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e2c37d90 AP |
1 | /* |
2 | * MSI support for PPC4xx SoCs using High Speed Transfer Assist (HSTA) for | |
3 | * generation of the interrupt. | |
4 | * | |
5 | * Copyright © 2013 Alistair Popple <alistair@popple.id.au> IBM Corporation | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify it | |
8 | * under the terms of the GNU General Public License as published by the | |
9 | * Free Software Foundation; either version 2 of the License, or (at your | |
10 | * option) any later version. | |
11 | */ | |
12 | ||
13 | #include <linux/kernel.h> | |
14 | #include <linux/interrupt.h> | |
15 | #include <linux/msi.h> | |
16 | #include <linux/of.h> | |
17 | #include <linux/of_platform.h> | |
18 | #include <linux/pci.h> | |
19 | #include <linux/semaphore.h> | |
20 | #include <asm/msi_bitmap.h> | |
aaf6fd5c | 21 | #include <asm/ppc-pci.h> |
e2c37d90 AP |
22 | |
23 | struct ppc4xx_hsta_msi { | |
24 | struct device *dev; | |
25 | ||
26 | /* The ioremapped HSTA MSI IO space */ | |
27 | u32 __iomem *data; | |
28 | ||
29 | /* Physical address of HSTA MSI IO space */ | |
30 | u64 address; | |
31 | struct msi_bitmap bmp; | |
32 | ||
33 | /* An array mapping offsets to hardware IRQs */ | |
34 | int *irq_map; | |
35 | ||
36 | /* Number of hwirqs supported */ | |
37 | int irq_count; | |
38 | }; | |
39 | static struct ppc4xx_hsta_msi ppc4xx_hsta_msi; | |
40 | ||
41 | static int hsta_setup_msi_irqs(struct pci_dev *dev, int nvec, int type) | |
42 | { | |
43 | struct msi_msg msg; | |
44 | struct msi_desc *entry; | |
45 | int irq, hwirq; | |
46 | u64 addr; | |
47 | ||
6b2fd7ef AG |
48 | /* We don't support MSI-X */ |
49 | if (type == PCI_CAP_ID_MSIX) { | |
50 | pr_debug("%s: MSI-X not supported.\n", __func__); | |
51 | return -EINVAL; | |
52 | } | |
53 | ||
2921d179 | 54 | for_each_pci_msi_entry(entry, dev) { |
e2c37d90 AP |
55 | irq = msi_bitmap_alloc_hwirqs(&ppc4xx_hsta_msi.bmp, 1); |
56 | if (irq < 0) { | |
57 | pr_debug("%s: Failed to allocate msi interrupt\n", | |
58 | __func__); | |
59 | return irq; | |
60 | } | |
61 | ||
62 | hwirq = ppc4xx_hsta_msi.irq_map[irq]; | |
63 | if (hwirq == NO_IRQ) { | |
64 | pr_err("%s: Failed mapping irq %d\n", __func__, irq); | |
65 | return -EINVAL; | |
66 | } | |
67 | ||
68 | /* | |
69 | * HSTA generates interrupts on writes to 128-bit aligned | |
70 | * addresses. | |
71 | */ | |
72 | addr = ppc4xx_hsta_msi.address + irq*0x10; | |
73 | msg.address_hi = upper_32_bits(addr); | |
74 | msg.address_lo = lower_32_bits(addr); | |
75 | ||
76 | /* Data is not used by the HSTA. */ | |
77 | msg.data = 0; | |
78 | ||
79 | pr_debug("%s: Setup irq %d (0x%0llx)\n", __func__, hwirq, | |
80 | (((u64) msg.address_hi) << 32) | msg.address_lo); | |
81 | ||
82 | if (irq_set_msi_desc(hwirq, entry)) { | |
83 | pr_err( | |
84 | "%s: Invalid hwirq %d specified in device tree\n", | |
85 | __func__, hwirq); | |
86 | msi_bitmap_free_hwirqs(&ppc4xx_hsta_msi.bmp, irq, 1); | |
87 | return -EINVAL; | |
88 | } | |
83a18912 | 89 | pci_write_msi_msg(hwirq, &msg); |
e2c37d90 AP |
90 | } |
91 | ||
92 | return 0; | |
93 | } | |
94 | ||
95 | static int hsta_find_hwirq_offset(int hwirq) | |
96 | { | |
97 | int irq; | |
98 | ||
99 | /* Find the offset given the hwirq */ | |
100 | for (irq = 0; irq < ppc4xx_hsta_msi.irq_count; irq++) | |
101 | if (ppc4xx_hsta_msi.irq_map[irq] == hwirq) | |
102 | return irq; | |
103 | ||
104 | return -EINVAL; | |
105 | } | |
106 | ||
