.com>
  9 * Mark Grosen <mgrosen@ti.com>
 10 * Brian Swetland <swetland@google.com>
 11 * Fernando Guzman Lugo <fernando.lugo@ti.com>
 12 * Suman Anna <s-anna@ti.com>
 13 * Robert Tivy <rtivy@ti.com>
 14 * Armando Uribe De Leon <x0095078@ti.com>
 15 */
 16
 17#define pr_fmt(fmt)    "%s: " fmt, __func__
 18
 19#include <linux/kernel.h>
 20#include <linux/debugfs.h>
 21#include <linux/remoteproc.h>
 22#include <linux/device.h>
 23#include <linux/uaccess.h>
 24
 25#include "remoteproc_internal.h"
 26
 27/* remoteproc debugfs parent dir */
 28static struct dentry *rproc_dbg;
 29
 30/*
 31 * A coredump-configuration-to-string lookup table, for exposing a
 32 * human readable configuration via debugfs. Always keep in sync with
 33 * enum rproc_coredump_mechanism
 34 */
 35static const char * const rproc_coredump_str[] = {
 36	[RPROC_COREDUMP_DISABLED]	= "disabled",
 37	[RPROC_COREDUMP_ENABLED]	= "enabled",
 38	[RPROC_COREDUMP_INLINE]		= "inline",
 39};
 40
 41/* Expose the current coredump configuration via debugfs */
 42static ssize_t rproc_coredump_read(struct file *filp, char __user *userbuf,
 43				   size_t count, loff_t *ppos)
 44{
 45	struct rproc *rproc = filp->private_data;
 46	char buf[20];
 47	int len;
 48
 49	len = scnprintf(buf, sizeof(buf), "%s\n",
 50			rproc_coredump_str[rproc->dump_conf]);
 51
 52	return simple_read_from_buffer(userbuf, count, ppos, buf, len);
 53}
 54
 55/*
 56 * By writing to the 'coredump' debugfs entry, we control the behavior of the
 57 * coredump mechanism dynamically. The default value of this entry is "disabled".
 58 *
 59 * The 'coredump' debugfs entry supports these commands:
 60 *
 61 * disabled:	By default coredump collection is disabled. Recovery will
 62 *		proceed without collecting any dump.
 63 *
 64 * enabled:	When the remoteproc crashes the entire coredump will be copied
 65 *		to a separate buffer and exposed to userspace.
 66 *
 67 * inline:	The coredump will not be copied to a separate buffer and the
 68 *		recovery process will have to wait until data is read by
 69 *		userspace. But this avoid usage of extra memory.
 70 */
 71static ssize_t rproc_coredump_write(struct file *filp,
 72				    const char __user *user_buf, size_t count,
 73				    loff_t *ppos)
 74{
 75	struct rproc *rproc = filp->private_data;
 76	int ret, err = 0;
 77	char buf[20];
 78
 79	if (count < 1 || count > sizeof(buf))
 80		return -EINVAL;
 81
 82	ret = copy_from_user(buf, user_buf, count);
 83	if (ret)
 84		return -EFAULT;
 85
 86	/* remove end of line */
 87	if (buf[count - 1] == '\n')
 88		buf[count - 1] = '\0';
 89
 90	if (rproc->state == RPROC_CRASHED) {
 91		dev_err(&rproc->dev, "can't change coredump configuration\n");
 92		err = -EBUSY;
 93		goto out;
 94	}
 95
 96	if (!strncmp(buf, "disabled", count)) {
 97		rproc->dump_conf = RPROC_COREDUMP_DISABLED;
 98	} else if (!strncmp(buf, "enabled", count)) {
 99		rproc->dump_conf = RPROC_COREDUMP_ENABLED;
100	} else if (!strncmp(buf, "inline", count)) {
101		rproc->dump_conf = RPROC_COREDUMP_INLINE;
102	} else {
103		dev_err(&rproc->dev, "Invalid coredump configuration\n");
104		err = -EINVAL;
105	}
106out:
107	return err ? err : count;
108}
109
110static const struct file_operations rproc_coredump_fops = {
111	.read = rproc_coredump_read,
112	.write = rproc_coredump_write,
113	.open = simple_open,
114	.llseek = generic_file_llseek,
115};
116
117/*
118 * Some remote processors may support dumping trace logs into a shared
119 * memory buffer. We expose this trace buffer using debugfs, so users
120 * can easily tell what's going on remotely.
