Merge branch 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm

* 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm: (422 commits)
  [ARM] 5435/1: fix compile warning in sanity_check_meminfo()
  [ARM] 5434/1: ARM: OMAP: Fix mailbox compile for 24xx
  [ARM] pxa: fix the bad assumption that PCMCIA sockets always start with 0
  [ARM] pxa: fix Colibri PXA300 and PXA320 LCD backlight pins
  imxfb: Fix TFT mode
  i.MX21/27: remove ifdef CONFIG_FB_IMX
  imxfb: add clock support
  mxc: add arch_reset() function
  clkdev: add possibility to get a clock based on the device name
  i.MX1: remove fb support from mach-imx
  [ARM] pxa: build arch/arm/plat-pxa/mfp.c only when PXA3xx or ARCH_MMP defined
  Gemini: Add support for Teltonika RUT100
  Gemini: gpiolib based GPIO support v2
  MAINTAINERS: add myself as Gemini architecture maintainer
  ARM: Add Gemini architecture v3
  [ARM] OMAP: Fix compile for omap2_init_common_hw()
  MAINTAINERS: Add myself as Faraday ARM core variant maintainer
  ARM: Add support for FA526 v2
  [ARM] acorn,ebsa110,footbridge,integrator,sa1100: Convert asm/io.h to linux/io.h
  [ARM] collie: fix two minor formatting nits
  ...

17 files changed, 863 insertions, 159 deletions

diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile
index 4305345987d..11a5197a221 100644
--- a/arch/arm/kernel/Makefile
+++ b/arch/arm/kernel/Makefile
@@ -29,12 +29,14 @@ 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_ARM_UNWIND)	+= unwind.o
 
 obj-$(CONFIG_CRUNCH)		+= crunch.o crunch-bits.o
 AFLAGS_crunch-bits.o		:= -Wa,-mcpu=ep9312
 
 obj-$(CONFIG_CPU_XSCALE)	+= xscale-cp0.o
 obj-$(CONFIG_CPU_XSC3)		+= xscale-cp0.o
+obj-$(CONFIG_CPU_MOHAWK)	+= xscale-cp0.o
 obj-$(CONFIG_IWMMXT)		+= iwmmxt.o
 AFLAGS_iwmmxt.o			:= -Wa,-mcpu=iwmmxt
 
diff --git a/arch/arm/kernel/debug.S b/arch/arm/kernel/debug.S
index f53c5829054..b121b6053cc 100644
--- a/arch/arm/kernel/debug.S
+++ b/arch/arm/kernel/debug.S
@@ -49,6 +49,33 @@
 1002:
 		.endm
 
+#elif defined(CONFIG_CPU_XSCALE)
+
+		.macro	addruart, rx
+		.endm
+
+		.macro	senduart, rd, rx
+		mcr	p14, 0, \rd, c8, c0, 0
+		.endm
+
+		.macro	busyuart, rd, rx
+1001:
+		mrc	p14, 0, \rx, c14, c0, 0
+		tst	\rx, #0x10000000
+		beq	1001b
+		.endm
+
+		.macro	waituart, rd, rx
+		mov	\rd, #0x10000000
+1001:
+		subs	\rd, \rd, #1
+		bmi	1002f
+		mrc	p14, 0, \rx, c14, c0, 0
+		tst	\rx, #0x10000000
+		bne	1001b
+1002:
+		.endm
+
 #else
 
 		.macro	addruart, rx
diff --git a/arch/arm/kernel/dma-isa.c b/arch/arm/kernel/dma-isa.c
index 4a3a50495c6..0e88e46fc73 100644
--- a/arch/arm/kernel/dma-isa.c
+++ b/arch/arm/kernel/dma-isa.c
@@ -24,11 +24,6 @@
 #include <asm/dma.h>
 #include <asm/mach/dma.h>
 
-#define ISA_DMA_MODE_READ	0x44
-#define ISA_DMA_MODE_WRITE	0x48
-#define ISA_DMA_MODE_CASCADE	0xc0
-#define ISA_DMA_AUTOINIT	0x10
-
 #define ISA_DMA_MASK		0
 #define ISA_DMA_MODE		1
 #define ISA_DMA_CLRFF		2
@@ -49,38 +44,35 @@ static unsigned int isa_dma_port[8][7] = {
 	{  0xd4,  0xd6,  0xd8,  0x48a,  0x08a,  0xcc, 0xce }
 };
 
-static int isa_get_dma_residue(dmach_t channel, dma_t *dma)
+static int isa_get_dma_residue(unsigned int chan, dma_t *dma)
 {
-	unsigned int io_port = isa_dma_port[channel][ISA_DMA_COUNT];
+	unsigned int io_port = isa_dma_port[chan][ISA_DMA_COUNT];
 	int count;
 
 	count = 1 + inb(io_port);
 	count |= inb(io_port) << 8;
 
-	return channel < 4 ? count : (count << 1);
+	return chan < 4 ? count : (count << 1);
 }
 
-static void isa_enable_dma(dmach_t channel, dma_t *dma)
+static void isa_enable_dma(unsigned int chan, dma_t *dma)
 {
 	if (dma->invalid) {
 		unsigned long address, length;
 		unsigned int mode;
 		enum dma_data_direction direction;
 
-		mode = channel & 3;
+		mode = (chan & 3) | dma->dma_mode;
 		switch (dma->dma_mode & DMA_MODE_MASK) {
 		case DMA_MODE_READ:
-			mode |= ISA_DMA_MODE_READ;
 			direction = DMA_FROM_DEVICE;
 			break;
 
 		case DMA_MODE_WRITE:
-			mode |= ISA_DMA_MODE_WRITE;
 			direction = DMA_TO_DEVICE;
 			break;
 
 		case DMA_MODE_CASCADE:
-			mode |= ISA_DMA_MODE_CASCADE;
 			direction = DMA_BIDIRECTIONAL;
 			break;
 
@@ -105,34 +97,31 @@ static void isa_enable_dma(dmach_t channel, dma_t *dma)
 		address = dma->buf.dma_address;
 		length  = dma->buf.length - 1;
 
-		outb(address >> 16, isa_dma_port[channel][ISA_DMA_PGLO]);
-		outb(address >> 24, isa_dma_port[channel][ISA_DMA_PGHI]);
+		outb(address >> 16, isa_dma_port[chan][ISA_DMA_PGLO]);
+		outb(address >> 24, isa_dma_port[chan][ISA_DMA_PGHI]);
 
-		if (channel >= 4) {
+		if (chan >= 4) {
 			address >>= 1;
 			length >>= 1;
 		}
 
-		outb(0, isa_dma_port[channel][ISA_DMA_CLRFF]);
-
-		outb(address, isa_dma_port[channel][ISA_DMA_ADDR]);
-		outb(address >> 8, isa_dma_port[channel][ISA_DMA_ADDR]);
+		outb(0, isa_dma_port[chan][ISA_DMA_CLRFF]);
 
-		outb(length, isa_dma_port[channel][ISA_DMA_COUNT]);
-		outb(length >> 8, isa_dma_port[channel][ISA_DMA_COUNT]);
+		outb(address, isa_dma_port[chan][ISA_DMA_ADDR]);
+		outb(address >> 8, isa_dma_port[chan][ISA_DMA_ADDR]);
 
-		if (dma->dma_mode & DMA_AUTOINIT)
-			mode |= ISA_DMA_AUTOINIT;
+		outb(length, isa_dma_port[chan][ISA_DMA_COUNT]);
+		outb(length >> 8, isa_dma_port[chan][ISA_DMA_COUNT]);
 
-		outb(mode, isa_dma_port[channel][ISA_DMA_MODE]);
+		outb(mode, isa_dma_port[chan][ISA_DMA_MODE]);
 		dma->invalid = 0;
 	}
-	outb(channel & 3, isa_dma_port[channel][ISA_DMA_MASK]);
+	outb(chan & 3, isa_dma_port[chan][ISA_DMA_MASK]);
 }
 
