avoid endless loops in lib/swiotlb.c
[wrt350n-kernel.git] / arch / m68k / amiga / chipram.c
blobcbe36538af47be5cd2914fe7172ad2ea0f96c026
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 */
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 <linux/module.h>
18 #include <asm/page.h>
19 #include <asm/amigahw.h>
21 unsigned long amiga_chip_size;
22 EXPORT_SYMBOL(amiga_chip_size);
24 static struct resource chipram_res = {
25 .name = "Chip RAM", .start = CHIP_PHYSADDR
27 static unsigned long chipavail;
30 void __init amiga_chip_init(void)
32 if (!AMIGAHW_PRESENT(CHIP_RAM))
33 return;
36 * Remove the first 4 pages where PPC exception handlers will be located
38 amiga_chip_size -= 0x4000;
39 chipram_res.end = amiga_chip_size-1;
40 request_resource(&iomem_resource, &chipram_res);
42 chipavail = amiga_chip_size;
46 void *amiga_chip_alloc(unsigned long size, const char *name)
48 struct resource *res;
50 /* round up */
51 size = PAGE_ALIGN(size);
53 #ifdef DEBUG
54 printk("amiga_chip_alloc: allocate %ld bytes\n", size);
55 #endif
56 res = kzalloc(sizeof(struct resource), GFP_KERNEL);
57 if (!res)
58 return NULL;
59 res->name = name;
61 if (allocate_resource(&chipram_res, res, size, 0, UINT_MAX, PAGE_SIZE, NULL, NULL) < 0) {
62 kfree(res);
63 return NULL;
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);
71 EXPORT_SYMBOL(amiga_chip_alloc);
75 * Warning:
76 * amiga_chip_alloc_res is meant only for drivers that need to allocate
77 * Chip RAM before kmalloc() is functional. As a consequence, those
78 * drivers must not free that Chip RAM afterwards.
81 void * __init amiga_chip_alloc_res(unsigned long size, struct resource *res)
83 unsigned long start;
85 /* round up */
86 size = PAGE_ALIGN(size);
87 /* dmesg into chipmem prefers memory at the safe end */
88 start = CHIP_PHYSADDR + chipavail - size;
90 #ifdef DEBUG
91 printk("amiga_chip_alloc_res: allocate %ld bytes\n", size);
92 #endif
93 if (allocate_resource(&chipram_res, res, size, start, UINT_MAX, PAGE_SIZE, NULL, NULL) < 0) {
94 printk("amiga_chip_alloc_res: first alloc failed!\n");
95 if (allocate_resource(&chipram_res, res, size, 0, UINT_MAX, PAGE_SIZE, NULL, NULL) < 0)
96 return NULL;
98 chipavail -= size;
99 #ifdef DEBUG
100 printk("amiga_chip_alloc_res: returning %lx\n", res->start);
101 #endif
102 return (void *)ZTWO_VADDR(res->start);
105 void amiga_chip_free(void *ptr)
107 unsigned long start = ZTWO_PADDR(ptr);
108 struct resource **p, *res;
109 unsigned long size;
111 for (p = &chipram_res.child; (res = *p); p = &res->sibling) {
112 if (res->start != start)
113 continue;
114 *p = res->sibling;
115 size = res->end-start;
116 #ifdef DEBUG
117 printk("amiga_chip_free: free %ld bytes at %p\n", size, ptr);
118 #endif
119 chipavail += size;
120 kfree(res);
121 return;
123 printk("amiga_chip_free: trying to free nonexistent region at %p\n", ptr);
125 EXPORT_SYMBOL(amiga_chip_free);
128 unsigned long amiga_chip_avail(void)
130 #ifdef DEBUG
131 printk("amiga_chip_avail : %ld bytes\n", chipavail);
132 #endif
133 return chipavail;
135 EXPORT_SYMBOL(amiga_chip_avail);