Merge commit 'kgdb/kgdb-next'

9 files changed, 551 insertions, 2 deletions

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 621b7d3b9324..355e50f1f23a 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -12,6 +12,7 @@ config ARM
 	select RTC_LIB
 	select SYS_SUPPORTS_APM_EMULATION
 	select HAVE_OPROFILE
+	select HAVE_ARCH_KGDB
 	select HAVE_KPROBES if (!XIP_KERNEL)
 	select HAVE_KRETPROBES if (HAVE_KPROBES)
 	select HAVE_FTRACE if (!XIP_KERNEL)
diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile
index eb9092ca8008..1d296fc8494e 100644
--- a/arch/arm/kernel/Makefile
+++ b/arch/arm/kernel/Makefile
@@ -28,6 +28,7 @@ obj-$(CONFIG_KPROBES)		+= kprobes.o kprobes-decode.o
 obj-$(CONFIG_ATAGS_PROC)	+= atags.o
 obj-$(CONFIG_OABI_COMPAT)	+= sys_oabi-compat.o
 obj-$(CONFIG_ARM_THUMBEE)	+= thumbee.o
+obj-$(CONFIG_KGDB)		+= kgdb.o
 
 obj-$(CONFIG_CRUNCH)		+= crunch.o crunch-bits.o
 AFLAGS_crunch-bits.o		:= -Wa,-mcpu=ep9312
diff --git a/arch/arm/kernel/kgdb.c b/arch/arm/kernel/kgdb.c
new file mode 100644
index 000000000000..ca8766e4637e
--- /dev/null
+++ b/arch/arm/kernel/kgdb.c
@@ -0,0 +1,201 @@
+/*
+ * arch/arm/kernel/kgdb.c
+ *
+ * ARM KGDB support
+ *
+ * Copyright (c) 2002-2004 MontaVista Software, Inc
+ * Copyright (c) 2008 Wind River Systems, Inc.
+ *
+ * Authors:  George Davis <davis_g@mvista.com>
+ *           Deepak Saxena <dsaxena@plexity.net>
+ */
+#include <linux/kgdb.h>
+#include <asm/traps.h>
+
+/* Make a local copy of the registers passed into the handler (bletch) */
+void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *kernel_regs)
+{
+	int regno;
+
+	/* Initialize all to zero. */
+	for (regno = 0; regno < GDB_MAX_REGS; regno++)
+		gdb_regs[regno] = 0;
+
+	gdb_regs[_R0]		= kernel_regs->ARM_r0;
+	gdb_regs[_R1]		= kernel_regs->ARM_r1;
+	gdb_regs[_R2]		= kernel_regs->ARM_r2;
+	gdb_regs[_R3]		= kernel_regs->ARM_r3;
+	gdb_regs[_R4]		= kernel_regs->ARM_r4;
+	gdb_regs[_R5]		= kernel_regs->ARM_r5;
+	gdb_regs[_R6]		= kernel_regs->ARM_r6;
+	gdb_regs[_R7]		= kernel_regs->ARM_r7;
+	gdb_regs[_R8]		= kernel_regs->ARM_r8;
+	gdb_regs[_R9]		= kernel_regs->ARM_r9;
+	gdb_regs[_R10]		= kernel_regs->ARM_r10;
+	gdb_regs[_FP]		= kernel_regs->ARM_fp;
+	gdb_regs[_IP]		= kernel_regs->ARM_ip;
+	gdb_regs[_SPT]		= kernel_regs->ARM_sp;
+	gdb_regs[_LR]		= kernel_regs->ARM_lr;
+	gdb_regs[_PC]		= kernel_regs->ARM_pc;
+	gdb_regs[_CPSR]		= kernel_regs->ARM_cpsr;
+}
+
+/* Copy local gdb registers back to kgdb regs, for later copy to kernel */
+void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *kernel_regs)
+{
+	kernel_regs->ARM_r0	= gdb_regs[_R0];
+	kernel_regs->ARM_r1	= gdb_regs[_R1];
+	kernel_regs->ARM_r2	= gdb_regs[_R2];
+	kernel_regs->ARM_r3	= gdb_regs[_R3];
+	kernel_regs->ARM_r4	= gdb_regs[_R4];
+	kernel_regs->ARM_r5	= gdb_regs[_R5];
+	kernel_regs->ARM_r6	= gdb_regs[_R6];
+	kernel_regs->ARM_r7	= gdb_regs[_R7];
+	kernel_regs->ARM_r8	= gdb_regs[_R8];
+	kernel_regs->ARM_r9	= gdb_regs[_R9];
+	kernel_regs->ARM_r10	= gdb_regs[_R10];
+	kernel_regs->ARM_fp	= gdb_regs[_FP];
+	kernel_regs->ARM_ip	= gdb_regs[_IP];
+	kernel_regs->ARM_sp	= gdb_regs[_SPT];
+	kernel_regs->ARM_lr	= gdb_regs[_LR];
+	kernel_regs->ARM_pc	= gdb_regs[_PC];
+	kernel_regs->ARM_cpsr	= gdb_regs[_CPSR];
+}
+
+void
+sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *task)
+{
+	struct pt_regs *thread_regs;
+	int regno;
+
+	/* Just making sure... */
+	if (task == NULL)
+		return;
+
+	/* Initialize to zero */
+	for (regno = 0; regno < GDB_MAX_REGS; regno++)
+		gdb_regs[regno] = 0;
+
