[mirror_ubuntu-artful-kernel.git] / arch / hexagon / kernel / traps.c

/*
 * Kernel traps/events for Hexagon processor
 *
 * Copyright (c) 2010-2014, The Linux Foundation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 and
 * only version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 */

#include <linux/init.h>
#include <linux/sched/signal.h>
#include <linux/module.h>
#include <linux/kallsyms.h>
#include <linux/kdebug.h>
#include <linux/syscalls.h>
#include <linux/signal.h>
#include <linux/tracehook.h>
#include <asm/traps.h>
#include <asm/vm_fault.h>
#include <asm/syscall.h>
#include <asm/registers.h>
#include <asm/unistd.h>
#include <asm/sections.h>
#ifdef CONFIG_KGDB
# include <linux/kgdb.h>
#endif

#define TRAP_SYSCALL	1
#define TRAP_DEBUG	0xdb

void __init trap_init(void)
{
}

#ifdef CONFIG_GENERIC_BUG
/* Maybe should resemble arch/sh/kernel/traps.c ?? */
int is_valid_bugaddr(unsigned long addr)
{
	return 1;
}
#endif /* CONFIG_GENERIC_BUG */

static const char *ex_name(int ex)
{
	switch (ex) {
	case HVM_GE_C_XPROT:
	case HVM_GE_C_XUSER:
		return "Execute protection fault";
	case HVM_GE_C_RPROT:
	case HVM_GE_C_RUSER:
		return "Read protection fault";
	case HVM_GE_C_WPROT:
	case HVM_GE_C_WUSER:
		return "Write protection fault";
	case HVM_GE_C_XMAL:
		return "Misaligned instruction";
	case HVM_GE_C_WREG:
		return "Multiple writes to same register in packet";
	case HVM_GE_C_PCAL:
		return "Program counter values that are not properly aligned";
	case HVM_GE_C_RMAL:
		return "Misaligned data load";
	case HVM_GE_C_WMAL:
		return "Misaligned data store";
	case HVM_GE_C_INVI:
	case HVM_GE_C_PRIVI:
		return "Illegal instruction";
	case HVM_GE_C_BUS:
		return "Precise bus error";
	case HVM_GE_C_CACHE:
		return "Cache error";

	case 0xdb:
		return "Debugger trap";

	default:
		return "Unrecognized exception";
	}
}

static void do_show_stack(struct task_struct *task, unsigned long *fp,
			  unsigned long ip)
{
	int kstack_depth_to_print = 24;
	unsigned long offset, size;
	const char *name = NULL;
	unsigned long *newfp;
	unsigned long low, high;
	char tmpstr[128];
	char *modname;
	int i;

	if (task == NULL)
		task = current;

	printk(KERN_INFO "CPU#%d, %s/%d, Call Trace:\n",
	       raw_smp_processor_id(), task->comm,
	       task_pid_nr(task));

	if (fp == NULL) {
		if (task == current) {
			asm("%0 = r30" : "=r" (fp));
		} else {
			fp = (unsigned long *)
			     ((struct hexagon_switch_stack *)
			     task->thread.switch_sp)->fp;
		}
	}

	if ((((unsigned long) fp) & 0x3) || ((unsigned long) fp < 0x1000)) {
		printk(KERN_INFO "-- Corrupt frame pointer %p\n", fp);
		return;
	}

	/* Saved link reg is one word above FP */
	if (!ip)
		ip = *(fp+1);

	/* Expect kernel stack to be in-bounds */
	low = (unsigned long)task_stack_page(task);
	high = low + THREAD_SIZE - 8;
	low += sizeof(struct thread_info);

	for (i = 0; i < kstack_depth_to_print; i++) {

		name = kallsyms_lookup(ip, &size, &offset, &modname, tmpstr);

		printk(KERN_INFO "[%p] 0x%lx: %s + 0x%lx", fp, ip, name,
			offset);
		if (((unsigned long) fp < low) || (high < (unsigned long) fp))
			printk(KERN_CONT " (FP out of bounds!)");
		if (modname)
			printk(KERN_CONT " [%s] ", modname);
		printk(KERN_CONT "\n");

		newfp = (unsigned long *) *fp;

		if (((unsigned long) newfp) & 0x3) {
			printk(KERN_INFO "-- Corrupt frame pointer %p\n",
				newfp);
			break;
		}

