linux-toradex.git/drivers/tty/hvc, branch v3.14.57

xen/events: don't bind non-percpu VIRQs with percpu chip

2015-06-06T15:19:32+00:00

commit 77bb3dfdc0d554befad58fdefbc41be5bc3ed38a upstream.

A non-percpu VIRQ (e.g., VIRQ_CONSOLE) may be freed on a different
VCPU than it is bound to.  This can result in a race between
handle_percpu_irq() and removing the action in __free_irq() because
handle_percpu_irq() does not take desc->lock.  The interrupt handler
sees a NULL action and oopses.

Only use the percpu chip/handler for per-CPU VIRQs (like VIRQ_TIMER).

  # cat /proc/interrupts | grep virq
   40:      87246          0  xen-percpu-virq      timer0
   44:          0          0  xen-percpu-virq      debug0
   47:          0      20995  xen-percpu-virq      timer1
   51:          0          0  xen-percpu-virq      debug1
   69:          0          0   xen-dyn-virq      xen-pcpu
   74:          0          0   xen-dyn-virq      mce
   75:         29          0   xen-dyn-virq      hvc_console

Signed-off-by: David Vrabel 
Signed-off-by: Greg Kroah-Hartman

xen/console: Update console event channel on resume

2015-05-17T16:53:49+00:00

commit b9d934f27c91b878c4b2e64299d6e419a4022f8d upstream.

After a resume the hypervisor/tools may change console event
channel number. We should re-query it.

Signed-off-by: Boris Ostrovsky 
Signed-off-by: David Vrabel 
Signed-off-by: Greg Kroah-Hartman

drivers/tty/hvc: don't free hvc_console_setup after init

2014-05-13T11:32:46+00:00

commit 501fed45b7e8836ee9373f4d31e2d85e3db6103a upstream.

When 'console=hvc0' is specified to the kernel parameter in x86 KVM guest,
hvc console is setup within a kthread. However, that will cause SEGV
and the boot will fail when the driver is builtin to the kernel,
because currently hvc_console_setup() is annotated with '__init'. This
patch removes '__init' to boot the guest successfully with 'console=hvc0'.

Signed-off-by: Tomoki Sekiyama 
Signed-off-by: Greg Kroah-Hartman

hvc: ensure hvc_init is only ever called once in hvc_console.c

2014-05-06T14:59:33+00:00

commit f76a1cbed18c86e2d192455f0daebb48458965f3 upstream.

Commit 3e6c6f630a5282df8f3393a59f10eb9c56536d23 ("Delay creation of
khcvd thread") moved the call of hvc_init from being a device_initcall
into hvc_alloc, and used a non-null hvc_driver as indication of whether
hvc_init had already been called.

The problem with this is that hvc_driver is only assigned a value
at the bottom of hvc_init, and so there is a window where multiple
hvc_alloc calls can be in progress at the same time and hence try
and call hvc_init multiple times.  Previously the use of device_init
guaranteed that hvc_init was only called once.

This manifests itself as sporadic instances of two hvc_init calls
racing each other, and with the loser of the race getting -EBUSY
from tty_register_driver() and hence that virtual console fails:

    Couldn't register hvc console driver
    virtio-ports vport0p1: error -16 allocating hvc for port

Here we add an atomic_t to guarantee we'll never run hvc_init twice.

Cc: Rusty Russell 
Cc: Greg Kroah-Hartman 
Fixes: 3e6c6f630a52 ("Delay creation of khcvd thread")
Reported-by: Jim Somerville 
Tested-by: Jim Somerville 
Signed-off-by: Paul Gortmaker 
Signed-off-by: Greg Kroah-Hartman

drivers/tty/hvc: don't use module_init in non-modular hyp. console code

2014-02-07T16:40:54+00:00

The HVC_OPAL/RTAS/UDBG/XEN options are all bool, and hence their support
is either present or absent.  It will never be modular, so using
module_init as an alias for __initcall is rather misleading.

Fix this up now, so that we can relocate module_init from
init.h into module.h in the future.  If we don't do this, we'd
have to add module.h to obviously non-modular code, and that
would be a worse thing.

Note that direct use of __initcall is discouraged, vs. one
of the priority categorized subgroups.  As __initcall gets
mapped onto device_initcall, our use of device_initcall
directly in this change means that the runtime impact is
zero -- it will remain at level 6 in initcall ordering.

Also the __exitcall functions have been outright deleted since
they are only ever of interest to UML, and UML will never be
using any of this code.

Cc: Richard Weinberger 
Cc: Konrad Rzeszutek Wilk 
Cc: Boris Ostrovsky 
Signed-off-by: Paul Gortmaker 
Acked-by: David Vrabel 
Signed-off-by: Greg Kroah-Hartman

s390/hvc_iucv: Automatically assign free HVC terminal devices

2014-01-22T13:02:13+00:00

Add the generic "lnxhvc" terminal ID to automatically assign a HVC terminal when
connecting to the HVC IUCV terminal device driver.  The terminal device driver
tries to find a free (not connected) HVC terminal to satisfy the incoming
connection request.

With this improvement, you do not longer need to guess which HVC terminal is
free, that is, not connected.  Also you can still connect to a particular HVC
terminal by using its associated terminal ID.

Signed-off-by: Hendrik Brueckner 
Signed-off-by: Martin Schwidefsky

s390/hvc_iucv: Display connection details through device attributes

2014-01-22T13:02:13+00:00

Add device attributes to display details about the connection status
of HVC IUCV terminals.

Signed-off-by: Hendrik Brueckner 
Signed-off-by: Martin Schwidefsky

s390/hvc_iucv: fix sparse warning

2014-01-22T13:02:12+00:00

drivers/tty/hvc/hvc_iucv.c:131:25: warning: symbol 'hvc_iucv_get_private' was not
declared. Should it be static?

Signed-off-by: Hendrik Brueckner 
Signed-off-by: Martin Schwidefsky

tty: delete non-required instances of include

2014-01-08T01:05:21+00:00

None of these files are actually using any __init type directives
and hence don't need to include .  Most are just a
left over from __devinit and __cpuinit removal, or simply due to
code getting copied from one driver to the next.

Signed-off-by: Paul Gortmaker 
Signed-off-by: Greg Kroah-Hartman

drivers: tty: Mark the function hvc_poll_init() as static in hvc_console.c

2013-12-17T17:37:44+00:00

Mark the function hvc_poll_init() as static in hvc/hvc_console.c because
it is not used outside this file.

This eliminates the following warning in hvc/hvc_console.c:
drivers/tty/hvc/hvc_console.c:791:5: warning: no previous prototype for ‘hvc_poll_init’ [-Wmissing-prototypes]

Signed-off-by: Rashika Kheria 
Reviewed-by: Josh Triplett 
Signed-off-by: Greg Kroah-Hartman