kernel/arch/x86/kernel/early_printk.c

   1 #include <linux/console.h>
   2 #include <linux/kernel.h>
   3 #include <linux/init.h>
   4 #include <linux/string.h>
   5 #include <linux/screen_info.h>
   6 #include <linux/usb/ch9.h>
   7 #include <linux/pci_regs.h>
   8 #include <linux/pci_ids.h>
   9 #include <linux/errno.h>
  10 #include <asm/io.h>
  11 #include <asm/processor.h>
  12 #include <asm/fcntl.h>
  13 #include <asm/setup.h>
  14 #include <xen/hvc-console.h>
  15 #include <asm/pci-direct.h>
  16 #include <asm/fixmap.h>
  17 #include <asm/intel-mid.h>
  18 #include <asm/pgtable.h>
  19 #include <linux/usb/ehci_def.h>
  20 #include <linux/efi.h>
  21 #include <asm/efi.h>
  22 #include <asm/pci_x86.h>
  23
  24 /* Simple VGA output */
  25 #define VGABASE         (__ISA_IO_base + 0xb8000)
  26
  27 static int max_ypos = 25, max_xpos = 80;
  28 static int current_ypos = 25, current_xpos;
  29
  30 static void early_vga_write(struct console *con, const char *str, unsigned n)
  31 {
  32         char c;
  33         int  i, k, j;
  34
  35         while ((c = *str++) != '\0' && n-- > 0) {
  36                 if (current_ypos >= max_ypos) {
  37                         /* scroll 1 line up */
  38                         for (k = 1, j = 0; k < max_ypos; k++, j++) {
  39                                 for (i = 0; i < max_xpos; i++) {
  40                                         writew(readw(VGABASE+2*(max_xpos*k+i)),
  41                                                VGABASE + 2*(max_xpos*j + i));
  42                                 }
  43                         }
  44                         for (i = 0; i < max_xpos; i++)
  45                                 writew(0x720, VGABASE + 2*(max_xpos*j + i));
  46                         current_ypos = max_ypos-1;
  47                 }
  48 #ifdef CONFIG_KGDB_KDB
  49                 if (c == '\b') {
  50                         if (current_xpos > 0)
  51                                 current_xpos--;
  52                 } else if (c == '\r') {
  53                         current_xpos = 0;
  54                 } else
  55 #endif
  56                 if (c == '\n') {
  57                         current_xpos = 0;
  58                         current_ypos++;
  59                 } else if (c != '\r')  {
  60                         writew(((0x7 << 8) | (unsigned short) c),
  61                                VGABASE + 2*(max_xpos*current_ypos +
  62                                                 current_xpos++));
  63                         if (current_xpos >= max_xpos) {
  64                                 current_xpos = 0;
  65                                 current_ypos++;
  66                         }
  67                 }
  68         }
  69 }
  70
  71 static struct console early_vga_console = {
  72         .name =         "earlyvga",
  73         .write =        early_vga_write,
  74         .flags =        CON_PRINTBUFFER,
  75         .index =        -1,
  76 };
  77
  78 /* Serial functions loosely based on a similar package from Klaus P. Gerlicher */
  79
  80 static unsigned long early_serial_base = 0x3f8;  /* ttyS0 */
  81
  82 #define XMTRDY          0x20
  83
  84 #define DLAB            0x80
  85
  86 #define TXR             0       /*  Transmit register (WRITE) */
  87 #define RXR             0       /*  Receive register  (READ)  */
  88 #define IER             1       /*  Interrupt Enable          */
  89 #define IIR             2       /*  Interrupt ID              */
  90 #define FCR             2       /*  FIFO control              */
  91 #define LCR             3       /*  Line control              */
  92 #define MCR             4       /*  Modem control             */
  93 #define LSR             5       /*  Line Status               */
  94 #define MSR             6       /*  Modem Status              */
  95 #define DLL             0       /*  Divisor Latch Low         */
  96 #define DLH             1       /*  Divisor latch High        */
  97
  98 static unsigned int io_serial_in(unsigned long addr, int offset)
  99 {
 100         return inb(addr + offset);
 101 }
 102
 103 static void io_serial_out(unsigned long addr, int offset, int value)
 104 {
 105         outb(value, addr + offset);
 106 }
 107
 108 static unsigned int (*serial_in)(unsigned long addr, int offset) = io_serial_in;
 109 static void (*serial_out)(unsigned long addr, int offset, int value) = io_serial_out;
