Merge tag 'sched-fifo-2020-08-04' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull sched/fifo updates from Ingo Molnar:
 "This adds the sched_set_fifo*() encapsulation APIs to remove static
  priority level knowledge from non-scheduler code.

  The three APIs for non-scheduler code to set SCHED_FIFO are:

   - sched_set_fifo()
   - sched_set_fifo_low()
   - sched_set_normal()

  These are two FIFO priority levels: default (high), and a 'low'
  priority level, plus sched_set_normal() to set the policy back to
  non-SCHED_FIFO.

  Since the changes affect a lot of non-scheduler code, we kept this in
  a separate tree"

* tag 'sched-fifo-2020-08-04' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits)
  sched,tracing: Convert to sched_set_fifo()
  sched: Remove sched_set_*() return value
  sched: Remove sched_setscheduler*() EXPORTs
  sched,psi: Convert to sched_set_fifo_low()
  sched,rcutorture: Convert to sched_set_fifo_low()
  sched,rcuperf: Convert to sched_set_fifo_low()
  sched,locktorture: Convert to sched_set_fifo()
  sched,irq: Convert to sched_set_fifo()
  sched,watchdog: Convert to sched_set_fifo()
  sched,serial: Convert to sched_set_fifo()
  sched,powerclamp: Convert to sched_set_fifo()
  sched,ion: Convert to sched_set_normal()
  sched,powercap: Convert to sched_set_fifo*()
  sched,spi: Convert to sched_set_fifo*()
  sched,mmc: Convert to sched_set_fifo*()
  sched,ivtv: Convert to sched_set_fifo*()
  sched,drm/scheduler: Convert to sched_set_fifo*()
  sched,msm: Convert to sched_set_fifo*()
  sched,psci: Convert to sched_set_fifo*()
  sched,drbd: Convert to sched_set_fifo*()
  ...

15 files changed, 18 insertions, 63 deletions

diff --git a/drivers/acpi/acpi_pad.c b/drivers/acpi/acpi_pad.c
index 6cc4c92d9ff9..b8745ce48a47 100644
--- a/drivers/acpi/acpi_pad.c
+++ b/drivers/acpi/acpi_pad.c
@@ -136,12 +136,11 @@ static unsigned int idle_pct = 5; /* percentage */
 static unsigned int round_robin_time = 1; /* second */
 static int power_saving_thread(void *data)
 {
-	struct sched_param param = {.sched_priority = 1};
 	int do_sleep;
 	unsigned int tsk_index = (unsigned long)data;
 	u64 last_jiffies = 0;
 
-	sched_setscheduler(current, SCHED_RR, &param);
+	sched_set_fifo_low(current);
 
 	while (!kthread_should_stop()) {
 		unsigned long expire_time;
diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index c74f561b4eab..1d17593f5d2b 100644
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -6019,11 +6019,8 @@ int drbd_ack_receiver(struct drbd_thread *thi)
 	unsigned int header_size = drbd_header_size(connection);
 	int expect   = header_size;
 	bool ping_timeout_active = false;
-	struct sched_param param = { .sched_priority = 2 };
 
-	rv = sched_setscheduler(current, SCHED_RR, &param);
-	if (rv < 0)
-		drbd_err(connection, "drbd_ack_receiver: ERROR set priority, ret=%d\n", rv);
+	sched_set_fifo_low(current);
 
 	while (get_t_state(thi) == RUNNING) {
 		drbd_thread_current_set_cpu(thi);
diff --git a/drivers/firmware/psci/psci_checker.c b/drivers/firmware/psci/psci_checker.c
index 3d6ba425dbb9..9a369a2eda71 100644
--- a/drivers/firmware/psci/psci_checker.c
+++ b/drivers/firmware/psci/psci_checker.c
@@ -274,7 +274,6 @@ static int suspend_test_thread(void *arg)
 {
 	int cpu = (long)arg;
 	int i, nb_suspend = 0, nb_shallow_sleep = 0, nb_err = 0;
-	struct sched_param sched_priority = { .sched_priority = MAX_RT_PRIO-1 };
 	struct cpuidle_device *dev;
 	struct cpuidle_driver *drv;
 	/* No need for an actual callback, we just want to wake up the CPU. */
@@ -284,9 +283,7 @@ static int suspend_test_thread(void *arg)
 	wait_for_completion(&suspend_threads_started);
 