		/* Attempt to continue past exception. */
		if (0 == newfp) {
			struct pt_regs *regs = (struct pt_regs *) (((void *)fp)
						+ 8);

			if (regs->syscall_nr != -1) {
				printk(KERN_INFO "-- trap0 -- syscall_nr: %ld",
					regs->syscall_nr);
				printk(KERN_CONT "  psp: %lx  elr: %lx\n",
					 pt_psp(regs), pt_elr(regs));
				break;
			} else {
				/* really want to see more ... */
				kstack_depth_to_print += 6;
				printk(KERN_INFO "-- %s (0x%lx)  badva: %lx\n",
					ex_name(pt_cause(regs)), pt_cause(regs),
					pt_badva(regs));
			}

			newfp = (unsigned long *) regs->r30;
			ip = pt_elr(regs);
		} else {
			ip = *(newfp + 1);
		}

		/* If link reg is null, we are done. */
		if (ip == 0x0)
			break;

		/* If newfp isn't larger, we're tracing garbage. */
		if (newfp > fp)
			fp = newfp;
		else
			break;
	}
}

void show_stack(struct task_struct *task, unsigned long *fp)
{
	/* Saved link reg is one word above FP */
	do_show_stack(task, fp, 0);
}

int die(const char *str, struct pt_regs *regs, long err)
{
	static struct {
		spinlock_t lock;
		int counter;
	} die = {
		.lock = __SPIN_LOCK_UNLOCKED(die.lock),
		.counter = 0
	};

	console_verbose();
	oops_enter();

	spin_lock_irq(&die.lock);
	bust_spinlocks(1);
	printk(KERN_EMERG "Oops: %s[#%d]:\n", str, ++die.counter);

	if (notify_die(DIE_OOPS, str, regs, err, pt_cause(regs), SIGSEGV) ==
	    NOTIFY_STOP)
		return 1;

	print_modules();
	show_regs(regs);
	do_show_stack(current, &regs->r30, pt_elr(regs));

	bust_spinlocks(0);
	add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);

	spin_unlock_irq(&die.lock);

	if (in_interrupt())
		panic("Fatal exception in interrupt");

	if (panic_on_oops)
		panic("Fatal exception");

	oops_exit();
	do_exit(err);
	return 0;
}

int die_if_kernel(char *str, struct pt_regs *regs, long err)
{
	if (!user_mode(regs))
		return die(str, regs, err);
	else
		return 0;
}

/*
 * It's not clear that misaligned fetches are ever recoverable.
 */
static void misaligned_instruction(struct pt_regs *regs)
{
	die_if_kernel("Misaligned Instruction", regs, 0);
	force_sig(SIGBUS, current);
}

/*
 * Misaligned loads and stores, on the other hand, can be
 * emulated, and probably should be, some day.  But for now
 * they will be considered fatal.
 */
static void misaligned_data_load(struct pt_regs *regs)
{
	die_if_kernel("Misaligned Data Load", regs, 0);
	force_sig(SIGBUS, current);
}

static void misaligned_data_store(struct pt_regs *regs)
{
	die_if_kernel("Misaligned Data Store", regs, 0);
	force_sig(SIGBUS, current);
}

static void illegal_instruction(struct pt_regs *regs)
{
	die_if_kernel("Illegal Instruction", regs, 0);
	force_sig(SIGILL, current);
}

/*
 * Precise bus errors may be recoverable with a a retry,
 * but for now, treat them as irrecoverable.
 */
static void precise_bus_error(struct pt_regs *regs)
{
	die_if_kernel("Precise Bus Error", regs, 0);
	force_sig(SIGBUS, current);
}

/*
 * If anything is to be done here other than panic,
 * it will probably be complex and migrate to another
 * source module.  For now, just die.
 */
static void cache_error(struct pt_regs *regs)
{
	die("Cache Error", regs, 0);
}

