On Fri, 9 Jan 2015, Marc Zyngier wrote: > Hi Jiang, > > On 09/01/15 03:07, Jiang Liu wrote: > > On 2015/1/9 1:32, Marc Zyngier wrote: > >> With the landing of stacked irq domains in 3.19, we have ended up in a > >> situation where we have a stack of IRQ controllers, each with their > >> set of flags, but the core code is only able to look at the top-most, > >> which is not very helpful. This small series is trying to fix this. > >> > >> The first patch converts all access to desc->irq_data.chip->flags to > >> using an accessor, without changing anything else. The second patch > >> adds some logic to combine these flags as we allocate the interrupts, > >> ultimately storing the resulting set as part of the irq_desc > >> structure. > >> > >> We end-up with a configuration where the flags can either be located > >> in the irq_chip structure (non stacked case), or in the irq_desc > >> (stacked case). While this isn't really ideal, this gives at least the > >> right level of information to the rest of the IRQ framework. > > Hi Mark, > > By this way, we need to aggregate irq_chip flags for every > > irq. How about changing irq_desc_get_chip_flags(struct irq_desc *desc) > > to irq_desc_check_chip_flags(struct irq_desc *desc, unsigned int flags) > > which dynamically walks the stacked irqchips? > > That was the other option, but I felt that going through the list of > irqchips was not a very nice idea performance wise. This is used is some > moderately hot paths (cond_unmask_eoi_irq, for example), and I wondered > if we wanted to pay this price at runtime...
We rather do it at setup time. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/