[mirror_ubuntu-bionic-kernel.git] / arch / blackfin / kernel / early_printk.c

/*
 * allow a console to be used for early printk
 * derived from arch/x86/kernel/early_printk.c
 *
 * Copyright 2007-2009 Analog Devices Inc.
 *
 * Licensed under the GPL-2
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/serial_core.h>
#include <linux/console.h>
#include <linux/string.h>
#include <linux/reboot.h>
#include <asm/blackfin.h>
#include <asm/irq_handler.h>
#include <asm/early_printk.h>

#ifdef CONFIG_SERIAL_BFIN
extern struct console *bfin_earlyserial_init(unsigned int port,
						unsigned int cflag);
#endif
#ifdef CONFIG_BFIN_JTAG_COMM
extern struct console *bfin_jc_early_init(void);
#endif

static struct console *early_console;

/* Default console */
#define DEFAULT_PORT 0
#define DEFAULT_CFLAG CS8|B57600

/* Default console for early crashes */
#define DEFAULT_EARLY_PORT "serial,uart0,57600"

#ifdef CONFIG_SERIAL_CORE
/* What should get here is "0,57600" */
static struct console * __init earlyserial_init(char *buf)
{
	int baud, bit;
	char parity;
	unsigned int serial_port = DEFAULT_PORT;
	unsigned int cflag = DEFAULT_CFLAG;

	serial_port = simple_strtoul(buf, &buf, 10);
	buf++;

	cflag = 0;
	baud = simple_strtoul(buf, &buf, 10);
	switch (baud) {
	case 1200:
		cflag |= B1200;
		break;
	case 2400:
		cflag |= B2400;
		break;
	case 4800:
		cflag |= B4800;
		break;
	case 9600:
		cflag |= B9600;
		break;
	case 19200:
		cflag |= B19200;
		break;
	case 38400:
		cflag |= B38400;
		break;
	case 115200:
		cflag |= B115200;
		break;
	default:
		cflag |= B57600;
	}

	parity = buf[0];
	buf++;
	switch (parity) {
	case 'e':
		cflag |= PARENB;
		break;
	case 'o':
		cflag |= PARODD;
		break;
	}

	bit = simple_strtoul(buf, &buf, 10);
	switch (bit) {
	case 5:
		cflag |= CS5;
		break;
	case 6:
		cflag |= CS6;
		break;
	case 7:
		cflag |= CS7;
		break;
	default:
		cflag |= CS8;
	}

#ifdef CONFIG_SERIAL_BFIN
	return bfin_earlyserial_init(serial_port, cflag);
#else
	return NULL;
#endif

}
#endif

int __init setup_early_printk(char *buf)
{

	/* Crashing in here would be really bad, so check both the var
	   and the pointer before we start using it
	 */
	if (!buf)
		return 0;

	if (!*buf)
		return 0;

	if (early_console != NULL)
		return 0;

#ifdef CONFIG_SERIAL_BFIN
	/* Check for Blackfin Serial */
	if (!strncmp(buf, "serial,uart", 11)) {
		buf += 11;
		early_console = earlyserial_init(buf);
	}
#endif

#ifdef CONFIG_BFIN_JTAG_COMM
	/* Check for Blackfin JTAG */
	if (!strncmp(buf, "jtag", 4)) {
		buf += 4;
		early_console = bfin_jc_early_init();
	}
#endif

#ifdef CONFIG_FB
		/* TODO: add framebuffer console support */
#endif

	if (likely(early_console)) {
		early_console->flags |= CON_BOOT;

		register_console(early_console);
		printk(KERN_INFO "early printk enabled on %s%d\n",
			early_console->name,
			early_console->index);
	}

	return 0;
}

/*
 * Set up a temporary Event Vector Table, so if something bad happens before
 * the kernel is fully started, it doesn't vector off into somewhere we don't
 * know
 */

asmlinkage void __init init_early_exception_vectors(void)
{
	u32 evt;
	SSYNC();

	/*
	 * This starts up the shadow buffer, incase anything crashes before
	 * setup arch
	 */
	mark_shadow_error();
	early_shadow_puts(linux_banner);
	early_shadow_stamp();

	if (CPUID != bfin_cpuid()) {
		early_shadow_puts("Running on wrong machine type, expected");
		early_shadow_reg(CPUID, 16);
		early_shadow_puts(", but running on");
		early_shadow_reg(bfin_cpuid(), 16);
		early_shadow_puts("\n");
	}

