Re: [PATCH v3 03/14] PCI: rcar: Convert to MSI domains

Lorenzo Pieralisi
2021-04-01T10:21:53Z

On Tue, Mar 30, 2021 at 04:11:34PM +0100, Marc Zyngier wrote:

[...]

> +static void rcar_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
> +{
> + struct rcar_msi *msi = irq_data_get_irq_chip_data(data);
> + unsigned long pa = virt_to_phys(msi);
>
> - hwirq = rcar_msi_alloc_region(msi, nvec);
> - if (hwirq < 0)
> - return -ENOSPC;
> + /* Use the msi structure as the PA for the MSI doorbell */
> + msg->address_lo = lower_32_bits(pa);
> + msg->address_hi = upper_32_bits(pa);

I don't think this change is aligned with the previous patch (is it ?),
the PA address we are using here is different from the one programmed
into the controller registers - either that or I am missing something,
please let me know.

Thanks,
Lorenzo

> + msg->data = data->hwirq;
> +}
>
> - irq = irq_find_mapping(msi->domain, hwirq);
> - if (!irq)
> - return -ENOSPC;
> +static struct irq_chip rcar_msi_bottom_chip = {
> + .name = "Rcar MSI",
> + .irq_ack = rcar_msi_irq_ack,
> + .irq_mask = rcar_msi_irq_mask,
> + .irq_unmask = rcar_msi_irq_unmask,
> + .irq_set_affinity = rcar_msi_set_affinity,
> + .irq_compose_msi_msg = rcar_compose_msi_msg,
> +};
>
> - for (i = 0; i < nvec; i++) {
> - /*
> - * irq_create_mapping() called from rcar_pcie_probe() pre-
> - * allocates descs, so there is no need to allocate descs here.
> - * We can therefore assume that if irq_find_mapping() above
> - * returns non-zero, then the descs are also successfully
> - * allocated.
> - */
> - if (irq_set_msi_desc_off(irq, i, desc)) {
> - /* TODO: clear */
> - return -EINVAL;
> - }
> - }
> +static int rcar_msi_domain_alloc(struct irq_domain *domain, unsigned int virq,
> + unsigned int nr_irqs, void *args)
> +{
> + struct rcar_msi *msi = domain->host_data;
> + unsigned int i;
> + int hwirq;
> +
> + mutex_lock(&msi->map_lock);
>
> - desc->nvec_used = nvec;
> - desc->msi_attrib.multiple = order_base_2(nvec);
> + hwirq = bitmap_find_free_region(msi->used, INT_PCI_MSI_NR, order_base_2(nr_irqs));
>
> - msg.address_lo = rcar_pci_read_reg(pcie, PCIEMSIALR) & ~MSIFE;
> - msg.address_hi = rcar_pci_read_reg(pcie, PCIEMSIAUR);
> - msg.data = hwirq;
> + mutex_unlock(&msi->map_lock);
> +
> + if (hwirq < 0)
> + return -ENOSPC;
>
> - pci_write_msi_msg(irq, &msg);
> + for (i = 0; i < nr_irqs; i++)
> + irq_domain_set_info(domain, virq + i, hwirq + i,
> + &rcar_msi_bottom_chip, domain->host_data,
> + handle_edge_irq, NULL, NULL);
>
> return 0;
> }
>
> -static void rcar_msi_teardown_irq(struct msi_controller *chip, unsigned int irq)
> +static void rcar_msi_domain_free(struct irq_domain *domain, unsigned int virq,
> + unsigned int nr_irqs)
> {
> - struct rcar_msi *msi = to_rcar_msi(chip);
> - struct irq_data *d = irq_get_irq_data(irq);
> + struct irq_data *d = irq_domain_get_irq_data(domain, virq);
> + struct rcar_msi *msi = domain->host_data;
>
> - rcar_msi_free(msi, d->hwirq);
> -}
> -
