Merge branch 'korg-android-3.1' into korg-android+linux-tegra-3.1

Conflicts:
	arch/arm/mm/cache-l2x0.c
	drivers/misc/Kconfig
	drivers/misc/Makefile

Signed-off-by: Dan Willemsen <dwillemsen@nvidia.com>

6 files changed, 1553 insertions, 0 deletions

diff --git a/arch/arm/common/Kconfig b/arch/arm/common/Kconfig
index 4b71766fb21d..638256600ffe 100644
--- a/arch/arm/common/Kconfig
+++ b/arch/arm/common/Kconfig
@@ -39,3 +39,53 @@ config SHARP_PARAM
 
 config SHARP_SCOOP
 	bool
+
+config FIQ_GLUE
+	bool
+	select FIQ
+
+config FIQ_DEBUGGER
+	bool "FIQ Mode Serial Debugger"
+	select FIQ
+	select FIQ_GLUE
+	default n
+	help
+	  The FIQ serial debugger can accept commands even when the
+	  kernel is unresponsive due to being stuck with interrupts
+	  disabled.
+
+
+config FIQ_DEBUGGER_NO_SLEEP
+	bool "Keep serial debugger active"
+	depends on FIQ_DEBUGGER
+	default n
+	help
+	  Enables the serial debugger at boot. Passing
+	  fiq_debugger.no_sleep on the kernel commandline will
+	  override this config option.
+
+config FIQ_DEBUGGER_WAKEUP_IRQ_ALWAYS_ON
+	bool "Don't disable wakeup IRQ when debugger is active"
+	depends on FIQ_DEBUGGER
+	default n
+	help
+	  Don't disable the wakeup irq when enabling the uart clock.  This will
+	  cause extra interrupts, but it makes the serial debugger usable with
+	  on some MSM radio builds that ignore the uart clock request in power
+	  collapse.
+
+config FIQ_DEBUGGER_CONSOLE
+	bool "Console on FIQ Serial Debugger port"
+	depends on FIQ_DEBUGGER
+	default n
+	help
+	  Enables a console so that printk messages are displayed on
+	  the debugger serial port as the occur.
+
+config FIQ_DEBUGGER_CONSOLE_DEFAULT_ENABLE
+	bool "Put the FIQ debugger into console mode by default"
+	depends on FIQ_DEBUGGER_CONSOLE
+	default n
+	help
+	  If enabled, this puts the fiq debugger into console mode by default.
+	  Otherwise, the fiq debugger will start out in debug mode.
diff --git a/arch/arm/common/Makefile b/arch/arm/common/Makefile
index 6ea9b6f3607a..3ab5d765fedd 100644
--- a/arch/arm/common/Makefile
+++ b/arch/arm/common/Makefile
@@ -17,3 +17,5 @@ obj-$(CONFIG_ARCH_IXP2000)	+= uengine.o
 obj-$(CONFIG_ARCH_IXP23XX)	+= uengine.o
 obj-$(CONFIG_PCI_HOST_ITE8152)  += it8152.o
 obj-$(CONFIG_ARM_TIMER_SP804)	+= timer-sp.o
+obj-$(CONFIG_FIQ_GLUE)		+= fiq_glue.o fiq_glue_setup.o
+obj-$(CONFIG_FIQ_DEBUGGER)	+= fiq_debugger.o
diff --git a/arch/arm/common/fiq_debugger.c b/arch/arm/common/fiq_debugger.c
new file mode 100644
index 000000000000..3ed18ae2ed80
--- /dev/null
+++ b/arch/arm/common/fiq_debugger.c
@@ -0,0 +1,1196 @@
+/*
+ * arch/arm/common/fiq_debugger.c
+ *
+ * Serial Debugger Interface accessed through an FIQ interrupt.
+ *
+ * Copyright (C) 2008 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ */
+
+#include <stdarg.h>
+#include <linux/module.h>
+#include <linux/io.h>
+#include <linux/console.h>
+#include <linux/interrupt.h>
+#include <linux/clk.h>
+#include <linux/platform_device.h>
+#include <linux/kernel_stat.h>
+#include <linux/irq.h>
+#include <linux/delay.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/smp.h>
+#include <linux/timer.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/wakelock.h>
+
+#include <asm/fiq_debugger.h>
+#include <asm/fiq_glue.h>
+#include <asm/stacktrace.h>
+
+#include <mach/system.h>
+
+#include <linux/uaccess.h>
+
+#include "fiq_debugger_ringbuf.h"
+
+#define DEBUG_MAX 64
+#define MAX_UNHANDLED_FIQ_COUNT 1000000
+
+#define THREAD_INFO(sp) ((struct thread_info *) \
+		((unsigned long)(sp) & ~(THREAD_SIZE - 1)))
+
+struct fiq_debugger_state {
+	struct fiq_glue_handler handler;
+
+	int fiq;
+	int uart_irq;
+	int signal_irq;
+	int wakeup_irq;
+	bool wakeup_irq_no_set_wake;
+	struct clk *clk;
+	struct fiq_debugger_pdata *pdata;
+	struct platform_device *pdev;
+
+	char debug_cmd[DEBUG_MAX];
+	int debug_busy;
+	int debug_abort;
+
+	char debug_buf[DEBUG_MAX];
+	int debug_count;
+
+	bool no_sleep;
+	bool debug_enable;
+	bool ignore_next_wakeup_irq;
+	struct timer_list sleep_timer;
+	spinlock_t sleep_timer_lock;
+	bool uart_enabled;
+	struct wake_lock debugger_wake_lock;
+	bool console_enable;
+	int current_cpu;
+	atomic_t unhandled_fiq_count;
+	bool in_fiq;
+
+#ifdef CONFIG_FIQ_DEBUGGER_CONSOLE
+	struct console console;
+	struct tty_driver *tty_driver;
+	struct tty_struct *tty;
+	int tty_open_count;
+	struct fiq_debugger_ringbuf *tty_rbuf;
+	bool syslog_dumping;
+#endif
+
+	unsigned int last_irqs[NR_IRQS];
+	unsigned int last_local_timer_irqs[NR_CPUS];
+};
+
+#ifdef CONFIG_FIQ_DEBUGGER_NO_SLEEP
+static bool initial_no_sleep = true;
+#else
+static bool initial_no_sleep;
+#endif
+
+#ifdef CONFIG_FIQ_DEBUGGER_CONSOLE_DEFAULT_ENABLE
+static bool initial_debug_enable = true;
+static bool initial_console_enable = true;
+#else
+static bool initial_debug_enable;
+static bool initial_console_enable;
+#endif
+
+module_param_named(no_sleep, initial_no_sleep, bool, 0644);
+module_param_named(debug_enable, initial_debug_enable, bool, 0644);
+module_param_named(console_enable, initial_console_enable, bool, 0644);
+
+#ifdef CONFIG_FIQ_DEBUGGER_WAKEUP_IRQ_ALWAYS_ON
+static inline void enable_wakeup_irq(struct fiq_debugger_state *state) {}
