Merge git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-kgdb

* git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-kgdb:
  kgdb: always use icache flush for sw breakpoints
  kgdb: fix SMP NMI kgdb_handle_exception exit race
  kgdb: documentation fixes
  kgdb: allow static kgdbts boot configuration
  kgdb: add documentation
  kgdb: Kconfig fix
  kgdb: add kgdb internal test suite
  kgdb: fix several kgdb regressions
  kgdb: kgdboc pl011 I/O module
  kgdb: fix optional arch functions and probe_kernel_*
  kgdb: add x86 HW breakpoints
  kgdb: print breakpoint removed on exception
  kgdb: clocksource watchdog
  kgdb: fix NMI hangs
  kgdb: fix kgdboc dynamic module configuration
  kgdb: document parameters
  x86: kgdb support
  consoles: polling support, kgdboc
  kgdb: core
  uaccess: add probe_kernel_write()

9 files changed, 1468 insertions, 4 deletions

diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index 613ec816ce60..4d3c7018f0c3 100644
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -1155,6 +1155,48 @@ static struct tty_driver *get_tty_driver(dev_t device, int *index)
         return NULL;
 }
 
+#ifdef CONFIG_CONSOLE_POLL
+
+/**
+ *      tty_find_polling_driver -       find device of a polled tty
+ *      @name: name string to match
+ *      @line: pointer to resulting tty line nr
+ *
+ *      This routine returns a tty driver structure, given a name
+ *      and the condition that the tty driver is capable of polled
+ *      operation.
+ */
+struct tty_driver *tty_find_polling_driver(char *name, int *line)
+{
+        struct tty_driver *p, *res = NULL;
+        int tty_line = 0;
+        char *str;
+
+        mutex_lock(&tty_mutex);
+        /* Search through the tty devices to look for a match */
+        list_for_each_entry(p, &tty_drivers, tty_drivers) {
+                str = name + strlen(p->name);
+                tty_line = simple_strtoul(str, &str, 10);
+                if (*str == ',')
+                        str++;
+                if (*str == '\0')
+                        str = 0;
+
+                if (tty_line >= 0 && tty_line <= p->num && p->poll_init &&
+                                !p->poll_init(p, tty_line, str)) {
+
+                        res = p;
+                        *line = tty_line;
+                        break;
+                }
+        }
+        mutex_unlock(&tty_mutex);
+
+        return res;
+}
+EXPORT_SYMBOL_GPL(tty_find_polling_driver);
+#endif
+
 /**
  *      tty_check_change        -       check for POSIX terminal changes
  *      @tty: tty to check
@@ -3850,6 +3892,11 @@ void tty_set_operations(struct tty_driver *driver,
         driver->write_proc = op->write_proc;
         driver->tiocmget = op->tiocmget;
         driver->tiocmset = op->tiocmset;
+#ifdef CONFIG_CONSOLE_POLL
+        driver->poll_init = op->poll_init;
+        driver->poll_get_char = op->poll_get_char;
+        driver->poll_put_char = op->poll_put_char;
+#endif
 }
 
