1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/console.h>
3 #include <linux/kernel.h>
4 #include <linux/init.h>
5 #include <linux/string.h>
6 #include <linux/screen_info.h>
7 #include <linux/usb/ch9.h>
8 #include <linux/pci_regs.h>
9 #include <linux/pci_ids.h>
10 #include <linux/errno.h>
11 #include <linux/pgtable.h>
12 #include <asm/io.h>
13 #include <asm/processor.h>
14 #include <asm/fcntl.h>
15 #include <asm/setup.h>
16 #include <xen/hvc-console.h>
17 #include <asm/pci-direct.h>
18 #include <asm/fixmap.h>
19 #include <linux/usb/ehci_def.h>
20 #include <linux/usb/xhci-dbgp.h>
21 #include <asm/pci_x86.h>
22
23 /* Simple VGA output */
24 #define VGABASE (__ISA_IO_base + 0xb8000)
25
26 static int max_ypos = 25, max_xpos = 80;
27 static int current_ypos = 25, current_xpos;
28
29 static void early_vga_write(struct console *con, const char *str, unsigned n)
30 {
31 char c;
32 int i, k, j;
33
34 while ((c = *str++) != '\0' && n-- > 0) {
35 if (current_ypos >= max_ypos) {
36 /* scroll 1 line up */
37 for (k = 1, j = 0; k < max_ypos; k++, j++) {
38 for (i = 0; i < max_xpos; i++) {
39 writew(readw(VGABASE+2*(max_xpos*k+i)),
40 VGABASE + 2*(max_xpos*j + i));
41 }
42 }
43 for (i = 0; i < max_xpos; i++)
44 writew(0x720, VGABASE + 2*(max_xpos*j + i));
45 current_ypos = max_ypos-1;
46 }
47 #ifdef CONFIG_KGDB_KDB
48 if (c == '\b') {
49 if (current_xpos > 0)
50 current_xpos--;
51 } else if (c == '\r') {
52 current_xpos = 0;
53 } else
54 #endif
55 if (c == '\n') {
56 current_xpos = 0;
57 current_ypos++;
58 } else if (c != '\r') {
59 writew(((0x7 << 8) | (unsigned short) c),
60 VGABASE + 2*(max_xpos*current_ypos +
61 current_xpos++));
62 if (current_xpos >= max_xpos) {
63 current_xpos = 0;
64 current_ypos++;
65 }
66 }
67 }
68 }
69
70 static struct console early_vga_console = {
71 .name = "earlyvga",
72 .write = early_vga_write,
73 .flags = CON_PRINTBUFFER,
74 .index = -1,
75 };
76
77 /* Serial functions loosely based on a similar package from Klaus P. Gerlicher */
78
79 static unsigned long early_serial_base = 0x3f8; /* ttyS0 */
80
81 #define XMTRDY 0x20
82
83 #define DLAB 0x80
84
85 #define TXR 0 /* Transmit register (WRITE) */
86 #define RXR 0 /* Receive register (READ) */
87 #define IER 1 /* Interrupt Enable */
88 #define IIR 2 /* Interrupt ID */
89 #define FCR 2 /* FIFO control */
90 #define LCR 3 /* Line control */
91 #define MCR 4 /* Modem control */
92 #define LSR 5 /* Line Status */
93 #define MSR 6 /* Modem Status */
94 #define DLL 0 /* Divisor Latch Low */
95 #define DLH 1 /* Divisor latch High */
96
97 static unsigned int io_serial_in(unsigned long addr, int offset)
98 {
99 return inb(addr + offset);
100 }
101
102 static void io_serial_out(unsigned long addr, int offset, int value)
103 {
104 outb(value, addr + offset);
105 }
106
107 static unsigned int (*serial_in)(unsigned long addr, int offset) = io_serial_in;
108 static void (*serial_out)(unsigned long addr, int offset, int value) = io_serial_out;
109
110 static int early_serial_putc(unsigned char ch)
111 {
112 unsigned timeout = 0xffff;
113
114 while ((serial_in(early_serial_base, LSR) & XMTRDY) == 0 && --timeout)
115 cpu_relax();
116 serial_out(early_serial_base, TXR, ch);
117 return timeout ? 0 : -1;
118 }
119
