1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * MSI support for PPC4xx SoCs using High Speed Transfer Assist (HSTA) for
4 * generation of the interrupt.
6 * Copyright © 2013 Alistair Popple <alistair@popple.id.au> IBM Corporation
9 #include <linux/kernel.h>
10 #include <linux/interrupt.h>
11 #include <linux/msi.h>
13 #include <linux/of_irq.h>
14 #include <linux/platform_device.h>
15 #include <linux/pci.h>
16 #include <linux/semaphore.h>
17 #include <asm/msi_bitmap.h>
18 #include <asm/ppc-pci.h>
20 struct ppc4xx_hsta_msi {
23 /* The ioremapped HSTA MSI IO space */
26 /* Physical address of HSTA MSI IO space */
28 struct msi_bitmap bmp;
30 /* An array mapping offsets to hardware IRQs */
33 /* Number of hwirqs supported */
36 static struct ppc4xx_hsta_msi ppc4xx_hsta_msi;
38 static int hsta_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
41 struct msi_desc *entry;
45 /* We don't support MSI-X */
46 if (type == PCI_CAP_ID_MSIX) {
47 pr_debug("%s: MSI-X not supported.\n", __func__);
51 msi_for_each_desc(entry, &dev->dev, MSI_DESC_NOTASSOCIATED) {
52 irq = msi_bitmap_alloc_hwirqs(&ppc4xx_hsta_msi.bmp, 1);
54 pr_debug("%s: Failed to allocate msi interrupt\n",
59 hwirq = ppc4xx_hsta_msi.irq_map[irq];
61 pr_err("%s: Failed mapping irq %d\n", __func__, irq);
66 * HSTA generates interrupts on writes to 128-bit aligned
69 addr = ppc4xx_hsta_msi.address + irq*0x10;
70 msg.address_hi = upper_32_bits(addr);
71 msg.address_lo = lower_32_bits(addr);
73 /* Data is not used by the HSTA. */
76 pr_debug("%s: Setup irq %d (0x%0llx)\n", __func__, hwirq,
77 (((u64) msg.address_hi) << 32) | msg.address_lo);
79 if (irq_set_msi_desc(hwirq, entry)) {
81 "%s: Invalid hwirq %d specified in device tree\n",
83 msi_bitmap_free_hwirqs(&ppc4xx_hsta_msi.bmp, irq, 1);
86 pci_write_msi_msg(hwirq, &msg);
92 static int hsta_find_hwirq_offset(int hwirq)
96 /* Find the offset given the hwirq */
97 for (irq = 0; irq < ppc4xx_hsta_msi.irq_count; irq++)
98 if (ppc4xx_hsta_msi.irq_map[irq] == hwirq)
104 static void hsta_teardown_msi_irqs(struct pci_dev *dev)
106 struct msi_desc *entry;
109 msi_for_each_desc(entry, &dev->dev, MSI_DESC_ASSOCIATED) {
110 irq = hsta_find_hwirq_offset(entry->irq);
112 /* entry->irq should always be in irq_map */
114 irq_set_msi_desc(entry->irq, NULL);
115 msi_bitmap_free_hwirqs(&ppc4xx_hsta_msi.bmp, irq, 1);
116 pr_debug("%s: Teardown IRQ %u (index %u)\n", __func__,
122 static int hsta_msi_probe(struct platform_device *pdev)
124 struct device *dev = &pdev->dev;
125 struct resource *mem;
126 int irq, ret, irq_count;
127 struct pci_controller *phb;
129 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
131 dev_err(dev, "Unable to get mmio space\n");
135 irq_count = of_irq_count(dev->of_node);
137 dev_err(dev, "Unable to find IRQ range\n");
141 ppc4xx_hsta_msi.dev = dev;
142 ppc4xx_hsta_msi.address = mem->start;
143 ppc4xx_hsta_msi.data = ioremap(mem->start, resource_size(mem));
144 ppc4xx_hsta_msi.irq_count = irq_count;
145 if (!ppc4xx_hsta_msi.data) {
146 dev_err(dev, "Unable to map memory\n");
150 ret = msi_bitmap_alloc(&ppc4xx_hsta_msi.bmp, irq_count, dev->of_node);
154 ppc4xx_hsta_msi.irq_map = kmalloc_array(irq_count, sizeof(int),
156 if (!ppc4xx_hsta_msi.irq_map) {
161 /* Setup a mapping from irq offsets to hardware irq numbers */
162 for (irq = 0; irq < irq_count; irq++) {
163 ppc4xx_hsta_msi.irq_map[irq] =
164 irq_of_parse_and_map(dev->of_node, irq);
165 if (!ppc4xx_hsta_msi.irq_map[irq]) {
166 dev_err(dev, "Unable to map IRQ\n");
172 list_for_each_entry(phb, &hose_list, list_node) {
173 phb->controller_ops.setup_msi_irqs = hsta_setup_msi_irqs;
174 phb->controller_ops.teardown_msi_irqs = hsta_teardown_msi_irqs;
179 kfree(ppc4xx_hsta_msi.irq_map);
182 msi_bitmap_free(&ppc4xx_hsta_msi.bmp);
185 iounmap(ppc4xx_hsta_msi.data);
189 static const struct of_device_id hsta_msi_ids[] = {
191 .compatible = "ibm,hsta-msi",
196 static struct platform_driver hsta_msi_driver = {
197 .probe = hsta_msi_probe,
200 .of_match_table = hsta_msi_ids,
204 static int hsta_msi_init(void)
206 return platform_driver_register(&hsta_msi_driver);
208 subsys_initcall(hsta_msi_init);