1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/console.h>
3 #include <linux/kernel.h>
4 #include <linux/kexec.h>
5 #include <linux/init.h>
6 #include <linux/string.h>
7 #include <linux/screen_info.h>
8 #include <linux/usb/ch9.h>
9 #include <linux/pci_regs.h>
10 #include <linux/pci_ids.h>
11 #include <linux/errno.h>
12 #include <linux/pgtable.h>
13 #include <asm/io.h>
14 #include <asm/processor.h>
15 #include <asm/fcntl.h>
16 #include <asm/setup.h>
17 #include <xen/hvc-console.h>
18 #include <asm/pci-direct.h>
19 #include <asm/fixmap.h>
20 #include <linux/usb/ehci_def.h>
21 #include <linux/usb/xhci-dbgp.h>
22 #include <asm/pci_x86.h>
23 #include <linux/static_call.h>
24
25 /* Simple VGA output */
26 #define VGABASE (__ISA_IO_base + 0xb8000)
27
28 static int max_ypos = 25, max_xpos = 80;
29 static int current_ypos = 25, current_xpos;
30
early_vga_write(struct console * con,const char * str,unsigned n)31 static void early_vga_write(struct console *con, const char *str, unsigned n)
32 {
33 char c;
34 int i, k, j;
35
36 while ((c = *str++) != '\0' && n-- > 0) {
37 if (current_ypos >= max_ypos) {
38 /* scroll 1 line up */
39 for (k = 1, j = 0; k < max_ypos; k++, j++) {
40 for (i = 0; i < max_xpos; i++) {
41 writew(readw(VGABASE+2*(max_xpos*k+i)),
42 VGABASE + 2*(max_xpos*j + i));
43 }
44 }
45 for (i = 0; i < max_xpos; i++)
46 writew(0x720, VGABASE + 2*(max_xpos*j + i));
47 current_ypos = max_ypos-1;
48 }
49 #ifdef CONFIG_KGDB_KDB
50 if (c == '\b') {
51 if (current_xpos > 0)
52 current_xpos--;
53 } else if (c == '\r') {
54 current_xpos = 0;
55 } else
56 #endif
57 if (c == '\n') {
58 current_xpos = 0;
59 current_ypos++;
60 } else if (c != '\r') {
61 writew(((0x7 << 8) | (unsigned short) c),
62 VGABASE + 2*(max_xpos*current_ypos +
63 current_xpos++));
64 if (current_xpos >= max_xpos) {
65 current_xpos = 0;
66 current_ypos++;
67 }
68 }
69 }
70 }
71
72 static struct console early_vga_console = {
73 .name = "earlyvga",
74 .write = early_vga_write,
75 .flags = CON_PRINTBUFFER,
76 .index = -1,
77 };
78
79 /* Serial functions loosely based on a similar package from Klaus P. Gerlicher */
80
81 static unsigned long early_serial_base = 0x3f8; /* ttyS0 */
82
83 #define XMTRDY 0x20
84
85 #define DLAB 0x80
86
87 #define TXR 0 /* Transmit register (WRITE) */
88 #define RXR 0 /* Receive register (READ) */
89 #define IER 1 /* Interrupt Enable */
90 #define IIR 2 /* Interrupt ID */
91 #define FCR 2 /* FIFO control */
92 #define LCR 3 /* Line control */
93 #define MCR 4 /* Modem control */
94 #define LSR 5 /* Line Status */
95 #define MSR 6 /* Modem Status */
96 #define DLL 0 /* Divisor Latch Low */
97 #define DLH 1 /* Divisor latch High */
98
io_serial_in(unsigned long addr,int offset)99 static __noendbr unsigned int io_serial_in(unsigned long addr, int offset)
100 {
101 return inb(addr + offset);
102 }
103 ANNOTATE_NOENDBR_SYM(io_serial_in);
104
io_serial_out(unsigned long addr,int offset,int value)105 static __noendbr void io_serial_out(unsigned long addr, int offset, int value)
106 {
107 outb(value, addr + offset);
108 }
109 ANNOTATE_NOENDBR_SYM(io_serial_out);
110
111 DEFINE_STATIC_CALL(serial_in, io_serial_in);
112 DEFINE_STATIC_CALL(serial_out, io_serial_out);
