Merge branch 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes...
[linux-2.6] / arch / powerpc / sysdev / mpic_msi.c
1 /*
2  * Copyright 2006-2007, Michael Ellerman, IBM Corporation.
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public License
6  * as published by the Free Software Foundation; version 2 of the
7  * License.
8  *
9  */
10
11 #include <linux/irq.h>
12 #include <linux/bitmap.h>
13 #include <linux/msi.h>
14 #include <asm/mpic.h>
15 #include <asm/prom.h>
16 #include <asm/hw_irq.h>
17 #include <asm/ppc-pci.h>
18
19 #include <sysdev/mpic.h>
20
21 static void __mpic_msi_reserve_hwirq(struct mpic *mpic, irq_hw_number_t hwirq)
22 {
23         pr_debug("mpic: reserving hwirq 0x%lx\n", hwirq);
24         bitmap_allocate_region(mpic->hwirq_bitmap, hwirq, 0);
25 }
26
27 void mpic_msi_reserve_hwirq(struct mpic *mpic, irq_hw_number_t hwirq)
28 {
29         unsigned long flags;
30
31         /* The mpic calls this even when there is no allocator setup */
32         if (!mpic->hwirq_bitmap)
33                 return;
34
35         spin_lock_irqsave(&mpic->bitmap_lock, flags);
36         __mpic_msi_reserve_hwirq(mpic, hwirq);
37         spin_unlock_irqrestore(&mpic->bitmap_lock, flags);
38 }
39
40 irq_hw_number_t mpic_msi_alloc_hwirqs(struct mpic *mpic, int num)
41 {
42         unsigned long flags;
43         int offset, order = get_count_order(num);
44
45         spin_lock_irqsave(&mpic->bitmap_lock, flags);
46         /*
47          * This is fast, but stricter than we need. We might want to add
48          * a fallback routine which does a linear search with no alignment.
49          */
50         offset = bitmap_find_free_region(mpic->hwirq_bitmap, mpic->irq_count,
51                                          order);
52         spin_unlock_irqrestore(&mpic->bitmap_lock, flags);
53
54         pr_debug("mpic: allocated 0x%x (2^%d) at offset 0x%x\n",
55                  num, order, offset);
56
57         return offset;
58 }
59
60 void mpic_msi_free_hwirqs(struct mpic *mpic, int offset, int num)
61 {
62         unsigned long flags;
63         int order = get_count_order(num);
64
65         pr_debug("mpic: freeing 0x%x (2^%d) at offset 0x%x\n",
66                  num, order, offset);
67
68         spin_lock_irqsave(&mpic->bitmap_lock, flags);
69         bitmap_release_region(mpic->hwirq_bitmap, offset, order);
70         spin_unlock_irqrestore(&mpic->bitmap_lock, flags);
71 }
72
73 #ifdef CONFIG_MPIC_U3_HT_IRQS
74 static int mpic_msi_reserve_u3_hwirqs(struct mpic *mpic)
75 {
76         irq_hw_number_t hwirq;
77         struct irq_host_ops *ops = mpic->irqhost->ops;
78         struct device_node *np;
79         int flags, index, i;
80         struct of_irq oirq;
81
82         pr_debug("mpic: found U3, guessing msi allocator setup\n");
83
84         /* Reserve source numbers we know are reserved in the HW */
85         for (i = 0;   i < 8;   i++)
86                 __mpic_msi_reserve_hwirq(mpic, i);
87
88         for (i = 42;  i < 46;  i++)
89                 __mpic_msi_reserve_hwirq(mpic, i);
90
91         for (i = 100; i < 105; i++)
92                 __mpic_msi_reserve_hwirq(mpic, i);
93
94         np = NULL;
95         while ((np = of_find_all_nodes(np))) {
96                 pr_debug("mpic: mapping hwirqs for %s\n", np->full_name);
97
98                 index = 0;
99                 while (of_irq_map_one(np, index++, &oirq) == 0) {
100                         ops->xlate(mpic->irqhost, NULL, oirq.specifier,
101                                                 oirq.size, &hwirq, &flags);
102                         __mpic_msi_reserve_hwirq(mpic, hwirq);
103                 }
104         }
105
106         return 0;
107 }
108 #else
109 static int mpic_msi_reserve_u3_hwirqs(struct mpic *mpic)
110 {
111         return -1;
112 }
113 #endif
114
115 static int mpic_msi_reserve_dt_hwirqs(struct mpic *mpic)
116 {
117         int i, len;
118         const u32 *p;
119
120         p = of_get_property(mpic->irqhost->of_node,
121                             "msi-available-ranges", &len);
122         if (!p) {
123                 pr_debug("mpic: no msi-available-ranges property found on %s\n",
124                           mpic->irqhost->of_node->full_name);
125                 return -ENODEV;
126         }
127
128         if (len % 8 != 0) {
129                 printk(KERN_WARNING "mpic: Malformed msi-available-ranges "
130                        "property on %s\n", mpic->irqhost->of_node->full_name);
131                 return -EINVAL;
132         }
133
134         bitmap_allocate_region(mpic->hwirq_bitmap, 0,
135                                get_count_order(mpic->irq_count));
136
137         /* Format is: (<u32 start> <u32 count>)+ */
138         len /= sizeof(u32);
139         for (i = 0; i < len / 2; i++, p += 2)
140                 mpic_msi_free_hwirqs(mpic, *p, *(p + 1));
141
142         return 0;
143 }
144
145 int mpic_msi_init_allocator(struct mpic *mpic)
146 {
147         int rc, size;
148
149         BUG_ON(mpic->hwirq_bitmap);
150         spin_lock_init(&mpic->bitmap_lock);
151
152         size = BITS_TO_LONGS(mpic->irq_count) * sizeof(long);
153         pr_debug("mpic: allocator bitmap size is 0x%x bytes\n", size);
154
155         mpic->hwirq_bitmap = alloc_maybe_bootmem(size, GFP_KERNEL);
156
157         if (!mpic->hwirq_bitmap) {
158                 pr_debug("mpic: ENOMEM allocating allocator bitmap!\n");
159                 return -ENOMEM;
160         }
161
162         memset(mpic->hwirq_bitmap, 0, size);
163
164         rc = mpic_msi_reserve_dt_hwirqs(mpic);
165         if (rc) {
166                 if (mpic->flags & MPIC_U3_HT_IRQS)
167                         rc = mpic_msi_reserve_u3_hwirqs(mpic);
168
169                 if (rc)
170                         goto out_free;
171         }
172
173         return 0;
174
175  out_free:
176         if (mem_init_done)
177                 kfree(mpic->hwirq_bitmap);
178
179         mpic->hwirq_bitmap = NULL;
180         return rc;
181 }