diff options
Diffstat (limited to 'drivers/s390/crypto/ap_bus.c')
| -rw-r--r-- | drivers/s390/crypto/ap_bus.c | 63 |
1 files changed, 53 insertions, 10 deletions
diff --git a/drivers/s390/crypto/ap_bus.c b/drivers/s390/crypto/ap_bus.c index a1ab3e3efd1..62b6b55230d 100644 --- a/drivers/s390/crypto/ap_bus.c +++ b/drivers/s390/crypto/ap_bus.c @@ -34,13 +34,15 @@ #include <linux/mutex.h> #include <asm/s390_rdev.h> #include <asm/reset.h> +#include <linux/hrtimer.h> +#include <linux/ktime.h> #include "ap_bus.h" /* Some prototypes. */ static void ap_scan_bus(struct work_struct *); static void ap_poll_all(unsigned long); -static void ap_poll_timeout(unsigned long); +static enum hrtimer_restart ap_poll_timeout(struct hrtimer *); static int ap_poll_thread_start(void); static void ap_poll_thread_stop(void); static void ap_request_timeout(unsigned long); @@ -80,12 +82,15 @@ static DECLARE_WORK(ap_config_work, ap_scan_bus); /* * Tasklet & timer for AP request polling. */ -static struct timer_list ap_poll_timer = TIMER_INITIALIZER(ap_poll_timeout,0,0); static DECLARE_TASKLET(ap_tasklet, ap_poll_all, 0); static atomic_t ap_poll_requests = ATOMIC_INIT(0); static DECLARE_WAIT_QUEUE_HEAD(ap_poll_wait); static struct task_struct *ap_poll_kthread = NULL; static DEFINE_MUTEX(ap_poll_thread_mutex); +static struct hrtimer ap_poll_timer; +/* In LPAR poll with 4kHz frequency. Poll every 250000 nanoseconds. + * If z/VM change to 1500000 nanoseconds to adjust to z/VM polling.*/ +static unsigned long long poll_timeout = 250000; /** * ap_intructions_available() - Test if AP instructions are available. @@ -636,11 +641,39 @@ static ssize_t ap_poll_thread_store(struct bus_type *bus, static BUS_ATTR(poll_thread, 0644, ap_poll_thread_show, ap_poll_thread_store); +static ssize_t poll_timeout_show(struct bus_type *bus, char *buf) +{ + return snprintf(buf, PAGE_SIZE, "%llu\n", poll_timeout); +} + +static ssize_t poll_timeout_store(struct bus_type *bus, const char *buf, + size_t count) +{ + unsigned long long time; + ktime_t hr_time; + + /* 120 seconds = maximum poll interval */ + if (sscanf(buf, "%llu\n", &time) != 1 || time < 1 || time > 120000000000) + return -EINVAL; + poll_timeout = time; + hr_time = ktime_set(0, poll_timeout); + + if (!hrtimer_is_queued(&ap_poll_timer) || + !hrtimer_forward(&ap_poll_timer, ap_poll_timer.expires, hr_time)) { + ap_poll_timer.expires = hr_time; + hrtimer_start(&ap_poll_timer, hr_time, HRTIMER_MODE_ABS); + } + return count; +} + +static BUS_ATTR(poll_timeout, 0644, poll_timeout_show, poll_timeout_store); + static struct bus_attribute *const ap_bus_attrs[] = { &bus_attr_ap_domain, &bus_attr_config_time, &bus_attr_poll_thread, - NULL + &bus_attr_poll_timeout, + NULL, }; /** @@ -895,9 +928,10 @@ ap_config_timeout(unsigned long ptr) */ static inline void ap_schedule_poll_timer(void) { - if (timer_pending(&ap_poll_timer)) + if (hrtimer_is_queued(&ap_poll_timer)) return; - mod_timer(&ap_poll_timer, jiffies + AP_POLL_TIME); + hrtimer_start(&ap_poll_timer, ktime_set(0, poll_timeout), + HRTIMER_MODE_ABS); } /** @@ -1115,13 +1149,14 @@ EXPORT_SYMBOL(ap_cancel_message); /** * ap_poll_timeout(): AP receive polling for finished AP requests. - * @unused: Unused variable. + * @unused: Unused pointer. * - * Schedules the AP tasklet. + * Schedules the AP tasklet using a high resolution timer. */ -static void ap_poll_timeout(unsigned long unused) +static enum hrtimer_restart ap_poll_timeout(struct hrtimer *unused) { tasklet_schedule(&ap_tasklet); + return HRTIMER_NORESTART; } /** @@ -1344,6 +1379,14 @@ int __init ap_module_init(void) ap_config_timer.expires = jiffies + ap_config_time * HZ; add_timer(&ap_config_timer); + /* Setup the high resultion poll timer. + * If we are running under z/VM adjust polling to z/VM polling rate. + */ + if (MACHINE_IS_VM) + poll_timeout = 1500000; + hrtimer_init(&ap_poll_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS); + ap_poll_timer.function = ap_poll_timeout; + /* Start the low priority AP bus poll thread. */ if (ap_thread_flag) { rc = ap_poll_thread_start(); @@ -1355,7 +1398,7 @@ int __init ap_module_init(void) out_work: del_timer_sync(&ap_config_timer); - del_timer_sync(&ap_poll_timer); + hrtimer_cancel(&ap_poll_timer); destroy_workqueue(ap_work_queue); out_root: s390_root_dev_unregister(ap_root_device); @@ -1386,7 +1429,7 @@ void ap_module_exit(void) ap_reset_domain(); ap_poll_thread_stop(); del_timer_sync(&ap_config_timer); - del_timer_sync(&ap_poll_timer); + hrtimer_cancel(&ap_poll_timer); destroy_workqueue(ap_work_queue); tasklet_kill(&ap_tasklet); s390_root_dev_unregister(ap_root_device); |