Hi Liviu, On Mon, Jan 12, 2015 at 3:45 PM, Liviu Dudau <Liviu.Dudau@xxxxxxx> wrote: > On Mon, Jan 05, 2015 at 10:37:47AM +0000, Geert Uytterhoeven wrote: >> A while ago, I wondered: >> >> | It's my understanding GIC_CPU_MASK_SIMPLE should reflect the actual number >> | of CPU cores the interrupt is wired too. Is that correct? >> | >> | [Fixes for incorrect masks on shmobile] >> | >> | Should it be "GIC_CPU_MASK_SIMPLE(8)" on big.LITTLE configurations >> | with four Cortex-A15 cores and four Cortex-A7 cores? >> | Or should the interrupts be delivered to the four Cortex-A15 cores >> | only by default? >> | >> | Note that incorrect masks for GIC PPI interrupts are not limited to >> | shmobile. Presumably the interrupt specifiers got copied around a lot, >> | cfr. the proliferation of "GIC_CPU_MASK_SIMPLE(4)" (and the older >> | hardcoded "0xf0x" variant) in various dtsi files, not always limited to >> | quad-core CPUs. >> >> In the mean time, arch/arm64/boot/dts/arm/juno.dts got added, which has 2 A57 >> cores and 4 A53 cores, and uses GIC_CPU_MASK_SIMPLE(6), so it seems like >> my two RFC patches to use GIC_CPU_MASK_SIMPLE(8) for 4 A15 cores and 4 >> A7 cores are actually correct? >> >> Thanks for your comments! >> >> References: >> 1. Original RFC series: >> [PATCH/RFC 0/4] ARM: shmobile: Correct masks for GIC PPI interrupts >> http://lists.infradead.org/pipermail/linux-arm-kernel/2014-November/306743.html >> 2. RFC patches: >> a. [PATCH/RFC 3/4] ARM: shmobile: r8a7790: Correct mask for GIC >> PPI interrupts >> http://lists.infradead.org/pipermail/linux-arm-kernel/2014-November/306741.html >> b. [PATCH/RFC 4/4] ARM: shmobile: r8a73a4: Correct mask for GIC >> PPI interrupts >> http://lists.infradead.org/pipermail/linux-arm-kernel/2014-November/306740.html > Your patches are correct, the mask should reflect the number of CPUs present *and* they way > they are wired in the GIC. AFAIK, HW designers have been sane so far and wired the CPUs > in sequence in the GIC, but I lack inside knowledge of the shmobile design. Thanks, I will resend them. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
