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/hvc_console.h | 35 +++++++++++++++++++++++++++++++---- 1 file changed, 31 insertions(+), 4 deletions(-) (limited to 'drivers/char/hvc_console.h') diff --git a/drivers/char/hvc_console.h b/drivers/char/hvc_console.h index 42ffb17e15d..d9ce1091562 100644 --- a/drivers/char/hvc_console.h +++ b/drivers/char/hvc_console.h @@ -26,6 +26,7 @@ #ifndef HVC_CONSOLE_H #define HVC_CONSOLE_H +#include /* * This is the max number of console adapters that can/will be found as @@ -42,24 +43,50 @@ */ #define HVC_ALLOC_TTY_ADAPTERS 8 +struct hvc_struct { + spinlock_t lock; + int index; + struct tty_struct *tty; + unsigned int count; + int do_wakeup; + char *outbuf; + int outbuf_size; + int n_outbuf; + uint32_t vtermno; + struct hv_ops *ops; + int irq_requested; + int data; + struct list_head next; + struct kref kref; /* ref count & hvc_struct lifetime */ +}; /* implemented by a low level driver */ struct hv_ops { int (*get_chars)(uint32_t vtermno, char *buf, int count); int (*put_chars)(uint32_t vtermno, const char *buf, int count); -}; -struct hvc_struct; + /* Callbacks for notification. Called in open and close */ + int (*notifier_add)(struct hvc_struct *hp, int irq); + void (*notifier_del)(struct hvc_struct *hp, int irq); +}; /* Register a vterm and a slot index for use as a console (console_init) */ extern int hvc_instantiate(uint32_t vtermno, int index, struct hv_ops *ops); /* register a vterm for hvc tty operation (module_init or hotplug add) */ -extern struct hvc_struct * __devinit hvc_alloc(uint32_t vtermno, int irq, +extern struct hvc_struct * __devinit hvc_alloc(uint32_t vtermno, int data, struct hv_ops *ops, int outbuf_size); -/* remove a vterm from hvc tty operation (modele_exit or hotplug remove) */ +/* remove a vterm from hvc tty operation (module_exit or hotplug remove) */ extern int __devexit hvc_remove(struct hvc_struct *hp); +/* data available */ +int hvc_poll(struct hvc_struct *hp); +void hvc_kick(void); + +/* default notifier for irq based notification */ +extern int notifier_add_irq(struct hvc_struct *hp, int data); +extern void notifier_del_irq(struct hvc_struct *hp, int data); + #if defined(CONFIG_XMON) && defined(CONFIG_SMP) #include -- cgit v1.2.3