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authorAlan Cox <alan@redhat.com>2008-08-19 20:49:40 -0700
committerIngo Molnar <mingo@elte.hu>2008-10-16 16:52:02 +0200
commit25db8ad5c56700e7716fe23426b16c5e3b1674b4 (patch)
treea4f4864f7fb83b091289f4ef73279d8d8b9f34c6 /drivers/serial/8250.c
parent5fef06e8c8c52aa7170dbbb068aa996d83738d38 (diff)
serial, 8250: remove NR_IRQ usage
Works on my test box with a quick test. Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'drivers/serial/8250.c')
-rw-r--r--drivers/serial/8250.c67
1 files changed, 55 insertions, 12 deletions
diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
index d3ca7d32abe..c66bb44c474 100644
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -156,11 +156,15 @@ struct uart_8250_port {
};
struct irq_info {
- spinlock_t lock;
+ struct hlist_node node;
+ int irq;
+ spinlock_t lock; /* Protects list not the hash */
struct list_head *head;
};
-static struct irq_info irq_lists[NR_IRQS];
+#define NR_IRQ_HASH 32 /* Can be adjusted later */
+static struct hlist_head irq_lists[NR_IRQ_HASH];
+static DEFINE_MUTEX(hash_mutex); /* Used to walk the hash */
/*
* Here we define the default xmit fifo size used for each type of UART.
@@ -1545,15 +1549,43 @@ static void serial_do_unlink(struct irq_info *i, struct uart_8250_port *up)
BUG_ON(i->head != &up->list);
i->head = NULL;
}
-
spin_unlock_irq(&i->lock);
+ /* List empty so throw away the hash node */
+ if (i->head == NULL) {
+ hlist_del(&i->node);
+ kfree(i);
+ }
}
static int serial_link_irq_chain(struct uart_8250_port *up)
{
- struct irq_info *i = irq_lists + up->port.irq;
+ struct hlist_head *h;
+ struct hlist_node *n;
+ struct irq_info *i;
int ret, irq_flags = up->port.flags & UPF_SHARE_IRQ ? IRQF_SHARED : 0;
+ mutex_lock(&hash_mutex);
+
+ h = &irq_lists[up->port.irq % NR_IRQ_HASH];
+
+ hlist_for_each(n, h) {
+ i = hlist_entry(n, struct irq_info, node);
+ if (i->irq == up->port.irq)
+ break;
+ }
+
+ if (n == NULL) {
+ i = kzalloc(sizeof(struct irq_info), GFP_KERNEL);
+ if (i == NULL) {
+ mutex_unlock(&hash_mutex);
+ return -ENOMEM;
+ }
+ spin_lock_init(&i->lock);
+ i->irq = up->port.irq;
+ hlist_add_head(&i->node, h);
+ }
+ mutex_unlock(&hash_mutex);
+
spin_lock_irq(&i->lock);
if (i->head) {
@@ -1577,14 +1609,28 @@ static int serial_link_irq_chain(struct uart_8250_port *up)
static void serial_unlink_irq_chain(struct uart_8250_port *up)
{
- struct irq_info *i = irq_lists + up->port.irq;
+ struct irq_info *i;
+ struct hlist_node *n;
+ struct hlist_head *h;
+ mutex_lock(&hash_mutex);
+
+ h = &irq_lists[up->port.irq % NR_IRQ_HASH];
+
+ hlist_for_each(n, h) {
+ i = hlist_entry(n, struct irq_info, node);
+ if (i->irq == up->port.irq)
+ break;
+ }
+
+ BUG_ON(n == NULL);
BUG_ON(i->head == NULL);
if (list_empty(i->head))
free_irq(up->port.irq, i);
serial_do_unlink(i, up);
+ mutex_unlock(&hash_mutex);
}
/* Base timer interval for polling */
@@ -2960,7 +3006,7 @@ EXPORT_SYMBOL(serial8250_unregister_port);
static int __init serial8250_init(void)
{
- int ret, i;
+ int ret;
if (nr_uarts > UART_NR)
nr_uarts = UART_NR;
@@ -2969,9 +3015,6 @@ static int __init serial8250_init(void)
"%d ports, IRQ sharing %sabled\n", nr_uarts,
share_irqs ? "en" : "dis");
- for (i = 0; i < NR_IRQS; i++)
- spin_lock_init(&irq_lists[i].lock);
-
#ifdef CONFIG_SPARC
ret = sunserial_register_minors(&serial8250_reg, UART_NR);
#else
@@ -2999,15 +3042,15 @@ static int __init serial8250_init(void)
goto out;
platform_device_del(serial8250_isa_devs);
- put_dev:
+put_dev:
platform_device_put(serial8250_isa_devs);
- unreg_uart_drv:
+unreg_uart_drv:
#ifdef CONFIG_SPARC
sunserial_unregister_minors(&serial8250_reg, UART_NR);
#else
uart_unregister_driver(&serial8250_reg);
#endif
- out:
+out:
return ret;
}