-static void isa_disable_dma(dmach_t channel, dma_t *dma)
+static void isa_disable_dma(unsigned int chan, dma_t *dma)
 {
-	outb(channel | 4, isa_dma_port[channel][ISA_DMA_MASK]);
+	outb(chan | 4, isa_dma_port[chan][ISA_DMA_MASK]);
 }
 
 static struct dma_ops isa_dma_ops = {
@@ -160,7 +149,12 @@ static struct resource dma_resources[] = { {
 	.end	= 0x048f
 } };
 
-void __init isa_init_dma(dma_t *dma)
+static dma_t isa_dma[8];
+
+/*
+ * ISA DMA always starts at channel 0
+ */
+void __init isa_init_dma(void)
 {
 	/*
 	 * Try to autodetect presence of an ISA DMA controller.
@@ -178,11 +172,11 @@ void __init isa_init_dma(dma_t *dma)
 	outb(0xaa, 0x00);
 
 	if (inb(0) == 0x55 && inb(0) == 0xaa) {
-		int channel, i;
+		unsigned int chan, i;
 
-		for (channel = 0; channel < 8; channel++) {
-			dma[channel].d_ops = &isa_dma_ops;
-			isa_disable_dma(channel, NULL);
+		for (chan = 0; chan < 8; chan++) {
+			isa_dma[chan].d_ops = &isa_dma_ops;
+			isa_disable_dma(chan, NULL);
 		}
 
 		outb(0x40, 0x0b);
@@ -217,5 +211,12 @@ void __init isa_init_dma(dma_t *dma)
 
 		for (i = 0; i < ARRAY_SIZE(dma_resources); i++)
 			request_resource(&ioport_resource, dma_resources + i);
+
+		for (chan = 0; chan < 8; chan++) {
+			int ret = isa_dma_add(chan, &isa_dma[chan]);
+			if (ret)
+				printk(KERN_ERR "ISADMA%u: unable to register: %d\n",
+					chan, ret);
+		}
 	}
 }
diff --git a/arch/arm/kernel/dma.c b/arch/arm/kernel/dma.c
index d006085ed7e..7d5b9fb01e7 100644
--- a/arch/arm/kernel/dma.c
+++ b/arch/arm/kernel/dma.c
@@ -15,6 +15,7 @@
 #include <linux/init.h>
 #include <linux/spinlock.h>
 #include <linux/errno.h>
+#include <linux/scatterlist.h>
 
 #include <asm/dma.h>
 
@@ -23,19 +24,40 @@
 DEFINE_SPINLOCK(dma_spin_lock);
 EXPORT_SYMBOL(dma_spin_lock);
 
-static dma_t dma_chan[MAX_DMA_CHANNELS];
+static dma_t *dma_chan[MAX_DMA_CHANNELS];
+
+static inline dma_t *dma_channel(unsigned int chan)
+{
+	if (chan >= MAX_DMA_CHANNELS)
+		return NULL;
+
+	return dma_chan[chan];
+}
+
+int __init isa_dma_add(unsigned int chan, dma_t *dma)
+{
+	if (!dma->d_ops)
+		return -EINVAL;
+
+	sg_init_table(&dma->buf, 1);
+
+	if (dma_chan[chan])
+		return -EBUSY;
+	dma_chan[chan] = dma;
+	return 0;
+}
 
 /*
  * Request DMA channel
  *
  * On certain platforms, we have to allocate an interrupt as well...
  */
-int request_dma(dmach_t channel, const char *device_id)
+int request_dma(unsigned int chan, const char *device_id)
 {
-	dma_t *dma = dma_chan + channel;
+	dma_t *dma = dma_channel(chan);
 	int ret;
 
-	if (channel >= MAX_DMA_CHANNELS || !dma->d_ops)
+	if (!dma)
 		goto bad_dma;
 
 	if (xchg(&dma->lock, 1) != 0)
@@ -47,7 +69,7 @@ int request_dma(dmach_t channel, const char *device_id)
 
 	ret = 0;
 	if (dma->d_ops->request)
-		ret = dma->d_ops->request(channel, dma);
+		ret = dma->d_ops->request(chan, dma);
 
 	if (ret)
 		xchg(&dma->lock, 0);
@@ -55,7 +77,7 @@ int request_dma(dmach_t channel, const char *device_id)
 	return ret;
 
 bad_dma:
-	printk(KERN_ERR "dma: trying to allocate DMA%d\n", channel);
+	printk(KERN_ERR "dma: trying to allocate DMA%d\n", chan);
 	return -EINVAL;
 
 busy:
@@ -68,42 +90,42 @@ EXPORT_SYMBOL(request_dma);
  *
  * On certain platforms, we have to free interrupt as well...
  */
-void free_dma(dmach_t channel)
+void free_dma(unsigned int chan)
 {
-	dma_t *dma = dma_chan + channel;
+	dma_t *dma = dma_channel(chan);
 
-	if (channel >= MAX_DMA_CHANNELS || !dma->d_ops)
+	if (!dma)
 		goto bad_dma;
 
 	if (dma->active) {
-		printk(KERN_ERR "dma%d: freeing active DMA\n", channel);
-		dma->d_ops->disable(channel, dma);
+		printk(KERN_ERR "dma%d: freeing active DMA\n", chan);
+		dma->d_ops->disable(chan, dma);
 		dma->active = 0;
 	}
 
 	if (xchg(&dma->lock, 0) != 0) {
 		if (dma->d_ops->free)
-			dma->d_ops->free(channel, dma);
+			dma->d_ops->free(chan, dma);
 		return;
 	}
 
-	printk(KERN_ERR "dma%d: trying to free free DMA\n", channel);
+	printk(KERN_ERR "dma%d: trying to free free DMA\n", chan);
 	return;
 
 bad_dma:
-	printk(KERN_ERR "dma: trying to free DMA%d\n", channel);
+	printk(KERN_ERR "dma: trying to free DMA%d\n", chan);
 }
 EXPORT_SYMBOL(free_dma);
 
 /* Set DMA Scatter-Gather list
  */
-void set_dma_sg (dmach_t channel, struct scatterlist *sg, int nr_sg)
+void set_dma_sg (unsigned int chan, struct scatterlist *sg, int nr_sg)
 {
-	dma_t *dma = dma_chan + channel;
+	dma_t *dma = dma_channel(chan);
 
 	if (dma->active)
 		printk(KERN_ERR "dma%d: altering DMA SG while "
-		       "DMA active\n", channel);
+		       "DMA active\n", chan);
 
 	dma->sg = sg;
 	dma->sgcount = nr_sg;
@@ -115,13 +137,13 @@ EXPORT_SYMBOL(set_dma_sg);
  *
  * Copy address to the structure, and set the invalid bit
  */
-void __set_dma_addr (dmach_t channel, void *addr)
+void __set_dma_addr (unsigned int chan, void *addr)
 {
-	dma_t *dma = dma_chan + channel;
+	dma_t *dma = dma_channel(chan);
 
 	if (dma->active)
 		printk(KERN_ERR "dma%d: altering DMA address while "
-		       "DMA active\n", channel);
+		       "DMA active\n", chan);
 
 	dma->sg = NULL;
 	dma->addr = addr;
@@ -133,13 +155,13 @@ EXPORT_SYMBOL(__set_dma_addr);
  *
  * Copy address to the structure, and set the invalid bit
  */
-void set_dma_count (dmach_t channel, unsigned long count)
+void set_dma_count (unsigned int chan, unsigned long count)
 {
-	dma_t *dma = dma_chan + channel;
+	dma_t *dma = dma_channel(chan);
 
 	if (dma->active)
 		printk(KERN_ERR "dma%d: altering DMA count while "
-		       "DMA active\n", channel);
+		       "DMA active\n", chan);
 
 	dma->sg = NULL;
 	dma->count = count;
@@ -149,13 +171,13 @@ EXPORT_SYMBOL(set_dma_count);
 
