Hi, On Sat, Aug 26, 2023 at 3:37 AM Marc Zyngier <m...@kernel.org> wrote: > > On Thu, 24 Aug 2023 16:30:27 +0100, > Douglas Anderson <diand...@chromium.org> wrote: > > > > As of commit 6abbd6988971 ("irqchip/gic, gic-v3: Make SGIs use > > handle_percpu_devid_irq()") SGIs are treated the same as PPIs/EPPIs > > and use handle_percpu_devid_irq() by default. Unfortunately, > > handle_percpu_devid_irq() isn't NMI safe, and so to run in an NMI > > context those should use handle_percpu_devid_fasteoi_nmi(). > > > > In order to accomplish this, we just have to make room for SGIs in the > > array of refcounts that keeps track of which interrupts are set as > > NMI. We also rename the array and create a new indexing scheme that > > accounts for SGIs. > > > > Also, enable NMI support prior to gic_smp_init() as allocation of SGIs > > as IRQs/NMIs happen as part of this routine. > > > > Co-developed-by: Sumit Garg <sumit.g...@linaro.org> > > Signed-off-by: Sumit Garg <sumit.g...@linaro.org> > > Signed-off-by: Douglas Anderson <diand...@chromium.org> > > --- > > In v10 I removed the previous Reviewed-by and Tested-by tags since the > > patch contents changed pretty drastically. > > > > I'll also note that this change is a little more black magic to me > > than others in this series. I don't have a massive amounts of > > familiarity with all the moving parts of gic-v3, so I mostly just > > followed Mark Rutland's advice [1]. Please pay extra attention to make > > sure I didn't do anything too terrible. > > > > Mark's advice wasn't a full patch and I ended up doing a bit of work > > to translate it to reality, so I did not add him as "Co-developed-by" > > here. Mark: if you would like this tag then please provide it and your > > Signed-off-by. I certainly won't object. > > > > [1] > > https://lore.kernel.org/r/znc-yrqopo0pa...@fvff77s0q05n.cambridge.arm.com > > > > (no changes since v10) > > > > Changes in v10: > > - Rewrite as needed for 5.11+ as per Mark Rutland and Sumit. > > > > drivers/irqchip/irq-gic-v3.c | 54 ++++++++++++++++++++++++------------ > > 1 file changed, 36 insertions(+), 18 deletions(-) > > > > diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c > > index eedfa8e9f077..49d18cf3f636 100644 > > --- a/drivers/irqchip/irq-gic-v3.c > > +++ b/drivers/irqchip/irq-gic-v3.c > > @@ -78,6 +78,8 @@ static DEFINE_STATIC_KEY_TRUE(supports_deactivate_key); > > #define GIC_LINE_NR min(GICD_TYPER_SPIS(gic_data.rdists.gicd_typer), > > 1020U) > > #define GIC_ESPI_NR GICD_TYPER_ESPIS(gic_data.rdists.gicd_typer) > > > > +#define SGI_NR 16 > > Why 16? We only allocate 8, as the other 8 are potentially stolen by > the secure side. We do try and initialise them all so that they have a > known state if they were actually configured as Group-1NS, but we > don't use them. > > I understand that this simplifies the indexing in the rdist_nmi_refs > array and I'm not going to cry over 32 wasted bytes, but this > definitely deserves a comment.
Good point. I'll plan to wait another day or two to see if any other feedback shows up and then send a v12 with this plus Stephen's nit fixes on one of the other patches. -Doug _______________________________________________ Kgdb-bugreport mailing list Kgdb-bugreport@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kgdb-bugreport