 
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index 3b12f5da8562..bbc69fdd1b9d 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -22,3 +22,4 @@ obj-$(CONFIG_FUJITSU_LAPTOP)	+= fujitsu-laptop.o
 obj-$(CONFIG_EEPROM_93CX6)      += eeprom_93cx6.o
 obj-$(CONFIG_INTEL_MENLOW)      += intel_menlow.o
 obj-$(CONFIG_ENCLOSURE_SERVICES) += enclosure.o
+obj-$(CONFIG_KGDB_TESTS)        += kgdbts.o
diff --git a/drivers/misc/kgdbts.c b/drivers/misc/kgdbts.c
new file mode 100644
index 000000000000..6d6286c4eeac
--- /dev/null
+++ b/drivers/misc/kgdbts.c
@@ -0,0 +1,1090 @@
+/*
+ * kgdbts is a test suite for kgdb for the sole purpose of validating
+ * that key pieces of the kgdb internals are working properly such as
+ * HW/SW breakpoints, single stepping, and NMI.
+ *
+ * Created by: Jason Wessel <jason.wessel@windriver.com>
+ *
+ * Copyright (c) 2008 Wind River Systems, Inc.
+ *
+ * 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
+ */
+/* Information about the kgdb test suite.
+ * -------------------------------------
+ *
+ * The kgdb test suite is designed as a KGDB I/O module which
+ * simulates the communications that a debugger would have with kgdb.
+ * The tests are broken up in to a line by line and referenced here as
+ * a "get" which is kgdb requesting input and "put" which is kgdb
+ * sending a response.
+ *
+ * The kgdb suite can be invoked from the kernel command line
+ * arguments system or executed dynamically at run time.  The test
+ * suite uses the variable "kgdbts" to obtain the information about
+ * which tests to run and to configure the verbosity level.  The
+ * following are the various characters you can use with the kgdbts=
+ * line:
+ *
+ * When using the "kgdbts=" you only choose one of the following core
+ * test types:
+ * A = Run all the core tests silently
+ * V1 = Run all the core tests with minimal output
+ * V2 = Run all the core tests in debug mode
+ *
+ * You can also specify optional tests:
+ * N## = Go to sleep with interrupts of for ## seconds
+ *       to test the HW NMI watchdog
+ * F## = Break at do_fork for ## iterations
+ * S## = Break at sys_open for ## iterations
+ *
+ * NOTE: that the do_fork and sys_open tests are mutually exclusive.
+ *
+ * To invoke the kgdb test suite from boot you use a kernel start
+ * argument as follows:
+ *      kgdbts=V1 kgdbwait
+ * Or if you wanted to perform the NMI test for 6 seconds and do_fork
+ * test for 100 forks, you could use:
+ *      kgdbts=V1N6F100 kgdbwait
+ *
+ * The test suite can also be invoked at run time with:
+ *      echo kgdbts=V1N6F100 > /sys/module/kgdbts/parameters/kgdbts
+ * Or as another example:
+ *      echo kgdbts=V2 > /sys/module/kgdbts/parameters/kgdbts
+ *
+ * When developing a new kgdb arch specific implementation or
+ * using these tests for the purpose of regression testing,
+ * several invocations are required.
+ *
+ * 1) Boot with the test suite enabled by using the kernel arguments
+ *       "kgdbts=V1F100 kgdbwait"
+ *    ## If kgdb arch specific implementation has NMI use
+ *       "kgdbts=V1N6F100
+ *
+ * 2) After the system boot run the basic test.
+ * echo kgdbts=V1 > /sys/module/kgdbts/parameters/kgdbts
+ *
+ * 3) Run the concurrency tests.  It is best to use n+1
+ *    while loops where n is the number of cpus you have
+ *    in your system.  The example below uses only two
+ *    loops.
+ *
+ * ## This tests break points on sys_open
+ * while [ 1 ] ; do find / > /dev/null 2>&1 ; done &
+ * while [ 1 ] ; do find / > /dev/null 2>&1 ; done &
+ * echo kgdbts=V1S10000 > /sys/module/kgdbts/parameters/kgdbts
+ * fg # and hit control-c
+ * fg # and hit control-c
+ * ## This tests break points on do_fork
+ * while [ 1 ] ; do date > /dev/null ; done &
+ * while [ 1 ] ; do date > /dev/null ; done &
+ * echo kgdbts=V1F1000 > /sys/module/kgdbts/parameters/kgdbts
+ * fg # and hit control-c
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/kgdb.h>
+#include <linux/ctype.h>
+#include <linux/uaccess.h>
+#include <linux/syscalls.h>
+#include <linux/nmi.h>
+#include <linux/delay.h>
+#include <linux/kthread.h>
+#include <linux/delay.h>
+
+#define v1printk(a...) do { \
+        if (verbose) \
+                printk(KERN_INFO a); \
+        } while (0)
+#define v2printk(a...) do { \
+        if (verbose > 1) \
+                printk(KERN_INFO a); \
+                touch_nmi_watchdog();   \
+        } while (0)
+#define eprintk(a...) do { \
+                printk(KERN_ERR a); \
+                WARN_ON(1); \
+        } while (0)
+#define MAX_CONFIG_LEN          40
+
+static const char hexchars[] = "0123456789abcdef";
+static struct kgdb_io kgdbts_io_ops;
+static char get_buf[BUFMAX];
+static int get_buf_cnt;
+static char put_buf[BUFMAX];
+static int put_buf_cnt;
+static char scratch_buf[BUFMAX];
+static int verbose;
+static int repeat_test;
+static int test_complete;
+static int send_ack;
+static int final_ack;
+static int hw_break_val;
+static int hw_break_val2;
+#if defined(CONFIG_ARM) || defined(CONFIG_MIPS)
+static int arch_needs_sstep_emulation = 1;
+#else
+static int arch_needs_sstep_emulation;
+#endif
+static unsigned long sstep_addr;
+static int sstep_state;
+
+/* Storage for the registers, in GDB format. */
+static unsigned long kgdbts_gdb_regs[(NUMREGBYTES +
+                                        sizeof(unsigned long) - 1) /
+                                        sizeof(unsigned long)];
+static struct pt_regs kgdbts_regs;
+
+/* -1 = init not run yet, 0 = unconfigured, 1 = configured. */
+static int configured           = -1;
+
+#ifdef CONFIG_KGDB_TESTS_BOOT_STRING
+static char config[MAX_CONFIG_LEN] = CONFIG_KGDB_TESTS_BOOT_STRING;
+#else
+static char config[MAX_CONFIG_LEN];
+#endif
+static struct kparam_string kps = {
+        .string                 = config,
+        .maxlen                 = MAX_CONFIG_LEN,
+};
+
+static void fill_get_buf(char *buf);
+
+struct test_struct {
+        char *get;
+        char *put;
+        void (*get_handler)(char *);
+        int (*put_handler)(char *, char *);
+};
+
+struct test_state {
+        char *name;
+        struct test_struct *tst;
+        int idx;
+        int (*run_test) (int, int);
+        int (*validate_put) (char *);
+};
+
+static struct test_state ts;
+
+static int kgdbts_unreg_thread(void *ptr)
+{
+        /* Wait until the tests are complete and then ungresiter the I/O
+         * driver.
+         */
+        while (!final_ack)
+                msleep_interruptible(1500);
+
+        if (configured)
+                kgdb_unregister_io_module(&kgdbts_io_ops);
+        configured = 0;
+
+        return 0;
+}
+
+/* This is noinline such that it can be used for a single location to
+ * place a breakpoint
+ */
+static noinline void kgdbts_break_test(void)
+{
+        v2printk("kgdbts: breakpoint complete\n");
+}
+
+/* Lookup symbol info in the kernel */
+static unsigned long lookup_addr(char *arg)
+{
+        unsigned long addr = 0;
+
+        if (!strcmp(arg, "kgdbts_break_test"))
+                addr = (unsigned long)kgdbts_break_test;
+        else if (!strcmp(arg, "sys_open"))
+                addr = (unsigned long)sys_open;
+        else if (!strcmp(arg, "do_fork"))
+                addr = (unsigned long)do_fork;
+        else if (!strcmp(arg, "hw_break_val"))
+                addr = (unsigned long)&hw_break_val;
+        return addr;
+}
+
+static void break_helper(char *bp_type, char *arg, unsigned long vaddr)
+{
+        unsigned long addr;
+
+        if (arg)
+                addr = lookup_addr(arg);
+        else
+                addr = vaddr;
+
+        sprintf(scratch_buf, "%s,%lx,%i", bp_type, addr,
+                BREAK_INSTR_SIZE);
+        fill_get_buf(scratch_buf);
+}
+
+static void sw_break(char *arg)
+{
+        break_helper("Z0", arg, 0);
+}
+
+static void sw_rem_break(char *arg)
+{
+        break_helper("z0", arg, 0);
+}
+
+static void hw_break(char *arg)
+{
+        break_helper("Z1", arg, 0);
+}
+
+static void hw_rem_break(char *arg)
+{
+        break_helper("z1", arg, 0);
+}
+
+static void hw_write_break(char *arg)
+{
+        break_helper("Z2", arg, 0);
+}
+
+static void hw_rem_write_break(char *arg)
+{
+        break_helper("z2", arg, 0);
+}
+
+static void hw_access_break(char *arg)
+{
+        break_helper("Z4", arg, 0);
+}
+
+static void hw_rem_access_break(char *arg)
+{
+        break_helper("z4", arg, 0);
+}
+
+static void hw_break_val_access(void)
+{
+        hw_break_val2 = hw_break_val;
+}
+
+static void hw_break_val_write(void)
+{
+        hw_break_val++;
+}
+
+static int check_and_rewind_pc(char *put_str, char *arg)
+{
+        unsigned long addr = lookup_addr(arg);
+        int offset = 0;
+
+        kgdb_hex2mem(&put_str[1], (char *)kgdbts_gdb_regs,
+                 NUMREGBYTES);
+        gdb_regs_to_pt_regs(kgdbts_gdb_regs, &kgdbts_regs);
+        v2printk("Stopped at IP: %lx\n", instruction_pointer(&kgdbts_regs));
+#ifdef CONFIG_X86
+        /* On x86 a breakpoint stop requires it to be decremented */
+        if (addr + 1 == kgdbts_regs.ip)
+                offset = -1;
+#endif
+        if (strcmp(arg, "silent") &&
+                instruction_pointer(&kgdbts_regs) + offset != addr) {
+                eprintk("kgdbts: BP mismatch %lx expected %lx\n",
+                           instruction_pointer(&kgdbts_regs) + offset, addr);
+                return 1;
+        }
+#ifdef CONFIG_X86
+        /* On x86 adjust the instruction pointer if needed */
+        kgdbts_regs.ip += offset;
+#endif
+        return 0;
+}
+
+static int check_single_step(char *put_str, char *arg)
+{
+        unsigned long addr = lookup_addr(arg);
+        /*
+         * From an arch indepent point of view the instruction pointer
+         * should be on a different instruction
+         */
+        kgdb_hex2mem(&put_str[1], (char *)kgdbts_gdb_regs,
+                 NUMREGBYTES);
+        gdb_regs_to_pt_regs(kgdbts_gdb_regs, &kgdbts_regs);
+        v2printk("Singlestep stopped at IP: %lx\n",
+                   instruction_pointer(&kgdbts_regs));
+        if (instruction_pointer(&kgdbts_regs) == addr) {
+                eprintk("kgdbts: SingleStep failed at %lx\n",
+                           instruction_pointer(&kgdbts_regs));
+                return 1;
+        }
+
+        return 0;
+}
+
+static void write_regs(char *arg)
+{
+        memset(scratch_buf, 0, sizeof(scratch_buf));
+        scratch_buf[0] = 'G';
+        pt_regs_to_gdb_regs(kgdbts_gdb_regs, &kgdbts_regs);
+        kgdb_mem2hex((char *)kgdbts_gdb_regs, &scratch_buf[1], NUMREGBYTES);
+        fill_get_buf(scratch_buf);
+}
+
+static void skip_back_repeat_test(char *arg)
+{
+        int go_back = simple_strtol(arg, NULL, 10);
+
+        repeat_test--;
+        if (repeat_test <= 0)
+                ts.idx++;
+        else
+                ts.idx -= go_back;
+        fill_get_buf(ts.tst[ts.idx].get);
+}
+
+static int got_break(char *put_str, char *arg)
+{
+        test_complete = 1;
+        if (!strncmp(put_str+1, arg, 2)) {
+                if (!strncmp(arg, "T0", 2))
+                        test_complete = 2;
+                return 0;
+        }
+        return 1;
+}
+
+static void emul_sstep_get(char *arg)
+{
+        if (!arch_needs_sstep_emulation) {
+                fill_get_buf(arg);
+                return;
+        }
+        switch (sstep_state) {
+        case 0:
+                v2printk("Emulate single step\n");
+                /* Start by looking at the current PC */
+                fill_get_buf("g");
+                break;
+        case 1:
+                /* set breakpoint */
+                break_helper("Z0", 0, sstep_addr);
+                break;
+        case 2:
+                /* Continue */
+                fill_get_buf("c");
+                break;
+        case 3:
+                /* Clear breakpoint */
+                break_helper("z0", 0, sstep_addr);
+                break;
+        default:
+                eprintk("kgdbts: ERROR failed sstep get emulation\n");
+        }
+        sstep_state++;
+}
+
+static int emul_sstep_put(char *put_str, char *arg)
+{
+        if (!arch_needs_sstep_emulation) {
+                if (!strncmp(put_str+1, arg, 2))
+                        return 0;
+                return 1;
+        }
+        switch (sstep_state) {
+        case 1:
+                /* validate the "g" packet to get the IP */
+                kgdb_hex2mem(&put_str[1], (char *)kgdbts_gdb_regs,
+                         NUMREGBYTES);
+                gdb_regs_to_pt_regs(kgdbts_gdb_regs, &kgdbts_regs);
+                v2printk("Stopped at IP: %lx\n",
+                         instruction_pointer(&kgdbts_regs));
+                /* Want to stop at IP + break instruction size by default */
+                sstep_addr = instruction_pointer(&kgdbts_regs) +
+                        BREAK_INSTR_SIZE;
+                break;
+        case 2:
+                if (strncmp(put_str, "$OK", 3)) {
+                        eprintk("kgdbts: failed sstep break set\n");
+                        return 1;
+                }
+                break;
+        case 3:
+                if (strncmp(put_str, "$T0", 3)) {
+                        eprintk("kgdbts: failed continue sstep\n");
+                        return 1;
+                }
+                break;
+        case 4:
+                if (strncmp(put_str, "$OK", 3)) {
+                        eprintk("kgdbts: failed sstep break unset\n");
+                        return 1;
+                }
+                /* Single step is complete so continue on! */
+                sstep_state = 0;
+                return 0;
+        default:
+                eprintk("kgdbts: ERROR failed sstep put emulation\n");
+        }
+
+        /* Continue on the same test line until emulation is complete */
+        ts.idx--;
+        return 0;
+}
+
+static int final_ack_set(char *put_str, char *arg)
+{
+        if (strncmp(put_str+1, arg, 2))
+                return 1;
+        final_ack = 1;
+        return 0;
+}
+/*
+ * Test to plant a breakpoint and detach, which should clear out the
+ * breakpoint and restore the original instruction.
+ */
+static struct test_struct plant_and_detach_test[] = {
+        { "?", "S0*" }, /* Clear break points */
+        { "kgdbts_break_test", "OK", sw_break, }, /* set sw breakpoint */
+        { "D", "OK" }, /* Detach */
+        { "", "" },
+};
+
+/*
+ * Simple test to write in a software breakpoint, check for the
+ * correct stop location and detach.
+ */
+static struct test_struct sw_breakpoint_test[] = {
+        { "?", "S0*" }, /* Clear break points */
+        { "kgdbts_break_test", "OK", sw_break, }, /* set sw breakpoint */
+        { "c", "T0*", }, /* Continue */
+        { "g", "kgdbts_break_test", 0, check_and_rewind_pc },
+        { "write", "OK", write_regs },
+        { "kgdbts_break_test", "OK", sw_rem_break }, /*remove breakpoint */
+        { "D", "OK" }, /* Detach */
+        { "D", "OK", 0,  got_break }, /* If the test worked we made it here */
+        { "", "" },
+};
+
+/*
+ * Test a known bad memory read location to test the fault handler and
+ * read bytes 1-8 at the bad address
+ */
+static struct test_struct bad_read_test[] = {
+        { "?", "S0*" }, /* Clear break points */
+        { "m0,1", "E*" }, /* read 1 byte at address 1 */
+        { "m0,2", "E*" }, /* read 1 byte at address 2 */
+        { "m0,3", "E*" }, /* read 1 byte at address 3 */
+        { "m0,4", "E*" }, /* read 1 byte at address 4 */
+        { "m0,5", "E*" }, /* read 1 byte at address 5 */
+        { "m0,6", "E*" }, /* read 1 byte at address 6 */
+        { "m0,7", "E*" }, /* read 1 byte at address 7 */
+        { "m0,8", "E*" }, /* read 1 byte at address 8 */
+        { "D", "OK" }, /* Detach which removes all breakpoints and continues */
+        { "", "" },
+};
+
+/*
+ * Test for hitting a breakpoint, remove it, single step, plant it
+ * again and detach.
+ */
+static struct test_struct singlestep_break_test[] = {
+        { "?", "S0*" }, /* Clear break points */
+        { "kgdbts_break_test", "OK", sw_break, }, /* set sw breakpoint */
+        { "c", "T0*", }, /* Continue */
+        { "g", "kgdbts_break_test", 0, check_and_rewind_pc },
+        { "write", "OK", write_regs }, /* Write registers */
+        { "kgdbts_break_test", "OK", sw_rem_break }, /*remove breakpoint */
+        { "s", "T0*", emul_sstep_get, emul_sstep_put }, /* Single step */
+        { "g", "kgdbts_break_test", 0, check_single_step },
+        { "kgdbts_break_test", "OK", sw_break, }, /* set sw breakpoint */
+        { "c", "T0*", }, /* Continue */
+        { "g", "kgdbts_break_test", 0, check_and_rewind_pc },
+        { "write", "OK", write_regs }, /* Write registers */
+        { "D", "OK" }, /* Remove all breakpoints and continues */
+        { "", "" },
+};
+
+/*
+ * Test for hitting a breakpoint at do_fork for what ever the number
+ * of iterations required by the variable repeat_test.
+ */
+static struct test_struct do_fork_test[] = {
+        { "?", "S0*" }, /* Clear break points */
+        { "do_fork", "OK", sw_break, }, /* set sw breakpoint */
+        { "c", "T0*", }, /* Continue */
+        { "g", "do_fork", 0, check_and_rewind_pc }, /* check location */
+        { "write", "OK", write_regs }, /* Write registers */
+        { "do_fork", "OK", sw_rem_break }, /*remove breakpoint */
+        { "s", "T0*", emul_sstep_get, emul_sstep_put }, /* Single step */
+        { "g", "do_fork", 0, check_single_step },
+        { "do_fork", "OK", sw_break, }, /* set sw breakpoint */
+        { "7", "T0*", skip_back_repeat_test }, /* Loop based on repeat_test */
+        { "D", "OK", 0, final_ack_set }, /* detach and unregister I/O */
+        { "", "" },
+};
+
+/* Test for hitting a breakpoint at sys_open for what ever the number
+ * of iterations required by the variable repeat_test.
+ */
+static struct test_struct sys_open_test[] = {
+        { "?", "S0*" }, /* Clear break points */