113
early_serial_putc(unsigned char ch)114 static int early_serial_putc(unsigned char ch)
115 {
116 unsigned timeout = 0xffff;
117
118 while ((static_call(serial_in)(early_serial_base, LSR) & XMTRDY) == 0 && --timeout)
119 cpu_relax();
120 static_call(serial_out)(early_serial_base, TXR, ch);
121 return timeout ? 0 : -1;
122 }
123
early_serial_write(struct console * con,const char * s,unsigned n)124 static void early_serial_write(struct console *con, const char *s, unsigned n)
125 {
126 while (*s && n-- > 0) {
127 if (*s == '\n')
128 early_serial_putc('\r');
129 early_serial_putc(*s);
130 s++;
131 }
132 }
133
early_serial_hw_init(unsigned divisor)134 static __init void early_serial_hw_init(unsigned divisor)
135 {
136 unsigned char c;
137
138 static_call(serial_out)(early_serial_base, LCR, 0x3); /* 8n1 */
139 static_call(serial_out)(early_serial_base, IER, 0); /* no interrupt */
140 static_call(serial_out)(early_serial_base, FCR, 0); /* no fifo */
141 static_call(serial_out)(early_serial_base, MCR, 0x3); /* DTR + RTS */
142
143 c = static_call(serial_in)(early_serial_base, LCR);
144 static_call(serial_out)(early_serial_base, LCR, c | DLAB);
145 static_call(serial_out)(early_serial_base, DLL, divisor & 0xff);
146 static_call(serial_out)(early_serial_base, DLH, (divisor >> 8) & 0xff);
147 static_call(serial_out)(early_serial_base, LCR, c & ~DLAB);
148
149 #if defined(CONFIG_KEXEC_CORE) && defined(CONFIG_X86_64)
150 if (static_call_query(serial_in) == io_serial_in)
151 kexec_debug_8250_port = early_serial_base;
152 #endif
153 }
154
155 #define DEFAULT_BAUD 9600
156
early_serial_init(char * s)157 static __init void early_serial_init(char *s)
158 {
159 unsigned divisor;
160 unsigned long baud = DEFAULT_BAUD;
161 char *e;
162
163 if (*s == ',')
164 ++s;
165
166 if (*s) {
167 unsigned port;
168 if (!strncmp(s, "0x", 2)) {
169 early_serial_base = simple_strtoul(s, &e, 16);
170 } else {
171 static const int __initconst bases[] = { 0x3f8, 0x2f8 };
172
173 if (!strncmp(s, "ttyS", 4))
174 s += 4;
175 port = simple_strtoul(s, &e, 10);
176 if (port > 1 || s == e)
177 port = 0;
178 early_serial_base = bases[port];
179 }
180 s += strcspn(s, ",");
181 if (*s == ',')
182 s++;
183 }
184
185 if (*s) {
186 baud = simple_strtoull(s, &e, 0);
187
188 if (baud == 0 || s == e)
189 baud = DEFAULT_BAUD;
190 }
191
192 /* Convert from baud to divisor value */
193 divisor = 115200 / baud;
194
195 /* Set up the HW */
196 early_serial_hw_init(divisor);
197 }
198
mem32_serial_out(unsigned long addr,int offset,int value)199 static __noendbr void mem32_serial_out(unsigned long addr, int offset, int value)
200 {
201 u32 __iomem *vaddr = (u32 __iomem *)addr;
202 /* shift implied by pointer type */
203 writel(value, vaddr + offset);
204 }
205 ANNOTATE_NOENDBR_SYM(mem32_serial_out);
206
mem32_serial_in(unsigned long addr,int offset)207 static __noendbr unsigned int mem32_serial_in(unsigned long addr, int offset)
208 {
209 u32 __iomem *vaddr = (u32 __iomem *)addr;
210 /* shift implied by pointer type */
211 return readl(vaddr + offset);
212 }
213 ANNOTATE_NOENDBR_SYM(mem32_serial_in);
214
215 /*
216 * early_mmio_serial_init() - Initialize MMIO-based early serial console.
