// SPDX-License-Identifier: GPL-2.0 /* * Synopsys DesignWare PCIe host controller driver * * Copyright (C) 2013 Samsung Electronics Co., Ltd. * https://www.samsung.com * * Author: Jingoo Han */ #include #include #include #include #include #include #include #include "pcie-designware.h" static struct pci_ops dw_pcie_ops; static struct pci_ops dw_child_pcie_ops; static void dw_msi_ack_irq(struct irq_data *d) { irq_chip_ack_parent(d); } static void dw_msi_mask_irq(struct irq_data *d) { pci_msi_mask_irq(d); irq_chip_mask_parent(d); } static void dw_msi_unmask_irq(struct irq_data *d) { pci_msi_unmask_irq(d); irq_chip_unmask_parent(d); } static struct irq_chip dw_pcie_msi_irq_chip = { .name = "PCI-MSI", .irq_ack = dw_msi_ack_irq, .irq_mask = dw_msi_mask_irq, .irq_unmask = dw_msi_unmask_irq, }; static struct msi_domain_info dw_pcie_msi_domain_info = { .flags = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS | MSI_FLAG_PCI_MSIX | MSI_FLAG_MULTI_PCI_MSI), .chip = &dw_pcie_msi_irq_chip, }; /* MSI int handler */ irqreturn_t dw_handle_msi_irq(struct dw_pcie_rp *pp) { int i, pos; unsigned long val; u32 status, num_ctrls; irqreturn_t ret = IRQ_NONE; struct dw_pcie *pci = to_dw_pcie_from_pp(pp); num_ctrls = pp->num_vectors / MAX_MSI_IRQS_PER_CTRL; for (i = 0; i < num_ctrls; i++) { status = dw_pcie_readl_dbi(pci, PCIE_MSI_INTR0_STATUS + (i * MSI_REG_CTRL_BLOCK_SIZE)); if (!status) continue; ret = IRQ_HANDLED; val = status; pos = 0; while ((pos = find_next_bit(&val, MAX_MSI_IRQS_PER_CTRL, pos)) != MAX_MSI_IRQS_PER_CTRL) { generic_handle_domain_irq(pp->irq_domain, (i * MAX_MSI_IRQS_PER_CTRL) + pos); pos++; } } return ret; } /* Chained MSI interrupt service routine */ static void dw_chained_msi_isr(struct irq_desc *desc) { struct irq_chip *chip = irq_desc_get_chip(desc); struct dw_pcie_rp *pp; chained_irq_enter(chip, desc); pp = irq_desc_get_handler_data(desc); dw_handle_msi_irq(pp); chained_irq_exit(chip, desc); } static void dw_pci_setup_msi_msg(struct irq_data *d, struct msi_msg *msg) { struct dw_pcie_rp *pp = irq_data_get_irq_chip_data(d); struct dw_pcie *pci = to_dw_pcie_from_pp(pp); u64 msi_target; msi_target = (u64)pp->msi_data; msg->address_lo = lower_32_bits(msi_target); msg->address_hi = upper_32_bits(msi_target); msg->data = d->hwirq; dev_dbg(pci->dev, "msi#%d address_hi %#x address_lo %#x\n", (int)d->hwirq, msg->address_hi, msg->address_lo); } static int dw_pci_msi_set_affinity(struct irq_data *d, const struct cpumask *mask, bool force) { return -EINVAL; } static void dw_pci_bottom_mask(struct irq_data *d) { struct dw_pcie_rp *pp = irq_data_get_irq_chip_data(d); struct dw_pcie *pci = to_dw_pcie_from_pp(pp); unsigned int res, bit, ctrl; unsigned long flags; raw_spin_lock_irqsave(&pp->lock, flags); ctrl = d->hwirq / MAX_MSI_IRQS_PER_CTRL; res = ctrl * MSI_REG_CTRL_BLOCK_SIZE; bit = d->hwirq % MAX_MSI_IRQS_PER_CTRL; pp->irq_mask[ctrl] |= BIT(bit); dw_pcie_writel_dbi(pci, PCIE_MSI_INTR0_MASK + res, pp->irq_mask[ctrl]); raw_spin_unlock_irqrestore(&pp->lock, flags); } static void dw_pci_bottom_unmask(struct irq_data *d) { struct dw_pcie_rp *pp = irq_data_get_irq_chip_data(d); struct dw_pcie *pci = to_dw_pcie_from_pp(pp); unsigned int res, bit, ctrl; unsigned long flags; raw_spin_lock_irqsave(&pp->lock, flags); ctrl = d->hwirq / MAX_MSI_IRQS_PER_CTRL; res = ctrl * MSI_REG_CTRL_BLOCK_SIZE; bit = d->hwirq % MAX_MSI_IRQS_PER_CTRL; pp->irq_mask[ctrl] &= ~BIT(bit); dw_pcie_writel_dbi(pci, PCIE_MSI_INTR0_MASK + res, pp->irq_mask[ctrl]); raw_spin_unlock_irqrestore(&pp->lock, flags); } static void dw_pci_bottom_ack(struct irq_data *d) { struct dw_pcie_rp *pp = irq_data_get_irq_chip_data(d); struct dw_pcie *pci = to_dw_pcie_from_pp(pp); unsigned int res, bit, ctrl; ctrl = d->hwirq / MAX_MSI_IRQS_PER_CTRL; res = ctrl * MSI_REG_CTRL_BLOCK_SIZE; bit = d->hwirq % MAX_MSI_IRQS_PER_CTRL; dw_pcie_writel_dbi(pci, PCIE_MSI_INTR0_STATUS + res, BIT(bit)); } static struct irq_chip dw_pci_msi_bottom_irq_chip = { .name = "DWPCI-MSI", .irq_ack = dw_pci_bottom_ack, .irq_compose_msi_msg = dw_pci_setup_msi_msg, .irq_set_affinity = dw_pci_msi_set_affinity, .irq_mask = dw_pci_bottom_mask, .irq_unmask = dw_pci_bottom_unmask, }; static int dw_pcie_irq_domain_alloc(struct irq_domain *domain, unsigned int virq, unsigned int nr_irqs, void *args) { struct dw_pcie_rp *pp = domain->host_data; unsigned long flags; u32 i; int bit; raw_spin_lock_irqsave(&pp->lock, flags); bit = bitmap_find_free_region(pp->msi_irq_in_use, pp->num_vectors, order_base_2(nr_irqs)); raw_spin_unlock_irqrestore(&pp->lock, flags); if (bit < 0) return -ENOSPC; for (i = 0; i < nr_irqs; i++) irq_domain_set_info(domain, virq + i, bit + i, pp->msi_irq_chip, pp, handle_edge_irq, NULL, NULL); return 0; } static void dw_pcie_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 dw_pcie_rp *pp = domain->host_data; unsigned long flags; raw_spin_lock_irqsave(&pp->lock, flags); bitmap_release_region(pp->msi_irq_in_use, d->hwirq, order_base_2(nr_irqs)); raw_spin_unlock_irqrestore(&pp->lock, flags); } static const struct irq_domain_ops dw_pcie_msi_domain_ops = { .alloc = dw_pcie_irq_domain_alloc, .free = dw_pcie_irq_domain_free, }; int dw_pcie_allocate_domains(struct dw_pcie_rp *pp) { struct dw_pcie *pci = to_dw_pcie_from_pp(pp); struct fwnode_handle *fwnode = of_node_to_fwnode(pci->dev->of_node); pp->irq_domain = irq_domain_create_linear(fwnode, pp->num_vectors, &dw_pcie_msi_domain_ops, pp); if (!pp->irq_domain) { dev_err(pci->dev, "Failed to create IRQ domain\n"); return -ENOMEM; } irq_domain_update_bus_token(pp->irq_domain, DOMAIN_BUS_NEXUS); pp->msi_domain = pci_msi_create_irq_domain(fwnode, &dw_pcie_msi_domain_info, pp->irq_domain); if (!pp->msi_domain) { dev_err(pci->dev, "Failed to create MSI domain\n"); irq_domain_remove(pp->irq_domain); return -ENOMEM; } return 0; } static void dw_pcie_free_msi(struct dw_pcie_rp *pp) { u32 ctrl; for (ctrl = 0; ctrl < MAX_MSI_CTRLS; ctrl++) { if (pp->msi_irq[ctrl] > 0) irq_set_chained_handler_and_data(pp->msi_irq[ctrl], NULL, NULL); } irq_domain_remove(pp->msi_domain); irq_domain_remove(pp->irq_domain); } static void dw_pcie_msi_init(struct dw_pcie_rp *pp) { struct dw_pcie *pci = to_dw_pcie_from_pp(pp); u64 