xref: /linux/arch/m68k/amiga/chipram.c (revision 14b42963f64b98ab61fa9723c03d71aa5ef4f862)
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/init.h>
13 #include <linux/ioport.h>
14 #include <linux/slab.h>
15 #include <linux/string.h>
16 #include <asm/page.h>
17 #include <asm/amigahw.h>
18 
19 unsigned long amiga_chip_size;
20 
21 static struct resource chipram_res = {
22     .name = "Chip RAM", .start = CHIP_PHYSADDR
23 };
24 static unsigned long chipavail;
25 
26 
27 void __init amiga_chip_init(void)
28 {
29     if (!AMIGAHW_PRESENT(CHIP_RAM))
30 	return;
31 
32 #ifndef CONFIG_APUS_FAST_EXCEPT
33     /*
34      *  Remove the first 4 pages where PPC exception handlers will be located
35      */
36     amiga_chip_size -= 0x4000;
37 #endif
38     chipram_res.end = amiga_chip_size-1;
39     request_resource(&iomem_resource, &chipram_res);
40 
41     chipavail = amiga_chip_size;
42 }
43 
44 
45 void *amiga_chip_alloc(unsigned long size, const char *name)
46 {
47     struct resource *res;
48 
49     /* round up */
50     size = PAGE_ALIGN(size);
51 
52 #ifdef DEBUG
53     printk("amiga_chip_alloc: allocate %ld bytes\n", size);
54 #endif
55     res = kmalloc(sizeof(struct resource), GFP_KERNEL);
56     if (!res)
57 	return NULL;
58     memset(res, 0, sizeof(struct resource));
59     res->name = name;
60 
61     if (allocate_resource(&chipram_res, res, size, 0, UINT_MAX, PAGE_SIZE, NULL, NULL) < 0) {
62 	kfree(res);
63 	return NULL;
64     }
65     chipavail -= size;
66 #ifdef DEBUG
67     printk("amiga_chip_alloc: returning %lx\n", res->start);
68 #endif
69     return (void *)ZTWO_VADDR(res->start);
70 }
71 
72 
73     /*
74      *  Warning:
75      *  amiga_chip_alloc_res is meant only for drivers that need to allocate
76      *  Chip RAM before kmalloc() is functional. As a consequence, those
77      *  drivers must not free that Chip RAM afterwards.
78      */
79 
80 void * __init amiga_chip_alloc_res(unsigned long size, struct resource *res)
81 {
82     unsigned long start;
83 
84     /* round up */
85     size = PAGE_ALIGN(size);
86     /* dmesg into chipmem prefers memory at the safe end */
87     start = CHIP_PHYSADDR + chipavail - size;
88 
89 #ifdef DEBUG
90     printk("amiga_chip_alloc_res: allocate %ld bytes\n", size);
91 #endif
92     if (allocate_resource(&chipram_res, res, size, start, UINT_MAX, PAGE_SIZE, NULL, NULL) < 0) {
93 	printk("amiga_chip_alloc_res: first alloc failed!\n");
94 	if (allocate_resource(&chipram_res, res, size, 0, UINT_MAX, PAGE_SIZE, NULL, NULL) < 0)
95 	    return NULL;
96     }
97     chipavail -= size;
98 #ifdef DEBUG
99     printk("amiga_chip_alloc_res: returning %lx\n", res->start);
100 #endif
101     return (void *)ZTWO_VADDR(res->start);
102 }
103 
104 void amiga_chip_free(void *ptr)
105 {
106     unsigned long start = ZTWO_PADDR(ptr);
107     struct resource **p, *res;
108     unsigned long size;
109 
110     for (p = &chipram_res.child; (res = *p); p = &res->sibling) {
111 	if (res->start != start)
112 	    continue;
113 	*p = res->sibling;
114 	size = res->end-start;
115 #ifdef DEBUG
116 	printk("amiga_chip_free: free %ld bytes at %p\n", size, ptr);
117 #endif
118 	chipavail += size;
119 	kfree(res);
120 	return;
121     }
122     printk("amiga_chip_free: trying to free nonexistent region at %p\n", ptr);
123 }
124 
125 
126 unsigned long amiga_chip_avail(void)
127 {
128 #ifdef DEBUG
129 	printk("amiga_chip_avail : %ld bytes\n", chipavail);
130 #endif
131 	return chipavail;
132 }
133