[PATCH v3 3/5] pci: altera: Add Altera PCIe MSI driver
Ley Foon Tan
lftan at altera.com
Mon Aug 10 04:00:44 PDT 2015
On Fri, Aug 7, 2015 at 10:44 PM, Marc Zyngier <marc.zyngier at arm.com> wrote:
> On 07/08/15 08:43, Ley Foon Tan wrote:
>> This patch adds Altera PCIe MSI driver. This soft IP supports configurable
>> number of vectors, which is a dts parameter.
>>
>> Signed-off-by: Ley Foon Tan <lftan at altera.com>
>> ---
>> drivers/pci/host/Kconfig | 8 +
>> drivers/pci/host/Makefile | 1 +
>> drivers/pci/host/pcie-altera-msi.c | 309 +++++++++++++++++++++++++++++++++++++
>> 3 files changed, 318 insertions(+)
>> create mode 100644 drivers/pci/host/pcie-altera-msi.c
>>
<snip>
>> +static int altera_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
>> + unsigned int nr_irqs, void *args)
>> +{
>> + struct altera_msi *msi = domain->host_data;
>> + unsigned long bit;
>> + u32 mask;
>> +
>
> As you cannot support multi-MSI, it would be good to have a
> WARN_ON(nr_irqs != 1) here. Just in case...
Noted.
>
>> + mutex_lock(&msi->lock);
>> +
>> + bit = find_first_zero_bit(msi->used, msi->num_of_vectors);
>> + if (bit >= msi->num_of_vectors)
>> + return -ENOSPC;
>> +
>> + set_bit(bit, msi->used);
>> +
>> + mutex_unlock(&msi->lock);
>> +
>> + irq_domain_set_info(domain, virq, bit, &altera_msi_bottom_irq_chip,
>> + domain->host_data, handle_simple_irq,
>> + NULL, NULL);
>> + set_irq_flags(virq, IRQF_VALID);
>> +
>> + mask = msi_readl(msi, MSI_INTMASK);
>> + mask |= 1 << bit;
>> + msi_writel(msi, mask, MSI_INTMASK);
>> +
>> + return 0;
>> +}
>> +
>> +static void altera_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 altera_msi *msi = irq_data_get_irq_chip_data(d);
>> + u32 mask;
>> +
>> + mutex_lock(&msi->lock);
>> +
>> + if (!test_bit(d->hwirq, msi->used)) {
>> + dev_err(&msi->pdev->dev, "trying to free unused MSI#%lu\n",
>> + d->hwirq);
>> + } else {
>> + __clear_bit(d->hwirq, msi->used);
>> + mask = msi_readl(msi, MSI_INTMASK);
>> + mask &= ~(1 << d->hwirq);
>> + msi_writel(msi, mask, MSI_INTMASK);
>> + }
>> +
>> + mutex_unlock(&msi->lock);
>> +}
>> +
>> +static const struct irq_domain_ops msi_domain_ops = {
>> + .alloc = altera_irq_domain_alloc,
>> + .free = altera_irq_domain_free,
>> +};
>> +
>> +static int altera_allocate_domains(struct altera_msi *msi)
>> +{
>> + msi->inner_domain = irq_domain_add_linear(NULL, msi->num_of_vectors,
>> + &msi_domain_ops, msi);
>> + if (!msi->inner_domain) {
>> + dev_err(&msi->pdev->dev, "failed to create IRQ domain\n");
>> + return -ENOMEM;
>> + }
>> +
>> + msi->msi_domain = pci_msi_create_irq_domain(msi->pdev->dev.of_node,
>> + &altera_msi_domain_info, msi->inner_domain);
>> + if (!msi->msi_domain) {
>> + dev_err(&msi->pdev->dev, "failed to create MSI domain\n");
>> + irq_domain_remove(msi->inner_domain);
>> + return -ENOMEM;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static void altera_free_domains(struct altera_msi *msi)
>> +{
>> + irq_domain_remove(msi->msi_domain);
>> + irq_domain_remove(msi->inner_domain);
>> +}
>> +
>> +static int altera_msi_remove(struct platform_device *pdev)
>> +{
>> + struct altera_msi *msi = platform_get_drvdata(pdev);
>> +
>> + msi_writel(msi, 0, MSI_INTMASK);
>> + irq_set_chained_handler(msi->irq, NULL);
>> + irq_set_handler_data(msi->irq, NULL);
>> +
>> + altera_free_domains(msi);
>> +
>> + platform_set_drvdata(pdev, NULL);
>> + return 0;
>> +}
>> +
>> +static int altera_msi_probe(struct platform_device *pdev)
>> +{
>> + struct altera_msi *msi;
>> + struct device_node *np = pdev->dev.of_node;
>> + struct resource *res;
>> + int ret;
>> +
>> + msi = devm_kzalloc(&pdev->dev, sizeof(struct altera_msi),
>> + GFP_KERNEL);
>> + if (!msi)
>> + return -ENOMEM;
>> +
>> + mutex_init(&msi->lock);
>> + msi->pdev = pdev;
>> +
>> + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "csr");
>
> Error checking here.