> -static struct irq_chip rcar_msi_irq_chip = {
> - .name = "R-Car PCIe MSI",
> - .irq_enable = pci_msi_unmask_irq,
> - .irq_disable = pci_msi_mask_irq,
> - .irq_mask = pci_msi_mask_irq,
> - .irq_unmask = pci_msi_unmask_irq,
> -};
> + mutex_lock(&msi->map_lock);
>
> -static int rcar_msi_map(struct irq_domain *domain, unsigned int irq,
> - irq_hw_number_t hwirq)
> -{
> - irq_set_chip_and_handler(irq, &rcar_msi_irq_chip, handle_simple_irq);
> - irq_set_chip_data(irq, domain->host_data);
> + bitmap_release_region(msi->used, d->hwirq, order_base_2(nr_irqs));
>
> - return 0;
> + mutex_unlock(&msi->map_lock);
> }
>
> -static const struct irq_domain_ops msi_domain_ops = {
> - .map = rcar_msi_map,
> +static const struct irq_domain_ops rcar_msi_domain_ops = {
> + .alloc = rcar_msi_domain_alloc,
> + .free = rcar_msi_domain_free,
> +};
> +
> +static struct msi_domain_info rcar_msi_info = {
> + .flags = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
> + MSI_FLAG_MULTI_PCI_MSI),
> + .chip = &rcar_msi_top_chip,
> };
>
> -static void rcar_pcie_unmap_msi(struct rcar_pcie_host *host)
> +static int rcar_allocate_domains(struct rcar_msi *msi)
> {
> - struct rcar_msi *msi = &host->msi;
> - int i, irq;
> + struct rcar_pcie *pcie = &msi_to_host(msi)->pcie;
> + struct fwnode_handle *fwnode = dev_fwnode(pcie->dev);
> + struct irq_domain *parent;
> +
> + parent = irq_domain_create_linear(fwnode, INT_PCI_MSI_NR,
> + &rcar_msi_domain_ops, msi);
> + if (!parent) {
> + dev_err(pcie->dev, "failed to create IRQ domain\n");
> + return -ENOMEM;
> + }
> + irq_domain_update_bus_token(parent, DOMAIN_BUS_NEXUS);
>
> - for (i = 0; i < INT_PCI_MSI_NR; i++) {
> - irq = irq_find_mapping(msi->domain, i);
> - if (irq > 0)
> - irq_dispose_mapping(irq);
> + msi->domain = pci_msi_create_irq_domain(fwnode, &rcar_msi_info, parent);
> + if (!msi->domain) {
> + dev_err(pcie->dev, "failed to create MSI domain\n");
> + irq_domain_remove(parent);
> + return -ENOMEM;
> }
>
> - irq_domain_remove(msi->domain);
> + return 0;
> }
>
> -static void rcar_pcie_hw_enable_msi(struct rcar_pcie_host *host)
> +static void rcar_free_domains(struct rcar_msi *msi)
> {
> - struct rcar_pcie *pcie = &host->pcie;
> - struct device *dev = pcie->dev;
> - struct resource res;
> + struct irq_domain *parent = msi->domain->parent;
>
> - if (WARN_ON(of_address_to_resource(dev->of_node, 0, &res)))
> - return;
> -
> - /* setup MSI data target */
> - rcar_pci_write_reg(pcie, lower_32_bits(res.start) | MSIFE, PCIEMSIALR);
> - rcar_pci_write_reg(pcie, upper_32_bits(res.start), PCIEMSIAUR);
> -
> - /* enable all MSI interrupts */
> - rcar_pci_write_reg(pcie, 0xffffffff, PCIEMSIIER);
> + irq_domain_remove(msi->domain);
> + irq_domain_remove(parent);
> }
>
> static int rcar_pcie_enable_msi(struct rcar_pcie_host *host)
> @@ -698,29 +675,24 @@ static int rcar_pcie_enable_msi(struct rcar_pcie_host *host)
> struct rcar_pcie *pcie = &host->pcie;
> struct device *dev = pcie->dev;
> struct rcar_msi *msi = &host->msi;
