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 */
22struct uv_irq_2_mmr_pnode {
23	unsigned long		offset;
24	int			pnode;
25};
26
27static 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_DELIVERY_MODE_FIXED;
39	entry->dest_mode	= apic->dest_mode_logical;
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
48static void uv_noop(struct irq_data *data) { }
49
50static int
51uv_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		vector_schedule_cleanup(cfg);
62	}
63
64	return ret;
65}
66
67static 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
75static 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
109static 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 */
125static 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 */
136static 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
148static 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
155static 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_hierarchy(x86_vector_domain, 0, 0, fn,
170						&uv_domain_ops, NULL);
171	if (!uv_domain)
172		irq_domain_free_fwnode(fn);
173out:
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 */
184int 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}
203EXPORT_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 */
212void uv_teardown_irq(unsigned int irq)
213{
214	irq_domain_free_irqs(irq, 1);
215}
216EXPORT_SYMBOL_GPL(uv_teardown_irq);
217