	/* cannot program in software:
	 * evt0 - emulation (jtag)
	 * evt1 - reset
	 */
	for (evt = EVT2; evt <= EVT15; evt += 4)
		bfin_write32(evt, early_trap);
	CSYNC();

	/* Set all the return from interrupt, exception, NMI to a known place
	 * so if we do a RETI, RETX or RETN by mistake - we go somewhere known
	 * Note - don't change RETS - we are in a subroutine, or
	 * RETE - since it might screw up if emulator is attached
	 */
	asm("\tRETI = %0; RETX = %0; RETN = %0;\n"
		: : "p"(early_trap));

}

__attribute__((__noreturn__))
asmlinkage void __init early_trap_c(struct pt_regs *fp, void *retaddr)
{
	/* This can happen before the uart is initialized, so initialize
	 * the UART now (but only if we are running on the processor we think
	 * we are compiled for - otherwise we write to MMRs that don't exist,
	 * and cause other problems. Nothing comes out the UART, but it does
	 * end up in the __buf_log.
	 */
	if (likely(early_console == NULL) && CPUID == bfin_cpuid())
		setup_early_printk(DEFAULT_EARLY_PORT);

	if (!shadow_console_enabled()) {
		/* crap - we crashed before setup_arch() */
		early_shadow_puts("panic before setup_arch\n");
		early_shadow_puts("IPEND:");
		early_shadow_reg(fp->ipend, 16);
		if (fp->seqstat & SEQSTAT_EXCAUSE) {
			early_shadow_puts("\nEXCAUSE:");
			early_shadow_reg(fp->seqstat & SEQSTAT_EXCAUSE, 8);
		}
		if (fp->seqstat & SEQSTAT_HWERRCAUSE) {
			early_shadow_puts("\nHWERRCAUSE:");
			early_shadow_reg(
				(fp->seqstat & SEQSTAT_HWERRCAUSE) >> 14, 8);
		}
		early_shadow_puts("\nErr @");
		if (fp->ipend & EVT_EVX)
			early_shadow_reg(fp->retx, 32);
		else
			early_shadow_reg(fp->pc, 32);
#ifdef CONFIG_DEBUG_BFIN_HWTRACE_ON
		early_shadow_puts("\nTrace:");
		if (likely(bfin_read_TBUFSTAT() & TBUFCNT)) {
			while (bfin_read_TBUFSTAT() & TBUFCNT) {
				early_shadow_puts("\nT  :");
				early_shadow_reg(bfin_read_TBUF(), 32);
				early_shadow_puts("\n S :");
				early_shadow_reg(bfin_read_TBUF(), 32);
			}
		}
#endif
		early_shadow_puts("\nUse bfin-elf-addr2line to determine "
			"function names\n");
		/*
		 * We should panic(), but we can't - since panic calls printk,
		 * and printk uses memcpy.
		 * we want to reboot, but if the machine type is different,
		 * can't due to machine specific reboot sequences
		 */
		if (CPUID == bfin_cpuid()) {
			early_shadow_puts("Trying to restart\n");
			machine_restart("");
		}

		early_shadow_puts("Halting, since it is not safe to restart\n");
		while (1)
			asm volatile ("EMUEXCPT; IDLE;\n");

	} else {
		printk(KERN_EMERG "Early panic\n");
		show_regs(fp);
		dump_bfin_trace_buffer();
	}