> - int err, i;
> -
> - mutex_init(&msi->lock);
> + struct resource res;
> + int err;
>
> - msi->chip.dev = dev;
> - msi->chip.setup_irq = rcar_msi_setup_irq;
> - msi->chip.setup_irqs = rcar_msi_setup_irqs;
> - msi->chip.teardown_irq = rcar_msi_teardown_irq;
> + mutex_init(&msi->map_lock);
> + spin_lock_init(&msi->mask_lock);
>
> - msi->domain = irq_domain_add_linear(dev->of_node, INT_PCI_MSI_NR,
> - &msi_domain_ops, &msi->chip);
> - if (!msi->domain) {
> - dev_err(dev, "failed to create IRQ domain\n");
> - return -ENOMEM;
> - }
> + err = of_address_to_resource(dev->of_node, 0, &res);
> + if (err)
> + return err;
>
> - for (i = 0; i < INT_PCI_MSI_NR; i++)
> - irq_create_mapping(msi->domain, i);
> + err = rcar_allocate_domains(msi);
> + if (err)
> + return err;
>
> /* Two irqs are for MSI, but they are also used for non-MSI irqs */
> err = devm_request_irq(dev, msi->irq1, rcar_pcie_msi_irq,
> IRQF_SHARED | IRQF_NO_THREAD,
> - rcar_msi_irq_chip.name, host);
> + rcar_msi_bottom_chip.name, host);
> if (err < 0) {
> dev_err(dev, "failed to request IRQ: %d\n", err);
> goto err;
> @@ -728,19 +700,26 @@ static int rcar_pcie_enable_msi(struct rcar_pcie_host *host)
>
> err = devm_request_irq(dev, msi->irq2, rcar_pcie_msi_irq,
> IRQF_SHARED | IRQF_NO_THREAD,
> - rcar_msi_irq_chip.name, host);
> + rcar_msi_bottom_chip.name, host);
> if (err < 0) {
> dev_err(dev, "failed to request IRQ: %d\n", err);
> goto err;
> }
>
> - /* setup MSI data target */
> - rcar_pcie_hw_enable_msi(host);
> + /* disable all MSIs */
> + rcar_pci_write_reg(pcie, 0, PCIEMSIIER);
> +
> + /*
> + * Setup MSI data target using RC base address address, which
> + * is guaranteed to be in the low 32bit range on any RCar HW.
> + */
> + rcar_pci_write_reg(pcie, lower_32_bits(res.start) | MSIFE, PCIEMSIALR);
> + rcar_pci_write_reg(pcie, upper_32_bits(res.start), PCIEMSIAUR);
>
> return 0;
>
> err:
> - rcar_pcie_unmap_msi(host);
> + rcar_free_domains(msi);
> return err;
> }
>
> @@ -754,7 +733,7 @@ static void rcar_pcie_teardown_msi(struct rcar_pcie_host *host)
> /* Disable address decoding of the MSI interrupt, MSIFE */
> rcar_pci_write_reg(pcie, 0, PCIEMSIALR);
>
> - rcar_pcie_unmap_msi(host);
> + rcar_free_domains(&host->msi);
> }
>
> static int rcar_pcie_get_resources(struct rcar_pcie_host *host)
> @@ -1007,8 +986,17 @@ static int __maybe_unused rcar_pcie_resume(struct device *dev)
> dev_info(dev, "PCIe x%d: link up\n", (data >> 20) & 0x3f);
>
> /* Enable MSI */
> - if (IS_ENABLED(CONFIG_PCI_MSI))
> - rcar_pcie_hw_enable_msi(host);
> + if (IS_ENABLED(CONFIG_PCI_MSI)) {
> + struct resource res;
> + u32 val;
> +
> + of_address_to_resource(dev->of_node, 0, &res);
> + rcar_pci_write_reg(pcie, upper_32_bits(res.start), PCIEMSIAUR);
> + rcar_pci_write_reg(pcie, lower_32_bits(res.start) | MSIFE, PCIEMSIALR);
> +
> + bitmap_to_arr32(&val, host->msi.used, INT_PCI_MSI_NR);
> + rcar_pci_write_reg(pcie, val, PCIEMSIIER);
> + }
>
> rcar_pcie_hw_enable(host);
>
> --
> 2.29.2
>