+	/* Otherwise, we have only some registers from switch_to() */
+	thread_regs		= task_pt_regs(task);
+	gdb_regs[_R0]		= thread_regs->ARM_r0;
+	gdb_regs[_R1]		= thread_regs->ARM_r1;
+	gdb_regs[_R2]		= thread_regs->ARM_r2;
+	gdb_regs[_R3]		= thread_regs->ARM_r3;
+	gdb_regs[_R4]		= thread_regs->ARM_r4;
+	gdb_regs[_R5]		= thread_regs->ARM_r5;
+	gdb_regs[_R6]		= thread_regs->ARM_r6;
+	gdb_regs[_R7]		= thread_regs->ARM_r7;
+	gdb_regs[_R8]		= thread_regs->ARM_r8;
+	gdb_regs[_R9]		= thread_regs->ARM_r9;
+	gdb_regs[_R10]		= thread_regs->ARM_r10;
+	gdb_regs[_FP]		= thread_regs->ARM_fp;
+	gdb_regs[_IP]		= thread_regs->ARM_ip;
+	gdb_regs[_SPT]		= thread_regs->ARM_sp;
+	gdb_regs[_LR]		= thread_regs->ARM_lr;
+	gdb_regs[_PC]		= thread_regs->ARM_pc;
+	gdb_regs[_CPSR]		= thread_regs->ARM_cpsr;
+}
+
+static int compiled_break;
+
+int kgdb_arch_handle_exception(int exception_vector, int signo,
+			       int err_code, char *remcom_in_buffer,
+			       char *remcom_out_buffer,
+			       struct pt_regs *linux_regs)
+{
+	long addr;
+	char *ptr;
+
+	switch (remcom_in_buffer[0]) {
+	case 'D':
+	case 'k':
+	case 'c':
+		kgdb_contthread = NULL;
+
+		/*
+		 * Try to read optional parameter, pc unchanged if no parm.
+		 * If this was a compiled breakpoint, we need to move
+		 * to the next instruction or we will just breakpoint
+		 * over and over again.
+		 */
+		ptr = &remcom_in_buffer[1];
+		if (kgdb_hex2long(&ptr, &addr))
+			linux_regs->ARM_pc = addr;
+		else if (compiled_break == 1)
+			linux_regs->ARM_pc += 4;
+
+		compiled_break = 0;
+
+		return 0;
+	}
+
+	return -1;
+}
+
+static int kgdb_brk_fn(struct pt_regs *regs, unsigned int instr)
+{
+	kgdb_handle_exception(1, SIGTRAP, 0, regs);
+
+	return 0;
+}
+
+static int kgdb_compiled_brk_fn(struct pt_regs *regs, unsigned int instr)
+{
+	compiled_break = 1;
+	kgdb_handle_exception(1, SIGTRAP, 0, regs);
+
+	return 0;
+}
+
+static struct undef_hook kgdb_brkpt_hook = {
+	.instr_mask		= 0xffffffff,
+	.instr_val		= KGDB_BREAKINST,
+	.fn			= kgdb_brk_fn
+};
+
+static struct undef_hook kgdb_compiled_brkpt_hook = {
+	.instr_mask		= 0xffffffff,
+	.instr_val		= KGDB_COMPILED_BREAK,
+	.fn			= kgdb_compiled_brk_fn
+};
+
+/**
+ *	kgdb_arch_init - Perform any architecture specific initalization.
+ *
+ *	This function will handle the initalization of any architecture
+ *	specific callbacks.
+ */
+int kgdb_arch_init(void)
+{
+	register_undef_hook(&kgdb_brkpt_hook);
+	register_undef_hook(&kgdb_compiled_brkpt_hook);
+
+	return 0;
+}
+
+/**
+ *	kgdb_arch_exit - Perform any architecture specific uninitalization.
+ *
+ *	This function will handle the uninitalization of any architecture
+ *	specific callbacks, for dynamic registration and unregistration.
+ */
+void kgdb_arch_exit(void)
+{
+	unregister_undef_hook(&kgdb_brkpt_hook);
+	unregister_undef_hook(&kgdb_compiled_brkpt_hook);
+}
+
+/*
+ * Register our undef instruction hooks with ARM undef core.
+ * We regsiter a hook specifically looking for the KGB break inst
+ * and we handle the normal undef case within the do_undefinstr
+ * handler.
+ */
+struct kgdb_arch arch_kgdb_ops = {
+#ifndef __ARMEB__
+	.gdb_bpt_instr		= {0xfe, 0xde, 0xff, 0xe7}
+#else /* ! __ARMEB__ */
+	.gdb_bpt_instr		= {0xe7, 0xff, 0xde, 0xfe}
+#endif
+};
diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index b7b0720bc1bb..3385cb545cef 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -36,6 +36,7 @@
 #include <asm/mach/arch.h>
 #include <asm/mach/irq.h>
 #include <asm/mach/time.h>
+#include <asm/traps.h>
 