msi_target = (u64)pp->msi_data; if (!pci_msi_enabled() || !pp->has_msi_ctrl) return; /* Program the msi_data */ dw_pcie_writel_dbi(pci, PCIE_MSI_ADDR_LO, lower_32_bits(msi_target)); dw_pcie_writel_dbi(pci, PCIE_MSI_ADDR_HI, upper_32_bits(msi_target)); } static int dw_pcie_parse_split_msi_irq(struct dw_pcie_rp *pp) { struct dw_pcie *pci = to_dw_pcie_from_pp(pp); struct device *dev = pci->dev; struct platform_device *pdev = to_platform_device(dev); u32 ctrl, max_vectors; int irq; /* Parse any "msiX" IRQs described in the devicetree */ for (ctrl = 0; ctrl < MAX_MSI_CTRLS; ctrl++) { char msi_name[] = "msiX"; msi_name[3] = '0' + ctrl; irq = platform_get_irq_byname_optional(pdev, msi_name); if (irq == -ENXIO) break; if (irq < 0) return dev_err_probe(dev, irq, "Failed to parse MSI IRQ '%s'\n", msi_name); pp->msi_irq[ctrl] = irq; } /* If no "msiX" IRQs, caller should fallback to "msi" IRQ */ if (ctrl == 0) return -ENXIO; max_vectors = ctrl * MAX_MSI_IRQS_PER_CTRL; if (pp->num_vectors > max_vectors) { dev_warn(dev, "Exceeding number of MSI vectors, limiting to %u\n", max_vectors); pp->num_vectors = max_vectors; } if (!pp->num_vectors) pp->num_vectors = max_vectors; return 0; } static int dw_pcie_msi_host_init(struct dw_pcie_rp *pp) { struct dw_pcie *pci = to_dw_pcie_from_pp(pp); struct device *dev = pci->dev; struct platform_device *pdev = to_platform_device(dev); u64 *msi_vaddr; int ret; u32 ctrl, num_ctrls; for (ctrl = 0; ctrl < MAX_MSI_CTRLS; ctrl++) pp->irq_mask[ctrl] = ~0; if (!pp->msi_irq[0]) { ret = dw_pcie_parse_split_msi_irq(pp); if (ret < 0 && ret != -ENXIO) return ret; } if (!pp->num_vectors) pp->num_vectors = MSI_DEF_NUM_VECTORS; num_ctrls = pp->num_vectors / MAX_MSI_IRQS_PER_CTRL; if (!pp->msi_irq[0]) { pp->msi_irq[0] = platform_get_irq_byname_optional(pdev, "msi"); if (pp->msi_irq[0] < 0) { pp->msi_irq[0] = platform_get_irq(pdev, 0); if (pp->msi_irq[0] < 0) return pp->msi_irq[0]; } } dev_dbg(dev, "Using %d MSI vectors\n", pp->num_vectors); pp->msi_irq_chip = &dw_pci_msi_bottom_irq_chip; ret = dw_pcie_allocate_domains(pp); if (ret) return ret; for (ctrl = 0; ctrl < num_ctrls; ctrl++) { if (pp->msi_irq[ctrl] > 0) irq_set_chained_handler_and_data(pp->msi_irq[ctrl], dw_chained_msi_isr, pp); } /* * Even though the iMSI-RX Module supports 64-bit addresses some * peripheral PCIe devices may lack 64-bit message support. In * order not to miss MSI TLPs from those devices the MSI target * address has to be within the lowest 4GB. * * Note until there is a better alternative found the reservation is * done by allocating from the artificially limited DMA-coherent * memory. */ ret = dma_set_coherent_mask(dev, DMA_BIT_MASK(32)); if (ret) dev_warn(dev, "Failed to set DMA mask to 32-bit. Devices with only 32-bit MSI support may not work properly\n"); msi_vaddr = dmam_alloc_coherent(dev, sizeof(u64), &pp->msi_data, GFP_KERNEL); if (!msi_vaddr) { dev_err(dev, "Failed to alloc and map MSI data\n"); dw_pcie_free_msi(pp); return -ENOMEM; } return 0; } int dw_pcie_host_init(struct dw_pcie_rp *pp) { struct dw_pcie *pci = to_dw_pcie_from_pp(pp); struct