xref: /openbmc/linux/arch/m68k/amiga/chipram.c (revision 588b48ca)
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/atomic.h>
20 #include <asm/page.h>
21 #include <asm/amigahw.h>
22 
23 unsigned long amiga_chip_size;
24 EXPORT_SYMBOL(amiga_chip_size);
25 
26 static struct resource chipram_res = {
27 	.name = "Chip RAM", .start = CHIP_PHYSADDR
28 };
29 static atomic_t chipavail;
30 
31 
32 void __init amiga_chip_init(void)
33 {
34 	if (!AMIGAHW_PRESENT(CHIP_RAM))
35 		return;
36 
37 	chipram_res.end = CHIP_PHYSADDR + amiga_chip_size - 1;
38 	request_resource(&iomem_resource, &chipram_res);
39 
40 	atomic_set(&chipavail, amiga_chip_size);
41 }
42 
43 
44 void *amiga_chip_alloc(unsigned long size, const char *name)
45 {
46 	struct resource *res;
47 	void *p;
48 
49 	res = kzalloc(sizeof(struct resource), GFP_KERNEL);
50 	if (!res)
51 		return NULL;
52 
53 	res->name = name;
54 	p = amiga_chip_alloc_res(size, res);
55 	if (!p) {
56 		kfree(res);
57 		return NULL;
58 	}
59 
60 	return p;
61 }
62 EXPORT_SYMBOL(amiga_chip_alloc);
63 
64 
65 	/*
66 	 *  Warning:
67 	 *  amiga_chip_alloc_res is meant only for drivers that need to
68 	 *  allocate Chip RAM before kmalloc() is functional. As a consequence,
69 	 *  those drivers must not free that Chip RAM afterwards.
70 	 */
71 
72 void *amiga_chip_alloc_res(unsigned long size, struct resource *res)
73 {
74 	int error;
75 
76 	/* round up */
77 	size = PAGE_ALIGN(size);
78 
79 	pr_debug("amiga_chip_alloc_res: allocate %lu bytes\n", size);
80 	error = allocate_resource(&chipram_res, res, size, 0, UINT_MAX,
81 				  PAGE_SIZE, NULL, NULL);
82 	if (error < 0) {
83 		pr_err("amiga_chip_alloc_res: allocate_resource() failed %d!\n",
84 		       error);
85 		return NULL;
86 	}
87 
88 	atomic_sub(size, &chipavail);
89 	pr_debug("amiga_chip_alloc_res: returning %pR\n", res);
90 	return ZTWO_VADDR(res->start);
91 }
92 
93 void amiga_chip_free(void *ptr)
94 {
95 	unsigned long start = ZTWO_PADDR(ptr);
96 	struct resource *res;
97 	unsigned long size;
98 
99 	res = lookup_resource(&chipram_res, start);
100 	if (!res) {
101 		pr_err("amiga_chip_free: trying to free nonexistent region at "
102 		       "%p\n", ptr);
103 		return;
104 	}
105 
106 	size = resource_size(res);
107 	pr_debug("amiga_chip_free: free %lu bytes at %p\n", size, ptr);
108 	atomic_add(size, &chipavail);
109 	release_resource(res);
110 	kfree(res);
111 }
112 EXPORT_SYMBOL(amiga_chip_free);
113 
114 
115 unsigned long amiga_chip_avail(void)
116 {
117 	unsigned long n = atomic_read(&chipavail);
118 
119 	pr_debug("amiga_chip_avail : %lu bytes\n", n);
120 	return n;
121 }
122 EXPORT_SYMBOL(amiga_chip_avail);
123 
124