/*
 * General exception handler
 */
void do_genex(struct pt_regs *regs)
{
	/*
	 * Decode Cause and Dispatch
	 */
	switch (pt_cause(regs)) {
	case HVM_GE_C_XPROT:
	case HVM_GE_C_XUSER:
		execute_protection_fault(regs);
		break;
	case HVM_GE_C_RPROT:
	case HVM_GE_C_RUSER:
		read_protection_fault(regs);
		break;
	case HVM_GE_C_WPROT:
	case HVM_GE_C_WUSER:
		write_protection_fault(regs);
		break;
	case HVM_GE_C_XMAL:
		misaligned_instruction(regs);
		break;
	case HVM_GE_C_WREG:
		illegal_instruction(regs);
		break;
	case HVM_GE_C_PCAL:
		misaligned_instruction(regs);
		break;
	case HVM_GE_C_RMAL:
		misaligned_data_load(regs);
		break;
	case HVM_GE_C_WMAL:
		misaligned_data_store(regs);
		break;
	case HVM_GE_C_INVI:
	case HVM_GE_C_PRIVI:
		illegal_instruction(regs);
		break;
	case HVM_GE_C_BUS:
		precise_bus_error(regs);
		break;
	case HVM_GE_C_CACHE:
		cache_error(regs);
		break;
	default:
		/* Halt and catch fire */
		panic("Unrecognized exception 0x%lx\n", pt_cause(regs));
		break;
	}
}

/* Indirect system call dispatch */
long sys_syscall(void)
{
	printk(KERN_ERR "sys_syscall invoked!\n");
	return -ENOSYS;
}

void do_trap0(struct pt_regs *regs)
{
	syscall_fn syscall;

	switch (pt_cause(regs)) {
	case TRAP_SYSCALL:
		/* System call is trap0 #1 */

		/* allow strace to catch syscall args  */
		if (unlikely(test_thread_flag(TIF_SYSCALL_TRACE) &&
			tracehook_report_syscall_entry(regs)))
			return;  /*  return -ENOSYS somewhere?  */

		/* Interrupts should be re-enabled for syscall processing */
		__vmsetie(VM_INT_ENABLE);

		/*
		 * System call number is in r6, arguments in r0..r5.
		 * Fortunately, no Linux syscall has more than 6 arguments,
		 * and Hexagon ABI passes first 6 arguments in registers.
		 * 64-bit arguments are passed in odd/even register pairs.
		 * Fortunately, we have no system calls that take more
		 * than three arguments with more than one 64-bit value.
		 * Should that change, we'd need to redesign to copy
		 * between user and kernel stacks.
		 */
		regs->syscall_nr = regs->r06;

		/*
		 * GPR R0 carries the first parameter, and is also used
		 * to report the return value.  We need a backup of
		 * the user's value in case we need to do a late restart
		 * of the system call.
		 */
		regs->restart_r0 = regs->r00;

		if ((unsigned long) regs->syscall_nr >= __NR_syscalls) {
			regs->r00 = -1;
		} else {
			syscall = (syscall_fn)
				  (sys_call_table[regs->syscall_nr]);
			regs->r00 = syscall(regs->r00, regs->r01,
				   regs->r02, regs->r03,
				   regs->r04, regs->r05);
		}

		/* allow strace to get the syscall return state  */
		if (unlikely(test_thread_flag(TIF_SYSCALL_TRACE)))
			tracehook_report_syscall_exit(regs, 0);

		break;
	case TRAP_DEBUG:
		/* Trap0 0xdb is debug breakpoint */
		if (user_mode(regs)) {
			struct siginfo info;

			info.si_signo = SIGTRAP;
			info.si_errno = 0;
			/*
			 * Some architecures add some per-thread state
			 * to distinguish between breakpoint traps and
			 * trace traps.  We may want to do that, and
			 * set the si_code value appropriately, or we
			 * may want to use a different trap0 flavor.
			 */
			info.si_code = TRAP_BRKPT;
			info.si_addr = (void __user *) pt_elr(regs);
			force_sig_info(SIGTRAP, &info, current);
		} else {
#ifdef CONFIG_KGDB
			kgdb_handle_exception(pt_cause(regs), SIGTRAP,
					      TRAP_BRKPT, regs);
#endif
		}
		break;
	}
	/* Ignore other trap0 codes for now, especially 0 (Angel calls) */
}

