xref: /openbmc/linux/arch/x86/platform/uv/uv_irq.c (revision 6c33a6f4)
1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file "COPYING" in the main directory of this archive
4  * for more details.
5  *
6  * SGI UV IRQ functions
7  *
8  * Copyright (C) 2008 Silicon Graphics, Inc. All rights reserved.
9  */
10 
11 #include <linux/export.h>
12 #include <linux/rbtree.h>
13 #include <linux/slab.h>
14 #include <linux/irq.h>
15 
16 #include <asm/irqdomain.h>
17 #include <asm/apic.h>
18 #include <asm/uv/uv_irq.h>
19 #include <asm/uv/uv_hub.h>
20 
21 /* MMR offset and pnode of hub sourcing interrupts for a given irq */
22 struct uv_irq_2_mmr_pnode {
23 	unsigned long		offset;
24 	int			pnode;
25 };
26 
27 static void uv_program_mmr(struct irq_cfg *cfg, struct uv_irq_2_mmr_pnode *info)
28 {
29 	unsigned long mmr_value;
30 	struct uv_IO_APIC_route_entry *entry;
31 
32 	BUILD_BUG_ON(sizeof(struct uv_IO_APIC_route_entry) !=
33 		     sizeof(unsigned long));
34 
35 	mmr_value = 0;
36 	entry = (struct uv_IO_APIC_route_entry *)&mmr_value;
37 	entry->vector		= cfg->vector;
38 	entry->delivery_mode	= apic->irq_delivery_mode;
39 	entry->dest_mode	= apic->irq_dest_mode;
40 	entry->polarity		= 0;
41 	entry->trigger		= 0;
42 	entry->mask		= 0;
43 	entry->dest		= cfg->dest_apicid;
44 
45 	uv_write_global_mmr64(info->pnode, info->offset, mmr_value);
46 }
47 
48 static void uv_noop(struct irq_data *data) { }
49 
50 static int
51 uv_set_irq_affinity(struct irq_data *data, const struct cpumask *mask,
52 		    bool force)
53 {
54 	struct irq_data *parent = data->parent_data;
55 	struct irq_cfg *cfg = irqd_cfg(data);
56 	int ret;
57 
58 	ret = parent->chip->irq_set_affinity(parent, mask, force);
59 	if (ret >= 0) {
60 		uv_program_mmr(cfg, data->chip_data);
61 		send_cleanup_vector(cfg);
62 	}
63 
64 	return ret;
65 }
66 
67 static struct irq_chip uv_irq_chip = {
68 	.name			= "UV-CORE",
69 	.irq_mask		= uv_noop,
70 	.irq_unmask		= uv_noop,
71 	.irq_eoi		= apic_ack_irq,
72 	.irq_set_affinity	= uv_set_irq_affinity,
73 };
74 
75 static int uv_domain_alloc(struct irq_domain *domain, unsigned int virq,
76 			   unsigned int nr_irqs, void *arg)
77 {
78 	struct uv_irq_2_mmr_pnode *chip_data;
79 	struct irq_alloc_info *info = arg;
80 	struct irq_data *irq_data = irq_domain_get_irq_data(domain, virq);
81 	int ret;
82 
83 	if (nr_irqs > 1 || !info || info->type != X86_IRQ_ALLOC_TYPE_UV)
84 		return -EINVAL;
85 
86 	chip_data = kmalloc_node(sizeof(*chip_data), GFP_KERNEL,
87 				 irq_data_get_node(irq_data));
88 	if (!chip_data)
89 		return -ENOMEM;
90 
91 	ret = irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, arg);
92 	if (ret >= 0) {
93 		if (info->uv_limit == UV_AFFINITY_CPU)
94 			irq_set_status_flags(virq, IRQ_NO_BALANCING);
95 		else
96 			irq_set_status_flags(virq, IRQ_MOVE_PCNTXT);
97 
98 		chip_data->pnode = uv_blade_to_pnode(info->uv_blade);
99 		chip_data->offset = info->uv_offset;
100 		irq_domain_set_info(domain, virq, virq, &uv_irq_chip, chip_data,
101 				    handle_percpu_irq, NULL, info->uv_name);
102 	} else {
103 		kfree(chip_data);
104 	}
105 
106 	return ret;
107 }
108 
109 static void uv_domain_free(struct irq_domain *domain, unsigned int virq,
110 			   unsigned int nr_irqs)
111 {
112 	struct irq_data *irq_data = irq_domain_get_irq_data(domain, virq);
113 
114 	BUG_ON(nr_irqs != 1);
115 	kfree(irq_data->chip_data);
116 	irq_clear_status_flags(virq, IRQ_MOVE_PCNTXT);
117 	irq_clear_status_flags(virq, IRQ_NO_BALANCING);
118 	irq_domain_free_irqs_top(domain, virq, nr_irqs);
119 }
120 
121 /*
122  * Re-target the irq to the specified CPU and enable the specified MMR located
123  * on the specified blade to allow the sending of MSIs to the specified CPU.