+static inline void disable_wakeup_irq(struct fiq_debugger_state *state) {}
+#else
+static inline void enable_wakeup_irq(struct fiq_debugger_state *state)
+{
+	if (state->wakeup_irq < 0)
+		return;
+	enable_irq(state->wakeup_irq);
+	if (!state->wakeup_irq_no_set_wake)
+		enable_irq_wake(state->wakeup_irq);
+}
+static inline void disable_wakeup_irq(struct fiq_debugger_state *state)
+{
+	if (state->wakeup_irq < 0)
+		return;
+	disable_irq_nosync(state->wakeup_irq);
+	if (!state->wakeup_irq_no_set_wake)
+		disable_irq_wake(state->wakeup_irq);
+}
+#endif
+
+static bool inline debug_have_fiq(struct fiq_debugger_state *state)
+{
+	return (state->fiq >= 0);
+}
+
+static void debug_force_irq(struct fiq_debugger_state *state)
+{
+	unsigned int irq = state->signal_irq;
+
+	if (WARN_ON(!debug_have_fiq(state)))
+		return;
+	if (state->pdata->force_irq) {
+		state->pdata->force_irq(state->pdev, irq);
+	} else {
+		struct irq_chip *chip = irq_get_chip(irq);
+		if (chip && chip->irq_retrigger)
+			chip->irq_retrigger(irq_get_irq_data(irq));
+	}
+}
+
+static void debug_uart_enable(struct fiq_debugger_state *state)
+{
+	if (state->clk)
+		clk_enable(state->clk);
+	if (state->pdata->uart_enable)
+		state->pdata->uart_enable(state->pdev);
+}
+
+static void debug_uart_disable(struct fiq_debugger_state *state)
+{
+	if (state->pdata->uart_disable)
+		state->pdata->uart_disable(state->pdev);
+	if (state->clk)
+		clk_disable(state->clk);
+}
+
+static void debug_uart_flush(struct fiq_debugger_state *state)
+{
+	if (state->pdata->uart_flush)
+		state->pdata->uart_flush(state->pdev);
+}
+
+static void debug_puts(struct fiq_debugger_state *state, char *s)
+{
+	unsigned c;
+	while ((c = *s++)) {
+		if (c == '\n')
+			state->pdata->uart_putc(state->pdev, '\r');
+		state->pdata->uart_putc(state->pdev, c);
+	}
+}
+
+static void debug_prompt(struct fiq_debugger_state *state)
+{
+	debug_puts(state, "debug> ");
+}
+
+int log_buf_copy(char *dest, int idx, int len);
+static void dump_kernel_log(struct fiq_debugger_state *state)
+{
+	char buf[1024];
+	int idx = 0;
+	int ret;
+	int saved_oip;
+
+	/* setting oops_in_progress prevents log_buf_copy()
+	 * from trying to take a spinlock which will make it
+	 * very unhappy in some cases...
+	 */
+	saved_oip = oops_in_progress;
+	oops_in_progress = 1;
+	for (;;) {
+		ret = log_buf_copy(buf, idx, 1023);
+		if (ret <= 0)
+			break;
+		buf[ret] = 0;
+		debug_puts(state, buf);
+		idx += ret;
+	}
+	oops_in_progress = saved_oip;
+}
+
+static char *mode_name(unsigned cpsr)
+{
+	switch (cpsr & MODE_MASK) {
+	case USR_MODE: return "USR";
+	case FIQ_MODE: return "FIQ";
+	case IRQ_MODE: return "IRQ";
+	case SVC_MODE: return "SVC";
+	case ABT_MODE: return "ABT";
+	case UND_MODE: return "UND";
+	case SYSTEM_MODE: return "SYS";
+	default: return "???";
+	}
+}
+
+static int debug_printf(void *cookie, const char *fmt, ...)
+{
+	struct fiq_debugger_state *state = cookie;
+	char buf[256];
+	va_list ap;
+
+	va_start(ap, fmt);
+	vsnprintf(buf, sizeof(buf), fmt, ap);
+	va_end(ap);
+
+	debug_puts(state, buf);
+	return state->debug_abort;
+}
+
+/* Safe outside fiq context */
+static int debug_printf_nfiq(void *cookie, const char *fmt, ...)
+{
+	struct fiq_debugger_state *state = cookie;
+	char buf[256];
+	va_list ap;
+	unsigned long irq_flags;
+
+	va_start(ap, fmt);
+	vsnprintf(buf, 128, fmt, ap);
+	va_end(ap);
+
+	local_irq_save(irq_flags);
+	debug_puts(state, buf);
+	debug_uart_flush(state);
+	local_irq_restore(irq_flags);
+	return state->debug_abort;
+}
+
+static void dump_regs(struct fiq_debugger_state *state, unsigned *regs)
+{
+	debug_printf(state, " r0 %08x  r1 %08x  r2 %08x  r3 %08x\n",
+			regs[0], regs[1], regs[2], regs[3]);
+	debug_printf(state, " r4 %08x  r5 %08x  r6 %08x  r7 %08x\n",
+			regs[4], regs[5], regs[6], regs[7]);
+	debug_printf(state, " r8 %08x  r9 %08x r10 %08x r11 %08x  mode %s\n",
+			regs[8], regs[9], regs[10], regs[11],
+			mode_name(regs[16]));
+	if ((regs[16] & MODE_MASK) == USR_MODE)
+		debug_printf(state, " ip %08x  sp %08x  lr %08x  pc %08x  "
+				"cpsr %08x\n", regs[12], regs[13], regs[14],
+				regs[15], regs[16]);
+	else
+		debug_printf(state, " ip %08x  sp %08x  lr %08x  pc %08x  "
+				"cpsr %08x  spsr %08x\n", regs[12], regs[13],
+				regs[14], regs[15], regs[16], regs[17]);
+}
+
+struct mode_regs {
+	unsigned long sp_svc;
+	unsigned long lr_svc;
+	unsigned long spsr_svc;
+
+	unsigned long sp_abt;
+	unsigned long lr_abt;
+	unsigned long spsr_abt;
+
+	unsigned long sp_und;
+	unsigned long lr_und;
+	unsigned long spsr_und;
+
+	unsigned long sp_irq;
+	unsigned long lr_irq;
+	unsigned long spsr_irq;
+
+	unsigned long r8_fiq;
+	unsigned long r9_fiq;
+	unsigned long r10_fiq;
+	unsigned long r11_fiq;
+	unsigned long r12_fiq;
+	unsigned long sp_fiq;
+	unsigned long lr_fiq;
+	unsigned long spsr_fiq;
+};
+
+void __naked get_mode_regs(struct mode_regs *regs)
+{
+	asm volatile (
+	"mrs	r1, cpsr\n"
+	"msr	cpsr_c, #0xd3 @(SVC_MODE | PSR_I_BIT | PSR_F_BIT)\n"
+	"stmia	r0!, {r13 - r14}\n"
+	"mrs	r2, spsr\n"
+	"msr	cpsr_c, #0xd7 @(ABT_MODE | PSR_I_BIT | PSR_F_BIT)\n"
+	"stmia	r0!, {r2, r13 - r14}\n"
+	"mrs	r2, spsr\n"
+	"msr	cpsr_c, #0xdb @(UND_MODE | PSR_I_BIT | PSR_F_BIT)\n"
+	"stmia	r0!, {r2, r13 - r14}\n"