/*
 * Machine check exception handler
 */
void do_machcheck(struct pt_regs *regs)
{
	/* Halt and catch fire */
	__vmstop();
}

/*
 * Treat this like the old 0xdb trap.
 */

void do_debug_exception(struct pt_regs *regs)
{
	regs->hvmer.vmest &= ~HVM_VMEST_CAUSE_MSK;
	regs->hvmer.vmest |= (TRAP_DEBUG << HVM_VMEST_CAUSE_SFT);
	do_trap0(regs);
}
Commit	Line	Data
cf9750ba RK	1	/*
	2	* Kernel traps/events for Hexagon processor
	3	*
8914d7e8	4	* Copyright (c) 2010-2014, The Linux Foundation. All rights reserved.
cf9750ba RK	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License version 2 and
	8	* only version 2 as published by the Free Software Foundation.
	9	*
	10	* This program is distributed in the hope that it will be useful,
	11	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	13	* GNU General Public License for more details.
	14	*
	15	* You should have received a copy of the GNU General Public License
	16	* along with this program; if not, write to the Free Software
	17	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
	18	* 02110-1301, USA.
	19	*/
	20
	21	#include <linux/init.h>
3f07c014	22	#include <linux/sched/signal.h>
cf9750ba RK	23	#include <linux/module.h>
	24	#include <linux/kallsyms.h>
	25	#include <linux/kdebug.h>
	26	#include <linux/syscalls.h>
	27	#include <linux/signal.h>
	28	#include <linux/tracehook.h>
	29	#include <asm/traps.h>
	30	#include <asm/vm_fault.h>
	31	#include <asm/syscall.h>
	32	#include <asm/registers.h>
	33	#include <asm/unistd.h>
	34	#include <asm/sections.h>
	35	#ifdef CONFIG_KGDB
	36	# include <linux/kgdb.h>
	37	#endif
	38
	39	#define TRAP_SYSCALL 1
	40	#define TRAP_DEBUG 0xdb
	41
	42	void __init trap_init(void)
	43	{
	44	}
	45
	46	#ifdef CONFIG_GENERIC_BUG
	47	/* Maybe should resemble arch/sh/kernel/traps.c ?? */
	48	int is_valid_bugaddr(unsigned long addr)
	49	{
	50	return 1;
	51	}
	52	#endif /* CONFIG_GENERIC_BUG */
	53
	54	static const char *ex_name(int ex)
	55	{
	56	switch (ex) {
	57	case HVM_GE_C_XPROT:
	58	case HVM_GE_C_XUSER:
	59	return "Execute protection fault";
	60	case HVM_GE_C_RPROT:
	61	case HVM_GE_C_RUSER:
	62	return "Read protection fault";
	63	case HVM_GE_C_WPROT:
	64	case HVM_GE_C_WUSER:
	65	return "Write protection fault";
	66	case HVM_GE_C_XMAL:
	67	return "Misaligned instruction";
db0fe532 RK	68	case HVM_GE_C_WREG:
	69	return "Multiple writes to same register in packet";
	70	case HVM_GE_C_PCAL:
	71	return "Program counter values that are not properly aligned";
cf9750ba RK	72	case HVM_GE_C_RMAL:
	73	return "Misaligned data load";
	74	case HVM_GE_C_WMAL:
	75	return "Misaligned data store";
	76	case HVM_GE_C_INVI:
	77	case HVM_GE_C_PRIVI:
	78	return "Illegal instruction";
	79	case HVM_GE_C_BUS:
	80	return "Precise bus error";
	81	case HVM_GE_C_CACHE:
	82	return "Cache error";
	83
	84	case 0xdb:
	85	return "Debugger trap";
	86
	87	default:
	88	return "Unrecognized exception";
	89	}
	90	}
	91
	92	static void do_show_stack(struct task_struct task, unsigned long fp,
	93	unsigned long ip)
	94	{
	95	int kstack_depth_to_print = 24;
	96	unsigned long offset, size;
	97	const char *name = NULL;
	98	unsigned long *newfp;
	99	unsigned long low, high;