+        { "sys_open", "OK", sw_break, }, /* set sw breakpoint */
+        { "c", "T0*", }, /* Continue */
+        { "g", "sys_open", 0, check_and_rewind_pc }, /* check location */
+        { "write", "OK", write_regs }, /* Write registers */
+        { "sys_open", "OK", sw_rem_break }, /*remove breakpoint */
+        { "s", "T0*", emul_sstep_get, emul_sstep_put }, /* Single step */
+        { "g", "sys_open", 0, check_single_step },
+        { "sys_open", "OK", sw_break, }, /* set sw breakpoint */
+        { "7", "T0*", skip_back_repeat_test }, /* Loop based on repeat_test */
+        { "D", "OK", 0, final_ack_set }, /* detach and unregister I/O */
+        { "", "" },
+};
+
+/*
+ * Test for hitting a simple hw breakpoint
+ */
+static struct test_struct hw_breakpoint_test[] = {
+        { "?", "S0*" }, /* Clear break points */
+        { "kgdbts_break_test", "OK", hw_break, }, /* set hw breakpoint */
+        { "c", "T0*", }, /* Continue */
+        { "g", "kgdbts_break_test", 0, check_and_rewind_pc },
+        { "write", "OK", write_regs },
+        { "kgdbts_break_test", "OK", hw_rem_break }, /*remove breakpoint */
+        { "D", "OK" }, /* Detach */
+        { "D", "OK", 0,  got_break }, /* If the test worked we made it here */
+        { "", "" },
+};
+
+/*
+ * Test for hitting a hw write breakpoint
+ */
+static struct test_struct hw_write_break_test[] = {
+        { "?", "S0*" }, /* Clear break points */
+        { "hw_break_val", "OK", hw_write_break, }, /* set hw breakpoint */
+        { "c", "T0*", 0, got_break }, /* Continue */
+        { "g", "silent", 0, check_and_rewind_pc },
+        { "write", "OK", write_regs },
+        { "hw_break_val", "OK", hw_rem_write_break }, /*remove breakpoint */
+        { "D", "OK" }, /* Detach */
+        { "D", "OK", 0,  got_break }, /* If the test worked we made it here */
+        { "", "" },
+};
+
+/*
+ * Test for hitting a hw access breakpoint
+ */
+static struct test_struct hw_access_break_test[] = {
+        { "?", "S0*" }, /* Clear break points */
+        { "hw_break_val", "OK", hw_access_break, }, /* set hw breakpoint */
+        { "c", "T0*", 0, got_break }, /* Continue */
+        { "g", "silent", 0, check_and_rewind_pc },
+        { "write", "OK", write_regs },
+        { "hw_break_val", "OK", hw_rem_access_break }, /*remove breakpoint */
+        { "D", "OK" }, /* Detach */
+        { "D", "OK", 0,  got_break }, /* If the test worked we made it here */
+        { "", "" },
+};
+
+/*
+ * Test for hitting a hw access breakpoint
+ */
+static struct test_struct nmi_sleep_test[] = {
+        { "?", "S0*" }, /* Clear break points */
+        { "c", "T0*", 0, got_break }, /* Continue */
+        { "D", "OK" }, /* Detach */
+        { "D", "OK", 0,  got_break }, /* If the test worked we made it here */
+        { "", "" },
+};
+
+static void fill_get_buf(char *buf)
+{
+        unsigned char checksum = 0;
+        int count = 0;
+        char ch;
+
+        strcpy(get_buf, "$");
+        strcat(get_buf, buf);
+        while ((ch = buf[count])) {
+                checksum += ch;
+                count++;
+        }
+        strcat(get_buf, "#");
+        get_buf[count + 2] = hexchars[checksum >> 4];
+        get_buf[count + 3] = hexchars[checksum & 0xf];
+        get_buf[count + 4] = '\0';
+        v2printk("get%i: %s\n", ts.idx, get_buf);
+}
+
+static int validate_simple_test(char *put_str)
+{
+        char *chk_str;
+
+        if (ts.tst[ts.idx].put_handler)
+                return ts.tst[ts.idx].put_handler(put_str,
+                        ts.tst[ts.idx].put);
+
+        chk_str = ts.tst[ts.idx].put;
+        if (*put_str == '$')
+                put_str++;
+
+        while (*chk_str != '\0' && *put_str != '\0') {
+                /* If someone does a * to match the rest of the string, allow
+                 * it, or stop if the recieved string is complete.
+                 */
+                if (*put_str == '#' || *chk_str == '*')
+                        return 0;
+                if (*put_str != *chk_str)
+                        return 1;
+
+                chk_str++;
+                put_str++;
+        }
+        if (*chk_str == '\0' && (*put_str == '\0' || *put_str == '#'))
+                return 0;
+
+        return 1;
+}
+
+static int run_simple_test(int is_get_char, int chr)
+{
+        int ret = 0;
+        if (is_get_char) {
+                /* Send an ACK on the get if a prior put completed and set the
+                 * send ack variable
+                 */
+                if (send_ack) {
+                        send_ack = 0;
+                        return '+';
+                }
+                /* On the first get char, fill the transmit buffer and then
+                 * take from the get_string.
+                 */
+                if (get_buf_cnt == 0) {
+                        if (ts.tst[ts.idx].get_handler)
+                                ts.tst[ts.idx].get_handler(ts.tst[ts.idx].get);
+                        else
+                                fill_get_buf(ts.tst[ts.idx].get);
+                }
+
+                if (get_buf[get_buf_cnt] == '\0') {
+                        eprintk("kgdbts: ERROR GET: EOB on '%s' at %i\n",
+                           ts.name, ts.idx);
+                        get_buf_cnt = 0;
+                        fill_get_buf("D");
+                }
+                ret = get_buf[get_buf_cnt];
+                get_buf_cnt++;
+                return ret;
+        }
+
+        /* This callback is a put char which is when kgdb sends data to
+         * this I/O module.
+         */
+        if (ts.tst[ts.idx].get[0] == '\0' &&
+                ts.tst[ts.idx].put[0] == '\0') {
+                eprintk("kgdbts: ERROR: beyond end of test on"
+                           " '%s' line %i\n", ts.name, ts.idx);
+                return 0;
+        }
+
+        if (put_buf_cnt >= BUFMAX) {
+                eprintk("kgdbts: ERROR: put buffer overflow on"
+                           " '%s' line %i\n", ts.name, ts.idx);
+                put_buf_cnt = 0;
+                return 0;
+        }
+        /* Ignore everything until the first valid packet start '$' */
+        if (put_buf_cnt == 0 && chr != '$')
+                return 0;
+
+        put_buf[put_buf_cnt] = chr;
+        put_buf_cnt++;
+
+        /* End of packet == #XX so look for the '#' */
+        if (put_buf_cnt > 3 && put_buf[put_buf_cnt - 3] == '#') {
+                put_buf[put_buf_cnt] = '\0';
+                v2printk("put%i: %s\n", ts.idx, put_buf);
+                /* Trigger check here */
+                if (ts.validate_put && ts.validate_put(put_buf)) {
+                        eprintk("kgdbts: ERROR PUT: end of test "
+                           "buffer on '%s' line %i expected %s got %s\n",
+                           ts.name, ts.idx, ts.tst[ts.idx].put, put_buf);
+                }
+                ts.idx++;
+                put_buf_cnt = 0;
+                get_buf_cnt = 0;
+                send_ack = 1;
+        }
+        return 0;
+}
+
+static void init_simple_test(void)
+{
+        memset(&ts, 0, sizeof(ts));
+        ts.run_test = run_simple_test;
+        ts.validate_put = validate_simple_test;
+}
+
+static void run_plant_and_detach_test(int is_early)
+{
+        char before[BREAK_INSTR_SIZE];
+        char after[BREAK_INSTR_SIZE];
+
+        probe_kernel_read(before, (char *)kgdbts_break_test,
+          BREAK_INSTR_SIZE);
+        init_simple_test();
+        ts.tst = plant_and_detach_test;
+        ts.name = "plant_and_detach_test";
+        /* Activate test with initial breakpoint */
+        if (!is_early)
+                kgdb_breakpoint();
+        probe_kernel_read(after, (char *)kgdbts_break_test,
+          BREAK_INSTR_SIZE);
+        if (memcmp(before, after, BREAK_INSTR_SIZE)) {
+                printk(KERN_CRIT "kgdbts: ERROR kgdb corrupted memory\n");
+                panic("kgdb memory corruption");
+        }
+
+        /* complete the detach test */
+        if (!is_early)
+                kgdbts_break_test();
+}
+
+static void run_breakpoint_test(int is_hw_breakpoint)
+{
+        test_complete = 0;
+        init_simple_test();
+        if (is_hw_breakpoint) {
+                ts.tst = hw_breakpoint_test;
+                ts.name = "hw_breakpoint_test";
+        } else {
+                ts.tst = sw_breakpoint_test;
+                ts.name = "sw_breakpoint_test";
+        }
+        /* Activate test with initial breakpoint */
+        kgdb_breakpoint();
+        /* run code with the break point in it */
+        kgdbts_break_test();
+        kgdb_breakpoint();
+
+        if (test_complete)
+                return;
+
+        eprintk("kgdbts: ERROR %s test failed\n", ts.name);
+}
+
+static void run_hw_break_test(int is_write_test)
+{
+        test_complete = 0;
+        init_simple_test();
+        if (is_write_test) {
+                ts.tst = hw_write_break_test;
+                ts.name = "hw_write_break_test";
+        } else {
+                ts.tst = hw_access_break_test;
+                ts.name = "hw_access_break_test";
+        }
+        /* Activate test with initial breakpoint */
+        kgdb_breakpoint();
+        hw_break_val_access();
+        if (is_write_test) {
+                if (test_complete == 2)
+                        eprintk("kgdbts: ERROR %s broke on access\n",
+                                ts.name);
+                hw_break_val_write();
+        }
+        kgdb_breakpoint();
+
+        if (test_complete == 1)
+                return;
+
+        eprintk("kgdbts: ERROR %s test failed\n", ts.name);
+}
+
+static void run_nmi_sleep_test(int nmi_sleep)
+{
+        unsigned long flags;
+
+        init_simple_test();
+        ts.tst = nmi_sleep_test;
+        ts.name = "nmi_sleep_test";
+        /* Activate test with initial breakpoint */
+        kgdb_breakpoint();
+        local_irq_save(flags);
+        mdelay(nmi_sleep*1000);
+        touch_nmi_watchdog();
+        local_irq_restore(flags);
+        if (test_complete != 2)
+                eprintk("kgdbts: ERROR nmi_test did not hit nmi\n");
+        kgdb_breakpoint();
+        if (test_complete == 1)
+                return;
+
+        eprintk("kgdbts: ERROR %s test failed\n", ts.name);
+}
+
+static void run_bad_read_test(void)
+{
+        init_simple_test();
+        ts.tst = bad_read_test;
+        ts.name = "bad_read_test";
+        /* Activate test with initial breakpoint */
+        kgdb_breakpoint();
+}
+
+static void run_do_fork_test(void)
+{
+        init_simple_test();
+        ts.tst = do_fork_test;
+        ts.name = "do_fork_test";
+        /* Activate test with initial breakpoint */
+        kgdb_breakpoint();
+}
+
+static void run_sys_open_test(void)
+{
+        init_simple_test();
+        ts.tst = sys_open_test;
+        ts.name = "sys_open_test";
+        /* Activate test with initial breakpoint */
+        kgdb_breakpoint();
+}
+
+static void run_singlestep_break_test(void)
+{
+        init_simple_test();
+        ts.tst = singlestep_break_test;
+        ts.name = "singlestep_breakpoint_test";
+        /* Activate test with initial breakpoint */
+        kgdb_breakpoint();
+        kgdbts_break_test();
+        kgdbts_break_test();
+}
+
+static void kgdbts_run_tests(void)
+{
+        char *ptr;
+        int fork_test = 0;
+        int sys_open_test = 0;
+        int nmi_sleep = 0;
+
+        ptr = strstr(config, "F");
+        if (ptr)
+                fork_test = simple_strtol(ptr+1, NULL, 10);
+        ptr = strstr(config, "S");
+        if (ptr)
+                sys_open_test = simple_strtol(ptr+1, NULL, 10);
+        ptr = strstr(config, "N");
+        if (ptr)
+                nmi_sleep = simple_strtol(ptr+1, NULL, 10);
+
+        /* required internal KGDB tests */
+        v1printk("kgdbts:RUN plant and detach test\n");
+        run_plant_and_detach_test(0);
+        v1printk("kgdbts:RUN sw breakpoint test\n");
+        run_breakpoint_test(0);
+        v1printk("kgdbts:RUN bad memory access test\n");
+        run_bad_read_test();
+        v1printk("kgdbts:RUN singlestep breakpoint test\n");
+        run_singlestep_break_test();
+
+        /* ===Optional tests=== */
+
+        /* All HW break point tests */
+        if (arch_kgdb_ops.flags & KGDB_HW_BREAKPOINT) {
+                v1printk("kgdbts:RUN hw breakpoint test\n");
+                run_breakpoint_test(1);
+                v1printk("kgdbts:RUN hw write breakpoint test\n");
+                run_hw_break_test(1);
+                v1printk("kgdbts:RUN access write breakpoint test\n");
+                run_hw_break_test(0);
+        }
+
+        if (nmi_sleep) {
+                v1printk("kgdbts:RUN NMI sleep %i seconds test\n", nmi_sleep);
+                run_nmi_sleep_test(nmi_sleep);
+        }
+
+        /* If the do_fork test is run it will be the last test that is
+         * executed because a kernel thread will be spawned at the very
+         * end to unregister the debug hooks.
+         */
+        if (fork_test) {
+                repeat_test = fork_test;
+                printk(KERN_INFO "kgdbts:RUN do_fork for %i breakpoints\n",
+                        repeat_test);
+                kthread_run(kgdbts_unreg_thread, 0, "kgdbts_unreg");
+                run_do_fork_test();
+                return;
+        }
+
+        /* If the sys_open test is run it will be the last test that is
+         * executed because a kernel thread will be spawned at the very
+         * end to unregister the debug hooks.
+         */
+        if (sys_open_test) {
+                repeat_test = sys_open_test;
+                printk(KERN_INFO "kgdbts:RUN sys_open for %i breakpoints\n",
+                        repeat_test);
+                kthread_run(kgdbts_unreg_thread, 0, "kgdbts_unreg");
+                run_sys_open_test();
+                return;
+        }
+        /* Shutdown and unregister */
+        kgdb_unregister_io_module(&kgdbts_io_ops);
+        configured = 0;
+}
+
+static int kgdbts_option_setup(char *opt)
+{
+        if (strlen(opt) > MAX_CONFIG_LEN) {
+                printk(KERN_ERR "kgdbts: config string too long\n");
+                return -ENOSPC;
+        }
+        strcpy(config, opt);
+
+        verbose = 0;
+        if (strstr(config, "V1"))
+                verbose = 1;
+        if (strstr(config, "V2"))
+                verbose = 2;
+
+        return 0;
+}
+
+__setup("kgdbts=", kgdbts_option_setup);
+
+static int configure_kgdbts(void)
+{
+        int err = 0;
+
+        if (!strlen(config) || isspace(config[0]))
+                goto noconfig;
+        err = kgdbts_option_setup(config);
+        if (err)
+                goto noconfig;
+
+        final_ack = 0;
+        run_plant_and_detach_test(1);
+
+        err = kgdb_register_io_module(&kgdbts_io_ops);
+        if (err) {
+                configured = 0;
+                return err;
+        }
+        configured = 1;
+        kgdbts_run_tests();
+
+        return err;
+
+noconfig:
+        config[0] = 0;
+        configured = 0;
+
+        return err;
+}
+
+static int __init init_kgdbts(void)
+{
+        /* Already configured? */
+        if (configured == 1)
+                return 0;
+
+        return configure_kgdbts();
+}
+
+static void cleanup_kgdbts(void)
+{
+        if (configured == 1)
+                kgdb_unregister_io_module(&kgdbts_io_ops);
+}
+
+static int kgdbts_get_char(void)
+{
+        int val = 0;
+
+        if (ts.run_test)
+                val = ts.run_test(1, 0);
+
+        return val;
+}
+
+static void kgdbts_put_char(u8 chr)
+{
+        if (ts.run_test)
+                ts.run_test(0, chr);
+}
+
+static int param_set_kgdbts_var(const char *kmessage, struct kernel_param *kp)
+{
+        int len = strlen(kmessage);
+
+        if (len >= MAX_CONFIG_LEN) {
+                printk(KERN_ERR "kgdbts: config string too long\n");
+                return -ENOSPC;
+        }
+
+        /* Only copy in the string if the init function has not run yet */
+        if (configured < 0) {
+                strcpy(config, kmessage);
+                return 0;
+        }
+
+        if (kgdb_connected) {
+                printk(KERN_ERR
+               "kgdbts: Cannot reconfigure while KGDB is connected.\n");
+
+                return -EBUSY;
+        }
+
+        strcpy(config, kmessage);
+        /* Chop out \n char as a result of echo */
+        if (config[len - 1] == '\n')
+                config[len - 1] = '\0';
+
+        if (configured == 1)
+                cleanup_kgdbts();
+
+        /* Go and configure with the new params. */
+        return configure_kgdbts();
+}
+
+static void kgdbts_pre_exp_handler(void)
+{
+        /* Increment the module count when the debugger is active */
+        if (!kgdb_connected)
+                try_module_get(THIS_MODULE);
+}
+
+static void kgdbts_post_exp_handler(void)
+{
+        /* decrement the module count when the debugger detaches */
+        if (!kgdb_connected)
+                module_put(THIS_MODULE);
+}
+
+static struct kgdb_io kgdbts_io_ops = {
+        .name                   = "kgdbts",
+        .read_char              = kgdbts_get_char,
+        .write_char             = kgdbts_put_char,
+        .pre_exception          = kgdbts_pre_exp_handler,
+        .post_exception         = kgdbts_post_exp_handler,
+};
+
+module_init(init_kgdbts);
+module_exit(cleanup_kgdbts);
+module_param_call(kgdbts, param_set_kgdbts_var, param_get_string, &kps, 0644);
+MODULE_PARM_DESC(kgdbts, "<A|V1|V2>[F#|S#][N#]");
+MODULE_DESCRIPTION("KGDB Test Suite");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Wind River Systems, Inc.");
+
diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
index 77f7a7f0646e..96a585e1cee8 100644
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -1740,6 +1740,60 @@ static inline void wait_for_xmitr(struct uart_8250_port *up, int bits)
         }
 }
 
