Merge android-4.4.115 (aa856bd) into msm-4.4

* refs/heads/tmp-aa856bd
  Linux 4.4.115
  spi: imx: do not access registers while clocks disabled
  serial: imx: Only wakeup via RTSDEN bit if the system has RTS/CTS
  selinux: general protection fault in sock_has_perm
  usb: uas: unconditionally bring back host after reset
  usb: f_fs: Prevent gadget unbind if it is already unbound
  USB: serial: simple: add Motorola Tetra driver
  usbip: list: don't list devices attached to vhci_hcd
  usbip: prevent bind loops on devices attached to vhci_hcd
  USB: serial: io_edgeport: fix possible sleep-in-atomic
  CDC-ACM: apply quirk for card reader
  USB: cdc-acm: Do not log urb submission errors on disconnect
  USB: serial: pl2303: new device id for Chilitag
  usb: option: Add support for FS040U modem
  staging: rtl8188eu: Fix incorrect response to SIOCGIWESSID
  usb: gadget: don't dereference g until after it has been null checked
  media: usbtv: add a new usbid
  scsi: ufs: ufshcd: fix potential NULL pointer dereference in ufshcd_config_vreg
  scsi: aacraid: Prevent crash in case of free interrupt during scsi EH path
  xfs: ubsan fixes
  drm/omap: Fix error handling path in 'omap_dmm_probe()'
  kmemleak: add scheduling point to kmemleak_scan()
  SUNRPC: Allow connect to return EHOSTUNREACH
  quota: Check for register_shrinker() failure.
  net: ethernet: xilinx: Mark XILINX_LL_TEMAC broken on 64-bit
  hwmon: (pmbus) Use 64bit math for DIRECT format values
  lockd: fix "list_add double add" caused by legacy signal interface
  nfsd: check for use of the closed special stateid
  grace: replace BUG_ON by WARN_ONCE in exit_net hook
  nfsd: Ensure we check stateid validity in the seqid operation checks
  nfsd: CLOSE SHOULD return the invalid special stateid for NFSv4.x (x>0)
  xen-netfront: remove warning when unloading module
  KVM: VMX: Fix rflags cache during vCPU reset
  btrfs: fix deadlock when writing out space cache
  mac80211: fix the update of path metric for RANN frame
  openvswitch: fix the incorrect flow action alloc size
  drm/amdkfd: Fix SDMA oversubsription handling
  drm/amdkfd: Fix SDMA ring buffer size calculation
  drm/amdgpu: Fix SDMA load/unload sequence on HWS disabled mode
  bcache: check return value of register_shrinker
  cpufreq: Add Loongson machine dependencies
  ACPI / bus: Leave modalias empty for devices which are not present
  KVM: x86: ioapic: Preserve read-only values in the redirection table
  KVM: x86: ioapic: Clear Remote IRR when entry is switched to edge-triggered
  KVM: x86: ioapic: Fix level-triggered EOI and IOAPIC reconfigure race
  KVM: X86: Fix operand/address-size during instruction decoding
  KVM: x86: Don't re-execute instruction when not passing CR2 value
  KVM: x86: emulator: Return to user-mode on L1 CPL=0 emulation failure
  igb: Free IRQs when device is hotplugged
  mtd: nand: denali_pci: add missing MODULE_DESCRIPTION/AUTHOR/LICENSE
  gpio: ath79: add missing MODULE_DESCRIPTION/LICENSE
  gpio: iop: add missing MODULE_DESCRIPTION/AUTHOR/LICENSE
  power: reset: zx-reboot: add missing MODULE_DESCRIPTION/AUTHOR/LICENSE
  crypto: af_alg - whitelist mask and type
  crypto: aesni - handle zero length dst buffer
  ALSA: seq: Make ioctls race-free
  kaiser: fix intel_bts perf crashes
  x86/pti: Make unpoison of pgd for trusted boot work for real
  bpf: reject stores into ctx via st and xadd
  bpf: fix 32-bit divide by zero
  bpf: fix divides by zero
  bpf: avoid false sharing of map refcount with max_entries
  bpf: arsh is not supported in 32 bit alu thus reject it
  bpf: introduce BPF_JIT_ALWAYS_ON config
  bpf: fix bpf_tail_call() x64 JIT
  x86: bpf_jit: small optimization in emit_bpf_tail_call()
  bpf: fix branch pruning logic
  loop: fix concurrent lo_open/lo_release
  ANDROID: sdcardfs: Protect set_top
  ANDROID: fsnotify: Notify lower fs of open
  Revert "ANDROID: sdcardfs: notify lower file of opens"
  ANDROID: sdcardfs: Use lower getattr times/size
  ANDROID: sched/rt: schedtune: Add boost retention to RT