	100	char tmpstr[128];
	101	char *modname;
	102	int i;
	103
	104	if (task == NULL)
	105	task = current;
	106
	107	printk(KERN_INFO "CPU#%d, %s/%d, Call Trace:\n",
	108	raw_smp_processor_id(), task->comm,
	109	task_pid_nr(task));
	110
	111	if (fp == NULL) {
	112	if (task == current) {
	113	asm("%0 = r30" : "=r" (fp));
	114	} else {
	115	fp = (unsigned long *)
	116	((struct hexagon_switch_stack *)
	117	task->thread.switch_sp)->fp;
	118	}
	119	}
	120
	121	if ((((unsigned long) fp) & 0x3) \|\| ((unsigned long) fp < 0x1000)) {
	122	printk(KERN_INFO "-- Corrupt frame pointer %p\n", fp);
	123	return;
	124	}
	125
	126	/* Saved link reg is one word above FP */
	127	if (!ip)
	128	ip = *(fp+1);
	129
	130	/* Expect kernel stack to be in-bounds */
	131	low = (unsigned long)task_stack_page(task);
	132	high = low + THREAD_SIZE - 8;
	133	low += sizeof(struct thread_info);
	134
	135	for (i = 0; i < kstack_depth_to_print; i++) {
136
137	name = kallsyms_lookup(ip, &size, &offset, &modname, tmpstr);
138
139	printk(KERN_INFO "[%p] 0x%lx: %s + 0x%lx", fp, ip, name,
140	offset);
141	if (((unsigned long) fp < low) \|\| (high < (unsigned long) fp))
142	printk(KERN_CONT " (FP out of bounds!)");
143	if (modname)
144	printk(KERN_CONT " [%s] ", modname);
145	printk(KERN_CONT "\n");
146
147	newfp = (unsigned long ) fp;
148
149	if (((unsigned long) newfp) & 0x3) {
150	printk(KERN_INFO "-- Corrupt frame pointer %p\n",
151	newfp);
152	break;
153	}
154
155	/* Attempt to continue past exception. */
156	if (0 == newfp) {
157	struct pt_regs regs = (struct pt_regs ) (((void *)fp)
158	+ 8);
159
160	if (regs->syscall_nr != -1) {
161	printk(KERN_INFO "-- trap0 -- syscall_nr: %ld",
162	regs->syscall_nr);
163	printk(KERN_CONT " psp: %lx elr: %lx\n",
164	pt_psp(regs), pt_elr(regs));
165	break;
166	} else {
167	/* really want to see more ... */
168	kstack_depth_to_print += 6;
169	printk(KERN_INFO "-- %s (0x%lx) badva: %lx\n",
170	ex_name(pt_cause(regs)), pt_cause(regs),
171	pt_badva(regs));
172	}
173
174	newfp = (unsigned long *) regs->r30;
175	ip = pt_elr(regs);
176	} else {
177	ip = *(newfp + 1);
178	}
179
180	/* If link reg is null, we are done. */
181	if (ip == 0x0)
182	break;
183
184	/* If newfp isn't larger, we're tracing garbage. */
185	if (newfp > fp)
186	fp = newfp;
187	else
188	break;
189	}
190	}
191
192	void show_stack(struct task_struct task, unsigned long fp)
193	{
194	/* Saved link reg is one word above FP */
195	do_show_stack(task, fp, 0);
196	}
197
cf9750ba RK	198	int die(const char str, struct pt_regs regs, long err)
	199	{
	200	static struct {
	201	spinlock_t lock;
	202	int counter;
	203	} die = {
	204	.lock = __SPIN_LOCK_UNLOCKED(die.lock),
	205	.counter = 0
	206	};
	207
	208	console_verbose();
	209	oops_enter();
	210
	211	spin_lock_irq(&die.lock);
	212	bust_spinlocks(1);
	213	printk(KERN_EMERG "Oops: %s[#%d]:\n", str, ++die.counter);
	214
	215	if (notify_die(DIE_OOPS, str, regs, err, pt_cause(regs), SIGSEGV) ==
	216	NOTIFY_STOP)
	217	return 1;
	218
	219	print_modules();
	220	show_regs(regs);
	221	do_show_stack(current, &regs->r30, pt_elr(regs));
	222
	223	bust_spinlocks(0);
373d4d09	224	add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
