diff options
| -rw-r--r-- | drivers/resctrl/mpam_devices.c | 12 | ||||
| -rw-r--r-- | drivers/resctrl/mpam_internal.h | 8 |
2 files changed, 20 insertions, 0 deletions
diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c index 21fccc3ff002..c126a95490f1 100644 --- a/drivers/resctrl/mpam_devices.c +++ b/drivers/resctrl/mpam_devices.c @@ -29,6 +29,8 @@ #include "mpam_internal.h" +DEFINE_STATIC_KEY_FALSE(mpam_enabled); /* This moves to arch code */ + /* * mpam_list_lock protects the SRCU lists when writing. Once the * mpam_enabled key is enabled these lists are read-only, @@ -936,6 +938,9 @@ static int mpam_discovery_cpu_online(unsigned int cpu) struct mpam_msc *msc; bool new_device_probed = false; + if (mpam_is_enabled()) + return 0; + guard(srcu)(&mpam_srcu); list_for_each_entry_srcu(msc, &mpam_all_msc, all_msc_list, srcu_read_lock_held(&mpam_srcu)) { @@ -1471,6 +1476,10 @@ static irqreturn_t __mpam_irq_handler(int irq, struct mpam_msc *msc) /* Disable this interrupt. */ mpam_disable_msc_ecr(msc); + /* Are we racing with the thread disabling MPAM? */ + if (!mpam_is_enabled()) + return IRQ_HANDLED; + /* * Schedule the teardown work. Don't use a threaded IRQ as we can't * unregister the interrupt from the threaded part of the handler. @@ -1605,6 +1614,7 @@ static void mpam_enable_once(void) return; } + static_branch_enable(&mpam_enabled); mpam_register_cpuhp_callbacks(mpam_cpu_online, mpam_cpu_offline, "mpam:online"); @@ -1671,6 +1681,8 @@ void mpam_disable(struct work_struct *ignored) } mutex_unlock(&mpam_cpuhp_state_lock); + static_branch_disable(&mpam_enabled); + mpam_unregister_irqs(); idx = srcu_read_lock(&mpam_srcu); diff --git a/drivers/resctrl/mpam_internal.h b/drivers/resctrl/mpam_internal.h index fa9d9a176a54..93a629f6e15a 100644 --- a/drivers/resctrl/mpam_internal.h +++ b/drivers/resctrl/mpam_internal.h @@ -9,6 +9,7 @@ #include <linux/bitmap.h> #include <linux/cpumask.h> #include <linux/io.h> +#include <linux/jump_label.h> #include <linux/llist.h> #include <linux/mutex.h> #include <linux/srcu.h> @@ -20,6 +21,13 @@ struct platform_device; +DECLARE_STATIC_KEY_FALSE(mpam_enabled); + +static inline bool mpam_is_enabled(void) +{ + return static_branch_likely(&mpam_enabled); +} + /* * Structures protected by SRCU may not be freed for a surprising amount of * time (especially if perf is running). To ensure the MPAM error interrupt can |