![Shawn Lin](/assets/img/avatar_default.png)
Native PCI drivers for root complex devices were originally all in drivers/pci/host/. Some of these devices can also be operated in endpoint mode. Drivers for endpoint mode didn't seem to fit in the "host" directory, so we put both the root complex and endpoint drivers in per-device directories, e.g., drivers/pci/dwc/, drivers/pci/cadence/, etc. These per-device directories contain trivial Kconfig and Makefiles and clutter drivers/pci/. Make a new drivers/pci/controllers/ directory and collect all the device-specific drivers there. No functional change intended. Link: https://lkml.kernel.org/r/1520304202-232891-1-git-send-email-shawn.lin@rock-chips.com Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com> [bhelgaas: changelog] Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
292 lines
7 KiB
C
292 lines
7 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Altera PCIe MSI support
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*
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* Author: Ley Foon Tan <lftan@altera.com>
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*
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* Copyright Altera Corporation (C) 2013-2015. All rights reserved
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*/
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#include <linux/interrupt.h>
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#include <linux/irqchip/chained_irq.h>
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#include <linux/init.h>
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#include <linux/msi.h>
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#include <linux/of_address.h>
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#include <linux/of_irq.h>
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#include <linux/of_pci.h>
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#include <linux/pci.h>
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#include <linux/platform_device.h>
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#include <linux/slab.h>
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#define MSI_STATUS 0x0
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#define MSI_ERROR 0x4
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#define MSI_INTMASK 0x8
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#define MAX_MSI_VECTORS 32
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struct altera_msi {
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DECLARE_BITMAP(used, MAX_MSI_VECTORS);
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struct mutex lock; /* protect "used" bitmap */
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struct platform_device *pdev;
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struct irq_domain *msi_domain;
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struct irq_domain *inner_domain;
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void __iomem *csr_base;
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void __iomem *vector_base;
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phys_addr_t vector_phy;
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u32 num_of_vectors;
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int irq;
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};
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static inline void msi_writel(struct altera_msi *msi, const u32 value,
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const u32 reg)
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{
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writel_relaxed(value, msi->csr_base + reg);
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}
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static inline u32 msi_readl(struct altera_msi *msi, const u32 reg)
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{
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return readl_relaxed(msi->csr_base + reg);
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}
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static void altera_msi_isr(struct irq_desc *desc)
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{
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struct irq_chip *chip = irq_desc_get_chip(desc);
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struct altera_msi *msi;
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unsigned long status;
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u32 bit;
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u32 virq;
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chained_irq_enter(chip, desc);
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msi = irq_desc_get_handler_data(desc);
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while ((status = msi_readl(msi, MSI_STATUS)) != 0) {
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for_each_set_bit(bit, &status, msi->num_of_vectors) {
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/* Dummy read from vector to clear the interrupt */
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readl_relaxed(msi->vector_base + (bit * sizeof(u32)));
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virq = irq_find_mapping(msi->inner_domain, bit);
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if (virq)
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generic_handle_irq(virq);
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else
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dev_err(&msi->pdev->dev, "unexpected MSI\n");
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}
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}
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chained_irq_exit(chip, desc);
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}
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static struct irq_chip altera_msi_irq_chip = {
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.name = "Altera PCIe MSI",
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.irq_mask = pci_msi_mask_irq,
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.irq_unmask = pci_msi_unmask_irq,
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};
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static struct msi_domain_info altera_msi_domain_info = {
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.flags = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
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MSI_FLAG_PCI_MSIX),
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.chip = &altera_msi_irq_chip,
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};
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static void altera_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
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{
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struct altera_msi *msi = irq_data_get_irq_chip_data(data);
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phys_addr_t addr = msi->vector_phy + (data->hwirq * sizeof(u32));
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msg->address_lo = lower_32_bits(addr);
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msg->address_hi = upper_32_bits(addr);
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msg->data = data->hwirq;
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dev_dbg(&msi->pdev->dev, "msi#%d address_hi %#x address_lo %#x\n",
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(int)data->hwirq, msg->address_hi, msg->address_lo);
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}
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static int altera_msi_set_affinity(struct irq_data *irq_data,
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const struct cpumask *mask, bool force)
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{
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return -EINVAL;
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}
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static struct irq_chip altera_msi_bottom_irq_chip = {
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.name = "Altera MSI",
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.irq_compose_msi_msg = altera_compose_msi_msg,
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.irq_set_affinity = altera_msi_set_affinity,
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};
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static int altera_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
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unsigned int nr_irqs, void *args)
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{
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struct altera_msi *msi = domain->host_data;
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unsigned long bit;
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u32 mask;
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WARN_ON(nr_irqs != 1);
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mutex_lock(&msi->lock);
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bit = find_first_zero_bit(msi->used, msi->num_of_vectors);
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if (bit >= msi->num_of_vectors) {
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mutex_unlock(&msi->lock);
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return -ENOSPC;
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}
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set_bit(bit, msi->used);
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mutex_unlock(&msi->lock);
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irq_domain_set_info(domain, virq, bit, &altera_msi_bottom_irq_chip,
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domain->host_data, handle_simple_irq,
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NULL, NULL);