 /* Set DMA direction mode
  */
-void set_dma_mode (dmach_t channel, dmamode_t mode)
+void set_dma_mode (unsigned int chan, unsigned int mode)
 {
-	dma_t *dma = dma_chan + channel;
+	dma_t *dma = dma_channel(chan);
 
 	if (dma->active)
 		printk(KERN_ERR "dma%d: altering DMA mode while "
-		       "DMA active\n", channel);
+		       "DMA active\n", chan);
 
 	dma->dma_mode = mode;
 	dma->invalid = 1;
@@ -164,42 +186,42 @@ EXPORT_SYMBOL(set_dma_mode);
 
 /* Enable DMA channel
  */
-void enable_dma (dmach_t channel)
+void enable_dma (unsigned int chan)
 {
-	dma_t *dma = dma_chan + channel;
+	dma_t *dma = dma_channel(chan);
 
 	if (!dma->lock)
 		goto free_dma;
 
 	if (dma->active == 0) {
 		dma->active = 1;
-		dma->d_ops->enable(channel, dma);
+		dma->d_ops->enable(chan, dma);
 	}
 	return;
 
 free_dma:
-	printk(KERN_ERR "dma%d: trying to enable free DMA\n", channel);
+	printk(KERN_ERR "dma%d: trying to enable free DMA\n", chan);
 	BUG();
 }
 EXPORT_SYMBOL(enable_dma);
 
 /* Disable DMA channel
  */
-void disable_dma (dmach_t channel)
+void disable_dma (unsigned int chan)
 {
-	dma_t *dma = dma_chan + channel;
+	dma_t *dma = dma_channel(chan);
 
 	if (!dma->lock)
 		goto free_dma;
 
 	if (dma->active == 1) {
 		dma->active = 0;
-		dma->d_ops->disable(channel, dma);
+		dma->d_ops->disable(chan, dma);
 	}
 	return;
 
 free_dma:
-	printk(KERN_ERR "dma%d: trying to disable free DMA\n", channel);
+	printk(KERN_ERR "dma%d: trying to disable free DMA\n", chan);
 	BUG();
 }
 EXPORT_SYMBOL(disable_dma);
@@ -207,45 +229,38 @@ EXPORT_SYMBOL(disable_dma);
 /*
  * Is the specified DMA channel active?
  */
-int dma_channel_active(dmach_t channel)
+int dma_channel_active(unsigned int chan)
 {
-	return dma_chan[channel].active;
+	dma_t *dma = dma_channel(chan);
+	return dma->active;
 }
 EXPORT_SYMBOL(dma_channel_active);
 
-void set_dma_page(dmach_t channel, char pagenr)
+void set_dma_page(unsigned int chan, char pagenr)
 {
-	printk(KERN_ERR "dma%d: trying to set_dma_page\n", channel);
+	printk(KERN_ERR "dma%d: trying to set_dma_page\n", chan);
 }
 EXPORT_SYMBOL(set_dma_page);
 
-void set_dma_speed(dmach_t channel, int cycle_ns)
+void set_dma_speed(unsigned int chan, int cycle_ns)
 {
-	dma_t *dma = dma_chan + channel;
+	dma_t *dma = dma_channel(chan);
 	int ret = 0;
 
 	if (dma->d_ops->setspeed)
-		ret = dma->d_ops->setspeed(channel, dma, cycle_ns);
+		ret = dma->d_ops->setspeed(chan, dma, cycle_ns);
 	dma->speed = ret;
 }
 EXPORT_SYMBOL(set_dma_speed);
 
-int get_dma_residue(dmach_t channel)
+int get_dma_residue(unsigned int chan)
 {
-	dma_t *dma = dma_chan + channel;
+	dma_t *dma = dma_channel(chan);
 	int ret = 0;
 
 	if (dma->d_ops->residue)
-		ret = dma->d_ops->residue(channel, dma);
+		ret = dma->d_ops->residue(chan, dma);
 
 	return ret;
 }
 EXPORT_SYMBOL(get_dma_residue);
-
-static int __init init_dma(void)
-{
-	arch_dma_init(dma_chan);
-	return 0;
-}
-
-core_initcall(init_dma);
diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S
index 85040cfeb5e..d662a2f1fd8 100644
--- a/arch/arm/kernel/entry-armv.S
+++ b/arch/arm/kernel/entry-armv.S
@@ -20,6 +20,7 @@
 #include <asm/vfpmacros.h>
 #include <mach/entry-macro.S>
 #include <asm/thread_notify.h>
+#include <asm/unwind.h>
 
 #include "entry-header.S"
 
@@ -123,6 +124,8 @@ ENDPROC(__und_invalid)
 #endif
 
 	.macro	svc_entry, stack_hole=0
+ UNWIND(.fnstart		)
+ UNWIND(.save {r0 - pc}		)
 	sub	sp, sp, #(S_FRAME_SIZE + \stack_hole)
  SPFIX(	tst	sp, #4		)
  SPFIX(	bicne	sp, sp, #4	)
@@ -196,6 +199,7 @@ __dabt_svc:
 	ldr	r0, [sp, #S_PSR]
 	msr	spsr_cxsf, r0
 	ldmia	sp, {r0 - pc}^			@ load r0 - pc, cpsr
+ UNWIND(.fnend		)
 ENDPROC(__dabt_svc)
 
 	.align	5
@@ -228,6 +232,7 @@ __irq_svc:
 	bleq	trace_hardirqs_on
 #endif
 	ldmia	sp, {r0 - pc}^			@ load r0 - pc, cpsr
+ UNWIND(.fnend		)
 ENDPROC(__irq_svc)
 
 	.ltorg
@@ -278,6 +283,7 @@ __und_svc:
 	ldr	lr, [sp, #S_PSR]		@ Get SVC cpsr
 	msr	spsr_cxsf, lr
 	ldmia	sp, {r0 - pc}^			@ Restore SVC registers
+ UNWIND(.fnend		)
 ENDPROC(__und_svc)
 
 	.align	5
@@ -320,6 +326,7 @@ __pabt_svc:
 	ldr	r0, [sp, #S_PSR]
 	msr	spsr_cxsf, r0
 	ldmia	sp, {r0 - pc}^			@ load r0 - pc, cpsr
+ UNWIND(.fnend		)
 ENDPROC(__pabt_svc)
 
 	.align	5
@@ -343,6 +350,8 @@ ENDPROC(__pabt_svc)
 #endif
 
 	.macro	usr_entry
+ UNWIND(.fnstart	)
+ UNWIND(.cantunwind	)	@ don't unwind the user space
 	sub	sp, sp, #S_FRAME_SIZE
 	stmib	sp, {r1 - r12}
 
@@ -420,6 +429,7 @@ __dabt_usr:
 	mov	r2, sp
 	adr	lr, ret_from_exception
 	b	do_DataAbort
+ UNWIND(.fnend		)
 ENDPROC(__dabt_usr)
 
 	.align	5
@@ -450,6 +460,7 @@ __irq_usr:
 
 	mov	why, #0
 	b	ret_to_user
+ UNWIND(.fnend		)
 ENDPROC(__irq_usr)
 
 	.ltorg
@@ -484,6 +495,7 @@ __und_usr:
 #else
 	b	__und_usr_unknown
 #endif
+ UNWIND(.fnend		)
 ENDPROC(__und_usr)
 
 	@
@@ -671,14 +683,18 @@ __pabt_usr:
 	enable_irq				@ Enable interrupts
 	mov	r1, sp				@ regs
 	bl	do_PrefetchAbort		@ call abort handler
+ UNWIND(.fnend		)
 	/* fall through */
 /*
  * This is the return code to user mode for abort handlers
  */
 ENTRY(ret_from_exception)
+ UNWIND(.fnstart	)
+ UNWIND(.cantunwind	)
 	get_thread_info tsk
 	mov	why, #0
 	b	ret_to_user
+ UNWIND(.fnend		)
 ENDPROC(__pabt_usr)
 ENDPROC(ret_from_exception)
 
