int pfault_init(void)
{
pfault_refbk_t refbk =
- { 0x258, 0, 5, 2, __LC_CURRENT, 1ULL << 48, 1ULL << 48,
+ { 0x258, 0, 5, 2, __LC_CURRENT_PID, 1ULL << 48, 1ULL << 48,
__PF_RES_FIELD };
int rc;
: : "a" (&refbk), "m" (refbk) : "cc");
}
+static DEFINE_SPINLOCK(pfault_lock);
+static LIST_HEAD(pfault_list);
+
static void pfault_interrupt(unsigned int ext_int_code,
unsigned int param32, unsigned long param64)
{
struct task_struct *tsk;
__u16 subcode;
+ pid_t pid;
/*
* Get the external interruption subcode & pfault
if ((subcode & 0xff00) != __SUBCODE_MASK)
return;
kstat_cpu(smp_processor_id()).irqs[EXTINT_PFL]++;
-
- /*
- * Get the token (= address of the task structure of the affected task).
- */
-#ifdef CONFIG_64BIT
- tsk = (struct task_struct *) param64;
-#else
- tsk = (struct task_struct *) param32;
-#endif
-
+ if (subcode & 0x0080) {
+ /* Get the token (= pid of the affected task). */
+ pid = sizeof(void *) == 4 ? param32 : param64;
+ rcu_read_lock();
+ tsk = find_task_by_pid_ns(pid, &init_pid_ns);
+ if (tsk)
+ get_task_struct(tsk);
+ rcu_read_unlock();
+ if (!tsk)
+ return;
+ } else {
+ tsk = current;
+ }
+ spin_lock(&pfault_lock);
if (subcode & 0x0080) {
/* signal bit is set -> a page has been swapped in by VM */
- if (xchg(&tsk->thread.pfault_wait, -1) != 0) {
+ if (tsk->thread.pfault_wait == 1) {
/* Initial interrupt was faster than the completion
* interrupt. pfault_wait is valid. Set pfault_wait
* back to zero and wake up the process. This can
* safely be done because the task is still sleeping
* and can't produce new pfaults. */
tsk->thread.pfault_wait = 0;
+ list_del(&tsk->thread.list);
wake_up_process(tsk);
- put_task_struct(tsk);
+ } else {
+ /* Completion interrupt was faster than initial
+ * interrupt. Set pfault_wait to -1 so the initial
+ * interrupt doesn't put the task to sleep. */
+ tsk->thread.pfault_wait = -1;
}
+ put_task_struct(tsk);
} else {
/* signal bit not set -> a real page is missing. */
- get_task_struct(tsk);
- set_task_state(tsk, TASK_UNINTERRUPTIBLE);
- if (xchg(&tsk->thread.pfault_wait, 1) != 0) {
+ if (tsk->thread.pfault_wait == -1) {
/* Completion interrupt was faster than the initial
- * interrupt (swapped in a -1 for pfault_wait). Set
- * pfault_wait back to zero and exit. This can be
- * done safely because tsk is running in kernel
- * mode and can't produce new pfaults. */
+ * interrupt (pfault_wait == -1). Set pfault_wait
+ * back to zero and exit. */
tsk->thread.pfault_wait = 0;
- set_task_state(tsk, TASK_RUNNING);
- put_task_struct(tsk);
- } else
+ } else {
+ /* Initial interrupt arrived before completion
+ * interrupt. Let the task sleep. */
+ tsk->thread.pfault_wait = 1;
+ list_add(&tsk->thread.list, &pfault_list);
+ set_task_state(tsk, TASK_UNINTERRUPTIBLE);
set_tsk_need_resched(tsk);
+ }
+ }
+ spin_unlock(&pfault_lock);
+}
+
+static int __cpuinit pfault_cpu_notify(struct notifier_block *self,
+ unsigned long action, void *hcpu)
+{
+ struct thread_struct *thread, *next;
+ struct task_struct *tsk;
+
+ switch (action) {
+ case CPU_DEAD:
+ case CPU_DEAD_FROZEN:
+ spin_lock_irq(&pfault_lock);
+ list_for_each_entry_safe(thread, next, &pfault_list, list) {
+ thread->pfault_wait = 0;
+ list_del(&thread->list);
+ tsk = container_of(thread, struct task_struct, thread);
+ wake_up_process(tsk);
+ }
+ spin_unlock_irq(&pfault_lock);
+ break;
+ default:
+ break;
}
+ return NOTIFY_OK;
}
static int __init pfault_irq_init(void)
pfault_disable = 1;
return rc;
}
- if (pfault_init() == 0)
+ if (pfault_init() == 0) {
+ hotcpu_notifier(pfault_cpu_notify, 0);
return 0;
+ }
/* Tough luck, no pfault. */
pfault_disable = 1;
projects / GitHub / LineageOS / android_kernel_samsung_universal7580.git / commitdiff