device *dev = pci->dev; struct device_node *np = dev->of_node; struct platform_device *pdev = to_platform_device(dev); struct resource_entry *win; struct pci_host_bridge *bridge; struct resource *res; int ret; raw_spin_lock_init(&pp->lock); ret = dw_pcie_get_resources(pci); if (ret) return ret; res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "config"); if (res) { pp->cfg0_size = resource_size(res); pp->cfg0_base = res->start; pp->va_cfg0_base = devm_pci_remap_cfg_resource(dev, res); if (IS_ERR(pp->va_cfg0_base)) return PTR_ERR(pp->va_cfg0_base); } else { dev_err(dev, "Missing *config* reg space\n"); return -ENODEV; } bridge = devm_pci_alloc_host_bridge(dev, 0); if (!bridge) return -ENOMEM; pp->bridge = bridge; /* Get the I/O range from DT */ win = resource_list_first_type(&bridge->windows, IORESOURCE_IO); if (win) { pp->io_size = resource_size(win->res); pp->io_bus_addr = win->res->start - win->offset; pp->io_base = pci_pio_to_address(win->res->start); } /* Set default bus ops */ bridge->ops = &dw_pcie_ops; bridge->child_ops = &dw_child_pcie_ops; if (pp->ops->host_init) { ret = pp->ops->host_init(pp); if (ret) return ret; } if (pci_msi_enabled()) { pp->has_msi_ctrl = !(pp->ops->msi_host_init || of_property_read_bool(np, "msi-parent") || of_property_read_bool(np, "msi-map")); /* * For the has_msi_ctrl case the default assignment is handled * in the dw_pcie_msi_host_init(). */ if (!pp->has_msi_ctrl && !pp->num_vectors) { pp->num_vectors = MSI_DEF_NUM_VECTORS; } else if (pp->num_vectors > MAX_MSI_IRQS) { dev_err(dev, "Invalid number of vectors\n"); ret = -EINVAL; goto err_deinit_host; } if (pp->ops->msi_host_init) { ret = pp->ops->msi_host_init(pp); if (ret < 0) goto err_deinit_host; } else if (pp->has_msi_ctrl) { ret = dw_pcie_msi_host_init(pp); if (ret < 0) goto err_deinit_host; } } dw_pcie_version_detect(pci); dw_pcie_iatu_detect(pci); ret = dw_pcie_setup_rc(pp); if (ret) goto err_free_msi; if (!dw_pcie_link_up(pci)) { ret = dw_pcie_start_link(pci); if (ret) goto err_free_msi; } /* Ignore errors, the link may come up later */ dw_pcie_wait_for_link(pci); bridge->sysdata = pp; ret = pci_host_probe(bridge); if (ret) goto err_stop_link; return 0; err_stop_link: dw_pcie_stop_link(pci); err_free_msi: if (pp->has_msi_ctrl) dw_pcie_free_msi(pp); err_deinit_host: if (pp->ops->host_deinit) pp->ops->host_deinit(pp); return ret; } EXPORT_SYMBOL_GPL(dw_pcie_host_init); void dw_pcie_host_deinit(struct dw_pcie_rp *pp) { struct dw_pcie *pci = to_dw_pcie_from_pp(pp); pci_stop_root_bus(pp->bridge->bus); pci_remove_root_bus(pp->bridge->bus); dw_pcie_stop_link(pci); if (pp->has_msi_ctrl) dw_pcie_free_msi(pp); if (pp->ops->host_deinit) pp->ops->host_deinit(pp); } EXPORT_SYMBOL_GPL(dw_pcie_host_deinit); static void __iomem *dw_pcie_other_conf_map_bus(struct pci_bus *bus, unsigned int devfn, int where) { struct dw_pcie_rp *pp = bus->sysdata; struct dw_pcie *pci = to_dw_pcie_from_pp(pp); int type, ret; u32 busdev; /* * Checking whether the link is up here is a last line of defense * against platforms that forward errors on the