@@ -688,6 +704,8 @@ ENDPROC(ret_from_exception)
  * previous and next are guaranteed not to be the same.
  */
 ENTRY(__switch_to)
+ UNWIND(.fnstart	)
+ UNWIND(.cantunwind	)
 	add	ip, r1, #TI_CPU_SAVE
 	ldr	r3, [r2, #TI_TP_VALUE]
 	stmia	ip!, {r4 - sl, fp, sp, lr}	@ Store most regs on stack
@@ -717,6 +735,7 @@ ENTRY(__switch_to)
 	bl	atomic_notifier_call_chain
 	mov	r0, r5
 	ldmia	r4, {r4 - sl, fp, sp, pc}	@ Load all regs saved previously
+ UNWIND(.fnend		)
 ENDPROC(__switch_to)
 
 	__INIT
diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S
index 159d0416f27..b55cb033180 100644
--- a/arch/arm/kernel/entry-common.S
+++ b/arch/arm/kernel/entry-common.S
@@ -11,6 +11,7 @@
 #include <asm/unistd.h>
 #include <asm/ftrace.h>
 #include <mach/entry-macro.S>
+#include <asm/unwind.h>
 
 #include "entry-header.S"
 
@@ -22,6 +23,8 @@
  * stack.
  */
 ret_fast_syscall:
+ UNWIND(.fnstart	)
+ UNWIND(.cantunwind	)
 	disable_irq				@ disable interrupts
 	ldr	r1, [tsk, #TI_FLAGS]
 	tst	r1, #_TIF_WORK_MASK
@@ -38,6 +41,7 @@ ret_fast_syscall:
 	mov	r0, r0
 	add	sp, sp, #S_FRAME_SIZE - S_PC
 	movs	pc, lr				@ return & move spsr_svc into cpsr
+ UNWIND(.fnend		)
 
 /*
  * Ok, we need to do extra processing, enter the slow path.
diff --git a/arch/arm/kernel/module.c b/arch/arm/kernel/module.c
index dab48f27263..d1731e39b49 100644
--- a/arch/arm/kernel/module.c
+++ b/arch/arm/kernel/module.c
@@ -22,6 +22,7 @@
 
 #include <asm/pgtable.h>
 #include <asm/sections.h>
+#include <asm/unwind.h>
 
 #ifdef CONFIG_XIP_KERNEL
 /*
@@ -66,6 +67,24 @@ int module_frob_arch_sections(Elf_Ehdr *hdr,
 			      char *secstrings,
 			      struct module *mod)
 {
+#ifdef CONFIG_ARM_UNWIND
+	Elf_Shdr *s, *sechdrs_end = sechdrs + hdr->e_shnum;
+
+	for (s = sechdrs; s < sechdrs_end; s++) {
+		if (strcmp(".ARM.exidx.init.text", secstrings + s->sh_name) == 0)
+			mod->arch.unw_sec_init = s;
+		else if (strcmp(".ARM.exidx.devinit.text", secstrings + s->sh_name) == 0)
+			mod->arch.unw_sec_devinit = s;
+		else if (strcmp(".ARM.exidx", secstrings + s->sh_name) == 0)
+			mod->arch.unw_sec_core = s;
+		else if (strcmp(".init.text", secstrings + s->sh_name) == 0)
+			mod->arch.sec_init_text = s;
+		else if (strcmp(".devinit.text", secstrings + s->sh_name) == 0)
+			mod->arch.sec_devinit_text = s;
+		else if (strcmp(".text", secstrings + s->sh_name) == 0)
+			mod->arch.sec_core_text = s;
+	}
+#endif
 	return 0;
 }
 
@@ -104,6 +123,10 @@ apply_relocate(Elf32_Shdr *sechdrs, const char *strtab, unsigned int symindex,
 		loc = dstsec->sh_addr + rel->r_offset;
 
 		switch (ELF32_R_TYPE(rel->r_info)) {
+		case R_ARM_NONE:
+			/* ignore */
+			break;
+
 		case R_ARM_ABS32:
 			*(u32 *)loc += sym->st_value;
 			break;
@@ -132,6 +155,20 @@ apply_relocate(Elf32_Shdr *sechdrs, const char *strtab, unsigned int symindex,
 			*(u32 *)loc |= offset & 0x00ffffff;
 			break;
 
+	       case R_ARM_V4BX:
+		       /* Preserve Rm and the condition code. Alter
+			* other bits to re-code instruction as
+			* MOV PC,Rm.
+			*/
+		       *(u32 *)loc &= 0xf000000f;
+		       *(u32 *)loc |= 0x01a0f000;
+		       break;
+
+		case R_ARM_PREL31:
+			offset = *(u32 *)loc + sym->st_value - loc;
+			*(u32 *)loc = offset & 0x7fffffff;
+			break;
+
 		default:
 			printk(KERN_ERR "%s: unknown relocation: %u\n",
 			       module->name, ELF32_R_TYPE(rel->r_info));
@@ -150,14 +187,50 @@ apply_relocate_add(Elf32_Shdr *sechdrs, const char *strtab,
 	return -ENOEXEC;
 }
 
+#ifdef CONFIG_ARM_UNWIND
+static void register_unwind_tables(struct module *mod)
+{
+	if (mod->arch.unw_sec_init && mod->arch.sec_init_text)
+		mod->arch.unwind_init =
+			unwind_table_add(mod->arch.unw_sec_init->sh_addr,
+					 mod->arch.unw_sec_init->sh_size,
+					 mod->arch.sec_init_text->sh_addr,
+					 mod->arch.sec_init_text->sh_size);
+	if (mod->arch.unw_sec_devinit && mod->arch.sec_devinit_text)
+		mod->arch.unwind_devinit =
+			unwind_table_add(mod->arch.unw_sec_devinit->sh_addr,
+					 mod->arch.unw_sec_devinit->sh_size,
+					 mod->arch.sec_devinit_text->sh_addr,
+					 mod->arch.sec_devinit_text->sh_size);
+	if (mod->arch.unw_sec_core && mod->arch.sec_core_text)
+		mod->arch.unwind_core =
+			unwind_table_add(mod->arch.unw_sec_core->sh_addr,
+					 mod->arch.unw_sec_core->sh_size,
+					 mod->arch.sec_core_text->sh_addr,
+					 mod->arch.sec_core_text->sh_size);
+}
+
+static void unregister_unwind_tables(struct module *mod)
+{
+	unwind_table_del(mod->arch.unwind_init);
+	unwind_table_del(mod->arch.unwind_devinit);
+	unwind_table_del(mod->arch.unwind_core);
+}
+#else
+static inline void register_unwind_tables(struct module *mod) { }
+static inline void unregister_unwind_tables(struct module *mod) { }
+#endif
+
 int
 module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs,
 		struct module *module)
 {
+	register_unwind_tables(module);
 	return 0;
 }
 
 void
 module_arch_cleanup(struct module *mod)
 {
+	unregister_unwind_tables(mod);
 }
diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index d3ea6fa8952..2de14e2afdc 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -34,6 +34,7 @@
 #include <asm/processor.h>
 #include <asm/system.h>
 #include <asm/thread_notify.h>
+#include <asm/stacktrace.h>
 #include <asm/mach/time.h>
 
 static const char *processor_modes[] = {
@@ -82,7 +83,7 @@ static int __init hlt_setup(char *__unused)
 __setup("nohlt", nohlt_setup);
 __setup("hlt", hlt_setup);
 
-void arm_machine_restart(char mode)
+void arm_machine_restart(char mode, const char *cmd)
 {
 	/*
 	 * Clean and disable cache, and turn off interrupts
@@ -99,7 +100,7 @@ void arm_machine_restart(char mode)
 	/*
 	 * Now call the architecture specific reboot code.
 	 */
-	arch_reset(mode);
+	arch_reset(mode, cmd);
 
