Messages in this thread Patch in this message | | | From | Yinghai Lu <> | Subject | [PATCH 21/25] serial: change remove NR_IRQS in 8250.c v2 | Date | Sat, 2 Aug 2008 19:59:21 -0700 |
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use small array with index to handle irq locking for serial port hope 32 slot is enough
v2: according to Eric, move irq_no into irq_info, and not clean irq_no
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> --- drivers/serial/8250.c | 45 +++++++++++++++++++++++++++++++++++++++++---- 1 files changed, 41 insertions(+), 4 deletions(-)
diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c index 3920324..595b956 100644 --- a/drivers/serial/8250.c +++ b/drivers/serial/8250.c @@ -147,9 +147,39 @@ struct uart_8250_port { struct irq_info { spinlock_t lock; struct list_head *head; + int irq_no; }; -static struct irq_info irq_lists[NR_IRQS]; +#define NR_IRQ_INFO 32 + +static struct irq_info irq_lists[NR_IRQ_INFO] = { + [0 ... NR_IRQ_INFO-1] = { + .irq_no = -1, + } +}; + +static struct irq_info *get_irq_info(int irq, int with_free) +{ + int i, first_free = -1; + + for (i = 0; i < NR_IRQ_INFO; i++) { + if (irq_lists[i].irq_no == irq) + return &irq_lists[i]; + if (irq_lists[i].irq_no == -1 && first_free == -1) + first_free = i; + } + if (!with_free) + return NULL; + + if (first_free != -1) { + irq_lists[first_free].irq_no = irq; + return &irq_lists[first_free]; + } + + WARN_ON("NR_IRQ_INFO too small"); + + return NULL; +} /* * Here we define the default xmit fifo size used for each type of UART. @@ -1554,9 +1584,12 @@ static void serial_do_unlink(struct irq_info *i, struct uart_8250_port *up) static int serial_link_irq_chain(struct uart_8250_port *up) { - struct irq_info *i = irq_lists + up->port.irq; + struct irq_info *i = get_irq_info(up->port.irq, 1); int ret, irq_flags = up->port.flags & UPF_SHARE_IRQ ? IRQF_SHARED : 0; + if (!i) + return -1; + spin_lock_irq(&i->lock); if (i->head) { @@ -1580,7 +1613,11 @@ 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; + int irq_no = up->port.irq; + struct irq_info *i = get_irq_info(irq_no, 0); + + if (!i) + return; BUG_ON(i->head == NULL); @@ -2964,7 +3001,7 @@ 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++) + for (i = 0; i < NR_IRQ_INFO; i++) spin_lock_init(&irq_lists[i].lock); ret = uart_register_driver(&serial8250_reg); -- 1.5.4.5
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