cf9750ba RK	225
	226	spin_unlock_irq(&die.lock);
	227
	228	if (in_interrupt())
	229	panic("Fatal exception in interrupt");
	230
	231	if (panic_on_oops)
	232	panic("Fatal exception");
	233
	234	oops_exit();
	235	do_exit(err);
	236	return 0;
	237	}
	238
	239	int die_if_kernel(char str, struct pt_regs regs, long err)
	240	{
	241	if (!user_mode(regs))
	242	return die(str, regs, err);
	243	else
	244	return 0;
	245	}
	246
	247	/*
	248	* It's not clear that misaligned fetches are ever recoverable.
	249	*/
	250	static void misaligned_instruction(struct pt_regs *regs)
	251	{
	252	die_if_kernel("Misaligned Instruction", regs, 0);
	253	force_sig(SIGBUS, current);
	254	}
	255
	256	/*
	257	* Misaligned loads and stores, on the other hand, can be
	258	* emulated, and probably should be, some day. But for now
	259	* they will be considered fatal.
	260	*/
	261	static void misaligned_data_load(struct pt_regs *regs)
	262	{
	263	die_if_kernel("Misaligned Data Load", regs, 0);
	264	force_sig(SIGBUS, current);
	265	}
	266
	267	static void misaligned_data_store(struct pt_regs *regs)
	268	{
	269	die_if_kernel("Misaligned Data Store", regs, 0);
	270	force_sig(SIGBUS, current);
	271	}
	272
	273	static void illegal_instruction(struct pt_regs *regs)
	274	{
	275	die_if_kernel("Illegal Instruction", regs, 0);
	276	force_sig(SIGILL, current);
	277	}
	278
	279	/*
	280	* Precise bus errors may be recoverable with a a retry,
	281	* but for now, treat them as irrecoverable.
	282	*/
	283	static void precise_bus_error(struct pt_regs *regs)
	284	{
	285	die_if_kernel("Precise Bus Error", regs, 0);
	286	force_sig(SIGBUS, current);
	287	}
	288
289	/*
290	* If anything is to be done here other than panic,
291	* it will probably be complex and migrate to another
292	* source module. For now, just die.
293	*/
294	static void cache_error(struct pt_regs *regs)
295	{
296	die("Cache Error", regs, 0);
297	}
298
299	/*
300	* General exception handler
301	*/
302	void do_genex(struct pt_regs *regs)
303	{
304	/*
305	* Decode Cause and Dispatch
306	*/
307	switch (pt_cause(regs)) {
308	case HVM_GE_C_XPROT:
309	case HVM_GE_C_XUSER:
310	execute_protection_fault(regs);
311	break;
312	case HVM_GE_C_RPROT:
313	case HVM_GE_C_RUSER:
314	read_protection_fault(regs);
315	break;
316	case HVM_GE_C_WPROT:
317	case HVM_GE_C_WUSER:
318	write_protection_fault(regs);
319	break;
320	case HVM_GE_C_XMAL:
321	misaligned_instruction(regs);
322	break;
db0fe532 RK	323	case HVM_GE_C_WREG:
	324	illegal_instruction(regs);
	325	break;
	326	case HVM_GE_C_PCAL:
	327	misaligned_instruction(regs);
	328	break;
cf9750ba RK	329	case HVM_GE_C_RMAL:
	330	misaligned_data_load(regs);
	331	break;
	332	case HVM_GE_C_WMAL:
	333	misaligned_data_store(regs);
	334	break;
	335	case HVM_GE_C_INVI:
	336	case HVM_GE_C_PRIVI:
	337	illegal_instruction(regs);
	338	break;
	339	case HVM_GE_C_BUS:
	340	precise_bus_error(regs);
	341	break;
	342	case HVM_GE_C_CACHE:
	343	cache_error(regs);
	344	break;
	345	default:
	346	/* Halt and catch fire */
	347	panic("Unrecognized exception 0x%lx\n", pt_cause(regs));
	348	break;
	349	}
	350	}
	351
	352	/* Indirect system call dispatch */