 	/* Set maximum priority to preempt all other threads on this CPU. */
-	if (sched_setscheduler_nocheck(current, SCHED_FIFO, &sched_priority))
-		pr_warn("Failed to set suspend thread scheduler on CPU %d\n",
-			cpu);
+	sched_set_fifo(current);
 
 	dev = this_cpu_read(cpuidle_devices);
 	drv = cpuidle_get_cpu_driver(dev);
@@ -351,11 +348,6 @@ static int suspend_test_thread(void *arg)
 	if (atomic_dec_return_relaxed(&nb_active_threads) == 0)
 		complete(&suspend_threads_done);
 
-	/* Give up on RT scheduling and wait for termination. */
-	sched_priority.sched_priority = 0;
-	if (sched_setscheduler_nocheck(current, SCHED_NORMAL, &sched_priority))
-		pr_warn("Failed to set suspend thread scheduler on CPU %d\n",
-			cpu);
 	for (;;) {
 		/* Needs to be set first to avoid missing a wakeup. */
 		set_current_state(TASK_INTERRUPTIBLE);
diff --git a/drivers/gpu/drm/drm_vblank_work.c b/drivers/gpu/drm/drm_vblank_work.c
index 7ac0fc0a9415..bd481fdd6b87 100644
--- a/drivers/gpu/drm/drm_vblank_work.c
+++ b/drivers/gpu/drm/drm_vblank_work.c
@@ -248,9 +248,6 @@ EXPORT_SYMBOL(drm_vblank_work_init);
 
 int drm_vblank_worker_init(struct drm_vblank_crtc *vblank)
 {
-	struct sched_param param = {
-		.sched_priority = MAX_RT_PRIO - 1,
-	};
 	struct kthread_worker *worker;
 
 	INIT_LIST_HEAD(&vblank->pending_work);
@@ -263,5 +260,6 @@ int drm_vblank_worker_init(struct drm_vblank_crtc *vblank)
 
 	vblank->worker = worker;
 
-	return sched_setscheduler(vblank->worker->task, SCHED_FIFO, &param);
+	sched_set_fifo(worker->task);
+	return 0;
 }
diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
index 36d98d4116ca..7d641c7e3514 100644
--- a/drivers/gpu/drm/msm/msm_drv.c
+++ b/drivers/gpu/drm/msm/msm_drv.c
@@ -401,7 +401,6 @@ static int msm_drm_init(struct device *dev, struct drm_driver *drv)
 	struct msm_kms *kms;
 	struct msm_mdss *mdss;
 	int ret, i;
-	struct sched_param param;
 
 	ddev = drm_dev_alloc(drv, dev);
 	if (IS_ERR(ddev)) {
@@ -507,12 +506,6 @@ static int msm_drm_init(struct device *dev, struct drm_driver *drv)
 	ddev->mode_config.funcs = &mode_config_funcs;
 	ddev->mode_config.helper_private = &mode_config_helper_funcs;
 
-	/**
-	 * this priority was found during empiric testing to have appropriate
-	 * realtime scheduling to process display updates and interact with
-	 * other real time and normal priority task
-	 */
-	param.sched_priority = 16;
 	for (i = 0; i < priv->num_crtcs; i++) {
 		/* initialize event thread */
 		priv->event_thread[i].crtc_id = priv->crtcs[i]->base.id;
@@ -524,11 +517,7 @@ static int msm_drm_init(struct device *dev, struct drm_driver *drv)
 			goto err_msm_uninit;
 		}
 
-		ret = sched_setscheduler(priv->event_thread[i].worker->task,
-					 SCHED_FIFO, &param);
-		if (ret)
-			dev_warn(dev, "event_thread set priority failed:%d\n",
-				 ret);
+		sched_set_fifo(priv->event_thread[i].worker->task);
 	}
 
 	ret = drm_vblank_init(ddev, priv->num_crtcs);
diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c
index d6eaa23ad746..96f763d888af 100644
--- a/drivers/gpu/drm/scheduler/sched_main.c
+++ b/drivers/gpu/drm/scheduler/sched_main.c
@@ -762,11 +762,10 @@ static bool drm_sched_blocked(struct drm_gpu_scheduler *sched)
  */
 static int drm_sched_main(void *param)
 {
-	struct sched_param sparam = {.sched_priority = 1};
 	struct drm_gpu_scheduler *sched = (struct drm_gpu_scheduler *)param;
 	int r;
 
