[mirror_ubuntu-zesty-kernel.git] / arch / frv / kernel / debug-stub.c

/* debug-stub.c: debug-mode stub
 *
 * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */

#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/init.h>
#include <linux/serial_reg.h>

#include <asm/system.h>
#include <asm/serial-regs.h>
#include <asm/timer-regs.h>
#include <asm/irc-regs.h>
#include <asm/gdb-stub.h>
#include "gdb-io.h"

/* CPU board CON5 */
#define __UART0(X) (*(volatile uint8_t *)(UART0_BASE + (UART_##X)))

#define LSR_WAIT_FOR0(STATE)			\
do {						\
} while (!(__UART0(LSR) & UART_LSR_##STATE))

#define FLOWCTL_QUERY0(LINE)	({ __UART0(MSR) & UART_MSR_##LINE; })
#define FLOWCTL_CLEAR0(LINE)	do { __UART0(MCR) &= ~UART_MCR_##LINE; } while (0)
#define FLOWCTL_SET0(LINE)	do { __UART0(MCR) |= UART_MCR_##LINE; } while (0)

#define FLOWCTL_WAIT_FOR0(LINE)			\
do {						\
	gdbstub_do_rx();			\
} while(!FLOWCTL_QUERY(LINE))

static void __init debug_stub_init(void);

extern asmlinkage void __break_hijack_kernel_event(void);
extern asmlinkage void __break_hijack_kernel_event_breaks_here(void);

/*****************************************************************************/
/*
 * debug mode handler stub
 * - we come here with the CPU in debug mode and with exceptions disabled
 * - handle debugging services for userspace
 */
asmlinkage void debug_stub(void)
{
	unsigned long hsr0;
	int type = 0;

	static u8 inited = 0;
	if (!inited) {
		debug_stub_init();
		type = -1;
		inited = 1;
	}

	hsr0 = __get_HSR(0);
	if (hsr0 & HSR0_ETMD)
		__set_HSR(0, hsr0 & ~HSR0_ETMD);

	/* disable single stepping */
	__debug_regs->dcr &= ~DCR_SE;

	/* kernel mode can propose an exception be handled in debug mode by jumping to a special
	 * location */
	if (__debug_frame->pc == (unsigned long) __break_hijack_kernel_event_breaks_here) {
		/* replace the debug frame with the kernel frame and discard
		 * the top kernel context */
		*__debug_frame = *__frame;
		__frame = __debug_frame->next_frame;
		__debug_regs->brr = (__debug_frame->tbr & TBR_TT) << 12;
		__debug_regs->brr |= BRR_EB;
	}

	if (__debug_frame->pc == (unsigned long) __debug_bug_trap + 4) {
		__debug_frame->pc = __debug_frame->lr;
		type = __debug_frame->gr8;
	}

#ifdef CONFIG_GDBSTUB
	gdbstub(type);
#endif

	if (hsr0 & HSR0_ETMD)
		__set_HSR(0, __get_HSR(0) | HSR0_ETMD);

} /* end debug_stub() */

/*****************************************************************************/
/*
 * debug stub initialisation
 */
static void __init debug_stub_init(void)
{
	__set_IRR(6, 0xff000000);	/* map ERRs to NMI */
	__set_IITMR(1, 0x20000000);	/* ERR0/1, UART0/1 IRQ detect levels */

	asm volatile("	movgs	gr0,ibar0	\n"
		     "	movgs	gr0,ibar1	\n"
		     "	movgs	gr0,ibar2	\n"
		     "	movgs	gr0,ibar3	\n"
		     "	movgs	gr0,dbar0	\n"
		     "	movgs	gr0,dbmr00	\n"
		     "	movgs	gr0,dbmr01	\n"
		     "	movgs	gr0,dbdr00	\n"
		     "	movgs	gr0,dbdr01	\n"
		     "	movgs	gr0,dbar1	\n"
		     "	movgs	gr0,dbmr10	\n"
		     "	movgs	gr0,dbmr11	\n"
		     "	movgs	gr0,dbdr10	\n"
		     "	movgs	gr0,dbdr11	\n"
		     );

