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6
7#define pr_fmt(fmt) "pch-msi: " fmt
8
9#include <linux/irqchip.h>
10#include <linux/msi.h>
11#include <linux/of.h>
12#include <linux/of_address.h>
13#include <linux/of_irq.h>
14#include <linux/of_pci.h>
15#include <linux/pci.h>
16#include <linux/slab.h>
17
18struct pch_msi_data {
19 struct mutex msi_map_lock;
20 phys_addr_t doorbell;
21 u32 irq_first;
22 u32 num_irqs;
23 unsigned long *msi_map;
24};
25
26static void pch_msi_mask_msi_irq(struct irq_data *d)
27{
28 pci_msi_mask_irq(d);
29 irq_chip_mask_parent(d);
30}
31
32static void pch_msi_unmask_msi_irq(struct irq_data *d)
33{
34 irq_chip_unmask_parent(d);
35 pci_msi_unmask_irq(d);
36}
37
38static struct irq_chip pch_msi_irq_chip = {
39 .name = "PCH PCI MSI",
40 .irq_mask = pch_msi_mask_msi_irq,
41 .irq_unmask = pch_msi_unmask_msi_irq,
42 .irq_ack = irq_chip_ack_parent,
43 .irq_set_affinity = irq_chip_set_affinity_parent,
44};
45
46static int pch_msi_allocate_hwirq(struct pch_msi_data *priv, int num_req)
47{
48 int first;
49
50 mutex_lock(&priv->msi_map_lock);
51
52 first = bitmap_find_free_region(priv->msi_map, priv->num_irqs,
53 get_count_order(num_req));
54 if (first < 0) {
55 mutex_unlock(&priv->msi_map_lock);
56 return -ENOSPC;
57 }
58
59 mutex_unlock(&priv->msi_map_lock);
60
61 return priv->irq_first + first;
62}
63
64static void pch_msi_free_hwirq(struct pch_msi_data *priv,
65 int hwirq, int num_req)
66{
67 int first = hwirq - priv->irq_first;
68
69 mutex_lock(&priv->msi_map_lock);
70 bitmap_release_region(priv->msi_map, first, get_count_order(num_req));
71 mutex_unlock(&priv->msi_map_lock);
72}
73
74static void pch_msi_compose_msi_msg(struct irq_data *data,
75 struct msi_msg *msg)
76{
77 struct pch_msi_data *priv = irq_data_get_irq_chip_data(data);
78
79 msg->address_hi = upper_32_bits(priv->doorbell);
80 msg->address_lo = lower_32_bits(priv->doorbell);
81 msg->data = data->hwirq;
82}
83
84static struct msi_domain_info pch_msi_domain_info = {
85 .flags = MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
86 MSI_FLAG_MULTI_PCI_MSI | MSI_FLAG_PCI_MSIX,
87 .chip = &pch_msi_irq_chip,
88};
89
90static struct irq_chip middle_irq_chip = {
91 .name = "PCH MSI",
92 .irq_mask = irq_chip_mask_parent,
93 .irq_unmask = irq_chip_unmask_parent,
94 .irq_ack = irq_chip_ack_parent,
95 .irq_set_affinity = irq_chip_set_affinity_parent,
96 .irq_compose_msi_msg = pch_msi_compose_msi_msg,
97};
98
99static int pch_msi_parent_domain_alloc(struct irq_domain *domain,
100 unsigned int virq, int hwirq)
101{
102 struct irq_fwspec fwspec;
103
104 fwspec.fwnode = domain->parent->fwnode;
105 fwspec.param_count = 1;
106 fwspec.param[0] = hwirq;
107
108 return irq_domain_alloc_irqs_parent(domain, virq, 1, &fwspec);
109}
110
111static int pch_msi_middle_domain_alloc(struct irq_domain *domain,
112 unsigned int virq,
113 unsigned int nr_irqs, void *args)
114{
115 struct pch_msi_data *priv = domain->host_data;
116 int hwirq, err, i;
117
118 hwirq = pch_msi_allocate_hwirq(priv, nr_irqs);
119 if (hwirq < 0)
120 return hwirq;
121
122 for (i = 0; i < nr_irqs; i++) {
123 err = pch_msi_parent_domain_alloc(domain, virq + i, hwirq + i);