	panic("Died early");
}

early_param("earlyprintk", setup_early_printk);
Commit	Line	Data
0ae53640	1	/*
96f1050d RG	2	* allow a console to be used for early printk
96f1050d RG	3	* derived from arch/x86/kernel/early_printk.c
0ae53640	4	*
96f1050d	5	* Copyright 2007-2009 Analog Devices Inc.
0ae53640	6	*
96f1050d	7	* Licensed under the GPL-2
0ae53640 RG	8	*/
	9
	10	#include <linux/kernel.h>
	11	#include <linux/init.h>
	12	#include <linux/serial_core.h>
	13	#include <linux/console.h>
	14	#include <linux/string.h>
837ec2d5	15	#include <linux/reboot.h>
0ae53640 RG	16	#include <asm/blackfin.h>
	17	#include <asm/irq_handler.h>
	18	#include <asm/early_printk.h>
	19
	20	#ifdef CONFIG_SERIAL_BFIN
	21	extern struct console *bfin_earlyserial_init(unsigned int port,
	22	unsigned int cflag);
	23	#endif
a88c71e4 MF	24	#ifdef CONFIG_BFIN_JTAG_COMM
	25	extern struct console *bfin_jc_early_init(void);
	26	#endif
0ae53640 RG	27
	28	static struct console *early_console;
	29
337d390b	30	/* Default console */
0ae53640 RG	31	#define DEFAULT_PORT 0
	32	#define DEFAULT_CFLAG CS8\|B57600
	33
337d390b RG	34	/* Default console for early crashes */
	35	#define DEFAULT_EARLY_PORT "serial,uart0,57600"
	36
0ae53640 RG	37	#ifdef CONFIG_SERIAL_CORE
	38	/* What should get here is "0,57600" */
	39	static struct console * __init earlyserial_init(char *buf)
	40	{
	41	int baud, bit;
	42	char parity;
	43	unsigned int serial_port = DEFAULT_PORT;
	44	unsigned int cflag = DEFAULT_CFLAG;
	45
	46	serial_port = simple_strtoul(buf, &buf, 10);
	47	buf++;
	48
	49	cflag = 0;
	50	baud = simple_strtoul(buf, &buf, 10);
	51	switch (baud) {
	52	case 1200:
	53	cflag \|= B1200;
	54	break;
	55	case 2400:
	56	cflag \|= B2400;
	57	break;
	58	case 4800:
	59	cflag \|= B4800;
	60	break;
	61	case 9600:
	62	cflag \|= B9600;
	63	break;
	64	case 19200:
	65	cflag \|= B19200;
	66	break;
	67	case 38400:
	68	cflag \|= B38400;
	69	break;
	70	case 115200:
	71	cflag \|= B115200;
	72	break;
	73	default:
	74	cflag \|= B57600;
	75	}
	76
	77	parity = buf[0];
	78	buf++;
	79	switch (parity) {
	80	case 'e':
	81	cflag \|= PARENB;
	82	break;
	83	case 'o':
	84	cflag \|= PARODD;
	85	break;
	86	}
	87
	88	bit = simple_strtoul(buf, &buf, 10);
	89	switch (bit) {
	90	case 5:
	91	cflag \|= CS5;
	92	break;
	93	case 6:
09b7f4ad	94	cflag \|= CS6;
0ae53640 RG	95	break;
0ae53640 RG	96	case 7:
09b7f4ad	97	cflag \|= CS7;
0ae53640 RG	98	break;
	99	default:
	100	cflag \|= CS8;
	101	}
	102
	103	#ifdef CONFIG_SERIAL_BFIN
	104	return bfin_earlyserial_init(serial_port, cflag);
	105	#else
	106	return NULL;
	107	#endif
	108
	109	}
	110	#endif
	111
	112	int __init setup_early_printk(char *buf)
	113	{
	114
	115	/* Crashing in here would be really bad, so check both the var
	116	and the pointer before we start using it
	117	*/
	118	if (!buf)
	119	return 0;
	120
	121	if (!*buf)
	122	return 0;
	123
	124	if (early_console != NULL)
	125	return 0;
	126
	127	#ifdef CONFIG_SERIAL_BFIN
	128	/* Check for Blackfin Serial */
	129	if (!strncmp(buf, "serial,uart", 11)) {
	130	buf += 11;
	131	early_console = earlyserial_init(buf);
	132	}
	133	#endif
a88c71e4 MF	134
	135	#ifdef CONFIG_BFIN_JTAG_COMM
	136	/* Check for Blackfin JTAG */
	137	if (!strncmp(buf, "jtag", 4)) {
	138	buf += 4;
	139	early_console = bfin_jc_early_init();
	140	}
	141	#endif
	142
0ae53640 RG	143	#ifdef CONFIG_FB
	144	/* TODO: add framebuffer console support */
	145	#endif
	146
	147	if (likely(early_console)) {
	148	early_console->flags \|= CON_BOOT;
	149
	150	register_console(early_console);
	151	printk(KERN_INFO "early printk enabled on %s%d\n",
	152	early_console->name,
	153	early_console->index);
	154	}
	155
	156	return 0;
	157	}
	158
337d390b RG	159	/*
	160	* Set up a temporary Event Vector Table, so if something bad happens before