 #include "compat.h"
 #include "atags.h"
@@ -853,6 +854,10 @@ void __init setup_arch(char **cmdline_p)
 	conswitchp = &dummy_con;
 #endif
 #endif
+
+#if defined(CONFIG_KGDB)
+	early_trap_init();
+#endif
 }
 
 
diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
index 5595fdd75e82..7277aef83098 100644
--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -708,6 +708,11 @@ EXPORT_SYMBOL(abort);
 
 void __init trap_init(void)
 {
+	return;
+}
+
+void __init early_trap_init(void)
+{
 	unsigned long vectors = CONFIG_VECTORS_BASE;
 	extern char __stubs_start[], __stubs_end[];
 	extern char __vectors_start[], __vectors_end[];
diff --git a/drivers/serial/cpm_uart/cpm_uart_core.c b/drivers/serial/cpm_uart/cpm_uart_core.c
index a19dc7ef8861..d7c31efdc799 100644
--- a/drivers/serial/cpm_uart/cpm_uart_core.c
+++ b/drivers/serial/cpm_uart/cpm_uart_core.c
@@ -257,6 +257,10 @@ static void cpm_uart_int_tx(struct uart_port *port)
 	cpm_uart_tx_pump(port);
 }
 
+#ifdef CONFIG_CONSOLE_POLL
+static int serial_polled;
+#endif
+
 /*
  * Receive characters
  */
@@ -278,6 +282,12 @@ static void cpm_uart_int_rx(struct uart_port *port)
 	 */
 	bdp = pinfo->rx_cur;
 	for (;;) {
+#ifdef CONFIG_CONSOLE_POLL
+		if (unlikely(serial_polled)) {
+			serial_polled = 0;
+			return;
+		}
+#endif
 		/* get status */
 		status = in_be16(&bdp->cbd_sc);
 		/* If this one is empty, return happy */
@@ -309,7 +319,12 @@ static void cpm_uart_int_rx(struct uart_port *port)
 				goto handle_error;
 			if (uart_handle_sysrq_char(port, ch))
 				continue;
-
+#ifdef CONFIG_CONSOLE_POLL
+			if (unlikely(serial_polled)) {
+				serial_polled = 0;
+				return;
+			}
+#endif
 		      error_return:
 			tty_insert_flip_char(tty, ch, flg);
 
