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209 lines
4.6 KiB
209 lines
4.6 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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* MSI support for PPC4xx SoCs using High Speed Transfer Assist (HSTA) for |
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* generation of the interrupt. |
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* |
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* Copyright © 2013 Alistair Popple <[email protected]> IBM Corporation |
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*/ |
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#include <linux/kernel.h> |
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#include <linux/interrupt.h> |
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#include <linux/msi.h> |
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#include <linux/of.h> |
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#include <linux/of_platform.h> |
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#include <linux/pci.h> |
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#include <linux/semaphore.h> |
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#include <asm/msi_bitmap.h> |
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#include <asm/ppc-pci.h> |
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struct ppc4xx_hsta_msi { |
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struct device *dev; |
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/* The ioremapped HSTA MSI IO space */ |
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u32 __iomem *data; |
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/* Physical address of HSTA MSI IO space */ |
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u64 address; |
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struct msi_bitmap bmp; |
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/* An array mapping offsets to hardware IRQs */ |
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int *irq_map; |
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/* Number of hwirqs supported */ |
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int irq_count; |
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}; |
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static struct ppc4xx_hsta_msi ppc4xx_hsta_msi; |
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static int hsta_setup_msi_irqs(struct pci_dev *dev, int nvec, int type) |
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{ |
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struct msi_msg msg; |
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struct msi_desc *entry; |
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int irq, hwirq; |
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u64 addr; |
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/* We don't support MSI-X */ |
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if (type == PCI_CAP_ID_MSIX) { |
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pr_debug("%s: MSI-X not supported.\n", __func__); |
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return -EINVAL; |
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} |
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for_each_pci_msi_entry(entry, dev) { |
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irq = msi_bitmap_alloc_hwirqs(&ppc4xx_hsta_msi.bmp, 1); |
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if (irq < 0) { |
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pr_debug("%s: Failed to allocate msi interrupt\n", |
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__func__); |
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return irq; |
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} |
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hwirq = ppc4xx_hsta_msi.irq_map[irq]; |
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if (!hwirq) { |
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pr_err("%s: Failed mapping irq %d\n", __func__, irq); |
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return -EINVAL; |
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} |
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/* |
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* HSTA generates interrupts on writes to 128-bit aligned |
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* addresses. |
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*/ |
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addr = ppc4xx_hsta_msi.address + irq*0x10; |
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msg.address_hi = upper_32_bits(addr); |
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msg.address_lo = lower_32_bits(addr); |
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/* Data is not used by the HSTA. */ |
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msg.data = 0; |
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pr_debug("%s: Setup irq %d (0x%0llx)\n", __func__, hwirq, |
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(((u64) msg.address_hi) << 32) | msg.address_lo); |
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if (irq_set_msi_desc(hwirq, entry)) { |
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pr_err( |
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"%s: Invalid hwirq %d specified in device tree\n", |
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__func__, hwirq); |
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msi_bitmap_free_hwirqs(&ppc4xx_hsta_msi.bmp, irq, 1); |
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return -EINVAL; |
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} |
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pci_write_msi_msg(hwirq, &msg); |
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} |
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return 0; |
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} |
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static int hsta_find_hwirq_offset(int hwirq) |
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{ |
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int irq; |
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/* Find the offset given the hwirq */ |
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for (irq = 0; irq < ppc4xx_hsta_msi.irq_count; irq++) |
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if (ppc4xx_hsta_msi.irq_map[irq] == hwirq) |
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return irq; |
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return -EINVAL; |
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} |
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static void hsta_teardown_msi_irqs(struct pci_dev *dev) |
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{ |
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struct msi_desc *entry; |
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int irq; |
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for_each_pci_msi_entry(entry, dev) { |
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if (!entry->irq) |
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continue; |
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irq = hsta_find_hwirq_offset(entry->irq); |
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/* entry->irq should always be in irq_map */ |
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BUG_ON(irq < 0); |
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irq_set_msi_desc(entry->irq, NULL); |
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msi_bitmap_free_hwirqs(&ppc4xx_hsta_msi.bmp, irq, 1); |
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pr_debug("%s: Teardown IRQ %u (index %u)\n", __func__, |
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entry->irq, irq); |
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} |
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} |
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static int hsta_msi_probe(struct platform_device *pdev) |
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{ |
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struct device *dev = &pdev->dev; |
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struct resource *mem; |
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int irq, ret, irq_count; |
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struct pci_controller *phb; |
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mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
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if (!mem) { |
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dev_err(dev, "Unable to get mmio space\n"); |
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return -EINVAL; |
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} |
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irq_count = of_irq_count(dev->of_node); |
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if (!irq_count) { |
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dev_err(dev, "Unable to find IRQ range\n"); |
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return -EINVAL; |
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} |
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ppc4xx_hsta_msi.dev = dev; |
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ppc4xx_hsta_msi.address = mem->start; |
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ppc4xx_hsta_msi.data = ioremap(mem->start, resource_size(mem)); |
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ppc4xx_hsta_msi.irq_count = irq_count; |
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if (!ppc4xx_hsta_msi.data) { |
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dev_err(dev, "Unable to map memory\n"); |
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return -ENOMEM; |
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} |
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ret = msi_bitmap_alloc(&ppc4xx_hsta_msi.bmp, irq_count, dev->of_node); |
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if (ret) |
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goto out; |
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ppc4xx_hsta_msi.irq_map = kmalloc_array(irq_count, sizeof(int), |
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GFP_KERNEL); |
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if (!ppc4xx_hsta_msi.irq_map) { |
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ret = -ENOMEM; |
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goto out1; |
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} |
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/* Setup a mapping from irq offsets to hardware irq numbers */ |
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for (irq = 0; irq < irq_count; irq++) { |
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ppc4xx_hsta_msi.irq_map[irq] = |
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irq_of_parse_and_map(dev->of_node, irq); |
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if (!ppc4xx_hsta_msi.irq_map[irq]) { |
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dev_err(dev, "Unable to map IRQ\n"); |
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ret = -EINVAL; |
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goto out2; |
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} |
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} |
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list_for_each_entry(phb, &hose_list, list_node) { |
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phb->controller_ops.setup_msi_irqs = hsta_setup_msi_irqs; |
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phb->controller_ops.teardown_msi_irqs = hsta_teardown_msi_irqs; |
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} |
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return 0; |
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out2: |
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kfree(ppc4xx_hsta_msi.irq_map); |
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out1: |
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msi_bitmap_free(&ppc4xx_hsta_msi.bmp); |
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out: |
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iounmap(ppc4xx_hsta_msi.data); |
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return ret; |
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} |
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static const struct of_device_id hsta_msi_ids[] = { |
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{ |
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.compatible = "ibm,hsta-msi", |
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}, |
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{} |
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}; |
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static struct platform_driver hsta_msi_driver = { |
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.probe = hsta_msi_probe, |
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.driver = { |
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.name = "hsta-msi", |
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.of_match_table = hsta_msi_ids, |
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}, |
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}; |
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static int hsta_msi_init(void) |
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{ |
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return platform_driver_register(&hsta_msi_driver); |
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} |
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subsys_initcall(hsta_msi_init);
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