	161	* the kernel is fully started, it doesn't vector off into somewhere we don't
	162	* know
	163	*/
	164
	165	asmlinkage void __init init_early_exception_vectors(void)
	166	{
685a694f	167	u32 evt;
337d390b RG	168	SSYNC();
337d390b RG	169
837ec2d5 RG	170	/*
	171	* This starts up the shadow buffer, incase anything crashes before
	172	* setup arch
	173	*/
	174	mark_shadow_error();
	175	early_shadow_puts(linux_banner);
	176	early_shadow_stamp();
	177
	178	if (CPUID != bfin_cpuid()) {
	179	early_shadow_puts("Running on wrong machine type, expected");
	180	early_shadow_reg(CPUID, 16);
	181	early_shadow_puts(", but running on");
	182	early_shadow_reg(bfin_cpuid(), 16);
	183	early_shadow_puts("\n");
	184	}
	185
337d390b RG	186	/* cannot program in software:
	187	* evt0 - emulation (jtag)
	188	* evt1 - reset
	189	*/
685a694f MF	190	for (evt = EVT2; evt <= EVT15; evt += 4)
685a694f MF	191	bfin_write32(evt, early_trap);
337d390b RG	192	CSYNC();
337d390b RG	193
79f1ec86	194	/* Set all the return from interrupt, exception, NMI to a known place
337d390b RG	195	* so if we do a RETI, RETX or RETN by mistake - we go somewhere known
	196	* Note - don't change RETS - we are in a subroutine, or
	197	* RETE - since it might screw up if emulator is attached
	198	*/
	199	asm("\tRETI = %0; RETX = %0; RETN = %0;\n"
	200	: : "p"(early_trap));
	201
	202	}
	203
837ec2d5	204	__attribute__((__noreturn__))
337d390b RG	205	asmlinkage void __init early_trap_c(struct pt_regs fp, void retaddr)
	206	{
	207	/* This can happen before the uart is initialized, so initialize
54ebae71 RG	208	* the UART now (but only if we are running on the processor we think
	209	* we are compiled for - otherwise we write to MMRs that don't exist,
	210	* and cause other problems. Nothing comes out the UART, but it does
	211	* end up in the __buf_log.
337d390b	212	*/
54ebae71	213	if (likely(early_console == NULL) && CPUID == bfin_cpuid())
337d390b RG	214	setup_early_printk(DEFAULT_EARLY_PORT);
337d390b RG	215
837ec2d5 RG	216	if (!shadow_console_enabled()) {
	217	/* crap - we crashed before setup_arch() */
	218	early_shadow_puts("panic before setup_arch\n");
	219	early_shadow_puts("IPEND:");
	220	early_shadow_reg(fp->ipend, 16);
	221	if (fp->seqstat & SEQSTAT_EXCAUSE) {
	222	early_shadow_puts("\nEXCAUSE:");
	223	early_shadow_reg(fp->seqstat & SEQSTAT_EXCAUSE, 8);
	224	}
	225	if (fp->seqstat & SEQSTAT_HWERRCAUSE) {
	226	early_shadow_puts("\nHWERRCAUSE:");
	227	early_shadow_reg(
	228	(fp->seqstat & SEQSTAT_HWERRCAUSE) >> 14, 8);
	229	}
	230	early_shadow_puts("\nErr @");
	231	if (fp->ipend & EVT_EVX)
	232	early_shadow_reg(fp->retx, 32);
	233	else
	234	early_shadow_reg(fp->pc, 32);
	235	#ifdef CONFIG_DEBUG_BFIN_HWTRACE_ON
	236	early_shadow_puts("\nTrace:");
	237	if (likely(bfin_read_TBUFSTAT() & TBUFCNT)) {
	238	while (bfin_read_TBUFSTAT() & TBUFCNT) {
	239	early_shadow_puts("\nT :");
	240	early_shadow_reg(bfin_read_TBUF(), 32);
	241	early_shadow_puts("\n S :");
	242	early_shadow_reg(bfin_read_TBUF(), 32);
	243	}
	244	}
	245	#endif
	246	early_shadow_puts("\nUse bfin-elf-addr2line to determine "
	247	"function names\n");
	248	/*
	249	* We should panic(), but we can't - since panic calls printk,
	250	* and printk uses memcpy.
	251	* we want to reboot, but if the machine type is different,
	252	* can't due to machine specific reboot sequences
	253	*/
	254	if (CPUID == bfin_cpuid()) {
	255	early_shadow_puts("Trying to restart\n");
	256	machine_restart("");
	257	}
	258
	259	early_shadow_puts("Halting, since it is not safe to restart\n");
	260	while (1)
	261	asm volatile ("EMUEXCPT; IDLE;\n");
	262
	263	} else {
	264	printk(KERN_EMERG "Early panic\n");
	265	show_regs(fp);
	266	dump_bfin_trace_buffer();
	267	}
337d390b RG	268
	269	panic("Died early");
	270	}
	271
0ae53640	272	early_param("earlyprintk", setup_early_printk);