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authorLinus Torvalds <torvalds@linux-foundation.org>2008-10-20 13:22:50 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-10-20 13:23:01 -0700
commit9301975ec251bab1ad7cfcb84a688b26187e4e4a (patch)
tree91e48be0bdc67cbcb75bc8a299a3dcf168e0a814 /drivers/serial/8250.c
parent7110879cf2afbfb7af79675f5ff109e63d631c25 (diff)
parentdd3a1db900f2a215a7d7dd71b836e149a6cf5fed (diff)
Merge branch 'genirq-v28-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
This merges branches irq/genirq, irq/sparseirq-v4, timers/hpet-percpu and x86/uv. The sparseirq branch is just preliminary groundwork: no sparse IRQs are actually implemented by this tree anymore - just the new APIs are added while keeping the old way intact as well (the new APIs map 1:1 to irq_desc[]). The 'real' sparse IRQ support will then be a relatively small patch ontop of this - with a v2.6.29 merge target. * 'genirq-v28-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (178 commits) genirq: improve include files intr_remapping: fix typo io_apic: make irq_mis_count available on 64-bit too genirq: fix name space collisions of nr_irqs in arch/* genirq: fix name space collision of nr_irqs in autoprobe.c genirq: use iterators for irq_desc loops proc: fixup irq iterator genirq: add reverse iterator for irq_desc x86: move ack_bad_irq() to irq.c x86: unify show_interrupts() and proc helpers x86: cleanup show_interrupts genirq: cleanup the sparseirq modifications genirq: remove artifacts from sparseirq removal genirq: revert dynarray genirq: remove irq_to_desc_alloc genirq: remove sparse irq code genirq: use inline function for irq_to_desc genirq: consolidate nr_irqs and for_each_irq_desc() x86: remove sparse irq from Kconfig genirq: define nr_irqs for architectures with GENERIC_HARDIRQS=n ...
Diffstat (limited to 'drivers/serial/8250.c')
-rw-r--r--drivers/serial/8250.c69
1 files changed, 56 insertions, 13 deletions
diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
index 1528de23a65..303272af386 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 */
@@ -2447,7 +2493,7 @@ static void serial8250_config_port(struct uart_port *port, int flags)
static int
serial8250_verify_port(struct uart_port *port, struct serial_struct *ser)
{
- if (ser->irq >= NR_IRQS || ser->irq < 0 ||
+ if (ser->irq >= nr_irqs || ser->irq < 0 ||
ser->baud_base < 9600 || ser->type < PORT_UNKNOWN ||
ser->type >= ARRAY_SIZE(uart_config) || ser->type == PORT_CIRRUS ||
ser->type == PORT_STARTECH)
@@ -2967,7 +3013,7 @@ 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;
@@ -2976,9 +3022,6 @@ 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
@@ -3006,15 +3049,15 @@ 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;
}