1/*
  2 * Copyright (C) 2016 Red Hat
  3 *
  4 * Permission is hereby granted, free of charge, to any person obtaining a
  5 * copy of this software and associated documentation files (the "Software"),
  6 * to deal in the Software without restriction, including without limitation
  7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  8 * and/or sell copies of the Software, and to permit persons to whom the
  9 * Software is furnished to do so, subject to the following conditions:
 10 *
 11 * The above copyright notice and this permission notice shall be included in
 12 * all copies or substantial portions of the Software.
 13 *
 14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 17 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
 18 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 19 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 20 * OTHER DEALINGS IN THE SOFTWARE.
 21 *
 22 * Authors:
 23 * Rob Clark <robdclark@gmail.com>
 24 */
 25
 26#define DEBUG /* for pr_debug() */
 27
 28#include <stdarg.h>
 29
 30#include <linux/io.h>
 31#include <linux/seq_file.h>
 32#include <linux/slab.h>
 33
 34#include <drm/drm.h>
 35#include <drm/drm_drv.h>
 36#include <drm/drm_print.h>
 37
 38void __drm_puts_coredump(struct drm_printer *p, const char *str)
 39{
 40	struct drm_print_iterator *iterator = p->arg;
 41	ssize_t len;
 42
 43	if (!iterator->remain)
 44		return;
 45
 46	if (iterator->offset < iterator->start) {
 47		ssize_t copy;
 48
 49		len = strlen(str);
 50
 51		if (iterator->offset + len <= iterator->start) {
 52			iterator->offset += len;
 53			return;
 54		}
 55
 56		copy = len - (iterator->start - iterator->offset);
 57
 58		if (copy > iterator->remain)
 59			copy = iterator->remain;
 60
 61		/* Copy out the bit of the string that we need */
 62		memcpy(iterator->data,
 63			str + (iterator->start - iterator->offset), copy);
 64
 65		iterator->offset = iterator->start + copy;
 66		iterator->remain -= copy;
 67	} else {
 68		ssize_t pos = iterator->offset - iterator->start;
 69
 70		len = min_t(ssize_t, strlen(str), iterator->remain);
 71
 72		memcpy(iterator->data + pos, str, len);
 73
 74		iterator->offset += len;
 75		iterator->remain -= len;
 76	}
 77}
 78EXPORT_SYMBOL(__drm_puts_coredump);
 79
 80void __drm_printfn_coredump(struct drm_printer *p, struct va_format *vaf)
 81{
 82	struct drm_print_iterator *iterator = p->arg;
 83	size_t len;
 84	char *buf;
 85
 86	if (!iterator->remain)
 87		return;
 88
 89	/* Figure out how big the string will be */
 90	len = snprintf(NULL, 0, "%pV", vaf);
 91
 92	/* This is the easiest path, we've already advanced beyond the offset */
 93	if (iterator->offset + len <= iterator->start) {
 94		iterator->offset += len;
 95		return;
 96	}
 97
 98	/* Then check if we can directly copy into the target buffer */
 99	if ((iterator->offset >= iterator->start) && (len < iterator->remain)) {
100		ssize_t pos = iterator->offset - iterator->start;
101
102		snprintf(((char *) iterator->data) + pos,
103			iterator->remain, "%pV", vaf);
104
105		iterator->offset += len;
106		iterator->remain -= len;
107
108		return;
109	}
110
111	/*
112	 * Finally, hit the slow path and make a temporary string to copy over
113	 * using _drm_puts_coredump
114	 */
115	buf = kmalloc(len + 1, GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY);
116	if (!buf)
117		return;
118
119	snprintf(buf, len + 1, "%pV", vaf);
120	__drm_puts_coredump(p, (const char *) buf);
121
122	kfree(buf);
123}
124EXPORT_SYMBOL(__drm_printfn_coredump);
125
126void __drm_puts_seq_file(struct drm_printer *p, const char *str)
127{
128	seq_puts(p->arg, str);
129}
130EXPORT_SYMBOL(__drm_puts_seq_file);
131
132void __drm_printfn_seq_file(struct drm_printer *p, struct va_format *vaf)
133{
134	seq_printf(p->arg, "%pV", vaf);
135}
136EXPORT_SYMBOL(__drm_printfn_seq_file);
137
138void __drm_printfn_info(struct drm_printer *p, struct va_format *vaf)
139{
140	dev_info(p->arg, "[" DRM_NAME "] %pV", vaf);
141}
142EXPORT_SYMBOL(__drm_printfn_info);
143
144void __drm_printfn_debug(struct drm_printer *p, struct va_format *vaf)
145{
146	pr_debug("%s %pV", p->prefix, vaf);
147}
148EXPORT_SYMBOL(__drm_printfn_debug);
149
150/**
151 * drm_puts - print a const string to a &drm_printer stream
152 * @p: the &drm printer
153 * @str: const string
154 *
155 * Allow &drm_printer types that have a constant string
156 * option to use it.
