Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6
[linux-2.6.git] / 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/pgtable.h>
18 #include <linux/usb/ehci_def.h>
19
20 /* Simple VGA output */
21 #define VGABASE         (__ISA_IO_base + 0xb8000)
22
23 static int max_ypos = 25, max_xpos = 80;
24 static int current_ypos = 25, current_xpos;
25
26 static void early_vga_write(struct console *con, const char *str, unsigned n)
27 {
28         char c;
29         int  i, k, j;
30
31         while ((c = *str++) != '\0' && n-- > 0) {
32                 if (current_ypos >= max_ypos) {
33                         /* scroll 1 line up */
34                         for (k = 1, j = 0; k < max_ypos; k++, j++) {
35                                 for (i = 0; i < max_xpos; i++) {
36                                         writew(readw(VGABASE+2*(max_xpos*k+i)),
37                                                VGABASE + 2*(max_xpos*j + i));
38                                 }
39                         }
40                         for (i = 0; i < max_xpos; i++)
41                                 writew(0x720, VGABASE + 2*(max_xpos*j + i));
42                         current_ypos = max_ypos-1;
43                 }
44                 if (c == '\n') {
45                         current_xpos = 0;
46                         current_ypos++;
47                 } else if (c != '\r')  {
48                         writew(((0x7 << 8) | (unsigned short) c),
49                                VGABASE + 2*(max_xpos*current_ypos +
50                                                 current_xpos++));
51                         if (current_xpos >= max_xpos) {
52                                 current_xpos = 0;
53                                 current_ypos++;
54                         }
55                 }
56         }
57 }
58
59 static struct console early_vga_console = {
60         .name =         "earlyvga",
61         .write =        early_vga_write,
62         .flags =        CON_PRINTBUFFER,
63         .index =        -1,
64 };
65
66 /* Serial functions loosely based on a similar package from Klaus P. Gerlicher */
67
68 static int early_serial_base = 0x3f8;  /* ttyS0 */
69
70 #define XMTRDY          0x20
71
72 #define DLAB            0x80
73
74 #define TXR             0       /*  Transmit register (WRITE) */
75 #define RXR             0       /*  Receive register  (READ)  */
76 #define IER             1       /*  Interrupt Enable          */
77 #define IIR             2       /*  Interrupt ID              */
78 #define FCR             2       /*  FIFO control              */
79 #define LCR             3       /*  Line control              */
80 #define MCR             4       /*  Modem control             */
81 #define LSR             5       /*  Line Status               */
82 #define MSR             6       /*  Modem Status              */
83 #define DLL             0       /*  Divisor Latch Low         */
84 #define DLH             1       /*  Divisor latch High        */
85
86 static int early_serial_putc(unsigned char ch)
87 {
88         unsigned timeout = 0xffff;
89
90         while ((inb(early_serial_base + LSR) & XMTRDY) == 0 && --timeout)
91                 cpu_relax();
92         outb(ch, early_serial_base + TXR);
93         return timeout ? 0 : -1;
94 }
95
96 static void early_serial_write(struct console *con, const char *s, unsigned n)
97 {
98         while (*s && n-- > 0) {
99                 if (*s == '\n')
100                         early_serial_putc('\r');
101                 early_serial_putc(*s);
102                 s++;
103         }
104 }
105
106 #define DEFAULT_BAUD 9600
107
108 static __init void early_serial_init(char *s)
109 {
110         unsigned char c;
111         unsigned divisor;
112         unsigned baud = DEFAULT_BAUD;
113         char *e;
114
115         if (*s == ',')
116                 ++s;
117
118         if (*s) {
119                 unsigned port;
120                 if (!strncmp(s, "0x", 2)) {
121                         early_serial_base = simple_strtoul(s, &e, 16);
122                 } else {
123                         static const int __initconst bases[] = { 0x3f8, 0x2f8 };
124
125                         if (!strncmp(s, "ttyS", 4))
126                                 s += 4;