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mask = msi_readl(msi, MSI_INTMASK);
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mask |= 1 << bit;
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msi_writel(msi, mask, MSI_INTMASK);
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return 0;
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}
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static void altera_irq_domain_free(struct irq_domain *domain,
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unsigned int virq, unsigned int nr_irqs)
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{
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struct irq_data *d = irq_domain_get_irq_data(domain, virq);
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struct altera_msi *msi = irq_data_get_irq_chip_data(d);
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u32 mask;
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mutex_lock(&msi->lock);
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if (!test_bit(d->hwirq, msi->used)) {
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dev_err(&msi->pdev->dev, "trying to free unused MSI#%lu\n",
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d->hwirq);
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} else {
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__clear_bit(d->hwirq, msi->used);
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mask = msi_readl(msi, MSI_INTMASK);
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mask &= ~(1 << d->hwirq);
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msi_writel(msi, mask, MSI_INTMASK);
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}
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mutex_unlock(&msi->lock);
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}
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static const struct irq_domain_ops msi_domain_ops = {
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.alloc = altera_irq_domain_alloc,
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.free = altera_irq_domain_free,
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};
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static int altera_allocate_domains(struct altera_msi *msi)
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{
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struct fwnode_handle *fwnode = of_node_to_fwnode(msi->pdev->dev.of_node);
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msi->inner_domain = irq_domain_add_linear(NULL, msi->num_of_vectors,
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&msi_domain_ops, msi);
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if (!msi->inner_domain) {
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dev_err(&msi->pdev->dev, "failed to create IRQ domain\n");
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return -ENOMEM;
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}
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msi->msi_domain = pci_msi_create_irq_domain(fwnode,
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&altera_msi_domain_info, msi->inner_domain);
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if (!msi->msi_domain) {
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dev_err(&msi->pdev->dev, "failed to create MSI domain\n");
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irq_domain_remove(msi->inner_domain);
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return -ENOMEM;
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}
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return 0;
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}
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static void altera_free_domains(struct altera_msi *msi)
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{
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irq_domain_remove(msi->msi_domain);
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irq_domain_remove(msi->inner_domain);
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}
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static int altera_msi_remove(struct platform_device *pdev)
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{
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struct altera_msi *msi = platform_get_drvdata(pdev);
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msi_writel(msi, 0, MSI_INTMASK);
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irq_set_chained_handler(msi->irq, NULL);
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irq_set_handler_data(msi->irq, NULL);
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altera_free_domains(msi);
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platform_set_drvdata(pdev, NULL);
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return 0;
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}
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static int altera_msi_probe(struct platform_device *pdev)
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{
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struct altera_msi *msi;
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struct device_node *np = pdev->dev.of_node;
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struct resource *res;
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int ret;
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msi = devm_kzalloc(&pdev->dev, sizeof(struct altera_msi),
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GFP_KERNEL);
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if (!msi)
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return -ENOMEM;
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mutex_init(&msi->lock);
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msi->pdev = pdev;
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res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "csr");
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msi->csr_base = devm_ioremap_resource(&pdev->dev, res);
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if (IS_ERR(msi->csr_base)) {
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dev_err(&pdev->dev, "failed to map csr memory\n");
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return PTR_ERR(msi->csr_base);
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}
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res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
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"vector_slave");
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msi->vector_base = devm_ioremap_resource(&pdev->dev, res);
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if (IS_ERR(msi->vector_base)) {
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dev_err(&pdev->dev, "failed to map vector_slave memory\n");
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return PTR_ERR(msi->vector_base);
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}
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msi->vector_phy = res->start;
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if (of_property_read_u32(np, "num-vectors", &msi->num_of_vectors)) {
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dev_err(&pdev->dev, "failed to parse the number of vectors\n");
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return -EINVAL;
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}
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ret = altera_allocate_domains(msi);
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if (ret)
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return ret;
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msi->irq = platform_get_irq(pdev, 0);
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if (msi->irq < 0) {
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dev_err(&pdev->dev, "failed to map IRQ: %d\n", msi->irq);
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ret = msi->irq;
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goto err;
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}
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irq_set_chained_handler_and_data(msi->irq, altera_msi_isr, msi);
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platform_set_drvdata(pdev, msi);
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return 0;
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err:
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altera_msi_remove(pdev);
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return ret;
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}
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static const struct of_device_id altera_msi_of_match[] = {
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{ .compatible = "altr,msi-1.0", NULL },
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{ },
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};
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static struct platform_driver altera_msi_driver = {
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.driver = {
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.name = "altera-msi",
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.of_match_table = altera_msi_of_match,
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},
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.probe = altera_msi_probe,
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.remove = altera_msi_remove,
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};
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static int __init altera_msi_init(void)
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{
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return platform_driver_register(&altera_msi_driver);
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}
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subsys_initcall(altera_msi_init);
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