+	"mrs	r2, spsr\n"
+	"msr	cpsr_c, #0xd2 @(IRQ_MODE | PSR_I_BIT | PSR_F_BIT)\n"
+	"stmia	r0!, {r2, r13 - r14}\n"
+	"mrs	r2, spsr\n"
+	"msr	cpsr_c, #0xd1 @(FIQ_MODE | PSR_I_BIT | PSR_F_BIT)\n"
+	"stmia	r0!, {r2, r8 - r14}\n"
+	"mrs	r2, spsr\n"
+	"stmia	r0!, {r2}\n"
+	"msr	cpsr_c, r1\n"
+	"bx	lr\n");
+}
+
+
+static void dump_allregs(struct fiq_debugger_state *state, unsigned *regs)
+{
+	struct mode_regs mode_regs;
+	dump_regs(state, regs);
+	get_mode_regs(&mode_regs);
+	debug_printf(state, " svc: sp %08x  lr %08x  spsr %08x\n",
+			mode_regs.sp_svc, mode_regs.lr_svc, mode_regs.spsr_svc);
+	debug_printf(state, " abt: sp %08x  lr %08x  spsr %08x\n",
+			mode_regs.sp_abt, mode_regs.lr_abt, mode_regs.spsr_abt);
+	debug_printf(state, " und: sp %08x  lr %08x  spsr %08x\n",
+			mode_regs.sp_und, mode_regs.lr_und, mode_regs.spsr_und);
+	debug_printf(state, " irq: sp %08x  lr %08x  spsr %08x\n",
+			mode_regs.sp_irq, mode_regs.lr_irq, mode_regs.spsr_irq);
+	debug_printf(state, " fiq: r8 %08x  r9 %08x  r10 %08x  r11 %08x  "
+			"r12 %08x\n",
+			mode_regs.r8_fiq, mode_regs.r9_fiq, mode_regs.r10_fiq,
+			mode_regs.r11_fiq, mode_regs.r12_fiq);
+	debug_printf(state, " fiq: sp %08x  lr %08x  spsr %08x\n",
+			mode_regs.sp_fiq, mode_regs.lr_fiq, mode_regs.spsr_fiq);
+}
+
+static void dump_irqs(struct fiq_debugger_state *state)
+{
+	int n;
+	unsigned int cpu;
+
+	debug_printf(state, "irqnr       total  since-last   status  name\n");
+	for (n = 0; n < NR_IRQS; n++) {
+		struct irqaction *act = irq_desc[n].action;
+		if (!act && !kstat_irqs(n))
+			continue;
+		debug_printf(state, "%5d: %10u %11u %8x  %s\n", n,
+			kstat_irqs(n),
+			kstat_irqs(n) - state->last_irqs[n],
+			irq_desc[n].status_use_accessors,
+			(act && act->name) ? act->name : "???");
+		state->last_irqs[n] = kstat_irqs(n);
+	}
+
+	for (cpu = 0; cpu < NR_CPUS; cpu++) {
+
+		debug_printf(state, "LOC %d: %10u %11u\n", cpu,
+			     __IRQ_STAT(cpu, local_timer_irqs),
+			     __IRQ_STAT(cpu, local_timer_irqs) -
+			     state->last_local_timer_irqs[cpu]);
+		state->last_local_timer_irqs[cpu] =
+			__IRQ_STAT(cpu, local_timer_irqs);
+	}
+}
+
+struct stacktrace_state {
+	struct fiq_debugger_state *state;
+	unsigned int depth;
+};
+
+static int report_trace(struct stackframe *frame, void *d)
+{
+	struct stacktrace_state *sts = d;
+
+	if (sts->depth) {
+		debug_printf(sts->state,
+			"  pc: %p (%pF), lr %p (%pF), sp %p, fp %p\n",
+			frame->pc, frame->pc, frame->lr, frame->lr,
+			frame->sp, frame->fp);
+		sts->depth--;
+		return 0;
+	}
+	debug_printf(sts->state, "  ...\n");
+
+	return sts->depth == 0;
+}
+
+struct frame_tail {
+	struct frame_tail *fp;
+	unsigned long sp;
+	unsigned long lr;
+} __attribute__((packed));
+
+static struct frame_tail *user_backtrace(struct fiq_debugger_state *state,
+					struct frame_tail *tail)
+{
+	struct frame_tail buftail[2];
+
+	/* Also check accessibility of one struct frame_tail beyond */
+	if (!access_ok(VERIFY_READ, tail, sizeof(buftail))) {
+		debug_printf(state, "  invalid frame pointer %p\n", tail);
+		return NULL;
+	}
+	if (__copy_from_user_inatomic(buftail, tail, sizeof(buftail))) {
+		debug_printf(state,
+			"  failed to copy frame pointer %p\n", tail);
+		return NULL;
+	}
+
+	debug_printf(state, "  %p\n", buftail[0].lr);
+
+	/* frame pointers should strictly progress back up the stack
+	 * (towards higher addresses) */
+	if (tail >= buftail[0].fp)
+		return NULL;
+
+	return buftail[0].fp-1;
+}
+
+void dump_stacktrace(struct fiq_debugger_state *state,
+		struct pt_regs * const regs, unsigned int depth, void *ssp)
+{
+	struct frame_tail *tail;
+	struct thread_info *real_thread_info = THREAD_INFO(ssp);
+	struct stacktrace_state sts;
+
+	sts.depth = depth;
+	sts.state = state;
+	*current_thread_info() = *real_thread_info;
+
+	if (!current)
+		debug_printf(state, "current NULL\n");
+	else
+		debug_printf(state, "pid: %d  comm: %s\n",
+			current->pid, current->comm);
+	dump_regs(state, (unsigned *)regs);
+
+	if (!user_mode(regs)) {
+		struct stackframe frame;
+		frame.fp = regs->ARM_fp;
+		frame.sp = regs->ARM_sp;
+		frame.lr = regs->ARM_lr;
+		frame.pc = regs->ARM_pc;
+		debug_printf(state,
+			"  pc: %p (%pF), lr %p (%pF), sp %p, fp %p\n",
+			regs->ARM_pc, regs->ARM_pc, regs->ARM_lr, regs->ARM_lr,
+			regs->ARM_sp, regs->ARM_fp);
+		walk_stackframe(&frame, report_trace, &sts);
+		return;
+	}
+
+	tail = ((struct frame_tail *) regs->ARM_fp) - 1;
+	while (depth-- && tail && !((unsigned long) tail & 3))
+		tail = user_backtrace(state, tail);
+}
+
+static void do_ps(struct fiq_debugger_state *state)
+{
+	struct task_struct *g;
+	struct task_struct *p;
+	unsigned task_state;
+	static const char stat_nam[] = "RSDTtZX";
+
+	debug_printf(state, "pid   ppid  prio task            pc\n");
+	read_lock(&tasklist_lock);
+	do_each_thread(g, p) {
+		task_state = p->state ? __ffs(p->state) + 1 : 0;
+		debug_printf(state,
+			     "%5d %5d %4d ", p->pid, p->parent->pid, p->prio);
+		debug_printf(state, "%-13.13s %c", p->comm,
+			     task_state >= sizeof(stat_nam) ? '?' : stat_nam[task_state]);
+		if (task_state == TASK_RUNNING)
+			debug_printf(state, " running\n");
+		else
+			debug_printf(state, " %08lx\n", thread_saved_pc(p));
