~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/arch/x86/kernel/early_printk.c

Version: ~ [ linux-4.20-rc6 ] ~ [ linux-4.19.8 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.87 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.144 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.166 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.128 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.61 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.39.4 ] ~ [ linux-2.6.38.8 ] ~ [ linux-2.6.37.6 ] ~ [ linux-2.6.36.4 ] ~ [ linux-2.6.35.14 ] ~ [ linux-2.6.34.15 ] ~ [ linux-2.6.33.20 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.31.14 ] ~ [ linux-2.6.30.10 ] ~ [ linux-2.6.29.6 ] ~ [ linux-2.6.28.10 ] ~ [ linux-2.6.27.62 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  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 <asm/io.h>
 12 #include <asm/processor.h>
 13 #include <asm/fcntl.h>
 14 #include <asm/setup.h>
 15 #include <xen/hvc-console.h>
 16 #include <asm/pci-direct.h>
 17 #include <asm/fixmap.h>
 18 #include <asm/intel-mid.h>
 19 #include <asm/pgtable.h>
 20 #include <linux/usb/ehci_def.h>
 21 #include <linux/usb/xhci-dbgp.h>
 22 #include <linux/efi.h>
 23 #include <asm/efi.h>
 24 #include <asm/pci_x86.h>
 25 
 26 /* Simple VGA output */
 27 #define VGABASE         (__ISA_IO_base + 0xb8000)
 28 
 29 static int max_ypos = 25, max_xpos = 80;
 30 static int current_ypos = 25, current_xpos;
 31 
 32 static void early_vga_write(struct console *con, const char *str, unsigned n)
 33 {
 34         char c;
 35         int  i, k, j;
 36 
 37         while ((c = *str++) != '\0' && n-- > 0) {
 38                 if (current_ypos >= max_ypos) {
 39                         /* scroll 1 line up */
 40                         for (k = 1, j = 0; k < max_ypos; k++, j++) {
 41                                 for (i = 0; i < max_xpos; i++) {
 42                                         writew(readw(VGABASE+2*(max_xpos*k+i)),
 43                                                VGABASE + 2*(max_xpos*j + i));
 44                                 }
 45                         }
 46                         for (i = 0; i < max_xpos; i++)
 47                                 writew(0x720, VGABASE + 2*(max_xpos*j + i));
 48                         current_ypos = max_ypos-1;
 49                 }
 50 #ifdef CONFIG_KGDB_KDB
 51                 if (c == '\b') {
 52                         if (current_xpos > 0)
 53                                 current_xpos--;
 54                 } else if (c == '\r') {
 55                         current_xpos = 0;
 56                 } else
 57 #endif
 58                 if (c == '\n') {
 59                         current_xpos = 0;
 60                         current_ypos++;
 61                 } else if (c != '\r')  {
 62                         writew(((0x7 << 8) | (unsigned short) c),
 63                                VGABASE + 2*(max_xpos*current_ypos +
 64                                                 current_xpos++));
 65                         if (current_xpos >= max_xpos) {
 66                                 current_xpos = 0;
 67                                 current_ypos++;
 68                         }
 69                 }
 70         }
 71 }
 72 
 73 static struct console early_vga_console = {
 74         .name =         "earlyvga",
 75         .write =        early_vga_write,
 76         .flags =        CON_PRINTBUFFER,
 77         .index =        -1,
 78 };
 79 
 80 /* Serial functions loosely based on a similar package from Klaus P. Gerlicher */
 81 
 82 static unsigned long early_serial_base = 0x3f8;  /* ttyS0 */
 83 
 84 #define XMTRDY          0x20
 85 
 86 #define DLAB            0x80
 87 
 88 #define TXR             0       /*  Transmit register (WRITE) */
 89 #define RXR             0       /*  Receive register  (READ)  */
 90 #define IER             1       /*  Interrupt Enable          */
 91 #define IIR             2       /*  Interrupt ID              */
 92 #define FCR             2       /*  FIFO control              */
 93 #define LCR             3       /*  Line control              */
 94 #define MCR             4       /*  Modem control             */
 95 #define LSR             5       /*  Line Status               */
 96 #define MSR             6       /*  Modem Status              */
 97 #define DLL             0       /*  Divisor Latch Low         */
 98 #define DLH             1       /*  Divisor latch High        */
 99 
100 static unsigned int io_serial_in(unsigned long addr, int offset)
101 {
102         return inb(addr + offset);
103 }
104 
105 static void io_serial_out(unsigned long addr, int offset, int value)
106 {
107         outb(value, addr + offset);
108 }
109 
