Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756239AbYJEQGZ (ORCPT ); Sun, 5 Oct 2008 12:06:25 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754820AbYJEQFR (ORCPT ); Sun, 5 Oct 2008 12:05:17 -0400 Received: from earthlight.etchedpixels.co.uk ([81.2.110.250]:54842 "EHLO lxorguk.ukuu.org.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754700AbYJEQFN (ORCPT ); Sun, 5 Oct 2008 12:05:13 -0400 From: Alan Cox Subject: [PATCH 05/76] 8250: Remove NR_IRQ usage To: linux-kernel@vger.kernel.org Date: Sun, 05 Oct 2008 17:05:13 +0100 Message-ID: <20081005160509.1997.88329.stgit@localhost.localdomain> In-Reply-To: <20081005160231.1997.10462.stgit@localhost.localdomain> References: <20081005160231.1997.10462.stgit@localhost.localdomain> User-Agent: StGIT/0.14.2 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5509 Lines: 215 There are plans afoot to make the IRQ ranges dynamic. In that situation we don't want drivers having their own huge arrays for per IRQ data so use a hash Signed-off-by: Alan Cox --- drivers/serial/68328serial.c | 11 +----- drivers/serial/8250.c | 74 +++++++++++++++++++++++++++++++++--------- 2 files changed, 60 insertions(+), 25 deletions(-) diff --git a/drivers/serial/68328serial.c b/drivers/serial/68328serial.c index 381b12a..277b78d 100644 --- a/drivers/serial/68328serial.c +++ b/drivers/serial/68328serial.c @@ -66,7 +66,6 @@ #endif static struct m68k_serial m68k_soft[NR_PORTS]; -struct m68k_serial *IRQ_ports[NR_IRQS]; static unsigned int uart_irqs[NR_PORTS] = UART_IRQ_DEFNS; @@ -375,15 +374,11 @@ clear_and_return: */ irqreturn_t rs_interrupt(int irq, void *dev_id) { - struct m68k_serial * info; + struct m68k_serial * info = dev_id; m68328_uart *uart; unsigned short rx; unsigned short tx; - info = IRQ_ports[irq]; - if(!info) - return IRQ_NONE; - uart = &uart_addr[info->line]; rx = uart->urx.w; @@ -1383,8 +1378,6 @@ rs68328_init(void) info->port, info->irq); printk(" is a builtin MC68328 UART\n"); - IRQ_ports[info->irq] = info; /* waste of space */ - #ifdef CONFIG_M68VZ328 if (i > 0 ) PJSEL &= 0xCF; /* PSW enable second port output */ @@ -1393,7 +1386,7 @@ rs68328_init(void) if (request_irq(uart_irqs[i], rs_interrupt, IRQF_DISABLED, - "M68328_UART", NULL)) + "M68328_UART", info)) panic("Unable to attach 68328 serial interrupt\n"); } local_irq_restore(flags); diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c index 9ccc563..9f5e60d 100644 --- a/drivers/serial/8250.c +++ b/drivers/serial/8250.c @@ -39,7 +39,7 @@ #include #include -#include +#include #include #include "8250.h" @@ -145,11 +145,15 @@ 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. @@ -266,7 +270,7 @@ static const struct serial8250_config uart_config[] = { }, }; -#if defined (CONFIG_SERIAL_8250_AU1X00) +#if defined(CONFIG_SERIAL_8250_AU1X00) /* Au1x00 UART hardware has a weird register layout */ static const u8 au_io_in_map[] = { @@ -1535,15 +1539,43 @@ 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) { @@ -1567,14 +1599,27 @@ 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; - BUG_ON(i->head == NULL); + 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 */ @@ -2950,7 +2995,7 @@ 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; @@ -2959,9 +3004,6 @@ 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); - ret = uart_register_driver(&serial8250_reg); if (ret) goto out; @@ -2984,11 +3026,11 @@ 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: uart_unregister_driver(&serial8250_reg); - out: +out: return ret; } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/