	/* deal with debugging stub initialisation and initial pause */
	if (__debug_frame->pc == (unsigned long) __debug_stub_init_break)
		__debug_frame->pc = (unsigned long) start_kernel;

	/* enable the debug events we want to trap */
	__debug_regs->dcr = DCR_EBE;

#ifdef CONFIG_GDBSTUB
	gdbstub_init();
#endif

	__clr_MASK_all();
	__clr_MASK(15);
	__clr_RC(15);

} /* end debug_stub_init() */

/*****************************************************************************/
/*
 * kernel "exit" trap for gdb stub
 */
void debug_stub_exit(int status)
{

#ifdef CONFIG_GDBSTUB
	gdbstub_exit(status);
#endif

} /* end debug_stub_exit() */

/*****************************************************************************/
/*
 * send string to serial port
 */
void debug_to_serial(const char *p, int n)
{
	char ch;

	for (; n > 0; n--) {
		ch = *p++;
		FLOWCTL_SET0(DTR);
		LSR_WAIT_FOR0(THRE);
		// FLOWCTL_WAIT_FOR(CTS);

		if (ch == 0x0a) {
			__UART0(TX) = 0x0d;
			mb();
			LSR_WAIT_FOR0(THRE);
			// FLOWCTL_WAIT_FOR(CTS);
		}
		__UART0(TX) = ch;
		mb();

		FLOWCTL_CLEAR0(DTR);
	}

} /* end debug_to_serial() */

/*****************************************************************************/
/*
 * send string to serial port
 */
void debug_to_serial2(const char *fmt, ...)
{
	va_list va;
	char buf[64];
	int n;

	va_start(va, fmt);
	n = vsprintf(buf, fmt, va);
	va_end(va);

	debug_to_serial(buf, n);

} /* end debug_to_serial2() */

/*****************************************************************************/
/*
 * set up the ttyS0 serial port baud rate timers
 */
void __init console_set_baud(unsigned baud)
{
	unsigned value, high, low;
	u8 lcr;

	/* work out the divisor to give us the nearest higher baud rate */
	value = __serial_clock_speed_HZ / 16 / baud;

	/* determine the baud rate range */
	high = __serial_clock_speed_HZ / 16 / value;
	low = __serial_clock_speed_HZ / 16 / (value + 1);

	/* pick the nearest bound */
	if (low + (high - low) / 2 > baud)
		value++;

	lcr = __UART0(LCR);
	__UART0(LCR) |= UART_LCR_DLAB;
	mb();
	__UART0(DLL) = value & 0xff;
	__UART0(DLM) = (value >> 8) & 0xff;
	mb();
	__UART0(LCR) = lcr;
	mb();

} /* end console_set_baud() */

/*****************************************************************************/
/*
 *
 */
int __init console_get_baud(void)
{
	unsigned value;
	u8 lcr;

	lcr = __UART0(LCR);
	__UART0(LCR) |= UART_LCR_DLAB;
	mb();
	value =  __UART0(DLM) << 8;
	value |= __UART0(DLL);
	__UART0(LCR) = lcr;
	mb();

	return value;
} /* end console_get_baud() */

/*****************************************************************************/
/*
 * display BUG() info
 */
#ifndef CONFIG_NO_KERNEL_MSG
void __debug_bug_printk(const char *file, unsigned line)
{
	printk("kernel BUG at %s:%d!\n", file, line);

