| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * Altera PCIe MSI support |
| * |
| * Author: Ley Foon Tan <lftan@altera.com> |
| * |
| * Copyright Altera Corporation (C) 2013-2015. All rights reserved |
| */ |
| |
| #include <linux/interrupt.h> |
| #include <linux/irqchip/chained_irq.h> |
| #include <linux/init.h> |
| #include <linux/msi.h> |
| #include <linux/of_address.h> |
| #include <linux/of_irq.h> |
| #include <linux/of_pci.h> |
| #include <linux/pci.h> |
| #include <linux/platform_device.h> |
| #include <linux/slab.h> |
| |
| #define MSI_STATUS 0x0 |
| #define MSI_ERROR 0x4 |
| #define MSI_INTMASK 0x8 |
| |
| #define MAX_MSI_VECTORS 32 |
| |
| struct altera_msi { |
| DECLARE_BITMAP(used, MAX_MSI_VECTORS); |
| struct mutex lock; /* protect "used" bitmap */ |
| struct platform_device *pdev; |
| struct irq_domain *msi_domain; |
| struct irq_domain *inner_domain; |
| void __iomem *csr_base; |
| void __iomem *vector_base; |
| phys_addr_t vector_phy; |
| u32 num_of_vectors; |
| int irq; |
| }; |
| |
| static inline void msi_writel(struct altera_msi *msi, const u32 value, |
| const u32 reg) |
| { |
| writel_relaxed(value, msi->csr_base + reg); |
| } |
| |
| static inline u32 msi_readl(struct altera_msi *msi, const u32 reg) |
| { |
| return readl_relaxed(msi->csr_base + reg); |
| } |
| |
| static void altera_msi_isr(struct irq_desc *desc) |
| { |
| struct irq_chip *chip = irq_desc_get_chip(desc); |
| struct altera_msi *msi; |
| unsigned long status; |
| u32 bit; |
| u32 virq; |
| |
| chained_irq_enter(chip, desc); |
| msi = irq_desc_get_handler_data(desc); |
| |
| while ((status = msi_readl(msi, MSI_STATUS)) != 0) { |
| for_each_set_bit(bit, &status, msi->num_of_vectors) { |
| /* Dummy read from vector to clear the interrupt */ |
| readl_relaxed(msi->vector_base + (bit * sizeof(u32))); |
| |
| virq = irq_find_mapping(msi->inner_domain, bit); |
| if (virq) |
| generic_handle_irq(virq); |
| else |
| dev_err(&msi->pdev->dev, "unexpected MSI\n"); |
| } |
| } |
| |
| chained_irq_exit(chip, desc); |
| } |
| |
| static struct irq_chip altera_msi_irq_chip = { |
| .name = "Altera PCIe MSI", |
| .irq_mask = pci_msi_mask_irq, |
| .irq_unmask = pci_msi_unmask_irq, |
| }; |
| |
| static struct msi_domain_info altera_msi_domain_info = { |
| .flags = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS | |
| MSI_FLAG_PCI_MSIX), |
| .chip = &altera_msi_irq_chip, |
| }; |
| |
| static void altera_compose_msi_msg(struct irq_data *data, struct msi_msg *msg) |
| { |
| struct altera_msi *msi = irq_data_get_irq_chip_data(data); |
| phys_addr_t addr = msi->vector_phy + (data->hwirq * sizeof(u32)); |
| |
| msg->address_lo = lower_32_bits(addr); |
| msg->address_hi = upper_32_bits(addr); |
| msg->data = data->hwirq; |
| |
| dev_dbg(&msi->pdev->dev, "msi#%d address_hi %#x address_lo %#x\n", |
| (int)data->hwirq, msg->address_hi, msg->address_lo); |
| } |
| |
| static int altera_msi_set_affinity(struct irq_data *irq_data, |
| const struct cpumask *mask, bool force) |
| { |
| return -EINVAL; |
| } |
| |
| static struct irq_chip altera_msi_bottom_irq_chip = { |
| .name = "Altera MSI", |
| .irq_compose_msi_msg = altera_compose_msi_msg, |
| .irq_set_affinity = altera_msi_set_affinity, |
| }; |
| |
| 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; |
| |
| WARN_ON(nr_irqs != 1); |
| mutex_lock(&msi->lock); |
| |
| bit = find_first_zero_bit(msi->used, msi->num_of_vectors); |
| if (bit >= msi->num_of_vectors) { |
| mutex_unlock(&msi->lock); |
| 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); |
| |
| 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) |
| { |
| struct fwnode_handle *fwnode = of_node_to_fwnode(msi->pdev->dev.of_node); |
| |
| 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(fwnode, |
| &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"); |
| msi->csr_base = devm_ioremap_resource(&pdev->dev, res); |
| if (IS_ERR(msi->csr_base)) { |
| dev_err(&pdev->dev, "failed to map csr memory\n"); |
| return PTR_ERR(msi->csr_base); |
| } |
| |
| res = platform_get_resource_byname(pdev, IORESOURCE_MEM, |
| "vector_slave"); |
| msi->vector_base = devm_ioremap_resource(&pdev->dev, res); |
| if (IS_ERR(msi->vector_base)) { |
| dev_err(&pdev->dev, "failed to map vector_slave memory\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 = msi->irq; |
| 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); |