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/usb/xhci-dbgp.h>
  21 #include <linux/efi.h>
  22 #include <asm/efi.h>
  23 #include <asm/pci_x86.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
  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
  99 static unsigned int io_serial_in(unsigned long addr, int offset)
 100 {
 101         return inb(addr + offset);
 102 }
 103
 104 static void io_serial_out(unsigned long addr, int offset, int value)
 105 {
 106         outb(value, addr + offset);
 107 }
 108
 109 static unsigned int (*serial_in)(unsigned long addr, int offset) = io_serial_in;
 110 static void (*serial_out)(unsigned long addr, int offset, int value) = io_serial_out;
 111
 112 static int early_serial_putc(unsigned char ch)
 113 {
 114         unsigned timeout = 0xffff;
 115
 116         while ((serial_in(early_serial_base, LSR) & XMTRDY) == 0 && --timeout)
 117                 cpu_relax();
 118         serial_out(early_serial_base, TXR, ch);
 119         return timeout ? 0 : -1;
 120 }
 121
 122 static void early_serial_write(struct console *con, const char *s, unsigned n)
 123 {
 124         while (*s && n-- > 0) {
 125                 if (*s == '\n')
 126                         early_serial_putc('\r');
 127                 early_serial_putc(*s);
 128                 s++;
 129         }
 130 }
 131
 132 static __init void early_serial_hw_init(unsigned divisor)
 133 {
 134         unsigned char c;
 135
 136         serial_out(early_serial_base, LCR, 0x3);        /* 8n1 */
 137         serial_out(early_serial_base, IER, 0);  /* no interrupt */
 138         serial_out(early_serial_base, FCR, 0);  /* no fifo */
 139         serial_out(early_serial_base, MCR, 0x3);        /* DTR + RTS */
 140
 141         c = serial_in(early_serial_base, LCR);
 142         serial_out(early_serial_base, LCR, c | DLAB);
 143         serial_out(early_serial_base, DLL, divisor & 0xff);
 144         serial_out(early_serial_base, DLH, (divisor >> 8) & 0xff);
 145         serial_out(early_serial_base, LCR, c & ~DLAB);
 146 }
 147
 148 #define DEFAULT_BAUD 9600
 149
 150 static __init void early_serial_init(char *s)
 151 {
 152         unsigned divisor;
 153         unsigned long baud = DEFAULT_BAUD;
 154         char *e;
 155
 156         if (*s == ',')
 157                 ++s;
 158
 159         if (*s) {
 160                 unsigned port;
 161                 if (!strncmp(s, "0x", 2)) {
 162                         early_serial_base = simple_strtoul(s, &e, 16);
 163                 } else {
 164                         static const int __initconst bases[] = { 0x3f8, 0x2f8 };
 165
 166                         if (!strncmp(s, "ttyS", 4))
 167                                 s += 4;
 168                         port = simple_strtoul(s, &e, 10);
 169                         if (port > 1 || s == e)
 170                                 port = 0;
 171                         early_serial_base = bases[port];
 172                 }
 173                 s += strcspn(s, ",");
 174                 if (*s == ',')
 175                         s++;
 176         }
 177
 178         if (*s) {
 179                 baud = simple_strtoull(s, &e, 0);
 180
 181                 if (baud == 0 || s == e)
 182                         baud = DEFAULT_BAUD;
 183         }
 184
 185         /* Convert from baud to divisor value */
 186         divisor = 115200 / baud;
 187
 188         /* These will always be IO based ports */
 189         serial_in = io_serial_in;
 190         serial_out = io_serial_out;
 191
 192         /* Set up the HW */
 193         early_serial_hw_init(divisor);
 194 }
 195
 196 #ifdef CONFIG_PCI
 197 static void mem32_serial_out(unsigned long addr, int offset, int value)
 198 {
 199         u32 __iomem *vaddr = (u32 __iomem *)addr;
 200         /* shift implied by pointer type */
 201         writel(value, vaddr + offset);
 202 }
 203
 204 static unsigned int mem32_serial_in(unsigned long addr, int offset)
 205 {
 206         u32 __iomem *vaddr = (u32 __iomem *)addr;
 207         /* shift implied by pointer type */
 208         return readl(vaddr + offset);
 209 }
 210
 211 /*
 212  * early_pci_serial_init()
 213  *
 214  * This function is invoked when the early_printk param starts with "pciserial"
 215  * The rest of the param should be ",B:D.F,baud" where B, D & F describe the
 216  * location of a PCI device that must be a UART device.
 217  */
 218 static __init void early_pci_serial_init(char *s)
 219 {
 220         unsigned divisor;
 221         unsigned long baud = DEFAULT_BAUD;
 222         u8 bus, slot, func;
 223         u32 classcode, bar0;
 224         u16 cmdreg;
 225         char *e;
 226
 227
 228         /*
 229          * First, part the param to get the BDF values
 230          */
 231         if (*s == ',')
 232                 ++s;
 233
 234         if (*s == 0)
 235                 return;
 236
 237         bus = (u8)simple_strtoul(s, &e, 16);
 238         s = e;
 239         if (*s != ':')
 240                 return;
 241         ++s;
 242         slot = (u8)simple_strtoul(s, &e, 16);
 243         s = e;
 244         if (*s != '.')