127                         port = simple_strtoul(s, &e, 10);
128                         if (port > 1 || s == e)
129                                 port = 0;
130                         early_serial_base = bases[port];
131                 }
132                 s += strcspn(s, ",");
133                 if (*s == ',')
134                         s++;
135         }
136
137         outb(0x3, early_serial_base + LCR);     /* 8n1 */
138         outb(0, early_serial_base + IER);       /* no interrupt */
139         outb(0, early_serial_base + FCR);       /* no fifo */
140         outb(0x3, early_serial_base + MCR);     /* DTR + RTS */
141
142         if (*s) {
143                 baud = simple_strtoul(s, &e, 0);
144                 if (baud == 0 || s == e)
145                         baud = DEFAULT_BAUD;
146         }
147
148         divisor = 115200 / baud;
149         c = inb(early_serial_base + LCR);
150         outb(c | DLAB, early_serial_base + LCR);
151         outb(divisor & 0xff, early_serial_base + DLL);
152         outb((divisor >> 8) & 0xff, early_serial_base + DLH);
153         outb(c & ~DLAB, early_serial_base + LCR);
154 }
155
156 static struct console early_serial_console = {
157         .name =         "earlyser",
158         .write =        early_serial_write,
159         .flags =        CON_PRINTBUFFER,
160         .index =        -1,
161 };
162
163 /* Direct interface for emergencies */
164 static struct console *early_console = &early_vga_console;
165 static int __initdata early_console_initialized;
166
167 asmlinkage void early_printk(const char *fmt, ...)
168 {
169         char buf[512];
170         int n;
171         va_list ap;
172
173         va_start(ap, fmt);
174         n = vscnprintf(buf, sizeof(buf), fmt, ap);
175         early_console->write(early_console, buf, n);
176         va_end(ap);
177 }
178
179 static inline void early_console_register(struct console *con, int keep_early)
180 {
181         if (early_console->index != -1) {
182                 printk(KERN_CRIT "ERROR: earlyprintk= %s already used\n",
183                        con->name);
184                 return;
185         }
186         early_console = con;
187         if (keep_early)
188                 early_console->flags &= ~CON_BOOT;
189         else
190                 early_console->flags |= CON_BOOT;
191         register_console(early_console);
192 }
193
194 static int __init setup_early_printk(char *buf)
195 {
196         int keep;
197
198         if (!buf)
199                 return 0;
200
201         if (early_console_initialized)
202                 return 0;
203         early_console_initialized = 1;
204
205         keep = (strstr(buf, "keep") != NULL);
206
207         while (*buf != '\0') {
208                 if (!strncmp(buf, "serial", 6)) {
209                         buf += 6;
210                         early_serial_init(buf);
211                         early_console_register(&early_serial_console, keep);
212                         if (!strncmp(buf, ",ttyS", 5))
213                                 buf += 5;
214                 }
215                 if (!strncmp(buf, "ttyS", 4)) {
216                         early_serial_init(buf + 4);
217                         early_console_register(&early_serial_console, keep);
218                 }
219                 if (!strncmp(buf, "vga", 3) &&
220                     boot_params.screen_info.orig_video_isVGA == 1) {
221                         max_xpos = boot_params.screen_info.orig_video_cols;
222                         max_ypos = boot_params.screen_info.orig_video_lines;
223                         current_ypos = boot_params.screen_info.orig_y;
224                         early_console_register(&early_vga_console, keep);
225                 }
226 #ifdef CONFIG_EARLY_PRINTK_DBGP
227                 if (!strncmp(buf, "dbgp", 4) && !early_dbgp_init(buf + 4))
228                         early_console_register(&early_dbgp_console, keep);
229 #endif
230 #ifdef CONFIG_HVC_XEN
231                 if (!strncmp(buf, "xen", 3))
232                         early_console_register(&xenboot_console, keep);
233 #endif
234                 buf++;
235         }
236         return 0;
237 }
238
239 early_param("earlyprintk", setup_early_printk);