217 * @s: MMIO-based serial specification.
218 */
early_mmio_serial_init(char * s)219 static __init void early_mmio_serial_init(char *s)
220 {
221 unsigned long baudrate;
222 unsigned long membase;
223 char *e;
224
225 if (*s == ',')
226 s++;
227
228 if (!strncmp(s, "0x", 2)) {
229 /* NB: only 32-bit addresses are supported. */
230 membase = simple_strtoul(s, &e, 16);
231 early_serial_base = (unsigned long)early_ioremap(membase, PAGE_SIZE);
232
233 static_call_update(serial_in, mem32_serial_in);
234 static_call_update(serial_out, mem32_serial_out);
235
236 s += strcspn(s, ",");
237 if (*s == ',')
238 s++;
239 }
240
241 if (!strncmp(s, "nocfg", 5)) {
242 baudrate = 0;
243 } else {
244 baudrate = simple_strtoul(s, &e, 0);
245 if (baudrate == 0 || s == e)
246 baudrate = DEFAULT_BAUD;
247 }
248
249 if (baudrate)
250 early_serial_hw_init(115200 / baudrate);
251 }
252
253 #ifdef CONFIG_PCI
254 /*
255 * early_pci_serial_init()
256 *
257 * This function is invoked when the early_printk param starts with "pciserial"
258 * The rest of the param should be "[force],B:D.F,baud", where B, D & F describe
259 * the location of a PCI device that must be a UART device. "force" is optional
260 * and overrides the use of an UART device with a wrong PCI class code.
261 */
early_pci_serial_init(char * s)262 static __init void early_pci_serial_init(char *s)
263 {
264 unsigned divisor;
265 unsigned long baud = DEFAULT_BAUD;
266 u8 bus, slot, func;
267 u32 classcode, bar0;
268 u16 cmdreg;
269 char *e;
270 int force = 0;
271
272 if (*s == ',')
273 ++s;
274
275 if (*s == 0)
276 return;
277
278 /* Force the use of an UART device with wrong class code */
279 if (!strncmp(s, "force,", 6)) {
280 force = 1;
281 s += 6;
282 }
283
284 /*
285 * Part the param to get the BDF values
286 */
287 bus = (u8)simple_strtoul(s, &e, 16);
288 s = e;
289 if (*s != ':')
290 return;
291 ++s;
292 slot = (u8)simple_strtoul(s, &e, 16);
293 s = e;
294 if (*s != '.')
295 return;
296 ++s;
297 func = (u8)simple_strtoul(s, &e, 16);
298 s = e;
299
300 /* A baud might be following */
301 if (*s == ',')
302 s++;
303
304 /*
305 * Find the device from the BDF
306 */
307 cmdreg = read_pci_config(bus, slot, func, PCI_COMMAND);
308 classcode = read_pci_config(bus, slot, func, PCI_CLASS_REVISION);
309 bar0 = read_pci_config(bus, slot, func, PCI_BASE_ADDRESS_0);
310
311 /*
312 * Verify it is a 16550-UART type device
313 */
314 if (((classcode >> 16 != PCI_CLASS_COMMUNICATION_MODEM) &&
315 (classcode >> 16 != PCI_CLASS_COMMUNICATION_SERIAL)) ||
316 (((classcode >> 8) & 0xff) != PCI_SERIAL_16550_COMPATIBLE)) {
317 if (!force)
318 return;
319 }
320
321 /*
322 * Determine if it is IO or memory mapped
323 */
324 if ((bar0 & PCI_BASE_ADDRESS_SPACE) == PCI_BASE_ADDRESS_SPACE_IO) {
325 /* it is IO mapped */
326 early_serial_base = bar0 & PCI_BASE_ADDRESS_IO_MASK;
327 write_pci_config(bus, slot, func, PCI_COMMAND,
328 cmdreg|PCI_COMMAND_IO);
329 } else {
330 /* It is memory mapped - assume 32-bit alignment */
331 static_call_update(serial_in, mem32_serial_in);
332 static_call_update(serial_out, mem32_serial_out);
333 /* WARNING! assuming the address is always in the first 4G */
334 early_serial_base =
335 (unsigned long)early_ioremap(bar0 & PCI_BASE_ADDRESS_MEM_MASK, 0x10);
336 #if defined(CONFIG_KEXEC_CORE) && defined(CONFIG_X86_64)
337 kexec_debug_8250_mmio32 = bar0 & PCI_BASE_ADDRESS_MEM_MASK;
338 #endif
339 write_pci_config(bus, slot, func, PCI_COMMAND,
340 cmdreg|PCI_COMMAND_MEMORY);
341 }
342
343 /*
344 * Initialize the hardware
345 */
346 if (*s) {
347 if (strcmp(s, "nocfg") == 0)
348 /* Sometimes, we want to leave the UART alone
349 * and assume the BIOS has set it up correctly.
