[PATCH 4/7 v2] RAS, debugfs: Add debugfs interface for RAS subsystem
From: Chen, Gong <hidden>
Date: 2014-05-15 09:04:12
Subsystem:
ras infrastructure, the rest · Maintainers:
Tony Luck, Borislav Petkov, Linus Torvalds
Implement a new debugfs interface for RAS susbsystem. A file named daemon_active is added there accordingly. This file is used to track if user space daemon enables perf/trace interface or not. One can track which daemon opens it via "lsof /path/to/debugfs/ras/daemon_active". v2 -> v1: Change file access mode from 0444 to 0400. Signed-off-by: Chen, Gong <redacted> --- drivers/ras/Makefile | 2 +- drivers/ras/debugfs.c | 57 +++++++++++++++++++++++++++++++++++++++++++++++++++ drivers/ras/ras.c | 14 +++++++++++++ include/linux/ras.h | 15 ++++++++++++++ 4 files changed, 87 insertions(+), 1 deletion(-) create mode 100644 drivers/ras/debugfs.c create mode 100644 include/linux/ras.h
diff --git a/drivers/ras/Makefile b/drivers/ras/Makefile
index 223e806..d7f7334 100644
--- a/drivers/ras/Makefile
+++ b/drivers/ras/Makefile@@ -1 +1 @@ -obj-$(CONFIG_RAS) += ras.o +obj-$(CONFIG_RAS) += ras.o debugfs.o
diff --git a/drivers/ras/debugfs.c b/drivers/ras/debugfs.c
new file mode 100644
index 0000000..d0bc389
--- /dev/null
+++ b/drivers/ras/debugfs.c@@ -0,0 +1,57 @@ +#include <linux/debugfs.h> + +struct dentry *ras_debugfs_dir; +EXPORT_SYMBOL_GPL(ras_debugfs_dir); + +static atomic_t trace_count = ATOMIC_INIT(0); + +int ras_userspace_consumers(void) +{ + return atomic_read(&trace_count); +} +EXPORT_SYMBOL_GPL(ras_userspace_consumers); + +static int trace_show(struct seq_file *m, void *v) +{ + return atomic_read(&trace_count); +} + +static int trace_open(struct inode *inode, struct file *file) +{ + atomic_inc(&trace_count); + return single_open(file, trace_show, NULL); +} + +static int trace_release(struct inode *inode, struct file *file) +{ + atomic_dec(&trace_count); + return single_release(inode, file); +} + +static const struct file_operations trace_fops = { + .open = trace_open, + .read = seq_read, + .llseek = seq_lseek, + .release = trace_release, +}; + +int __init ras_add_daemon_trace(void) +{ + struct dentry *fentry; + + if (!ras_debugfs_dir) + return -ENOENT; + + fentry = debugfs_create_file("daemon_active", S_IRUSR, ras_debugfs_dir, + NULL, &trace_fops); + if (!fentry) + return -ENODEV; + + return 0; + +} + +void __init ras_debugfs_init(void) +{ + ras_debugfs_dir = debugfs_create_dir("ras", NULL); +}
diff --git a/drivers/ras/ras.c b/drivers/ras/ras.c
index b0c6ed1..4cac43a 100644
--- a/drivers/ras/ras.c
+++ b/drivers/ras/ras.c@@ -5,8 +5,22 @@ * Chen, Gong <gong.chen@linux.intel.com> */ +#include <linux/init.h> +#include <linux/ras.h> + #define CREATE_TRACE_POINTS #define TRACE_INCLUDE_PATH ../../include/ras #include <ras/ras_event.h> +static int __init ras_init(void) +{ + int rc = 0; + + ras_debugfs_init(); + rc = ras_add_daemon_trace(); + + return rc; +} +subsys_initcall(ras_init); + EXPORT_TRACEPOINT_SYMBOL_GPL(mc_event);
diff --git a/include/linux/ras.h b/include/linux/ras.h
new file mode 100644
index 0000000..af53248
--- /dev/null
+++ b/include/linux/ras.h@@ -0,0 +1,15 @@ +#ifndef __RAS_H__ +#define __RAS_H__ + +#ifdef CONFIG_DEBUG_FS +extern struct dentry *ras_debugfs_dir; +int ras_userspace_consumers(void); +void ras_debugfs_init(void); +int ras_add_daemon_trace(void); +#else +static inline int ras_userspace_consumers(void) { return 0; } +static inline void ras_debugfs_init(void) { return; } +static inline int ras_add_daemon_trace(void) { return 0; } +#endif + +#endif
--
2.0.0.rc0