12874c5fdSThomas Gleixner // SPDX-License-Identifier: GPL-2.0-or-later
2bfa9a2ebSMichael Ellerman /*
3bfa9a2ebSMichael Ellerman * MSI support for PPC4xx SoCs using High Speed Transfer Assist (HSTA) for
4bfa9a2ebSMichael Ellerman * generation of the interrupt.
5bfa9a2ebSMichael Ellerman *
6bfa9a2ebSMichael Ellerman * Copyright © 2013 Alistair Popple <alistair@popple.id.au> IBM Corporation
7bfa9a2ebSMichael Ellerman */
8bfa9a2ebSMichael Ellerman
9bfa9a2ebSMichael Ellerman #include <linux/kernel.h>
10bfa9a2ebSMichael Ellerman #include <linux/interrupt.h>
11bfa9a2ebSMichael Ellerman #include <linux/msi.h>
12bfa9a2ebSMichael Ellerman #include <linux/of.h>
13e6f6390aSChristophe Leroy #include <linux/of_irq.h>
14*81d7cac4SRob Herring #include <linux/platform_device.h>
15bfa9a2ebSMichael Ellerman #include <linux/pci.h>
16bfa9a2ebSMichael Ellerman #include <linux/semaphore.h>
17bfa9a2ebSMichael Ellerman #include <asm/msi_bitmap.h>
18bfa9a2ebSMichael Ellerman #include <asm/ppc-pci.h>
19bfa9a2ebSMichael Ellerman
20bfa9a2ebSMichael Ellerman struct ppc4xx_hsta_msi {
21bfa9a2ebSMichael Ellerman struct device *dev;
22bfa9a2ebSMichael Ellerman
23bfa9a2ebSMichael Ellerman /* The ioremapped HSTA MSI IO space */
24bfa9a2ebSMichael Ellerman u32 __iomem *data;
25bfa9a2ebSMichael Ellerman
26bfa9a2ebSMichael Ellerman /* Physical address of HSTA MSI IO space */
27bfa9a2ebSMichael Ellerman u64 address;
28bfa9a2ebSMichael Ellerman struct msi_bitmap bmp;
29bfa9a2ebSMichael Ellerman
30bfa9a2ebSMichael Ellerman /* An array mapping offsets to hardware IRQs */
31bfa9a2ebSMichael Ellerman int *irq_map;
32bfa9a2ebSMichael Ellerman
33bfa9a2ebSMichael Ellerman /* Number of hwirqs supported */
34bfa9a2ebSMichael Ellerman int irq_count;
35bfa9a2ebSMichael Ellerman };
36bfa9a2ebSMichael Ellerman static struct ppc4xx_hsta_msi ppc4xx_hsta_msi;
37bfa9a2ebSMichael Ellerman
hsta_setup_msi_irqs(struct pci_dev * dev,int nvec,int type)38bfa9a2ebSMichael Ellerman static int hsta_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
39bfa9a2ebSMichael Ellerman {
40bfa9a2ebSMichael Ellerman struct msi_msg msg;
41bfa9a2ebSMichael Ellerman struct msi_desc *entry;
42bfa9a2ebSMichael Ellerman int irq, hwirq;
43bfa9a2ebSMichael Ellerman u64 addr;
44bfa9a2ebSMichael Ellerman
45bfa9a2ebSMichael Ellerman /* We don't support MSI-X */
46bfa9a2ebSMichael Ellerman if (type == PCI_CAP_ID_MSIX) {
47bfa9a2ebSMichael Ellerman pr_debug("%s: MSI-X not supported.\n", __func__);
48bfa9a2ebSMichael Ellerman return -EINVAL;
49bfa9a2ebSMichael Ellerman }
50bfa9a2ebSMichael Ellerman
5185dabc2fSThomas Gleixner msi_for_each_desc(entry, &dev->dev, MSI_DESC_NOTASSOCIATED) {
52bfa9a2ebSMichael Ellerman irq = msi_bitmap_alloc_hwirqs(&ppc4xx_hsta_msi.bmp, 1);
53bfa9a2ebSMichael Ellerman if (irq < 0) {
54bfa9a2ebSMichael Ellerman pr_debug("%s: Failed to allocate msi interrupt\n",
55bfa9a2ebSMichael Ellerman __func__);
56bfa9a2ebSMichael Ellerman return irq;
57bfa9a2ebSMichael Ellerman }
58bfa9a2ebSMichael Ellerman
59bfa9a2ebSMichael Ellerman hwirq = ppc4xx_hsta_msi.irq_map[irq];
60bfa9a2ebSMichael Ellerman if (!hwirq) {
61bfa9a2ebSMichael Ellerman pr_err("%s: Failed mapping irq %d\n", __func__, irq);
62bfa9a2ebSMichael Ellerman return -EINVAL;
63bfa9a2ebSMichael Ellerman }
64bfa9a2ebSMichael Ellerman
65bfa9a2ebSMichael Ellerman /*
66bfa9a2ebSMichael Ellerman * HSTA generates interrupts on writes to 128-bit aligned
67bfa9a2ebSMichael Ellerman * addresses.