} /* end __debug_bug_printk() */
#endif
Commit	Line	Data
1da177e4 LT	1	/* debug-stub.c: debug-mode stub
	2	*
	3	* Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
	4	* Written by David Howells (dhowells@redhat.com)
	5	*
	6	* This program is free software; you can redistribute it and/or
	7	* modify it under the terms of the GNU General Public License
	8	* as published by the Free Software Foundation; either version
	9	* 2 of the License, or (at your option) any later version.
	10	*/
	11
	12	#include <linux/string.h>
	13	#include <linux/kernel.h>
	14	#include <linux/signal.h>
	15	#include <linux/sched.h>
	16	#include <linux/init.h>
	17	#include <linux/serial_reg.h>
	18
	19	#include <asm/system.h>
	20	#include <asm/serial-regs.h>
	21	#include <asm/timer-regs.h>
	22	#include <asm/irc-regs.h>
	23	#include <asm/gdb-stub.h>
	24	#include "gdb-io.h"
	25
	26	/* CPU board CON5 */
	27	#define __UART0(X) ((volatile uint8_t )(UART0_BASE + (UART_##X)))
	28
	29	#define LSR_WAIT_FOR0(STATE) \
	30	do { \
	31	} while (!(__UART0(LSR) & UART_LSR_##STATE))
	32
	33	#define FLOWCTL_QUERY0(LINE) ({ __UART0(MSR) & UART_MSR_##LINE; })
	34	#define FLOWCTL_CLEAR0(LINE) do { __UART0(MCR) &= ~UART_MCR_##LINE; } while (0)
	35	#define FLOWCTL_SET0(LINE) do { __UART0(MCR) \|= UART_MCR_##LINE; } while (0)
	36
	37	#define FLOWCTL_WAIT_FOR0(LINE) \
	38	do { \
	39	gdbstub_do_rx(); \
	40	} while(!FLOWCTL_QUERY(LINE))
	41
	42	static void __init debug_stub_init(void);
	43
	44	extern asmlinkage void __break_hijack_kernel_event(void);
	45	extern asmlinkage void __break_hijack_kernel_event_breaks_here(void);
	46
	47	/*****************************************************************************/
	48	/*
	49	* debug mode handler stub
	50	* - we come here with the CPU in debug mode and with exceptions disabled
	51	* - handle debugging services for userspace
	52	*/
	53	asmlinkage void debug_stub(void)
	54	{
	55	unsigned long hsr0;
	56	int type = 0;
	57
	58	static u8 inited = 0;
	59	if (!inited) {
	60	debug_stub_init();
	61	type = -1;
	62	inited = 1;
	63	}
	64
65	hsr0 = __get_HSR(0);
66	if (hsr0 & HSR0_ETMD)
67	__set_HSR(0, hsr0 & ~HSR0_ETMD);
68
69	/* disable single stepping */
70	__debug_regs->dcr &= ~DCR_SE;
71
72	/* kernel mode can propose an exception be handled in debug mode by jumping to a special
73	* location */
74	if (__debug_frame->pc == (unsigned long) __break_hijack_kernel_event_breaks_here) {
75	/* replace the debug frame with the kernel frame and discard
76	* the top kernel context */
77	__debug_frame = __frame;
78	__frame = __debug_frame->next_frame;
79	__debug_regs->brr = (__debug_frame->tbr & TBR_TT) << 12;
80	__debug_regs->brr \|= BRR_EB;
81	}
82
83	if (__debug_frame->pc == (unsigned long) __debug_bug_trap + 4) {
84	__debug_frame->pc = __debug_frame->lr;
85	type = __debug_frame->gr8;
86	}
87
88	#ifdef CONFIG_GDBSTUB
89	gdbstub(type);
90	#endif
91
92	if (hsr0 & HSR0_ETMD)
93	__set_HSR(0, __get_HSR(0) \| HSR0_ETMD);
94
95	} /* end debug_stub() */
96
97	/*****************************************************************************/
98	/*
99	* debug stub initialisation
100	*/
101	static void __init debug_stub_init(void)
102	{
103	__set_IRR(6, 0xff000000); /* map ERRs to NMI */
104	__set_IITMR(1, 0x20000000); /* ERR0/1, UART0/1 IRQ detect levels */
105
106	asm volatile(" movgs gr0,ibar0 \n"
107	" movgs gr0,ibar1 \n"
108	" movgs gr0,ibar2 \n"
109	" movgs gr0,ibar3 \n"
110	" movgs gr0,dbar0 \n"
111	" movgs gr0,dbmr00 \n"
