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Message-ID: <54857028.2010707@arm.com>
Date: Mon, 08 Dec 2014 09:32:24 +0000
From: Marc Zyngier <marc.zyngier@....com>
To: "Yun Wu (Abel)" <wuyun.wu@...wei.com>
CC: Thomas Gleixner <tglx@...utronix.de>,
Jason Cooper <jason@...edaemon.net>,
"linux-arm-kernel@...ts.infradead.org"
<linux-arm-kernel@...ts.infradead.org>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
Jiang Liu <jiang.liu@...ux.intel.com>,
Bjorn Helgaas <bhelgaas@...gle.com>,
Yingjoe Chen <yingjoe.chen@...iatek.com>,
Will Deacon <Will.Deacon@....com>,
Catalin Marinas <Catalin.Marinas@....com>,
Mark Rutland <Mark.Rutland@....com>,
"suravee.suthikulpanit@....com" <suravee.suthikulpanit@....com>,
Robert Richter <robert.richter@...iumnetworks.com>
Subject: Re: [PATCH v3 09/13] irqchip: GICv3: ITS: MSI support
On 08/12/14 03:28, Yun Wu (Abel) wrote:
> Hi Marc,
> On 2014/11/24 22:35, Marc Zyngier wrote:
>
>> Now, the bit of code that allow us to use the ITS as a MSI controller.
>> Both MSI and MSI-X are supported.
>>
>> Signed-off-by: Marc Zyngier <marc.zyngier@....com>
>> ---
>> drivers/irqchip/irq-gic-v3-its.c | 176 +++++++++++++++++++++++++++++++++++++
>> include/linux/irqchip/arm-gic-v3.h | 6 ++
>> 2 files changed, 182 insertions(+)
>>
>> diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
>> index d687fd4..532c6df 100644
>> --- a/drivers/irqchip/irq-gic-v3-its.c
>> +++ b/drivers/irqchip/irq-gic-v3-its.c
>> @@ -587,12 +587,47 @@ static int its_set_affinity(struct irq_data *d, const struct cpumask *mask_val,
>> return IRQ_SET_MASK_OK_DONE;
>> }
>>
>> +static void its_irq_compose_msi_msg(struct irq_data *d, struct msi_msg *msg)
>> +{
>> + struct its_device *its_dev = irq_data_get_irq_chip_data(d);
>> + struct its_node *its;
>> + u64 addr;
>> +
>> + its = its_dev->its;
>> + addr = its->phys_base + GITS_TRANSLATER;
>> +
>> + msg->address_lo = addr & ((1UL << 32) - 1);
>> + msg->address_hi = addr >> 32;
>> + msg->data = its_get_event_id(d);
>> +}
>> +
>> static struct irq_chip its_irq_chip = {
>> .name = "ITS",
>> .irq_mask = its_mask_irq,
>> .irq_unmask = its_unmask_irq,
>> .irq_eoi = its_eoi_irq,
>> .irq_set_affinity = its_set_affinity,
>> + .irq_compose_msi_msg = its_irq_compose_msi_msg,
>> +};
>> +
>> +static void its_mask_msi_irq(struct irq_data *d)
>> +{
>> + pci_msi_mask_irq(d);
>> + irq_chip_mask_parent(d);
>> +}
>> +
>> +static void its_unmask_msi_irq(struct irq_data *d)
>> +{
>> + pci_msi_unmask_irq(d);
>> + irq_chip_unmask_parent(d);
>> +}
>> +
>> +static struct irq_chip its_msi_irq_chip = {
>> + .name = "ITS-MSI",
>> + .irq_unmask = its_unmask_msi_irq,
>> + .irq_mask = its_mask_msi_irq,
>> + .irq_eoi = irq_chip_eoi_parent,
>> + .irq_write_msi_msg = pci_msi_domain_write_msg,
>> };
>>
>> /*
>> @@ -1055,3 +1090,144 @@ static void its_free_device(struct its_device *its_dev)
>> kfree(its_dev->itt);
>> kfree(its_dev);
>> }
>> +
>> +static int its_alloc_device_irq(struct its_device *dev, irq_hw_number_t *hwirq)
>> +{
>> + int idx;
>> +
>> + idx = find_first_zero_bit(dev->lpi_map, dev->nr_lpis);
>> + if (idx == dev->nr_lpis)
>> + return -ENOSPC;
>> +
>> + *hwirq = dev->lpi_base + idx;
>> + set_bit(idx, dev->lpi_map);
>> +
>> + /* Map the GIC irq ID to the device */
>> + its_send_mapvi(dev, *hwirq, idx);
>
> It would be better if we do hardware-level initialization in domain.{activate,deactivate}.