+#ifdef CONFIG_CONSOLE_POLL
+/*
+ * Console polling routines for writing and reading from the uart while
+ * in an interrupt or debug context.
+ */
+
+static int serial8250_get_poll_char(struct uart_port *port)
+{
+        struct uart_8250_port *up = (struct uart_8250_port *)port;
+        unsigned char lsr = serial_inp(up, UART_LSR);
+
+        while (!(lsr & UART_LSR_DR))
+                lsr = serial_inp(up, UART_LSR);
+
+        return serial_inp(up, UART_RX);
+}
+
+
+static void serial8250_put_poll_char(struct uart_port *port,
+                         unsigned char c)
+{
+        unsigned int ier;
+        struct uart_8250_port *up = (struct uart_8250_port *)port;
+
+        /*
+         *      First save the IER then disable the interrupts
+         */
+        ier = serial_in(up, UART_IER);
+        if (up->capabilities & UART_CAP_UUE)
+                serial_out(up, UART_IER, UART_IER_UUE);
+        else
+                serial_out(up, UART_IER, 0);
+
+        wait_for_xmitr(up, BOTH_EMPTY);
+        /*
+         *      Send the character out.
+         *      If a LF, also do CR...
+         */
+        serial_out(up, UART_TX, c);
+        if (c == 10) {
+                wait_for_xmitr(up, BOTH_EMPTY);
+                serial_out(up, UART_TX, 13);
+        }
+
+        /*
+         *      Finally, wait for transmitter to become empty
+         *      and restore the IER
+         */
+        wait_for_xmitr(up, BOTH_EMPTY);
+        serial_out(up, UART_IER, ier);
+}
+
+#endif /* CONFIG_CONSOLE_POLL */
+
 static int serial8250_startup(struct uart_port *port)
 {
         struct uart_8250_port *up = (struct uart_8250_port *)port;
@@ -2386,6 +2440,10 @@ static struct uart_ops serial8250_pops = {
         .request_port   = serial8250_request_port,
         .config_port    = serial8250_config_port,
         .verify_port    = serial8250_verify_port,
+#ifdef CONFIG_CONSOLE_POLL
+        .poll_get_char = serial8250_get_poll_char,
+        .poll_put_char = serial8250_put_poll_char,
+#endif
 };
 
