Merge branch 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-arm
[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/bootmem.h>
13 #include <linux/bitmap.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
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->of_node, "msi-available-ranges", &len);
121         if (!p) {
122                 pr_debug("mpic: no msi-available-ranges property found on %s\n",
123                           mpic->of_node->full_name);
124                 return -ENODEV;
125         }
126
127         if (len % 8 != 0) {
128                 printk(KERN_WARNING "mpic: Malformed msi-available-ranges "
129                        "property on %s\n", mpic->of_node->full_name);
130                 return -EINVAL;
131         }
132
133         bitmap_allocate_region(mpic->hwirq_bitmap, 0,
134                                get_count_order(mpic->irq_count));
135
136         /* Format is: (<u32 start> <u32 count>)+ */
137         len /= sizeof(u32);
138         for (i = 0; i < len / 2; i++, p += 2)
139                 mpic_msi_free_hwirqs(mpic, *p, *(p + 1));
140
141         return 0;
142 }
143
144 int mpic_msi_init_allocator(struct mpic *mpic)
145 {
146         int rc, size;
147
148         BUG_ON(mpic->hwirq_bitmap);
149         spin_lock_init(&mpic->bitmap_lock);
150
151         size = BITS_TO_LONGS(mpic->irq_count) * sizeof(long);
152         pr_debug("mpic: allocator bitmap size is 0x%x bytes\n", size);
153
154         if (mem_init_done)
155                 mpic->hwirq_bitmap = kmalloc(size, GFP_KERNEL);
156         else
157                 mpic->hwirq_bitmap = alloc_bootmem(size);
158
159         if (!mpic->hwirq_bitmap) {
160                 pr_debug("mpic: ENOMEM allocating allocator bitmap!\n");
161                 return -ENOMEM;
162         }
163
164         memset(mpic->hwirq_bitmap, 0, size);
165
166         rc = mpic_msi_reserve_dt_hwirqs(mpic);
167         if (rc) {
168                 if (mpic->flags & MPIC_U3_HT_IRQS)
169                         rc = mpic_msi_reserve_u3_hwirqs(mpic);
170
171                 if (rc)
172                         goto out_free;
173         }
174
175         return 0;
176
177  out_free:
178         if (mem_init_done)
179                 kfree(mpic->hwirq_bitmap);
180
181         mpic->hwirq_bitmap = NULL;
182         return rc;
183 }