 	/*
 	 * Whoops - the architecture was unable to reboot.
@@ -119,7 +120,7 @@ EXPORT_SYMBOL(pm_idle);
 void (*pm_power_off)(void);
 EXPORT_SYMBOL(pm_power_off);
 
-void (*arm_pm_restart)(char str) = arm_machine_restart;
+void (*arm_pm_restart)(char str, const char *cmd) = arm_machine_restart;
 EXPORT_SYMBOL_GPL(arm_pm_restart);
 
 
@@ -194,9 +195,9 @@ void machine_power_off(void)
 		pm_power_off();
 }
 
-void machine_restart(char * __unused)
+void machine_restart(char *cmd)
 {
-	arm_pm_restart(reboot_mode);
+	arm_pm_restart(reboot_mode, cmd);
 }
 
 void __show_regs(struct pt_regs *regs)
@@ -372,23 +373,21 @@ EXPORT_SYMBOL(kernel_thread);
 
 unsigned long get_wchan(struct task_struct *p)
 {
-	unsigned long fp, lr;
-	unsigned long stack_start, stack_end;
+	struct stackframe frame;
 	int count = 0;
 	if (!p || p == current || p->state == TASK_RUNNING)
 		return 0;
 
-	stack_start = (unsigned long)end_of_stack(p);
-	stack_end = (unsigned long)task_stack_page(p) + THREAD_SIZE;
-
-	fp = thread_saved_fp(p);
+	frame.fp = thread_saved_fp(p);
+	frame.sp = thread_saved_sp(p);
+	frame.lr = 0;			/* recovered from the stack */
+	frame.pc = thread_saved_pc(p);
 	do {
-		if (fp < stack_start || fp > stack_end)
+		int ret = unwind_frame(&frame);
+		if (ret < 0)
 			return 0;
-		lr = ((unsigned long *)fp)[-1];
-		if (!in_sched_functions(lr))
-			return lr;
-		fp = *(unsigned long *) (fp - 12);
+		if (!in_sched_functions(frame.pc))
+			return frame.pc;
 	} while (count ++ < 16);
 	return 0;
 }
diff --git a/arch/arm/kernel/ptrace.c b/arch/arm/kernel/ptrace.c
index df653ea5925..89882a1d018 100644
--- a/arch/arm/kernel/ptrace.c
+++ b/arch/arm/kernel/ptrace.c
@@ -653,6 +653,54 @@ static int ptrace_setcrunchregs(struct task_struct *tsk, void __user *ufp)
 }
 #endif
 
+#ifdef CONFIG_VFP
+/*
+ * Get the child VFP state.
+ */
+static int ptrace_getvfpregs(struct task_struct *tsk, void __user *data)
+{
+	struct thread_info *thread = task_thread_info(tsk);
+	union vfp_state *vfp = &thread->vfpstate;
+	struct user_vfp __user *ufp = data;
+
+	vfp_sync_state(thread);
+
+	/* copy the floating point registers */
+	if (copy_to_user(&ufp->fpregs, &vfp->hard.fpregs,
+			 sizeof(vfp->hard.fpregs)))
+		return -EFAULT;
+
+	/* copy the status and control register */
+	if (put_user(vfp->hard.fpscr, &ufp->fpscr))
+		return -EFAULT;
+
+	return 0;
+}
+
+/*
+ * Set the child VFP state.
+ */
+static int ptrace_setvfpregs(struct task_struct *tsk, void __user *data)
+{
+	struct thread_info *thread = task_thread_info(tsk);
+	union vfp_state *vfp = &thread->vfpstate;
+	struct user_vfp __user *ufp = data;
+
+	vfp_sync_state(thread);
+
+	/* copy the floating point registers */
+	if (copy_from_user(&vfp->hard.fpregs, &ufp->fpregs,
+			   sizeof(vfp->hard.fpregs)))
+		return -EFAULT;
+
+	/* copy the status and control register */
+	if (get_user(vfp->hard.fpscr, &ufp->fpscr))
+		return -EFAULT;
+
+	return 0;
+}
+#endif
+
 long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 {
 	int ret;
@@ -775,6 +823,16 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 			break;
 #endif
 
+#ifdef CONFIG_VFP
+		case PTRACE_GETVFPREGS:
+			ret = ptrace_getvfpregs(child, (void __user *)data);
+			break;
+
+		case PTRACE_SETVFPREGS:
+			ret = ptrace_setvfpregs(child, (void __user *)data);
+			break;
+#endif
+
 		default:
 			ret = ptrace_request(child, request, addr, data);
 			break;
diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index 68d6494c038..bc5e4128f9f 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -40,6 +40,7 @@
 #include <asm/mach/irq.h>
 #include <asm/mach/time.h>
 #include <asm/traps.h>
+#include <asm/unwind.h>
 
 #include "compat.h"
 #include "atags.h"
@@ -685,6 +686,8 @@ void __init setup_arch(char **cmdline_p)
 	struct machine_desc *mdesc;
 	char *from = default_command_line;
 
+	unwind_init();
+
 	setup_processor();
 	mdesc = setup_machine(machine_arch_type);
 	machine_name = mdesc->name;
@@ -780,6 +783,8 @@ static const char *hwcap_str[] = {
 	"crunch",
 	"thumbee",
 	"neon",
+	"vfpv3",
+	"vfpv3d16",
 	NULL
 };
 
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index 55fa7ff96a3..7801aac3c04 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -93,6 +93,7 @@ int __cpuinit __cpu_up(unsigned int cpu)
 	pmd = pmd_offset(pgd + pgd_index(PHYS_OFFSET), PHYS_OFFSET);
 	*pmd = __pmd((PHYS_OFFSET & PGDIR_MASK) |
 		     PMD_TYPE_SECT | PMD_SECT_AP_WRITE);
+	flush_pmd_entry(pmd);
 
 	/*
 	 * We need to tell the secondary core where to find
@@ -130,6 +131,7 @@ int __cpuinit __cpu_up(unsigned int cpu)
 	secondary_data.pgdir = 0;
 
 	*pmd = __pmd(0);
+	clean_pmd_entry(pmd);
 	pgd_free(&init_mm, pgd);
 
 	if (ret) {
diff --git a/arch/arm/kernel/stacktrace.c b/arch/arm/kernel/stacktrace.c
index fc650f64df4..9f444e5cc16 100644
--- a/arch/arm/kernel/stacktrace.c
+++ b/arch/arm/kernel/stacktrace.c
@@ -2,35 +2,60 @@
 #include <linux/sched.h>
 #include <linux/stacktrace.h>
 
-#include "stacktrace.h"
-
-int walk_stackframe(unsigned long fp, unsigned long low, unsigned long high,
-		    int (*fn)(struct stackframe *, void *), void *data)
+#include <asm/stacktrace.h>
+
+#if defined(CONFIG_FRAME_POINTER) && !defined(CONFIG_ARM_UNWIND)
+/*
+ * Unwind the current stack frame and store the new register values in the
+ * structure passed as argument. Unwinding is equivalent to a function return,
+ * hence the new PC value rather than LR should be used for backtrace.
+ *
+ * With framepointer enabled, a simple function prologue looks like this:
+ *	mov	ip, sp
+ *	stmdb	sp!, {fp, ip, lr, pc}
+ *	sub	fp, ip, #4
+ *
+ * A simple function epilogue looks like this:
+ *	ldm	sp, {fp, sp, pc}
+ *
+ * Note that with framepointer enabled, even the leaf functions have the same
+ * prologue and epilogue, therefore we can ignore the LR value in this case.
+ */
+int unwind_frame(struct stackframe *frame)
 {
-	struct stackframe *frame;
-
-	do {
-		/*
-		 * Check current frame pointer is within bounds
-		 */
-		if (fp < (low + 12) || fp + 4 >= high)
-			break;
+	unsigned long high, low;
+	unsigned long fp = frame->fp;
 
-		frame = (struct stackframe *)(fp - 12);
+	/* only go to a higher address on the stack */
+	low = frame->sp;
+	high = ALIGN(low, THREAD_SIZE) + THREAD_SIZE;
 