68bfa9a2ebSMichael Ellerman */
69bfa9a2ebSMichael Ellerman addr = ppc4xx_hsta_msi.address + irq*0x10;
70bfa9a2ebSMichael Ellerman msg.address_hi = upper_32_bits(addr);
71bfa9a2ebSMichael Ellerman msg.address_lo = lower_32_bits(addr);
72bfa9a2ebSMichael Ellerman
73bfa9a2ebSMichael Ellerman /* Data is not used by the HSTA. */
74bfa9a2ebSMichael Ellerman msg.data = 0;
75bfa9a2ebSMichael Ellerman
76bfa9a2ebSMichael Ellerman pr_debug("%s: Setup irq %d (0x%0llx)\n", __func__, hwirq,
77bfa9a2ebSMichael Ellerman (((u64) msg.address_hi) << 32) | msg.address_lo);
78bfa9a2ebSMichael Ellerman
79bfa9a2ebSMichael Ellerman if (irq_set_msi_desc(hwirq, entry)) {
80bfa9a2ebSMichael Ellerman pr_err(
81bfa9a2ebSMichael Ellerman "%s: Invalid hwirq %d specified in device tree\n",
82bfa9a2ebSMichael Ellerman __func__, hwirq);
83bfa9a2ebSMichael Ellerman msi_bitmap_free_hwirqs(&ppc4xx_hsta_msi.bmp, irq, 1);
84bfa9a2ebSMichael Ellerman return -EINVAL;
85bfa9a2ebSMichael Ellerman }
86bfa9a2ebSMichael Ellerman pci_write_msi_msg(hwirq, &msg);
87bfa9a2ebSMichael Ellerman }
88bfa9a2ebSMichael Ellerman
89bfa9a2ebSMichael Ellerman return 0;
90bfa9a2ebSMichael Ellerman }
91bfa9a2ebSMichael Ellerman
hsta_find_hwirq_offset(int hwirq)92bfa9a2ebSMichael Ellerman static int hsta_find_hwirq_offset(int hwirq)
93bfa9a2ebSMichael Ellerman {
94bfa9a2ebSMichael Ellerman int irq;
95bfa9a2ebSMichael Ellerman
96bfa9a2ebSMichael Ellerman /* Find the offset given the hwirq */
97bfa9a2ebSMichael Ellerman for (irq = 0; irq < ppc4xx_hsta_msi.irq_count; irq++)
98bfa9a2ebSMichael Ellerman if (ppc4xx_hsta_msi.irq_map[irq] == hwirq)
99bfa9a2ebSMichael Ellerman return irq;
100bfa9a2ebSMichael Ellerman
101bfa9a2ebSMichael Ellerman return -EINVAL;
102bfa9a2ebSMichael Ellerman }
103bfa9a2ebSMichael Ellerman
hsta_teardown_msi_irqs(struct pci_dev * dev)104bfa9a2ebSMichael Ellerman static void hsta_teardown_msi_irqs(struct pci_dev *dev)
105bfa9a2ebSMichael Ellerman {
106bfa9a2ebSMichael Ellerman struct msi_desc *entry;
107bfa9a2ebSMichael Ellerman int irq;
108bfa9a2ebSMichael Ellerman
10985dabc2fSThomas Gleixner msi_for_each_desc(entry, &dev->dev, MSI_DESC_ASSOCIATED) {
110bfa9a2ebSMichael Ellerman irq = hsta_find_hwirq_offset(entry->irq);
111bfa9a2ebSMichael Ellerman
112bfa9a2ebSMichael Ellerman /* entry->irq should always be in irq_map */
113bfa9a2ebSMichael Ellerman BUG_ON(irq < 0);
114bfa9a2ebSMichael Ellerman irq_set_msi_desc(entry->irq, NULL);