Conflicts:
	arch/x86/Kconfig
	kernel/sched/rt.c

Change-Id: I91b08e1b8e0a1c6ca9c245597acad0bf197f9527
Signed-off-by: Srinivasarao P <spathi@codeaurora.org>

3 files changed, 150 insertions, 0 deletions

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 59ba1d1266a7..41a8fdb1436c 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -2368,6 +2368,7 @@ static void __sched_fork(unsigned long clone_flags, struct task_struct *p)
 	init_dl_task_timer(&p->dl);
 	__dl_clear_params(p);
 
+	init_rt_schedtune_timer(&p->rt);
 	INIT_LIST_HEAD(&p->rt.run_list);
 	p->rt.timeout		= 0;
 	p->rt.time_slice	= sched_rr_timeslice;
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index 8025828ff4e0..baad64b94f15 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -9,6 +9,7 @@
 #include <linux/slab.h>
 #include <linux/irq_work.h>
 #include <trace/events/sched.h>
+#include <linux/hrtimer.h>
 
 #include "tune.h"
 
@@ -980,6 +981,70 @@ static int sched_rt_runtime_exceeded(struct rt_rq *rt_rq)
 	return 0;
 }
 
+#define RT_SCHEDTUNE_INTERVAL 50000000ULL
+
+static enum hrtimer_restart rt_schedtune_timer(struct hrtimer *timer)
+{
+	struct sched_rt_entity *rt_se = container_of(timer,
+			struct sched_rt_entity,
+			schedtune_timer);
+	struct task_struct *p = rt_task_of(rt_se);
+	struct rq *rq = task_rq(p);
+
+	raw_spin_lock(&rq->lock);
+
+	/*
+	 * Nothing to do if:
+	 * - task has switched runqueues
+	 * - task isn't RT anymore
+	 */
+	if (rq != task_rq(p) || (p->sched_class != &rt_sched_class))
+		goto out;
+
+	/*
+	 * If task got enqueued back during callback time, it means we raced
+	 * with the enqueue on another cpu, that's Ok, just do nothing as
+	 * enqueue path would have tried to cancel us and we shouldn't run
+	 * Also check the schedtune_enqueued flag as class-switch on a
+	 * sleeping task may have already canceled the timer and done dq
+	 */
+	if (p->on_rq || !rt_se->schedtune_enqueued)
+		goto out;
+
+	/*
+	 * RT task is no longer active, cancel boost
+	 */
+	rt_se->schedtune_enqueued = false;
+	schedtune_dequeue_task(p, cpu_of(rq));
+	cpufreq_update_this_cpu(rq, SCHED_CPUFREQ_RT);
+out:
+	raw_spin_unlock(&rq->lock);
+
+	/*
+	 * This can free the task_struct if no more references.
+	 */
+	put_task_struct(p);
+
+	return HRTIMER_NORESTART;
+}
+
+void init_rt_schedtune_timer(struct sched_rt_entity *rt_se)
+{
+	struct hrtimer *timer = &rt_se->schedtune_timer;
+
+	hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+	timer->function = rt_schedtune_timer;
+	rt_se->schedtune_enqueued = false;
+}
+
+static void start_schedtune_timer(struct sched_rt_entity *rt_se)
+{
+	struct hrtimer *timer = &rt_se->schedtune_timer;
+
+	hrtimer_start(timer, ns_to_ktime(RT_SCHEDTUNE_INTERVAL),
+			HRTIMER_MODE_REL_PINNED);
+}
+
 /*
  * Update the current task's runtime statistics. Skip current tasks that
  * are not in our scheduling class.
@@ -1386,7 +1451,32 @@ enqueue_task_rt(struct rq *rq, struct task_struct *p, int flags)
 	if (!task_current(rq, p) && p->nr_cpus_allowed > 1)
 		enqueue_pushable_task(rq, p);
 