110 static unsigned int (*serial_in)(unsigned long addr, int offset) = io_serial_in;
111 static void (*serial_out)(unsigned long addr, int offset, int value) = io_serial_out;
112 
113 static int early_serial_putc(unsigned char ch)
114 {
115         unsigned timeout = 0xffff;
116 
117         while ((serial_in(early_serial_base, LSR) & XMTRDY) == 0 && --timeout)
118                 cpu_relax();
119         serial_out(early_serial_base, TXR, ch);
120         return timeout ? 0 : -1;
121 }
122 
123 static void early_serial_write(struct console *con, const char *s, unsigned n)
124 {
125         while (*s && n-- > 0) {
126                 if (*s == '\n')
127                         early_serial_putc('\r');
128                 early_serial_putc(*s);
129                 s++;
130         }
131 }
132 
133 static __init void early_serial_hw_init(unsigned divisor)
134 {
135         unsigned char c;
136 
137         serial_out(early_serial_base, LCR, 0x3);        /* 8n1 */
138         serial_out(early_serial_base, IER, 0);  /* no interrupt */
139         serial_out(early_serial_base, FCR, 0);  /* no fifo */
140         serial_out(early_serial_base, MCR, 0x3);        /* DTR + RTS */
141 
142         c = serial_in(early_serial_base, LCR);
143         serial_out(early_serial_base, LCR, c | DLAB);
144         serial_out(early_serial_base, DLL, divisor & 0xff);
145         serial_out(early_serial_base, DLH, (divisor >> 8) & 0xff);
146         serial_out(early_serial_base, LCR, c & ~DLAB);
147 }
148 
149 #define DEFAULT_BAUD 9600
150 
151 static __init void early_serial_init(char *s)
152 {
153         unsigned divisor;
154         unsigned long baud = DEFAULT_BAUD;
155         char *e;
156 
157         if (*s == ',')
158                 ++s;
159 
160         if (*s) {
161                 unsigned port;
162                 if (!strncmp(s, "0x", 2)) {
163                         early_serial_base = simple_strtoul(s, &e, 16);
164                 } else {
165                         static const int __initconst bases[] = { 0x3f8, 0x2f8 };
166 
167                         if (!strncmp(s, "ttyS", 4))
168                                 s += 4;
169                         port = simple_strtoul(s, &e, 10);
170                         if (port > 1 || s == e)
171                                 port = 0;
172                         early_serial_base = bases[port];
173                 }
174                 s += strcspn(s, ",");
175                 if (*s == ',')
176                         s++;
177         }
178 
179         if (*s) {
180                 baud = simple_strtoull(s, &e, 0);
181 
182                 if (baud == 0 || s == e)
183                         baud = DEFAULT_BAUD;
184         }
185 
186         /* Convert from baud to divisor value */
187         divisor = 115200 / baud;
188 
189         /* These will always be IO based ports */
190         serial_in = io_serial_in;
191         serial_out = io_serial_out;
192 
193         /* Set up the HW */
194         early_serial_hw_init(divisor);
195 }
196 
197 #ifdef CONFIG_PCI
198 static void mem32_serial_out(unsigned long addr, int offset, int value)
199 {
200         u32 __iomem *vaddr = (u32 __iomem *)addr;
201         /* shift implied by pointer type */
202         writel(value, vaddr + offset);
203 }
204 
205 static unsigned int mem32_serial_in(unsigned long addr, int offset)
206 {
207         u32 __iomem *vaddr = (u32 __iomem *)addr;
208         /* shift implied by pointer type */
209         return readl(vaddr + offset);
210 }
211 
212 /*
213  * early_pci_serial_init()
214  *
215  * This function is invoked when the early_printk param starts with "pciserial"
216  * The rest of the param should be "[force],B:D.F,baud", where B, D & F describe
217  * the location of a PCI device that must be a UART device. "force" is optional
218  * and overrides the use of an UART device with a wrong PCI class code.
219  */
220 static __init void early_pci_serial_init(char *s)
221 {
222         unsigned divisor;
223         unsigned long baud = DEFAULT_BAUD;
224         u8 bus, slot, func;
225         u32 classcode, bar0;
226         u16 cmdreg;
227         char *e;
228         int force = 0;
229 
230         if (*s == ',')
231                 ++s;
232 
233         if (*s == 0)
234                 return;
235 
236         /* Force the use of an UART device with wrong class code */
237         if (!strncmp(s, "force,", 6)) {
238                 force = 1;
239                 s += 6;
240         }
241 
242         /*
243          * Part the param to get the BDF values
244          */
245         bus = (u8)simple_strtoul(s, &e, 16);
246         s = e;
247         if (*s != ':')
248                 return;
249         ++s;
250         slot = (u8)simple_strtoul(s, &e, 16);
251         s = e;
252         if (*s != '.')