-		if (fn(frame, data))
-			break;
+	/* check current frame pointer is within bounds */
+	if (fp < (low + 12) || fp + 4 >= high)
+		return -EINVAL;
 
-		/*
-		 * Update the low bound - the next frame must always
-		 * be at a higher address than the current frame.
-		 */
-		low = fp + 4;
-		fp = frame->fp;
-	} while (fp);
+	/* restore the registers from the stack frame */
+	frame->fp = *(unsigned long *)(fp - 12);
+	frame->sp = *(unsigned long *)(fp - 8);
+	frame->pc = *(unsigned long *)(fp - 4);
 
 	return 0;
 }
+#endif
+
+void walk_stackframe(struct stackframe *frame,
+		     int (*fn)(struct stackframe *, void *), void *data)
+{
+	while (1) {
+		int ret;
+
+		if (fn(frame, data))
+			break;
+		ret = unwind_frame(frame);
+		if (ret < 0)
+			break;
+	}
+}
 EXPORT_SYMBOL(walk_stackframe);
 
 #ifdef CONFIG_STACKTRACE
@@ -44,7 +69,7 @@ static int save_trace(struct stackframe *frame, void *d)
 {
 	struct stack_trace_data *data = d;
 	struct stack_trace *trace = data->trace;
-	unsigned long addr = frame->lr;
+	unsigned long addr = frame->pc;
 
 	if (data->no_sched_functions && in_sched_functions(addr))
 		return 0;
@@ -61,11 +86,10 @@ static int save_trace(struct stackframe *frame, void *d)
 void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
 {
 	struct stack_trace_data data;
-	unsigned long fp, base;
+	struct stackframe frame;
 
 	data.trace = trace;
 	data.skip = trace->skip;
-	base = (unsigned long)task_stack_page(tsk);
 
 	if (tsk != current) {
 #ifdef CONFIG_SMP
@@ -76,14 +100,22 @@ void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
 		BUG();
 #else
 		data.no_sched_functions = 1;
-		fp = thread_saved_fp(tsk);
+		frame.fp = thread_saved_fp(tsk);
+		frame.sp = thread_saved_sp(tsk);
+		frame.lr = 0;		/* recovered from the stack */
+		frame.pc = thread_saved_pc(tsk);
 #endif
 	} else {
+		register unsigned long current_sp asm ("sp");
+
 		data.no_sched_functions = 0;
-		asm("mov %0, fp" : "=r" (fp));
+		frame.fp = (unsigned long)__builtin_frame_address(0);
+		frame.sp = current_sp;
+		frame.lr = (unsigned long)__builtin_return_address(0);
+		frame.pc = (unsigned long)save_stack_trace_tsk;
 	}
 
-	walk_stackframe(fp, base, base + THREAD_SIZE, save_trace, &data);
+	walk_stackframe(&frame, save_trace, &data);
 	if (trace->nr_entries < trace->max_entries)
 		trace->entries[trace->nr_entries++] = ULONG_MAX;
 }
diff --git a/arch/arm/kernel/stacktrace.h b/arch/arm/kernel/stacktrace.h
deleted file mode 100644
index e9fd20cb566..00000000000
--- a/arch/arm/kernel/stacktrace.h
+++ /dev/null
@@ -1,9 +0,0 @@
-struct stackframe {
-	unsigned long fp;
-	unsigned long sp;
-	unsigned long lr;
-	unsigned long pc;
-};
-
-int walk_stackframe(unsigned long fp, unsigned long low, unsigned long high,
-		    int (*fn)(struct stackframe *, void *), void *data);
diff --git a/arch/arm/kernel/time.c b/arch/arm/kernel/time.c
index c68b44aa88d..4cdc4a0bd02 100644
--- a/arch/arm/kernel/time.c
+++ b/arch/arm/kernel/time.c
@@ -33,6 +33,7 @@
 
 #include <asm/leds.h>
 #include <asm/thread_info.h>
+#include <asm/stacktrace.h>
 #include <asm/mach/time.h>
 
 /*
@@ -55,14 +56,22 @@ EXPORT_SYMBOL(rtc_lock);
 #ifdef CONFIG_SMP
 unsigned long profile_pc(struct pt_regs *regs)
 {
-	unsigned long fp, pc = instruction_pointer(regs);
+	struct stackframe frame;
 
-	if (in_lock_functions(pc)) {
-		fp = regs->ARM_fp;
-		pc = ((unsigned long *)fp)[-1];
-	}
+	if (!in_lock_functions(regs->ARM_pc))
+		return regs->ARM_pc;
+
+	frame.fp = regs->ARM_fp;
+	frame.sp = regs->ARM_sp;
+	frame.lr = regs->ARM_lr;
+	frame.pc = regs->ARM_pc;
+	do {
+		int ret = unwind_frame(&frame);
+		if (ret < 0)
+			return 0;
+	} while (in_lock_functions(frame.pc));
 
-	return pc;
+	return frame.pc;
 }
 EXPORT_SYMBOL(profile_pc);
 #endif
diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
index 79abc4ddc0c..57eb0f6f600 100644
--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -27,6 +27,7 @@
 #include <asm/system.h>
 #include <asm/unistd.h>
 #include <asm/traps.h>
+#include <asm/unwind.h>
 
 #include "ptrace.h"
 #include "signal.h"
@@ -61,6 +62,7 @@ void dump_backtrace_entry(unsigned long where, unsigned long from, unsigned long
 		dump_mem("Exception stack", frame + 4, frame + 4 + sizeof(struct pt_regs));
 }
 
+#ifndef CONFIG_ARM_UNWIND
 /*
  * Stack pointers should always be within the kernels view of
  * physical memory.  If it is not there, then we can't dump
@@ -74,6 +76,7 @@ static int verify_stack(unsigned long sp)
 
 	return 0;
 }
+#endif
 
 /*
  * Dump out the contents of some memory nicely...
@@ -150,13 +153,33 @@ static void dump_instr(struct pt_regs *regs)
 	set_fs(fs);
 }
 
+#ifdef CONFIG_ARM_UNWIND
+static inline void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)
+{
+	unwind_backtrace(regs, tsk);
+}
+#else
 static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)
 {
-	unsigned int fp;
+	unsigned int fp, mode;
 	int ok = 1;
 
 	printk("Backtrace: ");
-	fp = regs->ARM_fp;
+
+	if (!tsk)
+		tsk = current;
+
+	if (regs) {
+		fp = regs->ARM_fp;
+		mode = processor_mode(regs);
+	} else if (tsk != current) {
+		fp = thread_saved_fp(tsk);
+		mode = 0x10;
+	} else {
+		asm("mov %0, fp" : "=r" (fp) : : "cc");
+		mode = 0x10;
+	}
+
 	if (!fp) {
 		printk("no frame pointer");
 		ok = 0;
@@ -168,29 +191,20 @@ static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)
 	printk("\n");
 
 	if (ok)
-		c_backtrace(fp, processor_mode(regs));
+		c_backtrace(fp, mode);
 }
+#endif
 
 void dump_stack(void)
 {
-	__backtrace();
+	dump_backtrace(NULL, NULL);
 }
 
 EXPORT_SYMBOL(dump_stack);
 
 void show_stack(struct task_struct *tsk, unsigned long *sp)
 {
-	unsigned long fp;
-
-	if (!tsk)
-		tsk = current;
-
-	if (tsk != current)
-		fp = thread_saved_fp(tsk);
-	else
-		asm("mov %0, fp" : "=r" (fp) : : "cc");
-
-	c_backtrace(fp, 0x10);
+	dump_backtrace(NULL, tsk);
 	barrier();
 }
 
