The MSI controller in Tango supports 256 message-signaled interrupts, and a single doorbell address. Signed-off-by: Marc Gonzalez <marc_gonzalez@xxxxxxxxxxxxxxxx> --- Changes since v0.2 - Support 256 MSIs instead of only 32 - Use spinlock_t instead of struct mutex - Add MSI_FLAG_PCI_MSIX flag IRQs are acked in tango_msi_isr because handle_simple_irq leaves ack, clear, mask and unmask up to the driver. For the same reason, interrupt enable mask is updated from tango_irq_domain_alloc/free. --- drivers/pci/host/pcie-tango.c | 194 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 194 insertions(+) diff --git a/drivers/pci/host/pcie-tango.c b/drivers/pci/host/pcie-tango.c new file mode 100644 index 000000000000..e88850983a1d --- /dev/null +++ b/drivers/pci/host/pcie-tango.c @@ -0,0 +1,194 @@ +#include <linux/module.h> +#include <linux/irqchip/chained_irq.h> +#include <linux/irqdomain.h> +#include <linux/pci-ecam.h> +#include <linux/msi.h> + +#define MSI_MAX 256 + +struct tango_pcie { + DECLARE_BITMAP(bitmap, MSI_MAX); + spinlock_t lock; + void __iomem *mux; + void __iomem *msi_status; + void __iomem *msi_mask; + phys_addr_t msi_doorbell; + struct irq_domain *irq_domain; + struct irq_domain *msi_domain; + int irq; +}; + +/*** MSI CONTROLLER SUPPORT ***/ + +static void dispatch(struct tango_pcie *pcie, unsigned long status, int base) +{ + unsigned int pos, virq; + + for_each_set_bit(pos, &status, 32) { + virq = irq_find_mapping(pcie->irq_domain, base + pos); + generic_handle_irq(virq); + } +} + +static void tango_msi_isr(struct irq_desc *desc) +{ + u32 status; + struct irq_chip *chip = irq_desc_get_chip(desc); + struct tango_pcie *pcie = irq_desc_get_handler_data(desc); + unsigned int base, offset, pos = 0; + + chained_irq_enter(chip, desc); + + while ((pos = find_next_bit(pcie->bitmap, MSI_MAX, pos)) < MSI_MAX) { + base = round_down(pos, 32); + offset = (pos / 32) * 4; + status = readl_relaxed(pcie->msi_status + offset); + writel_relaxed(status, pcie->msi_status + offset); + dispatch(pcie, status, base); + pos = base + 32; + } + + chained_irq_exit(chip, desc); +} + +static struct irq_chip tango_msi_irq_chip = { + .name = "MSI", + .irq_mask = pci_msi_mask_irq, + .irq_unmask = pci_msi_unmask_irq, +}; + +#define USE_DEF_OPS (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS) + +static struct msi_domain_info msi_domain_info = { + .flags = USE_DEF_OPS | MSI_FLAG_PCI_MSIX, + .chip = &tango_msi_irq_chip, +}; + +static void tango_compose_msi_msg(struct irq_data *data, struct msi_msg *msg) +{ + struct tango_pcie *pcie = irq_data_get_irq_chip_data(data); + + msg->address_lo = lower_32_bits(pcie->msi_doorbell); + msg->address_hi = upper_32_bits(pcie->msi_doorbell); + msg->data = data->hwirq; +} + +static int tango_set_affinity(struct irq_data *irq_data, + const struct cpumask *mask, bool force) +{ + return -EINVAL; +} + +static struct irq_chip tango_msi_chip = { + .name = "MSI", + .irq_compose_msi_msg = tango_compose_msi_msg, + .irq_set_affinity = tango_set_affinity, +}; + +static int find_free_msi(struct irq_domain *dom, unsigned int virq) +{ + u32 val; + struct tango_pcie *pcie = dom->host_data; + unsigned int offset, pos; + + pos = find_first_zero_bit(pcie->bitmap, MSI_MAX); + if (pos >= MSI_MAX) + return -ENOSPC; + + offset = (pos / 32) * 4; + val = readl_relaxed(pcie->msi_mask + offset); + writel_relaxed(val | BIT(pos % 32), pcie->msi_mask + offset); + __set_bit(pos, pcie->bitmap); + + irq_domain_set_info(dom, virq, pos, &tango_msi_chip, + dom->host_data, handle_simple_irq, NULL, NULL); + + return 0; +} + +static int tango_irq_domain_alloc(struct irq_domain *dom, + unsigned int virq, unsigned int nr_irqs, void *args) +{ + int err; + struct tango_pcie *pcie = dom->host_data; + + spin_lock(&pcie->lock); + err = find_free_msi(dom, virq); + spin_unlock(&pcie->lock); + + return err; +} + +static void tango_irq_domain_free(struct irq_domain *dom, + unsigned int virq, unsigned int nr_irqs) +{ + u32 val; + struct irq_data *d = irq_domain_get_irq_data(dom, virq); + struct tango_pcie *pcie = irq_data_get_irq_chip_data(d); + unsigned int offset, pos = d->hwirq; + + spin_lock(&pcie->lock); + + offset = (pos / 32) * 4; + val = readl_relaxed(pcie->msi_mask + offset); + writel_relaxed(val & ~BIT(pos % 32), pcie->msi_mask + offset); + __clear_bit(pos, pcie->bitmap); + + spin_unlock(&pcie->lock); +} + +static const struct irq_domain_ops msi_dom_ops = { + .alloc = tango_irq_domain_alloc, + .free = tango_irq_domain_free, +}; + +static int tango_msi_remove(struct platform_device *pdev) +{ + struct tango_pcie *msi = platform_get_drvdata(pdev); + + irq_set_chained_handler_and_data(msi->irq, NULL, NULL); + irq_domain_remove(msi->msi_domain); + irq_domain_remove(msi->irq_domain); + + return 0; +} + +static int tango_msi_probe(struct platform_device *pdev, struct tango_pcie *pcie) +{ + int i, virq; + struct fwnode_handle *fwnode = of_node_to_fwnode(pdev->dev.of_node); + struct irq_domain *msi_dom, *irq_dom; + + spin_lock_init(&pcie->lock); + + for (i = 0; i < MSI_MAX / 32; ++i) + writel_relaxed(0, pcie->msi_mask + i * 4); + + irq_dom = irq_domain_create_linear(fwnode, MSI_MAX, &msi_dom_ops, pcie); + if (!irq_dom) { + pr_err("Failed to create IRQ domain\n"); + return -ENOMEM; + } + + msi_dom = pci_msi_create_irq_domain(fwnode, &msi_domain_info, irq_dom); + if (!msi_dom) { + pr_err("Failed to create MSI domain\n"); + irq_domain_remove(irq_dom); + return -ENOMEM; + } + + virq = platform_get_irq(pdev, 1); + if (virq <= 0) { + pr_err("Failed to map IRQ\n"); + irq_domain_remove(msi_dom); + irq_domain_remove(irq_dom); + return -ENXIO; + } + + pcie->irq_domain = irq_dom; + pcie->msi_domain = msi_dom; + pcie->irq = virq; + irq_set_chained_handler_and_data(virq, tango_msi_isr, pcie); + + return 0; +} -- 2.11.0 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html