summaryrefslogtreecommitdiff
path: root/arch/powerpc/xmon
diff options
context:
space:
mode:
authorGuilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com>2017-03-22 16:27:51 -0300
committerMichael Ellerman <mpe@ellerman.id.au>2017-03-28 10:52:01 +1100
commitde78ae6c9ef55d9ded036c8e29d9364e1ce5f6b7 (patch)
treee70328b63d61c53260098aef326628845f62d321 /arch/powerpc/xmon
parentb561783c7bfd4bcb18ad30e1410ee19500c36a7c (diff)
powerpc/xmon: add debugfs entry for xmon
Currently the xmon debugger is set only via kernel boot command-line. It's disabled by default, and can be enabled with "xmon=on" on the command-line. Also, xmon may be accessed via sysrq mechanism. But we cannot enable/disable xmon in runtime, it needs kernel reload. This patch introduces a debugfs entry for xmon, allowing user to query its current state and change it if desired. Basically, the "xmon" file to read from/write to is under the debugfs mount point, on powerpc directory. It's a simple attribute, value 0 meaning xmon is disabled and value 1 the opposite. Writing these states to the file will take immediate effect in the debugger. Signed-off-by: Guilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/xmon')
-rw-r--r--arch/powerpc/xmon/xmon.c31
1 files changed, 31 insertions, 0 deletions
diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index 25a32815f310..0fab9d7349eb 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -29,6 +29,10 @@
#include <linux/nmi.h>
#include <linux/ctype.h>
+#ifdef CONFIG_DEBUG_FS
+#include <linux/debugfs.h>
+#endif
+
#include <asm/ptrace.h>
#include <asm/string.h>
#include <asm/prom.h>
@@ -3316,6 +3320,33 @@ static int __init setup_xmon_sysrq(void)
device_initcall(setup_xmon_sysrq);
#endif /* CONFIG_MAGIC_SYSRQ */
+#ifdef CONFIG_DEBUG_FS
+static int xmon_dbgfs_set(void *data, u64 val)
+{
+ xmon_on = !!val;
+ xmon_init(xmon_on);
+
+ return 0;
+}
+
+static int xmon_dbgfs_get(void *data, u64 *val)
+{
+ *val = xmon_on;
+ return 0;
+}
+
+DEFINE_SIMPLE_ATTRIBUTE(xmon_dbgfs_ops, xmon_dbgfs_get,
+ xmon_dbgfs_set, "%llu\n");
+
+static int __init setup_xmon_dbgfs(void)
+{
+ debugfs_create_file("xmon", 0600, powerpc_debugfs_root, NULL,
+ &xmon_dbgfs_ops);
+ return 0;
+}
+device_initcall(setup_xmon_dbgfs);
+#endif /* CONFIG_DEBUG_FS */
+
static int xmon_early __initdata;
static int __init early_parse_xmon(char *p)