@@ -916,6 +931,80 @@ static void cpm_uart_config_port(struct uart_port *port, int flags)
 		cpm_uart_request_port(port);
 	}
 }
+
+#ifdef CONFIG_CONSOLE_POLL
+/* Serial polling routines for writing and reading from the uart while
+ * in an interrupt or debug context.
+ */
+
+#define GDB_BUF_SIZE	512	/* power of 2, please */
+
+static char poll_buf[GDB_BUF_SIZE];
+static char *pollp;
+static int poll_chars;
+
+static int poll_wait_key(char *obuf, struct uart_cpm_port *pinfo)
+{
+	u_char		c, *cp;
+	volatile cbd_t	*bdp;
+	int		i;
+
+	/* Get the address of the host memory buffer.
+	 */
+	bdp = pinfo->rx_cur;
+	while (bdp->cbd_sc & BD_SC_EMPTY)
+		;
+
+	/* If the buffer address is in the CPM DPRAM, don't
+	 * convert it.
+	 */
+	cp = cpm2cpu_addr(bdp->cbd_bufaddr, pinfo);
+
+	if (obuf) {
+		i = c = bdp->cbd_datlen;
+		while (i-- > 0)
+			*obuf++ = *cp++;
+	} else
+		c = *cp;
+	bdp->cbd_sc &= ~(BD_SC_BR | BD_SC_FR | BD_SC_PR | BD_SC_OV | BD_SC_ID);
+	bdp->cbd_sc |= BD_SC_EMPTY;
+
+	if (bdp->cbd_sc & BD_SC_WRAP)
+		bdp = pinfo->rx_bd_base;
+	else
+		bdp++;
+	pinfo->rx_cur = (cbd_t *)bdp;
+
+	return (int)c;
+}
+
+static int cpm_get_poll_char(struct uart_port *port)
+{
+	struct uart_cpm_port *pinfo = (struct uart_cpm_port *)port;
+
+	if (!serial_polled) {
+		serial_polled = 1;
+		poll_chars = 0;
+	}
+	if (poll_chars <= 0) {
+		poll_chars = poll_wait_key(poll_buf, pinfo);
+		pollp = poll_buf;
+	}
+	poll_chars--;
+	return (*pollp++);
+}
+
+static void cpm_put_poll_char(struct uart_port *port,
+			 unsigned char c)
+{
+	struct uart_cpm_port *pinfo = (struct uart_cpm_port *)port;
+	static char ch[2];
+
+	ch[0] = (char)c;
+	cpm_uart_early_write(pinfo->port.line, ch, 1);
+}
+#endif /* CONFIG_CONSOLE_POLL */
+
 static struct uart_ops cpm_uart_pops = {
 	.tx_empty	= cpm_uart_tx_empty,
 	.set_mctrl	= cpm_uart_set_mctrl,
@@ -933,6 +1022,10 @@ static struct uart_ops cpm_uart_pops = {
 	.request_port	= cpm_uart_request_port,
 	.config_port	= cpm_uart_config_port,
 	.verify_port	= cpm_uart_verify_port,
+#ifdef CONFIG_CONSOLE_POLL
+	.poll_get_char = cpm_get_poll_char,
+	.poll_put_char = cpm_put_poll_char,
+#endif
 };
 
 #ifdef CONFIG_PPC_CPM_NEW_BINDING
diff --git a/drivers/serial/mpsc.c b/drivers/serial/mpsc.c
index e8819c43f57d..4f967ea9192c 100644
--- a/drivers/serial/mpsc.c
+++ b/drivers/serial/mpsc.c
@@ -921,6 +921,10 @@ static int mpsc_make_ready(struct mpsc_port_info *pi)
 	return 0;
 }
 