diff --git a/arch/arm/kernel/unwind.c b/arch/arm/kernel/unwind.c
new file mode 100644
index 00000000000..1dedc2c7ff4
--- /dev/null
+++ b/arch/arm/kernel/unwind.c
@@ -0,0 +1,434 @@
+/*
+ * arch/arm/kernel/unwind.c
+ *
+ * Copyright (C) 2008 ARM Limited
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ *
+ * Stack unwinding support for ARM
+ *
+ * An ARM EABI version of gcc is required to generate the unwind
+ * tables. For information about the structure of the unwind tables,
+ * see "Exception Handling ABI for the ARM Architecture" at:
+ *
+ * http://infocenter.arm.com/help/topic/com.arm.doc.subset.swdev.abi/index.html
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/list.h>
+
+#include <asm/stacktrace.h>
+#include <asm/traps.h>
+#include <asm/unwind.h>
+
+/* Dummy functions to avoid linker complaints */
+void __aeabi_unwind_cpp_pr0(void)
+{
+};
+EXPORT_SYMBOL(__aeabi_unwind_cpp_pr0);
+
+void __aeabi_unwind_cpp_pr1(void)
+{
+};
+EXPORT_SYMBOL(__aeabi_unwind_cpp_pr1);
+
+void __aeabi_unwind_cpp_pr2(void)
+{
+};
+EXPORT_SYMBOL(__aeabi_unwind_cpp_pr2);
+
+struct unwind_ctrl_block {
+	unsigned long vrs[16];		/* virtual register set */
+	unsigned long *insn;		/* pointer to the current instructions word */
+	int entries;			/* number of entries left to interpret */
+	int byte;			/* current byte number in the instructions word */
+};
+
+enum regs {
+	FP = 11,
+	SP = 13,
+	LR = 14,
+	PC = 15
+};
+
+extern struct unwind_idx __start_unwind_idx[];
+extern struct unwind_idx __stop_unwind_idx[];
+
+static DEFINE_SPINLOCK(unwind_lock);
+static LIST_HEAD(unwind_tables);
+
+/* Convert a prel31 symbol to an absolute address */
+#define prel31_to_addr(ptr)				\
+({							\
+	/* sign-extend to 32 bits */			\
+	long offset = (((long)*(ptr)) << 1) >> 1;	\
+	(unsigned long)(ptr) + offset;			\
+})
+
+/*
+ * Binary search in the unwind index. The entries entries are
+ * guaranteed to be sorted in ascending order by the linker.
+ */
+static struct unwind_idx *search_index(unsigned long addr,
+				       struct unwind_idx *first,
+				       struct unwind_idx *last)
+{
+	pr_debug("%s(%08lx, %p, %p)\n", __func__, addr, first, last);
+
+	if (addr < first->addr) {
+		pr_warning("unwind: Unknown symbol address %08lx\n", addr);
+		return NULL;
+	} else if (addr >= last->addr)
+		return last;
+
+	while (first < last - 1) {
+		struct unwind_idx *mid = first + ((last - first + 1) >> 1);
+
+		if (addr < mid->addr)
+			last = mid;
+		else
+			first = mid;
+	}
+
+	return first;
+}
+
+static struct unwind_idx *unwind_find_idx(unsigned long addr)
+{
+	struct unwind_idx *idx = NULL;
+	unsigned long flags;
+
+	pr_debug("%s(%08lx)\n", __func__, addr);
+
+	if (core_kernel_text(addr))
+		/* main unwind table */
+		idx = search_index(addr, __start_unwind_idx,
+				   __stop_unwind_idx - 1);
+	else {
+		/* module unwind tables */
+		struct unwind_table *table;
+
+		spin_lock_irqsave(&unwind_lock, flags);
+		list_for_each_entry(table, &unwind_tables, list) {
+			if (addr >= table->begin_addr &&
+			    addr < table->end_addr) {
+				idx = search_index(addr, table->start,
+						   table->stop - 1);
+				break;
+			}
+		}
+		spin_unlock_irqrestore(&unwind_lock, flags);
+	}
+
+	pr_debug("%s: idx = %p\n", __func__, idx);
+	return idx;
+}
+
+static unsigned long unwind_get_byte(struct unwind_ctrl_block *ctrl)
+{
+	unsigned long ret;
+
+	if (ctrl->entries <= 0) {
+		pr_warning("unwind: Corrupt unwind table\n");
+		return 0;
+	}
+
+	ret = (*ctrl->insn >> (ctrl->byte * 8)) & 0xff;
+
+	if (ctrl->byte == 0) {
+		ctrl->insn++;
+		ctrl->entries--;
+		ctrl->byte = 3;
+	} else
+		ctrl->byte--;
+
+	return ret;
+}
+
+/*
+ * Execute the current unwind instruction.
+ */
+static int unwind_exec_insn(struct unwind_ctrl_block *ctrl)
+{
+	unsigned long insn = unwind_get_byte(ctrl);
+
+	pr_debug("%s: insn = %08lx\n", __func__, insn);
+
+	if ((insn & 0xc0) == 0x00)
+		ctrl->vrs[SP] += ((insn & 0x3f) << 2) + 4;
+	else if ((insn & 0xc0) == 0x40)
+		ctrl->vrs[SP] -= ((insn & 0x3f) << 2) + 4;
+	else if ((insn & 0xf0) == 0x80) {
+		unsigned long mask;
+		unsigned long *vsp = (unsigned long *)ctrl->vrs[SP];
+		int load_sp, reg = 4;
+
+		insn = (insn << 8) | unwind_get_byte(ctrl);
+		mask = insn & 0x0fff;
+		if (mask == 0) {
+			pr_warning("unwind: 'Refuse to unwind' instruction %04lx\n",
+				   insn);
+			return -URC_FAILURE;
+		}
+
+		/* pop R4-R15 according to mask */
+		load_sp = mask & (1 << (13 - 4));
+		while (mask) {
+			if (mask & 1)
+				ctrl->vrs[reg] = *vsp++;
+			mask >>= 1;
+			reg++;
+		}
+		if (!load_sp)
+			ctrl->vrs[SP] = (unsigned long)vsp;
+	} else if ((insn & 0xf0) == 0x90 &&
+		   (insn & 0x0d) != 0x0d)
+		ctrl->vrs[SP] = ctrl->vrs[insn & 0x0f];
+	else if ((insn & 0xf0) == 0xa0) {
+		unsigned long *vsp = (unsigned long *)ctrl->vrs[SP];
+		int reg;
+
+		/* pop R4-R[4+bbb] */
+		for (reg = 4; reg <= 4 + (insn & 7); reg++)
+			ctrl->vrs[reg] = *vsp++;
+		if (insn & 0x80)
+			ctrl->vrs[14] = *vsp++;
+		ctrl->vrs[SP] = (unsigned long)vsp;
+	} else if (insn == 0xb0) {
+		ctrl->vrs[PC] = ctrl->vrs[LR];
+		/* no further processing */
+		ctrl->entries = 0;
+	} else if (insn == 0xb1) {
+		unsigned long mask = unwind_get_byte(ctrl);
+		unsigned long *vsp = (unsigned long *)ctrl->vrs[SP];
+		int reg = 0;
+
+		if (mask == 0 || mask & 0xf0) {
+			pr_warning("unwind: Spare encoding %04lx\n",
+			       (insn << 8) | mask);
+			return -URC_FAILURE;
+		}
+
+		/* pop R0-R3 according to mask */
+		while (mask) {
+			if (mask & 1)
+				ctrl->vrs[reg] = *vsp++;
+			mask >>= 1;
+			reg++;
+		}
+		ctrl->vrs[SP] = (unsigned long)vsp;
+	} else if (insn == 0xb2) {
+		unsigned long uleb128 = unwind_get_byte(ctrl);
+
+		ctrl->vrs[SP] += 0x204 + (uleb128 << 2);
+	} else {
