Date: Tue, 17 May 2016 13:19:45 +0100 From: Andrew Turner <andrew@fubar.geek.nz> To: Zbigniew Bodek <zbb@semihalf.com> Cc: Andrew Turner <andrew@freebsd.org>, src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: Re: svn commit: r299944 - in head/sys: arm64/arm64 conf Message-ID: <20160517131945.65cd9ccc@zapp> In-Reply-To: <CAG7dG%2BwRO%2BD2SH2jX546eXAOsisCU8To5hP6uE08Nd8=hdmWeA@mail.gmail.com> References: <201605161407.u4GE7h9n002600@repo.freebsd.org> <CAG7dG%2BwRO%2BD2SH2jX546eXAOsisCU8To5hP6uE08Nd8=hdmWeA@mail.gmail.com>
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On Mon, 16 May 2016 18:08:49 +0200 Zbigniew Bodek <zbb@semihalf.com> wrote: > Hello Andrew, > > I think committing this code should be preceded by at least brief > review. Few remarks to the code found on the first glance below. See below for comments. > > Kind regards > zbb > > 2016-05-16 16:07 GMT+02:00 Andrew Turner <andrew@freebsd.org>: > > > Author: andrew > > Date: Mon May 16 14:07:43 2016 > > New Revision: 299944 > > URL: https://svnweb.freebsd.org/changeset/base/299944 > > > > Log: > > Add intrng support to the GICv3 driver. It lacks ITS support so > > won't handle > > MSI or MSI-X interrupts, however this is enought to boot FreeBSD > > under the > > ARM Foundation Model with a GICv3 interrupt controller. > > > > Approved by: ABT Systems Ltd > > Relnotes: yes > > Sponsored by: The FreeBSD Foundation ... > > +#ifdef INTRNG > > +int > > +arm_gic_v3_intr(void *arg) > > +{ > > + struct gic_v3_softc *sc = arg; > > + struct gic_v3_irqsrc *gi; > > + uint64_t active_irq; > > + struct trapframe *tf; > > + bool first; > > + > > + first = true; > > + > > + while (1) { > > + if (CPU_MATCH_ERRATA_CAVIUM_THUNDER_1_1) { > > + /* > > + * Hardware: Cavium ThunderX > > + * Chip revision: Pass 1.0 (early > > version) > > + * Pass 1.1 > > (production) > > + * ERRATUM: 22978, 23154 > > + */ > > + __asm __volatile( > > + "nop;nop;nop;nop;nop;nop;nop;nop; \n" > > + "mrs %0, ICC_IAR1_EL1 \n" > > + "nop;nop;nop;nop; \n" > > + "dsb sy \n" > > + : "=&r" (active_irq)); > > + } else { > > + active_irq = gic_icc_read(IAR1); > > + } > > + > > + if (__predict_false(active_irq >= sc->gic_nirqs)) > > + return (FILTER_HANDLED); > > > > IMHO this is not true. Active IRQ could be much bigger than number of > supported IRQs. We are asking for debugging in the future when we > enable ITS. It is correct, the ITS change to this file is missing so we are unable to enable ITS interrupts. ... > > + > > +#ifdef FDT > > +static int > > +gic_map_fdt(device_t dev, u_int ncells, pcell_t *cells, u_int > > *irqp, > > + enum intr_polarity *polp, enum intr_trigger *trigp) > > > > All other functions are called gic_v3 and this one is just gic_ > Why can't we move as much FDT code to the dedicated file which is > gic_v3_fdt.c? Unfortunately due to the current code in subr_intr.c this is needed for simplicity. It it my understanding there is work to fix this, so for now I would prefer to keep this. ... > > + /* Set the trigger and polarity */ > > + if (irq <= GIC_LAST_PPI) > > + reg = gic_r_read(sc, 4, > > + GICR_SGI_BASE_SIZE + GICD_ICFGR(irq)); > > + else > > + reg = gic_d_read(sc, 4, GICD_ICFGR(irq)); > > + if (trig == INTR_TRIGGER_LEVEL) > > + reg &= ~(2 << ((irq % 16) * 2)); > > + else > > + reg |= 2 << ((irq % 16) * 2); > > > > The rule of not using magic numbers does not apply here ;-) ? This is partially why this is