+	} while_each_thread(g, p);
+	read_unlock(&tasklist_lock);
+}
+
+#ifdef CONFIG_FIQ_DEBUGGER_CONSOLE
+static void begin_syslog_dump(struct fiq_debugger_state *state)
+{
+	state->syslog_dumping = true;
+}
+
+static void end_syslog_dump(struct fiq_debugger_state *state)
+{
+	state->syslog_dumping = false;
+}
+#else
+extern int do_syslog(int type, char __user *bug, int count);
+static void begin_syslog_dump(struct fiq_debugger_state *state)
+{
+	do_syslog(5 /* clear */, NULL, 0);
+}
+
+static void end_syslog_dump(struct fiq_debugger_state *state)
+{
+	char buf[128];
+	int ret;
+	int idx = 0;
+
+	while (1) {
+		ret = log_buf_copy(buf, idx, sizeof(buf) - 1);
+		if (ret <= 0)
+			break;
+		buf[ret] = 0;
+		debug_printf(state, "%s", buf);
+		idx += ret;
+	}
+}
+#endif
+
+static void do_sysrq(struct fiq_debugger_state *state, char rq)
+{
+	begin_syslog_dump(state);
+	handle_sysrq(rq);
+	end_syslog_dump(state);
+}
+
+/* This function CANNOT be called in FIQ context */
+static void debug_irq_exec(struct fiq_debugger_state *state, char *cmd)
+{
+	if (!strcmp(cmd, "ps"))
+		do_ps(state);
+	if (!strcmp(cmd, "sysrq"))
+		do_sysrq(state, 'h');
+	if (!strncmp(cmd, "sysrq ", 6))
+		do_sysrq(state, cmd[6]);
+}
+
+static void debug_help(struct fiq_debugger_state *state)
+{
+	debug_printf(state,	"FIQ Debugger commands:\n"
+				" pc            PC status\n"
+				" regs          Register dump\n"
+				" allregs       Extended Register dump\n"
+				" bt            Stack trace\n"
+				" reboot        Reboot\n"
+				" irqs          Interupt status\n"
+				" kmsg          Kernel log\n"
+				" version       Kernel version\n");
+	debug_printf(state,	" sleep         Allow sleep while in FIQ\n"
+				" nosleep       Disable sleep while in FIQ\n"
+				" console       Switch terminal to console\n"
+				" cpu           Current CPU\n"
+				" cpu <number>  Switch to CPU<number>\n");
+	debug_printf(state,	" ps            Process list\n"
+				" sysrq         sysrq options\n"
+				" sysrq <param> Execute sysrq with <param>\n");
+}
+
+static void take_affinity(void *info)
+{
+	struct fiq_debugger_state *state = info;
+	struct cpumask cpumask;
+
+	cpumask_clear(&cpumask);
+	cpumask_set_cpu(get_cpu(), &cpumask);
+
+	irq_set_affinity(state->uart_irq, &cpumask);
+}
+
+static void switch_cpu(struct fiq_debugger_state *state, int cpu)
+{
+	if (!debug_have_fiq(state))
+		smp_call_function_single(cpu, take_affinity, state, false);
+	state->current_cpu = cpu;
+}
+
+static bool debug_fiq_exec(struct fiq_debugger_state *state,
+			const char *cmd, unsigned *regs, void *svc_sp)
+{
+	bool signal_helper = false;
+
+	if (!strcmp(cmd, "help") || !strcmp(cmd, "?")) {
+		debug_help(state);
+	} else if (!strcmp(cmd, "pc")) {
+		debug_printf(state, " pc %08x cpsr %08x mode %s\n",
+			regs[15], regs[16], mode_name(regs[16]));
+	} else if (!strcmp(cmd, "regs")) {
+		dump_regs(state, regs);
+	} else if (!strcmp(cmd, "allregs")) {
+		dump_allregs(state, regs);
+	} else if (!strcmp(cmd, "bt")) {
+		dump_stacktrace(state, (struct pt_regs *)regs, 100, svc_sp);
+	} else if (!strcmp(cmd, "reboot")) {
+		arch_reset(0, 0);
+	} else if (!strcmp(cmd, "irqs")) {
+		dump_irqs(state);
+	} else if (!strcmp(cmd, "kmsg")) {
+		dump_kernel_log(state);
+	} else if (!strcmp(cmd, "version")) {
+		debug_printf(state, "%s\n", linux_banner);
+	} else if (!strcmp(cmd, "sleep")) {
+		state->no_sleep = false;
+		debug_printf(state, "enabling sleep\n");
+	} else if (!strcmp(cmd, "nosleep")) {
+		state->no_sleep = true;
+		debug_printf(state, "disabling sleep\n");
+	} else if (!strcmp(cmd, "console")) {
+		state->console_enable = true;
+		debug_printf(state, "console mode\n");
+	} else if (!strcmp(cmd, "cpu")) {
+		debug_printf(state, "cpu %d\n", state->current_cpu);
+	} else if (!strncmp(cmd, "cpu ", 4)) {
+		unsigned long cpu = 0;
+		if (strict_strtoul(cmd + 4, 10, &cpu) == 0)
+			switch_cpu(state, cpu);
+		else
+			debug_printf(state, "invalid cpu\n");
+		debug_printf(state, "cpu %d\n", state->current_cpu);
+	} else {
+		if (state->debug_busy) {
+			debug_printf(state,
+				"command processor busy. trying to abort.\n");
+			state->debug_abort = -1;
+		} else {
+			strcpy(state->debug_cmd, cmd);
+			state->debug_busy = 1;
+		}
+
+		return true;
+	}
+	if (!state->console_enable)
+		debug_prompt(state);
+
+	return signal_helper;
+}
+
+static void sleep_timer_expired(unsigned long data)
+{
+	struct fiq_debugger_state *state = (struct fiq_debugger_state *)data;
+	unsigned long flags;
+
+	spin_lock_irqsave(&state->sleep_timer_lock, flags);
+	if (state->uart_enabled && !state->no_sleep) {
+		if (state->debug_enable && !state->console_enable) {
+			state->debug_enable = false;
+			debug_printf_nfiq(state, "suspending fiq debugger\n");
+		}
+		state->ignore_next_wakeup_irq = true;
+		debug_uart_disable(state);
+		state->uart_enabled = false;
+		enable_wakeup_irq(state);
+	}
+	wake_unlock(&state->debugger_wake_lock);
+	spin_unlock_irqrestore(&state->sleep_timer_lock, flags);
+}
+
+static void handle_wakeup(struct fiq_debugger_state *state)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&state->sleep_timer_lock, flags);
+	if (state->wakeup_irq >= 0 && state->ignore_next_wakeup_irq) {
