xmon.c

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/*
 * Routines providing a simple monitor for use on the PowerMac.
 *
 * Copyright (C) 1996 Paul Mackerras.
 */
#include <linux/config.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <asm/ptrace.h>
#include <asm/string.h>
#include <asm/prom.h>
#include <asm/bitops.h>
#include "nonstdio.h"
#include "privinst.h"

#define scanhex	xmon_scanhex
#define skipbl	xmon_skipbl

#ifdef CONFIG_SMP
static unsigned long cpus_in_xmon = 0;
static unsigned long got_xmon = 0;
static volatile int take_xmon = -1;
#endif /* CONFIG_SMP */

static unsigned adrs;
static int size = 1;
static unsigned ndump = 64;
static unsigned nidump = 16;
static unsigned ncsum = 4096;
static int termch;

static u_int bus_error_jmp[100];
#define setjmp xmon_setjmp
#define longjmp xmon_longjmp

/* Breakpoint stuff */
struct bpt {
	unsigned address;
	unsigned instr;
	unsigned count;
	unsigned char enabled;
};

#define NBPTS	16
static struct bpt bpts[NBPTS];
static struct bpt dabr;
static struct bpt iabr;
static unsigned bpinstr = 0x7fe00008;	/* trap */

/* Prototypes */
extern void (*debugger_fault_handler)(struct pt_regs *);
static int cmds(struct pt_regs *);
static int mread(unsigned, void *, int);
static int mwrite(unsigned, void *, int);
static void handle_fault(struct pt_regs *);
static void byterev(unsigned char *, int);
static void memex(void);
static int bsesc(void);
static void dump(void);
static void prdump(unsigned, int);
#ifdef __MWERKS__
static void prndump(unsigned, int);
static int nvreadb(unsigned);
#endif
static int ppc_inst_dump(unsigned, int);
void print_address(unsigned);
static int getsp(void);
static void dump_hash_table(void);
static void backtrace(struct pt_regs *);
static void excprint(struct pt_regs *);
static void prregs(struct pt_regs *);
static void memops(int);
static void memlocate(void);
static void memzcan(void);
static void memdiffs(unsigned char *, unsigned char *, unsigned, unsigned);
int skipbl(void);
int scanhex(unsigned *valp);
static void scannl(void);
static int hexdigit(int);
void getstring(char *, int);
static void flush_input(void);
static int inchar(void);
static void take_input(char *);
/* static void openforth(void); */
static unsigned read_spr(int);
static void write_spr(int, unsigned);
static void super_regs(void);
static void print_sysmap(void);
static void remove_bpts(void);
static void insert_bpts(void);
static struct bpt *at_breakpoint(unsigned pc);
static void bpt_cmds(void);
static void cacheflush(void);
#ifdef CONFIG_SMP
static void cpu_cmd(void);
#endif /* CONFIG_SMP */
#if 0 /* Makes compile with -Wall */
static char *pretty_print_addr(unsigned long addr);
static char *lookup_name(unsigned long addr);
#endif
static void csum(void);

extern int print_insn_big_powerpc(FILE *, unsigned long, unsigned);
extern void printf(const char *fmt, ...);
extern int putchar(int ch);
extern int setjmp(u_int *);
extern void longjmp(u_int *, int);

extern void xmon_enter(void);
extern void xmon_leave(void);

#define GETWORD(v)	(((v)[0] << 24) + ((v)[1] << 16) + ((v)[2] << 8) + (v)[3])

#define isxdigit(c)	(('0' <= (c) && (c) <= '9') \
			 || ('a' <= (c) && (c) <= 'f') \
			 || ('A' <= (c) && (c) <= 'F'))
#define isalnum(c)	(('0' <= (c) && (c) <= '9') \
			 || ('a' <= (c) && (c) <= 'z') \
			 || ('A' <= (c) && (c) <= 'Z'))

static char *help_string = "\
Commands:\n\
  d	dump bytes\n\
  di	dump instructions\n\
  df	dump float values\n\
  dd	dump double values\n\
  e	print exception information\n\
  h	dump hash table\n\
  m	examine/change memory\n\
  mm	move a block of memory\n\
  ms	set a block of memory\n\
  md	compare two blocks of memory\n\
  M	print System.map\n\
  r	print registers\n\
  S	print special registers\n\
  t	print backtrace\n\
  x	exit monitor\n\
";

static int xmon_trace[NR_CPUS];
#define SSTEP	1		/* stepping because of 's' command */
#define BRSTEP	2		/* stepping over breakpoint */

static struct pt_regs *xmon_regs[NR_CPUS];

void
xmon(struct pt_regs *excp)
{
	struct pt_regs regs;
	int msr, cmd;