112	" movgs gr0,dbmr01 \n"
113	" movgs gr0,dbdr00 \n"
114	" movgs gr0,dbdr01 \n"
115	" movgs gr0,dbar1 \n"
116	" movgs gr0,dbmr10 \n"
117	" movgs gr0,dbmr11 \n"
118	" movgs gr0,dbdr10 \n"
119	" movgs gr0,dbdr11 \n"
120	);
121
122	/* deal with debugging stub initialisation and initial pause */
123	if (__debug_frame->pc == (unsigned long) __debug_stub_init_break)
124	__debug_frame->pc = (unsigned long) start_kernel;
125
126	/* enable the debug events we want to trap */
127	__debug_regs->dcr = DCR_EBE;
128
129	#ifdef CONFIG_GDBSTUB
130	gdbstub_init();
131	#endif
132
133	__clr_MASK_all();
134	__clr_MASK(15);
135	__clr_RC(15);
136
137	} /* end debug_stub_init() */
138
139	/*****************************************************************************/
140	/*
141	* kernel "exit" trap for gdb stub
142	*/
143	void debug_stub_exit(int status)
144	{
145
146	#ifdef CONFIG_GDBSTUB
147	gdbstub_exit(status);
148	#endif
149
150	} /* end debug_stub_exit() */
151
152	/*****************************************************************************/
153	/*
154	* send string to serial port
155	*/
156	void debug_to_serial(const char *p, int n)
157	{
158	char ch;
159
160	for (; n > 0; n--) {
161	ch = *p++;
162	FLOWCTL_SET0(DTR);
163	LSR_WAIT_FOR0(THRE);
164	// FLOWCTL_WAIT_FOR(CTS);
165
166	if (ch == 0x0a) {
167	__UART0(TX) = 0x0d;
168	mb();
169	LSR_WAIT_FOR0(THRE);
170	// FLOWCTL_WAIT_FOR(CTS);
171	}
172	__UART0(TX) = ch;
173	mb();
174
175	FLOWCTL_CLEAR0(DTR);
176	}
177
178	} /* end debug_to_serial() */
179
180	/*****************************************************************************/
181	/*
182	* send string to serial port
183	*/
184	void debug_to_serial2(const char *fmt, ...)
185	{
186	va_list va;
187	char buf[64];
188	int n;
189
190	va_start(va, fmt);
191	n = vsprintf(buf, fmt, va);
192	va_end(va);
193
194	debug_to_serial(buf, n);
195
196	} /* end debug_to_serial2() */
197
198	/*****************************************************************************/
199	/*
200	* set up the ttyS0 serial port baud rate timers
201	*/
202	void __init console_set_baud(unsigned baud)
203	{
204	unsigned value, high, low;
205	u8 lcr;
206
207	/* work out the divisor to give us the nearest higher baud rate */
208	value = __serial_clock_speed_HZ / 16 / baud;
209
210	/* determine the baud rate range */
211	high = __serial_clock_speed_HZ / 16 / value;
212	low = __serial_clock_speed_HZ / 16 / (value + 1);
213
214	/* pick the nearest bound */
215	if (low + (high - low) / 2 > baud)
216	value++;
217
218	lcr = __UART0(LCR);
219	__UART0(LCR) \|= UART_LCR_DLAB;
220	mb();
221	__UART0(DLL) = value & 0xff;
222	__UART0(DLM) = (value >> 8) & 0xff;
223	mb();
224	__UART0(LCR) = lcr;
225	mb();
226
227	} /* end console_set_baud() */
228
229	/*****************************************************************************/
230	/*
231	*
232	*/
233	int __init console_get_baud(void)
234	{
235	unsigned value;
236	u8 lcr;
237
238	lcr = __UART0(LCR);
239	__UART0(LCR) \|= UART_LCR_DLAB;
240	mb();
241	value = __UART0(DLM) << 8;
242	value \|= __UART0(DLL);
243	__UART0(LCR) = lcr;
244	mb();
245
246	return value;
247	} /* end console_get_baud() */
248
249	/*****************************************************************************/
250	/*
251	* display BUG() info
252	*/
253	#ifndef CONFIG_NO_KERNEL_MSG
254	void __debug_bug_printk(const char *file, unsigned line)
255	{
256	printk("kernel BUG at %s:%d!\n", file, line);
257
258	} /* end __debug_bug_printk() */
259	#endif