121 *
122 * We will most probably improve the rproc tracing facilities later on,
123 * but this kind of lightweight and simple mechanism is always good to have,
124 * as it provides very early tracing with little to no dependencies at all.
125 */
126static ssize_t rproc_trace_read(struct file *filp, char __user *userbuf,
127				size_t count, loff_t *ppos)
128{
129	struct rproc_debug_trace *data = filp->private_data;
130	struct rproc_mem_entry *trace = &data->trace_mem;
131	void *va;
132	char buf[100];
133	int len;
134
135	va = rproc_da_to_va(data->rproc, trace->da, trace->len, NULL);
136
137	if (!va) {
138		len = scnprintf(buf, sizeof(buf), "Trace %s not available\n",
139				trace->name);
140		va = buf;
141	} else {
142		len = strnlen(va, trace->len);
143	}
144
145	return simple_read_from_buffer(userbuf, count, ppos, va, len);
146}
147
148static const struct file_operations trace_rproc_ops = {
149	.read = rproc_trace_read,
150	.open = simple_open,
151	.llseek	= generic_file_llseek,
152};
153
154/* expose the name of the remote processor via debugfs */
155static ssize_t rproc_name_read(struct file *filp, char __user *userbuf,
156			       size_t count, loff_t *ppos)
157{
158	struct rproc *rproc = filp->private_data;
159	/* need room for the name, a newline and a terminating null */
160	char buf[100];
161	int i;
162
163	i = scnprintf(buf, sizeof(buf), "%.98s\n", rproc->name);
164
165	return simple_read_from_buffer(userbuf, count, ppos, buf, i);
166}
167
168static const struct file_operations rproc_name_ops = {
169	.read = rproc_name_read,
170	.open = simple_open,
171	.llseek	= generic_file_llseek,
172};
173
174/* expose recovery flag via debugfs */
175static ssize_t rproc_recovery_read(struct file *filp, char __user *userbuf,
176				   size_t count, loff_t *ppos)
177{
178	struct rproc *rproc = filp->private_data;
179	char *buf = rproc->recovery_disabled ? "disabled\n" : "enabled\n";
180
181	return simple_read_from_buffer(userbuf, count, ppos, buf, strlen(buf));
182}
183
184/*
185 * By writing to the 'recovery' debugfs entry, we control the behavior of the
186 * recovery mechanism dynamically. The default value of this entry is "enabled".
187 *
188 * The 'recovery' debugfs entry supports these commands:
189 *
190 * enabled:	When enabled, the remote processor will be automatically
191 *		recovered whenever it crashes. Moreover, if the remote
192 *		processor crashes while recovery is disabled, it will
193 *		be automatically recovered too as soon as recovery is enabled.
194 *
195 * disabled:	When disabled, a remote processor will remain in a crashed
196 *		state if it crashes. This is useful for debugging purposes;
197 *		without it, debugging a crash is substantially harder.
198 *
199 * recover:	This function will trigger an immediate recovery if the
200 *		remote processor is in a crashed state, without changing
201 *		or checking the recovery state (enabled/disabled).
202 *		This is useful during debugging sessions, when one expects
203 *		additional crashes to happen after enabling recovery. In this
204 *		case, enabling recovery will make it hard to debug subsequent
205 *		crashes, so it's recommended to keep recovery disabled, and
206 *		instead use the "recover" command as needed.
