x86, setup: reorganize the early console setup

Separate early_serial_console from tty.c

This allows for reuse of
early_serial_console.c/string.c/printf.c/cmdline.c in boot/compressed/.

-v2: according to hpa, don't include string.c etc
-v3: compressed/misc.c must have early_serial_base as static, so move it back to tty.c
     for setup code

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <4C568D2B.205@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

arch/x86/boot/Makefile

@@ -26,10 +26,10 @@ targets		:= vmlinux.bin setup.bin setup.elf bzImage
 targets		+= fdimage fdimage144 fdimage288 image.iso mtools.conf
 subdir-		:= compressed
 
-setup-y		+= a20.o bioscall.o cmdline.o copy.o cpu.o cpucheck.o edd.o
-setup-y		+= header.o main.o mca.o memory.o pm.o pmjump.o
-setup-y		+= printf.o regs.o string.o tty.o video.o video-mode.o
-setup-y		+= version.o
+setup-y		+= a20.o bioscall.o cmdline.o copy.o cpu.o cpucheck.o
+setup-y		+= early_serial_console.o edd.o header.o main.o mca.o memory.o
+setup-y		+= pm.o pmjump.o printf.o regs.o string.o tty.o video.o
+setup-y		+= video-mode.o version.o
 setup-$(CONFIG_X86_APM_BOOT) += apm.o
 
 # The link order of the video-*.o modules can matter.  In particular,

arch/x86/boot/boot.h

@@ -200,21 +200,7 @@ static inline int memcmp_gs(const void *s1, addr_t s2, size_t len)
 	return diff;
 }
 
-static inline int isdigit(int ch)
-{
-	return (ch >= '0') && (ch <= '9');
-}
-
-static inline int isxdigit(int ch)
-{
-	if (isdigit(ch))
-		return true;
-
-	if ((ch >= 'a') && (ch <= 'f'))
-		return true;
-
-	return (ch >= 'A') && (ch <= 'F');
-}
+#include "isdigit.h"
 
 /* Heap -- available for dynamic lists. */
 extern char _end[];
@@ -300,8 +286,18 @@ struct biosregs {
 void intcall(u8 int_no, const struct biosregs *ireg, struct biosregs *oreg);
 
 /* cmdline.c */
-int cmdline_find_option(const char *option, char *buffer, int bufsize);
-int cmdline_find_option_bool(const char *option);
+int __cmdline_find_option(u32 cmdline_ptr, const char *option, char *buffer, int bufsize);
+int __cmdline_find_option_bool(u32 cmdline_ptr, const char *option);
+static inline int cmdline_find_option(const char *option, char *buffer, int bufsize)
+{
+	return __cmdline_find_option(boot_params.hdr.cmd_line_ptr, option, buffer, bufsize);
+}
+
+static inline int cmdline_find_option_bool(const char *option)
+{
+	return __cmdline_find_option_bool(boot_params.hdr.cmd_line_ptr, option);
+}
+
 
 /* cpu.c, cpucheck.c */
 struct cpu_features {
@@ -313,6 +309,10 @@ extern struct cpu_features cpu;
 int check_cpu(int *cpu_level_ptr, int *req_level_ptr, u32 **err_flags_ptr);
 int validate_cpu(void);
 
+/* early_serial_console.c */
+extern int early_serial_base;
+void console_init(void);
+
 /* edd.c */
 void query_edd(void);
 
@@ -348,7 +348,6 @@ unsigned int atou(const char *s);
 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base);
 
 /* tty.c */
-void console_init(void);
 void puts(const char *);
 void putchar(int);
 int getchar(void);

arch/x86/boot/cmdline.c

@@ -27,9 +27,8 @@ static inline int myisspace(u8 c)
  * Returns the length of the argument (regardless of if it was
  * truncated to fit in the buffer), or -1 on not found.
  */
-int cmdline_find_option(const char *option, char *buffer, int bufsize)
+int __cmdline_find_option(u32 cmdline_ptr, const char *option, char *buffer, int bufsize)
 {
-	u32 cmdline_ptr = boot_params.hdr.cmd_line_ptr;
 	addr_t cptr;
 	char c;
 	int len = -1;
@@ -100,9 +99,8 @@ int cmdline_find_option(const char *option, char *buffer, int bufsize)
  * Returns the position of that option (starts counting with 1)
  * or 0 on not found
  */
-int cmdline_find_option_bool(const char *option)
+int __cmdline_find_option_bool(u32 cmdline_ptr, const char *option)
 {
-	u32 cmdline_ptr = boot_params.hdr.cmd_line_ptr;
 	addr_t cptr;
 	char c;
 	int pos = 0, wstart = 0;

