serial, 8250: remove NR_IRQ usage

[linux-2.6-omap-h63xx.git] / drivers / serial / 8250.c

diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
index db2cdc103c884ef70889039740d602e785e0fbe4..c66bb44c47477e4bf7dfe6b3be5a1d746ae45b28 100644 (file)
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -57,6 +57,13 @@ static unsigned int share_irqs = SERIAL8250_SHARE_IRQS;
 
 static unsigned int nr_uarts = CONFIG_SERIAL_8250_RUNTIME_UARTS;
 
+static struct uart_driver serial8250_reg;
+
+static int serial_index(struct uart_port *port)
+{
+       return (serial8250_reg.minor - 64) + port->line;
+}
+
 /*
  * Debugging.
  */
@@ -149,11 +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.
@@ -997,7 +1008,7 @@ static void autoconfig(struct uart_8250_port *up, unsigned int probeflags)
                return;
 
        DEBUG_AUTOCONF("ttyS%d: autoconf (0x%04x, 0x%p): ",
-                       up->port.line, up->port.iobase, up->port.membase);
+                      serial_index(&up->port), up->port.iobase, up->port.membase);
 
        /*
         * We really do need global IRQs disabled here - we're going to
@@ -1132,8 +1143,8 @@ static void autoconfig(struct uart_8250_port *up, unsigned int probeflags)
        if (up->capabilities != uart_config[up->port.type].flags) {
                printk(KERN_WARNING
                       "ttyS%d: detected caps %08x should be %08x\n",
-                       up->port.line, up->capabilities,
-                       uart_config[up->port.type].flags);
+                      serial_index(&up->port), up->capabilities,
+                      uart_config[up->port.type].flags);
        }
 
        up->port.fifosize = uart_config[up->port.type].fifo_size;
@@ -1538,15 +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) {
@@ -1570,14 +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 */
@@ -1857,7 +1910,8 @@ static int serial8250_startup(struct uart_port *port)
         */
        if (!(up->port.flags & UPF_BUGGY_UART) &&
            (serial_inp(up, UART_LSR) == 0xff)) {
-               printk("ttyS%d: LSR safety check engaged!\n", up->port.line);
+               printk(KERN_INFO "ttyS%d: LSR safety check engaged!\n",
+                      serial_index(&up->port));
                return -ENODEV;
        }
 
@@ -1912,7 +1966,8 @@ static int serial8250_startup(struct uart_port *port)
                 */
                if (!(iir1 & UART_IIR_NO_INT) && (iir & UART_IIR_NO_INT)) {
                        up->bugs |= UART_BUG_THRE;
-                       pr_debug("ttyS%d - using backup timer\n", port->line);
+                       pr_debug("ttyS%d - using backup timer\n",
+                                serial_index(port));
                }
        }
 
@@ -1972,7 +2027,7 @@ static int serial8250_startup(struct uart_port *port)
                if (!(up->bugs & UART_BUG_TXEN)) {
                        up->bugs |= UART_BUG_TXEN;
                        pr_debug("ttyS%d - enabling bad tx status workarounds\n",
-                                port->line);
+                                serial_index(port));
                }
        } else {
                up->bugs &= ~UART_BUG_TXEN;
@@ -2633,7 +2688,6 @@ static int serial8250_console_early_setup(void)
        return serial8250_find_port_for_earlycon();
 }
 
-static struct uart_driver serial8250_reg;
 static struct console serial8250_console = {
        .name           = "ttyS",
        .write          = serial8250_console_write,
@@ -2952,7 +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;
@@ -2988,15 +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;
 }