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path: root/drivers/char/hvc_xen.c
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2009-11-03xen/hvc: make sure console output is always emitted, with explicit pollingJeremy Fitzhardinge
We never want to rely on the hvc workqueue to emit output, because the most interesting output is when the kernel is broken. This will improve oops/crash/console message for better debugging. Instead, we force-poll until all output is emitted. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Stable Kernel <stable@kernel.org>
2008-10-22hvc_console: Add a hangup notifier for backendsHendrik Brueckner
I have added a hangup notifier that can be used by hvc console backends to handle a tty hangup. The default irq hangup notifier calls the notifier_del_irq() for compatibility. Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2008-08-20xen: clean up domain mode predicatesJeremy Fitzhardinge
There are four operating modes Xen code may find itself running in: - native - hvm domain - pv dom0 - pv domU Clean up predicates for testing for these states to make them more consistent. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Xen-devel <xen-devel@lists.xensource.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-25hvc_console: rework setup to replace irq functions with callbacksChristian Borntraeger
This patch tries to change hvc_console to not use request_irq/free_irq if the backend does not use irqs. This allows virtio_console to use hvc_console without having a linker reference to request_irq/free_irq. In addition, together with patch 2/3 it improves the performance for virtio console input. (an earlier version of this patch was tested by Yajin on lguest) The irq specific code is moved to hvc_irq.c and selected by the drivers that use irqs (System p, System i, XEN). I replaced "int irq" with the opaque "int data". The request_irq and free_irq calls are replaced with notifier_add and notifier_del. I have also changed the code a bit to call the notifier_add and notifier_del inside the spinlock area as the callbacks are found via hp->ops. Changes since last version: o remove ifdef o reintroduce "irq_requested" as "notified" o cleanups, sparse.. I did not move the timer based polling into a separate polling scheme. I played with several variants, but it seems we need to sleep/schedule in a thread even for irq based consoles, as there are throttleing and buffer size constraints. I also kept hvc_struct defined in hvc_console.h so that hvc_irq.c can access the irq_requested element. Feedback is appreciated. virtio_console is currently the only available console for kvm on s390. I plan to push this change as soon as all affected parties agree on it. I would love to get test results from System p, Xen etc. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-05-27xen-console: add save/restoreJeremy Fitzhardinge
Add code to: 1. Deal with the console page being canonicalized. During save, the console's mfn in the start_info structure is canonicalized to a pfn. In order to deal with that, we always use a copy of the pfn and indirect off that all the time. However, we fall back to using the mfn if the pfn hasn't been initialized yet. 2. Restore the console event channel, and rebind it to the existing irq. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-27xen: make earlyprintk=xen work againJeremy Fitzhardinge
For some perverse reason, if you call add_preferred_console() it prevents setup_early_printk() from successfully enabling the boot console - unless you make it a preferred console too... Also, make xenboot console output distinct from normal console output, since it gets repeated when the console handover happens, and the duplicated output is confusing without disambiguation. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Markus Armbruster <armbru@redhat.com> Cc: Gerd Hoffmann <kraxel@redhat.com>
2008-05-27xen: make early console also write to debug consoleJeremy Fitzhardinge
When using "earlyprintk=xen", also write the console output to the raw debug console. This will appear on dom0's console if the hypervisor has been compiled to allow it. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-27xen: add raw console write functions for debugJeremy Fitzhardinge
Add a couple of functions which can write directly to the Xen console for debugging. This output ends up on the host's dom0 console (assuming it allows the domain to write there). Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2007-07-18xen: use the hvc console infrastructure for Xen consoleJeremy Fitzhardinge
Implement a Xen back-end for hvc console. * * * Add early printk support via hvc console, enable using "earlyprintk=xen" on the kernel command line. From: Gerd Hoffmann <kraxel@suse.de> Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Chris Wright <chrisw@sous-sol.org> Acked-by: Ingo Molnar <mingo@elte.hu> Acked-by: Olof Johansson <olof@lixom.net>