157 */
158void drm_puts(struct drm_printer *p, const char *str)
159{
160	if (p->puts)
161		p->puts(p, str);
162	else
163		drm_printf(p, "%s", str);
164}
165EXPORT_SYMBOL(drm_puts);
166
167/**
168 * drm_printf - print to a &drm_printer stream
169 * @p: the &drm_printer
170 * @f: format string
171 */
172void drm_printf(struct drm_printer *p, const char *f, ...)
173{
174	va_list args;
175
176	va_start(args, f);
177	drm_vprintf(p, f, &args);
178	va_end(args);
179}
180EXPORT_SYMBOL(drm_printf);
181
182void drm_dev_printk(const struct device *dev, const char *level,
183		    const char *format, ...)
184{
185	struct va_format vaf;
186	va_list args;
187
188	va_start(args, format);
189	vaf.fmt = format;
190	vaf.va = &args;
191
192	if (dev)
193		dev_printk(level, dev, "[" DRM_NAME ":%ps] %pV",
194			   __builtin_return_address(0), &vaf);
195	else
196		printk("%s" "[" DRM_NAME ":%ps] %pV",
197		       level, __builtin_return_address(0), &vaf);
198
199	va_end(args);
200}
201EXPORT_SYMBOL(drm_dev_printk);
202
203void drm_dev_dbg(const struct device *dev, unsigned int category,
204		 const char *format, ...)
205{
206	struct va_format vaf;
207	va_list args;
208
209	if (!(drm_debug & category))
210		return;
211
212	va_start(args, format);
213	vaf.fmt = format;
214	vaf.va = &args;
215
216	if (dev)
217		dev_printk(KERN_DEBUG, dev, "[" DRM_NAME ":%ps] %pV",
218			   __builtin_return_address(0), &vaf);
219	else
220		printk(KERN_DEBUG "[" DRM_NAME ":%ps] %pV",
221		       __builtin_return_address(0), &vaf);
222
223	va_end(args);
224}
225EXPORT_SYMBOL(drm_dev_dbg);
226
227void drm_dbg(unsigned int category, const char *format, ...)
228{
229	struct va_format vaf;
230	va_list args;
231
232	if (!(drm_debug & category))
233		return;
234
235	va_start(args, format);
236	vaf.fmt = format;
237	vaf.va = &args;
238
239	printk(KERN_DEBUG "[" DRM_NAME ":%ps] %pV",
240	       __builtin_return_address(0), &vaf);
241
242	va_end(args);
243}
244EXPORT_SYMBOL(drm_dbg);
245
246void drm_err(const char *format, ...)
247{
248	struct va_format vaf;
249	va_list args;
250
251	va_start(args, format);
252	vaf.fmt = format;
253	vaf.va = &args;
254
255	printk(KERN_ERR "[" DRM_NAME ":%ps] *ERROR* %pV",
256	       __builtin_return_address(0), &vaf);
257
258	va_end(args);
259}
260EXPORT_SYMBOL(drm_err);
261
262/**
263 * drm_print_regset32 - print the contents of registers to a
264 * &drm_printer stream.
265 *
266 * @p: the &drm printer
267 * @regset: the list of registers to print.
268 *
269 * Often in driver debug, it's useful to be able to either capture the
270 * contents of registers in the steady state using debugfs or at
271 * specific points during operation.  This lets the driver have a
272 * single list of registers for both.
273 */
274void drm_print_regset32(struct drm_printer *p, struct debugfs_regset32 *regset)
275{
276	int namelen = 0;
277	int i;
278
279	for (i = 0; i < regset->nregs; i++)
280		namelen = max(namelen, (int)strlen(regset->regs[i].name));
281
282	for (i = 0; i < regset->nregs; i++) {
283		drm_printf(p, "%*s = 0x%08x\n",
284			   namelen, regset->regs[i].name,
285			   readl(regset->base + regset->regs[i].offset));
286	}
287}
288EXPORT_SYMBOL(drm_print_regset32);