+		state->ignore_next_wakeup_irq = false;
+	} else if (!state->uart_enabled) {
+		wake_lock(&state->debugger_wake_lock);
+		debug_uart_enable(state);
+		state->uart_enabled = true;
+		disable_wakeup_irq(state);
+		mod_timer(&state->sleep_timer, jiffies + HZ / 2);
+	}
+	spin_unlock_irqrestore(&state->sleep_timer_lock, flags);
+}
+
+static irqreturn_t wakeup_irq_handler(int irq, void *dev)
+{
+	struct fiq_debugger_state *state = dev;
+
+	if (!state->no_sleep)
+		debug_puts(state, "WAKEUP\n");
+	handle_wakeup(state);
+
+	return IRQ_HANDLED;
+}
+
+
+static void debug_handle_irq_context(struct fiq_debugger_state *state)
+{
+	if (!state->no_sleep) {
+		unsigned long flags;
+
+		spin_lock_irqsave(&state->sleep_timer_lock, flags);
+		wake_lock(&state->debugger_wake_lock);
+		mod_timer(&state->sleep_timer, jiffies + HZ * 5);
+		spin_unlock_irqrestore(&state->sleep_timer_lock, flags);
+	}
+#if defined(CONFIG_FIQ_DEBUGGER_CONSOLE)
+	if (state->tty) {
+		int i;
+		int count = fiq_debugger_ringbuf_level(state->tty_rbuf);
+		for (i = 0; i < count; i++) {
+			int c = fiq_debugger_ringbuf_peek(state->tty_rbuf, 0);
+			tty_insert_flip_char(state->tty, c, TTY_NORMAL);
+			if (!fiq_debugger_ringbuf_consume(state->tty_rbuf, 1))
+				pr_warn("fiq tty failed to consume byte\n");
+		}
+		tty_flip_buffer_push(state->tty);
+	}
+#endif
+	if (state->debug_busy) {
+		debug_irq_exec(state, state->debug_cmd);
+		debug_prompt(state);
+		state->debug_busy = 0;
+	}
+}
+
+static int debug_getc(struct fiq_debugger_state *state)
+{
+	return state->pdata->uart_getc(state->pdev);
+}
+
+static bool debug_handle_uart_interrupt(struct fiq_debugger_state *state,
+			int this_cpu, void *regs, void *svc_sp)
+{
+	int c;
+	static int last_c;
+	int count = 0;
+	bool signal_helper = false;
+
+	if (this_cpu != state->current_cpu) {
+		if (state->in_fiq)
+			return false;
+
+		if (atomic_inc_return(&state->unhandled_fiq_count) !=
+					MAX_UNHANDLED_FIQ_COUNT)
+			return false;
+
+		debug_printf(state, "fiq_debugger: cpu %d not responding, "
+			"reverting to cpu %d\n", state->current_cpu,
+			this_cpu);
+
+		atomic_set(&state->unhandled_fiq_count, 0);
+		switch_cpu(state, this_cpu);
+		return false;
+	}
+
+	state->in_fiq = true;
+
+	while ((c = debug_getc(state)) != FIQ_DEBUGGER_NO_CHAR) {
+		count++;
+		if (!state->debug_enable) {
+			if ((c == 13) || (c == 10)) {
+				state->debug_enable = true;
+				state->debug_count = 0;
+				debug_prompt(state);
+			}
+		} else if (c == FIQ_DEBUGGER_BREAK) {
+			state->console_enable = false;
+			debug_puts(state, "fiq debugger mode\n");
+			state->debug_count = 0;
+			debug_prompt(state);
+#ifdef CONFIG_FIQ_DEBUGGER_CONSOLE
+		} else if (state->console_enable && state->tty_rbuf) {
+			fiq_debugger_ringbuf_push(state->tty_rbuf, c);
+			signal_helper = true;
+#endif
+		} else if ((c >= ' ') && (c < 127)) {
+			if (state->debug_count < (DEBUG_MAX - 1)) {
+				state->debug_buf[state->debug_count++] = c;
+				state->pdata->uart_putc(state->pdev, c);
+			}
+		} else if ((c == 8) || (c == 127)) {
+			if (state->debug_count > 0) {
+				state->debug_count--;
+				state->pdata->uart_putc(state->pdev, 8);
+				state->pdata->uart_putc(state->pdev, ' ');
+				state->pdata->uart_putc(state->pdev, 8);
+			}
+		} else if ((c == 13) || (c == 10)) {
+			if (c == '\r' || (c == '\n' && last_c != '\r')) {
+				state->pdata->uart_putc(state->pdev, '\r');
+				state->pdata->uart_putc(state->pdev, '\n');
+			}
+			if (state->debug_count) {
+				state->debug_buf[state->debug_count] = 0;
+				state->debug_count = 0;
+				signal_helper |=
+					debug_fiq_exec(state, state->debug_buf,
+						       regs, svc_sp);
+			} else {
+				debug_prompt(state);
+			}
+		}
+		last_c = c;
+	}
+	debug_uart_flush(state);
+	if (state->pdata->fiq_ack)
+		state->pdata->fiq_ack(state->pdev, state->fiq);
+
+	/* poke sleep timer if necessary */
+	if (state->debug_enable && !state->no_sleep)
+		signal_helper = true;
+
+	atomic_set(&state->unhandled_fiq_count, 0);
+	state->in_fiq = false;
+
+	return signal_helper;
+}
+
+static void debug_fiq(struct fiq_glue_handler *h, void *regs, void *svc_sp)
+{
+	struct fiq_debugger_state *state =
+		container_of(h, struct fiq_debugger_state, handler);
+	unsigned int this_cpu = THREAD_INFO(svc_sp)->cpu;
+	bool need_irq;
+
+	need_irq = debug_handle_uart_interrupt(state, this_cpu, regs, svc_sp);
+	if (need_irq)
+		debug_force_irq(state);
+}
+
+/*
+ * When not using FIQs, we only use this single interrupt as an entry point.
+ * This just effectively takes over the UART interrupt and does all the work
+ * in this context.
+ */
+static irqreturn_t debug_uart_irq(int irq, void *dev)
+{
+	struct fiq_debugger_state *state = dev;
+	bool not_done;
+
+	handle_wakeup(state);
+
+	/* handle the debugger irq in regular context */
+	not_done = debug_handle_uart_interrupt(state, smp_processor_id(),
+					      get_irq_regs(),
+					      current_thread_info());
+	if (not_done)
+		debug_handle_irq_context(state);
+
+	return IRQ_HANDLED;
+}
+
+/*
+ * If FIQs are used, not everything can happen in fiq context.
+ * FIQ handler does what it can and then signals this interrupt to finish the
+ * job in irq context.
