tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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 .set_affinity = mpic_set_affinity,
44 .typename = "MPIC-U3MSI",
45};
46
47static u64 read_ht_magic_addr(struct pci_dev *pdev, unsigned int pos)
48{
49 u8 flags;
50 u32 tmp;
51 u64 addr;
52
53 pci_read_config_byte(pdev, pos + HT_MSI_FLAGS, &flags);
54
55 if (flags & HT_MSI_FLAGS_FIXED)
56 return HT_MSI_FIXED_ADDR;
57
58 pci_read_config_dword(pdev, pos + HT_MSI_ADDR_LO, &tmp);
59 addr = tmp & HT_MSI_ADDR_LO_MASK;
60 pci_read_config_dword(pdev, pos + HT_MSI_ADDR_HI, &tmp);
61 addr = addr | ((u64)tmp << 32);
62
63 return addr;
64}
65
66static u64 find_ht_magic_addr(struct pci_dev *pdev)
67{
68 struct pci_bus *bus;
69 unsigned int pos;
70
71 for (bus = pdev->bus; bus; bus = bus->parent) {
72 pos = pci_find_ht_capability(bus->self, HT_CAPTYPE_MSI_MAPPING);
73 if (pos)
74 return read_ht_magic_addr(bus->self, pos);
75 }
76
77 return 0;
78}
79
80static int u3msi_msi_check_device(struct pci_dev *pdev, int nvec, int type)
81{
82 if (type == PCI_CAP_ID_MSIX)
83 pr_debug("u3msi: MSI-X untested, trying anyway.\n");
84
85 /* If we can't find a magic address then MSI ain't gonna work */
86 if (find_ht_magic_addr(pdev) == 0) {
87 pr_debug("u3msi: no magic address found for %s\n",
88 pci_name(pdev));
89 return -ENXIO;
90 }
91
92 return 0;
93}
94
95static void u3msi_teardown_msi_irqs(struct pci_dev *pdev)
96{
97 struct msi_desc *entry;
98
99 list_for_each_entry(entry, &pdev->msi_list, list) {
100 if (entry->irq == NO_IRQ)
101 continue;
102
103 set_irq_msi(entry->irq, NULL);
104 mpic_msi_free_hwirqs(msi_mpic, virq_to_hw(entry->irq), 1);
105 irq_dispose_mapping(entry->irq);
106 }
107
108 return;
109}
110
111static int u3msi_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
112{
113 irq_hw_number_t hwirq;
114 unsigned int virq;
115 struct msi_desc *entry;
116 struct msi_msg msg;
117 u64 addr;
118
119 addr = find_ht_magic_addr(pdev);
120 msg.address_lo = addr & 0xFFFFFFFF;
121 msg.address_hi = addr >> 32;
122
123 list_for_each_entry(entry, &pdev->msi_list, list) {
124 hwirq = mpic_msi_alloc_hwirqs(msi_mpic, 1);
125 if (hwirq < 0) {
126 pr_debug("u3msi: failed allocating hwirq\n");
127 return hwirq;
128 }
129
130 virq = irq_create_mapping(msi_mpic->irqhost, hwirq);
131 if (virq == NO_IRQ) {
132 pr_debug("u3msi: failed mapping hwirq 0x%lx\n", hwirq);
133 mpic_msi_free_hwirqs(msi_mpic, hwirq, 1);
134 return -ENOSPC;
135 }
136
137 set_irq_msi(virq, entry);
138 set_irq_chip(virq, &mpic_u3msi_chip);
139 set_irq_type(virq, IRQ_TYPE_EDGE_RISING);
140
141 pr_debug("u3msi: allocated virq 0x%x (hw 0x%lx) addr 0x%lx\n",
142 virq, hwirq, addr);
143
144 msg.data = hwirq;
145 write_msi_msg(virq, &msg);
146
147 hwirq++;
148 }
149
150 return 0;
151}
152
153int mpic_u3msi_init(struct mpic *mpic)
154{
155 int rc;
156
157 rc = mpic_msi_init_allocator(mpic);
158 if (rc) {
159 pr_debug("u3msi: Error allocating bitmap!\n");
160 return rc;
161 }
162
163 pr_debug("u3msi: Registering MPIC U3 MSI callbacks.\n");
164
165 BUG_ON(msi_mpic);
166 msi_mpic = mpic;
167
168 WARN_ON(ppc_md.setup_msi_irqs);
169 ppc_md.setup_msi_irqs = u3msi_setup_msi_irqs;
170 ppc_md.teardown_msi_irqs = u3msi_teardown_msi_irqs;
171 ppc_md.msi_check_device = u3msi_msi_check_device;
172
173 return 0;
174}