 110
 111 static int early_serial_putc(unsigned char ch)
 112 {
 113         unsigned timeout = 0xffff;
 114
 115         while ((serial_in(early_serial_base, LSR) & XMTRDY) == 0 && --timeout)
 116                 cpu_relax();
 117         serial_out(early_serial_base, TXR, ch);
 118         return timeout ? 0 : -1;
 119 }
 120
 121 static void early_serial_write(struct console *con, const char *s, unsigned n)
 122 {
 123         while (*s && n-- > 0) {
 124                 if (*s == '\n')
 125                         early_serial_putc('\r');
 126                 early_serial_putc(*s);
 127                 s++;
 128         }
 129 }
 130
 131 static __init void early_serial_hw_init(unsigned divisor)
 132 {
 133         unsigned char c;
 134
 135         serial_out(early_serial_base, LCR, 0x3);        /* 8n1 */
 136         serial_out(early_serial_base, IER, 0);  /* no interrupt */
 137         serial_out(early_serial_base, FCR, 0);  /* no fifo */
 138         serial_out(early_serial_base, MCR, 0x3);        /* DTR + RTS */
 139
 140         c = serial_in(early_serial_base, LCR);
 141         serial_out(early_serial_base, LCR, c | DLAB);
 142         serial_out(early_serial_base, DLL, divisor & 0xff);
 143         serial_out(early_serial_base, DLH, (divisor >> 8) & 0xff);
 144         serial_out(early_serial_base, LCR, c & ~DLAB);
 145 }
 146
 147 #define DEFAULT_BAUD 9600
 148
 149 static __init void early_serial_init(char *s)
 150 {
 151         unsigned divisor;
 152         unsigned long baud = DEFAULT_BAUD;
 153         char *e;
 154
 155         if (*s == ',')
 156                 ++s;
 157
 158         if (*s) {
 159                 unsigned port;
 160                 if (!strncmp(s, "0x", 2)) {
 161                         early_serial_base = simple_strtoul(s, &e, 16);
 162                 } else {
 163                         static const int __initconst bases[] = { 0x3f8, 0x2f8 };
 164
 165                         if (!strncmp(s, "ttyS", 4))
 166                                 s += 4;
 167                         port = simple_strtoul(s, &e, 10);
 168                         if (port > 1 || s == e)
 169                                 port = 0;
 170                         early_serial_base = bases[port];
 171                 }
 172                 s += strcspn(s, ",");
 173                 if (*s == ',')
 174                         s++;
 175         }
 176
 177         if (*s) {
 178                 if (kstrtoul(s, 0, &baud) < 0 || baud == 0)
 179                         baud = DEFAULT_BAUD;
 180         }
 181
 182         /* Convert from baud to divisor value */
 183         divisor = 115200 / baud;
 184
 185         /* These will always be IO based ports */
 186         serial_in = io_serial_in;
 187         serial_out = io_serial_out;
 188
 189         /* Set up the HW */
 190         early_serial_hw_init(divisor);
 191 }
 192
 193 #ifdef CONFIG_PCI
 194 static void mem32_serial_out(unsigned long addr, int offset, int value)
 195 {
 196         u32 *vaddr = (u32 *)addr;
 197         /* shift implied by pointer type */
 198         writel(value, vaddr + offset);
 199 }
 200
 201 static unsigned int mem32_serial_in(unsigned long addr, int offset)
 202 {
 203         u32 *vaddr = (u32 *)addr;
 204         /* shift implied by pointer type */
 205         return readl(vaddr + offset);
 206 }
 207
 208 /*
 209  * early_pci_serial_init()
 210  *
 211  * This function is invoked when the early_printk param starts with "pciserial"
 212  * The rest of the param should be ",B:D.F,baud" where B, D & F describe the
 213  * location of a PCI device that must be a UART device.
 214  */
 215 static __init void early_pci_serial_init(char *s)
 216 {
 217         unsigned divisor;
 218         unsigned long baud = DEFAULT_BAUD;
 219         u8 bus, slot, func;
 220         u32 classcode, bar0;
 221         u16 cmdreg;
 222         char *e;
 223
 224
 225         /*
 226          * First, part the param to get the BDF values
 227          */
 228         if (*s == ',')
 229                 ++s;
 230
 231         if (*s == 0)
 232                 return;
 233
 234         bus = (u8)simple_strtoul(s, &e, 16);
 235         s = e;
 236         if (*s != ':')
 237                 return;
 238         ++s;
 239         slot = (u8)simple_strtoul(s, &e, 16);
 240         s = e;
 241         if (*s != '.')
