x86: cpu_debug add write support for MSRs

Supported write flag for registers.
currently write is enabled only for PMC MSR.

[root@ht]# cat /sys/kernel/debug/x86/cpu/cpu1/pmc/0x300/value
0x0

[root@ht]# echo 1234 > /sys/kernel/debug/x86/cpu/cpu1/pmc/0x300/value
[root@ht]# cat /sys/kernel/debug/x86/cpu/cpu1/pmc/0x300/value
0x4d2

[root@ht]# echo 0x1234 > /sys/kernel/debug/x86/cpu/cpu1/pmc/0x300/value
[root@ht]# cat /sys/kernel/debug/x86/cpu/cpu1/pmc/0x300/value
0x1234

Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 11 insertions, 5 deletions

diff --git a/arch/x86/include/asm/cpu_debug.h b/arch/x86/include/asm/cpu_debug.h
index d24d64fcee0..56f1635e461 100755
--- a/arch/x86/include/asm/cpu_debug.h
+++ b/arch/x86/include/asm/cpu_debug.h
@@ -171,16 +171,22 @@ struct cpu_private {
 struct cpu_debug_base {
         char                    *name;          /* Register name        */
         unsigned                flag;           /* Register flag        */
+        unsigned                write;          /* Register write flag  */
 };
 
-struct cpu_cpuX_base {
-        struct dentry           *dentry;        /* Register dentry      */
-        int                     init;           /* Register index file  */
-};
-
+/*
+ * Currently it looks similar to cpu_debug_base but once we add more files
+ * cpu_file_base will go in different direction
+ */
 struct cpu_file_base {
         char                    *name;          /* Register file name   */
         unsigned                flag;           /* Register file flag   */
+        unsigned                write;          /* Register write flag  */
+};
+
+struct cpu_cpuX_base {
+        struct dentry           *dentry;        /* Register dentry      */
+        int                     init;           /* Register index file  */
 };
 
 struct cpu_debug_range {