+	if (!schedtune_task_boost(p))
+		return;
+
+	/*
+	 * If schedtune timer is active, that means a boost was already
+	 * done, just cancel the timer so that deboost doesn't happen.
+	 * Otherwise, increase the boost. If an enqueued timer was
+	 * cancelled, put the task reference.
+	 */
+	if (hrtimer_try_to_cancel(&rt_se->schedtune_timer) == 1)
+		put_task_struct(p);
+
+	/*
+	 * schedtune_enqueued can be true in the following situation:
+	 * enqueue_task_rt grabs rq lock before timer fires
+	 *    or before its callback acquires rq lock
+	 * schedtune_enqueued can be false if timer callback is running
+	 * and timer just released rq lock, or if the timer finished
+	 * running and canceling the boost
+	 */
+	if (rt_se->schedtune_enqueued)
+		return;
+
+	rt_se->schedtune_enqueued = true;
 	schedtune_enqueue_task(p, cpu_of(rq));
+	cpufreq_update_this_cpu(rq, SCHED_CPUFREQ_RT);
 }
 
 static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int flags)
@@ -1398,7 +1488,19 @@ static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int flags)
 	dec_hmp_sched_stats_rt(rq, p);
 
 	dequeue_pushable_task(rq, p);
+
+	if (!rt_se->schedtune_enqueued)
+		return;
+
+	if (flags == DEQUEUE_SLEEP) {
+		get_task_struct(p);
+		start_schedtune_timer(rt_se);
+		return;
+	}
+
+	rt_se->schedtune_enqueued = false;
 	schedtune_dequeue_task(p, cpu_of(rq));
+	cpufreq_update_this_cpu(rq, SCHED_CPUFREQ_RT);
 }
 
 /*
@@ -1472,6 +1574,32 @@ task_may_not_preempt(struct task_struct *task, int cpu)
 		 task_thread_info(task)->preempt_count & SOFTIRQ_MASK));
 }
 
+/*
+ * Perform a schedtune dequeue and cancelation of boost timers if needed.
+ * Should be called only with the rq->lock held.
+ */
+static void schedtune_dequeue_rt(struct rq *rq, struct task_struct *p)
+{
+	struct sched_rt_entity *rt_se = &p->rt;
+
+	BUG_ON(!raw_spin_is_locked(&rq->lock));
+
+	if (!rt_se->schedtune_enqueued)
+		return;
+
+	/*
+	 * Incase of class change cancel any active timers. If an enqueued
+	 * timer was cancelled, put the task ref.
+	 */
+	if (hrtimer_try_to_cancel(&rt_se->schedtune_timer) == 1)
+		put_task_struct(p);
+
+	/* schedtune_enqueued is true, deboost it */
+	rt_se->schedtune_enqueued = false;
+	schedtune_dequeue_task(p, task_cpu(p));
+	cpufreq_update_this_cpu(rq, SCHED_CPUFREQ_RT);
+}
+
 static int
 select_task_rq_rt(struct task_struct *p, int cpu, int sd_flag, int flags,
 		  int sibling_count_hint)
@@ -1546,6 +1674,19 @@ select_task_rq_rt(struct task_struct *p, int cpu, int sd_flag, int flags,
 	rcu_read_unlock();
 
 out:
+	/*
+	 * If previous CPU was different, make sure to cancel any active
+	 * schedtune timers and deboost.
+	 */
+	if (task_cpu(p) != cpu) {
+		unsigned long fl;
+		struct rq *prq = task_rq(p);
+
+		raw_spin_lock_irqsave(&prq->lock, fl);
+		schedtune_dequeue_rt(prq, p);
+		raw_spin_unlock_irqrestore(&prq->lock, fl);
+	}
+
 	return cpu;
 }
 
@@ -2402,6 +2543,13 @@ static void rq_offline_rt(struct rq *rq)
 static void switched_from_rt(struct rq *rq, struct task_struct *p)
 {
 	/*
+	 * On class switch from rt, always cancel active schedtune timers,
+	 * this handles the cases where we switch class for a task that is
+	 * already rt-dequeued but has a running timer.
+	 */
+	schedtune_dequeue_rt(rq, p);
+
+	/*
 	 * If there are other RT tasks then we will reschedule
 	 * and the scheduling of the other RT tasks will handle
 	 * the balancing. But if we are the last RT task
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index ca2294d06f44..6ef3a59612a9 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -2199,6 +2199,7 @@ extern void resched_cpu(int cpu);
 
 extern struct rt_bandwidth def_rt_bandwidth;
 extern void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime);
+extern void init_rt_schedtune_timer(struct sched_rt_entity *rt_se);
 
 extern struct dl_bandwidth def_dl_bandwidth;
 extern void init_dl_bandwidth(struct dl_bandwidth *dl_b, u64 period, u64 runtime);