diff options
| -rw-r--r-- | arch/s390/include/asm/lowcore.h | 4 | ||||
| -rw-r--r-- | arch/s390/include/asm/processor.h | 1 | ||||
| -rw-r--r-- | arch/s390/kernel/asm-offsets.c | 1 | ||||
| -rw-r--r-- | arch/s390/kernel/entry.S | 1 | ||||
| -rw-r--r-- | arch/s390/kernel/entry64.S | 1 | ||||
| -rw-r--r-- | arch/s390/mm/fault.c | 89 |
6 files changed, 71 insertions, 26 deletions
diff --git a/arch/s390/include/asm/lowcore.h b/arch/s390/include/asm/lowcore.h index b8624d53c37..228cf0b295d 100644 --- a/arch/s390/include/asm/lowcore.h +++ b/arch/s390/include/asm/lowcore.h @@ -124,7 +124,7 @@ struct _lowcore { /* Address space pointer. */ __u32 kernel_asce; /* 0x02ac */ __u32 user_asce; /* 0x02b0 */ - __u8 pad_0x02b4[0x02b8-0x02b4]; /* 0x02b4 */ + __u32 current_pid; /* 0x02b4 */ /* SMP info area */ __u32 cpu_nr; /* 0x02b8 */ @@ -255,7 +255,7 @@ struct _lowcore { /* Address space pointer. */ __u64 kernel_asce; /* 0x0310 */ __u64 user_asce; /* 0x0318 */ - __u8 pad_0x0320[0x0328-0x0320]; /* 0x0320 */ + __u64 current_pid; /* 0x0320 */ /* SMP info area */ __u32 cpu_nr; /* 0x0328 */ diff --git a/arch/s390/include/asm/processor.h b/arch/s390/include/asm/processor.h index 2c79b641627..1300c302533 100644 --- a/arch/s390/include/asm/processor.h +++ b/arch/s390/include/asm/processor.h @@ -84,6 +84,7 @@ struct thread_struct { struct per_event per_event; /* Cause of the last PER trap */ /* pfault_wait is used to block the process on a pfault event */ unsigned long pfault_wait; + struct list_head list; }; typedef struct thread_struct thread_struct; diff --git a/arch/s390/kernel/asm-offsets.c b/arch/s390/kernel/asm-offsets.c index ef455561101..edfbd17d708 100644 --- a/arch/s390/kernel/asm-offsets.c +++ b/arch/s390/kernel/asm-offsets.c @@ -124,6 +124,7 @@ int main(void) DEFINE(__LC_LAST_UPDATE_TIMER, offsetof(struct _lowcore, last_update_timer)); DEFINE(__LC_LAST_UPDATE_CLOCK, offsetof(struct _lowcore, last_update_clock)); DEFINE(__LC_CURRENT, offsetof(struct _lowcore, current_task)); + DEFINE(__LC_CURRENT_PID, offsetof(struct _lowcore, current_pid)); DEFINE(__LC_THREAD_INFO, offsetof(struct _lowcore, thread_info)); DEFINE(__LC_KERNEL_STACK, offsetof(struct _lowcore, kernel_stack)); DEFINE(__LC_ASYNC_STACK, offsetof(struct _lowcore, async_stack)); diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S index 1b67fc6ebdc..0476174dfff 100644 --- a/arch/s390/kernel/entry.S +++ b/arch/s390/kernel/entry.S @@ -212,6 +212,7 @@ __switch_to: lctl %c4,%c4,__TASK_pid(%r3) # load pid to control reg. 4 lm %r6,%r15,__SF_GPRS(%r15) # load gprs of next task st %r3,__LC_CURRENT # store task struct of next + mvc __LC_CURRENT_PID(4,%r0),__TASK_pid(%r3) # store pid of next st %r5,__LC_THREAD_INFO # store thread info of next ahi %r5,STACK_SIZE # end of kernel stack of next st %r5,__LC_KERNEL_STACK # store end of kernel stack diff --git a/arch/s390/kernel/entry64.S b/arch/s390/kernel/entry64.S index 9fd86456349..d61967e2eab 100644 --- a/arch/s390/kernel/entry64.S +++ b/arch/s390/kernel/entry64.S @@ -220,6 +220,7 @@ __switch_to: lctl %c4,%c4,__TASK_pid(%r3) # load pid to control reg. 4 lmg %r6,%r15,__SF_GPRS(%r15) # load gprs of next task stg %r3,__LC_CURRENT # store task struct of next + mvc __LC_CURRENT_PID+4(4,%r0),__TASK_pid(%r3) # store pid of next stg %r5,__LC_THREAD_INFO # store thread info of next aghi %r5,STACK_SIZE # end of kernel stack of next stg %r5,__LC_KERNEL_STACK # store end of kernel stack diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c index 177745c520c..1ca65647832 100644 --- a/arch/s390/mm/fault.c +++ b/arch/s390/mm/fault.c @@ -466,7 +466,7 @@ typedef struct { 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; @@ -498,11 +498,15 @@ void pfault_fini(void) : : "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 @@ -514,44 +518,79 @@ static void pfault_interrupt(unsigned int ext_int_code, 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) @@ -568,8 +607,10 @@ 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; |