Commit 28947198 authored by Dmitry Osipenko's avatar Dmitry Osipenko Committed by Krzysztof Kozlowski

memory: tegra20: Protect debug code with a lock

Simultaneous accesses to MC_STAT h/w shouldn't be allowed since one
collection process stomps on another. There is no good reason for
polling stats in parallel in practice, nevertheless let's add a
protection lock, just for consistency.
Signed-off-by: default avatarDmitry Osipenko <digetx@gmail.com>
Link: https://lore.kernel.org/r/20210323210446.24867-2-digetx@gmail.comSigned-off-by: default avatarKrzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
parent 7ebb09db
...@@ -5,6 +5,7 @@ ...@@ -5,6 +5,7 @@
#include <linux/bitfield.h> #include <linux/bitfield.h>
#include <linux/delay.h> #include <linux/delay.h>
#include <linux/mutex.h>
#include <linux/of_device.h> #include <linux/of_device.h>
#include <linux/slab.h> #include <linux/slab.h>
#include <linux/string.h> #include <linux/string.h>
...@@ -55,6 +56,8 @@ ...@@ -55,6 +56,8 @@
/* we store collected statistics as a fixed point values */ /* we store collected statistics as a fixed point values */
#define MC_FX_FRAC_SCALE 100 #define MC_FX_FRAC_SCALE 100
static DEFINE_MUTEX(tegra20_mc_stat_lock);
struct tegra20_mc_stat_gather { struct tegra20_mc_stat_gather {
unsigned int pri_filter; unsigned int pri_filter;
unsigned int pri_event; unsigned int pri_event;
...@@ -615,8 +618,12 @@ static int tegra20_mc_stats_show(struct seq_file *s, void *unused) ...@@ -615,8 +618,12 @@ static int tegra20_mc_stats_show(struct seq_file *s, void *unused)
if (!stats) if (!stats)
return -ENOMEM; return -ENOMEM;
mutex_lock(&tegra20_mc_stat_lock);
tegra20_mc_collect_stats(mc, stats); tegra20_mc_collect_stats(mc, stats);
mutex_unlock(&tegra20_mc_stat_lock);
seq_puts(s, "Memory client Events Timeout High priority Bandwidth ARB RW change Successive Page miss\n"); seq_puts(s, "Memory client Events Timeout High priority Bandwidth ARB RW change Successive Page miss\n");
seq_puts(s, "-----------------------------------------------------------------------------------------------------\n"); seq_puts(s, "-----------------------------------------------------------------------------------------------------\n");
......
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