1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 ** linux/amiga/chipram.c
4 **
5 ** Modified 03-May-94 by Geert Uytterhoeven <geert@linux-m68k.org>
6 ** - 64-bit aligned allocations for full AGA compatibility
7 **
8 ** Rewritten 15/9/2000 by Geert to use resource management
9 */
10
11 #include <linux/types.h>
12 #include <linux/kernel.h>
13 #include <linux/mm.h>
14 #include <linux/init.h>
15 #include <linux/ioport.h>
16 #include <linux/slab.h>
17 #include <linux/string.h>
18 #include <linux/module.h>
19
20 #include <asm/atomic.h>
21 #include <asm/page.h>
22 #include <asm/amigahw.h>
23
24 unsigned long amiga_chip_size;
25 EXPORT_SYMBOL(amiga_chip_size);
26
27 static struct resource chipram_res = {
28 .name = "Chip RAM", .start = CHIP_PHYSADDR
29 };
30 static atomic_t chipavail;
31
32
33 void __init amiga_chip_init(void)
34 {
35 if (!AMIGAHW_PRESENT(CHIP_RAM))
36 return;
37
38 chipram_res.end = CHIP_PHYSADDR + amiga_chip_size - 1;
39 request_resource(&iomem_resource, &chipram_res);
40
41 atomic_set(&chipavail, amiga_chip_size);
42 }
43
44
45 void *amiga_chip_alloc(unsigned long size, const char *name)
46 {
47 struct resource *res;
48 void *p;
49
50 res = kzalloc(sizeof(struct resource), GFP_KERNEL);
51 if (!res)
52 return NULL;
53
54 res->name = name;
55 p = amiga_chip_alloc_res(size, res);
56 if (!p) {
57 kfree(res);
58 return NULL;
59 }
60
61 return p;
62 }
63 EXPORT_SYMBOL(amiga_chip_alloc);
64
65
66 /*
67 * Warning:
68 * amiga_chip_alloc_res is meant only for drivers that need to
69 * allocate Chip RAM before kmalloc() is functional. As a consequence,
70 * those drivers must not free that Chip RAM afterwards.
71 */
72
73 void *amiga_chip_alloc_res(unsigned long size, struct resource *res)
74 {
75 int error;
76
77 /* round up */
78 size = PAGE_ALIGN(size);
79
80 pr_debug("amiga_chip_alloc_res: allocate %lu bytes\n", size);
81 error = allocate_resource(&chipram_res, res, size, 0, UINT_MAX,
82 PAGE_SIZE, NULL, NULL);
83 if (error < 0) {
84 pr_err("amiga_chip_alloc_res: allocate_resource() failed %d!\n",
85 error);
86 return NULL;
87 }
88
89 atomic_sub(size, &chipavail);
90 pr_debug("amiga_chip_alloc_res: returning %pR\n", res);
91 return ZTWO_VADDR(res->start);
92 }
93
94 void amiga_chip_free(void *ptr)
95 {
96 unsigned long start = ZTWO_PADDR(ptr);
97 struct resource *res;
98 unsigned long size;
99
100 res = lookup_resource(&chipram_res, start);
101 if (!res) {
102 pr_err("amiga_chip_free: trying to free nonexistent region at "
103 "%p\n", ptr);
104 return;
105 }
106
107 size = resource_size(res);
108 pr_debug("amiga_chip_free: free %lu bytes at %p\n", size, ptr);
109 atomic_add(size, &chipavail);
110 release_resource(res);
111 kfree(res);
112 }
113 EXPORT_SYMBOL(amiga_chip_free);
114
115
116 unsigned long amiga_chip_avail(void)
117 {
118 unsigned long n = atomic_read(&chipavail);
119
120 pr_debug("amiga_chip_avail : %lu bytes\n", n);
121 return n;
122 }
123 EXPORT_SYMBOL(amiga_chip_avail);
124
125
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