+ */
+static irqreturn_t debug_signal_irq(int irq, void *dev)
+{
+	struct fiq_debugger_state *state = dev;
+
+	if (state->pdata->force_irq_ack)
+		state->pdata->force_irq_ack(state->pdev, state->signal_irq);
+
+	debug_handle_irq_context(state);
+
+	return IRQ_HANDLED;
+}
+
+static void debug_resume(struct fiq_glue_handler *h)
+{
+	struct fiq_debugger_state *state =
+		container_of(h, struct fiq_debugger_state, handler);
+	if (state->pdata->uart_resume)
+		state->pdata->uart_resume(state->pdev);
+}
+
+#if defined(CONFIG_FIQ_DEBUGGER_CONSOLE)
+struct tty_driver *debug_console_device(struct console *co, int *index)
+{
+	struct fiq_debugger_state *state;
+	state = container_of(co, struct fiq_debugger_state, console);
+	*index = 0;
+	return state->tty_driver;
+}
+
+static void debug_console_write(struct console *co,
+				const char *s, unsigned int count)
+{
+	struct fiq_debugger_state *state;
+
+	state = container_of(co, struct fiq_debugger_state, console);
+
+	if (!state->console_enable && !state->syslog_dumping)
+		return;
+
+	debug_uart_enable(state);
+	while (count--) {
+		if (*s == '\n')
+			state->pdata->uart_putc(state->pdev, '\r');
+		state->pdata->uart_putc(state->pdev, *s++);
+	}
+	debug_uart_flush(state);
+	debug_uart_disable(state);
+}
+
+static struct console fiq_debugger_console = {
+	.name = "ttyFIQ",
+	.device = debug_console_device,
+	.write = debug_console_write,
+	.flags = CON_PRINTBUFFER | CON_ANYTIME | CON_ENABLED,
+};
+
+int fiq_tty_open(struct tty_struct *tty, struct file *filp)
+{
+	struct fiq_debugger_state *state = tty->driver->driver_state;
+	if (state->tty_open_count++)
+		return 0;
+
+	tty->driver_data = state;
+	state->tty = tty;
+	return 0;
+}
+
+void fiq_tty_close(struct tty_struct *tty, struct file *filp)
+{
+	struct fiq_debugger_state *state = tty->driver_data;
+	if (--state->tty_open_count)
+		return;
+	state->tty = NULL;
+}
+
+int  fiq_tty_write(struct tty_struct *tty, const unsigned char *buf, int count)
+{
+	int i;
+	struct fiq_debugger_state *state = tty->driver_data;
+
+	if (!state->console_enable)
+		return count;
+
+	debug_uart_enable(state);
+	for (i = 0; i < count; i++)
+		state->pdata->uart_putc(state->pdev, *buf++);
+	debug_uart_disable(state);
+
+	return count;
+}
+
+int  fiq_tty_write_room(struct tty_struct *tty)
+{
+	return 1024;
+}
+
+static const struct tty_operations fiq_tty_driver_ops = {
+	.write = fiq_tty_write,
+	.write_room = fiq_tty_write_room,
+	.open = fiq_tty_open,
+	.close = fiq_tty_close,
+};
+
+static int fiq_debugger_tty_init(struct fiq_debugger_state *state)
+{
+	int ret = -EINVAL;
+
+	state->tty_driver = alloc_tty_driver(1);
+	if (!state->tty_driver) {
+		pr_err("Failed to allocate fiq debugger tty\n");
+		return -ENOMEM;
+	}
+
+	state->tty_driver->owner		= THIS_MODULE;
+	state->tty_driver->driver_name	= "fiq-debugger";
+	state->tty_driver->name		= "ttyFIQ";
+	state->tty_driver->type		= TTY_DRIVER_TYPE_SERIAL;
+	state->tty_driver->subtype	= SERIAL_TYPE_NORMAL;
+	state->tty_driver->init_termios	= tty_std_termios;
+	state->tty_driver->init_termios.c_cflag =
+					B115200 | CS8 | CREAD | HUPCL | CLOCAL;
+	state->tty_driver->init_termios.c_ispeed =
+		state->tty_driver->init_termios.c_ospeed = 115200;
+	state->tty_driver->flags		= TTY_DRIVER_REAL_RAW;
+	tty_set_operations(state->tty_driver, &fiq_tty_driver_ops);
+	state->tty_driver->driver_state = state;
+
+	ret = tty_register_driver(state->tty_driver);
+	if (ret) {
+		pr_err("Failed to register fiq tty: %d\n", ret);
+		goto err;
+	}
+
+	state->tty_rbuf = fiq_debugger_ringbuf_alloc(1024);
+	if (!state->tty_rbuf) {
+		pr_err("Failed to allocate fiq debugger ringbuf\n");
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	pr_info("Registered FIQ tty driver %p\n", state->tty_driver);
+	return 0;
+
+err:
+	fiq_debugger_ringbuf_free(state->tty_rbuf);
+	state->tty_rbuf = NULL;
+	put_tty_driver(state->tty_driver);
+	return ret;
+}
+#endif
+
+static int fiq_debugger_dev_suspend(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct fiq_debugger_state *state = platform_get_drvdata(pdev);
+
+	if (state->pdata->uart_dev_suspend)
+		return state->pdata->uart_dev_suspend(pdev);
+	return 0;
+}
+
+static int fiq_debugger_dev_resume(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct fiq_debugger_state *state = platform_get_drvdata(pdev);
+
+	if (state->pdata->uart_dev_resume)
+		return state->pdata->uart_dev_resume(pdev);
+	return 0;
+}
+
+static int fiq_debugger_probe(struct platform_device *pdev)
+{
+	int ret;
+	struct fiq_debugger_pdata *pdata = dev_get_platdata(&pdev->dev);
+	struct fiq_debugger_state *state;
+	int fiq;
+	int uart_irq;
+
+	if (!pdata->uart_getc || !pdata->uart_putc)
+		return -EINVAL;
+	if ((pdata->uart_enable && !pdata->uart_disable) ||
+	    (!pdata->uart_enable && pdata->uart_disable))
+		return -EINVAL;
+
+	fiq = platform_get_irq_byname(pdev, "fiq");
+	uart_irq = platform_get_irq_byname(pdev, "uart_irq");
+
+	/* uart_irq mode and fiq mode are mutually exclusive, but one of them
+	 * is required */
+	if ((uart_irq < 0 && fiq < 0) || (uart_irq >= 0 && fiq >= 0))
+		return -EINVAL;
+	if (fiq >= 0 && !pdata->fiq_enable)
+		return -EINVAL;
+
+	state = kzalloc(sizeof(*state), GFP_KERNEL);
+	setup_timer(&state->sleep_timer, sleep_timer_expired,
+		    (unsigned long)state);
+	state->pdata = pdata;
+	state->pdev = pdev;
+	state->no_sleep = initial_no_sleep;
+	state->debug_enable = initial_debug_enable;
+	state->console_enable = initial_console_enable;
+
+	state->fiq = fiq;
+	state->uart_irq = uart_irq;
+	state->signal_irq = platform_get_irq_byname(pdev, "signal");
+	state->wakeup_irq = platform_get_irq_byname(pdev, "wakeup");
+
+	platform_set_drvdata(pdev, state);
+
+	spin_lock_init(&state->sleep_timer_lock);
+
+	if (state->wakeup_irq < 0 && debug_have_fiq(state))
+		state->no_sleep = true;
+	state->ignore_next_wakeup_irq = !state->no_sleep;
+
+	wake_lock_init(&state->debugger_wake_lock,
+			WAKE_LOCK_SUSPEND, "serial-debug");
+
+	state->clk = clk_get(&pdev->dev, NULL);
+	if (IS_ERR(state->clk))
+		state->clk = NULL;
+
+	/* do not call pdata->uart_enable here since uart_init may still
+	 * need to do some initialization before uart_enable can work.