253                 return;
254         ++s;
255         func = (u8)simple_strtoul(s, &e, 16);
256         s = e;
257 
258         /* A baud might be following */
259         if (*s == ',')
260                 s++;
261 
262         /*
263          * Find the device from the BDF
264          */
265         cmdreg = read_pci_config(bus, slot, func, PCI_COMMAND);
266         classcode = read_pci_config(bus, slot, func, PCI_CLASS_REVISION);
267         bar0 = read_pci_config(bus, slot, func, PCI_BASE_ADDRESS_0);
268 
269         /*
270          * Verify it is a UART type device
271          */
272         if (((classcode >> 16 != PCI_CLASS_COMMUNICATION_MODEM) &&
273              (classcode >> 16 != PCI_CLASS_COMMUNICATION_SERIAL)) ||
274            (((classcode >> 8) & 0xff) != 0x02)) /* 16550 I/F at BAR0 */ {
275                 if (!force)
276                         return;
277         }
278 
279         /*
280          * Determine if it is IO or memory mapped
281          */
282         if (bar0 & 0x01) {
283                 /* it is IO mapped */
284                 serial_in = io_serial_in;
285                 serial_out = io_serial_out;
286                 early_serial_base = bar0&0xfffffffc;
287                 write_pci_config(bus, slot, func, PCI_COMMAND,
288                                                 cmdreg|PCI_COMMAND_IO);
289         } else {
290                 /* It is memory mapped - assume 32-bit alignment */
291                 serial_in = mem32_serial_in;
292                 serial_out = mem32_serial_out;
293                 /* WARNING! assuming the address is always in the first 4G */
294                 early_serial_base =
295                         (unsigned long)early_ioremap(bar0 & 0xfffffff0, 0x10);
296                 write_pci_config(bus, slot, func, PCI_COMMAND,
297                                                 cmdreg|PCI_COMMAND_MEMORY);
298         }
299 
300         /*
301          * Initialize the hardware
302          */
303         if (*s) {
304                 if (strcmp(s, "nocfg") == 0)
305                         /* Sometimes, we want to leave the UART alone
306                          * and assume the BIOS has set it up correctly.
307                          * "nocfg" tells us this is the case, and we
308                          * should do no more setup.
309                          */
310                         return;
311                 if (kstrtoul(s, 0, &baud) < 0 || baud == 0)
312                         baud = DEFAULT_BAUD;
313         }
314 
315         /* Convert from baud to divisor value */
316         divisor = 115200 / baud;
317 
318         /* Set up the HW */
319         early_serial_hw_init(divisor);
320 }
321 #endif
322 
323 static struct console early_serial_console = {
324         .name =         "earlyser",
325         .write =        early_serial_write,
326         .flags =        CON_PRINTBUFFER,
327         .index =        -1,
328 };
329 
330 static void early_console_register(struct console *con, int keep_early)
331 {
332         if (con->index != -1) {
333                 printk(KERN_CRIT "ERROR: earlyprintk= %s already used\n",
334                        con->name);
335                 return;
336         }
337         early_console = con;
338         if (keep_early)
339                 early_console->flags &= ~CON_BOOT;
340         else
341                 early_console->flags |= CON_BOOT;
342         register_console(early_console);
343 }
344 
345 static int __init setup_early_printk(char *buf)
346 {
347         int keep;
348 
349         if (!buf)
350                 return 0;
351 
352         if (early_console)
353                 return 0;
354 
355         keep = (strstr(buf, "keep") != NULL);
356 
357         while (*buf != '\0') {
358                 if (!strncmp(buf, "serial", 6)) {
359                         buf += 6;
360                         early_serial_init(buf);
361                         early_console_register(&early_serial_console, keep);
362                         if (!strncmp(buf, ",ttyS", 5))
363                                 buf += 5;
364                 }
365                 if (!strncmp(buf, "ttyS", 4)) {
366                         early_serial_init(buf + 4);
367                         early_console_register(&early_serial_console, keep);
368                 }
369 #ifdef CONFIG_PCI
370                 if (!strncmp(buf, "pciserial", 9)) {
371                         early_pci_serial_init(buf + 9);
372                         early_console_register(&early_serial_console, keep);
373                         buf += 9; /* Keep from match the above "serial" */
374                 }
375 #endif
376                 if (!strncmp(buf, "vga", 3) &&
377                     boot_params.screen_info.orig_video_isVGA == 1) {
378                         max_xpos = boot_params.screen_info.orig_video_cols;
379                         max_ypos = boot_params.screen_info.orig_video_lines;
380                         current_ypos = boot_params.screen_info.orig_y;
381                         early_console_register(&early_vga_console, keep);
382                 }
383 #ifdef CONFIG_EARLY_PRINTK_DBGP
384                 if (!strncmp(buf, "dbgp", 4) && !early_dbgp_init(buf + 4))
385                         early_console_register(&early_dbgp_console, keep);
386 #endif
387 #ifdef CONFIG_HVC_XEN
388                 if (!strncmp(buf, "xen", 3))
389                         early_console_register(&xenboot_console, keep);
390 #endif
391 #ifdef CONFIG_EARLY_PRINTK_EFI
392                 if (!strncmp(buf, "efi", 3))
393                         early_console_register(&early_efi_console, keep);
394 #endif
395 #ifdef CONFIG_EARLY_PRINTK_USB_XDBC
396                 if (!strncmp(buf, "xdbc", 4))
397                         early_xdbc_parse_parameter(buf + 4);
398 #endif
399 
400                 buf++;
401         }
402         return 0;
403 }
404 
405 early_param("earlyprintk", setup_early_printk);
406 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp