sh/ftrace: Remove only user of ftrace_arch_read_dyn_info()

I noticed that there's only one user of ftrace_arch_read_dyn_info().
That was used a while ago during the NMI updating in x86, and superh
copied it to implement its version of handling NMIs during
stop_machine().

But that is a debug feature, and this code hasn't been touched since
2009. Also, x86 no longer does the ftrace updates with stop_machine()
and instead uses breakpoints. If superh needs to modify its code, it
should implement the breakpoint conversion, and remove stop_machine().
Which also gets rid of the NMI issue.

Anyway, I want to nuke ftrace_arch_read_dyn_info() and this gets rid of
the one user, which is for an arch that shouldn't need it anymore.

Link: http://lkml.kernel.org/r/20170626181749.2ce954d1@gandalf.local.home
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: linux-sh@vger.kernel.org
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

diff --git a/arch/sh/kernel/ftrace.c b/arch/sh/kernel/ftrace.c
index 53783978162e2d1c82c1f44b349f7530d650c341..d18724d186f3cf59022e4c5246b882bfed6f9d3f 100644 (file)
--- a/arch/sh/kernel/ftrace.c
+++ b/arch/sh/kernel/ftrace.c
@@ -96,19 +96,6 @@ static int mod_code_status;          /* holds return value of text write */
 static void *mod_code_ip;              /* holds the IP to write to */
 static void *mod_code_newcode;         /* holds the text to write to the IP */
 
-static unsigned nmi_wait_count;
-static atomic_t nmi_update_count = ATOMIC_INIT(0);
-
-int ftrace_arch_read_dyn_info(char *buf, int size)
-{
-       int r;
-
-       r = snprintf(buf, size, "%u %u",
-                    nmi_wait_count,
-                    atomic_read(&nmi_update_count));
-       return r;
-}
-
 static void clear_mod_flag(void)
 {
        int old = atomic_read(&nmi_running);
@@ -144,7 +131,6 @@ void arch_ftrace_nmi_enter(void)
        if (atomic_inc_return(&nmi_running) & MOD_CODE_WRITE_FLAG) {
                smp_rmb();
                ftrace_mod_code();
-               atomic_inc(&nmi_update_count);
        }
        /* Must have previous changes seen before executions */
        smp_mb();
@@ -165,8 +151,6 @@ static void wait_for_nmi_and_set_mod_flag(void)
        do {
                cpu_relax();
        } while (atomic_cmpxchg(&nmi_running, 0, MOD_CODE_WRITE_FLAG));
-
-       nmi_wait_count++;
 }
 
 static void wait_for_nmi(void)
@@ -177,8 +161,6 @@ static void wait_for_nmi(void)
        do {
                cpu_relax();
        } while (atomic_read(&nmi_running));
-
-       nmi_wait_count++;
 }
 
 static int