Hi Thomas,
Thank you for the review!
On 10/28/24 22:06, Thomas Gleixner wrote:
> On Fri, Oct 25 2024 at 15:45, Stanimir Varbanov wrote:
>
>> Add an interrupt controller driver for MSI-X Interrupt Peripheral (MIP)
>> hardware block found in bcm2712. The interrupt controller is used to
>> handle MSI-X interrupts from peripherials behind PCIe endpoints like
>> RP1 south bridge found in RPi5.
>>
>> There are two MIPs on bcm2712, the first has 64 consecutive SPIs
>> assigned to 64 output vectors, and the second has 17 SPIs, but only
>> 8 of them are consecutive starting at the 8th output vector.
>
> This starts to converge nicely. Just a few remaining nitpicks.
>
>> +static int mip_alloc_hwirq(struct mip_priv *mip, unsigned int nr_irqs,
>> + unsigned int *hwirq)
>> +{
>> + int bit;
>> +
>> + spin_lock(&mip->lock);
>> + bit = bitmap_find_free_region(mip->bitmap, mip->num_msis,
>> + ilog2(nr_irqs));
>> + spin_unlock(&mip->lock);
>
> This should be
>
> scoped_guard(spinlock, &mip->lock)
> bit = bitmap_find_free_region(mip->bitmap, mip->num_msis, ilog2(nr_irqs));
>
>> + if (bit < 0)
>> + return bit;
>> +
>> + if (hwirq)
>> + *hwirq = bit;
>
> But what's the point of this conditional? The only call site hands in a
> valid pointer, no?
>
>> + return 0;
>
> And therefore the whole thing can be simplified to:
>
> static int mip_alloc_hwirq(struct mip_priv *mip, unsigned int nr_irqs)
> {
> guard(spinlock)(&mip_lock);
> return bitmap_find_free_region(mip->bitmap, mip->num_msis, ilog2(nr_irqs));
> }
>
> and the callsite becomes:
>
> irq = mip_alloc_hwirq(mip, nr_irqs);
> if (irq < 0)
> return irq;
> Hmm?
>
>> +}
>> +
>> +static void mip_free_hwirq(struct mip_priv *mip, unsigned int hwirq,
>> + unsigned int nr_irqs)
>> +{
>> + spin_lock(&mip->lock);
>
> guard(spinlock)(&mip->lock);
Will address the above comments in next version.
>
>> + bitmap_release_region(mip->bitmap, hwirq, ilog2(nr_irqs));
>> + spin_unlock(&mip->lock);
>> +}
>
>> + ret = irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, &fwspec);
>> + if (ret) {
>> + mip_free_hwirq(mip, irq, nr_irqs);
>> + return ret;
>
> goto err_free_hwirq; ?
>
>> + }
>> +
>> + for (i = 0; i < nr_irqs; i++) {
>> + irqd = irq_domain_get_irq_data(domain->parent, virq + i);
>> + irqd->chip->irq_set_type(irqd, IRQ_TYPE_EDGE_RISING);
>> +
>> + ret = irq_domain_set_hwirq_and_chip(domain, virq + i, hwirq + i,
>> + &mip_middle_irq_chip, mip);
>> + if (ret)
>> + goto err_free;
>> +
>> + irqd = irq_get_irq_data(virq + i);
>> + irqd_set_single_target(irqd);
>> + irqd_set_affinity_on_activate(irqd);
>> + }
>> +
>> + return 0;
>> +
>> +err_free:
>> + irq_domain_free_irqs_parent(domain, virq, nr_irqs);
>> + mip_free_hwirq(mip, irq, nr_irqs);
>> + return ret;
>> +}
>> +
>> +static int __init mip_of_msi_init(struct device_node *node,
>> + struct device_node *parent)
>
> No line break required here.
OK.
>
>> +{
>> + struct platform_device *pdev;
>> + struct mip_priv *mip;
>> + int ret;
>> +
>> + pdev = of_find_device_by_node(node);
>> + of_node_put(node);
>> + if (!pdev)
>> + return -EPROBE_DEFER;
>> +
>> + mip = kzalloc(sizeof(*mip), GFP_KERNEL);
>> + if (!mip)
>> + return -ENOMEM;
>> +
>> + spin_lock_init(&mip->lock);
>> + mip->dev = &pdev->dev;
>> +
>> + ret = mip_parse_dt(mip, node);
>> + if (ret)
>> + goto err_priv;
>> +
>> + mip->base = of_iomap(node, 0);
>> + if (!mip->base) {
>> + ret = -ENXIO;
>> + goto err_priv;
>> + }
>> +
>> + mip->bitmap = bitmap_zalloc(mip->num_msis, GFP_KERNEL);
>> + if (!mip->bitmap) {
>> + ret = -ENOMEM;
>> + goto err_base;
>> + }
>> +
>> + /*
>> + * All MSI-X masked in for the host, masked out for the
>> + * VPU, and edge-triggered.
>> + */
>> + writel(0, mip->base + MIP_INT_MASKL_HOST);
>> + writel(0, mip->base + MIP_INT_MASKH_HOST);
>> + writel(~0, mip->base + MIP_INT_MASKL_VPU);
>> + writel(~0, mip->base + MIP_INT_MASKH_VPU);
>> + writel(~0, mip->base + MIP_INT_CFGL_HOST);
>> + writel(~0, mip->base + MIP_INT_CFGH_HOST);
>
> What undoes that in case mpi_init_domains() fails? Or is it harmless? I
> really have no idea what masked in and masked out means here.
It should be harmless, but I could move registers initialization in
mip_init_domains() and fix the comments.
>
>> + dev_dbg(&pdev->dev,
>> + "MIP: MSI-X count: %u, base: %u, offset: %u, msg_addr: %llx\n",
>
> Please move the string up. You have 100 characters width available.
OK.
>
>> + mip->num_msis, mip->msi_base, mip->msi_offset, mip->msg_addr);
>
> Thanks,
>
> tglx
regards,
~Stan