 static struct uart_8250_port serial8250_ports[UART_NR];
diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig
index cf627cd1b4c8..f7cd9504d811 100644
--- a/drivers/serial/Kconfig
+++ b/drivers/serial/Kconfig
@@ -961,6 +961,9 @@ config SERIAL_CORE
 config SERIAL_CORE_CONSOLE
         bool
 
+config CONSOLE_POLL
+        bool
+
 config SERIAL_68328
         bool "68328 serial support"
         depends on M68328 || M68EZ328 || M68VZ328
diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile
index 640cfe44a56d..3cbea5494724 100644
--- a/drivers/serial/Makefile
+++ b/drivers/serial/Makefile
@@ -66,4 +66,5 @@ obj-$(CONFIG_SERIAL_UARTLITE) += uartlite.o
 obj-$(CONFIG_SERIAL_NETX) += netx-serial.o
 obj-$(CONFIG_SERIAL_OF_PLATFORM) += of_serial.o
 obj-$(CONFIG_SERIAL_KS8695) += serial_ks8695.o
+obj-$(CONFIG_KGDB_SERIAL_CONSOLE) += kgdboc.o
 obj-$(CONFIG_SERIAL_QE) += ucc_uart.o
diff --git a/drivers/serial/amba-pl011.c b/drivers/serial/amba-pl011.c
index 40604a092921..08adc1de4a79 100644
--- a/drivers/serial/amba-pl011.c
+++ b/drivers/serial/amba-pl011.c
@@ -314,6 +314,32 @@ static void pl011_break_ctl(struct uart_port *port, int break_state)
         spin_unlock_irqrestore(&uap->port.lock, flags);
 }
 