still disabled by default, the code still needs a little polish, however it will be needed to help with a future review for changes to subr_intr.c. ... > > +static void > > +gic_v3_disable_intr(device_t dev, struct intr_irqsrc *isrc) > > +{ > > + struct gic_v3_softc *sc; > > + struct gic_v3_irqsrc *gi; > > + u_int irq; > > + > > + sc = device_get_softc(dev); > > + gi = (struct gic_v3_irqsrc *)isrc; > > + irq = gi->gi_irq; > > + > > + if (irq <= GIC_LAST_PPI) { > > + /* SGIs and PPIs in corresponding Re-Distributor */ > > + gic_r_write(sc, 4, GICR_SGI_BASE_SIZE + > > GICD_ICENABLER(irq), > > + GICD_I_MASK(irq)); > > + gic_v3_wait_for_rwp(sc, REDIST); > > + } else if (irq >= GIC_FIRST_SPI && irq <= GIC_LAST_SPI) { > > + /* SPIs in distributor */ > > + gic_d_write(sc, 4, GICD_ICENABLER(irq), > > GICD_I_MASK(irq)); > > + gic_v3_wait_for_rwp(sc, DIST); > > > > In gic_v3_setup_intr() we need spin lock and here we don't ? The locking was based on the existing intrng gic driver, I think they are both bogus. ... > > +static void > > +gic_v3_ipi_send(device_t dev, struct intr_irqsrc *isrc, cpuset_t > > cpus, > > + u_int ipi) > > > > What exactly is the functional difference between the current > implementation and this one? > Maybe we should exchange an old one to this or the opposite way > instead of having two different implementations? This one only needs to loop through the list of cpus once. In the common case I would expect this to be optimal as FreeBSD cpuids will align with the hardware clusters so a contiguous groups of CPUs will be on a single cluster. The only hardware I know where this isn't the case is the ARM Juno where we boot on hardware CPU 2. > > > > +{ > > + struct gic_v3_irqsrc *gi = (struct gic_v3_irqsrc *)isrc; > > + uint64_t aff, val, irq; > > + int i; > > + > > +#define GIC_AFF_MASK (CPU_AFF3_MASK | CPU_AFF2_MASK | > > CPU_AFF1_MASK) > > +#define GIC_AFFINITY(i) (CPU_AFFINITY(i) & GIC_AFF_MASK) > > + aff = GIC_AFFINITY(0); > > + irq = gi->gi_irq; > > + val = 0; > > + > > + /* Iterate through all CPUs in set */ > > + for (i = 0; i < mp_ncpus; i++) { > > + /* Move to the next affinity group */ > > + if (aff != GIC_AFFINITY(i)) { > > + /* Send the IPI */ > > + if (val != 0) { > > + gic_icc_write(SGI1R, val); > > + val = 0; > > + } > > + aff = GIC_AFFINITY(i); > > + } > > + > > + /* Send the IPI to this cpu */ > > + if (CPU_ISSET(i, &cpus)) { > > +#define > > ICC_SGI1R_AFFINITY(aff) \ > > + (((uint64_t)CPU_AFF3(aff) << ICC_SGI1R_EL1_AFF3_SHIFT) | \ > > + ((uint64_t)CPU_AFF2(aff) << ICC_SGI1R_EL1_AFF2_SHIFT) | \ > > + ((uint64_t)CPU_AFF1(aff) << ICC_SGI1R_EL1_AFF1_SHIFT)) > > + /* Set the affinity when the first at this > > level */ > > + if (val == 0) > > + val = ICC_SGI1R_AFFINITY(aff) | > > + irq << > > ICC_SGI1R_EL1_SGIID_SHIFT; > > + /* Set the bit to send the IPI to te CPU */ > > + val |= 1 << CPU_AFF0(CPU_AFFINITY(i)); > > + } > > + } > > + > > + /* Send the IPI to the last cpu affinity group */ > > + if (val != 0) > > + gic_icc_write(SGI1R, val); > > +#undef GIC_AFF_MASK > > +#undef GIC_AFFINITY > > > > Couldn't we just use variables instead of defining and undefinining > those ugly macros here? > It really looks like they are here just to look different than it was > in the previous implementation. What's ugly about them? They never change so I'm unsure why a variable is needed. Andrew
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