That'd certainly be possible. I'll have a look.
>> +
>> + return 0;
>> +}
>> +
>> +static int its_msi_prepare(struct irq_domain *domain, struct device *dev,
>> + int nvec, msi_alloc_info_t *info)
>> +{
>> + struct pci_dev *pdev;
>> + struct its_node *its;
>> + u32 dev_id;
>> + struct its_device *its_dev;
>> +
>> + if (!dev_is_pci(dev))
>> + return -EINVAL;
>> +
>> + pdev = to_pci_dev(dev);
>> + dev_id = PCI_DEVID(pdev->bus->number, pdev->devfn);
>> + its = domain->parent->host_data;
>> +
>> + its_dev = its_find_device(its, dev_id);
>> + if (WARN_ON(its_dev))
>> + return -EINVAL;
>> +
>> + its_dev = its_create_device(its, dev_id, nvec);
>> + if (!its_dev)
>> + return -ENOMEM;
>> +
>> + dev_dbg(&pdev->dev, "ITT %d entries, %d bits\n", nvec, ilog2(nvec));
>> +
>> + info->scratchpad[0].ptr = its_dev;
>> + info->scratchpad[1].ptr = dev;
>> + return 0;
>> +}
>> +
>> +static struct msi_domain_ops its_pci_msi_ops = {
>> + .msi_prepare = its_msi_prepare,
>> +};
>> +
>> +static struct msi_domain_info its_pci_msi_domain_info = {
>> + .flags = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
>> + MSI_FLAG_MULTI_PCI_MSI | MSI_FLAG_PCI_MSIX),
>> + .ops = &its_pci_msi_ops,
>> + .chip = &its_msi_irq_chip,
>> +};
>> +
>> +static int its_irq_gic_domain_alloc(struct irq_domain *domain,
>> + unsigned int virq,
>> + irq_hw_number_t hwirq)
>> +{
>> + struct of_phandle_args args;
>> +
>> + args.np = domain->parent->of_node;
>> + args.args_count = 3;
>> + args.args[0] = GIC_IRQ_TYPE_LPI;
>> + args.args[1] = hwirq;
>> + args.args[2] = IRQ_TYPE_EDGE_RISING;
>> +
>> + return irq_domain_alloc_irqs_parent(domain, virq, 1, &args);
>> +}
>> +
>> +static int its_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
>> + unsigned int nr_irqs, void *args)
>> +{
>> + msi_alloc_info_t *info = args;
>> + struct its_device *its_dev = info->scratchpad[0].ptr;
>> + irq_hw_number_t hwirq;
>> + int err;
>> + int i;
>> +
>> + for (i = 0; i < nr_irqs; i++) {
>> + err = its_alloc_device_irq(its_dev, &hwirq);
>> + if (err)
>> + return err;
>> +
>> + err = its_irq_gic_domain_alloc(domain, virq + i, hwirq);
>> + if (err)
>> + return err;
>> +
>> + irq_domain_set_hwirq_and_chip(domain, virq + i,
>> + hwirq, &its_irq_chip, its_dev);
>> + dev_dbg(info->scratchpad[1].ptr, "ID:%d pID:%d vID:%d\n",
>> + (int)(hwirq - its_dev->lpi_base), (int)hwirq, virq + i);
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static void its_irq_domain_free(struct irq_domain *domain, unsigned int virq,
>> + unsigned int nr_irqs)
>> +{
>> + struct irq_data *d = irq_domain_get_irq_data(domain, virq);
>> + struct its_device *its_dev = irq_data_get_irq_chip_data(d);
>> + int i;
>> +
>> + for (i = 0; i < nr_irqs; i++) {
>> + struct irq_data *data = irq_domain_get_irq_data(domain,
>> + virq + i);
>> + int event = its_get_event_id(data);
>> +
>> + /* Stop the delivery of interrupts */
>> + its_send_discard(its_dev, event);
>> +
>> + /* Mark interrupt index as unused */
>> + clear_bit(event, its_dev->lpi_map);
>> +
>> + /* Nuke the entry in the domain */
>> + irq_domain_reset_irq_data(d);
>
> I think you mean "data" here, instead of "d"?
Indeed, nice catch.
Thanks,
M.
--
Jazz is not dead. It just smells funny...
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