+#ifdef CONFIG_CONSOLE_POLL
+static int serial_polled;
+#endif
+
 /*
  ******************************************************************************
  *
@@ -956,7 +960,12 @@ static int mpsc_rx_intr(struct mpsc_port_info *pi)
 	while (!((cmdstat = be32_to_cpu(rxre->cmdstat))
 				& SDMA_DESC_CMDSTAT_O)) {
 		bytes_in = be16_to_cpu(rxre->bytecnt);
-
+#ifdef CONFIG_CONSOLE_POLL
+		if (unlikely(serial_polled)) {
+			serial_polled = 0;
+			return 0;
+		}
+#endif
 		/* Following use of tty struct directly is deprecated */
 		if (unlikely(tty_buffer_request_room(tty, bytes_in)
 					< bytes_in)) {
@@ -1017,6 +1026,12 @@ static int mpsc_rx_intr(struct mpsc_port_info *pi)
 		if (uart_handle_sysrq_char(&pi->port, *bp)) {
 			bp++;
 			bytes_in--;
+#ifdef CONFIG_CONSOLE_POLL
+			if (unlikely(serial_polled)) {
+				serial_polled = 0;
+				return 0;
+			}
+#endif
 			goto next_frame;
 		}
 
@@ -1519,6 +1534,124 @@ static int mpsc_verify_port(struct uart_port *port, struct serial_struct *ser)
 
