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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>
hifive-unleashed-5.1
Steven Rostedt 2017-06-26 18:17:49 -04:00 committed by Steven Rostedt (VMware)
parent 8c08f0d5c6
commit fbb789f0d6
1 changed files with 0 additions and 18 deletions
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18
arch/sh/kernel/ftrace.c
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@ -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