diff options
Diffstat (limited to 'arch/mips/dec/ioasic-irq.c')
| -rw-r--r-- | arch/mips/dec/ioasic-irq.c | 43 |
1 files changed, 37 insertions, 6 deletions
diff --git a/arch/mips/dec/ioasic-irq.c b/arch/mips/dec/ioasic-irq.c index 4b3e3a4375a..e04d973ce5a 100644 --- a/arch/mips/dec/ioasic-irq.c +++ b/arch/mips/dec/ioasic-irq.c @@ -1,7 +1,7 @@ /* * DEC I/O ASIC interrupts. * - * Copyright (c) 2002, 2003 Maciej W. Rozycki + * Copyright (c) 2002, 2003, 2013 Maciej W. Rozycki * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License @@ -51,22 +51,51 @@ static struct irq_chip ioasic_irq_type = { .irq_unmask = unmask_ioasic_irq, }; -void clear_ioasic_dma_irq(unsigned int irq) +static void clear_ioasic_dma_irq(struct irq_data *d) { u32 sir; - sir = ~(1 << (irq - ioasic_irq_base)); + sir = ~(1 << (d->irq - ioasic_irq_base)); ioasic_write(IO_REG_SIR, sir); + fast_iob(); } static struct irq_chip ioasic_dma_irq_type = { .name = "IO-ASIC-DMA", - .irq_ack = ack_ioasic_irq, + .irq_ack = clear_ioasic_dma_irq, .irq_mask = mask_ioasic_irq, - .irq_mask_ack = ack_ioasic_irq, .irq_unmask = unmask_ioasic_irq, + .irq_eoi = clear_ioasic_dma_irq, }; +/* + * I/O ASIC implements two kinds of DMA interrupts, informational and + * error interrupts. + * + * The formers do not stop DMA and should be cleared as soon as possible + * so that if they retrigger before the handler has completed, usually as + * a side effect of actions taken by the handler, then they are reissued. + * These use the `handle_edge_irq' handler that clears the request right + * away. + * + * The latters stop DMA and do not resume it until the interrupt has been + * cleared. This cannot be done until after a corrective action has been + * taken and this also means they will not retrigger. Therefore they use + * the `handle_fasteoi_irq' handler that only clears the request on the + * way out. Because MIPS processor interrupt inputs, one of which the I/O + * ASIC is cascaded to, are level-triggered it is recommended that error + * DMA interrupt action handlers are registered with the IRQF_ONESHOT flag + * set so that they are run with the interrupt line masked. + * + * This mask has `1' bits in the positions of informational interrupts. + */ +#define IO_IRQ_DMA_INFO \ + (IO_IRQ_MASK(IO_INR_SCC0A_RXDMA) | \ + IO_IRQ_MASK(IO_INR_SCC1A_RXDMA) | \ + IO_IRQ_MASK(IO_INR_ISDN_TXDMA) | \ + IO_IRQ_MASK(IO_INR_ISDN_RXDMA) | \ + IO_IRQ_MASK(IO_INR_ASC_DMA)) + void __init init_ioasic_irqs(int base) { int i; @@ -79,7 +108,9 @@ void __init init_ioasic_irqs(int base) irq_set_chip_and_handler(i, &ioasic_irq_type, handle_level_irq); for (; i < base + IO_IRQ_LINES; i++) - irq_set_chip(i, &ioasic_dma_irq_type); + irq_set_chip_and_handler(i, &ioasic_dma_irq_type, + 1 << (i - base) & IO_IRQ_DMA_INFO ? + handle_edge_irq : handle_fasteoi_irq); ioasic_irq_base = base; } |