-	sched_setscheduler(current, SCHED_FIFO, &sparam);
+	sched_set_fifo_low(current);
 
 	while (!kthread_should_stop()) {
 		struct drm_sched_entity *entity = NULL;
diff --git a/drivers/media/pci/ivtv/ivtv-driver.c b/drivers/media/pci/ivtv/ivtv-driver.c
index b1dde1be6f5e..28acb14490d5 100644
--- a/drivers/media/pci/ivtv/ivtv-driver.c
+++ b/drivers/media/pci/ivtv/ivtv-driver.c
@@ -737,8 +737,6 @@ done:
  */
 static int ivtv_init_struct1(struct ivtv *itv)
 {
-	struct sched_param param = { .sched_priority = 99 };
-
 	itv->base_addr = pci_resource_start(itv->pdev, 0);
 	itv->enc_mbox.max_mbox = 2; /* the encoder has 3 mailboxes (0-2) */
 	itv->dec_mbox.max_mbox = 1; /* the decoder has 2 mailboxes (0-1) */
@@ -758,7 +756,7 @@ static int ivtv_init_struct1(struct ivtv *itv)
 		return -1;
 	}
 	/* must use the FIFO scheduler as it is realtime sensitive */
-	sched_setscheduler(itv->irq_worker_task, SCHED_FIFO, &param);
+	sched_set_fifo(itv->irq_worker_task);
 
 	kthread_init_work(&itv->irq_work, ivtv_irq_work_handler);
 
diff --git a/drivers/mmc/core/sdio_irq.c b/drivers/mmc/core/sdio_irq.c
index 3ffe4ff49aa7..4b1f7c966ec8 100644
--- a/drivers/mmc/core/sdio_irq.c
+++ b/drivers/mmc/core/sdio_irq.c
@@ -139,11 +139,10 @@ EXPORT_SYMBOL_GPL(sdio_signal_irq);
 static int sdio_irq_thread(void *_host)
 {
 	struct mmc_host *host = _host;
-	struct sched_param param = { .sched_priority = 1 };
 	unsigned long period, idle_period;
 	int ret;
 
-	sched_setscheduler(current, SCHED_FIFO, &param);
+	sched_set_fifo_low(current);
 
 	/*
 	 * We want to allow for SDIO cards to work even on non SDIO
diff --git a/drivers/platform/chrome/cros_ec_spi.c b/drivers/platform/chrome/cros_ec_spi.c
index debea5c4c829..d09260382550 100644
--- a/drivers/platform/chrome/cros_ec_spi.c
+++ b/drivers/platform/chrome/cros_ec_spi.c
@@ -709,9 +709,6 @@ static void cros_ec_spi_high_pri_release(void *worker)
 static int cros_ec_spi_devm_high_pri_alloc(struct device *dev,
 					   struct cros_ec_spi *ec_spi)
 {
-	struct sched_param sched_priority = {
-		.sched_priority = MAX_RT_PRIO / 2,
-	};
 	int err;
 
 	ec_spi->high_pri_worker =
@@ -728,11 +725,9 @@ static int cros_ec_spi_devm_high_pri_alloc(struct device *dev,
 	if (err)
 		return err;
 
-	err = sched_setscheduler_nocheck(ec_spi->high_pri_worker->task,
-					 SCHED_FIFO, &sched_priority);
-	if (err)
-		dev_err(dev, "Can't set cros_ec high pri priority: %d\n", err);
-	return err;
+	sched_set_fifo(ec_spi->high_pri_worker->task);
+
+	return 0;
 }
 
 static int cros_ec_spi_probe(struct spi_device *spi)
diff --git a/drivers/powercap/idle_inject.c b/drivers/powercap/idle_inject.c
index 597733ed86e9..4310901a074e 100644
--- a/drivers/powercap/idle_inject.c
+++ b/drivers/powercap/idle_inject.c
@@ -268,9 +268,7 @@ void idle_inject_stop(struct idle_inject_device *ii_dev)
  */
 static void idle_inject_setup(unsigned int cpu)
 {
-	struct sched_param param = { .sched_priority = MAX_USER_RT_PRIO / 2 };
-
-	sched_setscheduler(current, SCHED_FIFO, &param);
+	sched_set_fifo(current);
 }
 