+	 * So, only try to manage the clock during init.
+	 */
+	if (state->clk)
+		clk_enable(state->clk);
+
+	if (pdata->uart_init) {
+		ret = pdata->uart_init(pdev);
+		if (ret)
+			goto err_uart_init;
+	}
+
+	debug_printf_nfiq(state, "<hit enter %sto activate fiq debugger>\n",
+				state->no_sleep ? "" : "twice ");
+
+	if (debug_have_fiq(state)) {
+		state->handler.fiq = debug_fiq;
+		state->handler.resume = debug_resume;
+		ret = fiq_glue_register_handler(&state->handler);
+		if (ret) {
+			pr_err("%s: could not install fiq handler\n", __func__);
+			goto err_register_fiq;
+		}
+
+		pdata->fiq_enable(pdev, state->fiq, 1);
+	} else {
+		ret = request_irq(state->uart_irq, debug_uart_irq,
+				  IRQF_NO_SUSPEND, "debug", state);
+		if (ret) {
+			pr_err("%s: could not install irq handler\n", __func__);
+			goto err_register_irq;
+		}
+
+		/* for irq-only mode, we want this irq to wake us up, if it
+		 * can.
+		 */
+		enable_irq_wake(state->uart_irq);
+	}
+
+	if (state->clk)
+		clk_disable(state->clk);
+
+	if (state->signal_irq >= 0) {
+		ret = request_irq(state->signal_irq, debug_signal_irq,
+			  IRQF_TRIGGER_RISING, "debug-signal", state);
+		if (ret)
+			pr_err("serial_debugger: could not install signal_irq");
+	}
+
+	if (state->wakeup_irq >= 0) {
+		ret = request_irq(state->wakeup_irq, wakeup_irq_handler,
+				  IRQF_TRIGGER_FALLING | IRQF_DISABLED,
+				  "debug-wakeup", state);
+		if (ret) {
+			pr_err("serial_debugger: "
+				"could not install wakeup irq\n");
+			state->wakeup_irq = -1;
+		} else {
+			ret = enable_irq_wake(state->wakeup_irq);
+			if (ret) {
+				pr_err("serial_debugger: "
+					"could not enable wakeup\n");
+				state->wakeup_irq_no_set_wake = true;
+			}
+		}
+	}
+	if (state->no_sleep)
+		handle_wakeup(state);
+
+#if defined(CONFIG_FIQ_DEBUGGER_CONSOLE)
+	state->console = fiq_debugger_console;
+	register_console(&state->console);
+	fiq_debugger_tty_init(state);
+#endif
+	return 0;
+
+err_register_irq:
+err_register_fiq:
+	if (pdata->uart_free)
+		pdata->uart_free(pdev);
+err_uart_init:
+	if (state->clk)
+		clk_disable(state->clk);
+	if (state->clk)
+		clk_put(state->clk);
+	wake_lock_destroy(&state->debugger_wake_lock);
+	platform_set_drvdata(pdev, NULL);
+	kfree(state);
+	return ret;
+}
+
+static const struct dev_pm_ops fiq_debugger_dev_pm_ops = {
+	.suspend	= fiq_debugger_dev_suspend,
+	.resume		= fiq_debugger_dev_resume,
+};
+
+static struct platform_driver fiq_debugger_driver = {
+	.probe	= fiq_debugger_probe,
+	.driver	= {
+		.name	= "fiq_debugger",
+		.pm	= &fiq_debugger_dev_pm_ops,
+	},
+};
+
+static int __init fiq_debugger_init(void)
+{
+	return platform_driver_register(&fiq_debugger_driver);
+}
+
+postcore_initcall(fiq_debugger_init);
diff --git a/arch/arm/common/fiq_debugger_ringbuf.h b/arch/arm/common/fiq_debugger_ringbuf.h
new file mode 100644
index 000000000000..2649b5581088
--- /dev/null
+++ b/arch/arm/common/fiq_debugger_ringbuf.h
@@ -0,0 +1,94 @@
+/*
+ * arch/arm/common/fiq_debugger_ringbuf.c
+ *
+ * simple lockless ringbuffer
+ *
+ * Copyright (C) 2010 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+
+struct fiq_debugger_ringbuf {
+	int len;
+	int head;
+	int tail;
+	u8 buf[];
+};
+
+
+static inline struct fiq_debugger_ringbuf *fiq_debugger_ringbuf_alloc(int len)
+{
+	struct fiq_debugger_ringbuf *rbuf;
+
+	rbuf = kzalloc(sizeof(*rbuf) + len, GFP_KERNEL);
+	if (rbuf == NULL)
+		return NULL;
+
+	rbuf->len = len;
+	rbuf->head = 0;
+	rbuf->tail = 0;
+	smp_mb();
+
+	return rbuf;
+}
+
+static inline void fiq_debugger_ringbuf_free(struct fiq_debugger_ringbuf *rbuf)
+{
+	kfree(rbuf);
+}
+
+static inline int fiq_debugger_ringbuf_level(struct fiq_debugger_ringbuf *rbuf)
+{
+	int level = rbuf->head - rbuf->tail;
+
+	if (level < 0)
+		level = rbuf->len + level;
+
+	return level;
+}
+
+static inline int fiq_debugger_ringbuf_room(struct fiq_debugger_ringbuf *rbuf)
+{
+	return rbuf->len - fiq_debugger_ringbuf_level(rbuf) - 1;
+}
+
+static inline u8
+fiq_debugger_ringbuf_peek(struct fiq_debugger_ringbuf *rbuf, int i)
+{
+	return rbuf->buf[(rbuf->tail + i) % rbuf->len];
+}
+
+static inline int
+fiq_debugger_ringbuf_consume(struct fiq_debugger_ringbuf *rbuf, int count)
+{
+	count = min(count, fiq_debugger_ringbuf_level(rbuf));
+
+	rbuf->tail = (rbuf->tail + count) % rbuf->len;
+	smp_mb();
+
+	return count;
+}
+
+static inline int
+fiq_debugger_ringbuf_push(struct fiq_debugger_ringbuf *rbuf, u8 datum)
+{
+	if (fiq_debugger_ringbuf_room(rbuf) == 0)
+		return 0;
+
+	rbuf->buf[rbuf->head] = datum;
+	smp_mb();
+	rbuf->head = (rbuf->head + 1) % rbuf->len;
+	smp_mb();
+
+	return 1;
+}
