From 12b20ded6f980d9161b1c6b062560b65a7295e1c Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Wed, 28 Nov 2007 10:46:22 -0800 Subject: [PATCH] kobject: convert hvc_console to use kref, not kobject hvc_console is using a kobject only for reference counting, nothing else. So switch it to use a kref instead, which is all that is needed, and is much smaller. Cc: Anton Blanchard Cc: Paul Mackerras Cc: Benjamin Herrenschmidt Cc: Ryan S. Arnold Cc: Kay Sievers Signed-off-by: Greg Kroah-Hartman --- drivers/char/hvc_console.c | 80 ++++++++++++++++---------------------- 1 file changed, 33 insertions(+), 47 deletions(-) diff --git a/drivers/char/hvc_console.c b/drivers/char/hvc_console.c index 8252f866853..480fae29c9b 100644 --- a/drivers/char/hvc_console.c +++ b/drivers/char/hvc_console.c @@ -27,7 +27,7 @@ #include #include #include -#include +#include #include #include #include @@ -89,7 +89,7 @@ struct hvc_struct { int irq_requested; int irq; struct list_head next; - struct kobject kobj; /* ref count & hvc_struct lifetime */ + struct kref kref; /* ref count & hvc_struct lifetime */ }; /* dynamic list of hvc_struct instances */ @@ -110,7 +110,7 @@ static int last_hvc = -1; /* * Do not call this function with either the hvc_structs_lock or the hvc_struct - * lock held. If successful, this function increments the kobject reference + * lock held. If successful, this function increments the kref reference * count against the target hvc_struct so it should be released when finished. */ static struct hvc_struct *hvc_get_by_index(int index) @@ -123,7 +123,7 @@ static struct hvc_struct *hvc_get_by_index(int index) list_for_each_entry(hp, &hvc_structs, next) { spin_lock_irqsave(&hp->lock, flags); if (hp->index == index) { - kobject_get(&hp->kobj); + kref_get(&hp->kref); spin_unlock_irqrestore(&hp->lock, flags); spin_unlock(&hvc_structs_lock); return hp; @@ -242,6 +242,23 @@ static int __init hvc_console_init(void) } console_initcall(hvc_console_init); +/* callback when the kboject ref count reaches zero. */ +static void destroy_hvc_struct(struct kref *kref) +{ + struct hvc_struct *hp = container_of(kref, struct hvc_struct, kref); + unsigned long flags; + + spin_lock(&hvc_structs_lock); + + spin_lock_irqsave(&hp->lock, flags); + list_del(&(hp->next)); + spin_unlock_irqrestore(&hp->lock, flags); + + spin_unlock(&hvc_structs_lock); + + kfree(hp); +} + /* * hvc_instantiate() is an early console discovery method which locates * consoles * prior to the vio subsystem discovering them. Hotplugged @@ -261,7 +278,7 @@ int hvc_instantiate(uint32_t vtermno, int index, struct hv_ops *ops) /* make sure no no tty has been registered in this index */ hp = hvc_get_by_index(index); if (hp) { - kobject_put(&hp->kobj); + kref_put(&hp->kref, destroy_hvc_struct); return -1; } @@ -318,9 +335,8 @@ static int hvc_open(struct tty_struct *tty, struct file * filp) unsigned long flags; int irq = 0; int rc = 0; - struct kobject *kobjp; - /* Auto increments kobject reference if found. */ + /* Auto increments kref reference if found. */ if (!(hp = hvc_get_by_index(tty->index))) return -ENODEV; @@ -341,8 +357,6 @@ static int hvc_open(struct tty_struct *tty, struct file * filp) if (irq) hp->irq_requested = 1; - kobjp = &hp->kobj; - spin_unlock_irqrestore(&hp->lock, flags); /* check error, fallback to non-irq */ if (irq) @@ -352,7 +366,7 @@ static int hvc_open(struct tty_struct *tty, struct file * filp) * If the request_irq() fails and we return an error. The tty layer * will call hvc_close() after a failed open but we don't want to clean * up there so we'll clean up here and clear out the previously set - * tty fields and return the kobject reference. + * tty fields and return the kref reference. */ if (rc) { spin_lock_irqsave(&hp->lock, flags); @@ -360,7 +374,7 @@ static int hvc_open(struct tty_struct *tty, struct file * filp) hp->irq_requested = 0; spin_unlock_irqrestore(&hp->lock, flags); tty->driver_data = NULL; - kobject_put(kobjp); + kref_put(&hp->kref, destroy_hvc_struct); printk(KERN_ERR "hvc_open: request_irq failed with rc %d.