 245                 return;
 246         ++s;
 247         func = (u8)simple_strtoul(s, &e, 16);
 248         s = e;
 249
 250         /* A baud might be following */
 251         if (*s == ',')
 252                 s++;
 253
 254         /*
 255          * Second, find the device from the BDF
 256          */
 257         cmdreg = read_pci_config(bus, slot, func, PCI_COMMAND);
 258         classcode = read_pci_config(bus, slot, func, PCI_CLASS_REVISION);
 259         bar0 = read_pci_config(bus, slot, func, PCI_BASE_ADDRESS_0);
 260
 261         /*
 262          * Verify it is a UART type device
 263          */
 264         if (((classcode >> 16 != PCI_CLASS_COMMUNICATION_MODEM) &&
 265              (classcode >> 16 != PCI_CLASS_COMMUNICATION_SERIAL)) ||
 266            (((classcode >> 8) & 0xff) != 0x02)) /* 16550 I/F at BAR0 */
 267                 return;
 268
 269         /*
 270          * Determine if it is IO or memory mapped
 271          */
 272         if (bar0 & 0x01) {
 273                 /* it is IO mapped */
 274                 serial_in = io_serial_in;
 275                 serial_out = io_serial_out;
 276                 early_serial_base = bar0&0xfffffffc;
 277                 write_pci_config(bus, slot, func, PCI_COMMAND,
 278                                                 cmdreg|PCI_COMMAND_IO);
 279         } else {
 280                 /* It is memory mapped - assume 32-bit alignment */
 281                 serial_in = mem32_serial_in;
 282                 serial_out = mem32_serial_out;
 283                 /* WARNING! assuming the address is always in the first 4G */
 284                 early_serial_base =
 285                         (unsigned long)early_ioremap(bar0 & 0xfffffff0, 0x10);
 286                 write_pci_config(bus, slot, func, PCI_COMMAND,
 287                                                 cmdreg|PCI_COMMAND_MEMORY);
 288         }
 289
 290         /*
 291          * Lastly, initialize the hardware
 292          */
 293         if (*s) {
 294                 if (strcmp(s, "nocfg") == 0)
 295                         /* Sometimes, we want to leave the UART alone
 296                          * and assume the BIOS has set it up correctly.
 297                          * "nocfg" tells us this is the case, and we
 298                          * should do no more setup.
 299                          */
 300                         return;
 301                 if (kstrtoul(s, 0, &baud) < 0 || baud == 0)
 302                         baud = DEFAULT_BAUD;
 303         }
 304
 305         /* Convert from baud to divisor value */
 306         divisor = 115200 / baud;
 307
 308         /* Set up the HW */
 309         early_serial_hw_init(divisor);
 310 }
 311 #endif
 312
 313 static struct console early_serial_console = {
 314         .name =         "earlyser",
 315         .write =        early_serial_write,
 316         .flags =        CON_PRINTBUFFER,
 317         .index =        -1,
 318 };
 319
 320 static void early_console_register(struct console *con, int keep_early)
 321 {
 322         if (con->index != -1) {
 323                 printk(KERN_CRIT "ERROR: earlyprintk= %s already used\n",
 324                        con->name);
 325                 return;
 326         }
 327         early_console = con;
 328         if (keep_early)
 329                 early_console->flags &= ~CON_BOOT;
 330         else
 331                 early_console->flags |= CON_BOOT;
 332         register_console(early_console);
 333 }
 334
 335 static int __init setup_early_printk(char *buf)
 336 {
 337         int keep;
 338
 339         if (!buf)
 340                 return 0;
 341
 342         if (early_console)
 343                 return 0;
 344
 345         keep = (strstr(buf, "keep") != NULL);
 346
 347         while (*buf != '\0') {
 348                 if (!strncmp(buf, "serial", 6)) {
 349                         buf += 6;
 350                         early_serial_init(buf);
 351                         early_console_register(&early_serial_console, keep);
 352                         if (!strncmp(buf, ",ttyS", 5))
 353                                 buf += 5;
 354                 }
 355                 if (!strncmp(buf, "ttyS", 4)) {
 356                         early_serial_init(buf + 4);
 357                         early_console_register(&early_serial_console, keep);
 358                 }
 359 #ifdef CONFIG_PCI
 360                 if (!strncmp(buf, "pciserial", 9)) {
 361                         early_pci_serial_init(buf + 9);
 362                         early_console_register(&early_serial_console, keep);
 363                         buf += 9; /* Keep from match the above "serial" */
 364                 }
 365 #endif
 366                 if (!strncmp(buf, "vga", 3) &&
 367                     boot_params.screen_info.orig_video_isVGA == 1) {
 368                         max_xpos = boot_params.screen_info.orig_video_cols;
 369                         max_ypos = boot_params.screen_info.orig_video_lines;
 370                         current_ypos = boot_params.screen_info.orig_y;
 371                         early_console_register(&early_vga_console, keep);
 372                 }
 373 #ifdef CONFIG_EARLY_PRINTK_DBGP
 374                 if (!strncmp(buf, "dbgp", 4) && !early_dbgp_init(buf + 4))
 375                         early_console_register(&early_dbgp_console, keep);
 376 #endif
 377 #ifdef CONFIG_HVC_XEN
 378                 if (!strncmp(buf, "xen", 3))
 379                         early_console_register(&xenboot_console, keep);
 380 #endif
 381 #ifdef CONFIG_EARLY_PRINTK_EFI
 382                 if (!strncmp(buf, "efi", 3))
 383                         early_console_register(&early_efi_console, keep);
 384 #endif
 385 #ifdef CONFIG_EARLY_PRINTK_USB_XDBC
 386                 if (!strncmp(buf, "xdbc", 4))
 387                         early_xdbc_parse_parameter(buf + 4);
 388 #endif
 389
 390                 buf++;
 391         }
 392         return 0;
 393 }
 394
 395 early_param("earlyprintk", setup_early_printk);