diff options
Diffstat (limited to 'sys/arch/i386/i386/db_mp.c')
| -rw-r--r-- | sys/arch/i386/i386/db_mp.c | 187 |
1 files changed, 187 insertions, 0 deletions
diff --git a/sys/arch/i386/i386/db_mp.c b/sys/arch/i386/i386/db_mp.c new file mode 100644 index 00000000000..0a859f08360 --- /dev/null +++ b/sys/arch/i386/i386/db_mp.c @@ -0,0 +1,187 @@ +/* $OpenBSD: db_mp.c,v 1.2 2004/06/13 21:49:15 niklas Exp $ */ + +/* + * Copyright (c) 2003 Andreas Gunnarsson + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * - Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * - Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following + * disclaimer in the documentation and/or other materials provided + * with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; + * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER + * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN + * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +#include <sys/types.h> +#include <sys/simplelock.h> + +#include <machine/db_machdep.h> + +#include <ddb/db_output.h> + +#define DDB_STATE_NOT_RUNNING 0 +#define DDB_STATE_RUNNING 1 + +struct SIMPLELOCK ddb_mp_slock; + +volatile int ddb_state = DDB_STATE_NOT_RUNNING; /* protected by ddb_mp_slock */ +volatile cpuid_t ddb_active_cpu; /* protected by ddb_mp_slock */ + +/* + * ddb_enter_ddb() is called when ddb is entered to stop the other + * CPUs. If another cpu is already in ddb we'll wait until it's finished. + */ +void +db_enter_ddb() +{ + int s, i; + + s = splhigh(); + SIMPLE_LOCK(&ddb_mp_slock); + + while (ddb_state == DDB_STATE_RUNNING + && ddb_active_cpu != cpu_number()) { + db_printf("CPU %d waiting to enter ddb\n", cpu_number()); + SIMPLE_UNLOCK(&ddb_mp_slock); + splx(s); + + /* Busy wait without locking, we'll confirm with lock later */ + while (ddb_state == DDB_STATE_RUNNING + && ddb_active_cpu != cpu_number()) + ; /* Do nothing */ + + s = splhigh(); + SIMPLE_LOCK(&ddb_mp_slock); + } + + ddb_state = DDB_STATE_RUNNING; + ddb_active_cpu = cpu_number(); + + for (i = 0; i < I386_MAXPROCS; i++) { + if (cpu_info[i] != NULL) { + if (i == cpu_number()) + cpu_info[i]->ci_ddb_paused = CI_DDB_INDDB; + else if (cpu_info[i]->ci_ddb_paused + != CI_DDB_STOPPED) { + cpu_info[i]->ci_ddb_paused = CI_DDB_SHOULDSTOP; + db_printf("Sending IPI to cpu %d\n", i); + i386_send_ipi(cpu_info[i], I386_IPI_DDB); + } + } + } + db_printf("CPU %d entering ddb\n", cpu_number()); + SIMPLE_UNLOCK(&ddb_mp_slock); + splx(s); +} + +void +db_leave_ddb() +{ + int s, i; + + s = splhigh(); + SIMPLE_LOCK(&ddb_mp_slock); + db_printf("CPU %d leaving ddb\n", cpu_number()); + for (i = 0; i < I386_MAXPROCS; i++) { + if (cpu_info[i] != NULL) { + cpu_info[i]->ci_ddb_paused = CI_DDB_RUNNING; + } + } + ddb_state = DDB_STATE_NOT_RUNNING; + SIMPLE_UNLOCK(&ddb_mp_slock); + splx(s); +} + +void +db_startcpu(int cpu) +{ + int s; + + if (cpu != cpu_number() && cpu_info[cpu] != NULL) { + s = splhigh(); + SIMPLE_LOCK(&ddb_mp_slock); + cpu_info[cpu]->ci_ddb_paused = CI_DDB_RUNNING; + SIMPLE_UNLOCK(&ddb_mp_slock); + splx(s); + } +} + +void +db_stopcpu(int cpu) +{ + int s; + + if (cpu != cpu_number() && cpu_info[cpu] != NULL) { + s = splhigh(); + SIMPLE_LOCK(&ddb_mp_slock); + cpu_info[cpu]->ci_ddb_paused = CI_DDB_SHOULDSTOP; + db_printf("Sending IPI to cpu %d\n", cpu); + SIMPLE_UNLOCK(&ddb_mp_slock); + splx(s); + i386_send_ipi(cpu_info[cpu], I386_IPI_DDB); + } +} + +void +db_movetocpu(int cpu) +{ + int s; + + s = splhigh(); + SIMPLE_LOCK(&ddb_mp_slock); + cpu_info[cpu]->ci_ddb_paused = CI_DDB_ENTERDDB; + db_printf("Sending IPI to cpu %d\n", cpu); + SIMPLE_UNLOCK(&ddb_mp_slock); + splx(s); + /* XXX If other CPU was running and IPI is lost, we lose. */ + i386_send_ipi(cpu_info[cpu], I386_IPI_DDB); +} + +void +i386_ipi_db(struct cpu_info *ci) +{ + int s; + + s = splhigh(); + SIMPLE_LOCK(&ddb_mp_slock); + db_printf("CPU %d received ddb IPI\n", cpu_number()); + while (ci->ci_ddb_paused == CI_DDB_SHOULDSTOP + || ci->ci_ddb_paused == CI_DDB_STOPPED) { + if (ci->ci_ddb_paused == CI_DDB_SHOULDSTOP) + ci->ci_ddb_paused = CI_DDB_STOPPED; + SIMPLE_UNLOCK(&ddb_mp_slock); + while (ci->ci_ddb_paused == CI_DDB_STOPPED) + ; /* Do nothing */ + SIMPLE_LOCK(&ddb_mp_slock); + } + if (ci->ci_ddb_paused == CI_DDB_ENTERDDB) { + ddb_state = DDB_STATE_RUNNING; + ddb_active_cpu = cpu_number(); + ci->ci_ddb_paused = CI_DDB_INDDB; + db_printf("CPU %d grabbing ddb\n", cpu_number()); + SIMPLE_UNLOCK(&ddb_mp_slock); + Debugger(); + SIMPLE_LOCK(&ddb_mp_slock); + ci->ci_ddb_paused = CI_DDB_RUNNING; + } + db_printf("CPU %d leaving ddb IPI handler\n", cpu_number()); + SIMPLE_UNLOCK(&ddb_mp_slock); + splx(s); +} |