120 static void early_serial_write(struct console *con, const char *s, unsigned n)
121 {
122 while (*s && n-- > 0) {
123 if (*s == '\n')
124 early_serial_putc('\r');
125 early_serial_putc(*s);
126 s++;
127 }
128 }
129
130 static __init void early_serial_hw_init(unsigned divisor)
131 {
132 unsigned char c;
133
134 serial_out(early_serial_base, LCR, 0x3); /* 8n1 */
135 serial_out(early_serial_base, IER, 0); /* no interrupt */
136 serial_out(early_serial_base, FCR, 0); /* no fifo */
137 serial_out(early_serial_base, MCR, 0x3); /* DTR + RTS */
138
139 c = serial_in(early_serial_base, LCR);
140 serial_out(early_serial_base, LCR, c | DLAB);
141 serial_out(early_serial_base, DLL, divisor & 0xff);
142 serial_out(early_serial_base, DLH, (divisor >> 8) & 0xff);
143 serial_out(early_serial_base, LCR, c & ~DLAB);
144 }
145
146 #define DEFAULT_BAUD 9600
147
148 static __init void early_serial_init(char *s)
149 {
150 unsigned divisor;
151 unsigned long baud = DEFAULT_BAUD;
152 char *e;
153
154 if (*s == ',')
155 ++s;
156
157 if (*s) {
158 unsigned port;
159 if (!strncmp(s, "0x", 2)) {
160 early_serial_base = simple_strtoul(s, &e, 16);
161 } else {
162 static const int __initconst bases[] = { 0x3f8, 0x2f8 };
163
164 if (!strncmp(s, "ttyS", 4))
165 s += 4;
166 port = simple_strtoul(s, &e, 10);
167 if (port > 1 || s == e)
168 port = 0;
169 early_serial_base = bases[port];
170 }
171 s += strcspn(s, ",");
172 if (*s == ',')
173 s++;
174 }
175
176 if (*s) {
177 baud = simple_strtoull(s, &e, 0);
178
179 if (baud == 0 || s == e)
180 baud = DEFAULT_BAUD;
181 }
182
183 /* Convert from baud to divisor value */
184 divisor = 115200 / baud;
185
186 /* These will always be IO based ports */
187 serial_in = io_serial_in;
188 serial_out = io_serial_out;
189
190 /* Set up the HW */
191 early_serial_hw_init(divisor);
192 }
193
194 #ifdef CONFIG_PCI
195 static void mem32_serial_out(unsigned long addr, int offset, int value)
196 {
197 u32 __iomem *vaddr = (u32 __iomem *)addr;
198 /* shift implied by pointer type */
199 writel(value, vaddr + offset);
200 }
201
202 static unsigned int mem32_serial_in(unsigned long addr, int offset)
203 {
204 u32 __iomem *vaddr = (u32 __iomem *)addr;
205 /* shift implied by pointer type */
206 return readl(vaddr + offset);
207 }
208
209 /*
210 * early_pci_serial_init()
211 *
212 * This function is invoked when the early_printk param starts with "pciserial"
213 * The rest of the param should be "[force],B:D.F,baud", where B, D & F describe
214 * the location of a PCI device that must be a UART device. "force" is optional
215 * and overrides the use of an UART device with a wrong PCI class code.
216 */
217 static __init void early_pci_serial_init(char *s)
218 {
219 unsigned divisor;
220 unsigned long baud = DEFAULT_BAUD;
221 u8 bus, slot, func;
222 u32 classcode, bar0;
223 u16 cmdreg;
224 char *e;
225 int force = 0;
226
227 if (*s == ',')
228 ++s;
229
230 if (*s == 0)
231 return;
232
233 /* Force the use of an UART device with wrong class code */
234 if (!strncmp(s, "force,", 6)) {
235 force = 1;
236 s += 6;
237 }
238
239 /*
240 * Part the param to get the BDF values
241 */
242 bus = (u8)simple_strtoul(s, &e, 16);
243 s = e;
244 if (*s != ':')
245 return;
246 ++s;
247 slot = (u8)simple_strtoul(s, &e, 16);
248 s = e;
249 if (*s != '.')
