1/*
2 * Copyright 2006, Segher Boessenkool, IBM Corporation.
3 * Copyright 2006-2007, Michael Ellerman, IBM Corporation.
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License
7 * as published by the Free Software Foundation; version 2 of the
8 * License.
9 *
10 */
11
12#include <linux/irq.h>
13#include <linux/bootmem.h>
14#include <linux/msi.h>
15#include <asm/mpic.h>
16#include <asm/prom.h>
17#include <asm/hw_irq.h>
18#include <asm/ppc-pci.h>
19
20#include "mpic.h"
21
22/* A bit ugly, can we get this from the pci_dev somehow? */
23static struct mpic *msi_mpic;
24
25static void mpic_u3msi_mask_irq(unsigned int irq)
26{
27	mask_msi_irq(irq);
28	mpic_mask_irq(irq);
29}
30
31static void mpic_u3msi_unmask_irq(unsigned int irq)
32{
33	mpic_unmask_irq(irq);
34	unmask_msi_irq(irq);
35}
36
37static struct irq_chip mpic_u3msi_chip = {
38	.shutdown	= mpic_u3msi_mask_irq,
39	.mask		= mpic_u3msi_mask_irq,
40	.unmask		= mpic_u3msi_unmask_irq,
41	.eoi		= mpic_end_irq,
42	.set_type	= mpic_set_irq_type,
43	.typename	= "MPIC-U3MSI",
44};
45
46static u64 read_ht_magic_addr(struct pci_dev *pdev, unsigned int pos)
47{
48	u8 flags;
49	u32 tmp;
50	u64 addr;
51
52	pci_read_config_byte(pdev, pos + HT_MSI_FLAGS, &flags);
53
54	if (flags & HT_MSI_FLAGS_FIXED)
55		return HT_MSI_FIXED_ADDR;
56
57	pci_read_config_dword(pdev, pos + HT_MSI_ADDR_LO, &tmp);
58	addr = tmp & HT_MSI_ADDR_LO_MASK;
59	pci_read_config_dword(pdev, pos + HT_MSI_ADDR_HI, &tmp);
60	addr = addr | ((u64)tmp << 32);
61
62	return addr;
63}
64
65static u64 find_ht_magic_addr(struct pci_dev *pdev)
66{
67	struct pci_bus *bus;
68	unsigned int pos;
69
70	for (bus = pdev->bus; bus; bus = bus->parent) {
71		pos = pci_find_ht_capability(bus->self, HT_CAPTYPE_MSI_MAPPING);
72		if (pos)
73			return read_ht_magic_addr(bus->self, pos);
74	}
75
76	return 0;
77}
78
79static int u3msi_msi_check_device(struct pci_dev *pdev, int nvec, int type)
80{
81	if (type == PCI_CAP_ID_MSIX)
82		pr_debug("u3msi: MSI-X untested, trying anyway.\n");
83
84	/* If we can't find a magic address then MSI ain't gonna work */
85	if (find_ht_magic_addr(pdev) == 0) {
86		pr_debug("u3msi: no magic address found for %s\n",
87			 pci_name(pdev));
88		return -ENXIO;
89	}
90
91	return 0;
92}
93
94static void u3msi_teardown_msi_irqs(struct pci_dev *pdev)
95{
96	struct msi_desc *entry;
97
98        list_for_each_entry(entry, &pdev->msi_list, list) {
99		if (entry->irq == NO_IRQ)
100			continue;
101
102		set_irq_msi(entry->irq, NULL);
103		mpic_msi_free_hwirqs(msi_mpic, virq_to_hw(entry->irq), 1);
104		irq_dispose_mapping(entry->irq);
105	}
106
107	return;
108}
109
110static void u3msi_compose_msi_msg(struct pci_dev *pdev, int virq,
111				  struct msi_msg *msg)
112{
113	u64 addr;
114
115	addr = find_ht_magic_addr(pdev);
116	msg->address_lo = addr & 0xFFFFFFFF;
117	msg->address_hi = addr >> 32;
118	msg->data = virq_to_hw(virq);
119
120	pr_debug("u3msi: allocated virq 0x%x (hw 0x%lx) at address 0x%lx\n",
121		 virq, virq_to_hw(virq), addr);
122}
123
124static int u3msi_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
125{
126	irq_hw_number_t hwirq;
127	int rc;
128	unsigned int virq;
129	struct msi_desc *entry;
130	struct msi_msg msg;
131
132	list_for_each_entry(entry, &pdev->msi_list, list) {
133		hwirq = mpic_msi_alloc_hwirqs(msi_mpic, 1);
134		if (hwirq < 0) {
135			rc = hwirq;
136			pr_debug("u3msi: failed allocating hwirq\n");
137			goto out_free;
138		}
139
140		virq = irq_create_mapping(msi_mpic->irqhost, hwirq);
141		if (virq == NO_IRQ) {
142			pr_debug("u3msi: failed mapping hwirq 0x%lx\n", hwirq);
143			mpic_msi_free_hwirqs(msi_mpic, hwirq, 1);
144			rc = -ENOSPC;
145			goto out_free;
146		}
147
148		set_irq_msi(virq, entry);
149		set_irq_chip(virq, &mpic_u3msi_chip);
150		set_irq_type(virq, IRQ_TYPE_EDGE_RISING);
151
152		u3msi_compose_msi_msg(pdev, virq, &msg);
153		write_msi_msg(virq, &msg);
154
155		hwirq++;
156	}
157
158	return 0;
159
160 out_free:
161	u3msi_teardown_msi_irqs(pdev);
162	return rc;
163}
164
165int mpic_u3msi_init(struct mpic *mpic)
166{
167	int rc;
168
169	rc = mpic_msi_init_allocator(mpic);
170	if (rc) {
171		pr_debug("u3msi: Error allocating bitmap!\n");
172		return rc;
173	}
174
175	pr_debug("u3msi: Registering MPIC U3 MSI callbacks.\n");
176
177	BUG_ON(msi_mpic);
178	msi_mpic = mpic;
179
180	WARN_ON(ppc_md.setup_msi_irqs);
181	ppc_md.setup_msi_irqs = u3msi_setup_msi_irqs;
182	ppc_md.teardown_msi_irqs = u3msi_teardown_msi_irqs;
183	ppc_md.msi_check_device = u3msi_msi_check_device;
184
185	return 0;
186}
187