 242                 return;
 243         ++s;
 244         func = (u8)simple_strtoul(s, &e, 16);
 245         s = e;
 246
 247         /* A baud might be following */
 248         if (*s == ',')
 249                 s++;
 250
 251         /*
 252          * Second, find the device from the BDF
 253          */
 254         cmdreg = read_pci_config(bus, slot, func, PCI_COMMAND);
 255         classcode = read_pci_config(bus, slot, func, PCI_CLASS_REVISION);
 256         bar0 = read_pci_config(bus, slot, func, PCI_BASE_ADDRESS_0);
 257
 258         /*
 259          * Verify it is a UART type device
 260          */
 261         if (((classcode >> 16 != PCI_CLASS_COMMUNICATION_MODEM) &&
 262              (classcode >> 16 != PCI_CLASS_COMMUNICATION_SERIAL)) ||
 263            (((classcode >> 8) & 0xff) != 0x02)) /* 16550 I/F at BAR0 */
 264                 return;
 265
 266         /*
 267          * Determine if it is IO or memory mapped
 268          */
 269         if (bar0 & 0x01) {
 270                 /* it is IO mapped */
 271                 serial_in = io_serial_in;
 272                 serial_out = io_serial_out;
 273                 early_serial_base = bar0&0xfffffffc;
 274                 write_pci_config(bus, slot, func, PCI_COMMAND,
 275                                                 cmdreg|PCI_COMMAND_IO);
 276         } else {
 277                 /* It is memory mapped - assume 32-bit alignment */
 278                 serial_in = mem32_serial_in;
 279                 serial_out = mem32_serial_out;
 280                 /* WARNING! assuming the address is always in the first 4G */
 281                 early_serial_base =
 282                         (unsigned long)early_ioremap(bar0 & 0xfffffff0, 0x10);
 283                 write_pci_config(bus, slot, func, PCI_COMMAND,
 284                                                 cmdreg|PCI_COMMAND_MEMORY);
 285         }
 286
 287         /*
 288          * Lastly, initalize the hardware
 289          */
 290         if (*s) {
 291                 if (strcmp(s, "nocfg") == 0)
 292                         /* Sometimes, we want to leave the UART alone
 293                          * and assume the BIOS has set it up correctly.
 294                          * "nocfg" tells us this is the case, and we
 295                          * should do no more setup.
 296                          */
 297                         return;
 298                 if (kstrtoul(s, 0, &baud) < 0 || baud == 0)
 299                         baud = DEFAULT_BAUD;
 300         }
 301
 302         /* Convert from baud to divisor value */
 303         divisor = 115200 / baud;
 304
 305         /* Set up the HW */
 306         early_serial_hw_init(divisor);
 307 }
 308 #endif
 309
 310 static struct console early_serial_console = {
 311         .name =         "earlyser",
 312         .write =        early_serial_write,
 313         .flags =        CON_PRINTBUFFER,
 314         .index =        -1,
 315 };
 316
 317 static inline void early_console_register(struct console *con, int keep_early)
 318 {
 319         if (con->index != -1) {
 320                 printk(KERN_CRIT "ERROR: earlyprintk= %s already used\n",
 321                        con->name);
 322                 return;
 323         }
 324         early_console = con;
 325         if (keep_early)
 326                 early_console->flags &= ~CON_BOOT;
 327         else
 328                 early_console->flags |= CON_BOOT;
 329         register_console(early_console);
 330 }
 331
 332 static int __init setup_early_printk(char *buf)
 333 {
 334         int keep;
 335
 336         if (!buf)
 337                 return 0;
 338
 339         if (early_console)
 340                 return 0;
 341
 342         keep = (strstr(buf, "keep") != NULL);
 343
 344         while (*buf != '\0') {
 345                 if (!strncmp(buf, "serial", 6)) {
 346                         buf += 6;
 347                         early_serial_init(buf);
 348                         early_console_register(&early_serial_console, keep);
 349                         if (!strncmp(buf, ",ttyS", 5))
 350                                 buf += 5;
 351                 }
 352                 if (!strncmp(buf, "ttyS", 4)) {
 353                         early_serial_init(buf + 4);
 354                         early_console_register(&early_serial_console, keep);
 355                 }
 356 #ifdef CONFIG_PCI
 357                 if (!strncmp(buf, "pciserial", 9)) {
 358                         early_pci_serial_init(buf + 9);
 359                         early_console_register(&early_serial_console, keep);
 360                         buf += 9; /* Keep from match the above "serial" */
 361                 }
 362 #endif
 363                 if (!strncmp(buf, "vga", 3) &&
 364                     boot_params.screen_info.orig_video_isVGA == 1) {
 365                         max_xpos = boot_params.screen_info.orig_video_cols;
 366                         max_ypos = boot_params.screen_info.orig_video_lines;
 367                         current_ypos = boot_params.screen_info.orig_y;
 368                         early_console_register(&early_vga_console, keep);
 369                 }
 370 #ifdef CONFIG_EARLY_PRINTK_DBGP
 371                 if (!strncmp(buf, "dbgp", 4) && !early_dbgp_init(buf + 4))
 372                         early_console_register(&early_dbgp_console, keep);
 373 #endif
 374 #ifdef CONFIG_HVC_XEN
 375                 if (!strncmp(buf, "xen", 3))
 376                         early_console_register(&xenboot_console, keep);
 377 #endif
 378 #ifdef CONFIG_EARLY_PRINTK_EFI
 379                 if (!strncmp(buf, "efi", 3))
 380                         early_console_register(&early_efi_console, keep);
 381 #endif
 382
 383                 buf++;
 384         }
 385         return 0;
 386 }
 387
 388 early_param("earlyprintk", setup_early_printk);