	353	long sys_syscall(void)
	354	{
	355	printk(KERN_ERR "sys_syscall invoked!\n");
	356	return -ENOSYS;
	357	}
	358
	359	void do_trap0(struct pt_regs *regs)
	360	{
cf9750ba RK	361	syscall_fn syscall;
	362
	363	switch (pt_cause(regs)) {
	364	case TRAP_SYSCALL:
	365	/* System call is trap0 #1 */
	366
	367	/* allow strace to catch syscall args */
	368	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACE) &&
	369	tracehook_report_syscall_entry(regs)))
	370	return; /* return -ENOSYS somewhere? */
	371
	372	/* Interrupts should be re-enabled for syscall processing */
	373	__vmsetie(VM_INT_ENABLE);
	374
	375	/*
	376	* System call number is in r6, arguments in r0..r5.
	377	* Fortunately, no Linux syscall has more than 6 arguments,
	378	* and Hexagon ABI passes first 6 arguments in registers.
	379	* 64-bit arguments are passed in odd/even register pairs.
	380	* Fortunately, we have no system calls that take more
	381	* than three arguments with more than one 64-bit value.
	382	* Should that change, we'd need to redesign to copy
	383	* between user and kernel stacks.
	384	*/
	385	regs->syscall_nr = regs->r06;
	386
	387	/*
	388	* GPR R0 carries the first parameter, and is also used
	389	* to report the return value. We need a backup of
	390	* the user's value in case we need to do a late restart
	391	* of the system call.
	392	*/
	393	regs->restart_r0 = regs->r00;
	394
	395	if ((unsigned long) regs->syscall_nr >= __NR_syscalls) {
	396	regs->r00 = -1;
	397	} else {
	398	syscall = (syscall_fn)
	399	(sys_call_table[regs->syscall_nr]);
a11e67c2	400	regs->r00 = syscall(regs->r00, regs->r01,
cf9750ba RK	401	regs->r02, regs->r03,
	402	regs->r04, regs->r05);
	403	}
	404
cf9750ba RK	405	/* allow strace to get the syscall return state */
	406	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACE)))
	407	tracehook_report_syscall_exit(regs, 0);
	408
	409	break;
	410	case TRAP_DEBUG:
	411	/* Trap0 0xdb is debug breakpoint */
	412	if (user_mode(regs)) {
	413	struct siginfo info;
	414
	415	info.si_signo = SIGTRAP;
	416	info.si_errno = 0;
	417	/*
	418	* Some architecures add some per-thread state
	419	* to distinguish between breakpoint traps and
	420	* trace traps. We may want to do that, and
	421	* set the si_code value appropriately, or we
	422	* may want to use a different trap0 flavor.
	423	*/
	424	info.si_code = TRAP_BRKPT;
	425	info.si_addr = (void __user *) pt_elr(regs);
8914d7e8	426	force_sig_info(SIGTRAP, &info, current);
cf9750ba RK	427	} else {
	428	#ifdef CONFIG_KGDB
	429	kgdb_handle_exception(pt_cause(regs), SIGTRAP,
	430	TRAP_BRKPT, regs);
	431	#endif
	432	}
	433	break;
	434	}
	435	/* Ignore other trap0 codes for now, especially 0 (Angel calls) */
	436	}
	437
	438	/*
	439	* Machine check exception handler
	440	*/
	441	void do_machcheck(struct pt_regs *regs)
	442	{
	443	/* Halt and catch fire */
	444	__vmstop();
	445	}
7777746c RK	446
	447	/*
	448	* Treat this like the old 0xdb trap.
	449	*/
	450
	451	void do_debug_exception(struct pt_regs *regs)
	452	{
	453	regs->hvmer.vmest &= ~HVM_VMEST_CAUSE_MSK;
	454	regs->hvmer.vmest \|= (TRAP_DEBUG << HVM_VMEST_CAUSE_SFT);
	455	do_trap0(regs);
	456	}