115bfa9a2ebSMichael Ellerman msi_bitmap_free_hwirqs(&ppc4xx_hsta_msi.bmp, irq, 1);
116bfa9a2ebSMichael Ellerman pr_debug("%s: Teardown IRQ %u (index %u)\n", __func__,
117bfa9a2ebSMichael Ellerman entry->irq, irq);
1184545c6a3SMarc Zyngier entry->irq = 0;
119bfa9a2ebSMichael Ellerman }
120bfa9a2ebSMichael Ellerman }
121bfa9a2ebSMichael Ellerman
hsta_msi_probe(struct platform_device * pdev)122bfa9a2ebSMichael Ellerman static int hsta_msi_probe(struct platform_device *pdev)
123bfa9a2ebSMichael Ellerman {
124bfa9a2ebSMichael Ellerman struct device *dev = &pdev->dev;
125bfa9a2ebSMichael Ellerman struct resource *mem;
126bfa9a2ebSMichael Ellerman int irq, ret, irq_count;
127bfa9a2ebSMichael Ellerman struct pci_controller *phb;
128bfa9a2ebSMichael Ellerman
129bfa9a2ebSMichael Ellerman mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
130bfa9a2ebSMichael Ellerman if (!mem) {
131bfa9a2ebSMichael Ellerman dev_err(dev, "Unable to get mmio space\n");
132bfa9a2ebSMichael Ellerman return -EINVAL;
133bfa9a2ebSMichael Ellerman }
134bfa9a2ebSMichael Ellerman
135bfa9a2ebSMichael Ellerman irq_count = of_irq_count(dev->of_node);
136bfa9a2ebSMichael Ellerman if (!irq_count) {
137bfa9a2ebSMichael Ellerman dev_err(dev, "Unable to find IRQ range\n");
138bfa9a2ebSMichael Ellerman return -EINVAL;
139bfa9a2ebSMichael Ellerman }
140bfa9a2ebSMichael Ellerman
141bfa9a2ebSMichael Ellerman ppc4xx_hsta_msi.dev = dev;
142bfa9a2ebSMichael Ellerman ppc4xx_hsta_msi.address = mem->start;
143bfa9a2ebSMichael Ellerman ppc4xx_hsta_msi.data = ioremap(mem->start, resource_size(mem));
144bfa9a2ebSMichael Ellerman ppc4xx_hsta_msi.irq_count = irq_count;
145bfa9a2ebSMichael Ellerman if (!ppc4xx_hsta_msi.data) {
146bfa9a2ebSMichael Ellerman dev_err(dev, "Unable to map memory\n");
147bfa9a2ebSMichael Ellerman return -ENOMEM;
148bfa9a2ebSMichael Ellerman }
149bfa9a2ebSMichael Ellerman
150bfa9a2ebSMichael Ellerman ret = msi_bitmap_alloc(&ppc4xx_hsta_msi.bmp, irq_count, dev->of_node);
151bfa9a2ebSMichael Ellerman if (ret)
152bfa9a2ebSMichael Ellerman goto out;
153bfa9a2ebSMichael Ellerman
1546da2ec56SKees Cook ppc4xx_hsta_msi.irq_map = kmalloc_array(irq_count, sizeof(int),
1556da2ec56SKees Cook GFP_KERNEL);
156bfa9a2ebSMichael Ellerman if (!ppc4xx_hsta_msi.irq_map) {
157bfa9a2ebSMichael Ellerman ret = -ENOMEM;
158bfa9a2ebSMichael Ellerman goto out1;
159bfa9a2ebSMichael Ellerman }
