1/*
2 * Support Hypertransport IRQ
3 *
4 * Copyright (C) 1997, 1998, 1999, 2000, 2009 Ingo Molnar, Hajnalka Szabo
5 *	Moved from arch/x86/kernel/apic/io_apic.c.
6 * Jiang Liu <jiang.liu@linux.intel.com>
7 *	Add support of hierarchical irqdomain
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12 */
13#include <linux/mm.h>
14#include <linux/interrupt.h>
15#include <linux/init.h>
16#include <linux/device.h>
17#include <linux/pci.h>
18#include <linux/htirq.h>
19#include <asm/irqdomain.h>
20#include <asm/hw_irq.h>
21#include <asm/apic.h>
22#include <asm/hypertransport.h>
23
24static struct irq_domain *htirq_domain;
25
26/*
27 * Hypertransport interrupt support
28 */
29static int
30ht_set_affinity(struct irq_data *data, const struct cpumask *mask, bool force)
31{
32	struct irq_data *parent = data->parent_data;
33	int ret;
34
35	ret = parent->chip->irq_set_affinity(parent, mask, force);
36	if (ret >= 0) {
37		struct ht_irq_msg msg;
38		struct irq_cfg *cfg = irqd_cfg(data);
39
40		fetch_ht_irq_msg(data->irq, &msg);
41		msg.address_lo &= ~(HT_IRQ_LOW_VECTOR_MASK |
42				    HT_IRQ_LOW_DEST_ID_MASK);
43		msg.address_lo |= HT_IRQ_LOW_VECTOR(cfg->vector) |
44				  HT_IRQ_LOW_DEST_ID(cfg->dest_apicid);
45		msg.address_hi &= ~(HT_IRQ_HIGH_DEST_ID_MASK);
46		msg.address_hi |= HT_IRQ_HIGH_DEST_ID(cfg->dest_apicid);
47		write_ht_irq_msg(data->irq, &msg);
48	}
49
50	return ret;
51}
52
53static struct irq_chip ht_irq_chip = {
54	.name			= "PCI-HT",
55	.irq_mask		= mask_ht_irq,
56	.irq_unmask		= unmask_ht_irq,
57	.irq_ack		= irq_chip_ack_parent,
58	.irq_set_affinity	= ht_set_affinity,
59	.irq_retrigger		= irq_chip_retrigger_hierarchy,
60	.flags			= IRQCHIP_SKIP_SET_WAKE,
61};
62
63static int htirq_domain_alloc(struct irq_domain *domain, unsigned int virq,
64			      unsigned int nr_irqs, void *arg)
65{
66	struct ht_irq_cfg *ht_cfg;
67	struct irq_alloc_info *info = arg;
68	struct pci_dev *dev;
69	irq_hw_number_t hwirq;
70	int ret;
71
72	if (nr_irqs > 1 || !info)
73		return -EINVAL;
74
75	dev = info->ht_dev;
76	hwirq = (info->ht_idx & 0xFF) |
77		PCI_DEVID(dev->bus->number, dev->devfn) << 8 |
78		(pci_domain_nr(dev->bus) & 0xFFFFFFFF) << 24;
79	if (irq_find_mapping(domain, hwirq) > 0)
80		return -EEXIST;
81
82	ht_cfg = kmalloc(sizeof(*ht_cfg), GFP_KERNEL);
83	if (!ht_cfg)
84		return -ENOMEM;
85
86	ret = irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, info);
87	if (ret < 0) {
88		kfree(ht_cfg);
89		return ret;
90	}
91
92	/* Initialize msg to a value that will never match the first write. */
93	ht_cfg->msg.address_lo = 0xffffffff;
94	ht_cfg->msg.address_hi = 0xffffffff;
95	ht_cfg->dev = info->ht_dev;
96	ht_cfg->update = info->ht_update;
97	ht_cfg->pos = info->ht_pos;
98	ht_cfg->idx = 0x10 + (info->ht_idx * 2);
99	irq_domain_set_info(domain, virq, hwirq, &ht_irq_chip, ht_cfg,
100			    handle_edge_irq, ht_cfg, "edge");
101
102	return 0;
103}
104
105static void htirq_domain_free(struct irq_domain *domain, unsigned int virq,
106			      unsigned int nr_irqs)
107{
108	struct irq_data *irq_data = irq_domain_get_irq_data(domain, virq);
109
110	BUG_ON(nr_irqs != 1);
111	kfree(irq_data->chip_data);
112	irq_domain_free_irqs_top(domain, virq, nr_irqs);
113}
114
115static void htirq_domain_activate(struct irq_domain *domain,
116				  struct irq_data *irq_data)
117{
118	struct ht_irq_msg msg;
119	struct irq_cfg *cfg = irqd_cfg(irq_data);
120
121	msg.address_hi = HT_IRQ_HIGH_DEST_ID(cfg->dest_apicid);
122	msg.address_lo =
123		HT_IRQ_LOW_BASE |
124		HT_IRQ_LOW_DEST_ID(cfg->dest_apicid) |
125		HT_IRQ_LOW_VECTOR(cfg->vector) |
126		((apic->irq_dest_mode == 0) ?
127			HT_IRQ_LOW_DM_PHYSICAL :
128			HT_IRQ_LOW_DM_LOGICAL) |
129		HT_IRQ_LOW_RQEOI_EDGE |
130		((apic->irq_delivery_mode != dest_LowestPrio) ?
131			HT_IRQ_LOW_MT_FIXED :
132			HT_IRQ_LOW_MT_ARBITRATED) |
133		HT_IRQ_LOW_IRQ_MASKED;
134	write_ht_irq_msg(irq_data->irq, &msg);
135}
136
137static void htirq_domain_deactivate(struct irq_domain *domain,
138				    struct irq_data *irq_data)
139{
140	struct ht_irq_msg msg;
141
142	memset(&msg, 0, sizeof(msg));
143	write_ht_irq_msg(irq_data->irq, &msg);
144}
145
146static const struct irq_domain_ops htirq_domain_ops = {
147	.alloc		= htirq_domain_alloc,
148	.free		= htirq_domain_free,
149	.activate	= htirq_domain_activate,
150	.deactivate	= htirq_domain_deactivate,
151};
152
153void arch_init_htirq_domain(struct irq_domain *parent)
154{
155	if (disable_apic)
156		return;
157
158	htirq_domain = irq_domain_add_tree(NULL, &htirq_domain_ops, NULL);
159	if (!htirq_domain)
160		pr_warn("failed to initialize irqdomain for HTIRQ.\n");
161	else
162		htirq_domain->parent = parent;
163}
164
165int arch_setup_ht_irq(int idx, int pos, struct pci_dev *dev,
166		      ht_irq_update_t *update)
167{
168	struct irq_alloc_info info;
169
170	if (!htirq_domain)
171		return -ENOSYS;
172
173	init_irq_alloc_info(&info, NULL);
174	info.ht_idx = idx;
175	info.ht_pos = pos;
176	info.ht_dev = dev;
177	info.ht_update = update;
178
179	return irq_domain_alloc_irqs(htirq_domain, 1, dev_to_node(&dev->dev),
180				     &info);
181}
182
183void arch_teardown_ht_irq(unsigned int irq)
184{
185	irq_domain_free_irqs(irq, 1);
186}
187