xref: /openbmc/linux/arch/m68k/amiga/chipram.c (revision df2634f43f5106947f3735a0b61a6527a4b278cd)
1 /*
2 **  linux/amiga/chipram.c
3 **
4 **      Modified 03-May-94 by Geert Uytterhoeven <geert@linux-m68k.org>
5 **          - 64-bit aligned allocations for full AGA compatibility
6 **
7 **	Rewritten 15/9/2000 by Geert to use resource management
8 */
9 
10 #include <linux/types.h>
11 #include <linux/kernel.h>
12 #include <linux/mm.h>
13 #include <linux/init.h>
14 #include <linux/ioport.h>
15 #include <linux/slab.h>
16 #include <linux/string.h>
17 #include <linux/module.h>
18 
19 #include <asm/page.h>
20 #include <asm/amigahw.h>
21 
22 unsigned long amiga_chip_size;
23 EXPORT_SYMBOL(amiga_chip_size);
24 
25 static struct resource chipram_res = {
26     .name = "Chip RAM", .start = CHIP_PHYSADDR
27 };
28 static unsigned long chipavail;
29 
30 
31 void __init amiga_chip_init(void)
32 {
33     if (!AMIGAHW_PRESENT(CHIP_RAM))
34 	return;
35 
36     /*
37      *  Remove the first 4 pages where PPC exception handlers will be located
38      */
39     amiga_chip_size -= 0x4000;
40     chipram_res.end = amiga_chip_size-1;
41     request_resource(&iomem_resource, &chipram_res);
42 
43     chipavail = amiga_chip_size;
44 }
45 
46 
47 void *amiga_chip_alloc(unsigned long size, const char *name)
48 {
49     struct resource *res;
50 
51     /* round up */
52     size = PAGE_ALIGN(size);
53 
54 #ifdef DEBUG
55     printk("amiga_chip_alloc: allocate %ld bytes\n", size);
56 #endif
57     res = kzalloc(sizeof(struct resource), GFP_KERNEL);
58     if (!res)
59 	return NULL;
60     res->name = name;
61 
62     if (allocate_resource(&chipram_res, res, size, 0, UINT_MAX, PAGE_SIZE, NULL, NULL) < 0) {
63 	kfree(res);
64 	return NULL;
65     }
66     chipavail -= size;
67 #ifdef DEBUG
68     printk("amiga_chip_alloc: returning %lx\n", res->start);
69 #endif
70     return (void *)ZTWO_VADDR(res->start);
71 }
72 EXPORT_SYMBOL(amiga_chip_alloc);
73 
74 
75     /*
76      *  Warning:
77      *  amiga_chip_alloc_res is meant only for drivers that need to allocate
78      *  Chip RAM before kmalloc() is functional. As a consequence, those
79      *  drivers must not free that Chip RAM afterwards.
80      */
81 
82 void * __init amiga_chip_alloc_res(unsigned long size, struct resource *res)
83 {
84     unsigned long start;
85 
86     /* round up */
87     size = PAGE_ALIGN(size);
88     /* dmesg into chipmem prefers memory at the safe end */
89     start = CHIP_PHYSADDR + chipavail - size;
90 
91 #ifdef DEBUG
92     printk("amiga_chip_alloc_res: allocate %ld bytes\n", size);
93 #endif
94     if (allocate_resource(&chipram_res, res, size, start, UINT_MAX, PAGE_SIZE, NULL, NULL) < 0) {
95 	printk("amiga_chip_alloc_res: first alloc failed!\n");
96 	if (allocate_resource(&chipram_res, res, size, 0, UINT_MAX, PAGE_SIZE, NULL, NULL) < 0)
97 	    return NULL;
98     }
99     chipavail -= size;
100 #ifdef DEBUG
101     printk("amiga_chip_alloc_res: returning %lx\n", res->start);
102 #endif
103     return (void *)ZTWO_VADDR(res->start);
104 }
105 
106 void amiga_chip_free(void *ptr)
107 {
108     unsigned long start = ZTWO_PADDR(ptr);
109     struct resource **p, *res;
110     unsigned long size;
111 
112     for (p = &chipram_res.child; (res = *p); p = &res->sibling) {
113 	if (res->start != start)
114 	    continue;
115 	*p = res->sibling;
116 	size = res->end-start;
117 #ifdef DEBUG
118 	printk("amiga_chip_free: free %ld bytes at %p\n", size, ptr);
119 #endif
120 	chipavail += size;
121 	kfree(res);
122 	return;
123     }
124     printk("amiga_chip_free: trying to free nonexistent region at %p\n", ptr);
125 }
126 EXPORT_SYMBOL(amiga_chip_free);
127 
128 
129 unsigned long amiga_chip_avail(void)
130 {
131 #ifdef DEBUG
132 	printk("amiga_chip_avail : %ld bytes\n", chipavail);
133 #endif
134 	return chipavail;
135 }
136 EXPORT_SYMBOL(amiga_chip_avail);
137 
138