160bfa9a2ebSMichael Ellerman
161bfa9a2ebSMichael Ellerman /* Setup a mapping from irq offsets to hardware irq numbers */
162bfa9a2ebSMichael Ellerman for (irq = 0; irq < irq_count; irq++) {
163bfa9a2ebSMichael Ellerman ppc4xx_hsta_msi.irq_map[irq] =
164bfa9a2ebSMichael Ellerman irq_of_parse_and_map(dev->of_node, irq);
165bfa9a2ebSMichael Ellerman if (!ppc4xx_hsta_msi.irq_map[irq]) {
166bfa9a2ebSMichael Ellerman dev_err(dev, "Unable to map IRQ\n");
167bfa9a2ebSMichael Ellerman ret = -EINVAL;
168bfa9a2ebSMichael Ellerman goto out2;
169bfa9a2ebSMichael Ellerman }
170bfa9a2ebSMichael Ellerman }
171bfa9a2ebSMichael Ellerman
172bfa9a2ebSMichael Ellerman list_for_each_entry(phb, &hose_list, list_node) {
173bfa9a2ebSMichael Ellerman phb->controller_ops.setup_msi_irqs = hsta_setup_msi_irqs;
174bfa9a2ebSMichael Ellerman phb->controller_ops.teardown_msi_irqs = hsta_teardown_msi_irqs;
175bfa9a2ebSMichael Ellerman }
176bfa9a2ebSMichael Ellerman return 0;
177bfa9a2ebSMichael Ellerman
178bfa9a2ebSMichael Ellerman out2:
179bfa9a2ebSMichael Ellerman kfree(ppc4xx_hsta_msi.irq_map);
180bfa9a2ebSMichael Ellerman
181bfa9a2ebSMichael Ellerman out1:
182bfa9a2ebSMichael Ellerman msi_bitmap_free(&ppc4xx_hsta_msi.bmp);
183bfa9a2ebSMichael Ellerman
184bfa9a2ebSMichael Ellerman out:
185bfa9a2ebSMichael Ellerman iounmap(ppc4xx_hsta_msi.data);
186bfa9a2ebSMichael Ellerman return ret;
187bfa9a2ebSMichael Ellerman }
188bfa9a2ebSMichael Ellerman
189bfa9a2ebSMichael Ellerman static const struct of_device_id hsta_msi_ids[] = {
190bfa9a2ebSMichael Ellerman {
191bfa9a2ebSMichael Ellerman .compatible = "ibm,hsta-msi",
192bfa9a2ebSMichael Ellerman },
193bfa9a2ebSMichael Ellerman {}
194bfa9a2ebSMichael Ellerman };
195bfa9a2ebSMichael Ellerman
196bfa9a2ebSMichael Ellerman static struct platform_driver hsta_msi_driver = {
197bfa9a2ebSMichael Ellerman .probe = hsta_msi_probe,
198bfa9a2ebSMichael Ellerman .driver = {
199bfa9a2ebSMichael Ellerman .name = "hsta-msi",
200bfa9a2ebSMichael Ellerman .of_match_table = hsta_msi_ids,
201bfa9a2ebSMichael Ellerman },
202bfa9a2ebSMichael Ellerman };
203bfa9a2ebSMichael Ellerman
hsta_msi_init(void)204bfa9a2ebSMichael Ellerman static int hsta_msi_init(void)
205bfa9a2ebSMichael Ellerman {
206bfa9a2ebSMichael Ellerman return platform_driver_register(&hsta_msi_driver);
207bfa9a2ebSMichael Ellerman }
208bfa9a2ebSMichael Ellerman subsys_initcall(hsta_msi_init);
209