arch/x86/boot/early_serial_console.c

@@ -0,0 +1,139 @@
+#include "boot.h"
+
+#define DEFAULT_SERIAL_PORT 0x3f8 /* ttyS0 */
+
+#define XMTRDY          0x20
+
+#define DLAB		0x80
+
+#define TXR             0       /*  Transmit register (WRITE) */
+#define RXR             0       /*  Receive register  (READ)  */
+#define IER             1       /*  Interrupt Enable          */
+#define IIR             2       /*  Interrupt ID              */
+#define FCR             2       /*  FIFO control              */
+#define LCR             3       /*  Line control              */
+#define MCR             4       /*  Modem control             */
+#define LSR             5       /*  Line Status               */
+#define MSR             6       /*  Modem Status              */
+#define DLL             0       /*  Divisor Latch Low         */
+#define DLH             1       /*  Divisor latch High        */
+
+#define DEFAULT_BAUD 9600
+
+static void early_serial_init(int port, int baud)
+{
+	unsigned char c;
+	unsigned divisor;
+
+	outb(0x3, port + LCR);	/* 8n1 */
+	outb(0, port + IER);	/* no interrupt */
+	outb(0, port + FCR);	/* no fifo */
+	outb(0x3, port + MCR);	/* DTR + RTS */
+
+	divisor	= 115200 / baud;
+	c = inb(port + LCR);
+	outb(c | DLAB, port + LCR);
+	outb(divisor & 0xff, port + DLL);
+	outb((divisor >> 8) & 0xff, port + DLH);
+	outb(c & ~DLAB, port + LCR);
+
+	early_serial_base = port;
+}
+
+static void parse_earlyprintk(void)
+{
+	int baud = DEFAULT_BAUD;
+	char arg[32];
+	int pos = 0;
+	int port = 0;
+
+	if (cmdline_find_option("earlyprintk", arg, sizeof arg) > 0) {
+		char *e;
+
+		if (!strncmp(arg, "serial", 6)) {
+			port = DEFAULT_SERIAL_PORT;
+			pos += 6;
+		}
+
+		if (arg[pos] == ',')
+			pos++;
+
+		if (!strncmp(arg, "ttyS", 4)) {
+			static const int bases[] = { 0x3f8, 0x2f8 };
+			int idx = 0;
+
+			if (!strncmp(arg + pos, "ttyS", 4))
+				pos += 4;
+
+			if (arg[pos++] == '1')
+				idx = 1;
+
+			port = bases[idx];
+		}
+
+		if (arg[pos] == ',')
+			pos++;
+
+		baud = simple_strtoull(arg + pos, &e, 0);
+		if (baud == 0 || arg + pos == e)
+			baud = DEFAULT_BAUD;
+	}
+
+	if (port)
+		early_serial_init(port, baud);
+}
+
+#define BASE_BAUD (1843200/16)
+static unsigned int probe_baud(int port)
+{
+	unsigned char lcr, dll, dlh;
+	unsigned int quot;
+
+	lcr = inb(port + LCR);
+	outb(lcr | DLAB, port + LCR);
+	dll = inb(port + DLL);
+	dlh = inb(port + DLH);
+	outb(lcr, port + LCR);
+	quot = (dlh << 8) | dll;
+
+	return BASE_BAUD / quot;
+}
+
+static void parse_console_uart8250(void)
+{
+	char optstr[64], *options;
+	int baud = DEFAULT_BAUD;
+	int port = 0;
+
+	/*
+	 * console=uart8250,io,0x3f8,115200n8
+	 * need to make sure it is last one console !
+	 */
+	if (cmdline_find_option("console", optstr, sizeof optstr) <= 0)
+		return;
+
+	options = optstr;
+
+	if (!strncmp(options, "uart8250,io,", 12))
+		port = simple_strtoull(options + 12, &options, 0);
+	else if (!strncmp(options, "uart,io,", 8))
+		port = simple_strtoull(options + 8, &options, 0);
+	else
+		return;
+
+	if (options && (options[0] == ','))
+		baud = simple_strtoull(options + 1, &options, 0);
+	else
+		baud = probe_baud(port);
+
+	if (port)
+		early_serial_init(port, baud);
+}
+
+void console_init(void)
+{
+	parse_earlyprintk();
+
+	if (!early_serial_base)
+		parse_console_uart8250();
+}

arch/x86/boot/isdigit.h

@@ -0,0 +1,21 @@
+#ifndef BOOT_ISDIGIT_H
+
+#define BOOT_ISDIGIT_H
+
+static inline int isdigit(int ch)
+{
+	return (ch >= '0') && (ch <= '9');
+}
+
+static inline int isxdigit(int ch)
+{
+	if (isdigit(ch))
+		return true;
+
+	if ((ch >= 'a') && (ch <= 'f'))
+		return true;
+
+	return (ch >= 'A') && (ch <= 'F');
+}
+
+#endif

arch/x86/boot/printf.c

@@ -34,7 +34,7 @@ static int skip_atoi(const char **s)
 #define SMALL	32		/* Must be 32 == 0x20 */
 #define SPECIAL	64		/* 0x */
 
-#define do_div(n,base) ({ \
+#define __do_div(n, base) ({ \
 int __res; \
 __res = ((unsigned long) n) % (unsigned) base; \
 n = ((unsigned long) n) / (unsigned) base; \
@@ -83,7 +83,7 @@ static char *number(char *str, long num, int base, int size, int precision,
 		tmp[i++] = '0';
 	else
 		while (num != 0)
-			tmp[i++] = (digits[do_div(num, base)] | locase);
+			tmp[i++] = (digits[__do_div(num, base)] | locase);
 	if (i > precision)
 		precision = i;
 	size -= precision;