 	return rc;
 }
+#ifdef CONFIG_CONSOLE_POLL
+/* Serial polling routines for writing and reading from the uart while
+ * in an interrupt or debug context.
+ */
+
+static char poll_buf[2048];
+static int poll_ptr;
+static int poll_cnt;
+static void mpsc_put_poll_char(struct uart_port *port,
+							   unsigned char c);
+
+static int mpsc_get_poll_char(struct uart_port *port)
+{
+	struct mpsc_port_info *pi = (struct mpsc_port_info *)port;
+	struct mpsc_rx_desc *rxre;
+	u32	cmdstat, bytes_in, i;
+	u8	*bp;
+
+	if (!serial_polled)
+		serial_polled = 1;
+
+	pr_debug("mpsc_rx_intr[%d]: Handling Rx intr\n", pi->port.line);
+
+	if (poll_cnt) {
+		poll_cnt--;
+		return poll_buf[poll_ptr++];
+	}
+	poll_ptr = 0;
+	poll_cnt = 0;
+
+	while (poll_cnt == 0) {
+		rxre = (struct mpsc_rx_desc *)(pi->rxr + (pi->rxr_posn*MPSC_RXRE_SIZE));
+		dma_cache_sync(pi->port.dev, (void *)rxre, MPSC_RXRE_SIZE, DMA_FROM_DEVICE);
+#if defined(CONFIG_PPC32) && !defined(CONFIG_NOT_COHERENT_CACHE)
+		if (pi->cache_mgmt) /* GT642[46]0 Res #COMM-2 */
+			invalidate_dcache_range((ulong)rxre,
+			(ulong)rxre + MPSC_RXRE_SIZE);
+#endif
+		/*
+		 * Loop through Rx descriptors handling ones that have been completed.
+		 */
+		while (poll_cnt == 0 && !((cmdstat = be32_to_cpu(rxre->cmdstat)) & SDMA_DESC_CMDSTAT_O)){
+			bytes_in = be16_to_cpu(rxre->bytecnt);
+			bp = pi->rxb + (pi->rxr_posn * MPSC_RXBE_SIZE);
+			dma_cache_sync(pi->port.dev, (void *) bp, MPSC_RXBE_SIZE, DMA_FROM_DEVICE);
+#if defined(CONFIG_PPC32) && !defined(CONFIG_NOT_COHERENT_CACHE)
+			if (pi->cache_mgmt) /* GT642[46]0 Res #COMM-2 */
+				invalidate_dcache_range((ulong)bp,
+										(ulong)bp + MPSC_RXBE_SIZE);
+#endif
+			if ((unlikely(cmdstat & (SDMA_DESC_CMDSTAT_BR |
+									 SDMA_DESC_CMDSTAT_FR | SDMA_DESC_CMDSTAT_OR))) &&
+				!(cmdstat & pi->port.ignore_status_mask)) {
+				poll_buf[poll_cnt] = *bp;
+				poll_cnt++;
+			} else {
+				for (i=0; i<bytes_in; i++) {
+					poll_buf[poll_cnt] = *bp++;
+					poll_cnt++;
+				}
+				pi->port.icount.rx += bytes_in;
+			}
+			rxre->bytecnt = cpu_to_be16(0);
+			wmb();
+			rxre->cmdstat = cpu_to_be32(SDMA_DESC_CMDSTAT_O |
+										SDMA_DESC_CMDSTAT_EI |
+										SDMA_DESC_CMDSTAT_F |
+										SDMA_DESC_CMDSTAT_L);
+			wmb();
+			dma_cache_sync(pi->port.dev, (void *)rxre, MPSC_RXRE_SIZE, DMA_BIDIRECTIONAL);
+#if defined(CONFIG_PPC32) && !defined(CONFIG_NOT_COHERENT_CACHE)
+			if (pi->cache_mgmt) /* GT642[46]0 Res #COMM-2 */
+				flush_dcache_range((ulong)rxre,
+								   (ulong)rxre + MPSC_RXRE_SIZE);
+#endif
+
+			/* Advance to next descriptor */
+			pi->rxr_posn = (pi->rxr_posn + 1) & (MPSC_RXR_ENTRIES - 1);
+			rxre = (struct mpsc_rx_desc *)(pi->rxr +
+										   (pi->rxr_posn * MPSC_RXRE_SIZE));
+			dma_cache_sync(pi->port.dev, (void *)rxre, MPSC_RXRE_SIZE, DMA_FROM_DEVICE);
+#if defined(CONFIG_PPC32) && !defined(CONFIG_NOT_COHERENT_CACHE)
+			if (pi->cache_mgmt) /* GT642[46]0 Res #COMM-2 */
+				invalidate_dcache_range((ulong)rxre,
+										(ulong)rxre + MPSC_RXRE_SIZE);
+#endif
+		}
+
+		/* Restart rx engine, if its stopped */
+		if ((readl(pi->sdma_base + SDMA_SDCM) & SDMA_SDCM_ERD) == 0)
+			mpsc_start_rx(pi);
+	}
+	if (poll_cnt) {
+		poll_cnt--;
+		return poll_buf[poll_ptr++];
+	}
+
+	return 0;
+}
+
+
+static void mpsc_put_poll_char(struct uart_port *port,
+			 unsigned char c)
+{
+	struct mpsc_port_info *pi = (struct mpsc_port_info *)port;
+	u32 data;
+
+	data = readl(pi->mpsc_base + MPSC_MPCR);
+	writeb(c, pi->mpsc_base + MPSC_CHR_1);
+	mb();
+	data = readl(pi->mpsc_base + MPSC_CHR_2);
+	data |= MPSC_CHR_2_TTCS;
+	writel(data, pi->mpsc_base + MPSC_CHR_2);
+	mb();
+
+	while (readl(pi->mpsc_base + MPSC_CHR_2) & MPSC_CHR_2_TTCS) ;
+}
+#endif
 
 static struct uart_ops mpsc_pops = {
 	.tx_empty	= mpsc_tx_empty,
@@ -1537,6 +1670,10 @@ static struct uart_ops mpsc_pops = {
 	.request_port	= mpsc_request_port,
 	.config_port	= mpsc_config_port,
 	.verify_port	= mpsc_verify_port,
+#ifdef CONFIG_CONSOLE_POLL
+	.poll_get_char = mpsc_get_poll_char,
+	.poll_put_char = mpsc_put_poll_char,
+#endif
 };
 