250 return;
251 ++s;
252 func = (u8)simple_strtoul(s, &e, 16);
253 s = e;
254
255 /* A baud might be following */
256 if (*s == ',')
257 s++;
258
259 /*
260 * Find the device from the BDF
261 */
262 cmdreg = read_pci_config(bus, slot, func, PCI_COMMAND);
263 classcode = read_pci_config(bus, slot, func, PCI_CLASS_REVISION);
264 bar0 = read_pci_config(bus, slot, func, PCI_BASE_ADDRESS_0);
265
266 /*
267 * Verify it is a 16550-UART type device
268 */
269 if (((classcode >> 16 != PCI_CLASS_COMMUNICATION_MODEM) &&
270 (classcode >> 16 != PCI_CLASS_COMMUNICATION_SERIAL)) ||
271 (((classcode >> 8) & 0xff) != PCI_SERIAL_16550_COMPATIBLE)) {
272 if (!force)
273 return;
274 }
275
276 /*
277 * Determine if it is IO or memory mapped
278 */
279 if ((bar0 & PCI_BASE_ADDRESS_SPACE) == PCI_BASE_ADDRESS_SPACE_IO) {
280 /* it is IO mapped */
281 serial_in = io_serial_in;
282 serial_out = io_serial_out;
283 early_serial_base = bar0 & PCI_BASE_ADDRESS_IO_MASK;
284 write_pci_config(bus, slot, func, PCI_COMMAND,
285 cmdreg|PCI_COMMAND_IO);
286 } else {
287 /* It is memory mapped - assume 32-bit alignment */
288 serial_in = mem32_serial_in;
289 serial_out = mem32_serial_out;
290 /* WARNING! assuming the address is always in the first 4G */
291 early_serial_base =
292 (unsigned long)early_ioremap(bar0 & PCI_BASE_ADDRESS_MEM_MASK, 0x10);
293 write_pci_config(bus, slot, func, PCI_COMMAND,
294 cmdreg|PCI_COMMAND_MEMORY);
295 }
296
297 /*
298 * Initialize the hardware
299 */
300 if (*s) {
301 if (strcmp(s, "nocfg") == 0)
302 /* Sometimes, we want to leave the UART alone
303 * and assume the BIOS has set it up correctly.
304 * "nocfg" tells us this is the case, and we
305 * should do no more setup.
306 */
307 return;
308 if (kstrtoul(s, 0, &baud) < 0 || baud == 0)
309 baud = DEFAULT_BAUD;
310 }
311
312 /* Convert from baud to divisor value */
313 divisor = 115200 / baud;
314
315 /* Set up the HW */
316 early_serial_hw_init(divisor);
317 }
318 #endif
319
320 static struct console early_serial_console = {
321 .name = "earlyser",
322 .write = early_serial_write,
323 .flags = CON_PRINTBUFFER,
324 .index = -1,
325 };
326
327 static void early_console_register(struct console *con, int keep_early)
328 {
329 if (con->index != -1) {
330 printk(KERN_CRIT "ERROR: earlyprintk= %s already used\n",
331 con->name);
332 return;
333 }
334 early_console = con;
335 if (keep_early)
336 early_console->flags &= ~CON_BOOT;
337 else
338 early_console->flags |= CON_BOOT;
339 register_console(early_console);
340 }
341
342 static int __init setup_early_printk(char *buf)
343 {
344 int keep;
345
346 if (!buf)
347 return 0;
348
349 if (early_console)
350 return 0;
351
352 keep = (strstr(buf, "keep") != NULL);
353
354 while (*buf != '\0') {
355 if (!strncmp(buf, "serial", 6)) {
356 buf += 6;
357 early_serial_init(buf);
358 early_console_register(&early_serial_console, keep);
359 if (!strncmp(buf, ",ttyS", 5))
360 buf += 5;
361 }
362 if (!strncmp(buf, "ttyS", 4)) {
363 early_serial_init(buf + 4);
364 early_console_register(&early_serial_console, keep);
365 }
366 #ifdef CONFIG_PCI
367 if (!strncmp(buf, "pciserial", 9)) {
368 early_pci_serial_init(buf + 9);
369 early_console_register(&early_serial_console, keep);
370 buf += 9; /* Keep from match the above "serial" */
371 }
372 #endif
373 if (!strncmp(buf, "vga", 3) &&
374 boot_params.screen_info.orig_video_isVGA == 1) {
375 max_xpos = boot_params.screen_info.orig_video_cols;
376 max_ypos = boot_params.screen_info.orig_video_lines;
377 current_ypos = boot_params.screen_info.orig_y;
378 early_console_register(&early_vga_console, keep);
379 }
380 #ifdef CONFIG_EARLY_PRINTK_DBGP
381 if (!strncmp(buf, "dbgp", 4) && !early_dbgp_init(buf + 4))
382 early_console_register(&early_dbgp_console, keep);
383 #endif
384 #ifdef CONFIG_HVC_XEN
385 if (!strncmp(buf, "xen", 3))
386 early_console_register(&xenboot_console, keep);
387 #endif
388 #ifdef CONFIG_EARLY_PRINTK_USB_XDBC
389 if (!strncmp(buf, "xdbc", 4))
390 early_xdbc_parse_parameter(buf + 4, keep);
391 #endif
392
393 buf++;
394 }
395 return 0;
396 }
397
398 early_param("earlyprintk", setup_early_printk);
399
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.