+#ifdef CONFIG_CONSOLE_POLL
+static int pl010_get_poll_char(struct uart_port *port)
+{
+        struct uart_amba_port *uap = (struct uart_amba_port *)port;
+        unsigned int status;
+
+        do {
+                status = readw(uap->port.membase + UART01x_FR);
+        } while (status & UART01x_FR_RXFE);
+
+        return readw(uap->port.membase + UART01x_DR);
+}
+
+static void pl010_put_poll_char(struct uart_port *port,
+                         unsigned char ch)
+{
+        struct uart_amba_port *uap = (struct uart_amba_port *)port;
+
+        while (readw(uap->port.membase + UART01x_FR) & UART01x_FR_TXFF)
+                barrier();
+
+        writew(ch, uap->port.membase + UART01x_DR);
+}
+
+#endif /* CONFIG_CONSOLE_POLL */
+
 static int pl011_startup(struct uart_port *port)
 {
         struct uart_amba_port *uap = (struct uart_amba_port *)port;
@@ -572,6 +598,10 @@ static struct uart_ops amba_pl011_pops = {
         .request_port   = pl010_request_port,
         .config_port    = pl010_config_port,
         .verify_port    = pl010_verify_port,
+#ifdef CONFIG_CONSOLE_POLL
+        .poll_get_char = pl010_get_poll_char,
+        .poll_put_char = pl010_put_poll_char,
+#endif
 };
 