system bus as * SError upon PCI configuration transactions issued when the link * is down. This check is racy by definition and does not stop * the system from triggering an SError if the link goes down * after this check is performed. */ if (!dw_pcie_link_up(pci)) return NULL; busdev = PCIE_ATU_BUS(bus->number) | PCIE_ATU_DEV(PCI_SLOT(devfn)) | PCIE_ATU_FUNC(PCI_FUNC(devfn)); if (pci_is_root_bus(bus->parent)) type = PCIE_ATU_TYPE_CFG0; else type = PCIE_ATU_TYPE_CFG1; ret = dw_pcie_prog_outbound_atu(pci, 0, type, pp->cfg0_base, busdev, pp->cfg0_size); if (ret) return NULL; return pp->va_cfg0_base + where; } static int dw_pcie_rd_other_conf(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 *val) { struct dw_pcie_rp *pp = bus->sysdata; struct dw_pcie *pci = to_dw_pcie_from_pp(pp); int ret; ret = pci_generic_config_read(bus, devfn, where, size, val); if (ret != PCIBIOS_SUCCESSFUL) return ret; if (pp->cfg0_io_shared) { ret = dw_pcie_prog_outbound_atu(pci, 0, PCIE_ATU_TYPE_IO, pp->io_base, pp->io_bus_addr, pp->io_size); if (ret) return PCIBIOS_SET_FAILED; } return PCIBIOS_SUCCESSFUL; } static int dw_pcie_wr_other_conf(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 val) { struct dw_pcie_rp *pp = bus->sysdata; struct dw_pcie *pci = to_dw_pcie_from_pp(pp); int ret; ret = pci_generic_config_write(bus, devfn, where, size, val); if (ret != PCIBIOS_SUCCESSFUL) return ret; if (pp->cfg0_io_shared) { ret = dw_pcie_prog_outbound_atu(pci, 0, PCIE_ATU_TYPE_IO, pp->io_base, pp->io_bus_addr, pp->io_size); if (ret) return PCIBIOS_SET_FAILED; } return PCIBIOS_SUCCESSFUL; } static struct pci_ops dw_child_pcie_ops = { .map_bus = dw_pcie_other_conf_map_bus, .read = dw_pcie_rd_other_conf, .write = dw_pcie_wr_other_conf, }; void __iomem *dw_pcie_own_conf_map_bus(struct pci_bus *bus, unsigned int devfn, int where) { struct dw_pcie_rp *pp = bus->sysdata; struct dw_pcie *pci = to_dw_pcie_from_pp(pp); if (PCI_SLOT(devfn) > 0) return NULL; return pci->dbi_base + where; } EXPORT_SYMBOL_GPL(dw_pcie_own_conf_map_bus); static struct pci_ops dw_pcie_ops = { .map_bus = dw_pcie_own_conf_map_bus, .read = pci_generic_config_read, .write = pci_generic_config_write, }; static int dw_pcie_iatu_setup(struct dw_pcie_rp *pp) { struct dw_pcie *pci = to_dw_pcie_from_pp(pp); struct resource_entry *entry; int i, ret; /* Note the very first outbound ATU is used for CFG IOs */ if (!pci->num_ob_windows) { dev_err(pci->dev, "No outbound iATU found\n"); return -EINVAL; } /* * Ensure all out/inbound windows are disabled before proceeding with * the MEM/IO (dma-)ranges setups. */ for (i = 0; i < pci->num_ob_windows; i++) dw_pcie_disable_atu(pci, PCIE_ATU_REGION_DIR_OB, i); for (i = 0; i < pci->num_ib_windows; i++) dw_pcie_disable_atu(pci, PCIE_ATU_REGION_DIR_IB, i); i = 0; resource_list_for_each_entry(entry, &pp->bridge->windows) { if (resource_type(entry->res) != IORESOURCE_MEM) continue; if (pci->num_ob_windows <= ++i) break; ret = dw_pcie_prog_outbound_atu(pci, i, PCIE_ATU_TYPE_MEM, entry->res->start, entry->res->start - entry->offset, resource_size(entry->res)); if (ret) { dev_err(pci->dev, "Failed to set MEM range %pr\n", entry->res); return ret; } } if (pp->io_size) { if (pci->num_ob_windows > ++i) { ret = dw_pcie_prog_outbound_atu(pci, i, PCIE_ATU_TYPE_IO, pp->io_base, pp->io_bus_addr, pp->io_size); if (ret) { dev_err(pci->dev, "Failed to set IO range %pr\n", entry->res); return ret; } } else { pp->cfg0_io_shared = true; } } if (pci->num_ob_windows <= i) dev_warn(pci->dev, "Ranges exceed outbound iATU size (%d)\n", pci->num_ob_windows); i = 0; resource_list_for_each_entry(entry, &pp->bridge->dma_ranges) { if (resource_type(entry->res) != IORESOURCE_MEM) continue; if (pci->num_ib_windows <= i) break; ret = dw_pcie_prog_inbound_atu(pci, i++, PCIE_ATU_TYPE_MEM, entry->res->start, entry->res->start - entry->offset, resource_size(entry->res)); if (ret) { dev_err(pci->dev, "Failed to set DMA range %pr\n", entry->res); return ret; } } if (pci->num_ib_windows <= i) dev_warn(pci->dev, "Dma-ranges exceed inbound iATU size (%u)\n", pci->num_ib_windows); return 0; } int dw_pcie_setup_rc(struct dw_pcie_rp *pp) { struct dw_pcie *pci = to_dw_pcie_from_pp(pp); u32 val, ctrl, num_ctrls; int ret; /* * Enable DBI read-only registers for writing/updating configuration. * Write permission gets disabled towards the end of this function. */ dw_pcie_dbi_ro_wr_en(pci); dw_pcie_setup(pci); if (pp->has_msi_ctrl) { num_ctrls = pp->num_vectors / MAX_MSI_IRQS_PER_CTRL; /* Initialize IRQ Status array */ for (ctrl = 0; ctrl < num_ctrls; ctrl++) { dw_pcie_writel_dbi(pci, PCIE_MSI_INTR0_MASK + (ctrl * MSI_REG_CTRL_BLOCK_SIZE), pp->irq_mask[ctrl]); dw_pcie_writel_dbi(pci, PCIE_MSI_INTR0_ENABLE + (ctrl * MSI_REG_CTRL_BLOCK_SIZE), ~0); } } dw_pcie_msi_init(pp); /* Setup RC BARs */ dw_pcie_writel_dbi(pci, PCI_BASE_ADDRESS_0, 0x00000004); dw_pcie_writel_dbi(pci, PCI_BASE_ADDRESS_1, 0x00000000); /* Setup interrupt pins */ val = dw_pcie_readl_dbi(pci, PCI_INTERRUPT_LINE); val &= 0xffff00ff; val |= 0x00000100; dw_pcie_writel_dbi(pci, PCI_INTERRUPT_LINE, val); /* Setup bus numbers */ val = dw_pcie_readl_dbi(pci, PCI_PRIMARY_BUS); val &= 0xff000000; val |= 0x00ff0100; dw_pcie_writel_dbi(pci, PCI_PRIMARY_BUS, val); /* Setup command register */ val = dw_pcie_readl_dbi(pci, PCI_COMMAND); val &= 0xffff0000; val |= PCI_COMMAND_IO | PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER | PCI_COMMAND_SERR; dw_pcie_writel_dbi(pci, PCI_COMMAND, val); /* * If the platform provides its own child bus config accesses, it means * the platform uses its own address translation component rather than * ATU, so we should not program the ATU here. */ if (pp->bridge->child_ops == &dw_child_pcie_ops) { ret = dw_pcie_iatu_setup(pp); if (ret) return ret; } dw_pcie_writel_dbi(pci, PCI_BASE_ADDRESS_0, 0); /* Program correct class for RC */ dw_pcie_writew_dbi(pci, PCI_CLASS_DEVICE, PCI_CLASS_BRIDGE_PCI); val = dw_pcie_readl_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL); val |= PORT_LOGIC_SPEED_CHANGE; dw_pcie_writel_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL, val); dw_pcie_dbi_ro_wr_dis(pci); return 0; } EXPORT_SYMBOL_GPL(dw_pcie_setup_rc);