+		pr_warning("unwind: Unhandled instruction %02lx\n", insn);
+		return -URC_FAILURE;
+	}
+
+	pr_debug("%s: fp = %08lx sp = %08lx lr = %08lx pc = %08lx\n", __func__,
+		 ctrl->vrs[FP], ctrl->vrs[SP], ctrl->vrs[LR], ctrl->vrs[PC]);
+
+	return URC_OK;
+}
+
+/*
+ * Unwind a single frame starting with *sp for the symbol at *pc. It
+ * updates the *pc and *sp with the new values.
+ */
+int unwind_frame(struct stackframe *frame)
+{
+	unsigned long high, low;
+	struct unwind_idx *idx;
+	struct unwind_ctrl_block ctrl;
+
+	/* only go to a higher address on the stack */
+	low = frame->sp;
+	high = ALIGN(low, THREAD_SIZE) + THREAD_SIZE;
+
+	pr_debug("%s(pc = %08lx lr = %08lx sp = %08lx)\n", __func__,
+		 frame->pc, frame->lr, frame->sp);
+
+	if (!kernel_text_address(frame->pc))
+		return -URC_FAILURE;
+
+	idx = unwind_find_idx(frame->pc);
+	if (!idx) {
+		pr_warning("unwind: Index not found %08lx\n", frame->pc);
+		return -URC_FAILURE;
+	}
+
+	ctrl.vrs[FP] = frame->fp;
+	ctrl.vrs[SP] = frame->sp;
+	ctrl.vrs[LR] = frame->lr;
+	ctrl.vrs[PC] = 0;
+
+	if (idx->insn == 1)
+		/* can't unwind */
+		return -URC_FAILURE;
+	else if ((idx->insn & 0x80000000) == 0)
+		/* prel31 to the unwind table */
+		ctrl.insn = (unsigned long *)prel31_to_addr(&idx->insn);
+	else if ((idx->insn & 0xff000000) == 0x80000000)
+		/* only personality routine 0 supported in the index */
+		ctrl.insn = &idx->insn;
+	else {
+		pr_warning("unwind: Unsupported personality routine %08lx in the index at %p\n",
+			   idx->insn, idx);
+		return -URC_FAILURE;
+	}
+
+	/* check the personality routine */
+	if ((*ctrl.insn & 0xff000000) == 0x80000000) {
+		ctrl.byte = 2;
+		ctrl.entries = 1;
+	} else if ((*ctrl.insn & 0xff000000) == 0x81000000) {
+		ctrl.byte = 1;
+		ctrl.entries = 1 + ((*ctrl.insn & 0x00ff0000) >> 16);
+	} else {
+		pr_warning("unwind: Unsupported personality routine %08lx at %p\n",
+			   *ctrl.insn, ctrl.insn);
+		return -URC_FAILURE;
+	}
+
+	while (ctrl.entries > 0) {
+		int urc;
+
+		if (ctrl.vrs[SP] < low || ctrl.vrs[SP] >= high)
+			return -URC_FAILURE;
+		urc = unwind_exec_insn(&ctrl);
+		if (urc < 0)
+			return urc;
+	}
+
+	if (ctrl.vrs[PC] == 0)
+		ctrl.vrs[PC] = ctrl.vrs[LR];
+
+	frame->fp = ctrl.vrs[FP];
+	frame->sp = ctrl.vrs[SP];
+	frame->lr = ctrl.vrs[LR];
+	frame->pc = ctrl.vrs[PC];
+
+	return URC_OK;
+}
+
+void unwind_backtrace(struct pt_regs *regs, struct task_struct *tsk)
+{
+	struct stackframe frame;
+	unsigned long high, low;
+	register unsigned long current_sp asm ("sp");
+
+	pr_debug("%s(regs = %p tsk = %p)\n", __func__, regs, tsk);
+
+	if (!tsk)
+		tsk = current;
+
+	if (regs) {
+		frame.fp = regs->ARM_fp;
+		frame.sp = regs->ARM_sp;
+		frame.lr = regs->ARM_lr;
+		frame.pc = regs->ARM_pc;
+	} else if (tsk == current) {
+		frame.fp = (unsigned long)__builtin_frame_address(0);
+		frame.sp = current_sp;
+		frame.lr = (unsigned long)__builtin_return_address(0);
+		frame.pc = (unsigned long)unwind_backtrace;
+	} else {
+		/* task blocked in __switch_to */
+		frame.fp = thread_saved_fp(tsk);
+		frame.sp = thread_saved_sp(tsk);
+		/*
+		 * The function calling __switch_to cannot be a leaf function
+		 * so LR is recovered from the stack.
+		 */
+		frame.lr = 0;
+		frame.pc = thread_saved_pc(tsk);
+	}
+
+	low = frame.sp & ~(THREAD_SIZE - 1);
+	high = low + THREAD_SIZE;
+
+	while (1) {
+		int urc;
+		unsigned long where = frame.pc;
+
+		urc = unwind_frame(&frame);
+		if (urc < 0)
+			break;
+		dump_backtrace_entry(where, frame.pc, frame.sp - 4);
+	}
+}
+
+struct unwind_table *unwind_table_add(unsigned long start, unsigned long size,
+				      unsigned long text_addr,
+				      unsigned long text_size)
+{
+	unsigned long flags;
+	struct unwind_idx *idx;
+	struct unwind_table *tab = kmalloc(sizeof(*tab), GFP_KERNEL);
+
+	pr_debug("%s(%08lx, %08lx, %08lx, %08lx)\n", __func__, start, size,
+		 text_addr, text_size);
+
+	if (!tab)
+		return tab;
+
+	tab->start = (struct unwind_idx *)start;
+	tab->stop = (struct unwind_idx *)(start + size);
+	tab->begin_addr = text_addr;
+	tab->end_addr = text_addr + text_size;
+
+	/* Convert the symbol addresses to absolute values */
+	for (idx = tab->start; idx < tab->stop; idx++)
+		idx->addr = prel31_to_addr(&idx->addr);
+
+	spin_lock_irqsave(&unwind_lock, flags);
+	list_add_tail(&tab->list, &unwind_tables);
+	spin_unlock_irqrestore(&unwind_lock, flags);
+
+	return tab;
+}
+
+void unwind_table_del(struct unwind_table *tab)
+{
+	unsigned long flags;
+
+	if (!tab)
+		return;
+
+	spin_lock_irqsave(&unwind_lock, flags);
+	list_del(&tab->list);
+	spin_unlock_irqrestore(&unwind_lock, flags);
+
+	kfree(tab);
+}
+
+int __init unwind_init(void)
+{
+	struct unwind_idx *idx;
+
+	/* Convert the symbol addresses to absolute values */
+	for (idx = __start_unwind_idx; idx < __stop_unwind_idx; idx++)
+		idx->addr = prel31_to_addr(&idx->addr);
+
+	pr_debug("unwind: ARM stack unwinding initialised\n");
+
+	return 0;
+}
diff --git a/arch/arm/kernel/vmlinux.lds.S b/arch/arm/kernel/vmlinux.lds.S
index 1602373e539..c90f27250ea 100644
--- a/arch/arm/kernel/vmlinux.lds.S
+++ b/arch/arm/kernel/vmlinux.lds.S
@@ -82,6 +82,8 @@ SECTIONS
 		EXIT_TEXT
 		EXIT_DATA
 		*(.exitcall.exit)
+		*(.ARM.exidx.exit.text)
+		*(.ARM.extab.exit.text)
 #ifndef CONFIG_MMU
 		*(.fixup)
 		*(__ex_table)
@@ -112,6 +114,23 @@ SECTIONS
 
 	_etext = .;			/* End of text and rodata section */
 
+#ifdef CONFIG_ARM_UNWIND
+	/*
+	 * Stack unwinding tables
+	 */
+	. = ALIGN(8);
+	.ARM.unwind_idx : {
+		__start_unwind_idx = .;
+		*(.ARM.exidx*)
+		__stop_unwind_idx = .;
+	}
+	.ARM.unwind_tab : {
+		__start_unwind_tab = .;
+		*(.ARM.extab*)
+		__stop_unwind_tab = .;
+	}
+#endif
+
 #ifdef CONFIG_XIP_KERNEL
 	__data_loc = ALIGN(4);		/* location in binary */
 	. = PAGE_OFFSET + TEXT_OFFSET;