124 if (err)
125 goto err_hwirq;
126
127 irq_domain_set_hwirq_and_chip(domain, virq + i, hwirq + i,
128 &middle_irq_chip, priv);
129 }
130
131 return 0;
132
133err_hwirq:
134 pch_msi_free_hwirq(priv, hwirq, nr_irqs);
135 irq_domain_free_irqs_parent(domain, virq, i - 1);
136
137 return err;
138}
139
140static void pch_msi_middle_domain_free(struct irq_domain *domain,
141 unsigned int virq,
142 unsigned int nr_irqs)
143{
144 struct irq_data *d = irq_domain_get_irq_data(domain, virq);
145 struct pch_msi_data *priv = irq_data_get_irq_chip_data(d);
146
147 irq_domain_free_irqs_parent(domain, virq, nr_irqs);
148 pch_msi_free_hwirq(priv, d->hwirq, nr_irqs);
149}
150
151static const struct irq_domain_ops pch_msi_middle_domain_ops = {
152 .alloc = pch_msi_middle_domain_alloc,
153 .free = pch_msi_middle_domain_free,
154};
155
156static int pch_msi_init_domains(struct pch_msi_data *priv,
157 struct device_node *node,
158 struct irq_domain *parent)
159{
160 struct irq_domain *middle_domain, *msi_domain;
161
162 middle_domain = irq_domain_create_linear(of_node_to_fwnode(node),
163 priv->num_irqs,
164 &pch_msi_middle_domain_ops,
165 priv);
166 if (!middle_domain) {
167 pr_err("Failed to create the MSI middle domain\n");
168 return -ENOMEM;
169 }
170
171 middle_domain->parent = parent;
172 irq_domain_update_bus_token(middle_domain, DOMAIN_BUS_NEXUS);
173
174 msi_domain = pci_msi_create_irq_domain(of_node_to_fwnode(node),
175 &pch_msi_domain_info,
176 middle_domain);
177 if (!msi_domain) {
178 pr_err("Failed to create PCI MSI domain\n");
179 irq_domain_remove(middle_domain);
180 return -ENOMEM;
181 }
182
183 return 0;
184}
185
186static int pch_msi_init(struct device_node *node,
187 struct device_node *parent)
188{
189 struct pch_msi_data *priv;
190 struct irq_domain *parent_domain;
191 struct resource res;
192 int ret;
193
194 parent_domain = irq_find_host(parent);
195 if (!parent_domain) {
196 pr_err("Failed to find the parent domain\n");
197 return -ENXIO;
198 }
199
200 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
201 if (!priv)
202 return -ENOMEM;
203
204 mutex_init(&priv->msi_map_lock);
205
206 ret = of_address_to_resource(node, 0, &res);
207 if (ret) {
208 pr_err("Failed to allocate resource\n");
209 goto err_priv;
210 }
211
212 priv->doorbell = res.start;
213
214 if (of_property_read_u32(node, "loongson,msi-base-vec",
215 &priv->irq_first)) {
216 pr_err("Unable to parse MSI vec base\n");
217 ret = -EINVAL;
218 goto err_priv;
219 }
220
221 if (of_property_read_u32(node, "loongson,msi-num-vecs",
222 &priv->num_irqs)) {
223 pr_err("Unable to parse MSI vec number\n");
224 ret = -EINVAL;
225 goto err_priv;
226 }
227
228 priv->msi_map = bitmap_alloc(priv->num_irqs, GFP_KERNEL);
229 if (!priv->msi_map) {
230 ret = -ENOMEM;
231 goto err_priv;
232 }
233
234 pr_debug("Registering %d MSIs, starting at %d\n",
235 priv->num_irqs, priv->irq_first);
236
237 ret = pch_msi_init_domains(priv, node, parent_domain);
238 if (ret)
239 goto err_map;
240
241 return 0;
242
243err_map:
244 kfree(priv->msi_map);
245err_priv:
246 kfree(priv);
247 return ret;
248}
249
250IRQCHIP_DECLARE(pch_msi, "loongson,pch-msi-1.0", pch_msi_init);
251