207 */
208static ssize_t
209rproc_recovery_write(struct file *filp, const char __user *user_buf,
210		     size_t count, loff_t *ppos)
211{
212	struct rproc *rproc = filp->private_data;
213	char buf[10];
214	int ret;
215
216	if (count < 1 || count > sizeof(buf))
217		return -EINVAL;
218
219	ret = copy_from_user(buf, user_buf, count);
220	if (ret)
221		return -EFAULT;
222
223	/* remove end of line */
224	if (buf[count - 1] == '\n')
225		buf[count - 1] = '\0';
226
227	if (!strncmp(buf, "enabled", count)) {
228		/* change the flag and begin the recovery process if needed */
229		rproc->recovery_disabled = false;
230		rproc_trigger_recovery(rproc);
231	} else if (!strncmp(buf, "disabled", count)) {
232		rproc->recovery_disabled = true;
233	} else if (!strncmp(buf, "recover", count)) {
234		/* begin the recovery process without changing the flag */
235		rproc_trigger_recovery(rproc);
236	} else {
237		return -EINVAL;
238	}
239
240	return count;
241}
242
243static const struct file_operations rproc_recovery_ops = {
244	.read = rproc_recovery_read,
245	.write = rproc_recovery_write,
246	.open = simple_open,
247	.llseek = generic_file_llseek,
248};
249
250/* expose the crash trigger via debugfs */
251static ssize_t
252rproc_crash_write(struct file *filp, const char __user *user_buf,
253		  size_t count, loff_t *ppos)
254{
255	struct rproc *rproc = filp->private_data;
256	unsigned int type;
257	int ret;
258
259	ret = kstrtouint_from_user(user_buf, count, 0, &type);
260	if (ret < 0)
261		return ret;
262
263	rproc_report_crash(rproc, type);
264
265	return count;
266}
267
268static const struct file_operations rproc_crash_ops = {
269	.write = rproc_crash_write,
270	.open = simple_open,
271	.llseek = generic_file_llseek,
272};
273
274/* Expose resource table content via debugfs */
275static int rproc_rsc_table_show(struct seq_file *seq, void *p)
276{
277	static const char * const types[] = {"carveout", "devmem", "trace", "vdev"};
278	struct rproc *rproc = seq->private;
279	struct resource_table *table = rproc->table_ptr;
280	struct fw_rsc_carveout *c;
281	struct fw_rsc_devmem *d;
282	struct fw_rsc_trace *t;
283	struct fw_rsc_vdev *v;
284	int i, j;
285
286	if (!table) {
287		seq_puts(seq, "No resource table found\n");
288		return 0;
289	}
290
291	for (i = 0; i < table->num; i++) {
292		int offset = table->offset[i];
293		struct fw_rsc_hdr *hdr = (void *)table + offset;
294		void *rsc = (void *)hdr + sizeof(*hdr);
295
296		switch (hdr->type) {
297		case RSC_CARVEOUT:
298			c = rsc;
299			seq_printf(seq, "Entry %d is of type %s\n", i, types[hdr->type]);
300			seq_printf(seq, "  Device Address 0x%x\n", c->da);
301			seq_printf(seq, "  Physical Address 0x%x\n", c->pa);
302			seq_printf(seq, "  Length 0x%x Bytes\n", c->len);
303			seq_printf(seq, "  Flags 0x%x\n", c->flags);
304			seq_printf(seq, "  Reserved (should be zero) [%d]\n", c->reserved);
305			seq_printf(seq, "  Name %s\n\n", c->name);
306			break;
307		case RSC_DEVMEM:
308			d = rsc;
309			seq_printf(seq, "Entry %d is of type %s\n", i, types[hdr->type]);
310			seq_printf(seq, "  Device Address 0x%x\n", d->da);
311			seq_printf(seq, "  Physical Address 0x%x\n", d->pa);
312			seq_printf(seq, "  Length 0x%x Bytes\n", d->len);
313			seq_printf(seq, "  Flags 0x%x\n", d->flags);
314			seq_printf(seq, "  Reserved (should be zero) [%d]\n", d->reserved);
315			seq_printf(seq, "  Name %s\n\n", d->name);
316			break;
317		case RSC_TRACE:
318			t = rsc;
319			seq_printf(seq, "Entry %d is of type %s\n", i, types[hdr->type]);
320			seq_printf(seq, "  Device Address 0x%x\n", t->da);
321			seq_printf(seq, "  Length 0x%x Bytes\n", t->len);