350 * "nocfg" tells us this is the case, and we
351 * should do no more setup.
352 */
353 return;
354 if (kstrtoul(s, 0, &baud) < 0 || baud == 0)
355 baud = DEFAULT_BAUD;
356 }
357
358 /* Convert from baud to divisor value */
359 divisor = 115200 / baud;
360
361 /* Set up the HW */
362 early_serial_hw_init(divisor);
363 }
364 #endif
365
366 static struct console early_serial_console = {
367 .name = "earlyser",
368 .write = early_serial_write,
369 .flags = CON_PRINTBUFFER,
370 .index = -1,
371 };
372
early_console_register(struct console * con,int keep_early)373 static void early_console_register(struct console *con, int keep_early)
374 {
375 if (con->index != -1) {
376 printk(KERN_CRIT "ERROR: earlyprintk= %s already used\n",
377 con->name);
378 return;
379 }
380 early_console = con;
381 if (keep_early)
382 early_console->flags &= ~CON_BOOT;
383 else
384 early_console->flags |= CON_BOOT;
385 register_console(early_console);
386 }
387
setup_early_printk(char * buf)388 static int __init setup_early_printk(char *buf)
389 {
390 int keep;
391
392 if (!buf)
393 return 0;
394
395 if (early_console)
396 return 0;
397
398 keep = (strstr(buf, "keep") != NULL);
399
400 while (*buf != '\0') {
401 if (!strncmp(buf, "mmio32", 6)) {
402 buf += 6;
403 early_mmio_serial_init(buf);
404 early_console_register(&early_serial_console, keep);
405 }
406 if (!strncmp(buf, "serial", 6)) {
407 buf += 6;
408 early_serial_init(buf);
409 early_console_register(&early_serial_console, keep);
410 if (!strncmp(buf, ",ttyS", 5))
411 buf += 5;
412 }
413 if (!strncmp(buf, "ttyS", 4)) {
414 early_serial_init(buf + 4);
415 early_console_register(&early_serial_console, keep);
416 }
417 #ifdef CONFIG_PCI
418 if (!strncmp(buf, "pciserial", 9)) {
419 buf += 9; /* Keep from match the above "pciserial" */
420 early_pci_serial_init(buf);
421 early_console_register(&early_serial_console, keep);
422 }
423 #endif
424 if (!strncmp(buf, "vga", 3) &&
425 boot_params.screen_info.orig_video_isVGA == 1) {
426 max_xpos = boot_params.screen_info.orig_video_cols;
427 max_ypos = boot_params.screen_info.orig_video_lines;
428 current_ypos = boot_params.screen_info.orig_y;
429 early_console_register(&early_vga_console, keep);
430 }
431 #ifdef CONFIG_EARLY_PRINTK_DBGP
432 if (!strncmp(buf, "dbgp", 4) && !early_dbgp_init(buf + 4))
433 early_console_register(&early_dbgp_console, keep);
434 #endif
435 #ifdef CONFIG_HVC_XEN
436 if (!strncmp(buf, "xen", 3))
437 early_console_register(&xenboot_console, keep);
438 #endif
439 #ifdef CONFIG_EARLY_PRINTK_USB_XDBC
440 if (!strncmp(buf, "xdbc", 4))
441 early_xdbc_parse_parameter(buf + 4, keep);
442 #endif
443
444 buf++;
445 }
446 return 0;
447 }
448
449 early_param("earlyprintk", setup_early_printk);
450