Noted.
>
>> + msi->csr_base = devm_ioremap_resource(&pdev->dev, res);
>> + if (IS_ERR(msi->csr_base)) {
>> + dev_err(&pdev->dev, "get csr resource failed\n");
>> + return PTR_ERR(msi->csr_base);
>> + }
>> +
>> + res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
>> + "vector_slave");
>
> And here.
Noted.
>
>> + msi->vector_base = devm_ioremap_resource(&pdev->dev, res);
>> + if (IS_ERR(msi->vector_base)) {
>> + dev_err(&pdev->dev, "get vector slave resource failed\n");
>> + return PTR_ERR(msi->vector_base);
>> + }
>> +
>> + msi->vector_phy = res->start;
>> +
>> + if (of_property_read_u32(np, "num-vectors", &msi->num_of_vectors)) {
>> + dev_err(&pdev->dev, "failed to parse the number of vectors\n");
>> + return -EINVAL;
>> + }
>> +
>> + ret = altera_allocate_domains(msi);
>> + if (ret)
>> + return ret;
>> +
>> + msi->irq = platform_get_irq(pdev, 0);
>> + if (msi->irq <= 0) {
>> + dev_err(&pdev->dev, "failed to map IRQ: %d\n", msi->irq);
>> + ret = -ENODEV;
>> + goto err;
>> + }
>> +
>> + irq_set_chained_handler_and_data(msi->irq, altera_msi_isr, msi);
>> + platform_set_drvdata(pdev, msi);
>> +
>> + return 0;
>> +
>> +err:
>> + altera_msi_remove(pdev);
>> + return ret;
>> +}
>> +
>> +static const struct of_device_id altera_msi_of_match[] = {
>> + { .compatible = "altr,msi-1.0", NULL },
>> + { },
>> +};
>> +
>> +static struct platform_driver altera_msi_driver = {
>> + .driver = {
>> + .name = "altera-msi",
>> + .of_match_table = altera_msi_of_match,
>> + },
>> + .probe = altera_msi_probe,
>> + .remove = altera_msi_remove,
>> +};
>> +
>> +static int __init altera_msi_init(void)
>> +{
>> + return platform_driver_register(&altera_msi_driver);
>> +}
>> +
>> +subsys_initcall(altera_msi_init);
>> +
>> +MODULE_AUTHOR("Ley Foon Tan <lftan at altera.com>");
>> +MODULE_DESCRIPTION("Altera PCIe MSI support");
>> +MODULE_LICENSE("GPL v2");
>> --
>> 1.8.2.1
>>
>
> Apart from the couple of nits above, this is starting to look good too.
> And as for the PCIe driver, you need to get the DT maintainers to review
> that part.
Okay, added DT maintainers to CC list.
Thanks for reviewing.
Regards
Ley Foon
More information about the linux-arm-kernel
mailing list