\n", rc); } /* Force wakeup of the polling thread */ @@ -372,7 +386,6 @@ static int hvc_open(struct tty_struct *tty, struct file * filp) static void hvc_close(struct tty_struct *tty, struct file * filp) { struct hvc_struct *hp; - struct kobject *kobjp; int irq = 0; unsigned long flags; @@ -382,7 +395,7 @@ static void hvc_close(struct tty_struct *tty, struct file * filp) /* * No driver_data means that this close was issued after a failed * hvc_open by the tty layer's release_dev() function and we can just - * exit cleanly because the kobject reference wasn't made. + * exit cleanly because the kref reference wasn't made. */ if (!tty->driver_data) return; @@ -390,7 +403,6 @@ static void hvc_close(struct tty_struct *tty, struct file * filp) hp = tty->driver_data; spin_lock_irqsave(&hp->lock, flags); - kobjp = &hp->kobj; if (--hp->count == 0) { if (hp->irq_requested) irq = hp->irq; @@ -417,7 +429,7 @@ static void hvc_close(struct tty_struct *tty, struct file * filp) spin_unlock_irqrestore(&hp->lock, flags); } - kobject_put(kobjp); + kref_put(&hp->kref, destroy_hvc_struct); } static void hvc_hangup(struct tty_struct *tty) @@ -426,7 +438,6 @@ static void hvc_hangup(struct tty_struct *tty) unsigned long flags; int irq = 0; int temp_open_count; - struct kobject *kobjp; if (!hp) return; @@ -443,7 +454,6 @@ static void hvc_hangup(struct tty_struct *tty) return; } - kobjp = &hp->kobj; temp_open_count = hp->count; hp->count = 0; hp->n_outbuf = 0; @@ -457,7 +467,7 @@ static void hvc_hangup(struct tty_struct *tty) free_irq(irq, hp); while(temp_open_count) { --temp_open_count; - kobject_put(kobjp); + kref_put(&hp->kref, destroy_hvc_struct); } } @@ -729,27 +739,6 @@ static const struct tty_operations hvc_ops = { .chars_in_buffer = hvc_chars_in_buffer, }; -/* callback when the kboject ref count reaches zero. */ -static void destroy_hvc_struct(struct kobject *kobj) -{ - struct hvc_struct *hp = container_of(kobj, struct hvc_struct, kobj); - unsigned long flags; - - spin_lock(&hvc_structs_lock); - - spin_lock_irqsave(&hp->lock, flags); - list_del(&(hp->next)); - spin_unlock_irqrestore(&hp->lock, flags); - - spin_unlock(&hvc_structs_lock); - - kfree(hp); -} - -static struct kobj_type hvc_kobj_type = { - .release = destroy_hvc_struct, -}; - struct hvc_struct __devinit *hvc_alloc(uint32_t vtermno, int irq, struct hv_ops *ops, int outbuf_size) { @@ -776,8 +765,7 @@ struct hvc_struct __devinit *hvc_alloc(uint32_t vtermno, int irq, hp->outbuf_size = outbuf_size; hp->outbuf = &((char *)hp)[ALIGN(sizeof(*hp), sizeof(long))]; - kobject_init(&hp->kobj); - hp->kobj.ktype = &hvc_kobj_type; + kref_init(&hp->kref); spin_lock_init(&hp->lock); spin_lock(&hvc_structs_lock); @@ -806,12 +794,10 @@ struct hvc_struct __devinit *hvc_alloc(uint32_t vtermno, int irq, int __devexit hvc_remove(struct hvc_struct *hp) { unsigned long flags; - struct kobject *kobjp; struct tty_struct *tty; spin_lock_irqsave(&hp->lock, flags); tty = hp->tty; - kobjp = &hp->kobj; if (hp->index < MAX_NR_HVC_CONSOLES) vtermnos[hp->index] = -1; @@ -821,12 +807,12 @@ int __devexit hvc_remove(struct hvc_struct *hp) spin_unlock_irqrestore(&hp->lock, flags); /* - * We 'put' the instance that was grabbed when the kobject instance - * was initialized using kobject_init(). Let the last holder of this - * kobject cause it to be removed, which will probably be the tty_hangup + * We 'put' the instance that was grabbed when the kref instance + * was initialized using kref_init(). Let the last holder of this + * kref cause it to be removed, which will probably be the tty_hangup * below. */ - kobject_put(kobjp); + kref_put(&hp->kref, destroy_hvc_struct); /* * This function call will auto chain call hvc_hangup. The tty should -- 2.41.1