diff --git a/arch/arm/common/fiq_glue.S b/arch/arm/common/fiq_glue.S
new file mode 100644
index 000000000000..9e3455a09f8f
--- /dev/null
+++ b/arch/arm/common/fiq_glue.S
@@ -0,0 +1,111 @@
+/*
+ * Copyright (C) 2008 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ *
+ */
+
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+
+		.text
+
+		.global fiq_glue_end
+
+		/* fiq stack: r0-r15,cpsr,spsr of interrupted mode */
+
+ENTRY(fiq_glue)
+		/* store pc, cpsr from previous mode */
+		mrs	r12, spsr
+		sub	r11, lr, #4
+		subs	r10, #1
+		bne	nested_fiq
+
+		stmfd	sp!, {r11-r12, lr}
+
+		/* store r8-r14 from previous mode */
+		sub	sp, sp, #(7 * 4)
+		stmia	sp, {r8-r14}^
+		nop
+
+		/* store r0-r7 from previous mode */
+		stmfd	sp!, {r0-r7}
+
+		/* setup func(data,regs) arguments */
+		mov	r0, r9
+		mov	r1, sp
+		mov	r3, r8
+
+		mov	r7, sp
+
+		/* Get sp and lr from non-user modes */
+		and	r4, r12, #MODE_MASK
+		cmp	r4, #USR_MODE
+		beq	fiq_from_usr_mode
+
+		mov	r7, sp
+		orr	r4, r4, #(PSR_I_BIT | PSR_F_BIT)
+		msr	cpsr_c, r4
+		str	sp, [r7, #(4 * 13)]
+		str	lr, [r7, #(4 * 14)]
+		mrs	r5, spsr
+		str	r5, [r7, #(4 * 17)]
+
+		cmp	r4, #(SVC_MODE | PSR_I_BIT | PSR_F_BIT)
+		/* use fiq stack if we reenter this mode */
+		subne	sp, r7, #(4 * 3)
+
+fiq_from_usr_mode:
+		msr	cpsr_c, #(SVC_MODE | PSR_I_BIT | PSR_F_BIT)
+		mov	r2, sp
+		sub	sp, r7, #12
+		stmfd	sp!, {r2, ip, lr}
+		/* call func(data,regs) */
+		blx	r3
+		ldmfd	sp, {r2, ip, lr}
+		mov	sp, r2
+
+		/* restore/discard saved state */
+		cmp	r4, #USR_MODE
+		beq	fiq_from_usr_mode_exit
+
+		msr	cpsr_c, r4
+		ldr	sp, [r7, #(4 * 13)]
+		ldr	lr, [r7, #(4 * 14)]
+		msr	spsr_cxsf, r5
+
+fiq_from_usr_mode_exit:
+		msr	cpsr_c, #(FIQ_MODE | PSR_I_BIT | PSR_F_BIT)
+
+		ldmfd	sp!, {r0-r7}
+		add	sp, sp, #(7 * 4)
+		ldmfd	sp!, {r11-r12, lr}
+exit_fiq:
+		msr	spsr_cxsf, r12
+		add	r10, #1
+		movs	pc, r11
+
+nested_fiq:
+		orr	r12, r12, #(PSR_F_BIT)
+		b	exit_fiq
+
+fiq_glue_end:
+
+ENTRY(fiq_glue_setup) /* func, data, sp */
+		mrs		r3, cpsr
+		msr		cpsr_c, #(FIQ_MODE | PSR_I_BIT | PSR_F_BIT)
+		movs		r8, r0
+		mov		r9, r1
+		mov		sp, r2
+		moveq		r10, #0
+		movne		r10, #1
+		msr		cpsr_c, r3
+		bx		lr
+
diff --git a/arch/arm/common/fiq_glue_setup.c b/arch/arm/common/fiq_glue_setup.c
new file mode 100644
index 000000000000..4044c7db95c8
--- /dev/null
+++ b/arch/arm/common/fiq_glue_setup.c
@@ -0,0 +1,100 @@
+/*
+ * Copyright (C) 2010 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/percpu.h>
+#include <linux/slab.h>
+#include <asm/fiq.h>
+#include <asm/fiq_glue.h>
+
+extern unsigned char fiq_glue, fiq_glue_end;
+extern void fiq_glue_setup(void *func, void *data, void *sp);
+
+static struct fiq_handler fiq_debbuger_fiq_handler = {
+	.name = "fiq_glue",
+};
+DEFINE_PER_CPU(void *, fiq_stack);
+static struct fiq_glue_handler *current_handler;
+static DEFINE_MUTEX(fiq_glue_lock);
+
+static void fiq_glue_setup_helper(void *info)
+{
+	struct fiq_glue_handler *handler = info;
+	fiq_glue_setup(handler->fiq, handler,
+		__get_cpu_var(fiq_stack) + THREAD_START_SP);
+}
+
+int fiq_glue_register_handler(struct fiq_glue_handler *handler)
+{
+	int ret;
+	int cpu;
+
+	if (!handler || !handler->fiq)
+		return -EINVAL;
+
+	mutex_lock(&fiq_glue_lock);
+	if (fiq_stack) {
+		ret = -EBUSY;
+		goto err_busy;
+	}
+
+	for_each_possible_cpu(cpu) {
+		void *stack;
+		stack = (void *)__get_free_pages(GFP_KERNEL, THREAD_SIZE_ORDER);
+		if (WARN_ON(!stack)) {
+			ret = -ENOMEM;
+			goto err_alloc_fiq_stack;
+		}
+		per_cpu(fiq_stack, cpu) = stack;
+	}
+
+	ret = claim_fiq(&fiq_debbuger_fiq_handler);
+	if (WARN_ON(ret))
+		goto err_claim_fiq;
+
+	current_handler = handler;
+	on_each_cpu(fiq_glue_setup_helper, handler, true);
+	set_fiq_handler(&fiq_glue, &fiq_glue_end - &fiq_glue);
+
+	mutex_unlock(&fiq_glue_lock);
+	return 0;
+
+err_claim_fiq:
+err_alloc_fiq_stack:
+	for_each_possible_cpu(cpu) {
+		__free_pages(per_cpu(fiq_stack, cpu), THREAD_SIZE_ORDER);
+		per_cpu(fiq_stack, cpu) = NULL;
+	}
+err_busy:
+	mutex_unlock(&fiq_glue_lock);
+	return ret;
+}
+
+/**
+ * fiq_glue_resume - Restore fiqs after suspend or low power idle states
+ *
+ * This must be called before calling local_fiq_enable after returning from a
+ * power state where the fiq mode registers were lost. If a driver provided
+ * a resume hook when it registered the handler it will be called.
+ */
+
+void fiq_glue_resume(void)
+{
+	if (!current_handler)
+		return;
+	fiq_glue_setup(current_handler->fiq, current_handler,
+		__get_cpu_var(fiq_stack) + THREAD_START_SP);
+	if (current_handler->resume)
+		current_handler->resume(current_handler);
+}
+