From 611e097d7707741a336a0677d9d69bec40f29f3d Mon Sep 17 00:00:00 2001 From: Christian Borntraeger Date: Fri, 20 Jun 2008 15:24:08 +0200 Subject: hvc_console: rework setup to replace irq functions with callbacks 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 Signed-off-by: Rusty Russell --- drivers/char/Kconfig | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'drivers/char/Kconfig') diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig index 67b07576f8b..d825361a6ba 100644 --- a/drivers/char/Kconfig +++ b/drivers/char/Kconfig @@ -578,11 +578,14 @@ config HVC_DRIVER It will automatically be selected if one of the back-end console drivers is selected. +config HVC_IRQ + bool config HVC_CONSOLE bool "pSeries Hypervisor Virtual Console support" depends on PPC_PSERIES select HVC_DRIVER + select HVC_IRQ help pSeries machines when partitioned support a hypervisor virtual console. This driver allows each pSeries partition to have a console @@ -593,6 +596,7 @@ config HVC_ISERIES depends on PPC_ISERIES default y select HVC_DRIVER + select HVC_IRQ help iSeries machines support a hypervisor virtual console. @@ -614,6 +618,7 @@ config HVC_XEN bool "Xen Hypervisor Console support" depends on XEN select HVC_DRIVER + select HVC_IRQ default y help Xen virtual console device driver -- cgit v1.2.3-70-g09d2