322			seq_printf(seq, "  Reserved (should be zero) [%d]\n", t->reserved);
323			seq_printf(seq, "  Name %s\n\n", t->name);
324			break;
325		case RSC_VDEV:
326			v = rsc;
327			seq_printf(seq, "Entry %d is of type %s\n", i, types[hdr->type]);
328
329			seq_printf(seq, "  ID %d\n", v->id);
330			seq_printf(seq, "  Notify ID %d\n", v->notifyid);
331			seq_printf(seq, "  Device features 0x%x\n", v->dfeatures);
332			seq_printf(seq, "  Guest features 0x%x\n", v->gfeatures);
333			seq_printf(seq, "  Config length 0x%x\n", v->config_len);
334			seq_printf(seq, "  Status 0x%x\n", v->status);
335			seq_printf(seq, "  Number of vrings %d\n", v->num_of_vrings);
336			seq_printf(seq, "  Reserved (should be zero) [%d][%d]\n\n",
337				   v->reserved[0], v->reserved[1]);
338
339			for (j = 0; j < v->num_of_vrings; j++) {
340				seq_printf(seq, "  Vring %d\n", j);
341				seq_printf(seq, "    Device Address 0x%x\n", v->vring[j].da);
342				seq_printf(seq, "    Alignment %d\n", v->vring[j].align);
343				seq_printf(seq, "    Number of buffers %d\n", v->vring[j].num);
344				seq_printf(seq, "    Notify ID %d\n", v->vring[j].notifyid);
345				seq_printf(seq, "    Physical Address 0x%x\n\n",
346					   v->vring[j].pa);
347			}
348			break;
349		default:
350			seq_printf(seq, "Unknown resource type found: %d [hdr: %pK]\n",
351				   hdr->type, hdr);
352			break;
353		}
354	}
355
356	return 0;
357}
358
359DEFINE_SHOW_ATTRIBUTE(rproc_rsc_table);
360
361/* Expose carveout content via debugfs */
362static int rproc_carveouts_show(struct seq_file *seq, void *p)
363{
364	struct rproc *rproc = seq->private;
365	struct rproc_mem_entry *carveout;
366
367	list_for_each_entry(carveout, &rproc->carveouts, node) {
368		seq_puts(seq, "Carveout memory entry:\n");
369		seq_printf(seq, "\tName: %s\n", carveout->name);
370		seq_printf(seq, "\tVirtual address: %pK\n", carveout->va);
371		seq_printf(seq, "\tDMA address: %pad\n", &carveout->dma);
372		seq_printf(seq, "\tDevice address: 0x%x\n", carveout->da);
373		seq_printf(seq, "\tLength: 0x%zx Bytes\n\n", carveout->len);
374	}
375
376	return 0;
377}
378
379DEFINE_SHOW_ATTRIBUTE(rproc_carveouts);
380
381void rproc_remove_trace_file(struct dentry *tfile)
382{
383	debugfs_remove(tfile);
384}
385
386struct dentry *rproc_create_trace_file(const char *name, struct rproc *rproc,
387				       struct rproc_debug_trace *trace)
388{
389	return debugfs_create_file(name, 0400, rproc->dbg_dir, trace,
390				    &trace_rproc_ops);
391}
392
393void rproc_delete_debug_dir(struct rproc *rproc)
394{
395	debugfs_remove_recursive(rproc->dbg_dir);
396}
397
398void rproc_create_debug_dir(struct rproc *rproc)
399{
400	struct device *dev = &rproc->dev;
401
402	if (!rproc_dbg)
403		return;
404
405	rproc->dbg_dir = debugfs_create_dir(dev_name(dev), rproc_dbg);
406
407	debugfs_create_file("name", 0400, rproc->dbg_dir,
408			    rproc, &rproc_name_ops);
409	debugfs_create_file("recovery", 0600, rproc->dbg_dir,
410			    rproc, &rproc_recovery_ops);
411	debugfs_create_file("crash", 0200, rproc->dbg_dir,
412			    rproc, &rproc_crash_ops);
413	debugfs_create_file("resource_table", 0400, rproc->dbg_dir,
414			    rproc, &rproc_rsc_table_fops);
415	debugfs_create_file("carveout_memories", 0400, rproc->dbg_dir,
416			    rproc, &rproc_carveouts_fops);
417	debugfs_create_file("coredump", 0600, rproc->dbg_dir,
418			    rproc, &rproc_coredump_fops);
419}
420
421void __init rproc_init_debugfs(void)
422{
423	if (debugfs_initialized())
424		rproc_dbg = debugfs_create_dir(KBUILD_MODNAME, NULL);
425}
426
427void __exit rproc_exit_debugfs(void)
428{
429	debugfs_remove(rproc_dbg);
430}