	if (excp == NULL) {
		asm volatile ("stw	0,0(%0)\n\
			lwz	0,0(1)\n\
			stw	0,4(%0)\n\
			stmw	2,8(%0)" : : "b" (&regs));
		regs.nip = regs.link = ((unsigned long *)regs.gpr[1])[1];
		regs.msr = get_msr();
		regs.ctr = get_ctr();
		regs.xer = get_xer();
		regs.ccr = get_cr();
		regs.trap = 0;
		excp = &regs;
	}

	msr = get_msr();
	set_msr(msr & ~0x8000);	/* disable interrupts */
	xmon_regs[smp_processor_id()] = excp;
	xmon_enter();
	excprint(excp);
#ifdef CONFIG_SMP
	if (test_and_set_bit(smp_processor_id(), &cpus_in_xmon))
		for (;;)
			;
	while (test_and_set_bit(0, &got_xmon)) {
		if (take_xmon == smp_processor_id()) {
			take_xmon = -1;
			break;
		}
	}
	/*
	 * XXX: breakpoints are removed while any cpu is in xmon
	 */
#endif /* CONFIG_SMP */
	remove_bpts();
	cmd = cmds(excp);
	if (cmd == 's') {
		xmon_trace[smp_processor_id()] = SSTEP;
		excp->msr |= 0x400;
	} else if (at_breakpoint(excp->nip)) {
		xmon_trace[smp_processor_id()] = BRSTEP;
		excp->msr |= 0x400;
	} else {
		xmon_trace[smp_processor_id()] = 0;
		insert_bpts();
	}
	xmon_leave();
	xmon_regs[smp_processor_id()] = 0;
#ifdef CONFIG_SMP
	clear_bit(0, &got_xmon);
	clear_bit(smp_processor_id(), &cpus_in_xmon);
#endif /* CONFIG_SMP */
	set_msr(msr);		/* restore interrupt enable */
}

void
xmon_irq(int irq, void *d, struct pt_regs *regs)
{
	unsigned long flags;
	save_flags(flags);cli();
	printf("Keyboard interrupt\n");
	xmon(regs);
	restore_flags(flags);
}

int
xmon_bpt(struct pt_regs *regs)
{
	struct bpt *bp;

	bp = at_breakpoint(regs->nip);
	if (!bp)
		return 0;
	if (bp->count) {
		--bp->count;
		remove_bpts();
		excprint(regs);
		xmon_trace[smp_processor_id()] = BRSTEP;
		regs->msr |= 0x400;
	} else {
		xmon(regs);
	}
	return 1;
}

int
xmon_sstep(struct pt_regs *regs)
{
	if (!xmon_trace[smp_processor_id()])
		return 0;
	if (xmon_trace[smp_processor_id()] == BRSTEP) {
		xmon_trace[smp_processor_id()] = 0;
		insert_bpts();
	} else {
		xmon(regs);
	}
	return 1;
}

int
xmon_dabr_match(struct pt_regs *regs)
{
	if (dabr.enabled && dabr.count) {
		--dabr.count;
		remove_bpts();
		excprint(regs);
		xmon_trace[smp_processor_id()] = BRSTEP;
		regs->msr |= 0x400;
	} else {
		dabr.instr = regs->nip;
		xmon(regs);
	}
	return 1;
}

int
xmon_iabr_match(struct pt_regs *regs)
{
	if (iabr.enabled && iabr.count) {
		--iabr.count;
		remove_bpts();
		excprint(regs);
		xmon_trace[smp_processor_id()] = BRSTEP;
		regs->msr |= 0x400;
	} else {
		xmon(regs);
	}
	return 1;
}

static struct bpt *
at_breakpoint(unsigned pc)
{
	int i;
	struct bpt *bp;

	if (dabr.enabled && pc == dabr.instr)
		return &dabr;
	if (iabr.enabled && pc == iabr.address)
		return &iabr;
	bp = bpts;
	for (i = 0; i < NBPTS; ++i, ++bp)
		if (bp->enabled && pc == bp->address)
			return bp;
	return 0;
}

static void
insert_bpts()
{
	int i;
	struct bpt *bp;

	bp = bpts;
	for (i = 0; i < NBPTS; ++i, ++bp) {
		if (!bp->enabled)
			continue;
		if (mread(bp->address, &bp->instr, 4) != 4
		    || mwrite(bp->address, &bpinstr, 4) != 4) {
			printf("Couldn't insert breakpoint at %x, disabling\n",
			       bp->address);
			bp->enabled = 0;
		}
		store_inst((void *) bp->address);
	}
#if !defined(CONFIG_8xx) && !defined(CONFIG_POWER4)
	if (dabr.enabled)
		set_dabr(dabr.address);
	if (iabr.enabled)
		set_iabr(iabr.address);
#endif
}

static void
remove_bpts()
{
	int i;
	struct bpt *bp;
	unsigned instr;