 static struct uart_amba_port *amba_ports[UART_NR];
diff --git a/drivers/serial/kgdboc.c b/drivers/serial/kgdboc.c
new file mode 100644
index 000000000000..9cf03327386a
--- /dev/null
+++ b/drivers/serial/kgdboc.c
@@ -0,0 +1,168 @@
+/*
+ * Based on the same principle as kgdboe using the NETPOLL api, this
+ * driver uses a console polling api to implement a gdb serial inteface
+ * which is multiplexed on a console port.
+ *
+ * Maintainer: Jason Wessel <jason.wessel@windriver.com>
+ *
+ * 2007-2008 (c) Jason Wessel - Wind River Systems, Inc.
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+#include <linux/kernel.h>
+#include <linux/ctype.h>
+#include <linux/kgdb.h>
+#include <linux/tty.h>
+
+#define MAX_CONFIG_LEN          40
+
+static struct kgdb_io           kgdboc_io_ops;
+
+/* -1 = init not run yet, 0 = unconfigured, 1 = configured. */
+static int configured           = -1;
+
+static char config[MAX_CONFIG_LEN];
+static struct kparam_string kps = {
+        .string                 = config,
+        .maxlen                 = MAX_CONFIG_LEN,
+};
+
+static struct tty_driver        *kgdb_tty_driver;
+static int                      kgdb_tty_line;
+
+static int kgdboc_option_setup(char *opt)
+{
+        if (strlen(opt) > MAX_CONFIG_LEN) {
+                printk(KERN_ERR "kgdboc: config string too long\n");
+                return -ENOSPC;
+        }
+        strcpy(config, opt);
+
+        return 0;
+}
+
+__setup("kgdboc=", kgdboc_option_setup);
+
+static int configure_kgdboc(void)
+{
+        struct tty_driver *p;
+        int tty_line = 0;
+        int err;
+
+        err = kgdboc_option_setup(config);
+        if (err || !strlen(config) || isspace(config[0]))
+                goto noconfig;
+
+        err = -ENODEV;
+
+        p = tty_find_polling_driver(config, &tty_line);
+        if (!p)
+                goto noconfig;
+
+        kgdb_tty_driver = p;
+        kgdb_tty_line = tty_line;
+
+        err = kgdb_register_io_module(&kgdboc_io_ops);
+        if (err)
+                goto noconfig;
+
+        configured = 1;
+
+        return 0;
+
+noconfig:
+        config[0] = 0;
+        configured = 0;
+
+        return err;
+}
+
+static int __init init_kgdboc(void)
+{
+        /* Already configured? */
+        if (configured == 1)
+                return 0;
+
+        return configure_kgdboc();
+}
+
+static void cleanup_kgdboc(void)
+{
+        if (configured == 1)
+                kgdb_unregister_io_module(&kgdboc_io_ops);
+}
+
+static int kgdboc_get_char(void)
+{
+        return kgdb_tty_driver->poll_get_char(kgdb_tty_driver, kgdb_tty_line);
+}
+
+static void kgdboc_put_char(u8 chr)
+{
+        kgdb_tty_driver->poll_put_char(kgdb_tty_driver, kgdb_tty_line, chr);
+}
+
+static int param_set_kgdboc_var(const char *kmessage, struct kernel_param *kp)
+{
+        int len = strlen(kmessage);
+
+        if (len >= MAX_CONFIG_LEN) {
+                printk(KERN_ERR "kgdboc: config string too long\n");
+                return -ENOSPC;
+        }
+
+        /* Only copy in the string if the init function has not run yet */
+        if (configured < 0) {
+                strcpy(config, kmessage);
+                return 0;
+        }
+
+        if (kgdb_connected) {
+                printk(KERN_ERR
+                       "kgdboc: Cannot reconfigure while KGDB is connected.\n");
+
+                return -EBUSY;
+        }
+
+        strcpy(config, kmessage);
+        /* Chop out \n char as a result of echo */
+        if (config[len - 1] == '\n')
+                config[len - 1] = '\0';
+
+        if (configured == 1)
+                cleanup_kgdboc();
+
+        /* Go and configure with the new params. */
+        return configure_kgdboc();
+}
+
+static void kgdboc_pre_exp_handler(void)
+{
+        /* Increment the module count when the debugger is active */
+        if (!kgdb_connected)
+                try_module_get(THIS_MODULE);
+}
+
+static void kgdboc_post_exp_handler(void)
+{
+        /* decrement the module count when the debugger detaches */
+        if (!kgdb_connected)
+                module_put(THIS_MODULE);
+}
+
+static struct kgdb_io kgdboc_io_ops = {
+        .name                   = "kgdboc",
+        .read_char              = kgdboc_get_char,
+        .write_char             = kgdboc_put_char,
+        .pre_exception          = kgdboc_pre_exp_handler,
+        .post_exception         = kgdboc_post_exp_handler,
+};
+
+module_init(init_kgdboc);
+module_exit(cleanup_kgdboc);
+module_param_call(kgdboc, param_set_kgdboc_var, param_get_string, &kps, 0644);
+MODULE_PARM_DESC(kgdboc, "<serial_device>[,baud]");
+MODULE_DESCRIPTION("KGDB Console TTY Driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c
index 0f5a17987cca..c32c1ca75f63 100644
--- a/drivers/serial/serial_core.c
+++ b/drivers/serial/serial_core.c
@@ -1771,7 +1771,7 @@ static int uart_read_proc(char *page, char **start, off_t off,
 }
 #endif
 