107 | static void hsta_teardown_msi_irqs(struct pci_dev *dev) | |
108 | { | |
109 | struct msi_desc *entry; | |
110 | int irq; | |
111 | ||
2921d179 | 112 | for_each_pci_msi_entry(entry, dev) { |
e2c37d90 AP |
113 | if (entry->irq == NO_IRQ) |
114 | continue; | |
115 | ||
116 | irq = hsta_find_hwirq_offset(entry->irq); | |
117 | ||
118 | /* entry->irq should always be in irq_map */ | |
119 | BUG_ON(irq < 0); | |
120 | irq_set_msi_desc(entry->irq, NULL); | |
121 | msi_bitmap_free_hwirqs(&ppc4xx_hsta_msi.bmp, irq, 1); | |
122 | pr_debug("%s: Teardown IRQ %u (index %u)\n", __func__, | |
123 | entry->irq, irq); | |
124 | } | |
125 | } | |
126 | ||
e2c37d90 AP |
127 | static int hsta_msi_probe(struct platform_device *pdev) |
128 | { | |
129 | struct device *dev = &pdev->dev; | |
130 | struct resource *mem; | |
131 | int irq, ret, irq_count; | |
f2c800aa | 132 | struct pci_controller *phb; |
e2c37d90 AP |
133 | |
134 | mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
35a7f41c | 135 | if (!mem) { |
e2c37d90 AP |
136 | dev_err(dev, "Unable to get mmio space\n"); |
137 | return -EINVAL; | |
138 | } | |
139 | ||
140 | irq_count = of_irq_count(dev->of_node); | |
141 | if (!irq_count) { | |
142 | dev_err(dev, "Unable to find IRQ range\n"); | |
143 | return -EINVAL; | |
144 | } | |
145 | ||
146 | ppc4xx_hsta_msi.dev = dev; | |
147 | ppc4xx_hsta_msi.address = mem->start; | |
148 | ppc4xx_hsta_msi.data = ioremap(mem->start, resource_size(mem)); | |
149 | ppc4xx_hsta_msi.irq_count = irq_count; | |
e144d4ed | 150 | if (!ppc4xx_hsta_msi.data) { |
e2c37d90 AP |
151 | dev_err(dev, "Unable to map memory\n"); |
152 | return -ENOMEM; | |
153 | } | |
154 | ||
155 | ret = msi_bitmap_alloc(&ppc4xx_hsta_msi.bmp, irq_count, dev->of_node); | |
156 | if (ret) | |
157 | goto out; | |
158 | ||
159 | ppc4xx_hsta_msi.irq_map = kmalloc(sizeof(int) * irq_count, GFP_KERNEL); | |
35a7f41c | 160 | if (!ppc4xx_hsta_msi.irq_map) { |
e2c37d90 AP |
161 | ret = -ENOMEM; |
162 | goto out1; | |
163 | } | |
164 | ||
165 | /* Setup a mapping from irq offsets to hardware irq numbers */ | |
166 | for (irq = 0; irq < irq_count; irq++) { | |
167 | ppc4xx_hsta_msi.irq_map[irq] = | |
168 | irq_of_parse_and_map(dev->of_node, irq); | |
169 | if (ppc4xx_hsta_msi.irq_map[irq] == NO_IRQ) { | |
170 | dev_err(dev, "Unable to map IRQ\n"); | |
171 | ret = -EINVAL; | |
172 | goto out2; | |
173 | } | |
174 | } | |
175 | ||
f2c800aa DA |
176 | list_for_each_entry(phb, &hose_list, list_node) { |
177 | phb->controller_ops.setup_msi_irqs = hsta_setup_msi_irqs; | |
178 | phb->controller_ops.teardown_msi_irqs = hsta_teardown_msi_irqs; | |
179 | } | |
e2c37d90 AP |
180 | return 0; |
181 | ||
182 | out2: | |
183 | kfree(ppc4xx_hsta_msi.irq_map); | |
184 | ||
185 | out1: | |
186 | msi_bitmap_free(&ppc4xx_hsta_msi.bmp); | |
187 | ||
188 | out: | |
189 | iounmap(ppc4xx_hsta_msi.data); | |
190 | return ret; | |
191 | } | |
192 | ||
193 | static const struct of_device_id hsta_msi_ids[] = { | |
194 | { | |
195 | .compatible = "ibm,hsta-msi", | |
196 | }, | |
197 | {} | |
198 | }; | |
199 | ||
200 | static struct platform_driver hsta_msi_driver = { | |
201 | .probe = hsta_msi_probe, | |
202 | .driver = { | |
203 | .name = "hsta-msi", | |
e2c37d90 AP |
204 | .of_match_table = hsta_msi_ids, |
205 | }, | |
206 | }; | |
207 | ||
208 | static int hsta_msi_init(void) | |
209 | { | |
210 | return platform_driver_register(&hsta_msi_driver); | |
211 | } | |
212 | subsys_initcall(hsta_msi_init); |