124  */
125 static int uv_domain_activate(struct irq_domain *domain,
126 			      struct irq_data *irq_data, bool reserve)
127 {
128 	uv_program_mmr(irqd_cfg(irq_data), irq_data->chip_data);
129 	return 0;
130 }
131 
132 /*
133  * Disable the specified MMR located on the specified blade so that MSIs are
134  * longer allowed to be sent.
135  */
136 static void uv_domain_deactivate(struct irq_domain *domain,
137 				 struct irq_data *irq_data)
138 {
139 	unsigned long mmr_value;
140 	struct uv_IO_APIC_route_entry *entry;
141 
142 	mmr_value = 0;
143 	entry = (struct uv_IO_APIC_route_entry *)&mmr_value;
144 	entry->mask = 1;
145 	uv_program_mmr(irqd_cfg(irq_data), irq_data->chip_data);
146 }
147 
148 static const struct irq_domain_ops uv_domain_ops = {
149 	.alloc		= uv_domain_alloc,
150 	.free		= uv_domain_free,
151 	.activate	= uv_domain_activate,
152 	.deactivate	= uv_domain_deactivate,
153 };
154 
155 static struct irq_domain *uv_get_irq_domain(void)
156 {
157 	static struct irq_domain *uv_domain;
158 	static DEFINE_MUTEX(uv_lock);
159 	struct fwnode_handle *fn;
160 
161 	mutex_lock(&uv_lock);
162 	if (uv_domain)
163 		goto out;
164 
165 	fn = irq_domain_alloc_named_fwnode("UV-CORE");
166 	if (!fn)
167 		goto out;
168 
169 	uv_domain = irq_domain_create_tree(fn, &uv_domain_ops, NULL);
170 	irq_domain_free_fwnode(fn);
171 	if (uv_domain)
172 		uv_domain->parent = x86_vector_domain;
173 out:
174 	mutex_unlock(&uv_lock);
175 
176 	return uv_domain;
177 }
178 
179 /*
180  * Set up a mapping of an available irq and vector, and enable the specified
181  * MMR that defines the MSI that is to be sent to the specified CPU when an
182  * interrupt is raised.
183  */
184 int uv_setup_irq(char *irq_name, int cpu, int mmr_blade,
185 		 unsigned long mmr_offset, int limit)
186 {
187 	struct irq_alloc_info info;
188 	struct irq_domain *domain = uv_get_irq_domain();
189 
190 	if (!domain)
191 		return -ENOMEM;
192 
193 	init_irq_alloc_info(&info, cpumask_of(cpu));
194 	info.type = X86_IRQ_ALLOC_TYPE_UV;
195 	info.uv_limit = limit;
196 	info.uv_blade = mmr_blade;
197 	info.uv_offset = mmr_offset;
198 	info.uv_name = irq_name;
199 
200 	return irq_domain_alloc_irqs(domain, 1,
201 				     uv_blade_to_memory_nid(mmr_blade), &info);
202 }
203 EXPORT_SYMBOL_GPL(uv_setup_irq);
204 
205 /*
206  * Tear down a mapping of an irq and vector, and disable the specified MMR that
207  * defined the MSI that was to be sent to the specified CPU when an interrupt
208  * was raised.
209  *
210  * Set mmr_blade and mmr_offset to what was passed in on uv_setup_irq().
211  */
212 void uv_teardown_irq(unsigned int irq)
213 {
214 	irq_domain_free_irqs(irq, 1);
215 }
216 EXPORT_SYMBOL_GPL(uv_teardown_irq);
217