-#ifdef CONFIG_SERIAL_CORE_CONSOLE
+#if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
 /*
  *      uart_console_write - write a console message to a serial port
  *      @port: the port to write the message
@@ -1827,7 +1827,7 @@ uart_get_console(struct uart_port *ports, int nr, struct console *co)
  *      options.  The format of the string is <baud><parity><bits><flow>,
  *      eg: 115200n8r
  */
-void __init
+void
 uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow)
 {
         char *s = options;
@@ -1842,6 +1842,7 @@ uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow)
         if (*s)
                 *flow = *s;
 }
+EXPORT_SYMBOL_GPL(uart_parse_options);
 
 struct baud_rates {
         unsigned int rate;
@@ -1872,7 +1873,7 @@ static const struct baud_rates baud_rates[] = {
  *      @bits: number of data bits
  *      @flow: flow control character - 'r' (rts)
  */
-int __init
+int
 uart_set_options(struct uart_port *port, struct console *co,
                  int baud, int parity, int bits, int flow)
 {
@@ -1924,10 +1925,16 @@ uart_set_options(struct uart_port *port, struct console *co,
         port->mctrl |= TIOCM_DTR;
 
         port->ops->set_termios(port, &termios, &dummy);
-        co->cflag = termios.c_cflag;
+        /*
+         * Allow the setting of the UART parameters with a NULL console
+         * too:
+         */
+        if (co)
+                co->cflag = termios.c_cflag;
 
         return 0;
 }
+EXPORT_SYMBOL_GPL(uart_set_options);
 #endif /* CONFIG_SERIAL_CORE_CONSOLE */
 
 static void uart_change_pm(struct uart_state *state, int pm_state)
@@ -2182,6 +2189,60 @@ uart_configure_port(struct uart_driver *drv, struct uart_state *state,
         }
 }
 
+#ifdef CONFIG_CONSOLE_POLL
+
+static int uart_poll_init(struct tty_driver *driver, int line, char *options)
+{
+        struct uart_driver *drv = driver->driver_state;
+        struct uart_state *state = drv->state + line;
+        struct uart_port *port;
+        int baud = 9600;
+        int bits = 8;
+        int parity = 'n';
+        int flow = 'n';
+
+        if (!state || !state->port)
+                return -1;
+
+        port = state->port;
+        if (!(port->ops->poll_get_char && port->ops->poll_put_char))
+                return -1;
+
+        if (options) {
+                uart_parse_options(options, &baud, &parity, &bits, &flow);
+                return uart_set_options(port, NULL, baud, parity, bits, flow);
+        }
+
+        return 0;
+}
+
+static int uart_poll_get_char(struct tty_driver *driver, int line)
+{
+        struct uart_driver *drv = driver->driver_state;
+        struct uart_state *state = drv->state + line;
+        struct uart_port *port;
+
+        if (!state || !state->port)
+                return -1;
+
+        port = state->port;
+        return port->ops->poll_get_char(port);
+}
+
+static void uart_poll_put_char(struct tty_driver *driver, int line, char ch)
+{
+        struct uart_driver *drv = driver->driver_state;
+        struct uart_state *state = drv->state + line;
+        struct uart_port *port;
+
+        if (!state || !state->port)
+                return;
+
+        port = state->port;
+        port->ops->poll_put_char(port, ch);
+}
+#endif
+
 static const struct tty_operations uart_ops = {
         .open           = uart_open,
         .close          = uart_close,
@@ -2206,6 +2267,11 @@ static const struct tty_operations uart_ops = {
 #endif
         .tiocmget       = uart_tiocmget,
         .tiocmset       = uart_tiocmset,
+#ifdef CONFIG_CONSOLE_POLL
+        .poll_init      = uart_poll_init,
+        .poll_get_char  = uart_poll_get_char,
+        .poll_put_char  = uart_poll_put_char,
+#endif
 };
 
 /**