 /**
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 0b260484b4f5..6626587e77b4 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -1626,11 +1626,9 @@ EXPORT_SYMBOL_GPL(spi_take_timestamp_post);
  */
 static void spi_set_thread_rt(struct spi_controller *ctlr)
 {
-	struct sched_param param = { .sched_priority = MAX_RT_PRIO / 2 };
-
 	dev_info(&ctlr->dev,
 		"will run message pump with realtime priority\n");
-	sched_setscheduler(ctlr->kworker->task, SCHED_FIFO, &param);
+	sched_set_fifo(ctlr->kworker->task);
 }
 
 static int spi_init_queue(struct spi_controller *ctlr)
diff --git a/drivers/staging/android/ion/ion_heap.c b/drivers/staging/android/ion/ion_heap.c
index 0755b11348ed..563b84cda2f0 100644
--- a/drivers/staging/android/ion/ion_heap.c
+++ b/drivers/staging/android/ion/ion_heap.c
@@ -244,8 +244,6 @@ static int ion_heap_deferred_free(void *data)
 
 int ion_heap_init_deferred_free(struct ion_heap *heap)
 {
-	struct sched_param param = { .sched_priority = 0 };
-
 	INIT_LIST_HEAD(&heap->free_list);
 	init_waitqueue_head(&heap->waitqueue);
 	heap->task = kthread_run(ion_heap_deferred_free, heap,
@@ -255,7 +253,7 @@ int ion_heap_init_deferred_free(struct ion_heap *heap)
 		       __func__);
 		return PTR_ERR_OR_ZERO(heap->task);
 	}
-	sched_setscheduler(heap->task, SCHED_IDLE, &param);
+	sched_set_normal(heap->task, 19);
 
 	return 0;
 }
diff --git a/drivers/thermal/intel/intel_powerclamp.c b/drivers/thermal/intel/intel_powerclamp.c
index f74b2473440d..b0eb5ece9243 100644
--- a/drivers/thermal/intel/intel_powerclamp.c
+++ b/drivers/thermal/intel/intel_powerclamp.c
@@ -70,9 +70,6 @@ static unsigned int control_cpu; /* The cpu assigned to collect stat and update
 				  */
 static bool clamping;
 
-static const struct sched_param sparam = {
-	.sched_priority = MAX_USER_RT_PRIO / 2,
-};
 struct powerclamp_worker_data {
 	struct kthread_worker *worker;
 	struct kthread_work balancing_work;
@@ -488,7 +485,7 @@ static void start_power_clamp_worker(unsigned long cpu)
 	w_data->cpu = cpu;
 	w_data->clamping = true;
 	set_bit(cpu, cpu_clamping_mask);
-	sched_setscheduler(worker->task, SCHED_FIFO, &sparam);
+	sched_set_fifo(worker->task);
 	kthread_init_work(&w_data->balancing_work, clamp_balancing_func);
 	kthread_init_delayed_work(&w_data->idle_injection_work,
 				  clamp_idle_injection_func);
diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
index d2e5c6c86643..809610b37c71 100644
--- a/drivers/tty/serial/sc16is7xx.c
+++ b/drivers/tty/serial/sc16is7xx.c
@@ -1179,7 +1179,6 @@ static int sc16is7xx_probe(struct device *dev,
 			   const struct sc16is7xx_devtype *devtype,
 			   struct regmap *regmap, int irq)
 {
-	struct sched_param sched_param = { .sched_priority = MAX_RT_PRIO / 2 };
 	unsigned long freq = 0, *pfreq = dev_get_platdata(dev);
 	unsigned int val;
 	u32 uartclk = 0;
@@ -1239,7 +1238,7 @@ static int sc16is7xx_probe(struct device *dev,
 		ret = PTR_ERR(s->kworker_task);
 		goto out_clk;
 	}
-	sched_setscheduler(s->kworker_task, SCHED_FIFO, &sched_param);
+	sched_set_fifo(s->kworker_task);
 
 #ifdef CONFIG_GPIOLIB
 	if (devtype->nr_gpio) {
diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c
index 7e4cd34a8c20..b9dc2c352151 100644
--- a/drivers/watchdog/watchdog_dev.c
+++ b/drivers/watchdog/watchdog_dev.c
@@ -1144,14 +1144,13 @@ void watchdog_dev_unregister(struct watchdog_device *wdd)
 int __init watchdog_dev_init(void)
 {
 	int err;
-	struct sched_param param = {.sched_priority = MAX_RT_PRIO - 1,};
 
 	watchdog_kworker = kthread_create_worker(0, "watchdogd");
 	if (IS_ERR(watchdog_kworker)) {
 		pr_err("Failed to create watchdog kworker\n");
 		return PTR_ERR(watchdog_kworker);
 	}
-	sched_setscheduler(watchdog_kworker->task, SCHED_FIFO, &param);
+	sched_set_fifo(watchdog_kworker->task);
 
 	err = class_register(&watchdog_class);
 	if (err < 0) {