 /*
diff --git a/include/asm-arm/kgdb.h b/include/asm-arm/kgdb.h
new file mode 100644
index 000000000000..67af4b841984
--- /dev/null
+++ b/include/asm-arm/kgdb.h
@@ -0,0 +1,104 @@
+/*
+ * ARM KGDB support
+ *
+ * Author: Deepak Saxena <dsaxena@mvista.com>
+ *
+ * Copyright (C) 2002 MontaVista Software Inc.
+ *
+ */
+
+#ifndef __ARM_KGDB_H__
+#define __ARM_KGDB_H__
+
+#include <linux/ptrace.h>
+
+/*
+ * GDB assumes that we're a user process being debugged, so
+ * it will send us an SWI command to write into memory as the
+ * debug trap. When an SWI occurs, the next instruction addr is
+ * placed into R14_svc before jumping to the vector trap.
+ * This doesn't work for kernel debugging as we are already in SVC
+ * we would loose the kernel's LR, which is a bad thing. This
+ * is  bad thing.
+ *
+ * By doing this as an undefined instruction trap, we force a mode
+ * switch from SVC to UND mode, allowing us to save full kernel state.
+ *
+ * We also define a KGDB_COMPILED_BREAK which can be used to compile
+ * in breakpoints. This is important for things like sysrq-G and for
+ * the initial breakpoint from trap_init().
+ *
+ * Note to ARM HW designers: Add real trap support like SH && PPC to
+ * make our lives much much simpler. :)
+ */
+#define BREAK_INSTR_SIZE	4
+#define GDB_BREAKINST		0xef9f0001
+#define KGDB_BREAKINST		0xe7ffdefe
+#define KGDB_COMPILED_BREAK	0xe7ffdeff
+#define CACHE_FLUSH_IS_SAFE	1
+
+#ifndef	__ASSEMBLY__
+
+static inline void arch_kgdb_breakpoint(void)
+{
+	asm(".word 0xe7ffdeff");
+}
+
+extern void kgdb_handle_bus_error(void);
+extern int kgdb_fault_expected;
+
+#endif /* !__ASSEMBLY__ */
+
+/*
+ * From Kevin Hilman:
+ *
+ * gdb is expecting the following registers layout.
+ *
+ * r0-r15: 1 long word each
+ * f0-f7:  unused, 3 long words each !!
+ * fps:    unused, 1 long word
+ * cpsr:   1 long word
+ *
+ * Even though f0-f7 and fps are not used, they need to be
+ * present in the registers sent for correct processing in
+ * the host-side gdb.
+ *
+ * In particular, it is crucial that CPSR is in the right place,
+ * otherwise gdb will not be able to correctly interpret stepping over
+ * conditional branches.
+ */
+#define _GP_REGS		16
+#define _FP_REGS		8
+#define _EXTRA_REGS		2
+#define GDB_MAX_REGS		(_GP_REGS + (_FP_REGS * 3) + _EXTRA_REGS)
+
+#define KGDB_MAX_NO_CPUS	1
+#define BUFMAX			400
+#define NUMREGBYTES		(GDB_MAX_REGS << 2)
+#define NUMCRITREGBYTES		(32 << 2)
+
+#define _R0			0
+#define _R1			1
+#define _R2			2
+#define _R3			3
+#define _R4			4
+#define _R5			5
+#define _R6			6
+#define _R7			7
+#define _R8			8
+#define _R9			9
+#define _R10			10
+#define _FP			11
+#define _IP			12
+#define _SPT			13
+#define _LR			14
+#define _PC			15
+#define _CPSR			(GDB_MAX_REGS - 1)
+
+/*
+ * So that we can denote the end of a frame for tracing,
+ * in the simple case:
+ */
+#define CFI_END_FRAME(func)	__CFI_END_FRAME(_PC, _SPT, func)
+
+#endif /* __ASM_KGDB_H__ */
diff --git a/include/asm-arm/traps.h b/include/asm-arm/traps.h
index f1541afcf85c..aa399aec568e 100644
--- a/include/asm-arm/traps.h
+++ b/include/asm-arm/traps.h
@@ -24,4 +24,6 @@ static inline int in_exception_text(unsigned long ptr)
 	       ptr < (unsigned long)&__exception_text_end;
 }
 
+extern void __init early_trap_init(void);
+
 #endif