[GIT PULL] s390 patches for 3.3-rc4

From: Martin Schwidefsky
Date: Mon Feb 20 2012 - 04:38:24 EST


Hi Linus,

please pull from 'for-linus' branch of

git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux.git for-linus

to receive the following updates:

Heiko Carstens (1):
[S390] idle: avoid RCU usage in extended quiescent state

Martin Schwidefsky (3):
[S390] incorrect PageTables counter for kvm page tables
[S390] 3215 deadlock with tty_wakeup
[S390] correct ktime to tod clock comparator conversion

arch/s390/kernel/process.c | 5 +++--
arch/s390/kernel/time.c | 7 +++++--
arch/s390/mm/pgtable.c | 2 +-
drivers/s390/char/con3215.c | 22 +++++++++++++++-------
4 files changed, 24 insertions(+), 12 deletions(-)

diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c
index 3201ae4..4261aa7 100644
--- a/arch/s390/kernel/process.c
+++ b/arch/s390/kernel/process.c
@@ -76,7 +76,6 @@ static void default_idle(void)
if (test_thread_flag(TIF_MCCK_PENDING)) {
local_mcck_enable();
local_irq_enable();
- s390_handle_mcck();
return;
}
trace_hardirqs_on();
@@ -93,10 +92,12 @@ void cpu_idle(void)
for (;;) {
tick_nohz_idle_enter();
rcu_idle_enter();
- while (!need_resched())
+ while (!need_resched() && !test_thread_flag(TIF_MCCK_PENDING))
default_idle();
rcu_idle_exit();
tick_nohz_idle_exit();
+ if (test_thread_flag(TIF_MCCK_PENDING))
+ s390_handle_mcck();
preempt_enable_no_resched();
schedule();
preempt_disable();
diff --git a/arch/s390/kernel/time.c b/arch/s390/kernel/time.c
index fa02f44..14da278 100644
--- a/arch/s390/kernel/time.c
+++ b/arch/s390/kernel/time.c
@@ -113,11 +113,14 @@ static void fixup_clock_comparator(unsigned long long delta)
static int s390_next_ktime(ktime_t expires,
struct clock_event_device *evt)
{
+ struct timespec ts;
u64 nsecs;

- nsecs = ktime_to_ns(ktime_sub(expires, ktime_get_monotonic_offset()));
+ ts.tv_sec = ts.tv_nsec = 0;
+ monotonic_to_bootbased(&ts);
+ nsecs = ktime_to_ns(ktime_add(timespec_to_ktime(ts), expires));
do_div(nsecs, 125);
- S390_lowcore.clock_comparator = TOD_UNIX_EPOCH + (nsecs << 9);
+ S390_lowcore.clock_comparator = sched_clock_base_cc + (nsecs << 9);
set_clock_comparator(S390_lowcore.clock_comparator);
return 0;
}
diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c
index 9a4d02f..51b0738 100644
--- a/arch/s390/mm/pgtable.c
+++ b/arch/s390/mm/pgtable.c
@@ -574,7 +574,7 @@ static inline void page_table_free_pgste(unsigned long *table)
page = pfn_to_page(__pa(table) >> PAGE_SHIFT);
mp = (struct gmap_pgtable *) page->index;
BUG_ON(!list_empty(&mp->mapper));
- pgtable_page_ctor(page);
+ pgtable_page_dtor(page);
atomic_set(&page->_mapcount, -1);
kfree(mp);
__free_page(page);
diff --git a/drivers/s390/char/con3215.c b/drivers/s390/char/con3215.c
index 934458a..e71a50d 100644
--- a/drivers/s390/char/con3215.c
+++ b/drivers/s390/char/con3215.c
@@ -87,6 +87,7 @@ struct raw3215_info {
struct tty_struct *tty; /* pointer to tty structure if present */
struct raw3215_req *queued_read; /* pointer to queued read requests */
struct raw3215_req *queued_write;/* pointer to queued write requests */
+ struct tasklet_struct tlet; /* tasklet to invoke tty_wakeup */
wait_queue_head_t empty_wait; /* wait queue for flushing */
struct timer_list timer; /* timer for delayed output */
int line_pos; /* position on the line (for tabs) */
@@ -334,19 +335,23 @@ static inline void raw3215_try_io(struct raw3215_info *raw)
}

/*
+ * Call tty_wakeup from tasklet context
+ */
+static void raw3215_wakeup(unsigned long data)
+{
+ struct raw3215_info *raw = (struct raw3215_info *) data;
+ tty_wakeup(raw->tty);
+}
+
+/*
* Try to start the next IO and wake up processes waiting on the tty.
*/
static void raw3215_next_io(struct raw3215_info *raw)
{
- struct tty_struct *tty;
-
raw3215_mk_write_req(raw);
raw3215_try_io(raw);
- tty = raw->tty;
- if (tty != NULL &&
- RAW3215_BUFFER_SIZE - raw->count >= RAW3215_MIN_SPACE) {
- tty_wakeup(tty);
- }
+ if (raw->tty && RAW3215_BUFFER_SIZE - raw->count >= RAW3215_MIN_SPACE)
+ tasklet_schedule(&raw->tlet);
}

/*
@@ -682,6 +687,7 @@ static int raw3215_probe (struct ccw_device *cdev)
return -ENOMEM;
}
init_waitqueue_head(&raw->empty_wait);
+ tasklet_init(&raw->tlet, raw3215_wakeup, (unsigned long) raw);

dev_set_drvdata(&cdev->dev, raw);
cdev->handler = raw3215_irq;
@@ -901,6 +907,7 @@ static int __init con3215_init(void)

raw->flags |= RAW3215_FIXED;
init_waitqueue_head(&raw->empty_wait);
+ tasklet_init(&raw->tlet, raw3215_wakeup, (unsigned long) raw);

/* Request the console irq */
if (raw3215_startup(raw) != 0) {
@@ -966,6 +973,7 @@ static void tty3215_close(struct tty_struct *tty, struct file * filp)
tty->closing = 1;
/* Shutdown the terminal */
raw3215_shutdown(raw);
+ tasklet_kill(&raw->tlet);
tty->closing = 0;
raw->tty = NULL;
}

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