#if !defined(CONFIG_8xx) && !defined(CONFIG_POWER4)
	set_dabr(0);
	set_iabr(0);
#endif
	bp = bpts;
	for (i = 0; i < NBPTS; ++i, ++bp) {
		if (!bp->enabled)
			continue;
		if (mread(bp->address, &instr, 4) == 4
		    && instr == bpinstr
		    && mwrite(bp->address, &bp->instr, 4) != 4)
			printf("Couldn't remove breakpoint at %x\n",
			       bp->address);
		store_inst((void *) bp->address);
	}
}

static char *last_cmd;

/* Command interpreting routine */
static int
cmds(struct pt_regs *excp)
{
	int cmd;

	last_cmd = NULL;
	for(;;) {
#ifdef CONFIG_SMP
		printf("%d:", smp_processor_id());
#endif /* CONFIG_SMP */
		printf("mon> ");
		fflush(stdout);
		flush_input();
		termch = 0;
		cmd = skipbl();
		if( cmd == '\n' ) {
			if (last_cmd == NULL)
				continue;
			take_input(last_cmd);
			last_cmd = NULL;
			cmd = inchar();
		}
		switch (cmd) {
		case 'm':
			cmd = inchar();
			switch (cmd) {
			case 'm':
			case 's':
			case 'd':
				memops(cmd);
				break;
			case 'l':
				memlocate();
				break;
			case 'z':
				memzcan();
				break;
			default:
				termch = cmd;
				memex();
			}
			break;
		case 'd':
			dump();
			break;
		case 'r':
			if (excp != NULL)
				prregs(excp);	/* print regs */
			break;
		case 'e':
			if (excp == NULL)
				printf("No exception information\n");
			else
				excprint(excp);
			break;
		case 'M':
			print_sysmap();
		case 'S':
			super_regs();
			break;
		case 't':
			backtrace(excp);
			break;
		case 'f':
			cacheflush();
			break;
		case 'h':
			dump_hash_table();
			break;
		case 's':
		case 'x':
		case EOF:
			return cmd;
		case '?':
			printf(help_string);
			break;
		default:
			printf("Unrecognized command: ");
			if( ' ' < cmd && cmd <= '~' )
				putchar(cmd);
			else
				printf("\\x%x", cmd);
			printf(" (type ? for help)\n");
			break;
		case 'b':
			bpt_cmds();
			break;
		case 'C':
			csum();
			break;
#ifdef CONFIG_SMP
		case 'c':
			cpu_cmd();
			break;
#endif /* CONFIG_SMP */
		}
	}
}

#ifdef CONFIG_SMP
static void cpu_cmd(void)
{
	unsigned cpu;
	int timeout;
	int cmd;

	cmd = inchar();
	if (cmd == 'i') {
		/* interrupt other cpu(s) */
		cpu = MSG_ALL_BUT_SELF;
		scanhex(&cpu);
		smp_send_xmon_break(cpu);
		return;
	}
	termch = cmd;
	if (!scanhex(&cpu)) {
		/* print cpus waiting or in xmon */
		printf("cpus stopped:");
		for (cpu = 0; cpu < NR_CPUS; ++cpu) {
			if (test_bit(cpu, &cpus_in_xmon)) {
				printf(" %d", cpu);
				if (cpu == smp_processor_id())
					printf("*", cpu);
			}
		}
		printf("\n");
		return;
	}
	/* try to switch to cpu specified */
	take_xmon = cpu;
	timeout = 10000000;
	while (take_xmon >= 0) {
		if (--timeout == 0) {
			/* yes there's a race here */
			take_xmon = -1;
			printf("cpu %u didn't take control\n", cpu);
			return;
		}
	}
	/* now have to wait to be given control back */
	while (test_and_set_bit(0, &got_xmon)) {
		if (take_xmon == smp_processor_id()) {
			take_xmon = -1;
			break;
		}
	}
}
#endif /* CONFIG_SMP */

static unsigned short fcstab[256] = {
	0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf,
	0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7,
	0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e,
	0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876,
	0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd,
	0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5,
	0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c,
	0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974,
	0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb,
	0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3,
	0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a,
	0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72,
	0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9,
	0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1,
	0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738,
	0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70,
	0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7,
	0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff,
	0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036,
	0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e,
	0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5,
	0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd,
	0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134,
	0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c,
	0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3,
	0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb,
	0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232,
	0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a,
	0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1,
	0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9,
	0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330,
	0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78
};

#define FCS(fcs, c)	(((fcs) >> 8) ^ fcstab[((fcs) ^ (c)) & 0xff])

static void
csum(void)
{
	unsigned int i;
	unsigned short fcs;
	unsigned char v;

	scanhex(&adrs);
	scanhex(&ncsum);
	fcs = 0xffff;
	for (i = 0; i < ncsum; ++i) {
		if (mread(adrs+i, &v, 1) == 0) {
			printf("csum stopped at %x\n", adrs+i);
			break;
		}
		fcs = FCS(fcs, v);
	}
	printf("%x\n", fcs);
}

static void
bpt_cmds(void)
{
	int cmd;